Ocean warming has greater and more consistent negative effects than ocean acidification on the growth and health of subtropical macroalgae

Macroalgae are the major habitat-forming organisms in many coastal temperate and subtropical marine systems. Although climate change has been identified as a major threat to the persistence of macroalgal beds, the combined effects of ocean warming and ocean acidification on algal performance are poorly understood. Here we investigate the effects of increased temperature and acidification on the growth, calcification and nutritional content of 6 common subtropical macroalgae; Sargassum linearifolium, Ulva sp., Amphiroa anceps, Corallina officinalis, Delisea pulchra and Laurencia decussata. Algae were reared in a factorial cross of 3 temperatures (23°C [ambient], 26°C and 28°C) and 3 pH levels (8.1 [ambient], 7.8 and 7.6) for 2 wk. The highest (28°C) temperature decreased the growth of all 6 macroalgal species, irrespective of the pH levels. In contrast, the effect of decreased pH on growth was variable. The growth of Ulva sp. and C. officinalis increased, L. decussata decreased, while the remaining 3 species were unaffected. Interestingly, the differential responses of macroalgae to ocean acidification were unrelated to whether or not a species was a calcifying alga, or their carbon-uptake mechanism—2 processes that are predicted to be sensitive to decreased pH. The growth of the calcifying algae (C. officinalis and A. anceps) was not affected by reduced pH but calcification of these 2 algae was reduced when exposed to a combination of reduced pH and elevated temperature. The 3 species capable of uptake of bicarbonate, S. linearifolium, L. decussata and Ulva sp., displayed positive, negative and neutral changes in growth, respectively, in response to reduced pH. The C:N ratio for 5 of the 6 species was unaffected by either pH or temperature. The consistent and predictable negative effects of temperature on the growth and calcification of subtropical macroalgae suggests that this stressor poses a greater threat to the persistence of subtropical macroalgal populations than ocean acidification under ongoing and future climate change

Three-body correlations in Borromean halo nuclei

Three-body correlations in the dissociation of two-neutron halo nuclei are explored using a technique based on intensity interferometry and Dalitz plots. This provides for the combined treatment of both the n-n and core-n interactions in the exit channel. As an example, the breakup of 14Be into 12Be+n+n by Pb and C targets has been analysed and the halo n-n separation extracted. A finite delay between the emission of the neutrons in the reaction on the C target was observed and is attributed to 13Be resonances populated in sequential breakup.Comment: 5 pages, 4 figures, submitted to PR

PNAS plus: plasmodium falciparum responds to amino acid starvation by entering into a hibernatory state

The human malaria parasite Plasmodium falciparum is auxotrophic for most amino acids. Its amino acid needs are met largely through the degradation of host erythrocyte hemoglobin; however the parasite must acquire isoleucine exogenously, because this amino acid is not present in adult human hemoglobin. We report that when isoleucine is withdrawn from the culture medium of intraerythrocytic P. falciparum, the parasite slows its metabolism and progresses through its developmental cycle at a reduced rate. Isoleucine-starved parasites remain viable for 72 h and resume rapid growth upon resupplementation. Protein degradation during starvation is important for maintenance of this hibernatory state. Microarray analysis of starved parasites revealed a 60% decrease in the rate of progression through the normal transcriptional program but no other apparent stress response. Plasmodium parasites do not possess a TOR nutrient-sensing pathway and have only a rudimentary amino acid starvation-sensing eukaryotic initiation factor 2α (eIF2α) stress response. Isoleucine deprivation results in GCN2-mediated phosphorylation of eIF2α, but kinase-knockout clones still are able to hibernate and recover, indicating that this pathway does not directly promote survival during isoleucine starvation. We conclude that P. falciparum, in the absence of canonical eukaryotic nutrient stress-response pathways, can cope with an inconsistent bloodstream amino acid supply by hibernating and waiting for more nutrient to be provided

Structure of 13^{13}Be probed via secondary beam reactions

The low-lying level structure of the unbound neutron-rich nucleus $^{13}$Be has been investigated via breakup on a carbon target of secondary beams of $^{14,15}$B at 35 MeV/nucleon. The coincident detection of the beam velocity $^{12}$Be fragments and neutrons permitted the invariant mass of the $^{12}$Be+$n$ and $^{12}$Be+$n$+$n$ systems to be reconstructed. In the case of the breakup of $^{15}$B, a very narrow structure at threshold was observed in the $^{12}$Be+$n$ channel. Contrary to earlier stable beam fragmentation studies which identified this as a strongly interacting $s$-wave virtual state in $^{13}$Be, analysis here of the $^{12}$Be+$n$+$n$ events demonstrated that this was an artifact resulting from the sequential-decay of the $^{14}$Be(2$^+$) state. Single-proton removal from $^{14}$B was found to populate a broad low-lying structure some 0.70 MeV above the neutron-decay threshold in addition to a less prominent feature at around 2.4 MeV. Based on the selectivity of the reaction and a comparison with (0-3)$\hbar\omega$ shell-model calculations, the low-lying structure is concluded to most probably arise from closely spaced J$^\pi$=1/2$^+$ and 5/2$^+$ resonances (E$_r$=0.40$\pm$0.03 and 0.85$^{+0.15}_{-0.11}$ MeV), whilst the broad higher-lying feature is a second 5/2$^+$ level (E$_r$=2.35$\pm$0.14 MeV). Taken in conjunction with earlier studies, it would appear that the lowest 1/2$^+$ and 1/2$^-$ levels lie relatively close together below 1 MeV.Comment: 14 pages, 13 figures, 2 tables. Accepted for publication in Physical Review

