Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.288
Filtrar
1.
J Zoo Wildl Med ; 53(4): 654-660, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640066

RESUMO

Cardiac troponin I (cTnI) is specific to myocardial tissue, highly conserved across taxa, and a reliable indicator of myocardial disease in human and veterinary medicine. Biomarkers, like cTnI, may be useful for cardiac evaluation of elephants because the application of other modalities is complicated by the size of the animal. The goal of this study was to establish observed ranges for plasma cTnI in Asian elephants (Elephas maximus) measured by two point-of-care analyzers. Blood was collected from captive juvenile (≤15 yr; n = 9), adult (16-50 yr; n = 42), and geriatric (>50 yr; n = 16) elephants. Following centrifugation, heparinized plasma was stored at 5°C prior to and in between analyses on iSTAT (Abbott Point of Care Inc, Princeton, NJ 08540, USA) and HUBI-QUANpro (Humiasis Co, Ltd, Anyang-si 14042, South Korea) analyzers. With the exception of two results, plasma concentrations of cTnI were below the limit of quantification (LOQ < 0.05 ng/ml) for the HUBI-QUANpro (n = 64), which prohibited comparison between the two analyzers. Observed ranges were determined for plasma cTnI concentrations reported by the iSTAT for the entire population sampled (n = 58; mean 0.011 ng/ml; SD ± 0.013 ng/ml; range 0.00-0.07 ng/ml; 95% CI 0.008-0.015 ng/ml; median 0.01 ng/ml) and with outliers excluded (n = 50; mean 0.007 ng/ml; SD ± 0.007 ng/ml; range 0.00-0.02 ng/ml; 95% CI 0.005-0.009 ng/ml; median 0.01 ng/ml). No significant differences were observed between age classes (P = 0.70) or sexes (P = 0.34). Higher cTnI concentrations were significantly correlated with increasing age (Pearson's r = 0.426; P = 0.002). Future studies are warranted to investigate the diagnostic potential of plasma cTnI in Asian elephants.


Assuntos
Elefantes , Troponina I , Animais , Biomarcadores , Elefantes/sangue , Miocárdio , Plasma , Troponina I/sangue
2.
Proc Biol Sci ; 290(1990): 20222270, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36629103

RESUMO

Ivory poaching continues to threaten African elephants. We (1) used criminology theory and literature evidence to generate hypotheses about factors that may drive, facilitate or motivate poaching, (2) identified datasets representing these factors, and (3) tested those factors with strong hypotheses and sufficient data quality for empirical associations with poaching. We advance on previous analyses of correlates of elephant poaching by using additional poaching data and leveraging new datasets for previously untested explanatory variables. Using data on 10 286 illegally killed elephants detected at 64 sites in 30 African countries (2002-2020), we found strong evidence to support the hypotheses that the illegal killing of elephants is associated with poor national governance, low law enforcement capacity, low household wealth and health, and global elephant ivory prices. Forest elephant populations suffered higher rates of illegal killing than savannah elephants. We found only weak evidence that armed conflicts may increase the illegal killing of elephants, and no evidence for effects of site accessibility, vegetation density, elephant population density, precipitation or site area. Results suggest that addressing wider systemic challenges of human development, corruption and consumer demand would help reduce poaching, corroborating broader work highlighting these more ultimate drivers of the global illegal wildlife trade.


Assuntos
Elefantes , Animais , Humanos , Conservação dos Recursos Naturais/métodos , África , Crime , Fatores Socioeconômicos
3.
J Zoo Wildl Med ; 53(4): 801-810, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640083

RESUMO

Osteoarthritis (OA) is common in zoo Asian (Elephas maximus) and African (Loxodonta africana) elephants. This study investigated the relationship between confirmed or suspected OA with ovarian cyclicity, gonadotropins, progestagens, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and collagen type I (CTX-I) in zoo elephants. In Asian elephants, odds of having confirmed or suspected OA decreased with cycling (OR = 0.22, P = 0.016; OR = 0.29, P = 0.020, respectively), however, not when adjusted for age (odds ratio [OR] = 0.31, P = 0.112; OR = 0.58, P = 0.369, respectively). In African elephants, none of the models between confirmed OA and cycling status were significant (P > 0.060), while the odds of having suspected OA decreased with cycling (OR = 0.12, P = 0.001), even after adjusting for age (OR = 0.15, P = 0.005). Progestagens (Asian elephants P > 0.096; African elephants P > 0.415), LH (Asian P > 0.129; African P > 0.359), and FSH (Asian P > 0.738; African P > 0.231) did not differ with confirmed or suspected OA status, unadjusted. CTX-I concentrations were not related to OA status (P > 0.655). This study concluded hormonal changes may not have a strong impact on OA, so additional investigation into other serologic biomarkers is warranted.


