Behavioral interference and facilitation in the foraging cycle shape the functional response

Individual forager behaviors should affect per capita intakerates and thereby population and consumer-resource properties.We consider and incorporate conspecific facilitation and interferenceduring the separate foraging-cycle stages in a functional responsemodel that links individual behavioral interactions with consumer-resourceprocesses. Our analyses suggest that failing to properly considerand include all effects of behavioral interactions on foraging-cyclestage performances may either over- or underestimate effectsof interactions on the shape of both functional responses andpredator zero-growth isoclines. Incorporation of prey- and predator-dependentinteractions among foragers in the model produces predator isoclineswith potentials for highly complex consumer-resource dynamics.Facilitation and interference during the foraging cycle aretherefore suggested as potent behavioral mechanisms to causepatterns of community dynamics. We emphasize that correct estimationsof interaction-mediated foraging-cycle efficiencies should beconsidered in empirical and theoretical attempts to furtherour understanding of the mechanistic link between social behaviorsand higher order processes.     

Bioremediation potential of a widespread industrial biowaste as renewable and sustainable biosorbent for synthetic dye pollution

In this study, a model synthetic azo dye (Basic red 46) bioremoval by Carpinus betulus sawdust as inexpensive, eco-friendly, and sustainable biosorbent from aqueous solution was examined in a batch biosorption system. The effective environmental parameters on the biosorption process, such as the value of pH, amount of biosorbent, initial dye concentration and contact time were optimized using classical test design. The possible dye-biosorbent interaction was determined by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The equilibrium, thermodynamic, and kinetic studies for the biosorption of Basic red 46 onto the sawdust biomass were performed. In addition, a single-stage batch dye biosorption system was also designed. The dye biosorption yield of biosorbent was significantly influenced by the change of operating variables. The experimental data were best described by the Freundlich isotherm model and both the pseudo-first-order kinetic and the pseudo-second-order kinetic models. Thermodynamic research indicated that the biosorption of dye was feasible and spontaneous. Based on the Langmuir isotherm model, the biosorbent was found to have a maximum biosorption potential higher than many other biosorbents in the literature (264.915?mg g^?1). Thus, this investigation presents a novel green option for the assessment of waste sawdust biomass as a cheap and effective biosorbent material.     

The interrelations of radiologic findings and mechanical ventilation in community acquired pneumonia patients admitted to the intensive care unit: a multicentre retrospective study

Background

Burkholderia cepacia complex (BCC) bacteria are highly virulent, typically multidrug-resistant, opportunistic pathogens in cystic fibrosis (CF) patients and other immunocompromised individuals. B. vietnamiensis is more often susceptible to aminoglycosides than other BCC species, and strains acquire aminoglycoside resistance during chronic CF infection and under tobramycin and azithromycin exposure in vitro, apparently from gain of antimicrobial efflux as determined through pump inhibition. The aims of the present study were to determine if oxidative stress could also induce aminoglycoside resistance and provide further observations in support of a role for antimicrobial efflux in aminoglycoside resistance in B. vietnamiensis.

Findings

Here we identified hydrogen peroxide as an additional aminoglycoside resistance inducing agent in B. vietnamiensis. After antibiotic and hydrogen peroxide exposure, isolates accumulated significantly less [³H] gentamicin than the susceptible isolate from which they were derived. Strains that acquired aminoglycoside resistance during infection and after exposure to tobramycin or azithromycin overexpressed a putative resistance-nodulation-division (RND) transporter gene, amrB. Missense mutations in the repressor of amrB, amrR, were identified in isolates that acquired resistance during infection, and not in those generated in vitro.

Conclusions

These data identify oxidative stress as an inducer of aminoglycoside resistance in B. vietnamiensis and further suggest that active efflux via a RND efflux system impairs aminoglycoside accumulation in clinical B. vietnamiensis strains that have acquired aminoglycoside resistance, and in those exposed to tobramycin and azithromycin, but not hydrogen peroxide, in vitro. Furthermore, the repressor AmrR is likely just one regulator of the putative AmrAB-OprM efflux system in B. vietnamiensis.     

