Thermoregulation in captive broad-snouted caiman (Caiman latirostris)

Background: Crocodilians are ectothermic animals. For this reason, the environmental temperature has substantial effects on their physiology and behavior. The thermoregulatory behavior of these animals involves the selective use of different types of environments. This behavior enables them to reach the temperature level for their metabolic activities. This study aimed to determine the influence of sex, body size, and reproductive stage on the body temperature (T b) of adult broad-snouted caiman (Caiman latirostris) in captivity. Thermal sensors were surgically implanted in the peritoneal cavity of 16 adult females and 4 adult males and programmed to register T b hourly during 6 months. Results: The diel T b pattern of the broad-snouted caiman reflected the variation among the microenvironmental temperatures used by the species (water surface, pool bottom, and ground). The sex of the animals had influence on their T b, but body size did not. Reproductive females had higher T b than non-reproductive females during October to early November. It is possible that this difference is a result of the ovulation period of the species. Sick animals appeared to show behavioral fever. Conclusions: The results of the present study suggest that several factors can affect the T b of adult broad-snouted caiman in captivity. Future studies should focus on the possible effect of thermoregulatory behavior on individuals' growth rate and reproductive performance.Fil: Bassetti, Luís A. B.. Universidade de Sao Paulo; BrasilFil: Marques, Thiago S.. Universidade de Sao Paulo; BrasilFil: Malvásio, Adriana. Universidade Federal do Tocantins; BrasilFil: Piña, Carlos Ignacio. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Autónoma de Entre Ríos. Facultad de Ciencia y Tecnología; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ciencias de la Alimentación; ArgentinaFil: Verdade, Luciano M.. Universidade de Sao Paulo; Brasi

First passages in bounded domains: When is the mean first passage time meaningful?

We study the first passage statistics to adsorbing boundaries of a Brownian motion in bounded two-dimensional domains of different shapes and configurations of the adsorbing and reflecting boundaries. From extensive numerical analysis we obtain the probability P(\omega) distribution of the random variable \omega=\tau_1/(\tau_1+\tau_2), which is a measure for how similar the first passage times \tau_1 and \tau_2 are of two independent realisations of a Brownian walk starting at the same location. We construct a chart for each domain, determining whether P(\omega) represents a unimodal, bell-shaped form, or a bimodal, M-shaped behaviour. While in the former case the mean first passage time (MFPT) is a valid characteristic of the first passage behaviour, in the latter case it is an insufficient measure for the process. Strikingly we find a distinct turnover between the two modes of P(\omega), characteristic for the domain shape and the respective location of absorbing and reflective boundaries. Our results demonstrate that large fluctuations of the first passage times may occur frequently in two-dimensional domains, rendering quite vague the general use of the MFPT as a robust measure of the actual behaviour even in bounded domains, in which all moments of the first passage distribution exist.Comment: 9 pages, 6 figure

Understanding Drought Dynamics during Dry Season in Eastern Northeast Brazil

Eastern Northeast Brazil (ENEB) generally experiences a high variability in precipitation in the dry season, with amplitudes that can overcome 500mm. The understanding of this variability can help in mitigating the socio-economic issues related to the planning and management of water resources this region, which is highly vulnerable to drought. This work aims to assess spatio-temporal variability of precipitation during the dry season and investigate the relationships between climate phenomena and drought events in the ENEB, using univariate (Spearman correlation) and multivariate statistical techniques, such as Principal Component Analysis, Cluster Analysis, and Maximum Covariance Analysis. The results indicate that the variability of precipitation in the dry season can be explained mainly (62%) by local physical conditions and climate conditions have a secondary contribution. Further analysis of the larger anomalous events suggests that the state of Atlantic and Pacific oceans can govern the occurrence of those events, and the conditions of Atlantic Ocean can be considered a potential modulator of anomalous phenomena of precipitation in ENEB

