Ecological insights from three decades of animal movement tracking across a changing Arctic
Davidson, Sarah C. ; Bohrer, Gil ; Gurarie, Eliezer ; LaPoint, Scott ; Mahoney, Peter J. ; Boelman, Natalie T. ; Eitel, Jan U.H. ; Prugh, Laura R. ; Vierling, Lee A. ; Jennewein, Jyoti ; Grier, Emma ; Couriot, Ophélie ; Kelly, Allicia P. ; Meddens, Arjan J.H. ; Oliver, Ruth Y. ; Kays, Roland ; Wikelski, Martin ; Aarvak, Tomas ; Ackerman, Joshua T. ; Alves, José A. ; Bayne, Erin ; Bedrosian, Bryan ; Belant, Jerrold L. ; Berdahl, Andrew M. ; Berlin, Alicia M. ; Berteaux, Dominique ; Bêty, Joël ; Boiko, Dmitrijs ; Booms, Travis L. ; Borg, Bridget L. ; Boutin, Stan ; Boyd, Sean ; Brides, Kane ; Brown, Stephen ; Bulyuk, Victor N. ; Burnham, Kurt K. ; Cabot, David ; Casazza, Michael ; Christie, Katherine ; Craig, Erica H. ; Davis, Shanti E. ; Davison, Tracy ; Demma, Dominic ; DeSorbo, Christopher R. ; Dixon, Andrew ; Domenech, Robert ; Eichhorn, Götz ; Elliott, Kyle ; Evenson, Joseph R. ; Exo, Klaus Michael ; Ferguson, Steven H. ; Fiedler, Wolfgang ; Fisk, Aaron ; Fort, Jérôme ; Franke, Alastair ; Fuller, Mark R. ; Garthe, Stefan ; Gauthier, Gilles ; Gilchrist, Grant ; Glazov, Petr ; Gray, Carrie E. ; Grémillet, David ; Griffin, Larry ; Hallworth, Michael T. ; Harrison, Autumn Lynn ; Hennin, Holly L. ; Hipfner, Mark ; Hodson, James ; Johnson, James A. ; Joly, Kyle ; Jones, Kimberly ; Katzner, Todd E. ; Kidd, Jeff W. ; Knight, Elly C. ; Kochert, Michael N. ; Kölzsch, Andrea ; Kruckenberg, Helmut ; Lagassé, Benjamin J. ; Lai, Sandra ; Lamarre, Jean François ; Lanctot, Richard B. ; Larter, Nicholas C. ; Latham, A.D.M. ; Latty, Christopher J. ; Lawler, James P. ; Léandri-Breton, Don Jean ; Lee, Hansoo ; Lewis, Stephen B. ; Love, Oliver P. ; Madsen, Jesper ; Maftei, Mark ; Mallory, Mark L. ; Mangipane, Buck ; Markovets, Mikhail Y. ; Marra, Peter P. ; McGuire, Rebecca ; McIntyre, Carol L. ; McKinnon, Emily A. ; Miller, Tricia A. ; Moonen, Sander ; Mu, Tong ; Müskens, Gerhard J.D.M. ; Ng, Janet ; Nicholson, Kerry L. ; Øien, Ingar Jostein ; Overton, Cory ; Owen, Patricia A. ; Patterson, Allison ; Petersen, Aevar ; Pokrovsky, Ivan ; Powell, Luke L. ; Prieto, Rui ; Quillfeldt, Petra ; Rausch, Jennie ; Russell, Kelsey ; Saalfeld, Sarah T. ; Schekkerman, Hans ; Schmutz, Joel A. ; Schwemmer, Philipp ; Seip, Dale R. ; Shreading, Adam ; Silva, Mónica A. ; Smith, Brian W. ; Smith, Fletcher ; Smith, Jeff P. ; Snell, Katherine R.S. ; Sokolov, Aleksandr ; Sokolov, Vasiliy ; Solovyeva, Diana V. ; Sorum, Mathew S. ; Tertitski, Grigori ; Therrien, J.F. ; Thorup, Kasper ; Tibbitts, Lee ; Tulp, Ingrid ; Uher-Koch, Brian D. ; Bemmelen, Rob S.A. van; Wilgenburg, Steven Van; Duyke, Andrew L. Von; Watson, Jesse L. ; Watts, Bryan D. ; Williams, Judy A. ; Wilson, Matthew T. ; Wright, James R. ; Yates, Michael A. ; Yurkowski, David J. ; Žydelis, Ramūnas ; Hebblewhite, Mark - \ 2020
Science 370 (2020)6517. - ISSN 0036-8075 - p. 712 - 715.
The Arctic is entering a new ecological state, with alarming consequences for humanity. Animal-borne sensors offer a window into these changes. Although substantial animal tracking data from the Arctic and subarctic exist, most are difficult to discover and access. Here, we present the new Arctic Animal Movement Archive (AAMA), a growing collection of more than 200 standardized terrestrial and marine animal tracking studies from 1991 to the present. The AAMA supports public data discovery, preserves fundamental baseline data for the future, and facilitates efficient, collaborative data analysis. With AAMA-based case studies, we document climatic influences on the migration phenology of eagles, geographic differences in the adaptive response of caribou reproductive phenology to climate change, and species-specific changes in terrestrial mammal movement rates in response to increasing temperature.
Author Correction: Global status and conservation potential of reef sharks
MacNeil, M.A. ; Chapman, Demian D. ; Heupel, Michelle ; Simpfendorfer, Colin A. ; Heithaus, Michael ; Meekan, Mark ; Harvey, Euan ; Goetze, Jordan ; Kiszka, Jeremy ; Bond, Mark E. ; Currey-Randall, Leanne M. ; Speed, Conrad W. ; Sherman, C.S. ; Rees, Matthew J. ; Udyawer, Vinay ; Flowers, Kathryn I. ; Clementi, Gina ; Valentin-Albanese, Jasmine ; Gorham, Taylor ; Adam, M.S. ; Ali, Khadeeja ; Pina-Amargós, Fabián ; Angulo-Valdés, Jorge A. ; Asher, Jacob ; Barcia, Laura García ; Beaufort, Océane ; Benjamin, Cecilie ; Bernard, Anthony T.F. ; Berumen, Michael L. ; Bierwagen, Stacy ; Bonnema, Erika ; Bown, Rosalind M.K. ; Bradley, Darcy ; Brooks, Edd ; Brown, J.J. ; Buddo, Dayne ; Burke, Patrick ; Cáceres, Camila ; Cardeñosa, Diego ; Carrier, Jeffrey C. ; Caselle, Jennifer E. ; Charloo, Venkatesh ; Claverie, Thomas ; Clua, Eric ; Cochran, Jesse E.M. ; Cook, Neil ; Cramp, Jessica ; D’Alberto, Brooke ; Graaf, Martin de; Dornhege, Mareike ; Estep, Andy ; Fanovich, Lanya ; Farabaugh, Naomi F. ; Fernando, Daniel ; Flam, Anna L. ; Floros, Camilla ; Fourqurean, Virginia ; Garla, Ricardo ; Gastrich, Kirk ; George, Lachlan ; Graham, Rory ; Guttridge, Tristan ; Hardenstine, Royale S. ; Heck, Stephen ; Henderson, Aaron C. ; Hertler, Heidi ; Hueter, Robert ; Johnson, Mohini ; Jupiter, Stacy ; Kasana, Devanshi ; Kessel, Steven T. ; Kiilu, Benedict ; Kirata, Taratu ; Kuguru, Baraka ; Kyne, Fabian ; Langlois, Tim ; Lédée, Elodie J.I. ; Lindfield, Steve ; Luna-Acosta, Andrea ; Maggs, Jade ; Manjaji-Matsumoto, B.M. ; Marshall, Andrea ; Matich, Philip ; McCombs, Erin ; McLean, Dianne ; Meggs, Llewelyn ; Moore, Stephen ; Mukherji, Sushmita ; Murray, Ryan ; Kaimuddin, Muslimin ; Newman, Stephen J. ; Nogués, Josep ; Obota, Clay ; O’Shea, Owen ; Osuka, Kennedy ; Papastamatiou, Yannis P. ; Perera, Nishan ; Peterson, Bradley ; Ponzo, Alessandro ; Prasetyo, Andhika ; Sjamsul Quamar, L.M. ; Quinlan, Jessica ; Ruiz-Abierno, Alexei ; Sala, Enric ; Samoilys, Melita ; Schärer-Umpierre, Michelle ; Schlaff, Audrey ; Simpson, Nikola ; Smith, Adam N.H. ; Sparks, Lauren ; Tanna, Akshay ; Torres, Rubén ; Travers, Michael J. ; Zinnicq Bergmann, Maurits van; Vigliola, Laurent ; Ward, Juney ; Watts, Alexandra M. ; Wen, Colin ; Whitman, Elizabeth ; Wirsing, Aaron J. ; Wothke, Aljoscha ; Zarza-Gonzâlez, Esteban ; Cinner, Joshua E. - \ 2020
Nature 585 (2020). - ISSN 0028-0836 - p. E11 - E11.
