bluuebunny/crossref_metadata_2025_split huggingface dataset:
Island biogeography of Caribbean coral reef fish
Authors: Sandin Stuart A. , Vermeij Mark J. A. , Hurlbert Allen H. 
Published: September 2008

ABSTRACTAim  The goal of our study was to test fundamental predictions of biogeographical theories in tropical reef fish assemblages, in particular relationships between fish species richness and island area, isolation and oceanographic variables (temperature and productivity) in the insular Caribbean. These analyses complement an analogous and more voluminous body of work from the tropical Indo‐Pacific. The Caribbean is more limited in area with smaller inter‐island distances than the Indo‐Pacific, providing a unique context to consider fundamental processes likely to affect richness patterns of reef fish.Location  Caribbean Sea.Methods  We compiled a set of data describing reef‐associated fish assemblages from 24 island nations across the Caribbean Sea, representing a wide range of isolation and varying in land area from 53 to 110,860 km2. Regression‐based analyses compared the univariate and combined effects of island‐specific physical predictors on fish species richness.Results  We found that diversity of reef‐associated fishes increases strongly with increasing island area and with decreasing isolation. Richness also increases with increasing nearshore productivity. Analyses of various subsets of the entire data set reveal the robustness of the richness data and biogeographical patterns.Main conclusions  Within the relatively small and densely packed Caribbean basin, fish species richness fits the classical species–area relationship. Richness also was related negatively to isolation, suggesting direct effects of dispersal limitation in community assembly. Because oceanic productivity was correlated with isolation, however, the related effects of system‐wide productivity on richness cannot be disentangled. These results highlight fundamental mechanisms that underlie spatial patterns of biodiversity among Caribbean coral reefs, and which are probably also are functioning in the more widespread and heterogeneous reefs of the Indo‐Pacific.
Simulating vegetation shifts in north‐eastern Mediterranean mountain forests under climatic change scenarios
Authors: Fyllas Nikolaos M. , Troumbis Andreas Y. 
Published: September 2008

ABSTRACTAim  To explore potential shifts in vegetation and fire regime in some dominant forest types in the north‐eastern part of the Mediterranean basin under climate change.Location  Two altitudinal gradients in the continental part of Greece.Methods  We developed a forest gap dynamics simulator that provides feedback from the stand to its water balance and flammability status. The model is used to simulate vegetation dynamics in two mountainous areas, currently found under different aridity conditions. Two climatic change scenarios (Intergovernmental Panel on Climate Change A1 and B2) were applied to explore differences in the response of the established forest types. In addition we explicitly accounted for the role of fire, under both current and altered climate patterns.Results  Fire was identified to play a significant role in low‐altitude sites. Its significance increased with the severity of the climate change scenario. Elevational shifts of the dominant species were simulated for each site, while in some cases these changes were associated with a shorter fire cycle and a frequent resetting of processes of vegetation change.Main conclusions  Our simulations suggest a greater vulnerability of mountainous Mediterranean drier areas regarding compositional alteration and flammability trends. Changes in vegetation could take place through both a discrete and synergistic realization of changes in the drought stress and fire frequency.
Hypotheses, mechanisms and trade‐offs of tolerance and adaptation to serpentine soils: from species to ecosystem level
Authors: Kazakou E. , Dimitrakopoulos P. G. , Baker A. J. M. , Reeves R. D. , Troumbis A. Y. 
Published: September 2008

AbstractUnderstanding the relative importance of the abiotic environment and species interactions in determining the distribution and abundance of organisms has been a challenge in ecological research. Serpentine substrata are stressful environments for plant growth due to multiple limitations, collectively called the “serpentine syndrome”. In the present review, our aim is not only to describe recent work in serpentine ecology, but also to highlight specific mechanisms of species tolerance and adaptation to serpentine soils and their effects on community structure and ecosystem functioning. We present hypotheses of the development of serpentine endemism and a description of functional traits of serpentine plants together with a synthesis of species interactions in serpentine soils and their effects on community structure and ecosystem productivity. In addition, we propose hypotheses about the effects of the ‘serpentine syndrome’ on ecosystem processes including productivity and decomposition.
Neural activity and diurnal variation of cortisol: Evidence from brain electrical tomography analysis and relevance to anhedonia
Authors: Putnam Katherine M. , Pizzagalli Diego A. , Gooding Diane C. , Kalin Ned H. , Davidson Richard J. 
Published: September 2008

