Large cats feeding habits have been studied through two main methods: scat analysis and the carcasses of prey killed by monitored animals. From November 2001 to April 2004, we studied jaguar ...predation patterns using GPS telemetry location clusters on a cattle ranch in southern Pantanal. During this period, we recorded 431 carcasses of animals preyed upon by monitored jaguars. Concurrently, we collected 125 jaguar scats opportunistically. We compared the frequencies of prey found through each method. We also compared the prey communities using Bray-Curtis similarity coefficient. These comparisons allowed us to evaluate the use of scat analysis as a means to describe jaguar feeding habits. Both approaches identified prey communities with high similarity (Bray-Curtis coefficient > 70). According to either method, jaguars consume three main prey: cattle (Bos taurus), caiman (Caiman yacare) and peccaries (Tayassu pecari and Pecari tajacu). The two methods did not differ in the frequency of the three main prey over dry and wet seasons or years sampled. Our results show that scat analysis is effective and capable of describing jaguar feeding habits.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A new species of tapir from the Amazon Cozzuol, Mario A.; Clozato, Camila L.; Holanda, Elizete C. ...
Journal of mammalogy,
12/2013, Letnik:
94, Številka:
6
Journal Article
Recenzirano
Odprti dostop
All known species of extant tapirs are allopatric: 1 in southeastern Asia and 3 in Central and South America. The fossil record for tapirs, however, is much wider in geographical range, including ...Europe, Asia, and North and South America, going back to the late Oligocene, making the present distribution a relict of the original one. We here describe a new species of living Tapirus from the Amazon rain forest, the 1st since T. bairdiiGill, 1865, and the 1st new Perissodactyla in more than 100 years, from both morphological and molecular characters. It is shorter in stature than T. terrestris (Linnaeus, 1758) and has distinctive skull morphology, and it is basal to the clade formed by T. terrestris and T. pinchaque (Roulin, 1829). This highlights the unrecognized biodiversity in western Amazonia, where the biota faces increasing threats. Local peoples have long recognized our new species, suggesting a key role for traditional knowledge in understanding the biodiversity of the region. Todas as espécies conhecidas de antas viventes são alopátricas: 1 no sudeste da Ásia e as 3 na América Central e América do Sul. Entretanto, o registro fóssil para antas é mais amplo geograficamente, incluindo Europa, Ásia, América do Norte e do Sul, encontrados desde o Oligoceno tardio, tornando a distribuição atual um relicto da original. Descrevemos aqui uma nova espécie de Tapirus vivente da floresta amazônica, a primeira desde T. bairdiiGill, 1865, e o primeiro novo Perissodactyla em mais de 100 anos, a partir de caracteres morfológicos e moleculares. O novo táxon é menor em estatura do que T. terrestris (Linnaeus, 1758) com morfologia distinta do crânio, sendo basal ao clado formado por T. terrestris e T. pinchaque (Roulin, 1829). Esta descoberta destaca a biodiversidade oculta no oeste da Amazônia, onde a biota enfrenta ameaças crescentes. Alguns povos locais há muito tempo reconheceram esta nova espécie, sugerindo um papel fundamental para o conhecimento tradicional na compreensão da biodiversidade da região.
We experimentally demonstrate resonance of first-order vector vortex beams (VVB) with a triangular optical cavity. We also show that, due to their symmetry properties, the VVBs commonly known as ...radial and azimuthal beams do not resonate at the same cavity length, which could be explored to use the triangular resonator as a mode sorter. In addition, an intracavity Pancharatnam phase shifter (PPS) is implemented in order to compensate for any birefringent phase that the cavity mirrors may introduce.
Short‐chain fatty acids (SCFAs), predominantly acetic, propionic, and butyric acids, are bacterial metabolites with an important role in the maintenance of homeostasis due to their metabolic and ...immunomodulatory actions. Some evidence suggests that they may also be relevant during infections. Therefore, we aimed to investigate the effects of SCFAs in the effector functions of neutrophils to an opportunistic pathogenic bacterium, Aggregatibacter actinomycetemcomitans. Using a subcutaneous model to generate a mono, isolated infection of A. actinomycetemcomitans, we demonstrated that the presence of the SCFAs in situ did not affect leukocyte accumulation but altered the effector mechanisms of migrating neutrophils by downregulating the production of cytokines, their phagocytic capacity, and killing the bacteria, thus impairing the containment of A. actinomycetemcomitans. Similar effects were observed with bacteria‐stimulated neutrophils incubated with SCFAs in vitro. These effects were independent of free‐fatty acid receptor 2 (FFAR2) activation, the main SCFA receptor expressed on neutrophils, occurring possibly through inhibition of histone deacetylases because similar effects were obtained by using histone deacetylase inhibitors, such as SAHA, MS‐275, and RGFP 966. Considering the findings of this study, we hypothesized that in an infectious condition, SCFAs may exert a detrimental effect on the host by inhibiting neutrophil's effector functions.
