9,694 results match your criteria: "Department of Biology McGill University Montréal Québec Canada.[Affiliation]"

For long-lived species with biparental care, coordination and compatibility in the foraging behavior of breeding mates may be crucial to successfully raise offspring. While high foraging success is clearly important to reproductive success, it might be equally important that the mate has a complementary foraging strategy. We test whether breeding partners have similar or dissimilar foraging strategies in a species where both partners share breeding responsibilities and exhibit high mate fidelity (thick-billed murre; ).

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Background: Millions worldwide are exposed to elevated levels of arsenic that significantly increase their risk of developing atherosclerosis, a pathology primarily driven by immune cells. While the impact of arsenic on immune cell populations in atherosclerotic plaques has been broadly characterized, cellular heterogeneity is a substantial barrier to in-depth examinations of the cellular dynamics for varying immune cell populations.

Objectives: This study aimed to conduct single-cell multi-omics profiling of atherosclerotic plaques in apolipoprotein E knockout () mice to elucidate transcriptomic and epigenetic changes in immune cells induced by arsenic exposure.

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The Lepidopteran pest Trichoplusia ni and the parasitoid wasp Trichogramma brassicae represent a fascinating biological system, important for sustainable agricultural practices but challenging to observe. We present a nondestructive method based on micro-CT scanning technology (CT: computed tomography) for visualizing the internal parts of caterpillar embryos and of emerging parasitoids from infected eggs. Traditional methods of microscopic observation of the opaque egg contents require staining or dissection.

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Bipolar disorder is a leading contributor to the global burden of disease. Despite high heritability (60-80%), the majority of the underlying genetic determinants remain unknown. We analysed data from participants of European, East Asian, African American and Latino ancestries (n = 158,036 cases with bipolar disorder, 2.

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Numerous studies support the role of dopamine in modulating aggression, but the exact neural mechanisms remain elusive. Here we show that dopaminergic cells in the ventral tegmental area (VTA) can bidirectionally modulate aggression in male mice in an experience-dependent manner. Although VTA dopaminergic cells strongly influence aggression in novice aggressors, they become ineffective in expert aggressors.

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Depressive Symptoms and Amyloid Pathology.

JAMA Psychiatry

January 2025

Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.

Importance: Depressive symptoms are associated with cognitive decline in older individuals. Uncertainty about underlying mechanisms hampers diagnostic and therapeutic efforts. This large-scale study aimed to elucidate the association between depressive symptoms and amyloid pathology.

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Arctic coasts constitute the critical interface between land and sea, and are subject to rapid changes caused by a warming climate. Current trends throughout the Arctic show increasing erosion trends, while other parts of the coast are experiencing prograding trends. Until now, a vast majority of our knowledge of Arctic coastal evolution is confined to site-specific studies with limited geospatial representation.

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Background: Factors leading to severe COVID-19 remain partially known. New biomarkers predicting COVID-19 severity that are also causally involved in disease pathogenesis could improve patient management and contribute to the development of innovative therapies. Autophagy, a cytosolic structure degradation pathway is involved in the maintenance of cellular homeostasis, degradation of intracellular pathogens and generation of energy for immune responses.

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Single-nucleotide-resolution genomic maps of O6-methylguanine from the glioblastoma drug temozolomide.

Nucleic Acids Res

January 2025

Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, Zurich 8092, Switzerland.

Temozolomide kills cancer cells by forming O6-methylguanine (O6-MeG), which leads to cell cycle arrest and apoptosis. However, O6-MeG repair by O6-methylguanine-DNA methyltransferase (MGMT) contributes to drug resistance. Characterizing genomic profiles of O6-MeG could elucidate how O6-MeG accumulation is influenced by repair, but there are no methods to map genomic locations of O6-MeG.

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The virome, composed of viruses inhabiting diverse ecosystems, significantly influences microbial community dynamics and host health. The phenol-chloroform DNA extraction protocol for viromes, though effective, is time-intensive and requires the use of multiple toxic chemicals. This study introduces a streamlined, scalable protocol for DNA extraction using a commercially-available kit as an alternative, assessing its performance against the phenol-chloroform method across human fecal, mouse fecal, and soil samples.

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Prior studies examined Acidocin 4356's antibacterial and antivirulence effects against Pseudomonas aeruginosa, including cell membrane penetration abilities. Building on prior research, an in-vitro co-culture of human cells was established to evaluate the selectivity of Acidocin (ACD) by concurrently cultivating human cells and bacterial pathogens. This study evaluated the antibacterial effectiveness of ACD against Acinetobacter baumannii and Pseudomonas aeruginosa.

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The accurate and reliable performance of learned vocalizations (e.g., speech and birdsong) modulates the efficacy of communication in humans and songbirds.

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Biological invasions are a major threat to biodiversity, ecosystem functioning and nature's contributions to people worldwide. However, the effectiveness of invasive alien species (IAS) management measures and the progress toward achieving biodiversity targets remain uncertain due to limited and nonuniform data availability. Management success is usually assessed at a local level and documented in technical reports, often written in languages other than English, which makes such data notoriously difficult to collect at large geographic scales.

