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We describe Argolebias adrianae, a new species of killifish from a small temporary wetland in the Paraná Forest ecoregion with no regular or predictable temporal pattern of water availability. This habitat is in the Lower Iguazú River Basin, known for its high fish endemism, but until now, only two species of Rivulidae were reported from it, but from the Araucarian Forest ecoregion. The genus Argolebias was previously only known from the lower portions of the Paraguay, Paraná, and Uruguay basins and middle Paraná. The new species is distinguished from all congeners by its unique coloration, which includes a conspicuously dark grey anterior third portion of the dorsal fin and the absence of iridescent spots on the basal half of the pectoral fin in live adult males, as well as dark grey spots on the anterocentral portion of the flanks of females. Our phylogenetic analysis shows A. adrianae to be closely related to Argolebias guarani from the adjacent Middle Paraná basin. We also provide data on the ecology, ontogeny of coloration, and chorion ornamentation of this species. Our findings have important implications for understanding the biogeography, ecology, and evolution of mechanisms that enable organisms to thrive in highly stochastic environments like this one. [ABSTRACT FROM AUTHOR]

Copyright of Laboratory Animals is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Killifishes (Cyprinodontiformes) are a group of fish that include a high proportion of small-bodied species living in seasonal aquatic habitats, with narrow geographical distributions and high human impact. They are among the most vulnerable vertebrates in the Neotropical region, with nearly half of the species in threat categories. Herein, we propose a new phylogenetic hypothesis of the Rivulidae genus Austrolebias , based on 10 genes (six nuclear and four mitochondrial) and 191 morphological characters, including 90% of the total valid species of this genus. An updated definition and diagnosis of the existing subgenera of Austrolebias is provided, and these are erected to genera. Also, four new genera are erected to accommodate the taxonomy of the group to the current phylogenetic hypothesis. Additionally, we describe Argolebias guarani sp. nov. , from a seasonal pond in the Middle Paraná River basin, which is diagnosed by a unique colour pattern. This addition reinforces this area as a biodiversity hotspot of endemicity and highlights the importance of this region for conservation. Data on the ontogenetic changes in colour pattern, chorion ornamentation of the egg and ecology of this species are also provided. [ABSTRACT FROM AUTHOR]

The historical biogeography of the major South American forested biomes has long intrigued scientists. Paleoclimatic events during the last 130 thousand years promoted connections between forested biomes in the Neotropical region, leading to disjunct distributions of some of the biota. In this context, MacConnell's Bat, Mesophylla macconnelli, appears to represent a forest-restricted species with its current distribution bisected by dry areas. In this study, we infer past connections between the Amazonia and Atlantic Forest using MacConnell's Bat and ecological niche models. We obtained 681 records of the species, and estimated its potential distribution during the Last Interglacial (LIG), Last Glacial Maximum (LGM), and current periods. Our generated models, based on 260 filtered occurrence records, had very good predictive power, with AUC and TSS adherence values above 0.9. Temperature seasonality and annual precipitation had the highest relative contribution. The potential distribution for the LIG suggested a suitable area connection between the southwestern Atlantic Forest and southern Cerrado and Amazonia. The potential distribution in the LGM suggests range expansion toward northern and eastern Amazonia. The current and inferred past distributions of Mesophylla macconnelli suggest at least two periods of past connection between Amazon and Atlantic Forest. This pattern is found in other forest-associated vertebrates in South America, suggesting that Pleistocene climatic cycles were central to the generation of disjunct distributions in the region. La biogeografía histórica de los principales biomas de selvas de América del Sur ha intrigado a los científicos durante mucho tiempo. Los eventos paleoclimáticos durante los últimos 130 mil años promovieron conexiones entre biomas de selvas en la región neotropical, lo que llevó a distribuciones disjuntas de parte de la biota. En este contexto, el murciélago de MacConnell, Mesophylla macconnelli, parece ser un ejemplo de especie restringida al bosque con su distribución actual atravesada por las áreas secas de América del Sur. En este estudio, inferimos las conexiones pasadas entre la Amazonía y el Bosque Atlántico utilizando modelos de nicho ecológico y el murciélago de MacConnell. Obtuvimos 681 registros de la especie, y estimamos su distribución potencial durante el Último Interglacial (LIG), Último Máximo Glacial (LGM) y períodos actuales. Nuestros modelos generados, basados en 260 registros de ocurrencia filtrados, tuvieron muy buen poder predictivo, con valores de adherencia AUC y TSS superiores a 0.9. La estacionalidad de la temperatura y la precipitación anual tuvieron la mayor contribución relativa. La distribución potencial en el LIG sugiere una conexión de área adecuada entre el suroeste del Bosque Atlántico y el sur del Cerrado y la Amazonía. La distribución potencial en el LGM sugiere una expansión del rango hacia el norte y el este de la Amazonía. Las distribuciones actuales y pasadas inferidas de Mesophylla macconnelli sugieren al menos dos períodos de conexión pasada entre la Amazonía y el Bosque Atlántico. Este patrón se encuentra en otros vertebrados asociados a los bosques en América del Sur, lo que sugiere que los ciclos climáticos del Pleistoceno fueron fundamentales para la generación de distribuciones disjuntas en la región. [ABSTRACT FROM AUTHOR]

