Kelp carbon sink potential decreases with warming due to accelerating decomposition.

Cycling of organic carbon in the ocean has the potential to mitigate or exacerbate global climate change, but major questions remain about the environmental controls on organic carbon flux in the coastal zone. Here, we used a field experiment distributed across 28° of latitude, and the entire range of 2 dominant kelp species in the northern hemisphere, to measure decomposition rates of kelp detritus on the seafloor in relation to local environmental factors. Detritus decomposition in both species were strongly related to ocean temperature and initial carbon content, with higher rates of biomass loss at lower latitudes with warmer temperatures.

Neuroethical and Societal Challenges of 21st Century Epidemics.

Neurologic and neuropsychiatric manifestations of COVID-19 are affecting a growing number of people worldwide. We provide a brief overview of these manifestations, contrasting them with those of other 21st century viral epidemics, as well as mitigation strategies, and societal and moral considerations related to the pandemic. We highlight unique concerns relating to COVID-19 given the scale of infection, mental health challenges faced by health care providers and the general public, and the unprecedented social consequences, including benefits and possible harms associated with continuous connectedness using modern digital communication.

Marine heatwaves and the collapse of marginal North Atlantic kelp forests.

Extreme climatic events including marine heatwaves (MHWs) are becoming more frequent and severe in the Anthropocene. However, our understanding of how these events affect population dynamics of ecologically important species is limited, in part because extreme events are rare and difficult to predict. Here, we quantified the occurrence and severity of MHWs over 60 years in warm range edge kelp forests on both sides of the North Atlantic.

Ecological feedbacks stabilize a turf-dominated ecosystem at the southern extent of kelp forests in the Northwest Atlantic.

Temperate marine ecosystems globally are undergoing regime shifts from dominance by habitat-forming kelps to dominance by opportunistic algal turfs. While the environmental drivers of shifts to turf are generally well-documented, the feedback mechanisms that stabilize novel turf-dominated ecosystems remain poorly resolved. Here, we document a decline of kelp Saccharina latissima between 1980 and 2018 at sites at the southernmost extent of kelp forests in the Northwest Atlantic and their replacement by algal turf.

Synergistic negative effects of thermal stress and altered food resources on echinoid larvae.

Multiple changes to the marine environment under climate change can have additive or interactive (antagonistic or synergistic) effects on marine organisms. Prompted by observations of anomalously warm sea temperatures and low chlorophyll concentrations during the 2013-2016 warm "Blob" event in the Northeast Pacific Ocean, we examined the combined effects of thermal stress and a shift in food resources on the development of a larval echinoid (Strongylocentrotus droebachiensis) in the laboratory. A high concentration of phytoplankton yielded faster echinus rudiment development at warm versus historical temperature, indicating a mitigating effect of abundant food on thermal stress; however, low phytoplankton concentration or a shift in diet to suspended kelp detritus, yielded slow development and high mortality at warm temperature.

Fertilization limitation of Diadema antillarum on coral reefs in the Florida Keys.

Mass mortality of the sea urchin Diadema antillarum due to disease outbreaks in 1983 and 1991 decimated populations in the Florida Keys, and they have yet to recover. Here, we use a coupled advection-diffusion and fertilization-kinetics model to test the hypothesis that these populations are fertilization limited. We found that fertilization success was ≥ 96% prior to the first disease outbreak, decreased substantially following recurrent disease to 3%, and has since remained low.

Validating the identity of Paramoeba invadens, the causative agent of recurrent mass mortality of sea urchins in Nova Scotia, Canada.

Green sea urchins Strongylocentrotus droebachiensis along the coast of Nova Scotia, Canada, suffer mass mortalities from infection by the pathogenic amoeba Paramoeba invadens Jones, 1985. It has been speculated that P. invadens could be a form of Neoparamoeba pemaquidensis, a species associated with disease in S.

New method for discovery of starch phenotypes in growing microalgal colonies.

To identify algal strains with altered starch metabolism from a large pool of candidates of growing algal colonies, we have developed a novel, high-throughput screening tool by combining gaseous bleaching of replica transferred colonies and subsequent iodine staining to visualize starch. Screening of healthy growing colonies of microalgae has not been possible previously because high levels of chlorophyll make the detection of starch with an iodine stain impossible. We demonstrated that chlorine dioxide (ClO(2)) removes essentially all chlorophyll from the colonies and enables high-throughput screening of, for example, a population of mutagenized cells or a culture collection isolated in a bioprospecting project.

Long dwell-time passage of DNA through nanometer-scale pores: kinetics and sequence dependence of motion.

