Synchronous dynamics of zooplankton competitors prevail in temperate lake ecosystems

Although competing species are expected to exhibit compensatory dynamics (negative temporal covariation), empirical work has demonstrated that competitive communities often exhibit synchronous dynamics (positive temporal covariation). This has led to the suggestion that environmental forcing dominates species dynamics; however, synchronous and compensatory dynamics may appear at different length scales and/or at different times, making it challenging to identify their relative importance. We compiled 58 long-term datasets of zooplankton abundance in north-temperate and sub-tropical lakes and used wavelet analysis to quantify general patterns in the times and scales at which synchronous/compensatory dynamics dominated zooplankton communities in different regions and across the entire dataset. Synchronous dynamics were far more prevalent at all scales and times and were ubiquitous at the annual scale. Although we found compensatory dynamics in approximately 14% of all combinations of time period/scale/lake, there were no consistent scales or time periods during which compensatory dynamics were apparent across different regions. Our results suggest that the processes driving compensatory dynamics may be local in their extent, while those generating synchronous dynamics operate at much larger scales. This highlights an important gap in our understanding of the interaction between environmental and biotic forces that structure communities

Phosphorylation of the actin binding protein Drebrin at S647 and is regulated by neuronal activity and PTEN

Defects in actin dynamics affect activity-dependent modulation of synaptic transmission and neuronal plasticity, and can cause cognitive impairment. A salient candidate actin-binding protein linking synaptic dysfunction to cognitive deficits is Drebrin (DBN). However, the specific mode of how DBN is regulated at the central synapse is largely unknown. In this study we identify and characterize the interaction of the PTEN tumor suppressor with DBN. Our results demonstrate that PTEN binds DBN and that this interaction results in the dephosphorylation of a site present in the DBN C-terminus - serine 647. PTEN and pS647-DBN segregate into distinct and complimentary compartments in neurons, supporting the idea that PTEN negatively regulates DBN phosphorylation at this site. We further demonstrate that neuronal activity increases phosphorylation of DBN at S647 in hippocampal neurons in vitro and in ex vivo hippocampus slices exhibiting seizure activity, potentially by inducing rapid dissociation of the PTEN:DBN complex. Our results identify a novel mechanism by which PTEN is required to maintain DBN phosphorylation at dynamic range and signifies an unusual regulation of an actin-binding protein linked to cognitive decline and degenerative conditions at the CNS synapse

EFFICACY, SAFETY, AND TOLERABILITY OF MIRABEGRON IN PATIENTS AGED ≥65 YR WITH OVERACTIVE BLADDER WET: A PHASE IV, DOUBLE-BLIND, RANDOMISED, PLACEBOCONTROLLED STUDY (PILLAR)

