Modelling populations of long-lived birds of prey for conservation: A study of imperial eagles (Aquila heliaca) in Kazakhstan     

Todd E. Katzner  Evgeny A. Bragin 《Biological conservation》2006,132(3):322-335

Eagle populations worldwide are in decline and their demography is generally poorly understood. We use novel sensitivity analysis of stochastic simulation models to analyse the demography of the worlds highest-density and longest-studied population of eastern imperial eagles (Aquila heliaca), at the Naurzum National Nature Reserve in Kazakhstan. Single variable perturbation (a simple elasticity-type analysis) showed that population growth was most sensitive to changes in adult survival but provided no information on how interactions between parameters may influence population growth. Multiple-variable perturbations (a more comprehensive elasticity-type analysis) suggested that population growth is relatively more sensitive to adult survival than is indicated by single-variable perturbation but also that when adult survival is within a biologically reasonable range, other parameters are still highly consequential to model outputs. For Naurzum’s imperial eagles, and for other structured populations of vertebrates, effective conservation and management likely requires an approach that addresses the importance of simultaneous variation in multiple vital rates including both survivorship and reproductive output.  相似文献   

H2S: a universal defense against antibiotics in bacteria   总被引：1，自引：0，他引：1  

Shatalin K  Shatalina E  Mironov A  Nudler E 《Science (New York, N.Y.)》2011,334(6058):986-990

Many prokaryotic species generate hydrogen sulfide (H(2)S) in their natural environments. However, the biochemistry and physiological role of this gas in nonsulfur bacteria remain largely unknown. Here we demonstrate that inactivation of putative cystathionine β-synthase, cystathionine γ-lyase, or 3-mercaptopyruvate sulfurtransferase in Bacillus anthracis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli suppresses H(2)S production, rendering these pathogens highly sensitive to a multitude of antibiotics. Exogenous H(2)S suppresses this effect. Moreover, in bacteria that normally produce H(2)S and nitric oxide, these two gases act synergistically to sustain growth. The mechanism of gas-mediated antibiotic resistance relies on mitigation of oxidative stress imposed by antibiotics.  相似文献   

Parallel late ontogeny transformations in contrasting landlocked phenotypes of Salvelinus malma (Salmonidae) from small volcanic lakes     

Evgeny V. Esin  Grigorii N. Markevich 《Ecology of Freshwater Fish》2019,28(4):624-638

A rapid phenotype deviation is a common population response to atypical environmental conditions in aquatic animals. However, the implications for adaptive specialisation, stochastic segregation and ancestral traits fixation in the stress‐induced phenotype transformation are not clear. Here, we cross‐analyse the populations of commonly fluvial Dolly Varden charr Salvelinus malma multiply locked in small lakes (<1 km²) throughout Kamchatkan volcanic range to assess the ratio of (non)parallel outcomes of phenotype specialisation under stress conditions. The growth rate and definitive size parameters show a twofold difference in six populations inhabiting the same resource‐poor lakes. An inter‐population comparison revealed a weakly pronounced morphological similarity—no directional vector towards lacustrine lifestyle is detected in body and skull shape. Local morphotypes experiencing random segregation and ancestral fixation processes inherit the unique morphometric, meristic and cranial characteristics. The most ancient populations are characterised by the most paedomorphic exterior and archaic anatomical peculiarities. Parallelism in population structure manifests itself in growth acceleration of some mature or maturing individuals resulting in two distinct size groups with different allometric body proportions. Small fish (50–260 g, average age 6–7 years) feed on invertebrates throughout their life, while the biggest ones (290–780 g, average age 8 years) switch to cannibalism. This transformation does not lead to any inherited sympatric polymorphism. Thus, we did not reveal any common vector of the stress‐induced specialisation; adaptive phenotypes are strongly influenced by the resource dynamics.  相似文献   

Irreversible sorption of humic substances causes a decrease in wettability of clay surfaces as measured by a sessile drop contact angle method     

Vladimir A. Kholodov  Evgeny Y. Milanovskiy  Andrey I. Konstantinov  Zemfira N. Tyugai  Nadezhda V. Yaroslavtseva  Irina V. Perminova 《Journal of Soils and Sediments》2018,18(4):1327-1334

  相似文献   

Structural features of tundra and taiga soil humic acids according to IR EXPERT analytical system data     

Tikhova  Vera D.  Deryabina  Yuliya M.  Vasilevich  Roman S.  Lodygin  Evgeny D. 《Journal of Soils and Sediments》2019,19(6):2697-2707