The remarkable radiation of South American (SA) canids produced 10 extant species distributed across diverse habitats, including disparate forms such as the short-legged, hypercarnivorous bush dog ...and the long-legged, largely frugivorous maned wolf. Despite considerable research spanning nearly two centuries, many aspects of their evolutionary history remain unknown. Here, we analyzed 31 whole genomes encompassing all extant SA canid species to assess phylogenetic relationships, interspecific hybridization, historical demography, current genetic diversity, and the molecular bases of adaptations in the bush dog and maned wolf. We found that SA canids originated from a single ancestor that colonized South America 3.9 to 3.5 Mya, followed by diversification east of the Andes and then a single colonization event and radiation of
Lycalopex
species west of the Andes. We detected extensive historical gene flow between recently diverged lineages and observed distinct patterns of genomic diversity and demographic history in SA canids, likely induced by past climatic cycles compounded by human-induced population declines. Genome-wide scans of selection showed that disparate limb proportions in the bush dog and maned wolf may derive from mutations in genes regulating chondrocyte proliferation and enlargement. Further, frugivory in the maned wolf may have been enabled by variants in genes associated with energy intake from short-chain fatty acids. In contrast, unique genetic variants detected in the bush dog may underlie interdigital webbing and dental adaptations for hypercarnivory. Our analyses shed light on the evolution of a unique carnivoran radiation and how it was shaped by South American topography and climate change.
When the vacuum state of a scalar or electromagnetic field is modified by the presence of a reflecting boundary, an interacting test particle undergoes velocity fluctuations. Such effect is regarded ...as a sort of quantum analog of the classical Brownian motion. Several aspects about this system have been recently investigated in the literature, for instance, finite temperature effects, curved spacetime framework, near-boundary regime, late time behavior, and subvacuum phenomena. Here, further steps are given in this analysis by considering the effect of vacuum fluctuations of a scalar field in the presence of a perfectly reflecting flat boundary over the motion of a scalar test particle when the background field does not satisfy the Huygens' principle. Specifically, the background field is allowed to have mass and the system is studied in D+1 dimensions. A method of implementing a smooth transition between distinct states of the field is also developed, rendering regularized analytic expressions describing the velocity fluctuations of the test particle. This method is applied to study some special behaviors of the system. Possible applications include fields known to occur in nature as, for instance, the massive Higgs' field, for which the velocity fluctuations are here predicted to acquire a characteristic oscillation, thus behaving differently from their electromagnetic counterparts.
The respiratory pattern generator modulates the sympathetic outflow, the strength of which is enhanced by challenges produced by hypoxia. This coupling is due to the respiratory-modulated ...presympathetic neurons in the rostral ventrolateral medulla (RVLM), but the underlining electrophysiological mechanisms remain unclear. For a better understanding of the neural substrates responsible for generation of this respiratory-sympathetic coupling, we combined immunofluorescence, single cell qRT-pCR, and electrophysiological recordings of the RVLM presympathetic neurons in in situ preparations from normal rats and rats submitted to a metabolic challenge produced by chronic intermittent hypoxia (CIH). Our results show that the spinally projected cathecholaminergic C1 and non-C1 respiratory-modulated RVLM presympathetic neurons constitute a heterogeneous neuronal population regarding the intrinsic electrophysiological properties, respiratory synaptic inputs, and expression of ionic currents, albeit all neurons presented persistent sodium current-dependent intrinsic pacemaker properties after synaptic blockade. A specific subpopulation of non-C1 respiratory-modulated RVLM presympathetic neurons presented enhanced excitatory synaptic inputs from the respiratory network after CIH. This phenomenon may contribute to the increased sympathetic activity observed in CIH rats. We conclude that the different respiratory-modulated RVLM presympathetic neurons contribute to the central generation of respiratory-sympathetic coupling as part of a complex neuronal network, which in response to the challenges produced by CIH contribute to respiratory-related increase in the sympathetic activity.
Flame-resistant materials are key components in buildings and several other engineering applications. In this study, flame retardancy and thermal stability were conferred to a highly flammable ...technical thermoplastic—polypropylene (PP)—upon compositing with a carbonaceous tannin-based particulate (CTP). Herein, we report on a straightforward, facile, and green approach to prepare self-extinguishing thermoplastic composites by thermoblending highly recalcitrant particulate. The thermal stability and mechanical properties of the composites are tethered to the CTP content. We demonstrate that the addition of up to 65 wt% of CTP improved the viscoelastic properties and hydrophobicity of the PP, whereas having marginal effects on bulk water interactions. Most importantly, compositing with CTP remarkably improved the thermal stability of the composites, especially over 300 °C, which is an important threshold associated with the combustion of volatiles. PP-CTP composites demonstrated great capacity to limit and stop fire propagation. Therefore, we offer an innovative route towards thermally resistant and self-extinguishing PP composites, which is enabled by sustainable tannin-based flame retardants capable of further broadening the technical range of commodity polyolefins to high temperature scenarios.