Pozadina: Većina bolesnika s prekomjerno aktivnim mokraćnim mjehurom (PAMM) starija je od 65 godina. Dosad nije bilo prospektivnih ispitivanja kojima bi se ocijenila djelotvornost liječenja agonistom β3-adrenoreceptora mirabegronom u ovoj specifi čnoj dobnoj skupini. Cilj: Ispitivanje faze IV u kojem se uspoređuju mirabegron u fl eksibilnoj dozi i placebo u starijih bolesnika s PAMM om i urgentnom inkontinencijom. Dizajn, uvjeti i sudionici: Bolesnici iz lokalne zajednice koji imaju ≥ 65 godina i PAMM u trajanju od ≥ 3 mjeseca. Intervencija: Nakon 2 tjednog uvodnog razdoblja tijekom kojeg se primjenjivao placebo bolesnici s jednom ili više epizoda inkontinencije, tri ili više epizoda urgencije i prosječno osam ili više mokrenja tijekom 24 h bili su randomizirani u omjeru 1:1 za dvostruko zaslijepljenu primjenu 25 mg mirabegrona ili odgovarajuće formulacije placeba na dan tijekom 12 tjedana. Nakon 4. ili 8. tjedna doza se prema odluci bolesnika i ispitivača mogla povećati na 50 mg mirabegrona/odgovarajuće formulacije placeba na dan. Mjere ishoda i statistička analiza: Primarne mjere ishoda: promjena srednjeg broja mokrenja tijekom 24 h i srednjeg broja epizoda inkontinencije tijekom 24 h od početka ispitivanja do završetka liječenja. Sekundarne mjere ishoda: promjena srednjeg izmokrenog volumena nakon mokrenja, srednjeg broja epizoda urgencije tijekom 24 h i srednjeg broja epizoda urgentne inkontinencije tijekom 24 h od početka ispitivanja do završetka liječenja. Za ocjenu srednjeg broja mokrenja tijekom 24 h, srednjeg izmokrenog volumena nakon mokrenju i srednjeg broja epizoda urgencije tijekom 24 h koristila se analiza kovarijance (ANCOVA). Za ocjenu srednjeg broja epizoda inkontinencije tijekom 24 h i srednjeg broja epizoda urgentne inkontinencije tijekom 24 h koristila se stratifi cirana rang ANCOVA. Rezultati i ograničenja: Uz mirabegron su opažena statistički značajna poboljšanja u odnosu na placebo s obzirom na promjenu srednjeg broja mokrenja tijekom 24 h, srednjeg broja epizoda inkontinencije tijekom 24 h, srednjeg izmokrenog volumena nakon mokrenja, srednjeg broja epizoda urgencije tijekom 24 h i srednjeg broja epizoda urgentne inkontinencije tijekom 24 h od početka ispitivanja do završetka liječenja. Sigurnost i podnošljivost odgovarale su poznatom sigurnosnom profi lu mirabegrona. Zaključci: Potvrđene su djelotvornost, sigurnost i podnošljivost mirabegrona tijekom 12 tjedana u bolesnika s PAMM om i inkontinencijom u dobi od ≥ 65 godina. Sažetak za bolesnike: Ispitivali smo učinak mirabegrona u usporedbi s placebom u osoba u dobi od 65 ili više godina s prekomjerno aktivnim mokraćnim mjehurom i inkontinencijom. Mirabegron je ublažio simptome prekomjerno aktivnog mokraćnog mjehura u usporedbi s placebom. Opažene nuspojave bile su slične poznatim nuspojavama mirabegrona.Background: The majority of patients with overactive bladder (OAB) are aged >65 yr. There has been no prospectively designed study assessing treatment effi cacy with the b3-adrenoreceptor agonist, mirabegron, specifi cally in this age group. Objective: A phase IV study comparing fl exibly dosed mirabegron versus placebo in elderly patients with OAB and urgency incontinence. Design, setting, and participants: Community-dwelling patients aged ≥65 yr with OAB for ≥3 mo. Intervention: Following a 2-wk placebo run in, patients with one or more incontinence episodes, three or more urgency episodes, and an average of eight or more micturitions/ 24 h were randomised 1:1 to double-blind 25 mg/d mirabegron or matched placebo, for 12 wk. After week 4 or 8, the dose could be increased to 50 mg/d mirabegron/matched placebo based on patient and investigator discretion. Outcome measurements and statistical analysis: Coprimary endpoints: change from baseline to end of treatment (EOT) in the mean numbers of micturitions/24 h and incontinence episodes/24 h. Secondary endpoints: change from baseline to EOT in the mean volume voided/micturition, mean number of urgency episodes/24 h, and mean number of urgency incontinence episodes/24 h. Analysis of covariance (ANCOVA) was used for the mean number of micturitions/24 h, mean volume voided/micturition, and mean number of urgency episodes/24 h. Stratifi ed rank ANCOVA was used for the mean numbers of incontinence episodes/24 h and urgency incontinence episodes/24 h. Results and limitations: Statistically signifi cant improvements were observed for mirabegron versus placebo in change from baseline to EOT in the mean number of micturitions/24 h, mean number of incontinence episodes/24 h, mean volume voided/micturition, mean number of urgency episodes/24 h, and mean number of urgency incontinence episodes/24 h. Safety and tolerability were consistent with the known mirabegron safety profi le. Conclusions: Mirabegron effi cacy, safety, and tolerability over 12 wk were confi rmed in patients aged ≥65 yr with OAB and incontinence

Comprehensive Evaluation of the 5XFAD Mouse Model for Preclinical Testing Applications: A MODEL-AD Study.

