Comparing scapular morphology of Amblyomma sculptum and Amblyomma dubitatum nymphs allows a fast and practical differential diagnosis of ticks in highly infested areas with dominance of these two species

Rickettsia rickettsii infection causes the highest human fatality rate among all Rickettsia species of the world and is endemic in Southeast Brazil. In this part of the country most human spotted fever cases are related to unnaturally high populations of ticks, usually a mix of two species, Amblyomma dubitatum Neumann and Amblyomma sculptum Berlese and their local host, capybara (Hydrochoerus hydrochaeris). At the same time, an increase in the number of SF notifications as well as its urbanization was observed, and a better characterization of disease epidemiology is mandatory for control measures and to halt its expansion. It was recently noticed in southeast Brazil that SF endemic areas were characterized by overgrowth populations of A. sculptum and decreased populations of A. dubitatum. Hence, characterization of areas with potential to endemicity, eco-epidemiological studies and control measures may rely on the evaluation of A. sculptum/A. dubitatum rate. However, in potentially endemic scenarios, discriminating the two tick species, particularly the nymphs considered the main vector stage, is a challenge in face of several hundreds to thousands of ticks that should be examined for quantitative studies. We herein present additional morphological features to an existing identification key for Amblyomma nymphs that considerably diminishes the labor to distinguish nymphs of these two tick species. Specifically, the oval-shaped scutum of A. dubitatum and a conspicuous scapula of A. sculptum are prominent discriminating features.

     

Minimizing delay in content-centric networks using heuristics-based in-network caching

Cluster Computing - Content-centric networking (CCN) has emerged as a promising future Internet architecture that brings effective content retrieval mechanism. In CCN, the contents are accessed...     

Whistle variability of Guiana dolphins in South America: Latitudinal variation or acoustic adaptation?

A previous comparison of whistles using data sampled at 48 kHz suggested that certain frequency parameters vary along a latitudinal gradient. This geographical pattern may be biased because whistles sampled at higher frequencies could potentially have very different frequency contents. The current study compared the acoustic parameters of Guiana dolphin (Sotalia guianensis) whistles recorded at a higher sampling rate (96 kHz) and from groups occupying two never before sampled sites, Benevente Bay, Espírito Santo, Brazil, and Formosa Bay, Rio Grande do Norte, Brazil, with recordings of other populations in South America. By only considering data sampled at a rate of at least 96 kHz, we aimed to detect differences in whistles across locations. Contrary to previous findings, our analyses do not indicate any clear separation between northern and southern populations based on whistles, and do not corroborate the hypothesis of latitudinal acoustic variation in this species. The variation in Guiana dolphin whistle parameters found here appears to be influenced by latitude to some extent, but several other factors, including sampling method, environmental fluctuations, and social influence on vocal learning, may be confounding the detection of a geographic pattern in these whistle samples.     

A macroecological approach to evolutionary rescue and adaptation to climate change

Despite the widespread use of ecological niche models (ENMs) for predicting the responses of species to climate change, these models do not explicitly incorporate any population‐level mechanism. On the other hand, mechanistic models adding population processes (e.g. biotic interactions, dispersal and adaptive potential to abiotic conditions) are much more complex and difficult to parameterize, especially if the goal is to predict range shifts for many species simultaneously. In particular, the adaptive potential (based on genetic adaptations, phenotypic plasticity and behavioral adjustments for physiological responses) of local populations has been a less studied mechanism affecting species’ responses to climatic change so far. Here, we discuss and apply an alternative macroecological framework to evaluate the potential role of evolutionary rescue under climate change based on ENMs. We begin by reviewing eco‐evolutionary models that evaluate the maximum sustainable evolutionary rate under a scenario of environmental change, showing how they can be used to understand the impact of temperature change on a Neotropical anuran species, the Schneider's toad Rhinella diptycha. Then we show how to evaluate spatial patterns of species’ geographic range shift using such models, by estimating evolutionary rates at the trailing edge of species distribution estimated by ENMs and by recalculating the relative amount of total range loss under climate change. We show how different models can reduce the expected range loss predicted for the studied species by potential ecophysiological adaptations in some regions of the trailing edge predicted by ENMs. For general applications, we believe that parameters for large numbers of species and populations can be obtained from macroecological generalizations (e.g. allometric equations and ecogeographical rules), so our framework coupling ENMs with eco‐evolutionary models can be applied to achieve a more accurate picture of potential impacts from climate change and other threats to biodiversity.     