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
Global status and conservation potential of reef sharks
MacNeil, Aaron ; Chapman, Demian D. ; Heupel, Michelle ; Simpfendorfer, Colin A. ; Heithaus, Michael ; Meekan, Mark ; Harvey, Euan ; Goetze, Jordan ; Kiszka, Jeremy ; Bond, Mark E. ; Currey-Randall, Leanne M. ; Speed, Conrad W. ; Sherman, Samantha ; Rees, Matthew J. ; Udyawer, Vinay ; Flowers, Kathryn I. ; Clementi, Gina ; Valentin-Albanese, Jasmine ; Gorham, Taylor ; Adam, Shiham ; Khadeeja, Ali ; Pina-Amargós, Fabián ; Angulo-Valdés, Jorge A. ; Asher, Jacob ; García Barcia, Laura ; Beaufort, Océane ; Benjamin, Cecilie ; Bernard, Anthony T.F. ; Berumen, Michael L. ; Bierwagen, Stacy ; Bonnema, Erika ; Bown, Rosalind M.K. ; Bradley, Darcey ; Brooks, Edd ; Brown, Jed ; Buddo, Dayne ; Burke, Patrick ; Cáceres, Camila ; Cardeñosa, Diego ; Carrier, Jeffrey C. ; Caselle, Jennifer E. ; Charloo, Venkatesh ; Claverie, Thomas ; Clua, Eric ; Cochran, Jesse E.M. ; Cook, Neil ; Cramp, Jessica ; D’Alberto, Brooke ; Graaf, Martin de; Dornhege, Mareike ; Estep, Andy ; Fanovich, Lanya ; Farabough, Naomi F. ; Fernando, Daniel ; Flam, Anna L. ; Floros, Camilla ; Fourqurean, Virginia ; Garla, Ricardo ; Gastrich, Kirk ; George, Lachlan ; Graham, Rory ; Guttridge, Tristan ; Hardenstine, Royale S. ; Heck, Stephen ; Henderson, Aaron C. ; Hertler, Heidi ; Hueter, Robert ; Johnson, Mohini ; Jupiter, Stacy ; Kasana, Devanshi ; Kessel, Steven T. ; Kiilu, Benedict ; Kirata, Taratu ; Kuguru, Baraka ; Kyne, Fabian ; Langlois, Tim ; Lédée, Elodie J.I. ; Lindfield, Steve ; Luna-Acosta, Andrea ; Maggs, Jade ; Manjaji-Matsumoto, Mabel ; Marshall, Andrea ; Matich, Philip ; McCombs, Erin ; McLean, Dianne ; Meggs, Llewelyn ; Moore, Stephen ; Mukherji, Sushmita ; Murray, Ryan ; Kaimuddin, Muslimin ; Newman, Stephen J. ; Nogués, Josep ; Obota, Clay ; O’Shea, Owen ; Osuka, Kennedy ; Papastamatiou, Yannis P. ; Perera, Nishan ; Peterson, Bradley ; Ponzo, Alessandro ; Prasetyo, Andhika ; Quamar, Sjamsul ; Quinlan, Jessica ; Ruiz-Abierno, Alexei ; Sala, Enric ; Samoilys, Melita ; Schärer-Umpierre, Michelle ; Schlaff, Audrey ; Simpson, Nikola ; Smith, Adam N.H. ; Sparks, Lauren ; Tanna, Akshay ; Torres, Rubén ; Travers, Michael J. ; Zinnicq Bergmann, Maurits van; Vigliola, Laurent ; Ward, Juney ; Watts, Alexandra M. ; Wen, Colin ; Whitman, Elizabeth ; Wirsing, Aaron J. ; Wothke, Aljoscha ; Zarza-Gonzâlez, Esteban ; Cinner, Joshua E. - \ 2020
Nature 583 (2020). - ISSN 0028-0836 - p. 801 - 806.
Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status1,2. Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats3. Here we address this knowledge gap using data from more than 15,000 standardized baited remote underwater video stations that were deployed on 371 reefs in 58 nations to estimate the conservation status of reef sharks globally. Our results reveal the profound impact that fishing has had on reef shark populations: we observed no sharks on almost 20% of the surveyed reefs. Reef sharks were almost completely absent from reefs in several nations, and shark depletion was strongly related to socio-economic conditions such as the size and proximity of the nearest market, poor governance and the density of the human population. However, opportunities for the conservation of reef sharks remain: shark sanctuaries, closed areas, catch limits and an absence of gillnets and longlines were associated with a substantially higher relative abundance of reef sharks. These results reveal several policy pathways for the restoration and management of reef shark populations, from direct top-down management of fishing to indirect improvement of governance conditions. Reef shark populations will only have a high chance of recovery by engaging key socio-economic aspects of tropical fisheries.