Background: Strongyloides stercoralis is an intestinal nematode unique in its ability to replicate in the human host, allowing ongoing cycles of autoinfection, persisting for decades within the same host. Although usually asymptomatic, overwhelming infections can occur in Strongyloides and HTLV-1 co-infected individuals (SS/HTLV-1). Regulatory T cells (Tregs) are able to blunt specific Th2 responses necessary to control the parasite. We previously reported that peripheral blood Tregs are increased in SS/HTLV-1 and correlate with low Th2 responses. We hypothesized that Tregs are also increased at the site of infection in duodenal mucosa. Methods: Paraffin embedded duodenal biopsies were obtained from 10 SS/HTLV-1 patients, 3 controls with non-parasitic chronic duodenitis, and 2 healthy controls. Immunohistochemistry was performed using monoclonal antibodies against human CD3, CD8, IgE and FoxP3. The number of cells were counted using a conventional light microscope. The number of CD3+, CD8+, FP3+ and IgE positive cells per 0.35 mm2 was measured using ImagePro Plus software comparing areas adjacent or distant from parasite material. Results: In patients with SS/HTLV-1, T lymphocyte counts and CD8+ cells were lower in areas adjacent to the parasite compared to non-adjacent areas (CD3+: adjacent: 6.5 [Interquartile range (IQR: 2.8–12.3)]; non-adjacent: 24.5 [IQR: 20.9–34.4]; Mann-Whitney p = 0.0003; CD8+: adjacent: 4.5 [IQR: 2.3–11.8]; non-adjacent: 21 [IQR: 15.3–42.9]; Mann-Whitney p = 0.0011). Tregs cells in the intestines (FoxP3+ expressing cells) were increased in patients with SS/HTLV-1 compared with patients with chronic duodenitis (SS/HTLV-1: 1.5 [IQR: 0.7–2.3]; duodenitis controls: 0 [range 0–0.7]; healthy controls: 0; Mann-Whitney p = 0.034). There was also a trend towards fewer eosinophils adjacent to the parasites. Among SS/HTLV-1 patients the number of IgE expressing cells was increased for in areas not adjacent to the parasite compared to non-adjacent areas (ANOVA, p = 0.001). Conclusions: Our data shows increased Treg cell numbers localized adjacent to the parasites in the duodenum SS/HTLV-1 patients. In addition, other T lymphocytes and IgE expressing cells were decreased adjacent to the parasites, suggesting an important role for Tregs in down-regulating local parasite effector responses. [ABSTRACT FROM AUTHOR]

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cryptic species meet the biological definition of species, but are morphologically identical or quite similar. Several ecological studies underestimate richness and neglect important information on cryptic species, as they are rather difficult to identify. Among insects, drosophilids of the willistoni subgroup, which includes Drosophila willistoni Sturtevant, Drosophila paulistorum Dobzhansky & Pavan, Drosophila equinoxialis Dobzhansky, Drosophila tropicalis Burla & da Cunha, Drosophila insularis Dobzhansky, and Drosophila pavlovskiana Kastritsis & Dobzhansky, are good examples of cryptic species. Although several studies have shown that this subgroup is one of the most abundant in the Neotropical region, no identification to species level has been reported for areas where these individuals live in sympatry. This study evaluates the seasonal oscillations in abundance of this subgroup in biomes with contrasting vegetation and rainfall regimes: the Caatinga and the Atlantic Forest, in northeastern Brazil. Approximately 39,000 drosophilids were captured in 24 collections, of which 18,000 belonged to the willistoni subgroup. The most abundant were D. willistoni, D. paulistorum, and D. equinoxialis, in this order. D. equinoxialis was recorded in only one of the environments surveyed, represented by few individuals. In all environments, individuals of the willistoni subgroup were more abundant in the rainy season, when richness often was higher. The results underline the importance of humidity and of temperature for the subgroup willistoni and indicate the ecological versatility of some of its species. [ABSTRACT FROM AUTHOR]