AbstractThe medial prefrontal cortex (mPFC), hippocampus, and amygdala are implicated in the regulation of affect and physiological processes, including hypothalamic‐pituitary‐adrenal (HPA) axis function. Anhedonia is likely associated with dysregulation of these processes. Dense‐array resting electroencephalographic and cortisol were obtained from healthy and anhedonic groups. Low‐resolution electromagnetic tomography was used to compute intracerebral current density. For the control group, voxelwise analyses found a relationship between current density in beta and gamma bands and steeper cortisol slope (indicative of more adaptive HPA axis functioning) in regions of the hippocampus, parahippocampal gyrus, and mPFC. For the anhedonic group, the mPFC finding was absent. Anhedonia may be characterized by disruptions of mPFC‐mediated neuroendocrine regulation, which could constitute a vulnerability to the development of stress‐related disorders.
Modality‐specific attentional startle modulation during continuous performance tasks: A brief time is sufficient
Authors: Alhadad Sakinah S.J. , Lipp Ottmar V. , Purkis Helena M. 
Published: September 2008

AbstractAttentional startle modulation has been found to be modality specific in continuous performance tasks (CPTs) and modality nonspecific in trial‐structured tasks. Experiment 1 investigated whether attentional blink modulation in a CPT would change if a trial structure was imposed. Participants performed a visual CPT either continuously (CONT), or during brief periods of time signaled by a change in screen color with stimuli either presented all the time (MIXED) or only during the trial segments (DISC). Contrary to expectation, evidence for modality‐specific attentional startle modulation—smaller acoustic startle during targets than during nontargets—was strongest in Groups MIXED and DISC. Experiment 2 confirmed that this pattern of results was present during the first stimulus of the task period in group DISC. This suggests that the continuous nature of a task is not critical in determining the attentional mechanisms engaged.
Psychiatric and neurophysiological predictors of obesity in HIV/AIDS
Authors: Bauer Lance O. 
Published: September 2008

AbstractThe objective of the study was to identify predictors of obesity. One hundred eleven nonobese and 48 obese HIV‐1 seropositive patients provided information on medical history and other characteristics. They were then asked to detect the passage of 2‐s time intervals while the contingent negative variation (CNV) was recorded. Obese patients were healthier, more likely to be receiving Highly Active Antiretroviral Therapy, and less likely to be substance dependent. Obese patients also exhibited a greater CNV slope and responded prematurely. A path model suggested that CD4+count and protease inhibitor use directly predicted obesity. Depression had no direct effect. However, when incorporated into a hypothetical construct, “mood dysregulation,” that also included childhood conduct problems and stimulant dependence, the shared variance among the indicators did predict obesity. This relationship was mediated through premature response preparation (anterior scalp CNV amplitude) and its hypothesized association with impatience/impulsivity.
Modulation of the human mirror neuron system during cognitive activity
Authors: Muthukumaraswamy Suresh D. , Singh Krish D. 
Published: September 2008