A detailed understanding of the kinetics of DNA motion though nanometer-scale pores is important for the successful development of many of the proposed next-generation rapid DNA sequencing and analysis methods. Many of these approaches require DNA motion through nanopores to be slowed by several orders of magnitude from its native translocation velocity so that the translocation times for individual nucleotides fall within practical timescales for detection. With the increased dwell time of DNA in the pore, DNA-pore interactions begin to play an increasingly important role in translocation kinetics.

Psychiatrists' Use of Melatonin with Children.

Background:   Melatonin is gaining popularity as a sedative agent with children. This study sought to characterise this practice more precisely as well as examine aspects of its safety and efficacy in order to develop treatment guidelines.

Method:   Postal surveys of two groups of psychiatrists: generic child psychiatrists and psychiatrists who regularly treat learning disabled children.

Nicotinic acetylcholine receptor alpha4 subunit gene polymorphism and attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is a highly heritable, common psychiatric disorder that presents in childhood and that probably involves several genes. There are several lines of evidence suggesting that the nicotinic system may be functionally significant in ADHD: (a) nicotine promotes the release of dopamine and has been shown to improve attention in adults with ADHD, smokers and non-smokers; (b) ADHD is a significant risk factor for early initiation of cigarette smoking in children; (c) maternal cigarette smoking appears to be a risk factor for ADHD; (d) animal studies in rats and monkeys also suggest that nicotine may be involved in attentional systems and locomotor activity; and (e) a central nicotinic agonist, ABT-418, improves attention in both monkeys and ADHD adults. The current study examined the alpha 4 receptor, one of the sites of action of ABT-418.

Autistic symptoms in children with attention deficit-hyperactivity disorder.

Children with the syndrome of disorders of attention, motor control and perception (DAMP) invariably fill diagnostic criteria for attention deficit hyperactivity disorder (ADHD) and commonly have symptoms of autistic spectrum disorders. This study estimates the rate of autistic symptoms in a sample of children with ADHD by using the parent-rated Autism Criteria Checklist. A high proportion of parents (between 65-80%) reported significant difficulties in social interaction (particularly in empathy and peer relationships), and communication (particularly in imaginative ability, nonverbal communication and maintaining conversation).

Two-year outcome of children treated for depression.

Fifty-four children and adolescents (age 8-17) were assessed two years after a clinical intervention trial of cognitive-behavioural vs. non-focused treatment for depression. Eleven (20.

Detection of major and minor depression in children and adolescents: evaluation of the Mood and Feelings Questionnaire.

The detection of major and minor depression in children and adolescents was evaluated in an outpatient sample of 113 children employing the Mood and Feelings Questionnaire (both child and parent versions) and the K-SADS interview. Differences between depressed and nondepressed groups, those with major or minor depression, and depressed children compared with those comorbid for anxiety, were examined. Our findings support the validity of the MFQ as a screening instrument for major and minor depression in a population with a high proportion of depressed cases.

A randomised controlled out-patient trial of cognitive-behavioural treatment for children and adolescents with depression: 9-month follow-up.

Nine-month outcome data of a randomized controlled out-patient trial of cognitive-behavioural treatment (CBT) for children and adolescents with depression are presented. CBT was compared with a non-focussed intervention (NFI) in 56 subjects. At 9 months after thr termination of the trial, 21 children (37.

Neutrophil rolling altered by inhibition of L-selectin shedding in vitro.

The L-selectin adhesion molecule is involved in guiding leukocytes to sites of inflammation. L-selectin is cleaved by an unusual proteolytic activity at a membrane-proximal site resulting in rapid shedding from the cell surface. Although it has been demonstrated that L-selectin mediates, in part, the early event of leukocyte rolling under hydrodynamic flow, the contribution of shedding to L-selectin function has remained unknown.

Shedding of the lymphocyte L-selectin adhesion molecule is inhibited by a hydroxamic acid-based protease inhibitor. Identification with an L-selectin-alkaline phosphatase reporter.

Expression of the L-selectin adhesion molecule can be rapidly down-modulated by regulated proteolysis at a membrane-proximal site. The L-selectin secretase has remained undefined, and the secretase activity is resistant to a broad panel of common protease inhibitors. We have developed an L-selectin-alkaline phosphatase reporter, consisting of the ectodomain of human placental alkaline phosphatase fused to the membrane-proximal cleavage, transmembrane, and cytoplasmic domains of L-selectin, to aid in the screening for L-selectin secretase inhibitors.

Child sexual abuse: helping children and their families.

The reality of child sexual abuse has only recently been accepted by professionals. Previously, treatment strategies were aimed at adult survivors rather than at children. Treatment programmes for children have a short history and their long-term effects cannot be validated yet, although some attempts have been made (Bentovim et al, 1987).