Effects of riparian plant diversity loss on aquatic microbial decomposers become more pronounced at longer times

We examined the potential long-term impacts of riparian plant diversity loss on diversity and activity of aquatic microbial decomposers. Microbial assemblages were obtained in a mixed-forest stream by immersion of mesh bags contain-ing three leaf species (alder, oak and eucalyptus), commonly found in riparian corridors of Iberian streams. Simulation of species loss was done in microcosms by including a set of all leaf species, retrieved from the stream, and non-colonized leaves of three, two or one leaf species. Leaves were renewed every month throughout six months, and microbial inoculum was ensured by a set of colonized leaves from the previous month. Microbial diversity, leaf mass loss and fungal biomass were assessed at the second and sixth months after plant species loss. Molecular diversity of fungi and bacteria, as the total number of operational taxonomic units per leaf diversity treatment, decreased with leaf diversity loss. Fungal biomass tended to decrease linearly with leaf species loss on oak and eucalyptus, suggesting more pronounced effects of leaf diver-sity on lower quality leaves. Decomposition of alder and eucalyptus leaves was affected by leaf species identity, mainly after longer times following diversity loss. Leaf decomposi-tion of alder decreased when mixed with eucalyptus, while decomposition of eucalyptus decreased in mixtures with oak. Results suggest that the effects of leaf diversity on microbial decomposers depended on leaf species number and also on which species were lost from the system, especially after longer times. This may have implications for the management of riparian forests to maintain stream ecosystem functioning.FEDER-POFC-COMPETE and the Portuguese Foundation for Science and Technology supported this study (PEst-C/ BIA/UI4050/2011, PTDC/AAC-AMB/113746/2009 and PTDC/AAC-AMB/117068/2010), S. Duarte (SFRH/BPD/47574/2008) and I. Fernandes (SFRH/BD/42215/2007)

Behavioral responses to injury and death in wild Barbary macaques (Macaca sylvanus)

The wounding or death of a conspecific has been shown to elicit varied behavioral responses throughout thanatology. Recently, a number of reports have presented contentious evidence of epimeletic behavior towards the dying and dead among non-human animals, a behavioral trait previously considered uniquely human. Here, we report on the behavioral responses of Barbary macaques, a social, non-human primate, to the deaths of four group members (one high-ranking adult female, one high-ranking adult male, one juvenile male, and one female infant), all caused by road traffic accidents. Responses appeared to vary based on the nature of the death (protracted or instant) and the age class of the deceased. Responses included several behaviors with potential adaptive explanations or consequences. These included exploration, caretaking (guarding, carrying, and grooming), and proximity to wounded individuals or corpses, and immediate as well as longer-lasting distress behaviors from other group members following death, all of which have been reported in other non-human primate species. These observations add to a growing body of comparative evolutionary analysis of primate thanatology and help to highlight the multifaceted impacts of human-induced fatalities on an endangered and socially complex primate. © 2016, Japan Monkey Centre and Springer Japan

Vaccine delivery by penetratin: mechanism of antigen presentation by dendritic cells

Cell-penetrating peptides (CPP) or membrane-translocating peptides such as penetratin from Antennapedia homeodomain or TAT from human immunodeficiency virus are useful vectors for the delivery of protein antigens or their cytotoxic (Tc) or helper (Th) T cell epitopes to antigen-presenting cells. Mice immunized with CPP containing immunogens elicit antigen-specific Tc and/or Th responses and could be protected from tumor challenges. In the present paper, we investigate the mechanism of class I and class II antigen presentation of ovalbumin covalently linked to penetratin (AntpOVA) by bone marrow-derived dendritic cells with the use of biochemical inhibitors of various pathways of antigen processing and presentation. Results from our study suggested that uptake of AntpOVA is via a combination of energy-independent (membrane fusion) and energy-dependent pathways (endocytosis). Once internalized by either mechanism, multiple tap-dependent or independent antigen presentation pathways are accessed while not completely dependent on proteasomal processing but involving proteolytic trimming in the ER and Golgi compartments. Our study provides an understanding on the mechanism of antigen presentation mediated by CPP and leads to greater insights into future development of vaccine formulations

The proinflammatory cytokine IL-36γ is a global discriminator of harmless microbes and invasive pathogens within epithelial tissues

Epithelial tissues represent vital interfaces between organisms and their environment. As they are constantly exposed to harmful pathogens, innocuous commensals, and environmental microbes, it is essential they sense and elicit appropriate responses toward these different types of microbes. Here, we demonstrate that the epithelial cytokine interleukin-36γ (IL-36γ) acts as a global discriminator of pathogenic and harmless microbes via cell damage and proteolytic activation. We show that intracellular pro-IL-36γ is upregulated by both fungal and bacterial epithelial microbes; yet, it is only liberated from cells, and subsequently processed to its mature, potent, proinflammatory form, by pathogen-mediated cell damage and pathogen-derived proteases. This work demonstrates that IL-36γ senses pathogen-induced cell damage and proteolytic activity and is a key initiator of immune responses and pathological inflammation within epithelial tissues. As an apically located epithelial proinflammatory cytokine, we therefore propose that IL-36γ is critical as the initial discriminator of harmless microbes and invasive pathogens within epithelial tissues