Journal of Soils and Sediments - The purpose of this work is to identify the most probable structural fragments of the tundra and the taiga soil humic acids on the basis of computer analysis of...  相似文献   

Influence of Pesticides on UDP-glucuronosyltransferase in Rat Liver Microsomes     

Zlatina Naydenova  Zoltan Urshev  Evgeny Golovinsky  Konstantin Grancharov 《Pest management science》1996,47(1):25-30

Fifteen pesticides, representatives of different chemical groups, were tested for their inhibitory effect on the glucuronidation of 4-nitrophenol (4-NP) and phenolphthalein (PPh) by rat liver microsomes. Three herbicides (simazine, chlorsulfuron, tribenuron-methyl), two insecticides (dioxacarb, carbaryl) and one fungicide (zineb) significantly decreased the UDP-glucuronosyltransferase (UDPGT) activity. The carbamate insecticide dioxacarb was found to be the most potent inhibitor, at 1 mM concentration suppressing 4-NP-UDPGT activity completely, and reducing by 55% the activity associated with the conjugation of PPh. One millimole simazine and carbaryl affected only 4-NP glucuronidation, while chlorsulfuron and zineb exerted a marked inhibition of both 4-NP and PPh conversion. Concentrations of 0·1 mM carbaryl, dioxacarb and zineb were still inhibitory against 4-NP-UDPGT, with zineb producing 40% inhibition of PPh glucuronidation. As a whole, UDPGT isoforms conjugating PPh were less sensitive to the agrochemicals tested. Kinetic studies with dioxacarb, chlorsulfuron and carbaryl revealed a mixed type of inhibition with respect to the acceptor substrate 4-NP, with apparentK_i values of 70 μM , 120 μM and 160 μM , respectively.  相似文献   

Interannual variability in the abundance and composition of spring larval fish assemblages in the Strait of Georgia (British Columbia,Canada) from 2007 to 2010          下载免费PDF全文

Lu Guan  John F. Dower  Skip M. McKinnell  Pierre Pepin  Evgeny A. Pakhomov  Brian P. V. Hunt 《Fisheries Oceanography》2017,26(6):638-654

Spring larval fish assemblages in the Strait of Georgia (British Columbia, Canada) were characterized for the first time based on three spatially extensive field surveys in late‐April of 2007, 2009 and 2010, a period which spanned both warm and cold environmental conditions. The abundance, diversity and community structure of the assemblages were examined to investigate interannual variability, and responses to environmental fluctuations. A total of 49 taxa from 23 families were identified. The dominant taxa were Clupea pallasi, Gadus chalcogrammus, Merluccius productus, Leuroglossus schmidti, Lyopsetta exilis and Sebastes spp. Total larval abundance was much lower in 2009 (c. 32 per 1000 m³) than in 2007 and 2010 (c. 200 per 1000 m³). However, the mean size of individuals from several species was largest in 2009. Assemblage structure varied dramatically; from dominance by M. productus in 2007, to dominance by C. pallasi and G. chalcogrammus in 2009, followed by a shift to dominance by benthic species including Sebastes spp. and several flatfishes in 2010. Variability in assemblage structure among the three study years was primarily related to water temperature, whereas within‐year patterns were more closely associated with salinity and chlorophyll, both of which were affected by estuarine circulation. This study provides baseline information about the status of the larval fish community in the Strait of Georgia in recent years, and offers a better understanding of their short‐term dynamics and response to environmental fluctuations.  相似文献   

Marine Fungal Cerebroside Flavuside B Protects HaCaT Keratinocytes against Staphylococcus aureus Induced Damage     

Ekaterina A. Chingizova  Ekaterina S. Menchinskaya  Artur R. Chingizov  Evgeny A. Pislyagin  Elena V. Girich  Anton N. Yurchenko  Irina V. Guzhova  Valery V. Mikhailov  Dmitry L. Aminin  Ekaterina A. Yurchenko 《Marine drugs》2021,19(10)