Assuntos
Elefantes , Osteoartrite , Animais , Progestinas , Hormônio Luteinizante , Hormônio Foliculoestimulante , Osteoartrite/veterinária , Animais de Zoológico
4.
J Zoo Wildl Med ; 53(4): 670-678, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640068

RESUMO

Appropriate and effective antibiotic use is a critical component of veterinary medicine, but there are variations across species regarding dosage and administration of these drugs. Oral or rectal routes of administration are typically used in elephants, but not all medications can achieve adequate concentrations rectally. The fluoroquinolone antimicrobials are used in elephants because of their favorable antimicrobial spectrum and pharmacokinetics compared with other oral agents. They are commonly used as part of multiple antibiotic regimens for the treatment of tuberculosis (Mycobacterium tuberculosis). The objective of this study was to determine the pharmacokinetic profile of levofloxacin after oral and rectal administration in Asian elephants (Elephas maximus). Dosages of 5 mg/kg orally and 15 mg/kg rectally were evaluated in 13 Asian elephants. Blood was collected at various time points from 0 to 72 h for pharmacokinetic analysis. Pharmacokinetic parameters were determined and reached concentrations above minimum inhibitory concentrations of various bacterial organisms via both routes. A pharmacokinetic-pharmacodynamic assessment was used to estimate appropriate minimal inhibitory concentrations for bacteria that could be potentially treated with this antimicrobial. Based on these findings, levofloxacin may be a consideration for administration orally (5 mg/kg) and rectally (15 mg/kg) in Asian elephants. Antimicrobial stewardship principles, culture and susceptibility of suspected pathogens, and blood level monitoring should be used to tailor administration of levofloxacin in this species.


Assuntos
Anti-Infecciosos , Elefantes , Animais , Levofloxacino , Área Sob a Curva , Antibacterianos
5.
J Zoo Wildl Med ; 53(4): 791-796, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640081

RESUMO

In the Asian elephant (Elephas maximus), the levels of progesterone products 5α-pregnane, 3α-hydroxypregnane, and 17α-progesterone are elevated during pregnancy. Detection of a sudden decrease in blood progesterone product levels in the final days of pregnancy is considered an objective way of predicting impending parturition. Point-of-care (POC) tests eliminate the cost involved in transporting samples to an external laboratory and provide an almost instant result, facilitating decision-making for animal monitoring and management. This proof-of-concept study aims to investigate the ability of the AgPlus POC immunoassay system to measure 4-pregnen-3,20-dione in pregnant elephant serum samples and adapt the method for detection of the preparturient progesterone decrease. Frozen serum samples of two pregnant elephants (N = 82) and fresh serum samples of one pregnant elephant (N = 10) were analyzed using both the POC method and a radioimmunoassay in a reference laboratory. Statistical analysis of the data showed that there was no significant difference between the two methods for detection of the progesterone drop, indicating that the POC method can be considered appropriate for use in elephant parturition prediction. Refinement of the methodology, an increase of sample size, and temporal tandem radioimmunoassay would be required to further validate this method for use in elephant reproductive management.


Assuntos
Elefantes , Progesterona , Gravidez , Feminino , Animais , Cães , Sistemas Automatizados de Assistência Junto ao Leito , Reprodução , Parto
6.
Proc Natl Acad Sci U S A ; 120(5): e2201832120, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36689651

RESUMO

Megaherbivores have pervasive ecological effects. In African rainforests, elephants can increase aboveground carbon, though the mechanisms are unclear. Here, we combine a large unpublished dataset of forest elephant feeding with published browsing preferences totaling nearly 200,000 records covering >800 plant species and with nutritional data for 145 species. Elephants increase carbon stocks by: 1) promoting high wood density trees via preferential browsing on leaves from low wood density species, which are more palatable and digestible; and 2) dispersing seeds of trees that are relatively large and have the highest average wood density among tree guilds based on dispersal mode. Loss of forest elephants could cause an increase in abundance of fast-growing low wood density trees and a 6% to 9% decline in aboveground carbon stocks due to regeneration failure of elephant-dispersed trees. These results demonstrate the importance of megaherbivores for maintaining diverse, high-carbon tropical forests. Successful elephant conservation will contribute to climate mitigation at a globally-relevant scale.