Slow GABAA mediated synaptic transmission in rat visual cortex

<p>Abstract</p> <p>Background</p> <p>Previous reports of inhibition in the neocortex suggest that inhibition is mediated predominantly through GABA_Areceptors exhibiting fast kinetics. Within the hippocampus, it has been shown that GABA_Aresponses can take the form of either fast or slow response kinetics. Our findings indicate, for the first time, that the neocortex displays synaptic responses with slow GABA_Areceptor mediated inhibitory postsynaptic currents (IPSCs). These IPSCs are kinetically and pharmacologically similar to responses found in the hippocampus, although the anatomical specificity of evoked responses is unique from hippocampus. Spontaneous slow GABA_AIPSCs were recorded from both pyramidal and inhibitory neurons in rat visual cortex.</p> <p>Results</p> <p>GABA_Aslow IPSCs were significantly different from fast responses with respect to rise times and decay time constants, but not amplitudes. Spontaneously occurring GABA_Aslow IPSCs were nearly 100 times less frequent than fast sIPSCs and both were completely abolished by the chloride channel blocker, picrotoxin. The GABA_Asubunit-specific antagonist, furosemide, depressed spontaneous and evoked GABA_Afast IPSCs, but not slow GABA_A-mediated IPSCs. Anatomical specificity was evident using minimal stimulation: IPSCs with slow kinetics were evoked predominantly through stimulation of layer 1/2 apical dendritic zones of layer 4 pyramidal neurons and across their basal dendrites, while GABA_Afast IPSCs were evoked through stimulation throughout the dendritic arborization. Many evoked IPSCs were also composed of a combination of fast and slow IPSC components.</p> <p>Conclusion</p> <p>GABA_Aslow IPSCs displayed durations that were approximately 4 fold longer than typical GABA_Afast IPSCs, but shorter than GABA_B-mediated inhibition. The anatomical and pharmacological specificity of evoked slow IPSCs suggests a unique origin of synaptic input. Incorporating GABA_Aslow IPSCs into computational models of cortical function will help improve our understanding of cortical information processing.</p

Analysis of a sprint ski race and associated laboratory determinants of world-class performance

This investigation was designed to analyze the time-trial (STT) in an international cross-country skiing sprint skating competition for (1) overall STT performance and relative contributions of time spent in different sections of terrain, (2) work rate and kinematics on uphill terrain, and (3) relationships to physiological and kinematic parameters while treadmill roller ski skating. Total time and times in nine different sections of terrain by 12 world-class male sprint skiers were determined, along with work rate and kinematics for one specific uphill section. In addition, peak oxygen uptake (VO2peak), gross efficiency (GE), peak speed (Vpeak), and kinematics in skating were measured. Times on the last two uphill and two final flat sections were correlated to overall STT performance (r = ~−0.80, P < 0.001). For the selected uphill section, speed was correlated to cycle length (r = −0.75, P < 0.01) and the estimated work rate was approximately 160% of peak aerobic power. VO2peak, GE, Vpeak, and peak cycle length were all correlated to STT performance (r = ~−0.85, P < 0.001). More specifically, VO2peak and GE were correlated to the last two uphill and two final flat section times, whereas Vpeak and peak cycle length were correlated to times in all uphill, flat, and curved sections except for the initial section (r = ~−0.80, P < 0.01). Performances on uphill and flat terrain in the latter part were the most significant determinants of overall STT performance. Peak oxygen uptake, efficiency, peak speed, and peak cycle length were strongly correlated to overall STT performance, as well as to performance in different sections of the race

Differential surface density and modulatory effects of presynaptic GABAB receptors in hippocampal cholecystokinin and parvalbumin basket cells