Probing Surface Effects on α-NaYF4 Nanoparticles by Nuclear Magnetic Resonance

The structural properties of insulating α-NaYF4 (cubic) nanoparticles with size ranging within 4-25 nm were investigated by high-resolution 23Na and 19F solid-state nuclear magnetic resonance (NMR) spectroscopy under magic angle spinning (MAS) with single-pulse (SP-MAS), spin-echo (SE-MAS), inversion recovery, and 3Q-MAS experiments. The 23Na SP-MAS spectra show a broad peak around -18 ppm with a shoulder around -9 ppm, which becomes more prominent for the smallest nanoparticles. The 23Na nuclei resonating around -9 ppm demonstrate a longitudinal relaxation time of a few milliseconds, while the ones resonating around -18 ppm are on the order of 50-125 ms. This feature is noticed for all studied nanoparticles, but it is more evident for the smallest ones (φ ≲ 7 nm), especially among the batches with higher polydispersity. On the basis of these relaxation times, field-dependent measurements, and 23Na 3Q-MAS, we attributed the signal around -18 ppm to 23Na in the bulk of the nanoparticles and the signal around -9 ppm to surface or/and sites near defects, featuring higher fluctuations in the electric field gradient (EFG). The 23Na 3Q-MAS spectra provide evidence for two (and sometimes three) distinct Na sites in α-NaYF4 with similar quadrupole coupling but slightly different chemical shifts. The 19F SE-MAS spectra show a broad peak around -75 ppm with a small shoulder around -120 ppm corresponding to only ≈1% of the signal. The peak around -75 ppm is attributed to the stoichiometric NaYF4 composition, and its broadening is attributed to a distribution of Na- and Y-rich environments. The minor shoulder around -120 ppm is associated with the F-deficient NaYF4 structure. The 19F spin-spin relaxation time indicates some degree of mobility of the fluorine atoms, possibly due to the presence of F vacancies triggering hopping-like ion motion. The signal related to the F-deficient structure is greatly enhanced for the smallest nanoparticles (φ = 4 nm), i.e., along with the increase of 23Na surface effects and defects. Therefore, we correlate several NMR techniques to provide a fundamental structural view for nanoparticles used as upconversion host systems with prominent technological applications. Particularly for α-NaYF4, significant surface effects and defects must be expected for nanoparticles with dimensions in the order of few nanometers (φ ≲ 7 nm).Fil: de Queiroz, Thiago B.. Universidad Federal do Abc; BrasilFil: Cabrera Baez, Michael. Universidade Federal de Pernambuco; BrasilFil: Menegasso, Paulo. Universidade Estadual de Campinas; BrasilFil: Martínez, Eduardo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: García Flores, Ali F.. Universidade Estadual de Campinas; BrasilFil: Rettori, Carlos. Universidad Federal do Abc; BrasilFil: Urbano, Ricardo R.. Universidade Estadual de Campinas; Brasi

Physicochemical properties and cell viability of shrimp chitosan films as affected by film casting solvents. I-potential use as wound dressing

: Chitosan solubility in aqueous organic acids has been widely investigated. However, most of the previous works have been done with plasticized chitosan films and using acetic acid as the film casting solvent. In addition, the properties of these films varied among studies, since they are influenced by different factors such as the chitin source used to produce chitosan, the processing variables involved in the conversion of chitin into chitosan, chitosan properties, types of acids used to dissolve chitosan, types and amounts of plasticizers and the film preparation method. Therefore, this work aimed to prepare chitosan films by the solvent casting method, using chitosan derived from Litopenaeus vannamei shrimp shell waste, and five different organic acids (acetic, lactic, maleic, tartaric, and citric acids) without plasticizer, in order to evaluate the effect of organic acid type and chitosan source on physicochemical properties, degradation and cytotoxicity of these chitosan films. The goal was to select the best suited casting solvent to develop wound dressing from shrimp chitosan films. Shrimp chitosan films were analyzed in terms of their qualitative assessment, thickness, water vapor permeability (WVP), water vapor transmission rate (WVTR), wettability, tensile properties, degradation in phosphate buffered saline (PBS) and cytotoxicity towards human fibroblasts using the resazurin reduction method. Regardless of the acid type employed in film preparation, all films were transparent and slightly yellowish, presented homogeneous surfaces, and the thickness was compatible with the epidermis thickness. However, only the ones prepared with maleic acid presented adequate characteristics of WVP, WVTR, wettability, degradability, cytotoxicity and good tensile properties for future application as a wound dressing material. The findings of this study contributed not only to select the best suited casting solvent to develop chitosan films for wound dressing but also to normalize a solubilization protocol for chitosan, derived from Litopenaeus vannamei shrimp shell waste, which can be used in the pharmaceutical industry.info:eu-repo/semantics/publishedVersio