Autophagy degrades cytoplasmic components and is important for development and human health. Although autophagy is known to be influenced by systemic intercellular signals, the proteins that control ...autophagy are largely thought to function within individual cells. Here, we report that Drosophila macroglobulin complement-related (Mcr), a complement ortholog, plays an essential role during developmental cell death and inflammation by influencing autophagy in neighboring cells. This function of Mcr involves the immune receptor Draper, suggesting a relationship between autophagy and the control of inflammation. Interestingly, Mcr function in epithelial cells is required for macrophage autophagy and migration to epithelial wounds, a Draper-dependent process. This study reveals, unexpectedly, that complement-related from one cell regulates autophagy in neighboring cells via an ancient immune signaling program.
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•Macroglobulin complement-related (Mcr) functions in salivary gland cell death•Mcr regulates cell death by influencing autophagy in neighboring cells•Mcr is required in epithelial cells for macrophage migration to epithelial wounds•Mcr function in epithelial cells is required for macrophage autophagy
A complement ortholog in Drosophila plays an essential role during developmental cell death and inflammation by influencing autophagy in neighboring cells.
Differences in the selection of habitat and specific dietary items support resource partitioning and coexistence of sympatric African grazing herbivores, such as zebra and wildebeest. In Maputo ...Special Reserve (MSR), southern Mozambique, these two species were extirpated during the civil war (1977–1992); since 2010, they have been reintroduced into the Reserve. Identifying the resource selection by reintroduced species and how these species coexist, while utilising the same resources, is both of ecological interest and important for the management of wildlife communities and parks. This is a key application of our research. Therefore, the present study investigated resource partitioning between Burchell's zebra (Equus burchelli, Smuts 1832) and blue wildebeest (Connochaetes taurinus, Burchell 1823) in the MSR. We conducted the study from July 2016 to June 2017. The data were collected by direct observation, driving the vehicle along the reserve's roads that covered the vegetation communities where zebras and wildebeest are known to commonly occur. The composition of the diet and specific features of the grass grazed by the two species, including greenness, height, and the number of stems, were assessed. The widely available grass, Aristida barbicollis, contributed most to the diet of both herbivores. The dietary overlap between the two herbivores was higher during the dry season (95%) than wet season (86%). Resources partitioning appears to be determined, principally, by the height and greenness of the grass, with the zebra grazing taller grass, which may facilitate the access of the wildebeest to the greener, lower proportion of the forage. That results follow the expectation that, among native herbivores, overlap in resource use is not expected based on evolutionary segregation.
Diferenças na seleção de habitats e itens alimentares específicos promovem a partilha de recursos e a coexistência de herbívoros africanos simpátricos, tais como zebras e gnus. Em Moçambique, estas duas espécies foram quase extintas durante a guerra civil (1977‐1992); desde 2010, estão sendo reintroduzidas na Reserva Especial de Maputo (REM), no sul do país. Identificar os recursos selecionados por espécies reintroduzidas, e como essas espécies coexistem, enquanto utilizam os mesmos recursos, é de interesse ecológico, assim como importante para o manejo de comunidades e parques de vida selvagem. Esta é uma aplicação fundamental da nossa pesquisa. Portanto, o presente estudo investigou a partição de recursos entre a zebra burchelli (Equus burchelli, Smuts 1832) e gnu azul (Connochaetes taurinus, Burchell 1823) na REM. O estudo foi realizado de julho de 2016 a junho de 2017. Os dados foram coletados por observação direta, dirigindo um veículo ao longo das estradas da reserva que cobriam as comunidades de vegetação onde zebras e gnus são comumente conhecidos por ocorrer. A composição da dieta e as características específicas das gramíneas consumidas, tais como, a coloração, altura e o número de hastes, foram avaliadas. A espécie de gramínea mais disponível, Aristida barbicollis, foi à que mais contribuiu para a dieta de ambas espécies de herbívoros. A sobreposição alimentar entre as duas espécies de herbívoros foi maior durante a estação seca (95%) do que na estação chuvosa (86%). A partição de recursos parece ser determinada principalmente pela altura e pela coloração do pasto, as zebras se alimentavam de gramíneas mais altas, o que pode facilitar o acesso para os gnus à proporção mais verde e de menor altura das gramíneas. Esses resultados seguem a expectativa de que, entre os herbívoros nativos, a sobreposição no uso de recursos não é esperada com base na segregação evolutiva.
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