Spatial geochemistry influences the home range of elephants
Sach, Fiona ; Yon, Lisa ; Henley, Michelle D. ; Bedetti, Anka ; Buss, Peter ; Boer, Willem Frederik de; Dierenfeld, Ellen S. ; Gardner, Amanda ; Langley-Evans, Simon C. ; Hamilton, Elliott ; Lark, Murray ; Prins, Herbert H.T. ; Swemmer, Anthony M. ; Watts, Michael J. - \ 2020
Science of the Total Environment 729 (2020). - ISSN 0048-9697
Elephant movement - Loxodonta africana - Minerals - Mining - Potentially toxic elements
The unique geochemistry surrounding the Palabora Mining Company (PMC) land may act as a micronutrient hotspot, attracting elephants to the area. The PMC produces refined copper and extracts phosphates and other minerals. Understanding the spatial influence of geochemistry on the home range size of African elephants is important for elephant population management and conservation. The home ranges of collared elephants surrounding the PMC were significantly smaller (P = 0.001) than conspecifics in surrounding reserves, suggesting that their resource needs were met within these smaller areas. Environmental samples (soil, water and plants) were analysed from the mine area and along six transects radiating from the mine centre. Tail hair and faecal samples from elephants at the PMC, and conspecifics within the surrounding area were analysed. All samples were analysed for minerals essential to health and potentially toxic elements (PTEs; As, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se, U, V and Zn). Results show that the geochemistry at the PMC is different compared to surrounding areas, with significant elevations seen in all analysed minerals and PTEs in soil closer to the mine, thereby drawing the elephants to the area. Additionally significant elevations were seen in elements analysed in water and vegetation samples. Elephant tail hair from elephants at the mine was significantly greater in Cd, whilst Mg, P, Cu, As, Cd, Pb and U concentrations were significantly greater in elephant faecal samples at the mine compared to the non-mine samples. When micronutrient hotspots overlap with human activity (such as mining), this can lead to poor human-elephant coexistence and thus conflict. When managing elephant populations, the influence of mineral provision on elephant movement must be considered. Such detailed resource information can inform conservation efforts for coordinated programmes (UN SDGs 15 and 17) and underpin sustainable economic activity (UN SDG 8, 11 and 12).
Theoretical risk of genetic reassortment should not impede development of live, attenuated Rift Valley fever (RVF) vaccines commentary on the draft WHO RVF Target Product Profile
Monath, Thomas P. ; Kortekaas, Jeroen ; Watts, Douglas M. ; Christofferson, Rebecca C. ; Desiree LaBeaud, Angelle ; Gowen, Brian ; Peters, Clarence J. ; Smith, Darci R. ; Swanepoel, Robert ; Morrill, John C. ; Ksiazek, Thomas G. ; Pittman, Phillip R. ; Bird, Brian H. ; Bettinger, George - \ 2020
Vaccine: X 5 (2020). - ISSN 2590-1362
Genetic reassortment - Rift Valley Fever vaccine - Target Product Profile
In November 2019, The World Health Organization (WHO) issued a draft set of Target Product Profiles (TPPs) describing optimal and minimally acceptable targets for vaccines against Rift Valley fever (RVF), a Phlebovirus with a three segmented genome, in both humans and ruminants. The TPPs contained rigid requirements to protect against genomic reassortment of live, attenuated vaccines (LAVs) with wild-type RVF virus (RVFV), which place undue constraints on development and regulatory approval of LAVs. We review the current LAVs in use and in development, and conclude that there is no evidence that reassortment between LAVs and wild-type RVFV has occurred during field use, that such a reassortment event if it occurred would have no untoward consequence, and that the TPPs should be revised to provide a more balanced assessment of the benefits versus the theoretical risks of reassortment.
Impact of network topology on the stability of DC microgrids
Wienand, J.F. ; Eidmann, D. ; Kremers, J. ; Heitzig, J. ; Hellmann, F. ; Kurths, J. - \ 2019
Chaos 29 (2019)11. - ISSN 1054-1500
We probe the stability of Watts-Strogatz DC microgrids, in which droop-controlled producers and constant power load consumers are homogeneously distributed and obey Kirchhoff's circuit laws. The concept of survivability is employed to evaluate the system's response to Dirac-delta voltage perturbations at single nodes. A fixed point analysis of the power grid model yields that there is only one relevant attractor. Using a set of simulations with random networks, we investigate correlations between survivability and three topological network measures: the share of producers in the network and the degree and the average neighbor degree of the perturbed node. Depending on the imposed voltage and current limits, the stability is optimized for low node degrees or a specific share of producers. Based on our findings, we provide an insight into the local dynamics of the perturbed system and derive explicit guidelines for the design of resilient DC power grids.
Corrigendum: Exposure to antibiotics affects Saponin immersion-induced immune stimulation and shift in microbial composition in Zebrafish larvae
López Nadal, Adrià ; Peggs, David ; Wiegertjes, Geert F. ; Brugman, Sylvia - \ 2019
Frontiers in Microbiology 10 (2019). - ISSN 1664-302X
In the original article, there was an error. The name of the transgenic line used was incorrect. The correct name of the line is "mpeg1:mCherry/mpx:eGFPi114" Corrections have been made to the Materials and Methods subsection Animals: "Adult Tg(mpeg1:mCherry/mpx:eGFPi114) (Renshaw et al., 2006; Bernut et al., 2014) zebrafish (kindly provided by Prof. Meijer, Leiden University), expressing mCherry under the macrophage-specific mpeg1 promotor and GFP under the neutrophil-specific mpx promotor were housed in Zebtec family tanks (Tecniplast, Buguggiate, Italy) under continuous flow-through at 28°C (14/10-hour light/dark cycle) at Carus facilities (WUR, Wageningen, Netherlands). Zebrafish were fed with a mixture of Artemia 230.000 npg (Ocean Nutrition Europe, Essen, Belgium) and Tetramin Flakes (Tetra, Melle, Germany) twice per day. Embryos were obtained by natural spawning and raised with E3 water (0.10 mM NaCl in demineralized water, pH 7.6) in petri dishes at 28°C (12/12-hour light/dark cycle) (Westerfield, 2007). Dead or fungus-infected embryos were identified by microscopy and discarded in tricaine/E3 solution [8.4% (v/v) 24 mM Tricaine (Sigma-Aldrich, DL, United States) stock solution in E3]. Larval ages are expressed in days post-fertilization (dpf). From 5 dpf onward larvae were fed with live daily cultured Tetrahymena pyriformis." Materials and Methods, subsection Dose-Response Experiment Saponin Exposure: "Double Tg(mpeg1:mCherry /mpx:eGFPi114) zebrafish larvae were randomly distributed in 6 well plates (n = 20 fish/well) and exposed to different concentrations [0, 0.5, 0.7 and 1.0 mg/ml] of saponin [ultrapure Soy Saponin 95%, kindly provided by Trond Kortner NMBU Oslo Norway, origin: Organic Technologies, Coshocton, OH (Krogdahl et al., 2015)] dissolved in the E3 (10 ml solution/well) from 6-9 dpf. Mortality was registered and all media were refreshed daily. At 24 h (7 dpf) and 72 h (9 dpf) after the start of the immersion, zebrafish (n = 6-11/group) were anaesthetized embedded and imaged using fluorescent microscopy (as described below). Per time point several larvae were euthanized for further analysis with an overdose MS-222 (8.4 ml of 24 mM Tricaine (Sigma-Aldrich, DL, United States) in 100 ml E3). Pools of 5 larvae were used for RNA extraction (3 pools per group at 24 h, 7-9 pools per group at 72 h) and gene expression was measured on cDNA by