AbstractIn this experiment we examined the relationship between the mirror neuron system and increased attention caused by task demands. Whole head MEG recordings were made from 13 participants who were asked to passively observe finger movement sequences, observe these sequences with the knowledge they would later have to perform the sequence presented, and finally, to perform a nonmotor mathematics task based on the finger‐movement sequences. Beta‐band (15–35 Hz) sensorimotor desynchronization was found in overlapping areas during passive observation and in a separate motor execution condition, indicating the activity of the human mirror neuron system. The beta desynchronization in these areas was enhanced relative to passive viewing when participants had to watch the stimuli to later imitate and when they performed the mathematics task, indicating that mirror neuron system activity can be modulated by attention.
Cardiovascular dynamics in blood phobia: Evidence for a key role of sympathetic activity in vulnerability to syncope
Authors: Sarlo Michela , Buodo Giulia , Munafò Marianna , Stegagno Luciano , Palomba Daniela 
Published: September 2008

AbstractThis study was aimed at clarifying the mechanism predisposing people with blood phobia to syncope by investigating the complete hemodynamic response pattern and the underlying autonomic control. Blood phobics and controls were shown 3 film‐clips: phobia‐related, phobia‐unrelated, and neutral. Hemodynamic responses were recorded using impedance cardiography and Finapres. Preejection period and respiratory sinus arrhythmia were employed as indices of cardiac sympathetic and parasympathetic activity. Self‐ratings of emotion were also collected. Blood phobics displayed global heart rate and cardiac output increases to the phobic film, mediated by augmented cardiac sympathetic activity. Systolic blood pressure and total peripheral resistance markedly declined, with no evidence of diphasic reaction or parasympathetic activation. An impaired vasomotor response under sympathetic control might be the key mechanism underlying the phobic dysfunctional response.
Affective modulation of inspiratory motor drive
Authors: Van Diest Ilse , Janssens Thomas , Bogaerts Katleen , Fannes Stien , Davenport Paul W. , Van Den Bergh Omer 
Published: September 2008

AbstractThe present study aimed to explore inspiratory motor drive as measured by inspiratory occlusion pressure (P100) during affective picture viewing. P100 is the decrease in mouth pressure that develops 100 ms after an inspiratory effort against a closed breathing circuit. The P100 is a measure of the “central respiratory drive.” Seventy‐eight healthy women viewed four pictures series (160 s) varying in content: neutral, positive, threat, or pain. They also rated each picture series on pleasantness and arousal. An occlusion was applied at the onset of inspiration in 33% of the breaths. The threat and the pain picture series were associated with an increased P100 and were rated as most unpleasant and highest in arousal. We conclude that inspiratory motor drive is affectively modulated and is a measure of the respiratory response to threatful stimuli.
Dopaminergic system dysregulation in the mrsk2_KO mouse, an animal model of the Coffin‐Lowry syndrome
Authors: Marques Pereira Patricia , Gruss Michael , Braun Katharina , Foos Nicolas , Pannetier Solange , Hanauer André 
Published: September 2008

AbstractThe Coffin‐Lowry syndrome, a rare syndromic form of X‐linked mental retardation, is caused by loss‐of‐function mutations in the hRSK2 (RPS6KA3) gene. To further investigate RSK2 (90‐kDa ribosomal S6 kinase) implication in cognitive processes, a mrsk2_KO mouse has previously been generated as an animal model of Coffin‐Lowry syndrome. The aim of the present study was to identify possible neurochemical dysregulation associated with the behavioral and morphological abnormalities exhibited by mrsk2_KO mice. A cortical dopamine level increase was found in mrsk2_KO mice that was accompanied by an over‐expression of dopamine receptor of type 2 and the dopamine transporter. We also detected an increase of total and phosphorylated extracellular regulated kinase that may be responsible for the increased level of tyrosine hydroxylase phosphorylation also observed. By taking into consideration previously reported data, our results strongly suggest that the dopaminergic dysregulation in mrsk2_KO mice may be caused, at least in part, by tyrosine hydroxylase hyperactivity. This cortical hyperdopaminergia may explain some non‐cognitive but also cognitive alterations exhibited by mrsk2_KO mice.
An antagonistic interaction between A2Badenosine and D2dopamine receptors modulates the function of rat carotid body chemoreceptor cells
Authors: Conde Silvia V. , Gonzalez Constancio , Batuca Joana R. , Monteiro Emilia C. , Obeso Ana 
Published: September 2008

