Species distribution models and climatic niche comparisons provide clues on the geographic origin of a spider invasion in the Americas

Identifying the source population of alien species is important to assess the distribution and potential effects in the invaded area. The araneid spider Cyrtophora citricola is widely distributed in Europe, Asia, and Africa; however, in the last 26 years, it has been reported in several countries across the Americas. To date, the geographic origin of the populations established in the Americas remains unclear, but considering the successful colonization after its recent arrival, assessing climatic similarities between the invaded and native geographic ranges could be useful to address this question. In this study, we used a combination of Species Distribution Models and Ordination Methods to assess the climatic match between the invaded region (the Americas) and two potential origins (southern Africa and the Mediterranean) aiming to determine the more likely origin for the populations established in the Americas. We found that the American populations of C. citricola occupy sites with climatic conditions more similar to those occupied by southern African populations, than to those occupied by the Mediterranean populations. Therefore, our results suggest a southern African rather than a Mediterranean origin for the populations established in America. In addition, our results also show that populations in America are spreading into sites that differ in climate conditions from those occupied by native populations. Further studies assessing intrinsic (e.g., physiological tolerances, plasticity, behavior, reproduction) and extrinsic (physical barriers, predator release) factors could provide further information to disentangle the mechanisms behind the geographic and climatic niche expansion of this species

Actitud y creencias relacionadas con la violencia y desgaste por empatía en efectivos policiales de las comisarías de Cajamarca

Esta investigación se propuso examinar la conexión entre las actitudes y creencias asociadas con la violencia y el desgaste por empatía en el cuerpo policial de Cajamarca. Se optó por un enfoque de investigación básica - cuantitativa, empleando un diseño correlacional no experimental de corte transversal. La aplicación de los cuestionarios EACV y ESAPE se llevó a cabo en una muestra representativa de 255 efectivos policiales de Cajamarca, seleccionados mediante un riguroso muestreo no probabilístico por conveniencia. Los resultados obtenidos revelaron patrones significativos de relación entre las actitudes y creencias en torno a la violencia, y el desgaste por empatía, la vulnerabilidad y diversas influencias dentro del cuerpo policial de Cajamarca. No obstante, es importante señalar que la involucración personal no demostró una asociación estadísticamente significativa con las dimensiones de actitudes y creencias evaluadas. Estos hallazgos aportan una perspectiva valiosa sobre los factores que influyen en la percepción y respuesta de los efectivos policiales en la región de Cajamarca

Gene Expression Analysis of Zebrafish Heart Regeneration

Mammalian hearts cannot regenerate. In contrast, zebrafish hearts regenerate even when up to 20% of the ventricle is amputated. The mechanism of zebrafish heart regeneration is not understood. To systematically characterize this process at the molecular level, we generated transcriptional profiles of zebrafish cardiac regeneration by microarray analyses. Distinct gene clusters were identified based on temporal expression patterns. Genes coding for wound response/inflammatory factors, secreted molecules, and matrix metalloproteinases are expressed in regenerating heart in sequential patterns. Comparisons of gene expression profiles between heart and fin regeneration revealed a set of regeneration core molecules as well as tissue-specific factors. The expression patterns of several secreted molecules around the wound suggest that they play important roles in heart regeneration. We found that both platelet-derived growth factor-a and -b (pdgf-a and pdgf-b) are upregulated in regenerating zebrafish hearts. PDGF-B homodimers induce DNA synthesis in adult zebrafish cardiomyocytes. In addition, we demonstrate that a chemical inhibitor of PDGF receptor decreases DNA synthesis of cardiomyocytes both in vitro and in vivo during regeneration. Our data indicate that zebrafish heart regeneration is associated with sequentially upregulated wound healing genes and growth factors and suggest that PDGF signaling is required

TIMP-1 Induces an EMT-Like Phenotypic Conversion in MDCK Cells Independent of Its MMP-Inhibitory Domain

Matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) regulate epithelial-mesenchymal transition (EMT) critical for the development of epithelial organs as well as cancer cell invasion. TIMP-1 is frequently overexpressed in several types of human cancers and serves as a prognostic marker. The present study investigates the roles of TIMP-1 on the EMT process and formation of the lumen-like structure in a 3D Matrigel culture of MDCK cells. We show that TIMP-1 overexpression effectively prevents cell polarization and acinar-like structure formation. TIMP-1 induces expression of the developmental EMT transcription factors such as SLUG, TWIST, ZEB1 and ZEB2, leading to downregulation of epithelial marker and upregulation of mesenchymal markers. Importantly, TIMP-1′s ability to induce the EMT-like process is independent of its MMP-inhibitory domain. To our surprise, TIMP-1 induces migratory and invasive properties in MDCK cells. Here, we present a novel finding that TIMP-1 signaling upregulates MT1-MMP and MMP-2 expression, and potentiates MT1-MMP activation of pro-MMP-2, contributing to tumor cell invasion. In spite of the fact that TIMP-1, as opposed to TIMP-2, does not interact with and inhibit MT1-MMP, TIMP-1 may act as a key regulator of MT1-MMP/MMP-2 axis. Collectively, our findings suggest a model in which TIMP-1 functions as a signaling molecule and also as an endogenous inhibitor of MMPs. This concept represents a paradigm shift in the current view of TIMP-1/MT1-MMP interactions and functions during cancer development/progression

