Losing Hope? The Environmental Crisis Today

Abstract Environmentalists and scientists who study the environment often give a pretty bleak picture of the future. Surveys of secular views on the environment suggest that the general public in the developed West are concerned about the state of the environment. After considering all of the environmental problems that are causing scientists to worry, this paper then concentrates on four: climate change; biodiversity loss; global water supply; and the increase in our human population. Finally we will see what scientists have to say about hope in a time of environmental crisis

Some thoughts on silicon and carbon trade-offs in plants

In 1983, Raven suggested that silica could substitute for lignin or cellulose as a structural material in plants, and should be favoured because of its lower energetic costs. He then asked the question why more plants did not use silica for structural support. Raven's idea eventually led to a whole series of investigations into the substitution of silicon for carbon in plants, so-called trade-offs. In this Opinion we offer some, hopefully helpful, thoughts on this research, and we attempt to answer Raven's question. We conclude that more focus on the distribution of silicon and carbon at the cellular level is needed, and that we should be more careful to avoid teleological thinking

RNA binding proteins in hematopoiesis and hematological malignancy.

RNA binding proteins (RBPs) regulate fundamental processes such as differentiation and self-renewal by enabling the dynamic control of protein abundance or isoforms, or through the regulation of non-coding RNA. RBPs are increasingly appreciated as being essential for normal hematopoiesis and they are understood to play fundamental roles in hematological malignancies by acting as oncogenes or tumor suppressors. Alternative splicing has been shown to play roles in the development of specific hematopoietic lineages and sequence specific mutations in RBPs lead to dysregulated splicing in myeloid and lymphoid leukemias. RBPs that regulate translation contribute to the development and function of hematological lineages, act as nodes for the action of multiple signaling pathways and contribute to hematological malignancies. These insights broaden our mechanistic understanding of the molecular regulation of hematopoiesis and offer opportunities to develop disease biomarkers and new therapeutic modalities.We thank the Medical Research Council, The Biotechnology and Biological Sciences Research Council BBS/E/B/000C0428, Bloodwise, Cancer Research Therapeutics and Wellcome for funding research in the author’s laboratories

Enzyme self-label-bound ATTO700 in single-molecule and super-resolution microscopy

Herein, we evaluate near-infrared ATTO700 as an acceptor in SNAP- and Halo-tag protein labelling for Förster Resonance Energy Transfer (FRET) by ensemble and single molecule measurements. Microscopy of cell surface proteins in live cells is perfomed including super-resolution stimulated emission by depletion (STED) nanoscopy

Physiological and pathophysiological concentrations of fatty acids induce lipid droplet accumulation and impair functional performance of tissue engineered skeletal muscle

Fatty acids (FA) exert physiological and pathophysiological effects leading to changes in skeletal muscle metabolism and function, however, in vitro models to investigate these changes are limited. These experiments sought to establish the effects of physiological and pathophysiological concentrations of exogenous FA upon the function of tissue engineered skeletal muscle (TESkM). Cultured initially for 14 days, C2C12 TESkM was exposed to FA‐free bovine serum albumin alone or conjugated to a FA mixture (oleic, palmitic, linoleic, and α‐linoleic acids [OPLA] [ratio 45:30:24:1%]) at different concentrations (200 or 800 µM) for an additional 4 days. Subsequently, TESkM morphology, functional capacity, gene expression and insulin signaling were analyzed. There was a dose response increase in the number and size of lipid droplets within the TESkM (p < .05). Exposure to exogenous FA increased the messenger RNA expression of genes involved in lipid storage (perilipin 2 [p < .05]) and metabolism (pyruvate dehydrogenase lipoamide kinase isozyme 4 [p < .01]) in a dose dependent manner. TESkM force production was reduced (tetanic and single twitch) (p < .05) and increases in transcription of type I slow twitch fiber isoform, myosin heavy chain 7, were observed when cultured with 200 µM OPLA compared to control (p < .01). Four days of OPLA exposure results in lipid accumulation in TESkM which in turn results in changes in muscle function and metabolism; thus, providing insight ito the functional and mechanistic changes of TESkM in response to exogenous FA.</div

Multiple-scale neuroendocrine signals connect brain and pituitary hormone rhythms

International audienceSignificance The hypothalamo–pituitary axis controls a wide range of homeostatic processes, including growth, stress, and reproduction. Despite this fact, the hypothalamic neuron firing patterns that lead to slowly evolving pituitary hormone rhythms remain enigmatic. Here, we used in vivo amperometric recordings in freely behaving mice to investigate how tuberoinfundibular neurons release dopamine (DA) at the median eminence (ME) to control pituitary prolactin secretion. Using this approach, we show that DA release occurs as multiple locally generated and time-scaled secretory events, which are integrated over a range of minutes across the ME. These results provide a broad physiological mechanism for the dialogue that occurs between the brain and pituitary to dictate hormone rhythms over multiple timescales, from ultradian to seasonal

