Early apoptosis detection in canine granulosa cells through the analysis of BCL-2 and BAX proteins during the follicular development associated with oocyte maturation.

The objective of this study was to investigate the early follicular apoptosis in canine ovarian follicles by examining the expression of anti-apoptotic BCL-2 and pro-apoptotic BAX proteins throughout the estrous cycle associated with oocyte maturation. Follicular cells from preantral and antral follicles of varying sizes were isolated and grouped based on follicle type and estrous phase. Antral follicles underwent flow cytometry analysis, whereas preantral follicles were subjected to Western blotting.

Ecological succession and the competition-colonization trade-off in microbial communities.

Background: During range expansion in spatially distributed habitats, organisms differ from one another in terms of their patterns of localization versus propagation. To exploit locations or explore the landscape? This is the competition-colonization trade-off, a dichotomy at the core of ecological succession. In bacterial communities, this trade-off is a fundamental mechanism towards understanding spatio-temporal fluxes in microbiome composition.

Variance in Landscape Connectivity Shifts Microbial Population Scaling.

Understanding mechanisms shaping distributions and interactions of soil microbes is essential for determining their impact on large scale ecosystem services, such as carbon sequestration, climate regulation, waste decomposition, and nutrient cycling. As the functional unit of soil ecosystems, we focus our attention on the spatial structure of soil macroaggregates. Emulating this complex physico-chemical environment as a patchy habitat landscape we investigate the effect of changing the connectivity features of this landscape as forms a metapopulation.

Economic policy uncertainty and presidential approval: Evidence from Latin America.

This paper analyzes the extent to which economic policy uncertainty affects presidential approval in four Latin American countries (Brazil, Chile, Colombia, and Mexico). Using panel (time-series cross-sectional) estimation methods, we show that economic policy uncertainty has a negative impact on presidential approval in our sample. A one-standard-deviation increase in the level of economic uncertainty reduces presidential approval by approximately 12 percent.

Expansion, Exploitation and Extinction: Niche Construction in Ephemeral Landscapes.

We aim to understand general consequences of niche construction on metapopulation dynamics in ephemeral landscapes. To this effect, a contact process-like stochastic spatial model is introduced where local populations colonize and go extinct on a dynamic landscape of habitable and destroyed patches. In contrast to previous models, where the extinction threshold is a consequence of available niche rendered by global rates of patch destruction/renewal, here we investigate how the metapopulation persists when they are the sole generators of their own niche.

Association Between Fractional Amplitude of Low-Frequency Spontaneous Fluctuation and Degree Centrality in Children and Adolescents.

The fractional amplitude of low-frequency fluctuations (fALFFs) of the BOLD signal have been successfully applied as exploratory tools in neuroimaging. This metric has been useful in mapping brain functional changes in many clinical populations. However, little is known about the neurophysiological correlates of fALFF.

What Does Not Kill You Makes You Stronger.

Colicin production is an extreme form of labor division; cells lyse after making the toxin! Stochastic phenotype switching allows producers to outcompete sensitive strains since colicin release frees up vacancy. If patch dynamics does not kill you, it stimulates adaptation to a dynamic habitat landscape which selects for rapid dispersal.

PPARs in the central nervous system: roles in neurodegeneration and neuroinflammation.

Over 25 years have passed since peroxisome proliferators-activated receptors (PPARs), were first described. Like other members of the nuclear receptors superfamily, PPARs have been defined as critical sensors and master regulators of cellular metabolism. Recognized as ligand-activated transcription factors, they are involved in lipid, glucose and amino acid metabolism, taking part in different cellular processes, including cellular differentiation and apoptosis, inflammatory modulation and attenuation of acute and chronic neurological damage in vivo and in vitro.

Connectome hubs at resting state in children and adolescents: Reproducibility and psychopathological correlation.

Functional brain hubs are key integrative regions in brain networks. Recently, brain hubs identified through resting-state fMRI have emerged as interesting targets to increase understanding of the relationships between large-scale functional networks and psychopathology. However, few studies have directly addressed the replicability and consistency of the hub regions identified and their association with symptoms.

Coordinated brain development: exploring the synchrony between changes in grey and white matter during childhood maturation.

Brain development during childhood and early adolescence is characterized by global changes in brain architecture. Neuroimaging studies have revealed overall decreases in cortical thickness (CT) and increases in fractional anisotropy (FA). Furthermore, previous studies have shown that certain cortical regions display coordinated growth during development.

HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis.

The onset of psychosis is thought to involve interactions between environmental stressors and the brain, with cortisol as a putative mediator. We examined the relationship between the cortisol stress response and brain structure in subjects at ultra-high risk (UHR) for psychosis. Waking salivary cortisol was measured in 22 individuals at UHR for psychosis and 17 healthy controls.

Rhein-Huprine Derivatives Reduce Cognitive Impairment, Synaptic Failure and Amyloid Pathology in AβPPswe/PS-1 Mice of Different Ages.

Alzheimer's disease (AD) is a neurodegenerative disorder in which the amyloid-β (Aβ) peptide plays a key role in synaptic impairment and memory decline associated with neuronal dysfunction and intra-neuronal accumulation of hyperphosphorylated tau protein. Two novel enantiopure rhein-huprine hybrids ((+)-1 and (-)-1) exhibit potent inhibitory effects against human acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), BACE-1 and both Aβ and tau antiaggregation activity in vitro and reduction on the amyloid precursor protein (APP) processing in vivo. Interestingly, in this work, we observed beneficial effects with both (+)- and (-)-1 in the reversion of the neuropathology presented in the AβPPswe/PS-1 Alzheimer´s model, including a reduction in the Aβ levels, tau phosphorylation and memory impairment with both treatments.

