88 research outputs found
Evidence from Cd/Ca ratios in foraminifera for greater upwelling off California 4,000 years ago
Upwelling of nutrient-rich Pacific deep water along the North American west coast is ultimately driven by the temperature difference between air masses over land and over the ocean. The intensity of upwelling, and biological production in the region, could therefore be affected by anthropogenic climate change. Examination of the geological record is one way to study the link between climate and upwelling. Because Pacific deep water is enriched in cadmium, dissolved cadmium concentrations in coastal water off central California reflect the intensity of upwelling. By demonstrating that the Cd/Ca ratio in the shell of a benthic foraminifer, Elphidiella hannai, is proportional to the Cd concentration in coastal water, we show here that foraminiferal Cd/Ca ratios can be used to detect past changes in mean upwelling intensity. Examination of a sediment core from the mouth of San Francisco Bay reveals that foraminiferal Cd/Ca decreased by about 30% from 4,000 years ago to the present, probably because of a reduction in coastal upwelling. This observation is consistent with predictions of atmospheric general circulation models that northwesterly winds, which drive upwelling, became weaker over this period as summer insolation of the Northern Hemisphere decreased. © 1992 Nature Publishing Group
Evaluating real-time internet therapy and online self-help for problematic alcohol consumers: a three-arm RCT protocol
<p>Abstract</p> <p>Background</p> <p>Only a minority of all alcohol- and drug abusers is receiving professional care. In an attempt to narrow this treatment gap, treatment facilities experiment with online healthcare. Therefore, it is important to test the (cost-)effectiveness of online health interventions in a randomized clinical trial.</p> <p>Methods</p> <p>This paper presents the protocol of a three-arm randomized clinical trial to test the (cost-) effectiveness of online treatment for problem drinkers. Self-help online, therapy online and a waiting list are tested against each other. Primary outcome is change in alcohol consumption. Secondary outcome measures include quality of life and working ability. Incremental cost-effectiveness ratios for self-help online alcohol and therapy online alcohol will be calculated. The predictive validity of participant characteristics on treatment adherence and outcome will be explored.</p> <p>Discussion</p> <p>To our best knowledge, this randomized clinical trial will be the first to test the effectiveness of therapy online against both self-help online and a waiting-list. It will provide evidence on (cost-) effectiveness of online treatment for problem drinkers and investigate outcome predictors.</p> <p>Trial registration</p> <p>This trial is registered in the Dutch Trialregister (Cochrane Collaboration) and traceable as NTR-TC1155.</p
Revealing Dissociable Attention Biases in Chronic Smokers Through an Individual-Differences Approach
Addiction is accompanied by attentional biases (AB), wherein drug-related cues grab attention
independently of their perceptual salience. AB have emerged in different flavours depending on
the experimental approach, and their clinical relevance is still debated. In chronic smokers we
sought evidence for dissociable attention abnormalities that may play distinct roles in the clinical
manifestations of the disorder. Fifty smokers performed a modified visual probe-task measuring two
forms of AB and their temporal dynamics, and data on their personality traits and smoking history/
status were collected. Two fully dissociable AB effects were found: A Global effect, reflecting the overall
impact of smoke cues on attention, and a Location-specific effect, indexing the impact of smoke cues
on visuospatial orienting. Importantly, the two effects could be neatly separated from one another
as they: (i) unfolded with dissimilar temporal dynamics, (ii) were accounted for by different sets of
predictors associated with personality traits and smoking history and (iii) were not correlated with one
another. Importantly, the relevance of each of these two components in the single individual depends
on a complex blend of personality traits and smoking habits, a result that future efforts addressing the
clinical relevance of addiction-related AB should take into careful consideration.This study was supported by funding provided by the University of Verona to CDL, CC and L
Nuclear Calcium Signaling Controls Expression of a Large Gene Pool: Identification of a Gene Program for Acquired Neuroprotection Induced by Synaptic Activity
Synaptic activity can boost neuroprotection through a mechanism that requires synapse-to-nucleus communication and calcium signals in the cell nucleus. Here we show that in hippocampal neurons nuclear calcium is one of the most potent signals in neuronal gene expression. The induction or repression of 185 neuronal activity-regulated genes is dependent upon nuclear calcium signaling. The nuclear calcium-regulated gene pool contains a genomic program that mediates synaptic activity-induced, acquired neuroprotection. The core set of neuroprotective genes consists of 9 principal components, termed Activity-regulated Inhibitor of Death (AID) genes, and includes Atf3, Btg2, GADD45β, GADD45γ, Inhibin β-A, Interferon activated gene 202B, Npas4, Nr4a1, and Serpinb2, which strongly promote survival of cultured hippocampal neurons. Several AID genes provide neuroprotection through a common process that renders mitochondria more resistant to cellular stress and toxic insults. Stereotaxic delivery of AID gene-expressing recombinant adeno-associated viruses to the hippocampus confers protection in vivo against seizure-induced brain damage. Thus, treatments that enhance nuclear calcium signaling or supplement AID genes represent novel therapies to combat neurodegenerative conditions and neuronal cell loss caused by synaptic dysfunction, which may be accompanied by a deregulation of calcium signal initiation and/or propagation to the cell nucleus
Day hospital Mentalization-based treatment versus intensive outpatient Mentalization-based treatment for patients with severe borderline personality disorder: protocol of a multicentre randomized clinical trial
