Recent studies document the LH-releasing pathway of nerve growth factor (NGF) in male camelids and that the LH response to seminal NGF is associated with elevated plasma testosterone concentration. ...Results provide rationale for the hypothesis that NGF in semen is associated with male fertility. In Experiment 1, the association between the amount of NGF in the ejaculate and characteristics of the male reproductive system was examined in alpacas. The concentration of NGF was measured by radioimmunoassay in semen samples collected from male alpacas (n = 47) and correlated with sperm morphology and motility, and measurements of the male reproductive anatomy. Most ejaculates had NGF concentrations that, based on previous studies, triggered ovulation in female camelids, however, we only found a positive correlation between NGF concentration with sperm concentration, thread formation and total NGF, and a negative correlation with pH. In Experiment 2, a retrospective analysis was carried out to determine if breeding performance during the previous season was related to recent concentrations of seminal NGF in male alpacas (n = 22). Birth rates tended to be correlated with sperm concentration and total amount of NGF in the ejaculate (P = 0.09). Experiment 3 was a prospective study to determine the relationship between seminal NGF (n = 8 male alpacas) and ovulation and pregnancy rates in a breeding trial. No association was detected between seminal NGF concentration and ovulation rate, pregnancy rate, or LH response in the female. We conclude that among the breeding males used in our study, the abundance of seminal NGF was correlated with sperm concentration and thread formation, however, it was not predictive of male fertility in alpacas. Examination of males not previously selected as breeding stock may be expected to include a broader range of seminal NGF and provide a more comprehensive understanding of the relationship between seminal NGF and male fertility.
Bruton tyrosine kinase (Btk) has a well-defined role in B-cell development, whereas its expression in osteoclasts (OCs) further suggests a role in osteoclastogenesis. Here we investigated effects of ...PCI-32765, an oral and selective Btk inhibitor, on osteoclastogenesis as well as on multiple myeloma (MM) growth within the BM microenvironment. PCI-32765 blocked RANKL/M-CSF–induced phosphorylation of Btk and downstream PLC-γ2 in OCs, resulting in diminished TRAP5b (ED50 = 17nM) and bone resorption activity. PCI-32765 also inhibited secretion of multiple cytokines and chemokines from OC and BM stromal cell cultures from both normal donors (ED50 = 0.5nM) and MM patients. It decreased SDF-1–induced migration of MM cells, and down-regulated MIP1-α/CCL3 in MM cells. It also blocked MM cell growth and survival triggered by IL-6 or coculture with BM stromal cells or OCs in vitro. Importantly, PCI-32765 treatment significantly inhibits in vivo MM cell growth (P < .03) and MM cell–induced osteolysis of implanted human bone chips in SCID mice. Moreover, PCI-32765 prevents in vitro colony formation by stem-like cells from MM patients. Together, these results delineate functional sequelae of Btk activation mediating osteolysis and growth of MM cells, supporting evaluation of PCI-32765 as a novel therapeutic in MM.
Tropical deforestation is one of the most pressing threats to biodiversity, and substantially reduces ecosystem services at the global scale. Little is known however about the global spatial ...distribution of the actors behind tropical deforestation. Newly available maps of global cropland field size offer an opportunity to gain understanding towards the spatial distribution of tropical deforestation actors. Here we use a map of global cropland field size and combine it with maps of forest loss to study the spatial association between field size and deforestation while accounting for other anthropogenic and geographical drivers of deforestation. We then use linear mixed-effects models and bootstrapping to determine what factors affect field sizes within deforested areas across all countries in the global tropics and subtropics. We find that field size within deforested areas is largely determined by country-level effects indicating the importance of socio-economic, cultural and institutional factors on the distribution of field sizes. Typically, small field sizes appear more commonly in deforested areas in Africa and Asia while the association was with larger field sizes in Australia and the Americas. In general, we find that smaller field sizes are associated with deforestation in protected areas and large field sizes with areas with lower agricultural value, although these results have low explanatory power. Our results suggest that the spatial patterns of actors behind deforestation are aggregated geographically which could help target conservation and sustainable land-use strategies.