The first Caipirasuchus (Mesoeucrocodylia, Notosuchia) from the Late Cretaceous of Minas Gerais, Brazil: new insights on sphagesaurid anatomy and taxonomy

Field work conducted by the staff of the Centro de Pesquisas Paleontológicas Llewellyn Ivor Price of the Universidade Federal do Triângulo Mineiro since 2009 at Campina Verde municipality (MG) have resulted in the discovery of a diverse vertebrate fauna from the Adamantina Formation (Bauru Basin). The baurusuchid Campinasuchus dinizi was described in 2011 from Fazenda Três Antas site and after that, preliminary descriptions of a partial crocodyliform egg, abelisaurid teeth, and fish remains have been done. Recently, the fossil sample has been considerably increased including the discovery of several, partially articulated fish remains referred to Lepisosteiformes and an almost complete and articulated skeleton referred to a new species of Caipirasuchus (Notosuchia, Sphagesauridae), which is the main subject of this contribution. At present, this genus was restricted to the Adamantina Formation cropping out in São Paulo state, with the species Caipirasuchus montealtensis, Caipirasuchus paulistanus, and Caipirasuchus stenognathus. The new material represents the holotype of a new species, Caipirasuchus mineirus n. sp., diferenciated from the previously ones due to the following traits: last two maxillary teeth located posterior to anterior edge of infraorbital fenestra, elongated lateroventral maxillo-jugal suture—about ½ the anteroposterior maxillar length—and contact between posterior crest of quadrate and posterior end of squamosal forming an almost 90° flaring roof of the squamosal, among others. C. mineirus was found in the same outcrop than Campinasuchus but stratigraphically the former occurs in the lower portion of the section with no unambiguous data supporting the coexistance of both taxa

Does early specialization provide an advantage in physical fitness development in youth basketball?

The present study examined the influence of the specialization onset on the magnitude and patterns of changes in basketball-specific physical fitness within a competitive season and developmental fitness trends between 11 and 17 years in young basketball players. Repeated measures of 181 young basketball players (female, n = 40; male, n = 141) were examined. Anthropometry, age, estimated maturity status, and basketball-specific physical fitness (assessed with the countermovement jump, line drill, and yo-yo intermittent recovery level-1 and fitness score) were considered. Players were grouped by the onset of specialization as related to biological maturation milestones (pre-puberty, mid-puberty, and late-puberty specialization). The within-season and developmental changes in physical fitness were fitted using multilevel modeling in a fully Bayesian framework. The fitness outcomes were similar between-player and within-player changes when grouped by specialization across a season. Fitness improvements across a season were apparent for female players, while male players maintained their performance levels. There was no variation in the patterns of physical fitness development between 11 and 17 years associated with the onset of specialization. Conditional on our data and models, the assumption that early sport specialization provides a physical fitness advantage for future athletic success does not hold

Hard X-ray-Induced Valence Tautomeric Interconversion in Cobalt-o-Dioxolene Complexes