BACKGROUND: Borderline personality disorder (BPD) is associated with a high socioeconomic burden. Although a number of evidence-based treatments for BPD are currently available, they are not widely disseminated; furthermore, there is a need for more research concerning their efficacy and cost-effectiveness. Such knowledge promises to lead to more efficient use of resources, which will facilitate the effective dissemination of these costly treatments. This study focuses on the efficacy and cost-effectiveness of Mentalization-Based Treatment (MBT), a manualized treatment for patients with BPD. Studies to date have either investigated MBT in a day hospitalization setting (MBT-DH) or MBT offered in an intensive outpatient setting (MBT-IOP). No trial has compared the efficacy and cost-effectiveness of these MBT programmes. As both interventions differ considerably in terms of intensity of treatment, and thus potentially in terms of efficacy and cost-effectiveness, there is a need for comparative trials. This study therefore sets out to investigate the efficacy and cost-effectiveness of MBT-DH versus MBT-IOP in patients with BPD. A secondary aim is to investigate the association between baseline measures and outcome, which might improve treatment selection and thus optimize efficacy and cost-effectiveness. METHODS/DESIGN: A multicentre randomized controlled trial comparing MBT-DH versus MBT-IOP in severe BPD patients. Patients are screened for BPD using the Structured Clinical Interview for DSM-IV Axis II Personality Disorders, and are assessed before randomization, at the start of treatment and 6, 12, 18, 24, 30 and 36 months after the start of treatment. Patients who refuse to participate will be offered care as usual in the same treatment centre. The primary outcome measure is symptom severity as measured by the Brief Symptom Inventory. Secondary outcome measures include parasuicidal behaviour, depression, substance use, social, interpersonal, and personality functioning, attachment, mentalizing capacities, and quality of life. All analyses will be conducted based on the intention-to-treat principle. Cost-effectiveness will be calculated based on costs per quality-adjusted life-year. DISCUSSION: This multisite randomized trial will provide data to refine criteria for treatment selection for severe BPD patients and promises to optimize (cost-)effectiveness of the treatment of BPD patients. TRIAL REGISTRATION: NTR2292. Registered 16 April 2010
The effect of regular walks on various health aspects in older people with dementia: protocol of a randomized-controlled trial
<p>Abstract</p> <p>Background</p> <p>Physical activity has proven to be beneficial for physical functioning, cognition, depression, anxiety, rest-activity rhythm, quality of life (QoL), activities of daily living (ADL) and pain in older people. The aim of this study is to investigate the effect of walking regularly on physical functioning, the progressive cognitive decline, level of depression, anxiety, rest-activity rhythm, QoL, ADL and pain in older people with dementia.</p> <p>Methods/design</p> <p>This study is a longitudinal randomized controlled, single blind study. Ambulatory older people with dementia, who are regular visitors of daily care or living in a home for the elderly or nursing home in the Netherlands, will be randomly allocated to the experimental or control condition. Participants of the experimental group make supervised walks of 30 minutes a day, 5 days a week, as part of their daily nursing care. Participants of the control group will come together three times a week for tea or other sedentary activities to control for possible positive effects of social interaction. All dependent variables will be assessed at baseline and after 6 weeks, and 3, 6, 9, 12 and 18 months of intervention.</p> <p>The dependent variables include neuropsychological tests to assess cognition, physical tests to determine physical functioning, questionnaires to assess ADL, QoL, level of depression and anxiety, actigraphy to assess rest-activity rhythm and pain scales to determine pain levels. Potential moderating variables at baseline are: socio-demographic characteristics, body mass index, subtype of dementia, apolipoprotein E (ApoE) genotype, medication use and comorbidities.</p> <p>Discussion</p> <p>This study evaluates the effect of regular walking as a treatment for older people with dementia. The strength of this study is that 1) it has a longitudinal design with multiple repeated measurements, 2) we assess many different health aspects, 3) the intervention is not performed by research staff, but by nursing staff which enables it to become a routine in usual care. Possible limitations of the study are that 1) only active minded institutions are willing to participate creating a selection bias, 2) the drop-out rate will be high in this population, 3) not all participants will be able to perform/understand all tests.</p> <p>Trial registration</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1482">NTR1482</a></p
The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae)
Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species—drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit conservation and restocking efforts and help fine-tune mariculture techniques. Understanding the repertoire of giant clam behaviours will also facilitate the prediction of threshold levels for sustainable exploitation as well as recovery rates of depleted clam populations
Connecting physical and social dimensions of place attachment: What can we learn from attachment to urban recreational spaces?
Identifying an indoor air exposure limit for formaldehyde considering both irritation and cancer hazards
Formaldehyde is a well-studied chemical and effects from inhalation exposures have been extensively characterized in numerous controlled studies with human volunteers, including asthmatics and other sensitive individuals, which provide a rich database on exposure concentrations that can reliably produce the symptoms of sensory irritation. Although individuals can differ in their sensitivity to odor and eye irritation, the majority of authoritative reviews of the formaldehyde literature have concluded that an air concentration of 0.3 ppm will provide protection from eye irritation for virtually everyone. A weight of evidence-based formaldehyde exposure limit of 0.1 ppm (100 ppb) is recommended as an indoor air level for all individuals for odor detection and sensory irritation. It has recently been suggested by the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the US Environmental Protection Agency (US EPA) that formaldehyde is causally associated with nasopharyngeal cancer (NPC) and leukemia. This has led US EPA to conclude that irritation is not the most sensitive toxic endpoint and that carcinogenicity should dictate how to establish exposure limits for formaldehyde. In this review, a number of lines of reasoning and substantial scientific evidence are described and discussed, which leads to a conclusion that neither point of contact nor systemic effects of any type, including NPC or leukemia, are causally associated with exposure to formaldehyde. This conclusion supports the view that the equivocal epidemiology studies that suggest otherwise are almost certainly flawed by identified or yet to be unidentified confounding variables. Thus, this assessment concludes that a formaldehyde indoor air limit of 0.1 ppm should protect even particularly susceptible individuals from both irritation effects and any potential cancer hazard
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