Positive sap pressures are produced in the xylem of birch trees in boreal conditions during the time between the thawing of the soil and bud break. During this period, xylem embolisms accumulated ...during wintertime are refilled with water. The mechanism for xylem sap pressurization and its environmental drivers are not well known. We measured xylem sap flow, xylem sap pressure, xylem sap osmotic concentration, xylem and whole stem diameter changes, and stem and root non-structural carbohydrate concentrations, along with meteorological conditions at two sites in Finland during and after the sap pressurisation period. The diurnal dynamics of xylem sap pressure and sap flow during the sap pressurisation period varied, but were more often opposite to the diurnal pattern after bud burst, i.e. sap pressure increased and sap flow rate mostly decreased when temperature increased. Net conversion of soluble sugars to starch in the stem and roots occurred during the sap pressurisation period. Xylem sap osmotic pressure was small in comparison to total sap pressure, and it did not follow changes in environmental conditions or tree water relations. Based on these findings, we suggest that xylem sap pressurisation and embolism refilling occur gradually over a few weeks through water transfer from parenchyma cells to xylem vessels during daytime, and then the parenchyma are refilled mostly during nighttime by water uptake from soil. Possible drivers for water transfer from parenchyma cells to vessels are discussed. Also the functioning of thermal dissipation probes in conditions of changing stem water content is discussed.
•Recent yellow fever outbreaks in Africa and Brazil have brought this virus back to the spotlight.•Yellow fever outbreaks have revealed important limitations of the current vaccination system.•There ...has been a global expansion of arboviruses like dengue, chikungunya and zika.•Arboviral outbreaks due to Aedes mosquitoes have occurred in North America and Europe in this decade.•Unless preventive measures are implemented, yellow fever might soon reach North America and Europe.
Yellow fever virus historically was a frequent threat to American and European coasts. Medical milestones such as the discovery of mosquitoes as vectors and subsequently an effective vaccine significantly reduced its incidence, in spite of which, thousands of cases of this deathly disease still occur regularly in Sub-Saharan Africa and the Amazonian basin in South America, which are usually not reported. An urban outbreak in Angola, consecutive years of increasing incidence near major Brazilian cities, and imported cases in China, South America and Europe, have brought this virus back to the global spotlight. The aim of this article is to underline that the preventive YFV measures, such as vaccination, need to be carefully revised in order to minimize the risks of new YFV outbreaks, especially in urban or immunologically vulnerable places. Furthermore, this article highlights the diverse factors that have favored the spread of other Aedes spp.-associated arboviral diseases like Dengue, Chikungunya and Zika, to northern latitudes causing epidemics in the United States and Europe, emphasizing the possibility that YFV might follow the path of these viruses unless enhanced surveillance and efficient control systems are urgently initiated.