Density-dependent adaptive resistance allows swimming bacteria to colonize an antibiotic gradient.

During antibiotic treatment, antibiotic concentration gradients develop. Little is know regarding the effects of antibiotic gradients on populations of nonresistant bacteria. Using a microfluidic device, we show that high-density motile Escherichia coli populations composed of nonresistant bacteria can, unexpectedly, colonize environments where a lethal concentration of the antibiotic kanamycin is present.

Default mode network maturation and psychopathology in children and adolescents.

Background: The human default mode (DMN) is involved in a wide array of mental disorders. Current knowledge suggests that mental health disorders may reflect deviant trajectories of brain maturation.

Method: We studied 654 children using functional magnetic resonance imaging (fMRI) scans under a resting-state protocol.

The idiosyncrasy of spatial structure in bacterial competition.

Background: The spatial structure of a habitat can have a strong impact on community dynamics. Different experimental approaches exist to explore the effect of spatial structure on bacterial communities. To investigate the effect of 'space', a single implementation of spatial structure is often contrasted to bacterial community dynamics in well-mixed cultures.

Interactions of the antiviral and antiparkinson agent amantadine with lipid membranes and human erythrocytes.

Aimed to better understand the molecular mechanisms of its interactions with cell membranes, human erythrocyte and molecular models of the red cell membrane were utilized. The latter consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. The capacity of amantadine to perturb the bilayer structures of DMPC and DMPE was evaluated by X-ray diffraction, fluorescence spectroscopy and differential scanning calorimetry (DSC).

P2C-Type ATPases and Their Regulation.

P2C-type ATPases are a subfamily of P-type ATPases comprising Na(+)/K(+)-ATPase and H(+)/K(+)-ATPase. Na(+)/K(+)-ATPase is ubiquitously expressed and has been implicated in several neurological diseases, whereas H(+)/K(+)-ATPase is found principally in the colon, stomach, and kidney. Both ATPases have two subunits, α and β, but Na(+)/K(+)-ATPase also has a regulatory subunit called FXYD, which has an important role in cancer.

Accelerating Alzheimer's research through 'natural' animal models.

Purpose Of Review: Alzheimer's disease is a complex multifactorial age-related neurodegenerative disorder. Current transgenic animal models do not fully recapitulate human Alzheimer's disease at the molecular, cellular and behavioural levels. This review aims to address the clinical relevance of using 'physiologically' aged rats, dogs and Octodon degus, as more representative 'natural' ecologically valid models to elucidate mechanistic aspects of Alzheimer's disease, and for the development of therapeutic agents to attenuate age-related cognitive decline.

Andrographolide reduces cognitive impairment in young and mature AβPPswe/PS-1 mice.

Alzheimer's disease (AD) is a neurodegenerative disorder in which the amyloid-β (Aβ) oligomers are a key factor in synaptic impairment and in spatial memory decline associated with neuronal dysfunction. This impairment includes synaptic failure associated with the loss of synaptic proteins that contribute to AD progression. Interestingly, the use of natural compounds is an emergent conceptual strategy in the search for drugs with therapeutic potentials for treating neurodegenerative disorders.

Metal and complementary molecular bioimaging in Alzheimer's disease.

Alzheimer's disease (AD) is the leading cause of dementia in the elderly, affecting over 27 million people worldwide. AD represents a complex neurological disorder which is best understood as the consequence of a number of interconnected genetic and lifestyle variables, which culminate in multiple changes to brain structure and function. These can be observed on a gross anatomical level in brain atrophy, microscopically in extracellular amyloid plaque and neurofibrillary tangle formation, and at a functional level as alterations of metabolic activity.

Role of Wnt signaling in tissue fibrosis, lessons from skeletal muscle and kidney.

Several studies have provided clear evidence of the importance of Wnt signaling in the function of several tissues. Wnt signaling has been related to several cellular processes including pre-natal development, cell division, regeneration and stem cell generation. By contrast, deregulation of this pathway has been associated with several diseases such as cancer, Alzheimer's disease, diabetes and, in recent years, fibrotic diseases in tissues such as skeletal muscle and kidney.

Cdc42 coordinates proliferation, polarity, migration, and differentiation of small intestinal epithelial cells in mice.

Background & Aims: Cdc42 is a Rho GTPase that regulates diverse cellular functions, including proliferation, differentiation, migration, and polarity. In the intestinal epithelium, a balance among these events maintains homeostasis. We used genetic techniques to investigate the role of Cdc42 in intestinal homeostasis and its mechanisms.

Exosomes: mediators of communication in eukaryotes.

In addition to the established mechanisms of intercellular signaling, a new way of communication has gained much attention in the last decade: communication mediated by exosomes. Exosomes are nanovesicles (with a diameter of 40-120 nm) secreted into the extracellular space by the multivesicular endosome after its outer membrane fuses with the plasma membrane. Once released, exosomes modulate the response of the recipient cells that recognize them.

Transfer of vesicles from schwann cells to axons: a novel mechanism of communication in the peripheral nervous system.

Schwann cells (SCs) are the glial component of the peripheral nervous system, with essential roles during development and maintenance of axons, as well as during regenerative processes after nerve injury. SCs increase conduction velocities by myelinating axons, regulate synaptic activity at presynaptic nerve terminals and are a source of trophic factors to neurons. Thus, development and maintenance of peripheral nerves are crucially dependent on local signaling between SCs and axons.