Real Time PCR (as described below). Two independent experiments were performed and data were combined." Materials and Methods, subsection Fluorescent in vivo imaging: "Tg(mpeg1:mCherry/mpx:eGFPi114) zebrafish larvae were anaesthetized with tricaine/E3 solution (4.2 ml of 24 mM Tricaine (Sigma-Aldrich, DL, United States) in 100 ml E3) and embedded in 1% low melting point agarose (Thermo Fisher Scientific, MA, United States). Larvae were imaged as whole mounts with a Leica M205 FA Fluorescence Stereo Microscope. After image acquisition, pictures were analyzed with ImageJ® software (United States National Institutes of Health, Bethesda, United States). The intestinal regions were manually selected per fish on the basis of the bright light picture and subsequently copied to the green and red channel pictures (Supplementary Figure S1). Within this intestinal region individual cells were counted for each fish. Furthermore, corrected total cell fluorescence (CTCF) was measured in ImageJ® on total fish larvae by using the following formula: Integrated density-(area of total fish x mean fluorescence of the background reading)." Material and Methods, subsection Experimental Design and Sampling Strategy Antibiotics and Saponin Exposure: A graphical representation of the experimental design and analysis performed per time-point is displayed in Figure 1. To assess the effect of antibiotics, 4 dpf Tg(mpeg1:mCherry/mpx:eGFPi114) fish were randomly distributed in five 6 well-plates (n = 20 fish/well) and 3 treatment conditions were established: (1) control (E3), (2) ciprofloxacin 5 μg/L (Sigma-Aldrich, DL, United States) or (3) oxytetracycline hydrochloride 5 μg/L (Sigma-Aldrich, DL, United States) (10 ml solution/well). The dose of antibiotics was based on several reviews and experimental papers summarizing environmental concentrations of antibiotics in water environments (Ding and He, 2010; Carvalho and Santos, 2016; Watts et al., 2017; Patrolecco et al., 2018; Zhou et al., 2018b) to be at a low dose (ng-μg/L range) and not acute dose (mg/L range). At 6 dpf, 4 pools of 5 larvae were sampled to assess changes in gene expression at baseline. Moreover, at 6 dpf DNA was isolated from 3 pools of 5 larvae to investigate microbiome composition at baseline. In vivo imaging was performed on n = 10 larvae/group to visualize innate immune cells. Subsequently, after sampling, at 6 dpf ultrapure soy saponin was applied to half of the remaining larvae at a concentration 0.5 mg/ml (to induce mild immune stimulation) so each treatment group was split into two, resulting in 6 treatment groups: (1) control, (2) ciprofloxacin (5 μg/L), (3) oxytetracycline hydrochloride (5 μg/L), (4) saponin (0.5 mg/ml), (5) ciprofloxacin + saponin (5 μg/L + 0.5 mg/ml), and (6) oxytetracycline hydrochloride + saponin (5 μg/L + 0.5 mg/ml). All treatment media were refreshed daily. At 9 dpf in vivo imaging was performed on n = 10 larvae/group to visualize innate immune cells. Gene expression was performed on 4 pools of 5 larvae to investigate immune gene expression and from 3 pools of 5 larvae DNA was isolated for microbiological analysis. Because of the error reported above, corrections have also been made to the Figure legends of Figure 2 and Figure 4. The correct legends appear below. Figure 2: Effect of saponin immersion on zebrafish larvae. (A) Percent survival of zebrafish exposed to control (E3), 0.5 mg/ml saponin, 0.7 mg/ml saponin and 1 mg/ml saponin from 6-9 dpf (n = 40 fish/treatment) (Log-rank Mantel-Cox Test for Chi-square, ∗∗∗p < 0.0005). (B) Representative pictures of the saponin-treated Tg(mpeg1:mCherry/mpx:eGFPi114) fish displaying green neutrophils and red macrophages. (C) Quantification of neutrophils and macrophages in the intestinal area (n = 6-11 fish/group) (one way ANOVA Kruskal-Wallis test with Dunn's Multiple comparison Post-Test, mean ± SEM, ∗p < 0.05 ∗∗p < 0.01). Top: counted cells in intestinal area. Bottom: Corrected Total Cell Fluorescence (CTCF, measure for total fluorescent pixels in the whole fish). Two independent experiments were performed and data are combined. Figure 4: Effect of antibiotic exposure on saponin-immune-stimulation. (A) Percent survival of zebrafish exposed to control (E3), ciprofloxacin (4-9 dpf) (5 ug/L) or oxytetracycline (4-9 dpf) (5 ug/ml) + /- saponin (0.5 mg/ml) from 6-9 dpf (n = 100 fish / treatment) (Log-rank Mantel-Cox Test for Chi-square). (B) Representative pictures of the antibiotic/saponin-treated Tg(mpeg1:mCherry/mpx:eGFPi114) fish displaying green neutrophils and red macrophages. (C) Quantification of neutrophils and macrophages in the intestinal area (n = 10 fish/ group) (one way ANOVA Kruskal-Wallis test with Dunn's Multiple comparison Post-Test, mean ± SEM, ∗p < 0.05). Two independent experiments were performed and one representative experiment is shown. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.
Dynamic heterogeneity in complex interfaces of soft interface-dominated materials
Sagis, Leonard M.C. ; Liu, Bingxue ; Li, Yuan ; Essers, Jeffrey ; Yang, Jack ; Moghimikheirabadi, Ahmad ; Hinderink, Emma ; Berton-Carabin, Claire ; Schroen, Karin - \ 2019
Scientific Reports 9 (2019)1. - ISSN 2045-2322
Complex interfaces stabilized by proteins, polymers or nanoparticles, have a much richer dynamics than those stabilized by simple surfactants. By subjecting fluid-fluid interfaces to step extension-compression deformations, we show that in general these complex interfaces have dynamic heterogeneity in their relaxation response that is well described by a Kohlrausch-Williams-Watts function, with stretch exponent β between 0.4–0.6 for extension, and 0.6–1.0 for compression. The difference in β between expansion and compression points to an asymmetry in the dynamics. Using atomic force microscopy and simulations we prove that the dynamic heterogeneity is intimately related to interfacial structural heterogeneity and show that the dominant mode for stretched exponential relaxation is momentum transfer between bulk and interface, a mechanism which has so far largely been ignored in experimental surface rheology. We describe how its rate constant can be determined using molecular dynamics simulations. These interfaces clearly behave like disordered viscoelastic solids and need to be described substantially different from the 2d homogeneous viscoelastic fluids typically formed by simple surfactants.
Publisher Correction to : Background invertebrate herbivory on dwarf birch (Betula glandulosa-nana complex) increases with temperature and precipitation across the tundra biome
Barrio, Isabel C. ; Lindén, Elin ; Beest, Mariska Te; Olofsson, Johan ; Rocha, Adrian ; Soininen, Eeva M. ; Alatalo, Juha M. ; Andersson, Tommi ; Asmus, Ashley ; Boike, Julia ; Bråthen, Kari Anne ; Bryant, John P. ; Buchwal, Agata ; Bueno, C.G. ; Christie, Katherine S. ; Egelkraut, Dagmar ; Ehrich, Dorothee ; Fishback, Lee Ann ; Forbes, Bruce C. ; Gartzia, Maite ; Grogan, Paul ; Hallinger, Martin ; Heijmans, Monique M.P.D. ; Hik, David S. ; Hofgaard, Annika ; Holmgren, Milena ; Høye, Toke T. ; Huebner, Diane C. ; Jónsdóttir, Ingibjörg Svala ; Kaarlejärvi, Elina ; Kumpula, Timo ; Lange, Cynthia Y.M.J.G. ; Lange, Jelena ; Lévesque, Esther ; Limpens, Juul ; Macias-Fauria, Marc ; Myers-Smith, Isla ; Nieukerken, Erik J. van; Normand, Signe ; Post, Eric S. ; Schmidt, Niels Martin ; Sitters, Judith ; Skoracka, Anna ; Sokolov, Alexander ; Sokolova, Natalya ; Speed, James D.M. ; Street, Lorna E. ; Sundqvist, Maja K. ; Suominen, Otso ; Tananaev, Nikita ; Tremblay, Jean Pierre ; Urbanowicz, Christine ; Uvarov, Sergey A. ; Watts, David ; Wilmking, Martin ; Wookey, Philip A. ; Zimmermann, Heike H. ; Zverev, Vitali ; Kozlov, Mikhail V. - \ 2018
Polar Biology 41 (2018)8. - ISSN 0722-4060 - p. 1653 - 1654.