The ability to investigate therapeutic interventions in animal models of neurodegenerative diseases depends on extensive characterization of the model(s) being used. There are numerous models that have been generated to study Alzheimer\u27s disease (AD) and the underlying pathogenesis of the disease. While transgenic models have been instrumental in understanding AD mechanisms and risk factors, they are limited in the degree of characteristics displayed in comparison with AD in humans, and the full spectrum of AD effects has yet to be recapitulated in a single mouse model. The Model Organism Development and Evaluation for Late-Onset Alzheimer\u27s Disease (MODEL-AD) consortium was assembled by the National Institute on Aging (NIA) to develop more robust animal models of AD with increased relevance to human disease, standardize the characterization of AD mouse models, improve preclinical testing in animals, and establish clinically relevant AD biomarkers, among other aims toward enhancing the translational value of AD models in clinical drug design and treatment development. Here we have conducted a detailed characterization of the 5XFAD mouse, including transcriptomics, electroencephalogram

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey : baryon acoustic oscillations in the Data Releases 10 and 11 Galaxy samples

We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations (BAO) in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey, which is part of the Sloan Digital Sky Survey III. Our results come from the Data Release 11 (DR11) sample, containing nearly one million galaxies and covering approximately 8500 square degrees and the redshift range 0.2 < z < 0.7. We also compare these results with those from the publicly released DR9 and DR10 samples. Assuming a concordance Λ cold dark matter (ΛCDM) cosmological model, the DR11 sample covers a volume of 13 Gpc3 and is the largest region of the Universe ever surveyed at this density. We measure the correlation function and power spectrum, including density-field reconstruction of the BAO feature. The acoustic features are detected at a significance of over 7σ in both the correlation function and power spectrum. Fitting for the position of the acoustic features measures the distance relative to the sound horizon at the drag epoch, rd, which has a value of rd,fid = 149.28 Mpc in our fiducial cosmology. We find DV = (1264 ± 25 Mpc)(rd/rd,fid) at z = 0.32 and DV = (2056 ± 20 Mpc)(rd/rd,fid) at z = 0.57. At 1.0 per cent, this latter measure is the most precise distance constraint ever obtained from a galaxy survey. Separating the clustering along and transverse to the line of sight yields measurements at z = 0.57 of DA = (1421 ± 20 Mpc)(rd/rd,fid) and H = (96.8 ± 3.4 km s−1 Mpc−1)(rd,fid/rd). Our measurements of the distance scale are in good agreement with previous BAO measurements and with the predictions from cosmic microwave background data for a spatially flat CDM model with a cosmological constant.Publisher PDFPeer reviewe

A molecular link between cell wall biosynthesis, translation fidelity, and stringent response in Streptococcus pneumoniae

Survival in the human host requires bacteria to respond to unfavorable conditions. In the important Gram-positive pathogen Streptococcus pneumoniae, cell wall biosynthesis proteins MurM and MurN are tRNA-dependent amino acyl transferases which lead to the production of branched muropeptides. We demonstrate that wild-type cells experience optimal growth under mildly acidic stressed conditions, but ΔmurMN strain displays growth arrest and extensive lysis. Furthermore, these stress conditions compromise the efficiency with which alanyl-tRNAAla synthetase can avoid noncognate mischarging of tRNAAla with serine, which is toxic to cells. The observed growth defects are rescued by inhibition of the stringent response pathway or by overexpression of the editing domain of alanyl-tRNAAla synthetase that enables detoxification of tRNA misacylation. Furthermore, MurM can incorporate seryl groups from mischarged Seryl-tRNAAlaUGC into cell wall precursors with exquisite specificity. We conclude that MurM contributes to the fidelity of translation control and modulates the stress response by decreasing the pool of mischarged tRNAs. Finally, we show that enhanced lysis of ΔmurMN pneumococci is caused by LytA, and the murMN operon influences macrophage phagocytosis in a LytA-dependent manner. Thus, MurMN attenuates stress responses with consequences for host–pathogen interactions. Our data suggest a causal link between misaminoacylated tRNA accumulation and activation of the stringent response. In order to prevent potential corruption of translation, consumption of seryl-tRNAAla by MurM may represent a first line of defense. When this mechanism is overwhelmed or absent (ΔmurMN), the stringent response shuts down translation to avoid toxic generation of mistranslated/misfolded protein

Uncovering Disease Mechanisms in a Novel Mouse Model Expressing Humanized APOEε4 and Trem2*R47H.