Valence tautomeric interconversion (VTI) is a reversible process occurring in metal complexes in which an intramolecular metal–ligand electron transfer is accompanied by a change of metal ion spin state, creating two switchable electronic states (redox isomers). Herein, we describe the low-temperature, 30–100 K, single-crystal study of the [Co(diox)2(4-CN-py)2]·benzene complex (1) (diox = 3,5-di-t-butylsemiquinonate (SQ•-) and/or 3,5-di-t-butylcatecholate (Cat2–) radical; 4-CN-py = 4-cyano-pyridine) using hard synchrotron X-ray radiation with different intensities. We demonstrate for the first time that hard X-rays can induce VTI, and that the interconversion molar fraction is dependent on both intensity and exposure time. This in turn shows that X-rays, as a probe, might be altering the very nature of many structures under investigation at low temperatures, and consequently their properties. Our findings add new perspectives to VTI studies and might be of significant interest to the entire community investigating photoresponsive complexes

Reconciling biome-wide conservation of an apex carnivore with land-use economics in the increasingly threatened Pantanal wetlands

Conservation of carnivores involves finding solutions to minimize habitat loss and human-wildlife conflict. Understanding the nature of land-use economics can allow us to mitigate both threats. In the Pantanal, the two main economic activities are cattle ranching and ecotourism, each of which directly and indirectly affect the persistence of jaguars (Panthera onca). To understand how the geography of these economic activities is related to jaguar populations, we developed a jaguar distribution model (JDM), livestock density model, and ecotourism lodge density model for the Pantanal. Due to the recent wildfires within the Pantanal, we also assess the impact of burnt areas that are suitable for jaguars, cattle ranching, and tourism. Our JDM indicate that 64% of the Pantanal holds suitable habitat for jaguars. However, jaguar habitat suitability was positively correlated with ecotourism, but negatively correlated with areas most suitable for intensive cattle-ranching. This demonstrates a biome-wide scenario compatible with jaguar conservation. Of particular concern, recent wildfires overlap most suitable areas for jaguars. If wildfires become increasingly frequent, this would represent a serious threat to jaguars and many other wildlife populations. We emphasize the global importance of the Pantanal wetland ecoregion as a key stronghold for long-term jaguar conservation

miR-155 in the progression of lung fibrosis in systemic sclerosis

Background\ud MicroRNA (miRNA) control key elements of mRNA stability and likely contribute to the dysregulated lung gene expression observed in systemic sclerosis associated interstitial lung disease (SSc-ILD). We analyzed the miRNA gene expression of tissue and cells from patients with SSc-ILD. A chronic lung fibrotic murine model was used.\ud \ud Methods\ud RNA was isolated from lung tissue of 12 patients with SSc-ILD and 5 controls. High-resolution computed tomography (HRCT) was performed at baseline and 2–3 years after treatment. Lung fibroblasts and peripheral blood mononuclear cells (PBMC) were isolated from healthy controls and patients with SSc-ILD. miRNA and mRNA were analyzed by microarray, quantitative polymerase chain reaction, and/or Nanostring; pathway analysis was performed by DNA Intelligent Analysis (DIANA)-miRPath v2.0 software. Wild-type and miR-155 deficient (miR-155ko) mice were exposed to bleomycin.\ud \ud Results\ud Lung miRNA microarray data distinguished patients with SSc-ILD from healthy controls with 185 miRNA differentially expressed (q < 0.25). DIANA-miRPath revealed 57 Kyoto Encyclopedia of Genes and Genomes pathways related to the most dysregulated miRNA. miR-155 and miR-143 were strongly correlated with progression of the HRCT score. Lung fibroblasts only mildly expressed miR-155/miR-21 after several stimuli. miR-155 PBMC expression strongly correlated with lung function tests in SSc-ILD. miR-155ko mice developed milder lung fibrosis, survived longer, and weaker lung induction of several genes after bleomycin exposure compared to wild-type mice.\ud \ud Conclusions\ud miRNA are dysregulated in the lungs and PBMC of patients with SSc-ILD. Based on mRNA-miRNA interaction analysis and pathway tools, miRNA may play a role in the progression of the disease. Our findings suggest that targeting miR-155 might provide a novel therapeutic strategy for SSc-ILD