Assuntos
Elefantes , Animais , Carbono/metabolismo , Florestas , Árvores/metabolismo , Clima Tropical , Biomassa
7.
Proc Natl Acad Sci U S A ; 120(1): e2211482119, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36574696

RESUMO

Balancing the competing, and often conflicting, needs of people and wildlife in shared landscapes is a major challenge for conservation science and policy worldwide. Connectivity is critical for wildlife persistence, but dispersing animals may come into conflict with people, leading to severe costs for humans and animals and impeding connectivity. Thus, conflict mitigation and connectivity present an apparent dilemma for conservation. We present a framework to address this dilemma and disentangle the effects of barriers to animal movement and conflict-induced mortality of dispersers on connectivity. We extend random-walk theory to map the connectivity-conflict interface, or areas where frequent animal movement may lead to conflict and conflict in turn impedes connectivity. We illustrate this framework with the endangered Asian elephant Elephas maximus, a species that frequently disperses out of protected areas and comes into conflict with humans. We mapped expected movement across a human-dominated landscape over the short- and long-term, accounting for conflict mortality. Natural and conflict-induced mortality together reduced expected movement and connectivity among populations. Based on model validation, our conflict predictions that explicitly captured animal movement better explained observed conflict than a model that considered distribution alone. Our work highlights the interaction between connectivity and conflict and enables identification of location-specific conflict mitigation strategies that minimize losses to people, while ensuring critical wildlife movement between habitats. By predicting where animal movement and humans collide, we provide a basis to plan for broad-scale conservation and the mutual well-being of wildlife and people in shared landscapes.


Assuntos
Conservação dos Recursos Naturais , Elefantes , Animais , Humanos , Ecossistema , Animais Selvagens , Movimento
8.
Curr Microbiol ; 80(1): 21, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36460940

RESUMO

A Gram-negative coccobacillus, YIM 103518T, isolated from wild elephant feces in Xishuangbanna, Yunnan Province, West China, was characterized and identified using a polyphasic taxonomic approach. The strain was strictly aerobic, non-motile, catalase-positive and oxidase-negative, colonies were round, convex, smooth, and pale yellow. The strain growth at 4-40 ℃ (optimum, 28 ℃), pH 6.0-10.0 (optimum, pH 7.0) and 0-4% NaCl (optimum, 0%) in culture medium YIM 38. The major fatty acids of strain YIM 103518T were summed feature 3 (C16:1 ω6c/C16:1 ω7c), C16:0, and C18:1 ω9c. The predominant ubiquinone was Q-9. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and phospholipids. The 16S rRNA gene sequence showed moderate level of similarity with Acinetobacter portensis AC 877T (98.7%), Acinetobacter sichuanensis CCTCC AB 2018118T (97.1%), and Acinetobacter cumulans CCTCC AB 2018119T (97.1%). The G+C content of the genomic DNA was 36.5 mol%. Strain YIM 103518T showed an average nucleotide identity value of 86.6%, 77.3% and 78.5%, a digital DNA-DNA hybridizations value of 31.2%, 21.9% and 23.0% with the type strain of A. portensis, A. sichuanensis and A. cumulans based on draft genome sequences, respectively. The results of the phenotypic, chemotaxonomic and phylogenetic analyses, showed that strain YIM 103518T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter faecalis sp. nov. is proposed. The type strain is YIM 103518T (=CCTCC AB 2019201T = NBRC 114057T).


Assuntos
Acinetobacter , Elefantes , Animais , RNA Ribossômico 16S/genética , Filogenia , China , Acinetobacter/genética , Fezes
9.
Sci Rep ; 12(1): 22008, 2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36550171

RESUMO

For large herbivores living in highly dynamic environments, maintaining range fidelity has the potential to facilitate the exploitation of predictable resources while minimising energy expenditure. We evaluate this expectation by examining how the seasonal range fidelity of African elephants (Loxodonta africana) in the Kruger National Park, South Africa is affected by spatiotemporal variation in environmental conditions (vegetation quality, temperature, rainfall, and fire). Eight-years of GPS collar data were used to analyse the similarity in seasonal utilisation distributions for thirteen family groups. Elephants exhibited remarkable consistency in their seasonal range fidelity across the study with rainfall emerging as a key driver of space-use. Within years, high range fidelity from summer to autumn and from autumn to winter was driven by increased rainfall and the retention of high-quality vegetation. Across years, sequential autumn seasons demonstrated the lowest levels of range fidelity due to inter-annual variability in the wet to dry season transition, resulting in unpredictable resource availability. Understanding seasonal space use is important for determining the effects of future variability in environmental conditions on elephant populations, particularly when it comes to management interventions. Indeed, over the coming decades climate change is predicted to drive greater variability in rainfall and elevated temperatures in African savanna ecosystems. The impacts of climate change also present particular challenges for elephants living in fragmented or human-transformed habitats where the opportunity for seasonal range shifts are greatly constrained.