The detection of neutron clusters

A new approach to the production and detection of bound neutron clusters is presented. The technique is based on the breakup of beams of very neutron-rich nuclei and the subsequent detection of the recoiling proton in a liquid scintillator. The method has been tested in the breakup of 11Li, 14Be and 15B beams by a C target. Some 6 events were observed that exhibit the characteristics of a multineutron cluster liberated in the breakup of 14Be, most probably in the channel 10Be+4n. The various backgrounds that may mimic such a signal are discussed in detail.Comment: 11 pages, 12 figures, LPCC 01-1

Rapid Cellular Turnover in Adipose Tissue

It was recently shown that cellular turnover occurs within the human adipocyte population. Through three independent experimental approaches — dilution of an inducible histone 2B-green fluorescent protein (H2BGFP), labeling with the cell cycle marker Ki67 and incorporation of BrdU — we characterized the degree of cellular turnover in murine adipose tissue. We observed rapid turnover of the adipocyte population, finding that 4.8% of preadipocytes are replicating at any time and that between 1–5% of adipocytes are replaced each day. In light of these findings, we suggest that adipose tissue turnover represents a possible new avenue of therapeutic intervention against obesity

Co-expression network of neural-differentiation genes shows specific pattern in schizophrenia

Background: Schizophrenia is a neurodevelopmental disorder with genetic and environmental factors contributing to its pathogenesis, although the mechanism is unknown due to the difficulties in accessing diseased tissue during human neurodevelopment. The aim of this study was to find neuronal differentiation genes disrupted in schizophrenia and to evaluate those genes in post-mortem brain tissues from schizophrenia cases and controls. Methods: We analyzed differentially expressed genes (DEG), copy number variation (CNV) and differential methylation in human induced pluripotent stem cells (hiPSC) derived from fibroblasts from one control and one schizophrenia patient and further differentiated into neuron (NPC). Expression of the DEG were analyzed with microarrays of post-mortem brain tissue (frontal cortex) cohort of 29 schizophrenia cases and 30 controls. A Weighted Gene Co-expression Network Analysis (WGCNA) using the DEG was used to detect clusters of co-expressed genes that werenon-conserved between adult cases and controls brain samples. Results: We identified methylation alterations potentially involved with neuronal differentiation in schizophrenia, which displayed an over-representation of genes related to chromatin remodeling complex (adjP = 0.04). We found 228 DEG associated with neuronal differentiation. These genes were involved with metabolic processes, signal transduction, nervous system development, regulation of neurogenesis and neuronal differentiation. Between adult brain samples from cases and controls there were 233 DEG, with only four genes overlapping with the 228 DEG, probably because we compared single cell to tissue bulks and more importantly, the cells were at different stages of development. The comparison of the co-expressed network of the 228 genes in adult brain samples between cases and controls revealed a less conserved module enriched for genes associated with oxidative stress and negative regulation of cell differentiation. Conclusion: This study supports the relevance of using cellular approaches to dissect molecular aspects of neurogenesis with impact in the schizophrenic brain. We showed that, although generated by different approaches, both sets of DEG associated to schizophrenia were involved with neocortical development. The results add to the hypothesis that critical metabolic changes may be occurring during early neurodevelopment influencing faulty development of the brain and potentially contributing to further vulnerability to the illness.We thank the patients, doctors and nurses involved with sample collection and the Stanley Medical Research Institute. This research was supported by either Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq #17/2008) and Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ). MM (CNPq 304429/2014-7), ACT (FAPESP 2014/00041-1), LL (CAPES 10682/13-9) HV (CAPES) and BP (PPSUS 137270) were supported by their fellowshipsinfo:eu-repo/semantics/publishedVersio

INVESTIGATE-I (INVasive Evaluation before Surgical Treatment of Incontinence Gives Added Therapeutic Effect?): study protocol for a mixed methods study to assess the feasibility of a future randomised controlled trial of the clinical utility of invasive urodynamic testing

<p>Abstract</p> <p>Background</p> <p>Urinary incontinence is an important health problem to the individual sufferer and to health services. Stress and stress predominant mixed urinary incontinence are increasingly managed by surgery due to advances in surgical techniques. Despite the lack of evidence for its clinical utility, most clinicians undertake invasive urodynamic testing (IUT) to confirm a functional diagnosis of urodynamic stress incontinence before offering surgery for this condition. IUT is expensive, embarrassing and uncomfortable for women and carries a small risk. Recent systematic reviews have confirmed the lack of high quality evidence of effectiveness.</p> <p>The aim of this pilot study is to test the feasibility of a future definitive randomised control trial that would address whether IUT alters treatment decisions and treatment outcome in these women and would test its clinical and cost effectiveness.</p> <p>Methods/design</p> <p>This is a mixed methods pragmatic multicentre feasibility pilot study with four components:-</p> <p>(a) A multicentre, external pilot randomised trial comparing basic clinical assessment with non-invasive tests and IUT. The outcome measures are rates of recruitment, randomisation and data completion. Data will be used to estimate sample size necessary for the definitive trial.</p> <p>(b) Qualitative interviews of a purposively sampled sub-set of women eligible for the pilot trial will explore willingness to participate, be randomised and their overall trial experience.</p> <p>(c) A national survey of clinicians to determine their views of IUT in this context, the main outcome being their willingness to randomise patients into the definitive trial.</p> <p>(d) Qualitative interviews of a purposively sampled group of these clinicians will explore whether and how they use IUT to inform their decisions.</p> <p>Discussion</p> <p>The pilot trial will provide evidence of feasibility and acceptability and therefore inform the decision whether to proceed to the definitive trial. Results will inform the design and conduct of the definitive trial and ensure its effectiveness in achieving its research aim.</p> <p>Trial registration number</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN71327395">ISRCTN71327395</a> assigned 7^thJune 2010.</p