The above mentioned article was originally scheduled for publication in the special issue on Ecology of Tundra Arthropods with guest editors Toke T. Høye . Lauren E. Culler. Erroneously, the article was published in Polar Biology, Volume 40, Issue 11, November, 2017. The publisher sincerely apologizes to the guest editors and the authors for the inconvenience caused.
Letter: Climate law: path paved for civil action
Si, Y. ; Prins, H.H.T. - \ 2015
Nature 523 (2015)7561. - ISSN 0028-0836 - p. 410 - 410.
The Lancet Commission on Health and Climate Change last month concluded that climate change is a risk to public health (N. Watts et al. Lancet http://doi.org/56b; 2015). In the same week, a Dutch court ordered the government of the Netherlands to improve its reduction of greenhouse-gas emissions to protect the population from harm and to keep the country habitable by safeguarding the environment (see Nature http://doi.org/559; 2015). We suggest that this court order is closely studied by other countries. If governments do not act, they should expect lawsuits from families who lost relatives during, say, the heatwaves in Europe in 2003 or in Pakistan and India this year.
Community gardens in urban areas: a critical reflection on the extent to which they strenghten social cohesion and provide alternative food
Veen, E.J. - \ 2015
Wageningen University. Promotor(en): Han Wiskerke, co-promotor(en): Andries Visser; Bettina Bock. - Wageningen : Wageningen University - ISBN 9789462573383 - 265
publieke tuinen - tuinieren - stedelijke gebieden - bewonersparticipatie - buurtactie - stadslandbouw - alternatieve landbouw - volkstuinen - voedingsmiddelen - biologische voedingsmiddelen - sociologie - public gardens - gardening - urban areas - community participation - community action - urban agriculture - alternative farming - allotment gardens - foods - organic foods - sociology
The aims of this thesis are twofold; firstly, it aims to increase the understanding of the extent to which community gardens enhance social cohesion for those involved; secondly, it aims to gain insight into the importance community gardeners attach to food growing per se, and the extent to which participants perceive community gardens as an alternative to the industrial food system.
I define community gardens as a plot of land in an urban area, cultivated either communally or individually by people from the direct neighbourhood or the wider city, or in which urbanites are involved in other ways than gardening, and to which there is a collective element. Over the last years, community gardens have sprung up in several Dutch cities. Although there are various reasons for an increasing interest in community gardens, there are two that I focus on in this thesis in particular. The first is the assumption made that community gardens stimulate social cohesion in inner-city neighbourhoods, to be seen in the light of the ‘participatory society’. The second is community gardens’ contribution to the availability of locally produced food, in the context of an increased interest in Alternative Food Networks (AFNs).
The Dutch government aims to transform the Dutch welfare state into a participatory society in which citizens take more responsibility for their social and physical environment. This way the government not only hopes to limit public spending, but also wishes to increase social bonding and the self-organisational capacity of society. Community gardens fit the rhetoric around the participatory society, as they are examples of organised residents taking responsibility for their living environment. Moreover, the literature suggests that gardens are physical interventions that may decrease isolation by acting as meeting places. However, both the extent to which community gardens enhance social cohesion and under what conditions they may do so are unclear, especially as gardens come in various designs, shapes and sizes.
The popularity of community gardens also seems to be related to an overall increasing societal interest in food, and can be discussed in relation to Alternative Food Networks. AFNs are food systems that are different in some way from the mainstream, and are seen as a reaction to consumer concerns about the conventional food system. They are often considered to be dictated by political motivations and injected with a ‘deeper morality’. The category ‘AFN’ is however a heterogeneous category, as is the conventional food system; neither can be easily defined. The degree to which community gardens can be seen as AFNs is therefore unclear. While they do improve the availability of local food and operate outside of the market economy, we do not know how much and how often people eat from their gardens, nor do we know to what extent they are involved in the gardens in order to provide an alternative to the industrial food system. Hence, there is a lack of knowledge about the sense in which community gardens are alternative alternatives.
The overall research question of this thesis is:
What is the significance of community gardening in terms of its intention to promote social cohesion as well as its representation as an alternative food system?
This broad question is instructed by the following sub-questions:Why do people get involved in community gardens? What are their motivations?How, to what extent, and under which conditions does community gardening promote the development of social relations between participants? How do participants value these social effects? To what extent do the diets of community garden participants originate from the gardens in which they are involved? What is the importance of food in community gardens?What is the importance of growing or getting access to alternative food for participants of community gardens? Methodology
An important theoretical lens in this research is the theory of practice. Practices are defined as concrete human activity and include things, bodily doings and sayings. By performing practices people not only draw upon but also feed into structure. Routinisation – of practices, but also of daily life – therefore plays a central role in practice theory. Practice theory allows for an emphasis on practical reality as well as a study of motivations. This focus on how people manage everyday life, and how gardening fits within that, makes it particularly useful for this thesis.
I define social cohesion as the way in which people in a society feel and are connected to each other (De Kam and Needham 2003) and operationalised it by focusing on ‘social contacts, social networks, and social capital’, one of the elements into which social cohesion is often broken up. This element was operationalised as 1) contacts (the width of social cohesion) and 2) mutual help (the depth of social cohesion).
This research has a case study design; I studied four Dutch community gardens over a two-year period of time, and later supplemented these with an additional three cases. As practices consist of both doings and sayings, analysis must be concerned with both practical activity and its representation. I used participant observations to study practical activities, and interviews, questionnaires and document study to examine the representation of these activities.
Chapters 3 to 7 form the main part of this thesis. They are papers/book chapters that have been submitted to or are published by scientific journals or books. All of them are based on the field work.
In chapter 3 we compare two of the case studies and determine to what extent they can be seen as ‘alternative’. We argue that although reflexive motivations are present, most participants are unwilling to frame their involvement as political, and mundane motivations play an important role in people’s involvement as well. By using the concept of ‘food provisioning practices’ we show that participants of community gardens are often required to be actively involved in the production of their food. This means that participants are both producers and consumers: the gardens show a ‘sliding scale of producership’. This chapter also shows that political statements are not a perfect predictor of actual involvement in community gardening. This finding was one of the main reasons for starting to use the theory of practice, which is the main topic of the next chapter.
In chapter 4 we compare one of my case studies with an urban food growing initiative in New York City. By comparing the internal dynamics of these two cases and their relations with other social practices, we investigate whether different urban food growing initiatives can be seen as variations of one single practice. We also study the question of whether the practice can be seen as emerging. In particular, we take the elements of meaning, competences and material (Shove et al. 2012) into account. We found both similarities and differences between the two cases, with the main difference relating to the meanings practitioners attach to the practice. We conclude, therefore, that it is not fully convincing to see these cases as examples of the same social practice. We also argue that urban food growing may be considered an emerging practice, because it combines various practices, both new and established, under one single heading.
