scholarly journals Using reliable predator identification to investigate feeding habits of Neotropical carnivores (Mammalia, Carnivora) in a deforestation frontier of the Brazilian Amazon

Mammalia ◽  
2019 ◽  
Vol 83 (5) ◽  
pp. 415-427 ◽  
Author(s):  
Flávia P. Tirelli ◽  
Thales R.O. de Freitas ◽  
Fernanda Michalski ◽  
Alexandre R. Percequillo ◽  
Eduardo Eizirik

Abstract Accurate identification of predator species is a critical requirement to investigate their diet using faecal samples. We used non-invasive sampling and two methods of predator identification to investigate the diets of sympatric carnivores in a highly deforested region of the Brazilian Amazon. Of 108 scats, 81 could be identified at the species level using DNA sequencing and/or trichology. The former performed better than the latter (81.5% vs. 54.3% of the identified samples), and results were quite congruent (89.7% concordance in the 29 samples that could be assessed with both approaches). Nine species were identified, out of which four (crab-eating fox, ocelot, puma and jaguar) presented a sufficient number of samples to allow dietary analyses. The crab-eating fox was the most generalist (BA=0.92); ocelots focused on small- to medium-sized prey; pumas fed mostly on medium-sized items; and jaguars mostly targeted large-sized prey. A considerable overlap was observed between ocelots and pumas in all estimations (O=0.47–0.83). The presence of jaguars in the same region could be driving pumas to select medium- and small-sized prey. The results of this study highlight the importance of reliable predator identification and the need for in-depth ecological studies in areas where carnivore species are sympatric.

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 243
Author(s):  
Julieta Rousseau ◽  
Mónia Nakamura ◽  
Helena Rio-Maior ◽  
Francisco Álvares ◽  
Rémi Choquet ◽  
...  

Sarcoptic mange is globally enzootic, and non-invasive methods with high diagnostic specificity for its surveillance in wildlife are lacking. We describe the molecular detection of Sarcoptes scabiei in non-invasively collected faecal samples, targeting the 16S rDNA gene. We applied this method to 843 Iberian wolf Canis lupus signatus faecal samples collected in north-western Portugal (2006–2018). We further integrated this with serological data (61 samples from wolf and 20 from red fox Vulpes vulpes, 1997–2019) in multi-event capture–recapture models. The mean predicted prevalence by the molecular analysis of wolf faecal samples from 2006–2018 was 7.2% (CI95 5.0–9.4%; range: 2.6–11.7%), highest in 2009. The mean predicted seroprevalence in wolves was 24.5% (CI95 18.5–30.6%; range: 13.0–55.0%), peaking in 2006–2009. Multi-event capture–recapture models estimated 100% diagnostic specificity and moderate diagnostic sensitivity (30.0%, CI95 14.0–53.0%) for the molecular method. Mange-infected individually identified wolves showed a tendency for higher mortality versus uninfected wolves (ΔMortality 0.150, CI95 −0.165–0.458). Long-term serology data highlights the endemicity of sarcoptic mange in wild canids but uncovers multi-year epidemics. This study developed and evaluated a novel method for surveying sarcoptic mange in wildlife populations by the molecular detection of S. scabiei in faecal samples, which stands out for its high specificity and non-invasive character.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3124
Author(s):  
Charles Farber ◽  
A. S. M. Faridul Islam ◽  
Endang M. Septiningsih ◽  
Michael J. Thomson ◽  
Dmitry Kurouski

Digital farming is a modern agricultural concept that aims to maximize the crop yield while simultaneously minimizing the environmental impact of farming. Successful implementation of digital farming requires development of sensors to detect and identify diseases and abiotic stresses in plants, as well as to probe the nutrient content of seeds and identify plant varieties. Experimental evidence of the suitability of Raman spectroscopy (RS) for confirmatory diagnostics of plant diseases was previously provided by our team and other research groups. In this study, we investigate the potential use of RS as a label-free, non-invasive and non-destructive analytical technique for the fast and accurate identification of nutrient components in the grains from 15 different rice genotypes. We demonstrate that spectroscopic analysis of intact rice seeds provides the accurate rice variety identification in ~86% of samples. These results suggest that RS can be used for fully automated, fast and accurate identification of seeds nutrient components.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2323
Author(s):  
Lloyd A. Courtenay ◽  
Darío Herranz-Rodrigo ◽  
José Yravedra ◽  
José Mª Vázquez-Rodríguez ◽  
Rosa Huguet ◽  
...  

Human populations have been known to develop complex relationships with large carnivore species throughout time, with evidence of both competition and collaboration to obtain resources throughout the Pleistocene. From this perspective, many archaeological and palaeontological sites present evidence of carnivore modifications to bone. In response to this, specialists in the study of microscopic bone surface modifications have resorted to the use of 3D modeling and data science techniques for the inspection of these elements, reaching novel limits for the discerning of carnivore agencies. The present research analyzes the tooth mark variability produced by multiple Iberian wolf individuals, with the aim of studying how captivity may affect the nature of tooth marks left on bone. In addition to this, four different populations of both wild and captive Iberian wolves are also compared for a more in-depth comparison of intra-species variability. This research statistically shows that large canid tooth pits are the least affected by captivity, while tooth scores appear more superficial when produced by captive wolves. The superficial nature of captive wolf tooth scores is additionally seen to correlate with other metric features, thus influencing overall mark morphologies. In light of this, the present study opens a new dialogue on the reasons behind this, advising caution when using tooth scores for carnivore identification and contemplating how elements such as stress may be affecting the wolves under study.