Improving the performance of nadolol stereoisomers' preparative separation using Chiralpak IA by SMB chromatography

The pseudobinary preparative separation of nadolol stereoisomers is performed by simulated moving bed chromatography (SMB). Using the Chiralpak IA adsorbent, a new 25:75:0.1 (v/v/v) methanol‐acetonitrile‐diethylamine solvent composition was selected to perform the experimental SMB separation and compare it with the previous results obtained using pure methanol. Using a 2 g L^?1 total feed concentration of an equimolar mixture of the four stereoisomers of nadolol, the more retained component was fully recovered (100% purity and 100% recovery), with a system productivity of 0.77 g L^?1 hour^?1 and a solvent consumption of 9.62 L g^?1. Comparing these results with the ones previously reported using 100:0.1 methanol‐diethylamine solvent composition, this work shows that the 25:75:0.1 methanol‐acetonitrile‐diethylamine is a better alternative for the preparative separation of nadolol stereoisomers by SMB chromatography. These results are confirmed by simulation of the SMB operation for higher feed concentrations, by comparing the performances of the two solvent compositions using the data obtained experimentally through the measurement of the adsorption equilibrium isotherms and the kinetic data obtained for both solvents. The new experimental and simulation results stress out that the performance of the preparative separation can be improved by a careful selection of the solvent composition.     

H+-dependent inorganic phosphate transporter in breast cancer cells: Possible functions in the tumor microenvironment

Tumor microenvironment has a high concentration of inorganic phosphate (Pi), which is actually a marker for tumor progression. Regarding Pi another class of transporter has been recently studied, an H⁺-dependent Pi transporter, that is stimulated at acidic pH in Caco2BBE human intestinal cells. In this study, we characterized the H⁺-dependent Pi transport in breast cancer cell (MDA-MB-231) and around the cancer tissue. MDA-MB-231 cell line presented higher levels of H⁺-dependent Pi transport as compared to other breast cell lines, such as MCF-10A, MCF-7 and T47-D. The Pi transport was linear as a function of time and exhibited a Michaelis-Menten kinetic of K_m = 1.387 ± 0.1674 mM Pi and V_max = 198.6 ± 10.23 Pi × h^?1 × mg protein^?1 hence reflecting a low affinity Pi transport. H⁺-dependent Pi uptake was higher at acidic pH. FCCP, Bafilomycin A1 and SCH28080, which deregulate the intracellular levels of protons, inhibited the H⁺-dependent Pi transport. No effect on pHi was observed in the absence of inorganic phosphate. PAA, an H⁺-dependent Pi transport inhibitor, reduced the Pi transport activity, cell proliferation, adhesion, and migration. Arsenate, a structural analog of Pi, inhibited the Pi transport. At high Pi conditions, the H⁺-dependent Pi transport was five-fold higher than the Na⁺-dependent Pi transport, thus reflecting a low affinity Pi transport. The occurrence of an H⁺-dependent Pi transporter in tumor cells may endow them with an alternative path for Pi uptake in situations in which Na⁺-dependent Pi transport is saturated within the tumor microenvironment, thus regulating the energetically expensive tumor processes.     

CXCR7 contributes to the aggressive phenotype of cholangiocarcinoma cells

Development of cholangiocarcinoma (CCA) is dependent on a cross-talk with stromal cells, which release different chemokines including CXCL12, that interacts with two different receptors, CXCR4 and CXCR7. The aim of the present study was to investigate the role of CXCR7 in CCA cells. CXCR7 is overexpressed by different CCA cell lines and in human CCA specimens. Knock-down of CXCR7 in HuCCT-1 cells reduced migration, invasion, and CXCL12-induced adhesion to collagen I. Survival of CCA was also reduced in CXCR7-silenced cells. The ability of CXCL12 to induce cell migration and survival was also blocked by CCX733, a CXCR7 antagonist. Similar effects of CXCR7 activation were observed in CCLP-1 cells and in primary iCCA cells. Enrichment of tumor stem-like cells by a 3D culture system resulted in increased CXCR7 expression compared to cells grown in monolayers, and genetic knockdown of CXCR7 robustly reduced sphere formation both in HuCCT-1 and in CCLP-1 cells. In HuCCT-1 cells CXCR7 was found to interact with β-arrestin 2, which was necessary to mediate CXCL12-induced migration, but not survival. In conclusion, CXCR7 is widely expressed in CCA, and contributes to the aggressive phenotype of CCA cells, inducing cell migration, invasion, adhesion, survival, growth and stem cell-like features. Cell migration induced by CXCR7 requires interaction with β-arrestin 2.     

