Spontaneous Ca2+ transients of neural cells is a hallmark of the developing nervous system. It is widely accepted that chemical signals, like neurotransmitters, contribute to spontaneous Ca2+ ...transients in the nervous system. Here, we reveal an additional mechanism of spontaneous Ca2+ transients that is mechanosensitive in the peripheral nervous system (PNS) using intravital imaging of growing dorsal root ganglia (DRG) in zebrafish embryos. GCaMP6s imaging shows that developing DRG satellite glia contain distinct spontaneous Ca2+ transients, classified into simultaneous, isolated, and microdomains. Longitudinal analysis over days in development demonstrates that as DRG satellite glia become more synchronized, isolated Ca2+ transients remain constant. Using a chemical screen, we identify that Ca2+ transients in DRG glia are dependent on mechanical properties, which we confirmed using an experimental application of mechanical force. We find that isolated spontaneous Ca2+ transients of the glia during development is altered by manipulation of mechanosensitive protein Piezo1, which is expressed in the developing ganglia. In contrast, simultaneous Ca2+ transients of DRG satellite glia is not Piezo1-mediated, thus demonstrating that distinct mechanisms mediate subtypes of spontaneous Ca2+ transients. Activating Piezo1 eventually impacts the cell abundance of DRG cells and behaviors that are driven by DRG neurons. Together, our results reveal mechanistically distinct subtypes of Ca2+ transients in satellite glia and introduce mechanobiology as a critical component of spontaneous Ca2+ transients in the developing PNS.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recent imaging studies show that the formation of neural connections in the central nervous system is a highly dynamic process. The iterative formation and elimination of synapses and neuronal ...branches result in the formation of a much larger number of trial connections than is maintained in the mature brain. Neural activity modulates development through biasing this process of formation and elimination, promoting the formation and stabilization of appropriate synaptic connections on the basis of functional activity patterns.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Anthropogenic activity is changing Earth's climate and ecosystems in ways that are potentially dangerous and disruptive to humans. Greenhouse gas concentrations in the atmosphere continue to rise, ...ensuring that these changes will be felt for centuries beyond 2100, the current benchmark for projection. Estimating the effects of past, current, and potential future emissions to only 2100 is therefore short‐sighted. Critical problems for food production and climate‐forced human migration are projected to arise well before 2100, raising questions regarding the habitability of some regions of the Earth after the turn of the century. To highlight the need for more distant horizon scanning, we model climate change to 2500 under a suite of emission scenarios and quantify associated projections of crop viability and heat stress. Together, our projections show global climate impacts increase significantly after 2100 without rapid mitigation. As a result, we argue that projections of climate and its effects on human well‐being and associated governance and policy must be framed beyond 2100.
We argue that projections of climate and its effects on human well‐being and associated governance and policy must be framed beyond 2100. To highlight the need for more distant horizon scanning, we model climate change to 2500 under a suite of emission scenarios and quantify associated projections of crop viability and heat stress. Together, our projections show global climate impacts increase significantly after 2100 without rapid mitigation.
The apple maggot, Rhagoletis pomonella (Walsh), was introduced into the apple-growing regions of the Pacific Northwest in the U.S.A. during the past 60–100 yr. Apple maggot (larvae, puparia, and ...adults) is difficult to distinguish from its morphologically similar sister species, Rhagoletis zephyria Snow, which is native and abundant in the Pacific Northwest. While morphological identifications are common practice, a simple, inexpensive assay based on genetic differences would be very useful when morphological traits are unclear. Here we report nucleotide substitution and insertion–deletion mutations in the nontranscribed spacer (NTS) of the ribosomal RNA gene cistron of R. pomonella and R. zephyria that appear to be diagnostic for these two fly species. Insertion–deletion variation is substantial and results in a 49 base-pair difference in PCR amplicon size between R. zephyria and R. pomonella that can be scored using agarose gel electrophoresis. PCR amplification and DNA sequencing of 766 bp of the NTS region from 38 R. pomonella individuals and 35 R. zephyria individuals from across their geographic ranges led to the expected PCR fragments of approx. 840 bp and 790 bp, respectively, as did amplification and sequencing of a smaller set of 26 R. pomonella and 16 R. zephyria flies from a sympatric site in Washington State. Conversely, 633 bp mitochondrial COI barcode sequences from this set of flies were polyphyletic with respect to R. pomonella and R. zephyria. Thus, differences in NTS PCR products on agarose gels potentially provide a simple way to distinguish between R. pomonella and R. zephyria.
Surface Wrinkles for Smart Adhesion Chan, E. P.; Smith, E. J.; Hayward, R. C. ...