Inpatient falls in older adults:a cohort study of antihypertensive prescribing pre- and post-fall

Abstract Background Falls are common during hospital admissions and may occur more frequently in patients who are taking antihypertensive medications, particularly in the context of normal to low blood pressure. The review and adjustment of these medications is an essential aspect of the post-fall assessment and should take place as soon as possible after the fall. Our aim was to investigate whether appropriate post-fall adjustments of antihypertensive medications are routinely made in a large National Health Service (NHS) Trust. Methods Inpatient records over an eight-month period were captured from an electronic prescribing system to identify older adults (≥80 years old) with normal/low blood pressures (< 140 mmHg systolic) who had a documented inpatient fall as these patients were considered to be at high risk of further falls. Prescribed antihypertensive medication on admission was then compared with the post-fall (within 24 h after the fall) and discharge prescriptions. Results A total of 146 patients were included in the analysis. Of those, 120 patients (82%) were taking the same number of antihypertensive medications in the 24 h after the fall as they were before; only 19 patients (13%) had a reduction in the number of medications and seven patients (5%) had an increase in medications during that period. Only 9% of the antihypertensive classes assessed were either stopped or reduced in dose immediately post-fall. In addition, 11 new antihypertensives were prescribed at this time. At discharge, half of the patients (n = 73) remained on the same number of antihypertensive medication as on admission, 51 patients (35%) were on fewer antihypertensives and 22 (15%) were on more. Additionally, no changes were made to individual antihypertensives in 49% of prescriptions; 34% were stopped or reduced in dose but 38 new agents were started by the time of discharge. Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers (ACEi/ARB) were the class of medications most commonly stopped or reduced (51%). Conclusions Antihypertensive prescriptions are frequently unchanged after an inpatient fall. Routine medication review needs to be part of post-fall assessments in hospital to reduce the risk of further falls

A metagenomic snapshot of taxonomic and functional diversity in an Alpine glacier cryoconite ecosystem:Alpine cryoconite metagenome

Cryoconite is a microbe–mineral aggregate which darkens the ice surface of glaciers. Microbial process and marker gene PCR-dependent measurements reveal active and diverse cryoconite microbial communities on polar glaciers. Here, we provide the first report of a cryoconite metagenome and culture-independent study of alpine cryoconite microbial diversity. We assembled 1.2 Gbp of metagenomic DNA sequenced using an Illumina HiScanSQ from cryoconite holes across the ablation zone of Rotmoosferner in the Austrian Alps. The metagenome revealed a bacterially-dominated community, with Proteobacteria (62% of bacterial-assigned contigs) and Bacteroidetes (14%) considerably more abundant than Cyanobacteria (2.5%). Streptophyte DNA dominated the eukaryotic metagenome. Functional genes linked to N, Fe, S and P cycling illustrated an acquisitive trend and a nitrogen cycle based upon efficient ammonia recycling. A comparison of 32 metagenome datasets revealed a similarity in functional profiles between the cryoconite and metagenomes characterized from other cold microbe–mineral aggregates. Overall, the metagenomic snapshot reveals the cryoconite ecosystem of this alpine glacier as dependent on scavenging carbon and nutrients from allochthonous sources, in particular mosses transported by wind from ice-marginal habitats, consistent with net heterotrophy indicated by productivity measurements. A transition from singular snapshots of cryoconite metagenomes to comparative analyses is advocated

The nature of the silicaphilic fluorescence of PDMPO

PDMPO (2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)methoxy)phenyl)oxazole), has unique silica specific fluorescence and is used in biology to understand biosilicification. This ‘silicaphilic’ fluorescence is not well understood nor is the response to local environmental variables like solvent and pH. We investigated PDMPO in a range of environments: using UV-vis and fluorescence spectroscopy supported by computational data, (SPARC, molecular dynamics simulations, density functional theory calculations), dynamic light scattering and zeta potential measurements to understand the PDMPO–silica interaction. From absorption data, PDMPO exhibited a pKa of 4.20 for PDMPOH22+ to PDMPOH+ . Fluorescence emission measurements revealed large shifts in excited state pKa* values with different behaviour when bound to silica (pKa* of 10.4). PDMPO bound to silica particles is located in the Stern layer with the dye exhibiting pH dependent depolarising motion. In aqueous solution, PDMPO showed strong chromaticity with correlation between the maximum emission wavelength for PDMPOH+* and dielectric constant (4.8–80). Additional chromatic effects were attributed to changes in solvent accessible surface area. Chromatic effects were also observed for silica bound dye which allow its use as a direct probe of bulk pH over a range far in excess of what is possible for the dye alone (3–5.2). The unique combination of chromaticity and excited state dynamics allows PDMPO to monitor pH from 3 to 13 while also reporting on surface environment opening a new frontier in the quantitative understanding of (bio)silicification