Assuntos
Elefantes , Incêndios , Animais , Humanos , Ecossistema , Estações do Ano , Elefantes/fisiologia , África do Sul
11.
Sci Rep ; 12(1): 21148, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36522355

RESUMO

While archeologists usually favor the study of large and diagnostic lithic artifacts, this study illustrates the invaluable contribution of lithic microartifacts for interpreting hominin lifeways. Across a 64 m2 area of the Middle Pleistocene lakeshore site of Schöningen 13 II-3 in Northern Germany, we recovered a total of 57 small and micro flint artifacts, four small debris pieces, three natural fragments and three bone retouchers in close association with the skeleton of an extinct Eurasian straight-tusked elephant (Palaeoloxodon antiquus). This area lacks the type of formal knapped stone tools that would normally constitute the focus of archeological interpretations. By adopting a holistic approach, including morpho-technical analysis, experimental archeology, and use-wear and residue analyses, we demonstrate that these small and microartifacts are resharpening flakes that tell the story of the site. Fifteen resharpening flakes preserve microwear traces of processing wood. Microscopic residues of wood adhered to the former working edges of the tools corroborate this observation. Additionally, hominins used a sharp-edged, natural fragment of flint to process fresh animal tissue, which likely originates from the butchery of the elephant. These results provide unique, 300,000-year-old evidence for the functionally interconnected use of lithic, osseous and wood technologies. Furthermore, we document in-situ transformations of stone tools and the presence of both curational and expedient behaviors, thereby demonstrating the temporal depth of hominin activities at the lakeshore where the elephant died, and in the broader landscape as a whole.


Assuntos
Elefantes , Hominidae , Animais , Arqueologia , Tecnologia , Alemanha , Fósseis
12.
Elife ; 112022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36480266

RESUMO

The risk of developing cancer is correlated with body size and lifespan within species, but there is no correlation between cancer and either body size or lifespan between species indicating that large, long-lived species have evolved enhanced cancer protection mechanisms. Previously we showed that several large bodied Afrotherian lineages evolved reduced intrinsic cancer risk, particularly elephants and their extinct relatives (Proboscideans), coincident with pervasive duplication of tumor suppressor genes (Vazquez and Lynch, 2021). Unexpectedly, we also found that Xenarthrans (sloths, armadillos, and anteaters) evolved very low intrinsic cancer risk. Here, we show that: (1) several Xenarthran lineages independently evolved large bodies, long lifespans, and reduced intrinsic cancer risk; (2) the reduced cancer risk in the stem lineages of Xenarthra and Pilosa coincided with bursts of tumor suppressor gene duplications; (3) cells from sloths proliferate extremely slowly while Xenarthran cells induce apoptosis at very low doses of DNA damaging agents; and (4) the prevalence of cancer is extremely low Xenarthrans, and cancer is nearly absent from armadillos. These data implicate the duplication of tumor suppressor genes in the evolution of remarkably large body sizes and decreased cancer risk in Xenarthrans and suggest they are a remarkably cancer-resistant group of mammals.


Assuntos
Elefantes , Neoplasias , Bichos-Preguiça , Xenarthra , Animais , Xenarthra/genética , Bichos-Preguiça/genética , Tatus/genética , Filogenia , Mamíferos/genética , Elefantes/genética , Genes Supressores de Tumor , Neoplasias/epidemiologia , Neoplasias/genética , Evolução Biológica
13.
Science ; 378(6621): 696-697, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36395232

RESUMO

Paleontologists are urged to take a stand against a market that may provide cover for continued poaching.