The ParB homologs,Spo0J and Noc,together prevent premature midcell Z ring assembly when the early stages of replication are blocked in Bacillus subtilis

Precise cell division in coordination with DNA replication and segregation is of utmost importance for all organisms. The earliest stage of cell division is the assembly of a division protein FtsZ into a ring, known as the Z ring, at midcell. What still eludes us, however, is how bacteria precisely position the Z ring at midcell. Work in B. subtilis over the last two decades has identified a link between the early stages of DNA replication and cell division. A recent model proposed that the progression of the early stages of DNA replication leads to an increased ability for the Z ring to form at midcell. This model arose through studies examining Z ring position in mutants blocked at different steps of the early stages of DNA replication. Here, we show that this model is unlikely to be correct and the mutants previously studied generate nucleoids with different capacity for blocking midcell Z ring assembly. Importantly, our data suggest that two proteins of the widespread ParB family, Noc and Spo0J are required to prevent Z ring assembly over the bacterial nucleoid and help fine tune the assembly of the Z ring at midcell during the cell cycle.     

Effect of refrigeration storage of nemathophagous fungi embedded in sodium alginate pellets on predatory activity against asinine gastrointestinal nematodes

ABSTRACT

The objective of this study was to evaluate the effectiveness of pelleted formulations of Duddingtonia flagrans and Monacrosporium thaumasium sodium alginate matrix stored for two and five years, by refrigeration of 2–8°C, on the predation of nematode infective larvae after passage of the gastrointestinal tract of asinines. Asinines were divided into seven groups, each group containing eight animals, in which each animal received a single dose of 100?g of pellets (containing 20?g of fungal mycelia) along with commercial feed to facilitate ingestion: GI – received D. flagrans pellets stored for five years; GII- received pellets of D. flagrans stored for two years; GIII – received newly produced D. flagrans pellets; GIV – received pellets of M. thaumasium stored for five years; GV – received pellets of M. thaumasium stored for two years; GVI – received pellets of newly-stocked M. thaumasium; and Control – received pellets without nematophagous fungi. It was observed that after passage of the pellets containing D. flangras (AC001) and M. thaumasium (NF34) by the gastrointestinal tract of the asinines, regardless of pellet storage time in assays A (Petri dishes) and B (coprocultures), there was a significant larval reduction (p?<?0.01) up to 72?h. It was concluded that the use of sodium alginate matrix pellets containing D. flagrans and M. thaumasium stored for two and five years were effective on the predation of infective nematode larvae after passage of the gastrointestinal tract from asinines.     

How policies constrain native seed supply for restoration in Brazil

Large‐scale ecological restoration programs across the world involve a voluminous demand for native seeds of diverse native plant species. In this article, we explore how institutional systems have operated and impacted native seed supply in Brazil. Native seed supply for restoration is essentially a community‐based activity which faces broad barriers to operating within regulations because of requirements for excessive and costly technical documentation, scarcity of seed laboratories, and lack of instructions for native seed quality testing. Although decentralized seed networks have stimulated arrangements for local organizations to promote seed supply, policies constrain the development of local capacities and the ongoing sustainability of these organizations. These conditions have resulted in a vast network of informal collectors and producers who are largely “invisible” and unknown to the regulatory authorities. Policies have decentralized responsibilities from the state without devolving decision‐making power to the multiple stakeholders engaged in policy elaboration. The policies maintain the centralized regulation of native seed supply. After examining Brazilian seed networks' experiences and conducting discussions with stakeholders and experts, we suggest adapting the current regulations to more local level contexts, encompassing the following strategies: (1) ensuring native seed origin and identity; (2) relaxation of the laboratory accreditation process for native seed quality assurance; (3) fostering seed markets for restoration; (4) research to provide technological innovation; (5) supporting local, diverse, and small seed‐based businesses.