Cerebrosides are glycosylated sphingolipids, and in mammals they contribute to the pro-/anti-inflammatory properties and innate antimicrobial activity of the skin and mucosal surfaces. Staphylococcus aureus infection can develop, not only from minor scratches of the skin, but this pathogen can also actively promote epithelial breach. The effect of cerebroside flavuside B from marine sediment-derived fungus Penicillium islandicum (Aniva Bay, the Sea of Okhotsk) on viability, apoptosis, total caspase activity, and cell cycle in human epidermal keratinocytes HaCaT line co-cultivated with S. aureus, as well as influence of flavuside B on LPS-treated HaCaT cells were studied. Influence of flavuside B on bacterial growth and biofilm formation of S. aureus and its effect on the enzymatic activity of sortase A was also investigated. It was found S. aureus co-cultivated with keratinocytes induces caspase-depended apoptosis and cell death, arrest cell cycle in the G0/G1 phase, and increases in cellular immune inflammation. Cerebroside flavuside B has demonstrated its antimicrobial and anti-inflammatory properties, substantially eliminating all the negative consequences caused by co-cultivation of keratinocytes with S. aureus or bacterial LPS. The dual action of flavuside B may be highly effective in the treatment of bacterial skin lesions and will be studied in the future in in vivo experiments.  相似文献   

Distribution patterns and population structure of the blue shark (Prionace glauca) in the Atlantic and Indian Oceans          下载免费PDF全文

Rui Coelho  Jaime Mejuto  Andrés Domingo  Kotaro Yokawa  Kwang‐Ming Liu  Enric Cortés  Evgeny V. Romanov  Charlene da Silva  Fábio Hazin  Freddy Arocha  Aldrin Masawbi Mwilima  Pascal Bach  Victoria Ortiz de Zárate  William Roche  Pedro G. Lino  Blanca García‐Cortés  Ana M. Ramos‐Cartelle  Rodrigo Forselledo  Federico Mas  Seiji Ohshimo  Dean Courtney  Philippe S. Sabarros  Bernardo Perez  Ciara Wogerbauer  Wen‐Pei Tsai  Felipe Carvalho  Miguel N. Santos 《Fish and Fisheries》2018,19(1):90-106

The blue shark (Prionace glauca) is the most frequently captured shark in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. As part of cooperative scientific efforts for fisheries and biological data collection, information from fishery observers, scientific projects and surveys, and from recreational fisheries from several nations in the Atlantic and Indian Oceans was compiled. Data sets included information on location, size and sex, in a total of 478,220 blue shark records collected between 1966 and 2014. Sizes ranged from 36 to 394 cm fork length. Considerable variability was observed in the size distribution by region and season in both oceans. Larger blue sharks tend to occur in equatorial and tropical regions, and smaller specimens in higher latitudes in temperate waters. Differences in sex ratios were also detected spatially and seasonally. Nursery areas in the Atlantic seem to occur in the temperate south‐east off South Africa and Namibia, in the south‐west off southern Brazil and Uruguay, and in the north‐east off the Iberian Peninsula and the Azores. Parturition may occur in the tropical north‐east off West Africa. In the Indian Ocean, nursery areas also seem to occur in temperate waters, especially in the south‐west Indian Ocean off South Africa, and in the south‐east off south‐western Australia. The distributional patterns presented in this study provide a better understanding of how blue sharks segregate by size and sex, spatially and temporally, and improve the scientific advice to help adopt more informed and efficient management and conservation measures for this cosmopolitan species.  相似文献   

Immunity-related genes and gene families in Anopheles gambiae   总被引：2，自引：0，他引：2  

Christophides GK  Zdobnov E  Barillas-Mury C  Birney E  Blandin S  Blass C  Brey PT  Collins FH  Danielli A  Dimopoulos G  Hetru C  Hoa NT  Hoffmann JA  Kanzok SM  Letunic I  Levashina EA  Loukeris TG  Lycett G  Meister S  Michel K  Moita LF  Müller HM  Osta MA  Paskewitz SM  Reichhart JM  Rzhetsky A  Troxler L  Vernick KD  Vlachou D  Volz J  von Mering C  Xu J  Zheng L  Bork P  Kafatos FC 《Science (New York, N.Y.)》2002,298(5591):159-165

We have identified 242 Anopheles gambiae genes from 18 gene families implicated in innate immunity and have detected marked diversification relative to Drosophila melanogaster. Immune-related gene families involved in recognition, signal modulation, and effector systems show a marked deficit of orthologs and excessive gene expansions, possibly reflecting selection pressures from different pathogens encountered in these insects' very different life-styles. In contrast, the multifunctional Toll signal transduction pathway is substantially conserved, presumably because of counterselection for developmental stability. Representative expression profiles confirm that sequence diversification is accompanied by specific responses to different immune challenges. Alternative RNA splicing may also contribute to expansion of the immune repertoire.  相似文献