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Intercellular mitochondria transfer is an evolutionarily conserved process in which one cell delivers some of their mitochondria to another cell in the absence of cell division. This process has diverse functions depending on the cell types involved and physiological or disease context. Although mitochondria transfer was first shown to provide metabolic support to acceptor cells, recent studies have revealed diverse functions of mitochondria transfer, including, but not limited to, the maintenance of mitochondria quality of the donor cell and the regulation of tissue homeostasis and remodelling.

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Antimicrobial peptides (AMPs) are renowned for their potent bacteriostatic activity and safety, rendering them invaluable in animal husbandry, food safety, and medicine. Despite their potential, the physiological toxicity of AMPs to host cells significantly hampers their biosynthetic production. This study presents a novel approach for the biosynthesis of the antimicrobial peptide Kiadin by engineering a DAMP4-DPS-Kiadin fusion protein to mitigate host cell toxicity and achieve high-level expression.

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Myostatin is a paracrine myokine that regulates muscle mass in a variety of species, including humans. In this work, we report a functional role for myostatin as an endocrine hormone that directly promotes pituitary follicle-stimulating hormone (FSH) synthesis and thereby ovarian function in mice. Previously, this FSH-stimulating role was attributed to other members of the transforming growth factor-β family, the activins.

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RNA-specific nucleotidyltransferases (rNTrs) add nontemplated nucleotides to the 3 end of RNA. Two noncanonical rNTRs that are thought to be poly(A) polymerases (PAPs) have been identified in the mitochondria of trypanosomes - KPAP1 and KPAP2. KPAP1 is the primary polymerase that adds adenines (As) to trypanosome mitochondrial mRNA 3 tails, while KPAP2 is a non-essential putative polymerase whose role in the mitochondria is ambiguous.

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With climate and land use changes, tick-borne pathogens are expected to become more widely distributed in Canada. Pathogen spread and transmission in this region is modulated by changes in the abundance and distribution of tick and host populations. Here, we assessed the relationships between pathogens detected in and mammal hosts at sites of different levels of disease risk using data from summer field surveys in Ontario and Quebec, Canada.

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Diosmetin alleviates TNFα-induced liver inflammation by improving liver sinusoidal endothelial cell dysfunction.

Biomed Pharmacother

January 2025

Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology, Department of General Biochemistry, Gronostajowa 7, Kraków 30-387, Poland. Electronic address:

Sterile inflammation contributes to the development of many liver diseases including non-alcoholic fatty liver disease. Tumor necrosis factor alpha (TNFα) is a key cytokine driving liver inflammation primarily through pro-inflammatory activation of liver sinusoidal endothelial cells (LSEC). The knowledge of whether modulating LSEC activation can alleviate liver inflammation is scarce.

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Roles for the long non-coding RNA / in pancreatic beta cell function.

iScience

January 2025

Section of Cell Biology and Functional Genomics, Department of Medicine, Endocrinology and Metabolism, Imperial College London, London, UK.

Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of beta cell function. Here, we show that an lncRNA-transcribed antisense to Pax6, annotated as Pax6os1/PAX6-AS1, was upregulated by high glucose concentrations in human as well as murine beta cell lines and islets. Elevated expression was also observed in islets from mice on a high-fat diet and patients with type 2 diabetes.

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Cannabinoid receptor 1 (CB1) regulates synaptic transmission through presynaptic receptors in nerve terminals, and its physiological roles are of clinical relevance. The cellular sources and synaptic targets of CB1-expressing terminals in the human cerebral cortex are undefined. We demonstrate a variable laminar pattern of CB1-immunoreactive axons and electron microscopically show that CB1-positive GABAergic terminals make type-2 synapses innervating dendritic shafts (69%), dendritic spines (20%) and somata (11%) in neocortical layers 2-3.

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Non-native species have higher consumption rates than their native counterparts.

Biol Rev Camb Philos Soc

January 2025

Laboratório de Ecologia e Conservação, Departamento de Engenharia Ambiental, Universidade Federal do Paraná, Av. Cel. Francisco H. dos Santos 100, Curitiba, 81531-980, Brazil.

Non-native species can be major drivers of ecosystem alteration, especially through changes in trophic interactions. Successful non-native species have been predicted to have greater resource use efficiency relative to trophically analogous native species (the Resource Consumption Hypothesis), but rigorous evidence remains equivocal. Here, we tested this proposition quantitatively in a global meta-analysis of comparative functional response studies.

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Background: Globally, over one-third of pulmonary tuberculosis (TB) disease diagnoses are made based on clinical criteria after a negative bacteriological test result. There is limited information on the factors that determine clinicians' decisions to initiate TB treatment when initial bacteriological test results are negative.

Methods And Findings: We performed a systematic review and individual patient data meta-analysis using studies conducted between January 2010 and December 2022 (PROSPERO: CRD42022287613).

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Astrocytes critically shape whole-brain structure and function by forming extensive gap junctional networks that intimately and actively interact with neurons. Despite their importance, existing computational models of whole-brain activity ignore the roles of astrocytes while primarily focusing on neurons. Addressing this oversight, we introduce a biophysical neural mass network model, designed to capture the dynamic interplay between astrocytes and neurons via glutamatergic and GABAergic transmission pathways.

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