Human Cytomegalovirus Induces TGF-β1 Activation in Renal Tubular Epithelial Cells after Epithelial-to-Mesenchymal Transition

Human cytomegalovirus (HCMV) infection is associated epidemiologically with poor outcome of renal allografts due to mechanisms which remain largely undefined. Transforming growth factor-β1 (TGF-β1), a potent fibrogenic cytokine, is more abundant in rejecting renal allografts that are infected with either HCMV or rat CMV as compared to uninfected, rejecting grafts. TGF-β1 induces renal fibrosis via epithelial-to-mesenchymal transition (EMT) of renal epithelial cells, a process by which epithelial cells acquire mesenchymal characteristics and a migratory phenotype, and secrete molecules associated with extracellular matrix deposition and remodeling. We report that human renal tubular epithelial cells infected in vitro with HCMV and exposed to TGF-β1 underwent morphologic and transcriptional changes of EMT, similar to uninfected cells. HCMV infected cells after EMT also activated extracellular latent TGF-β1 via induction of MMP-2. Renal epithelial cells transiently transfected with only the HCMV IE1 or IE2 open reading frames and stimulated to undergo EMT also induced TGF-β1 activation associated with MMP-2 production, suggesting a role for these viral gene products in MMP-2 production. Consistent with the function of these immediate early gene products, the antiviral agents ganciclovir and foscarnet did not inhibit TGF-β1 production after EMT by HCMV infected cells. These results indicate that HCMV infected renal tubular epithelial cells can undergo EMT after exposure to TGF-β1, similar to uninfected renal epithelial cells, but that HCMV infection by inducing active TGF-β1 may potentiate renal fibrosis. Our findings provide in vitro evidence for a pathogenic mechanism that could explain the clinical association between HCMV infection, TGF-β1, and adverse renal allograft outcome

Increased resting perfusion of the hippocampus in high positive schizotypy: A pseudocontinuous arterial spin labeling study

Arterial spin labeling (ASL) provides absolute quantification of resting tissue cerebral blood flow (CBF) as an entirely noninvasive approach with good reproducibility. As a result of neurovascular coupling, ASL provides a useful marker of resting neuronal activity. Recent ASL studies in individuals at clinical high risk of psychosis (CHR) have reported increased resting hippocampal perfusion compared with healthy controls. Schizotypy refers to the presence of subclinical psychotic-like experiences in healthy individuals and represents a robust framework to study neurobiological mechanisms involved in the extended psychosis phenotype while avoiding potentially confounding effects of antipsychotic medications or disease comorbidity. Here we applied pseudo-continuous ASL to examine differences in resting CBF in 21 subjects with high positive schizotypy (HS) relative to 22 subjects with low positive schizotypy (LS), as determined by the Oxford and Liverpool Inventory of Feelings and Experiences. Based on preclinical evidence that hippocampal hyperactivity leads to increased activity in mesostriatal dopamine projections, CBF in hippocampus, midbrain, and striatum was assessed. Participants with HS showed higher CBF of the right hippocampus compared to those with LS (p 5 .031, family-wise error corrected). No differences were detected in the striatum or midbrain. The association between increased hippocampal CBF and HS supports the notion that hippocampal hyperactivity might be a central characteristic of the extended psychosis phenotype, while hyperactivity in subcortical dopamine pathways may only emerge at a higher intensity of psychotic experiences.Wellcome Trust and the Royal Societ

The role of epigynal setae in mate choice in the orb-weaver Leucauge argyra

Male and female genital morphology may have strong effects on fitness in spiders. Females of some species of Leucauge produce mating plugs that partially or totally block the entrances to their insemination ducts on the epigynum, forming barriers that reduce the probabilities of future inseminations. While in some species both females and males participate in plug formation, the mating plugs in L. argyra are produced exclusively by females. The epigynum of L. argyra (Walckenaer 1841) is unusual in having a prominent ventral process covered on its anterior side and around its base with long, thick setae. We tested whether male stimulation of these epigynal setae affected female plug formation by removing them from some females but not others. Females lacking setae produced mating plugs immediately after copulation less often than unmanipulated females. However, 24 hr later the mating plugs had disappeared in many females of the treatment group. Setae removal did not affect the amount of sperm stored in the female spermatheca, or the frequency of female attacks. The rate of male genital inflations correlated positively, but mating duration was negatively correlated with sperm stored in female’s spermathecae. Females attempted to attack small males more often than large males. These findings contribute to our understanding of the function of the setae associated with the female genitalia, and the effect of their tactile stimulation on plug formation, and transference of spermatozoids