Due to the lack of studies with a regional focus on the richness and distribution of the fauna of chiropterans in northeastern Brazil, this paper presents a collection of these data gathered in an extensive literature review. The data analyzed include technical reports of environment consulting agencies, abstracts presented in scientific meetings, monographs, dissertations, theses, papers, scientific notes, short communications, book chapters and books on bats of South America, Brazil and the biomes Amazon, Caatinga, Cerrado and Atlantic Forest. The numbers of municipalities surveyed per biome and the localities, municipalities and species richness for each state and biome in northeastern Brazil were determined. This information indicated the regions lacking more consistent Chiroptera sampling efforts, namely large areas in the Amazon, Caatinga and Cerrado. However, bat surveys in Atlantic Forest environments in most northeastern Brazilian states were considered representative. Although bat populations in some states have been poorly surveyed, the results of this review afford to conclude that a large part of the diversity of bat species known in Brazil has been reported for the northeastern region of the country. This review enlarges the knowledge on bat species richness and distribution in northeastern Brazil, and indicates areas suffering from wide survey gaps. [ABSTRACT FROM AUTHOR]

• Parabrachiella mugilis is genetically different from P. exilis. • We confirmed the validity of three copepod species parasitic on mugilids. • We report for the first time the COI sequences of Parabrachiella fasciata, P. oralis and P. dispar. • We report for the first time the COI sequences of P. chevreuxi from Argentina. The parasitic copepod genus Parabrachiella is composed of 70 species, 14 of which are found in South America. The finding of new specimens of Parabrachiella mugilis from Turkey allowed us to compare the nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene of this species with those of the South American Parabrachiella exilis and Parabrachiella platensis ; all these species are parasites of mugilids. In addition, specimens of Parabrachiella fasciata, Parabrachiella oralis and Parabrachiella dispar from Chile, and Parabrachiella chevreuxi from Argentina were included in the comparison. Our results confirmed that the three Parabrachiella species parasitizing mugilids, which had been identified by morphology, are valid entities. However, P. exilis was recently synonymized with P. mugilis. The latter species showed a great genetic distance from P. exilis (16%) and was closer to Parabrachiella fasciata (13%) and to species with long posterior processes. Parabrachiella exilis and P. platensis (parasite on Mugil cephalus and Mugil liza, respectively) had a low genetic distance (9%) and Parabrachiella kabatai (parasite of Isacia conceptionis) had a low genetic distance (12-13%) from P. fasciata, P. platensis and P. exilis. In addition, the three parasitic copepods from South America have short and round posterior processes compared to other species, which have long posterior processes. Most species with long posterior processes are clustered together in a Pacific Ocean clade (P. hugu from the North Pacific Ocean), with the exception of P. chevreuxi , which has been found in the South Atlantic Ocean. This study adds seven new sequences, making a total of nine sequenced South American species of Parabrachiella. [ABSTRACT FROM AUTHOR]