AbstractWe have previously demonstrated that adenosine controls the release of catecholamines (CA) from carotid body (CB) acting on A2Breceptors. Here, we have tested the hypothesis that the control is exerted via an interaction between adenosine A2Band dopamine D2receptors present in chemoreceptor cells. Experiments were performedin vitroin CB from 3 months rats. The effect of A2Badenosine and D2dopamine agonists and antagonists applied alone or in combination were studied on basal (20%O2) and hypoxia (10%O2)‐evoked release of CA and cAMP content of CB. We have found that adenosine A2agonists and D2antagonists dose‐dependently increased basal and evoked release CA from the CB while A2antagonists and D2agonists had an inhibitory action. The existence of A2B‐D2receptor interaction was established because the inhibitory action of A2antagonists was abolished by D2antagonists, and the stimulatory action of A2agonists was abolished by D2agonists. Further, A2agonists increased and D2agonist decreased cAMP content in the CB; their co‐application eliminated the response. The present results provide direct pharmacological evidence that an antagonistic interaction between A2Badenosine and D2dopamine receptors exist in rat CB and would explain the dopamine‐adenosine interactions on ventilation previously observed.
Persistent MDMA‐induced dopaminergic neurotoxicity in the striatum and substantia nigra of mice
Authors: Granado Noelia , O’Shea Esther , Bove Jordi , Vila Miquel , Colado Mª Isabel , Moratalla Rosario 
Published: September 2008

AbstractAcute administration of repeated doses of 3,4‐methylenedioxymethamphetamine (MDMA, ecstasy) dramatically reduces striatal dopamine (DA) content, tyrosine hydroxylase (TH), and DA transporter‐immunoreactivity in mice. In this study, we show for the first time the spatiotemporal pattern of dopaminergic damage and related molecular events produced by MDMA administration in mice. Our results include the novel finding that MDMA produces a significant decrease in the number of TH‐immunoreactive neurons in the substantia nigra (SN). This decrease appears 1 day after injection, remains stable for at least 30 days, and is accompanied by a dose‐dependent long‐lasting decrease in TH‐ and DA transporter‐immunoreactivity in the striatum, which peaked 1 day after treatment and persisted for at least 30 days, however, some recovery was evident from day 3 onwards, evidencing sprouting of TH fibers. No change is observed in the NAc indicating that MDMA causes selective destruction of DA‐containing neurons in the nigrostriatal pathway, sparing the mesolimbic pathway. The expression of Mac‐1 increased 1 day after MDMA treatment and glial fibrillary acidic protein increased 3 days post‐treatment in the striatum and SN but not in the NAc, in strict anatomical correlation with dopaminergic damage. These data provide the first evidence that MDMA causes persistent loss of dopaminergic cell bodies in the SN.
Health status, symptoms and health counselling among middle‐aged men: comparison of men at low and high risk
Authors: Näslindh‐Ylispangar Anita , Sihvonen Marja , Sarna Seppo , Kekki Pertti 
Published: September 2008

Aim:  To assess the levels of health indicators, health behaviour and health counselling among men at low and high risk for adverse health outcomes.Methods:  A total of 273 middle‐aged men, 145 at low and 128 at high risk for adverse health outcomes, were studied. Two‐ and three‐way tables with chi‐squared tests were performed to identify differences between the groups. A step‐wise logistic regression model was used to analyse symptoms and complaints associated with the likelihood of perceived health.Results:  One‐half of the low‐risk men were overweight, of whom 8% were obese. Forty per cent of the low‐risk men smoked cigarettes and one‐fifth used alcohol excessively. Headache, chest and back pain, stress, and insomnia occurred frequently (range: 20–38%) and were highly correlated with depression. Joint pain (p = 0.012) in the low‐risk men and sciatica (p = 0.047) in the high‐risk men were the only statistically significant differences related to normal weight vs. overweight status. There was a greater than sixfold odds of average/poor health among low‐risk men who were depressed than in those who were not depressed men. Only a small percentage of the low‐risk men had received counselling from professionals for different health issues, including weight control and smoking cessation; the corresponding percentages were somewhat higher when given by family members.Conclusions:  A real need for better counselling was found among middle‐aged men identified with obesity and risky behaviours. Public health nurses and other health workers should be aware of the differences between men at low and high risk. Men had different health experiences and lifestyles in these groups. More research is needed to determine the most efficient counselling strategies among men.
Effects of State Minimum Staffing Standards on Nursing Home Staffing and Quality of Care
Authors: Park Jeongyoung , Stearns Sally C. 
Published: September 2008