1965 ◽  
Vol 8 (3) ◽  
pp. 281-290 ◽  
Author(s):  
Ruth Beckey Irwin ◽  
Ivan Paul Krafchick

An audio-visual test was developed for ascertaining ability inrecognizing misarticulations. Two films, each with a different set of 23 words representing 23 initial and 20 final sounds, were produced. Each test included 138 consonant sounds in phrases, 276 in isolated words, and 144 in trios of words. An empirical “correct” answer sheet was prepared by two experienced clinicians after repeated viewings of the films. Six children with misarticulations presented stimuli in the films. One-hundred-fifty subjects included speech clinicians with five or more years of experience, graduating senior majors in speech pathology, and experienced teachers. Each subject took three tests: Film A (audio-visual), Film B (audio-visual), and the sound-track of Film A presented without motion pictures (audio only). Correctly identified misarticulations, falsely identified misarticulations, and total correct responses were tabulated. Both forms of the audio-visual test were considered valid since the clinicians and students were significantly better than the teachers in identifying misarticulations. Satisfactory reliability was also established, since Films A and B were not significantly different in the accurate identification of sounds in words. Performance was significantly better for audio-visual representation than for audio only; and identification of misarticulation was best with isolated words and worst with phrases. Experienced teachers did not identify 12 of the sounds as accurately as experienced clinicians.


2018 ◽  
Vol 24 (2) ◽  
pp. 250-269 ◽  
Author(s):  
João Arthur Pompeu Pavanelli ◽  
João Roberto dos Santos ◽  
Lênio Soares Galvão ◽  
Maristela Xaud ◽  
Haron Abrahim Magalhães Xaud

Abstract: In northern Brazilian Amazon, the crops, savannahs and rainforests form a complex landscape where land use and land cover (LULC) mapping is difficult. Here, data from the Operational Land Imager (OLI)/Landsat-8 and Phased Array type L-band Synthetic Aperture Radar (PALSAR-2)/ALOS-2 were combined for mapping 17 LULC classes using Random Forest (RF) during the dry season. The potential thematic accuracy of each dataset was assessed and compared with results of the hybrid classification from both datasets. The results showed that the combination of PALSAR-2 HH/HV amplitudes with the reflectance of the six OLI bands produced an overall accuracy of 83% and a Kappa of 0.81, which represented an improvement of 6% in relation to the RF classification derived solely from OLI data. The RF models using OLI multispectral metrics performed better than RF models using PALSAR-2 L-band dual polarization attributes. However, the major contribution of PALSAR-2 in the savannahs was to discriminate low biomass classes such as savannah grassland and wooded savannah.


2012 ◽  
Vol 69 (3) ◽  
pp. 217-225 ◽  
Author(s):  
Boris Volkoff ◽  
Francisco Fujita de Castro Mello ◽  
Stoécio Malta Ferreira Maia ◽  
Carlos Eduardo Pellegrino Cerri

2018 ◽  
Vol 12 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Julia P. Slopsema ◽  
John M. Boss ◽  
Lane A. Heyboer ◽  
Carson M. Tobias ◽  
Brooke P. Draggoo ◽  
...  

Background: Electrical stimulation is increasingly relevant in a variety of medical treatments. In this study, surface electrical stimulation was evaluated as a method to non-invasively target a neural function, specifically natural sensation in the distal limbs. Method: Electrodes were placed over the median and ulnar nerves at the elbow and the common peroneal and lateral sural cutaneous nerves at the knee. Strength-duration curves for sensation were compared between nerves. The location, modality, and intensity of each sensation were also analyzed. In an effort to evoke natural sensations, several patterned waveforms were evaluated. Results: Distal sensation was obtained in all but one of the 48 nerves tested in able-bodied subjects and in the two nerves from subjects with an amputation. Increasing the pulse amplitude of the stimulus caused an increase in the area and magnitude of the sensation in a majority of subjects. A low frequency waveform evoked a tapping or tapping-like sensation in 29 out of the 31 able-bodied subjects and a sensation that could be considered natural in two subjects with an amputation. This waveform performed better than other patterned waveforms that had proven effective during implanted extra-neural stimulation. Conclusion: Surface electrical stimulation has the potential to be a powerful, non-invasive tool for activation of the nervous system. These results suggest that a tapping sensation in the distal extremity can be evoked in most able-bodied individuals and that targeting the nerve trunk from the surface is a valid method to evoke sensation in the phantom limb of individuals with an amputation for short term applications.


2021 ◽  
Vol 17 (2) ◽  
pp. e1008635
Author(s):  
Gerrit Ansmann ◽  
Tobias Bollenbach

Many ecological studies employ general models that can feature an arbitrary number of populations. A critical requirement imposed on such models is clone consistency: If the individuals from two populations are indistinguishable, joining these populations into one shall not affect the outcome of the model. Otherwise a model produces different outcomes for the same scenario. Using functional analysis, we comprehensively characterize all clone-consistent models: We prove that they are necessarily composed from basic building blocks, namely linear combinations of parameters and abundances. These strong constraints enable a straightforward validation of model consistency. Although clone consistency can always be achieved with sufficient assumptions, we argue that it is important to explicitly name and consider the assumptions made: They may not be justified or limit the applicability of models and the generality of the results obtained with them. Moreover, our insights facilitate building new clone-consistent models, which we illustrate for a data-driven model of microbial communities. Finally, our insights point to new relevant forms of general models for theoretical ecology. Our framework thus provides a systematic way of comprehending ecological models, which can guide a wide range of studies.


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