Research of human T lymphotropic virus type I (HTLV-1)-associated diseases is mostly focused on inflammatory and lymphoproliferative disorders. However, the immunosuppressive consequences of HTLV-1 infection are frequently ignored. In developing countries where exposure to parasitic and other tropical diseases is frequent, the burden of disease is significantly increased by opportunistic infections. Regulatory T cells (Tregs) are a CD4 T-cell subset capable of suppressing effector responses. During HTLV-1 infection, CD4+Foxp3+ cells are increased in HTLV-1-associated leukaemia/lymphoma (ATLL) as well as in non-leukaemic presentations. However, controversy exists regarding the actual regulatory function of these cells. In this report, we present two cases of HTLV-1 ATLL complicated by parasitic organisms and we provide a brief review of the literature regarding FoxP3+ regulatory T cells and their role as a possible mechanism for the immunosuppressive manifestations that take place during HTLV-1 infection. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Tregs) blunt uncontrolled immune responses. In advanced human immunodeficiency virus (HIV) infection, the total number of Tregs is decreased, but the proportion of T cells with a regulatory phenotype is highly variable. We studied CD4+CD25+FoxP3+ T cells from patients successfully treated with combination antiretroviral therapy (ART). The proportion of CD4+CD25+FoxP3+ cells transiently increased and then decreased from a median of 13% at baseline to 5.1% at 48 weeks, similar to values in normal subjects. These data suggest that with effective therapy, the regulatory cell numbers normalize, and that the inflammatory signals driving their production may also abate. [ABSTRACT FROM AUTHOR]

Background: Human strongyloidiasis varies from a chronic but limited infection in normal hosts to hyperinfection in patients treated with corticosteroids or with HTLV-1 co-infection. Regulatory T cells dampen immune responses to infections. How human strongyloidiasis is controlled and how HTLV-1 infection affects this control are not clear. We hypothesize that HTLV-1 leads to dissemination of Strongyloides stercoralis infection by augmenting regulatory T cell numbers, which in turn down regulate the immune response to the parasite. Objective: To measure peripheral blood T regulatory cells and Strongyloides stercoralis larval antigen-specific cytokine responses in strongyloidiasis patients with or without HTLV-1 co-infection. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from newly diagnosed strongyloidiasis patients with or without HTLV-1 co-infection. Regulatory T cells were characterized by flow cytometry using intracellular staining for CD4, CD25 and FoxP3. PBMCs were also cultured with and without Strongyloides larval antigens. Supernatants were analyzed for IL-5 production. Results: Patients with HTLV-1 and Strongyloides co-infection had higher parasite burdens. Eosinophil counts were decreased in the HTLV-1 and Strongyloides co-infected subjects compared to strongyloidiasis-only patients (70.0 vs. 502.5 cells/mm3, p = 0.09, Mann-Whitney test). The proportion of regulatory T cells was increased in HTLV-1 positive subjects co-infected with strongyloidiasis compared to patients with only strongyloidiasis or asymptomatic HTLV-1 carriers (median = 17.9% vs. 4.3% vs. 5.9 p<0.05, One-way ANOVA). Strongyloides antigen-specific IL-5 responses were reduced in strongyloidiasis/HTLV-1 co-infected patients (5.0 vs. 187.5 pg/ml, p = 0.03, Mann-Whitney test). Reduced IL-5 responses and eosinophil counts were inversely correlated to the number of CD4+CD25+FoxP3+ cells. Conclusions: Regulatory T cell counts are increased in patients with HTLV-1 and Strongyloides stercoralis co-infection and correlate with both low circulating eosinophil counts and reduced antigen-driven IL-5 production. These findings suggest a role for regulatory T cells in susceptibility to Strongyloides hyperinfection. Author Summary: Human strongyloidiasis varies from a mild, controlled infection to a severe frequently fatal disseminated infection depending on the hosts. Patients infected with the retrovirus HTLV-1 have more frequent and more severe forms of strongyloidiasis. It is not clear how human strongyloidiasis is controlled by the immune system and how HTLV-1 infection affects this control. We hypothesize that HTLV-1 leads to dissemination of Strongyloides stercoralis by augmenting regulatory T cell numbers, which in turn down regulate the immune response to the parasite. In our study, patients with HTLV-1 and Strongyloides co-infection had higher parasite burdens than patients with only strongyloidiasis. Eosinophils play an essential role in control of strongyloidiasis in animal models, and eosinophil counts were decreased in the HTLV-1 and Strongyloides stercoralis co-infected subjects compared to patients with only strongyloidiasis. The proportion of T cells with a regulatory cell phenotype was increased in HTLV-1 positive subjects co-infected with strongyloidiasis compared to patients with only strongyloidiasis. IL-5 is a key host molecule in stimulating eosinophil production and activation, and Strongyloides stercoralis antigen-specific IL-5 responses were reduced in strongyloidiasis/HTLV-1 co-infected patients. Reduced IL-5 responses and eosinophil counts were inversely correlated to the number of regulatory T cells. These findings suggest a role for regulatory T cells in susceptibility to Strongyloides hyperinfection. [ABSTRACT FROM AUTHOR]