Assuntos
Conservação dos Recursos Naturais , Crime , Elefantes , Mamutes , Animais , Fósseis
14.
Science ; 378(6621): 719, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36395237
16.
Sci Rep ; 12(1): 19982, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36411331

RESUMO

Chemical communication in elephants has been well studied at the chemical and behavioural levels. Pheromones have been identified in the Asian elephant (Elephas maximus), including (Z)-7-dodecenyl acetate and frontalin, and their specific effects on the sexual behaviour of elephants have been accurately documented. In contrast, our knowledge on the proteins mediating detection of pheromones in elephants remains poor and superficial, with only three annotated and reliable entries in sequence databases, two of them being odorant-binding proteins (OBPs), and the third a member of von Ebner's gland (VEG) proteins. Proteomic analysis of trunk wash extract from African elephant (Loxodonta africana) identified one of the OBPs (LafrOBP1) as the main component. We therefore expressed LafrOBP1 and its Asian elephant orthologue in yeast Pichia pastoris and found that both recombinant proteins, as well as the natural LafrOBP1 are tuned to (Z)-7-dodecenyl acetate, but have no affinity for frontalin. Both the natural and recombinant LafrOBP1 carry post-translational modifications such as O-glycosylation, phosphorylation and acetylation, but as these modifications affect only a very small amount of the protein, we cannot establish their potential effects on the ligand-binding properties of OBP1.


Assuntos
Elefantes , Atrativos Sexuais , Animais , Atrativos Sexuais/metabolismo , Elefantes/metabolismo , Proteômica , Feromônios/metabolismo
17.
J Healthc Eng ; 2022: 3991295, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36330360

RESUMO

In the healthcare industry, where concerns are frequently and appropriately focused on saving someone's life, access to interfaces and computer systems storing sensitive data, such as medical records, is crucial to take into account. Medical information has to be secretive and protected by the laws of privacy with restrictions on its access. E-health security is a holistic notion that encompasses available medical data's integrities and confidentiality which ensures that data are not accessed by unauthorized people and allow doctors to offer proper treatment. The patients' data need to be secured on servers holding medical data. This work adds new features for ensuring storage and access safety through ITPKLEIN-EHO (integrated transformed Paillier and KLEIN algorithms) that use EHOs (elephant herd optimizations) to provide lightweight features. The key space affects lightweight encryption techniques in general. The EHOs (elephant herd optimizations) optimize key spaces by adjusting iteration rounds. The main goal is to encrypt EEGs (electroencephalographic signals) in healthcare and send it to end users using the proposed ITPKLEIN-EHO approach. This suggested technique utilizes MATLAB for its tests on various EEG data sets for implementation. The simulations of the proposed IRPKLEIN-EHO technique are evaluated with other existing techniques in terms of MSEs, PSNRs, SSIMs, PRDs, and encryption/decryption times.


Assuntos
Segurança Computacional , Elefantes , Animais , Humanos , Confidencialidade , Algoritmos , Atenção à Saúde
18.
Sci Rep ; 12(1): 18490, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36323758

RESUMO

Animals' space requirements may vary according to life-history and social considerations. We observed 516 wild adult Asian elephants from both sexes, over 9 years, to investigate how life-history traits and social behavior influence protected-area (PA) use at Udawalawe National Park, Sri Lanka. Male PA-use, quantified in terms of average between-sightings-interval (BSI), was significantly influenced by the interaction of age class and motivational state (i.e. reproduction vs. foraging). Musth lengthened with age, with a median of 24.5 days for ages 21-30, 32.5 days for ages 31-40, and 45 days for those > 40. A minority (11%) used it exclusively during musth, while others used it exclusively for foraging (44%) or both (45%). Males using it in both states and older musth-only males were more likely to be seen across years. There were 16 social communities containing between 2-22 adult females. Females' BSI was significantly influenced by social ties, but this relationship was weak, because members of social communities do not necessarily disperse together, resulting in high individual variation in space-use. Inter-annual variability in sightings among individuals of both sexes indicates that around ¾ of the population is likely non-residential across years, challenging the prevailing fortress-conservation paradigm of wildlife management.


Assuntos
Elefantes , Animais , Feminino , Masculino , Animais Selvagens , Reprodução , Agressão , Motivação
20.
Proc Natl Acad Sci U S A ; 119(44): e2211550119, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36252102

RESUMO

The 14-carbon in animal tissues records the time that the tissues are formed; since the 1960s, using the "bomb curve" for 14C, the age of animal death can be determined accurately. Using animal tissue samples of known collection and formation dates for calibration, we determine the age of ivory samples from four ivory seizures made by law enforcement agencies between 2017 and 2019. The 14C measurements from these seizures show that most ivory in the illegal wildlife trade is from animals from recent poaching activities. However, one seizure has a large fraction of ivory that is more than 30 y old, consistent with markings on the tusks indicating they were derived from a government stockpile.


Assuntos
Elefantes , Animais , Radioisótopos de Carbono , Comércio , Conservação dos Recursos Naturais , Crime , Governo , Convulsões
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...