Olive mill wastewater treatment in single-chamber air-cathode microbial fuel cells

Olive mill wastewaters create significant environmental issues in olive-processing countries. One of the most hazardous groups of pollutants in these wastewaters is phenolic compounds. Here, olive mill wastewater was used as substrate and treated in single-chamber air-cathode microbial fuel cells. Olive mill wastewater yielded a maximum voltage of 381 mV on an external resistance of 1 kΩ. Notable decreases in the contents of 3,4-dihydroxybenzoic acid, tyrosol, gallic acid and p-coumaric acid were detected. Chemical oxygen demand removal rates were 65 % while removal of total phenolics by the process was lower (49 %). Microbial community analysis during the olive mill wastewater treating MFC has shown that both exoelectrogenic and phenol-degrading microorganisms have been enriched during the operation. Brevundimonas-, Sphingomonas- and Novosphingobium-related phylotypes were enriched on the anode biofilm, while Alphaproteobacteria and Bacteriodetes dominated the cathode biofilm. As one of the novel studies, it has been demonstrated that recalcitrant olive mill wastewaters could be treated and utilized for power generation in microbial fuel cells.     

First and second generation γ-secretase modulators (GSMs) modulate amyloid-β (Aβ) peptide production through different mechanisms

γ-Secretase-mediated cleavage of amyloid precursor protein (APP) results in the production of Alzheimer disease-related amyloid-β (Aβ) peptides. The Aβ42 peptide in particular plays a pivotal role in Alzheimer disease pathogenesis and represents a major drug target. Several γ-secretase modulators (GSMs), such as the nonsteroidal anti-inflammatory drugs (R)-flurbiprofen and sulindac sulfide, have been suggested to modulate the Alzheimer-related Aβ production by targeting the APP. Here, we describe novel GSMs that are selective for Aβ modulation and do not impair processing of Notch, EphB2, or EphA4. The GSMs modulate Aβ both in cell and cell-free systems as well as lower amyloidogenic Aβ42 levels in the mouse brain. Both radioligand binding and cellular cross-competition experiments reveal a competitive relationship between the AstraZeneca (AZ) GSMs and the established second generation GSM, E2012, but a noncompetitive interaction between AZ GSMs and the first generation GSMs (R)-flurbiprofen and sulindac sulfide. The binding of a (3)H-labeled AZ GSM analog does not co-localize with APP but overlaps anatomically with a γ-secretase targeting inhibitor in rodent brains. Combined, these data provide compelling evidence of a growing class of in vivo active GSMs, which are selective for Aβ modulation and have a different mechanism of action compared with the original class of GSMs described.     

Bioelement Status with Oral Administration of Fish Oil Methyl Ester and Diesel Fuel in Male Rats

This paper is a study on the effects on the amounts of trace elements in case of possible repeat accidental or environmental exposure with fish oil biodiesel. For this purpose, 35 male Wistar albino rats were used in the study. Rats were divided into five groups. The first group was determined as the control group. The rats in this group were gavaged orally with 250?mg/kg sunflower oil. The rats in the second and third groups were administered by oral gavage of 250?mg/kg (D1) and 500?mg/kg (D2) diesel fuel mixed with equal amounts of sunflower oil, respectively. The rats in the fourth group were administered by oral gavage of 250?mg/kg fish oil biodiesel (F1) and the rats in the fifth group were administered by oral gavage of 500?mg/kg fish oil biodiesel (F2), both mixed with equal amounts of sunflower oil. At the end of the study, bioelement concentrations in the serum and the kidney, lung, and liver tissues were measured using inductively coupled plasma-optical emission spectroscopy. It was observed that serum Ca, Mg, and Sr concentrations were significantly (p?相似文献   

Expression of Helix pomatia lectin binding glycoproteins in women with breast cancer in relationship to their blood group phenotypes

Aberrant glycosylation occurs in essentially all types of human cancers. A difference in glycopattern of proteins will result in a change of function of the proteins. The lectin from Helix pomatia (HPA) recognizes N-acetylgalactosaminylated glycoproteins and very consistent results over the increased binding of HPA in tissue sections are associated with metastasis progression and poor patient prognosis in a range of human adenocarcinomas. The induced modification of protein function after changed glycosylation is unknown, and as a part in characterizing the glycoproteins carrying the specific carbohydrates, we analyzed the major HPA binding proteins in sera from healthy women, women with primary breast cancer with no metastasis (bcmet-), and women with metastasizing breast cancer (bcmet+) using lectin affinity chromatography and lectin blotting. The binding ligands were further identified using mass spectrometry (MALDI-TOF MS) to confirm the captured glycoproteins. The major HPA binding proteins in serum were found to be IgA1, complement factor C3, von Willebrand factor (vWF), alpha-2-macroglobulin and IgM. This set of antigens is a panel of candidates for useful HPA related biomarkers in sera, but our results also emphasize the fact that the blood group phenotypes are of most importance when using the lectin HPA in recognition of cancer biomarkers in sera and plasma. The results emphasize that interpretation of an individual change in the glycosylation pattern of a specific tumor marker always needs to be analyzed in its right context. This study shows that the blood group phenotypes can have a major impact on the results when analyzing HPA lectin binding.