Conservation science needs to engage the general public to ensure successful conservation interventions. Although online technologies such as Twitter and Facebook offer new opportunities to ...accelerate communication between conservation scientists and the online public, factors influencing the spread of conservation news in online media are not well understood. We explored transmission of conservation research through online news articles with generalized linear mixed-effects models and an information theoretic approach. In particular, we assessed differences in the frequency conservation research is featured on online news sites and the impact of online conservation news content and delivery on Facebook likes and shares and Twitter tweets. Five percent of articles in conservation journals are reported in online news, and the probability of reporting depended on the journal. There was weak evidence that articles on climate change and mammals were more likely to be featured. Online news articles about charismatic mammals with illustrations were more likely to be shared or liked on Facebook and Twitter, but the effect of news sites was much larger. These results suggest journals have the greatest impact on which conservation research is featured and that news site has the greatest impact on how popular an online article will be on Facebook and Twitter. La ciencia de la conservación necesita envolver al público en general para asegurar intervenciones exitosas de conservación. Aunque tecnologías en línea como Twitter y Facebook ofrecen nuevas oportunidades para acelerar la comunicación entre los científicos de la conservación y el público en línea, los factores que influyen sobre el esparcimiento de las noticias de conservación en los medios en línea no están bien entendidos. Exploramos la transmisión de la investigación de la conservación a través de artículos en línea con modelos lineales generalizados de efectos mixtos y un enfoque teórico de información. En particular, evaluamos las diferencias en la frecuencia con la que la investigación de la conservación es incluida en sitios en línea de noticias y el impacto del contenido y la forma de comunicarse de las noticias de conservación sobre los "likes" y número de veces que se comparte en Facebook y sobre los tuits en Twitter. El 5% de los artículos de las revistas de conservación se reportan en noticias en línea y la probabilidad de reportar dependió de la revista. Hubo evidencias débiles de que los artículos sobre el cambio climático y los mamíferos tuvieran mayor probabilidad de ser incluidos. Las noticias en línea sobre mamíferos carismáticos con ilustraciones fueron más probables de ser compartidas o que obtuvieran "likes" en Facebook y Twitter, pero el efecto de los sitios de noticias fue mucho mayor. Estos resultados sugieren que las revistas tienen el mayor impacto sobre cuál investigación se incluye y que los sitios de noticias tienen el mayor impacto sobre cuán popular será un artículo en Facebook o Twitter.
The reconciliation of biodiversity conservation, ecosystem service provision and agricultural production in tropical landscapes requires recognition of the trade-offs between competing land-uses. It ...is especially relevant for conservation planning to assess whether the economic value of ecosystem services is spatially congruent with biodiversity. Previous analyses have largely focused on ecosystem service provision or assumed homogeneous economic values across land uses within biomes. We relax this assumption by carrying out a spatially explicit meta-analysis based on 30 studies of ecosystem service values in tropical forests from The Economics of Ecosystems and Biodiversity (TEEB) database, while controlling for economic, environmental and methodological variables. Our results demonstrate a lack of spatial congruence between the economic value of ecosystem services and biodiversity in tropical forests. Instead, we find that economic value presents a nonlinear inverted-U relationship with site accessibility and economic activity, highlighting the importance of matching supply and demand between each ecosystem service and its beneficiaries for economic values to be realized. The implications are that conservation policies focusing solely on the economic value of ecosystem services will fail to protect biodiversity in remote and less disturbed regions.
•The actin and microtubule cytoskeletons build the synapse architecture that supports the organization of signaling modules.•Mitochondria might be the main energy supplier, in form of ATP, for ...functioning of the immune synapse.•Actomyosin-mediated forces have a major role for antigen extraction and endocytosis at the synapse.•Non-canonical B cell synapses, the other engine that governs the B lymphocyte response.
B cell receptor (BCR)-mediated antigen-specific recognition activates B lymphocytes and drives the humoral immune response. This enables the generation of antibody-producing plasma cells, the effector arm of the B cell immune response, and of memory B cells, which confer protection against additional encounters with antigen. B cells search for cognate antigen in the complex cellular microarchitecture of secondary lymphoid organs, where antigens are captured and exposed on the surface of different immune cells. While scanning the cell network, the BCR can be stimulated by a specific antigen and elicit the establishment of the immune synapse with the antigen-presenting cell. At the immune synapse, an integrin-enriched supramolecular domain is assembled at the periphery of the B cell contact with the antigen-presenting cell, ensuring a stable and long-lasting interaction. The coordinated action of the actomyosin cytoskeleton and the microtubule network in the inner B cell space provides a structural framework that integrates signaling events and antigen uptake through the generation of traction forces and organelle polarization. Accordingly, the B cell immune synapse can be envisioned as a temporal engine that drives the molecular mechanisms needed for successful B cell activation. Here, I review different aspects of the B cell synapse engine and provide insights into other aspects poorly known or virtually unexplored.
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