Advanced materials (Weinheim),
02/2008, Letnik:
20, Številka:
4
Journal Article
Recenzirano
A novel and highly scalable approach to generating a reusable, “smart” polymer adhesive based on surface wrinkling is presented. The wrinkling approach to patterning the polymer film is based on a ...combination of swelling and lateral confinement. The control of adhesion, or “smart” adhesion utilizes the mechanism of contact line splitting. This enhancement is controlled by the wrinkle wavelength, which is tuned by the degree of lateral confinement.
Obesity is a global pandemic associated with macro- and microvascular endothelial dysfunction. Microvascular endothelial dysfunction has recently emerged as a significant risk factor for the ...development of cognitive impairment. In this review, we present evidence from clinical and preclinical studies supporting a role for obesity in cognitive impairment. Next, we discuss how obesity-related hyperinsulinemia/insulin resistance, systemic inflammation, and gut dysbiosis lead to cognitive impairment through induction of endothelial dysfunction and disruption of the blood brain barrier. Finally, we outline the potential clinical utility of dietary interventions, exercise, and bariatric surgery in circumventing the impacts of obesity on cognitive function.
This book explores a largely forgotten legacy of multicultural political thought and practice from within Eastern Europe and examines its relevance to post-Cold War debates on state and nationhood. ...Featuring a Preface by former UK Home Secretary Charles Clarke, it weaves theory and practice to challenge established understandings of the nation state.
Eastern Europe is still too often viewed through the prism of ethnic conflict, which overlooks the region's positive contribution to modern debates on the political management of ethno-cultural diversity, and towards the construction of a united Europe 'beyond the nation-state'. Based on extensive archival research in Estonia, Latvia, Germany, Russia, as well as the League of Nations Archive in Geneva, this book explores this neglected multicultural legacy and assesses its significance in the post-Cold War era, which has seen the reappearance of national cultural autonomy laws in several states of Eastern Europe.
Ethnic Diversity and the Nation State is invaluable reading for students and scholars of political science, history, sociology and European studies, and also for policy makers and others interested in minority rights and ethnic conflict regulation.
Abstract
Scientifically rigorous guidance to policy makers on mitigation options for meeting the Paris Agreement long-term temperature goal requires an evaluation of long-term global-warming ...implications of greenhouse gas emissions pathways. Here we employ a uniform and transparent methodology to evaluate Paris Agreement compatibility of influential institutional emission scenarios from the grey literature, including those from Shell, BP, and the International Energy Agency. We compare a selection of these scenarios analysed with this methodology to the Integrated Assessment Model scenarios assessed by the Intergovernmental Panel on Climate Change. We harmonize emissions to a consistent base-year and account for all greenhouse gases and aerosol precursor emissions, ensuring a self-consistent comparison of climate variables. An evaluation of peak and end-of-century temperatures is made, with both being relevant to the Paris Agreement goal. Of the scenarios assessed, we find that only the IEA Net Zero 2050 scenario is aligned with the criteria for Paris Agreement consistency employed here. We investigate root causes for misalignment with these criteria based on the underlying energy system transformation.
Orexins (hypocretins) are two peptides (orexin A and B) produced from the pre-pro-orexin precursor and expressed in a limited region of dorsolateral hypothalamus. Orexins were originally thought to ...specifically mediate feeding and promote wakefulness, but it is now clear that they participate in a wide range of behavioral and physiological processes under select circumstances. Orexins primarily mediate behavior under situations of high motivational relevance, such as during physiological need states, exposure to threats or reward opportunities. We hypothesize that many behavioral functions of orexins (including regulation of sleep/wake cycling) reflect a fundamentally integrated function for orexins in translating motivational activation into organized suites of psychological and physiological processes supporting adaptive behaviors. We also discuss how numerous forms of neural heterogeneity modulate this function, allowing orexin neurons to organize diverse, adaptive responses in a variety of motivationally relevant situations. Thus, the involvement of orexins in diverse behaviors may reflect a common underlying function for this peptide system.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Restoration of degraded coral reef communities is dependent on successful recruitment and survival of new coral planulae. Degraded reefs are often characterized by high cover of fleshy algae and high ...microbial densities, complemented by low abundance of coral and coral recruits. Here, we investigated how the presence and abundance of macroalgae and microbes affected recruitment success of a common Hawaiian coral. We found that the presence of algae reduced survivorship and settlement success of planulae. With the addition of the broad-spectrum antibiotic, ampicillin, these negative effects were reversed, suggesting that algae indirectly cause planular mortality by enhancing microbial concentrations or by weakening the coral's resistance to microbial infections. Algae further reduced recruitment success of corals as planulae preferentially settled on algal surfaces, but later suffered 100% mortality. In contrast to survival, settlement was unsuccessful in treatments containing antibiotics, suggesting that benthic microbes may be necessary to induce settlement. These experiments highlight potential complex interactions that govern the relationships between microbes, algae and corals and emphasize the importance of microbial dynamics in coral reef ecology and restoration.
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