In chapter 5 we use the theory of practice to explore how urban food growing is interwoven with everyday life. We compare four community gardens - two allotments and two cases which we define as AFNs. We found that participants of the allotments are involved in the practice of gardening, while members of the AFNs are involved in the practice of shopping. The gardening practice requires structural engagement, turning it into a routine. The produce is a result of that routine and is easily integrated into daily meals. As AFNs are associated with the practice of shopping, they remain in competition with more convenient food acquisition venues. Eating from these gardens is therefore less easily integrated in daily life; every visit to the garden requires a conscious decision. Hence, whether members are primarily involved in shopping or in growing has an impact on the degree to which they eat urban-grown food. This shows that motivations are embedded in the context and routine of everyday life, and ‘only go so far’.
Chapter 6 concerns the organisational differences between the seven case studies in this thesis and the extent to which these influence the enhancement of social cohesion. We study people’s motivations for being involved in the gardens and compare these with the three main organisational differences. This comparison reveals that the gardens can be divided into place-based and interest-based gardens. Place-based gardens are those in which people participate for social reasons – aiming to create social bonds in the neighbourhood. Interest-based gardens are those in which people participate because they enjoy growing vegetables. Nevertheless, all of these gardens contribute to the development of social cohesion. Moreover, while participants who are motivated by the social aspects of gardening show a higher level of appreciation for them, these social aspects also bring added value for those participants who are motivated primarily by growing vegetables.
In chapter 7 we present a garden that exemplifies that gardens may encompass not only one, but indeed several communities, and that rapprochement and separation take place simultaneously. While this garden is an important meeting place, thereby contributing to social cohesion, it harbours two distinct communities. These communities assign others to categories (‘us’ and ‘them’) on the basis of place of residence, thereby strengthening their own social identities. Ownership over the garden is both an outcome and a tool in that struggle. We define the relationship between these two communities as instrumental-rational – referring to roles rather than individuals - which explains why they do not form a larger unity. Nevertheless, the two communities show the potential to develop into a larger imagined garden-community.
This thesis shows that the different organisational set-ups of community gardens reflect gardeners’ different motivations for being involved in these gardens. The gardens studied in this thesis can be defined as either place-based or interest-based; gardens in the first category are focused on the social benefits of gardening, whereas gardens in the second category are focused on gardening and vegetables. Nevertheless, social effects occur in both types of gardens; in all of the gardens studied, participants meet and get to know others and value these contacts. Based on this finding, I conclude that community gardens do indeed enhance social cohesion.
Place-based community gardens specifically have the potential to become important meeting places; they offer the opportunity to work communally towards a common goal, and once established, can develop into neighbourhood spaces to be used for various other shared activities. Most interest-based gardens lack opportunities to develop the social contacts that originated at the garden beyond the borders of the garden. These gardens are often maintained by people who do not live close to the garden or to each other, and those who garden are generally less motivated by social motivations per se. Important to note is that community gardens do not necessarily foster a more inclusive society; they often attract people with relatively similar socio-economic backgrounds and may support not one, but several communities.Most participants from place-based gardens eat from their gardens only occasionally; others never do so. This type of community garden can therefore hardly be seen as a reaction to the industrialised food system, let alone an attempt to create an alternative food system. Nevertheless, certain aspects of these gardens are in line with the alternative rhetoric. By contrast, most gardeners at interest-based gardens eat a substantial amount of food from their gardens, and to some of them the choice to consume this locally-grown food relates to a lifestyle in which environmental considerations play a role. However, this reflexivity is not expressed in political terms and participants do not see themselves as part of a food movement. Participants who buy rather than grow produce showed the greatest tendency to explain their involvement in political terms, but many of them have difficulty including the produce in their diets on a regular basis. I therefore conclude that community gardens cannot be seen as conscious, ‘alternative’ alternatives to the industrial food system. Nonetheless, the role of food in these gardens is essential, as it is what brings participants together – either because they enjoy gardening or because the activities which are organised there centre around food.
In this thesis I used and aimed to contribute to the theory of practice. Using participant observations to study what people do in reality was particularly useful. It turned research into an embodied activity, enabling me to truly ‘live the practice’, and therefore to understand it from the inside.
Deconstructing the practice of food provisioning into activities such as buying, growing and cooking was helpful in gaining an understanding of how people manage everyday life, and how food acquisitioning fits into their everyday rhythms. It sheds light on how and to what extent people experience the practice of community gardening as a food acquisitioning practice, and to what degree they relate it to other elements of food provisioning such as cooking and eating. The focus on the separate elements of food provisioning practices helped me realise that acquiring food from community gardens represents a different practice to different people; some are engaged in the practice of growing food, others in the practice of shopping for food.
This thesis showed that motivations delineate how the practice ‘works out in practice’; the way in which a practice such as community gardening is given shape attracts people with certain motivations, who, by reproducing that practice, increase the attractiveness of the practice for others with similar motivations. This implies that while community gardening appears to be one practice, it should in fact be interpreted as several distinct practices, such as the practice of food growing or the practice of social gathering. Motivations therefore influence a garden’s benefits and outcomes. This thesis thus highlights that motivations should not be overlooked when studying practices.
Apprehending the motivations of community gardeners is also an important contribution to the literature around AFNs, since it helps us to understand the extent to which urban food production is truly alternative. By studying motivations, this thesis reveals that AFNs do not necessarily represent a deeper morality, or that not all food growing initiatives in the city can be defined as alternative. However, participants of community gardens are often both producers and consumers (there is a ‘sliding scale of producership’); the gardens are thus largely independent from the conventional food system. Moreover, for participants who buy produce, the meaning of the gardens often goes beyond an economic logic (there is a ‘sliding scale of marketness’). Hence, while the gardens studied in this thesis are no alternative alternatives, most of them can be qualified as ‘actually existing alternatives’ (after Jehlicka and Smith 2011).
This thesis showed that even those gardens in which the commodification of food is being challenged do not necessarily represent a deeper morality, which is contrary to what is argued by Watts et al. (2005). This implies that understanding whether or not initiatives resist incorporation into the food system is insufficient to be able to determine whether or not they can be defined as alternative food networks. However, determining whether or not deeper moral reflection is present is not a satisfactory way of defining food networks as alternative either, as this neglects the fact that motivations do not always overlap with practical reality. This suggests that establishing whether a food network can be regarded as alternative requires studying both motivations and practical reality. The thesis also raises the question to what extent the label AFN is still useful. Since it is unclear what ‘alternative’ means exactly, it is also unclear whether a given initiative can be considered alternative. Moreover, the world of food seems too complex to be represented by a dichotomy between alternative and conventional food systems; the gardens presented in this thesis are diverse and carry characteristics of both systems. I therefore suggest considering replacing the term AFN with that of civic food networks, as Renting et al. (2012) advocate.