Late-onset Alzheimer\u27s disease (AD; LOAD) is the most common human neurodegenerative disease, however, the availability and efficacy of disease-modifying interventions is severely lacking. Despite exceptional efforts to understand disease progression via legacy amyloidogenic transgene mouse models, focus on disease translation with innovative mouse strains that better model the complexity of human AD is required to accelerate the development of future treatment modalities. LOAD within the human population is a polygenic and environmentally influenced disease with many risk factors acting in concert to produce disease processes parallel to those often muted by the early and aggressive aggregate formation in popular mouse strains. In addition to extracellular deposits of amyloid plaques and inclusions of the microtubule-associated protein tau, AD is also defined by synaptic/neuronal loss, vascular deficits, and neuroinflammation. These underlying processes need to be better defined, how the disease progresses with age, and compared to human-relevant outcomes. To create more translatable mouse models, MODEL-AD (Model Organism Development and Evaluation for Late-onset AD) groups are identifying and integrating disease-relevant, humanized gene sequences from public databases beginning with APOEε4 and Trem2*R47H, two of the most powerful risk factors present in human LOAD populations. Mice expressing endogenous, humanized APOEε4 and Trem2*R47H gene sequences were extensively aged and assayed using a multi-disciplined phenotyping approach associated with and relative to human AD pathology. Robust analytical pipelines measured behavioral, transcriptomic, metabolic, and neuropathological phenotypes in cross-sectional cohorts for progression of disease hallmarks at all life stages. In vivo PET/MRI neuroimaging revealed regional alterations in glycolytic metabolism and vascular perfusion. Transcriptional profiling by RNA-Seq of brain hemispheres identified sex and age as the main sources of variation between genotypes including age-specific enrichment of AD-related processes. Similarly, age was the strongest determinant of behavioral change. In the absence of mouse amyloid plaque formation, many of the hallmarks of AD were not observed in this strain. However, as a sensitized baseline model with many additional alleles and environmental modifications already appended, the dataset from this initial MODEL-AD strain serves an important role in establishing the individual effects and interaction between two strong genetic risk factors for LOAD in a mouse host

Antigen Extraction and B Cell Activation Enable Identification of Rare Membrane Antigen Specific Human B Cells

Determining antigen specificity is vital for understanding B cell biology and for producing human monoclonal antibodies. We describe here a powerful method for identifying B cells that recognize membrane antigens expressed on cells. The technique depends on two characteristics of the interaction between a B cell and an antigen-expressing cell: antigen-receptor-mediated extraction of antigen from the membrane of the target cell, and B cell activation. We developed the method using influenza hemagglutinin as a model viral membrane antigen, and tested it using acetylcholine receptor (AChR) as a model membrane autoantigen. The technique involves co-culturing B cells with adherent, bioorthogonally labeled cells expressing GFP-tagged antigen, and sorting GFP-capturing, newly activated B cells. Hemagglutinin-specific B cells isolated this way from vaccinated human donors expressed elevated CD20, CD27, CD71, and CD11c, and reduced CD21, and their secreted antibodies blocked hemagglutination and neutralized viral infection. Antibodies cloned from AChR-capturing B cells derived from patients with myasthenia gravis bound specifically to the receptor on cell membrane. The approach is sensitive enough to detect antigen-specific B cells at steady state, and can be adapted for any membrane antigen

Comprehensive Evaluation of the 5XFAD Mouse Model for Preclinical Testing Applications: A MODEL-AD Study.

The ability to investigate therapeutic interventions in animal models of neurodegenerative diseases depends on extensive characterization of the model(s) being used. There are numerous models that have been generated to study Alzheimer\u27s disease (AD) and the underlying pathogenesis of the disease. While transgenic models have been instrumental in understanding AD mechanisms and risk factors, they are limited in the degree of characteristics displayed in comparison with AD in humans, and the full spectrum of AD effects has yet to be recapitulated in a single mouse model. The Model Organism Development and Evaluation for Late-Onset Alzheimer\u27s Disease (MODEL-AD) consortium was assembled by the National Institute on Aging (NIA) to develop more robust animal models of AD with increased relevance to human disease, standardize the characterization of AD mouse models, improve preclinical testing in animals, and establish clinically relevant AD biomarkers, among other aims toward enhancing the translational value of AD models in clinical drug design and treatment development. Here we have conducted a detailed characterization of the 5XFAD mouse, including transcriptomics, electroencephalogram