Abstract: Flow cytometry provides accurate relative cellular quantitation (percent abundance) of cells from diverse samples, but technical limitations of most flow cytometers preclude accurate absolute quantitation. Several quantitation standards are now commercially available which, when added to samples, permit absolute quantitation of CD4+ T cells. However, these reagents are limited by their cost, technical complexity, requirement for additional software and/or limited applicability. Moreover, few studies have validated the use of such reagents in complex biological samples, especially for quantitation of non-T cells. Here we show that addition to samples of known quantities of polystyrene fluorescence standardization beads permits accurate quantitation of CD4+ T cells from complex cell samples. This procedure, here termed single bead-enhanced cytofluorimetry (SBEC), was equally capable of enumerating eosinophils as well as subcellular fragments of apoptotic cells, moieties with very different optical and fluorescent characteristics. Relative to other proprietary products, SBEC is simple, inexpensive and requires no special software, suggesting that the method is suitable for the routine quantitation of most cells and other particles by flow cytometry. [Copyright &y& Elsevier]

The accumulating evidence linking bacteria in the gut and neurons in the brain (the microbiota–gut–brain axis) has led to a paradigm shift in the neurosciences. Understanding the neurobiological mechanisms supporting the relevance of actions mediated by the gut microbiota for brain physiology and neuronal functioning is a key research area. In this review, we discuss the literature showing how the microbiota is emerging as a key regulator of the brain's function and behavior, as increasing amounts of evidence on the importance of the bidirectional communication between the intestinal bacteria and the brain have accumulated. Based on recent discoveries, we suggest that the interaction between diet and the gut microbiota, which might ultimately affect the brain, represents an unprecedented stimulus for conducting new research that links food and mood. We also review the limited work in the clinical arena to date, and we propose novel approaches for deciphering the gut microbiota–brain axis and, eventually, for manipulating this relationship to boost mental wellness. [ABSTRACT FROM AUTHOR]

A multispectral backscattering LiDAR (Light detection and range) system (hereafter Oculus) was integrated into a wave glider and used to estimate the scattering order (i.e., single vs multiple collisions) of LIDAR backscattering, the water inherent optical properties (IOPs), the biogeo-chemical characteristics of particulate scatterers (i.e., relative size, composition) and their motion) on shelf waters of South East Florida. Oculus has a dual-wavelength configuration (473 and 532 nm) and two detection geometries (off- and on-axis). Characteristics of scatterers were investigated based on two complementary LiDAR-derived proxies (the Structural Dissimilarity Index and the spectral slope of LiDAR backscattering). In March 2017, field measurements showed a covariation between direct and diffuse backscattering contributions during morning hours and away from shore. LiDAR attenuation coefficients explained up to 57% of IOPs variability. The analysis of LiDAR-derived proxies suggested higher turbidity and larger particulates near the coast [ABSTRACT FROM AUTHOR]

Shallow-water depth estimates from airborne lidar data might be improved by using sounding attribute data (SAD) and ocean geomorphometry derived from lidar soundings. Moreover, an accurate derivation of geomorphometry would be beneficial to other applications. The SAD examined here included routinely collected variables such as sounding intensity and fore/aft scan direction. Ocean-floor geomorphometry was described by slope, orientation, and pulse orthogonality that were derived from the depth estimates of bathymetry soundings using spatial extrapolation and interpolation. Four data case studies (CSs) located near Key West, Florida (United States) were the testbed for this study. To identify bathymetry soundings in lidar point clouds, extreme gradient boosting (XGB) models were fitted for all seven possible combinations of three variable suites—SAD, derived geomorphometry, and sounding depth. R2 values for the best models were between 0.6 and 0.99, and global accuracy values were between 85% and 95%. Lidar depth alone had the strongest relationship to bathymetry for all but the shallowest CS, but the SAD provided demonstrable model improvements for all CSs. The derived geomorphometry variables contained little bathymetric information. Whereas the SAD showed promise for improving the extraction of bathymetry from lidar point clouds, the derived geomorphometry variables do not appear to describe geomorphometry well. [ABSTRACT FROM AUTHOR]