The perisomatic domain of cortical neurons is under the control of two major GABAergic inhibitory interneuron types: regular-spiking cholecystokinin (CCK) basket cells (BCs) and fast-spiking parvalbumin (PV) BCs. CCK and PV BCs are different not only in their intrinsic physiological, anatomical and molecular characteristics, but also in their presynaptic modulation of their synaptic output. Most GABAergic terminals are known to contain GABAB receptors (GABABR), but their role in presynaptic inhibition and surface expression have not been comparatively characterized in the two BC types. To address this, we performed whole-cell recordings from CCK and PV BCs and postsynaptic pyramidal cells (PCs), as well as freeze-fracture replica-based quantitative immunogold electron microscopy of their synapses in the rat hippocampal CA1 area. Our results demonstrate that while both CCK and PV BCs contain functional presynaptic GABABRs, their modulatory effects and relative abundance are markedly different at these two synapses: GABA release is dramatically inhibited by the agonist baclofen at CCK BC synapses, whereas a moderate reduction in inhibitory transmission is observed at PV BC synapses. Furthermore, GABABR activation has divergent effects on synaptic dynamics: paired-pulse depression (PPD) is enhanced at CCK BC synapses, but abolished at PV BC synapses. Consistent with the quantitative differences in presynaptic inhibition, virtually all CCK BC terminals were found to contain GABABRs at high densities, but only 40% of PV BC axon terminals contain GABABRs at detectable levels. These findings add to an increasing list of differences between these two interneuron types, with implications for their network functions

(+)-Rutamarin as a Dual Inducer of Both GLUT4 Translocation and Expression Efficiently Ameliorates Glucose Homeostasis in Insulin-Resistant Mice

Glucose transporter 4 (GLUT4) is a principal glucose transporter in response to insulin, and impaired translocation or decreased expression of GLUT4 is believed to be one of the major pathological features of type 2 diabetes mellitus (T2DM). Therefore, induction of GLUT4 translocation or/and expression is a promising strategy for anti-T2DM drug discovery. Here we report that the natural product (+)-Rutamarin (Rut) functions as an efficient dual inducer on both insulin-induced GLUT4 translocation and expression. Rut-treated 3T3-L1 adipocytes exhibit efficiently enhanced insulin-induced glucose uptake, while diet-induced obese (DIO) mice based assays further confirm the Rut-induced improvement of glucose homeostasis and insulin sensitivity in vivo. Subsequent investigation of Rut acting targets indicates that as a specific protein tyrosine phosphatase 1B (PTP1B) inhibitor Rut induces basal GLUT4 translocation to some extent and largely enhances insulin-induced GLUT4 translocation through PI3 kinase-AKT/PKB pathway, while as an agonist of retinoid X receptor α (RXRα), Rut potently increases GLUT4 expression. Furthermore, by using molecular modeling and crystallographic approaches, the possible binding modes of Rut to these two targets have been also determined at atomic levels. All our results have thus highlighted the potential of Rut as both a valuable lead compound for anti-T2DM drug discovery and a promising chemical probe for GLUT4 associated pathways exploration

Trade-Off between Toxicity and Signal Detection Orchestrated by Frequency- and Density-Dependent Genes

Behaviors in insects are partly highly efficient Bayesian processes that fulfill exploratory tasks ending with the colonization of new ecological niches. The foraging (for) gene in Drosophila encodes a cGMP-dependent protein kinase (PKG). It has been extensively described as a frequency-dependent gene and its transcripts are differentially expressed between individuals, reflecting the population density context. Some for transcripts, when expressed in a population at high density for many generations, concomitantly trigger strong dispersive behavior associated with foraging activity. Moreover, genotype-by-environment interaction (GEI) analysis has highlighted a dormant role of for in energetic metabolism in a food deprivation context. In our current report, we show that alleles of for encoding different cGMP-dependent kinase isoforms influence the oxidation of aldehyde groups of aromatic molecules emitted by plants via Aldh-III and a phosphorylatable adaptor. The enhanced efficiency of oxidation of aldehyde odorants into carboxyl groups by the action of for lessens their action and toxicity, which should facilitate exploration and guidance in a complex odor environment. Our present data provide evidence that optimal foraging performance requires the fast metabolism of volatile compounds emitted by plants to avoid neurosensory saturation and that the frequency-dependent genes that trigger dispersion influence these processes

A Project Portfolio Management Approach to Tacklingthe Exploration/Exploitation Trade-off

Organizational ambidexterity (OA) is an essen-tial capability for surviving in dynamic business environ-ments that advocates the simultaneous engagement inexploration and exploitation. Over the last decades,knowledge on OA has substantially matured, coveringinsights into antecedents, outcomes, and moderators of OA.However, there is little prescriptive knowledge that offersguidance on how to put OA into practice and to tackle thetrade-off between exploration and exploitation. To addressthis gap, the authors adopt the design science researchparadigm and propose an economic decision model asartifact. The decision model assists organizations inselecting and scheduling exploration and exploitation pro-jects to become ambidextrous in an economically reason-able manner. As for justificatory knowledge, the decisionmodel draws from prescriptive knowledge on projectportfolio management and value-based management, andfrom descriptive knowledge related to OA to structure thefield of action. To evaluate the decision model, its designspecification is discussed against theory-backed designobjectives and with industry experts. The paper alsoinstantiates the decision model as a software prototype andapplies the prototype to a case based on real-world data