Evaluation of two commercial, rapid, ELISA kits testing or scrapie in retro-pharyngeal lymph nodes in sheep
Kittelberger, R. ; McIntuyre, L. ; Watts, S. ; MacDiarmid, S. ; Hannah, M.J. ; Jenner, J. ; Bueno, R. ; Swainsbury, R. ; Langeveld, J.P.M. ; Keulen, L.J.M. van; Zijderveld, F.G. van; Wemheuer, W.M. ; Richt, J.A. ; Sorenson, S.J. ; Pigott, C.J. ; O'Keefe, J.S. - \ 2014
New Zealand Veterinary Journal 62 (2014)6. - ISSN 0048-0169 - p. 343 - 350.
natural scrapie - prion protein - immunohistochemical detection - new-zealand - prp - accumulation - diagnosis - genotypes - tissues - brain
AIMS: To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN) from non-infected and infected sheep of different PrP genotypes. METHODS: Using published data on the distribution of PrP genotypes within the New Zealand sheep flock and the prevalence of cases of scrapie in these genotypes in the United Kingdom, the annual expected number of cases of scrapie per genotype was estimated, should scrapie become established in New Zealand, assuming a total population of 28 million sheep. A non-infected panel of RLN was collected from 737 sheep from New Zealand that had been culled, found in extremis or died. Brain stem samples were also collected from 131 of these sheep. A second panel of infected samples comprised 218 and 117 RLN from confirmed scrapie cases that had originated in Europe and the United States of America, respectively. All samples were screened using two commercial, rapid, transmissible spongiform encephalopathy ELISA kits: Bio-Rad TeSeE ELISA (ELISA-BR), and IDEXX HerdChek BSE-Scrapie AG Test (ELISA-ID). RESULTS: If scrapie became established in New Zealand, an estimated 596 cases would occur per year; of these 234 (39%) and 271 (46%) would be in sheep carrying ARQ/ARQ and ARQ/VRQ PrP genotypes, respectively. For the non-infected samples from New Zealand the diagnostic specificity of both ELISA kits was 100%. When considering all infected samples, the diagnostic sensitivity was 70.4 (95% CI=65.3-75.3)% for ELISA-BR and 91.6 (95% CI=88.2-94.4)% for ELISA-ID. For the ARQ/ARQ genotype (n=195), sensitivity was 66.2% for ELISA-BR and 90.8% for ELISA-ID, and for the ARQ/VRQ genotype (n=107), sensitivity was 81.3% for ELISA-BR and 98.1% for ELISA-ID. CONCLUSIONS: In this study, the ELISA-ID kit demonstrated a higher diagnostic sensitivity for detecting scrapie in samples of RLN from sheep carrying scrapie-susceptible PrP genotypes than the ELISA-BR kit at comparable diagnostic specificity.
Sex-biased inbreeding effects on reproductive success and home range size of the critically endangered black rhinoceros
Cain, W.S. ; Wandera, A.B. ; Shawcross, S.G. ; Ouma, B.O. ; Watts, P.C. - \ 2014
Conservation Biology 28 (2014)2. - ISSN 0888-8892 - p. 594 - 603.
heterozygosity-fitness correlations - wide genetic diversity - natural-populations - diceros-bicornis - multilocus heterozygosity - microsatellite markers - wild populations - south-africa - depression - reserve
A central premise of conservation biology is that small populations suffer reduced viability through loss of genetic diversity and inbreeding. However, there is little evidence that variation in inbreeding impacts individual reproductive success within remnant populations of threatened taxa, largely due to problems associated with obtaining comprehensive pedigree information to estimate inbreeding. In the critically endangered black rhinoceros, a species that experienced severe demographic reductions, we used model selection to identify factors associated with variation in reproductive success (number of offspring). Factors examined as predictors of reproductive success were age, home range size, number of nearby mates, reserve location, and multilocus heterozygosity (a proxy for inbreeding). Multilocus heterozygosity predicted male reproductive success (p<0.001, explained deviance >58%) and correlated with male home range size (p <0.01, r2 > 44%). Such effects were not apparent in females, where reproductive success was determined by age (p <0.01, explained deviance 34%) as females raise calves alone and choose between, rather than compete for, mates. This first report of a 3-way association between an individual male's heterozygosity, reproductive output, and territory size in a large vertebrate is consistent with an asymmetry in the level of intrasexual competition and highlights the relevance of sex-biased inbreeding for the management of many conservation-priority species. Our results contrast with the idea that wild populations of threatened taxa may possess some inherent difference from most nonthreatened populations that necessitates the use of detailed pedigrees to study inbreeding effects. Despite substantial variance in male reproductive success, the increased fitness of more heterozygous males limits the loss of heterozygosity. Understanding how individual differences in genetic diversity mediate the outcome of intrasexual competition will be essential for effective management, particularly in enclosed populations, where individuals have restricted choice about home range location and where the reproductive impact of translocated animals will depend upon the background distribution in individual heterozygosity. © 2013 Society for Conservation Biology.
Estimating ET using scintillometers and satellites in an irrigated vineyard in the Costa De Hermosillo, Sonora, Mexico
Mulder, M. ; Lopez-Ibarra, J.A. ; Watts, C.J. ; Rodriquez, J.C. ; Hartogensis, O.K. ; Moene, A.F. - \ 2013
In: Proceedings of a symposium held at Jackson Hole. - - p. 195 - 198.
Observation techniques for surface energy balance
components on kilometer scale. Several methods have been proposed to estimate ET over
large areas which combine Earth Observation Satellite data
with standard climate data. Here we use the Makkink
approach where incoming solar radiation is obtained by
calculating exoatmospheric incoming solar radiation, using
visible data from GOES West to estimate cloudiness and
16-day composite MODIS Enhanced Vegetation Index data to
estimate fractional vegetation cover. This methodology can be
used operationally at a spatial resolution of 1 km2 but
validation data are required at a similar spatial scale. Large
Aperture Scintillometers transmit and receive near infrared
radiation over distances of several kilometers and provide
measurements of the structure parameter for the refractive
index of air which is related by Monin-Obukhov Similarity
Theory to the surface sensible heat flux (H), which requires
measurements of air temperature, pressure and wind speed.
ET can then be obtained indirectly as the residual of the
energy balance, ET = Rn – G – H so that we need estimates of
Net Radiation (Rn) and Soil Heat Flux (G) as well. A
scintillometer (Scintec BLS-450) was installed over an
irrigated vineyard with area of 72 hectares (1200m x 600m) in
June 6th 2009. Net Radiation was measured in the field and
soil heat flux was estimated using G = A * Rn, where the
parameter A was obtained from 8-day composite MODIS Land
Surface Temperature data. Comparison of ET derived from
satellite and scintillometer for June 2009 showed considerable
scatter with r2 = 0.81 and ETSAT = 1.12 * ETBLS. This
apparent overestimation from the satellite-based ET is similar
to that found in previous work. However, in these initial
calculations it was assumed that unstable conditions would
prevail during the daytime but it appears that stable
conditions often occur in the late afternoon. Secondly, the
estimation of G needs to be carefully revised since this can
have a large effect on ET. These factors are being included in
the analysis of data over an entire growing season to assess
the seasonal behavior of the model.
Mechanism-Based Covalent Neuraminidase Inhibitors with Broad Spectrum Influenza Antiviral Activity
Kim, J.H. ; Resende, R. ; Wennekes, T. ; Chen, N. ; Bance, N. ; Buchini, S. ; Watts, A.G. ; Pilling, P. ; Streltsov, V.A. ; Petric, M. ; Liggins, R. ; Barrett, S. ; McKimm-Breschkin, J.L. ; Niikura, M. ; Withers, S.G. - \ 2013
Science 340 (2013)6128. - ISSN 0036-8075 - p. 71 - 75.
virus neuraminidase - drug design - h1n1 virus - resistant - sialidase - 4-guanidino-neu5ac2en - sensitivity - oseltamivir - mutations - variant
Influenza antiviral agents play important roles in modulating disease severity and in controlling pandemics while vaccines are prepared, but the development of resistance to agents like the commonly used neuraminidase inhibitor oseltamivir may limit their future utility. We report here a new class of specific, mechanism-based anti-influenza drugs that function via the formation of a stabilized covalent intermediate in the influenza neuraminidase enzyme, and confirm this mode of action via structural and mechanistic studies. These compounds function in cell-based assays and in animal models, with efficacies comparable to that of the neuraminidase inhibitor zanamivir and with broad spectrum activity against drug-resistant strains in vitro. The similarity of their structure to that of the natural substrate and their mechanism-based design make these attractive antiviral candidates
Motivations, Refexivity and Food Provisioning in Alternative Food Networks: Case Studies in Two Medium-sized Towns in The Netherlands
Veen, E.J. ; Derkzen, P.H.M. ; Wiskerke, J.S.C. - \ 2012
International Journal of Sociology of Agriculture and Food 19 (2012)3. - ISSN 0798-1759 - p. 365 - 382.
Grow your own is emerging as a trendy urban activity. Becoming involved in ‘farming’ inside the city is framed in the media, on the Internet and in policy discourse as an emergent food movement. In this article we look at food provisioning practices inside cities and situate these in the literature on alternative food networks, responding to two of Treager’s main critiques. We use the concept of ‘food provisioning practices’ to overcome the critique of producer–consumer dichotomy since the concept treats people holistically as people undertaking activities. Rather than assuming that involvement in AFNs does or should represent a radical political act for any of its participants, we disentangle the multiple beliefs and motivations – including the most mundane – of the actors involved in two cases. We find that, because people are required to be actively involved in the production of their food, participants of both cases are neither only producers nor only consumers; they are both. The gardens show a ‘sliding scale of producership’. Our research also shows that, although reflexive motivations are present, many participants are unwilling to frame their involvement as political, nor do all participants see themselves as part of a movement. Hence, although personal choices may become political, we have to be careful not to ascribe attributes to participants that they themselves do not formulate. Moreover, we found that mundane motivations are important as well, and that political articulations do not predict actual involvement perfectly. This means therefore, unlike what Watts et al. argue, that reflexivity is not necessarily connected to the strength of the network.
Evolution of blind beetles in isolated aquifers: a test of alternative modes of speciation
Leys, R. ; Nes, E.H. van; Watts, C.H. ; Cooper, S.J.B. ; Humphreys, W.F. ; Hogendoorn, K. - \ 2012
PLoS ONE 7 (2012)3. - ISSN 1932-6203 - 8 p.
subterranean diving beetles - mitochondrial-dna phylogeography - size-structured populations - sympatric speciation - western-australia - adaptive radiation - ecological speciation - mathematical-models - oceanic island - yilgarn region
Evidence is growing that not only allopatric but also sympatric speciation can be important in the evolution of species. Sympatric speciation has most convincingly been demonstrated in laboratory experiments with bacteria, but field-based evidence is limited to a few cases. The recently discovered plethora of subterranean diving beetle species in isolated aquifers in the arid interior of Australia offers a unique opportunity to evaluate alternative modes of speciation. This naturally replicated evolutionary experiment started 10-5 million years ago, when climate change forced the surface species to occupy geographically isolated subterranean aquifers. Using phylogenetic analysis, we determine the frequency of aquifers containing closely related sister species. By comparing observed frequencies with predictions from different statistical models, we show that it is very unlikely that the high number of sympatrically occurring sister species can be explained by a combination of allopatric evolution and repeated colonisations alone. Thus, diversification has occurred within the aquifers and likely involved sympatric, parapatric and/or microallopatric speciation
Interfacial Properties of an Ionic Liquid by Molecular Dynamics
Heggen, B. ; Zhao, W. ; Leroy, F. ; Dammers, A.T. ; Müller-Plathe, F. - \ 2010
The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical 114 (2010)20. - ISSN 1520-6106 - p. 6954 - 6961.
nuclear magnetic-relaxation - 1-butyl-3-methylimidazolium hexafluorophosphate - surface-tension - physicochemical properties - force-field - temperature - simulation - imidazolium - package
We studied the influence of a liquid-vapor interface on dynamic properties like reorientation and diffusion as well as the surface tension of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) by molecular dynamics simulations. In the interfacial region, reorientation of a short molecular axis is slightly faster than that in the central layer, while that of the longer molecular axis is retarded. The molecular reorientation is well-described by a stretched exponential decay modeled by the Kohlrausch-Williams-Watts equation. Analysis of the average translational diffusion coefficient of molecules in a central layer shows consistency with the Vogel-Fulcher-Tamann equation in a temperature range from 300 to 380 K. A first-passage time analysis of the system at 380 K yields a more refined spatial characterization of translational diffusion perpendicular to the liquid-vapor interfaces. In the central region of the slab, the diffusion coefficient of cations is only marginally higher than that of anions, but close to an interface, this difference is much higher, up to 50%. Apparent activation energies for rotational and diffusional dynamics, respectively, were estimated assuming Arrhenius behavior. They indicate that reorientation of the long molecular axis depends on the diffusion ability, whereas for the reorientation of the short axis, no such correlation is observed. The results are in general agreement with the literature, with slightly overestimated absolute values. This applies as well for the surface tension, where, however, a dependence on the treatment of the electrostatics was found. Particle-mesh Ewald (PME) or reaction field (RF) and the treatment of bonds by constraints have an influence. If no bond constraints are applied, the results are consistent for both methods for the description of the electrostatics.
MOST relationships for the structure parameter of temperature under very unstable conditions
Bruin, H.A.R. de; Watts, C.J. ; Gratuza-Payan, J. ; Rodriguez, J. ; Hartogensis, O.K. - \ 2008
In: EMS Annual Meeting Abstracts, Eighth Annual Meeting of the European Meteorological Society, Amsterdam, 29 September-3 October 2008. - EMS - p. A - 00211.
MATADOR 2002: A pilot field experiment on convective plumes and dust devils
Renno, N.O. ; Abreu, V.J. ; Koch, J. ; Smith, P.H. ; Hartogensis, O.K. ; Debruin, H.A.R. ; Burose, D. ; Delory, G.T. ; Farrell, W.M. ; Watts, C.J. ; Garatuza, J. ; Parker, M. ; Carswell, A. - \ 2004
Journal of Geophysical Research: Planets 109 (2004). - ISSN 2169-9097 - p. E07001 - E07001.
mars orbiter camera - pathfinder - vortices - aircraft - surface - storms - layer
Recent research suggests that mineral dust plays an important role in terrestrial weather and climate, not only by altering the atmospheric radiation budget, but also by affecting cloud microphysics and optical properties. In addition, dust transport and related Aeolian processes have been substantially modifying the surface of Mars. Dusty convective plumes and dust devils are frequently observed in terrestrial deserts and are ubiquitous features of the Martian landscape. There is evidence that they are important sources of atmospheric dust on both planets. Many studies have shown that on a small scale, dust sourcing is sensitive to a large number of factors, such as soil cover, physical characteristics, composition, topography, and weather. We have been doing comparative studies of dust events on Earth and Mars in order to shed light on important physical processes of the weather and climate of both planets. Our 2002 field campaign showed that terrestrial dust devils produce heat and dust fluxes two and five orders of magnitude larger than their background values. It also showed that charge separation within terrestrial dust devils produces strong electric fields that might play a significant role in dust sourcing. Since Martian dust devils and dust storms are stronger and larger than terrestrial events, they probably produce even stronger fluxes and electric fields.