Objective. To investigate the impact of state minimum staffing standards on the level of staffing and quality of nursing home care.Data Sources. Online Survey and Certification Reporting System (OSCAR) merged with the Area Resource File from 1998 through 2001.Study Design. Between 1998 and 2001, 16 states implemented or expanded staffing standards in excess of federal requirements, creating a natural experiment in comparison with facilities in states without new standards. Difference‐in‐differences models using facility fixed effects were estimated to determine the effect of state standards.Data Collection/Extraction Methods. OSCAR data were linked to the data on market conditions and state policies. A total of 55,248 facility‐year observations from 15,217 freestanding facilities were analyzed.Principal Findings. Increased standards resulted in small staffing increases for facilities with staffing initially below or close to new standards. Yet the standards were associated with reductions in restraint use and the number of total deficiencies at all types of facilities.Conclusions. Mandated staffing standards affect only low‐staff facilities facing potential for penalties, and effects are small. Selected facility‐level outcomes may show improvement at all facilities due to a general response to increased standards or to other quality initiatives implemented at the same time as staffing standards.
Transportation Brokerage Services and Medicaid Beneficiaries' Access to Care
Authors: Kim Jinkyung , Norton Edward C. , Stearns Sally C. 
Published: September 2008

Objective. To examine the effect of capitated transportation brokerage services on Medicaid beneficiaries' access to care and expenditures.Data Sources/Study Setting. The study period from 1996 to 1999 corresponds to the period of a natural experiment during which Georgia and Kentucky implemented transportation brokerage services. Effects were estimated for asthmatic children and diabetic adults.Study Design. We used difference‐in‐differences models to assess the effects of transportation brokerage services on access to care, measured by Medicaid expenditures and health services use. The study design is strengthened by the staggered implementation dates between states and within each state.Principal Findings. For asthmatic children, transportation brokerage services increased nonemergency transportation expenditures and the likelihood of using any services; reductions in monthly expenditures more than offsetting the increased transportation costs. For diabetic adults, nonemergency transportation costs decreased despite increased monthly use of health services; average monthly medical expenditures and the likelihood of hospital admission for an ambulatory care‐sensitive condition (ACSC) also decreased.Conclusions. The shift to transportation brokerage services improved access to care among Medicaid beneficiaries and decreased the expenditures. The increase in access combined with reduced hospitalizations for asthmatic children and ACSC admissions for diabetic adults are suggestive of improvements in health outcomes.
Corporate Governance and Agency Conflicts
Authors: DEY AIYESHA 
Published: September 2008

ABSTRACTI investigate whether corporate governance is associated with the level of agency conflicts in firms. I employ exploratory principal components analysis on 22 individual governance variables to obtain seven factors that represent the different dimensions of governance for a firm. I measure the level of agency conflicts in firms based on seven proxies for agency conflicts used in the literature. I find that firms with greater agency conflicts have better governance mechanisms in place, particularly those related to the board, audit committee, and auditor. I also find that the composition and functioning of the board, the independence of the auditor, and the equity‐based compensation of directors are significantly associated with firm performance, but primarily for firms with high agency conflicts. Overall, the results support the theory that the existence and role of various governance mechanisms in a firm are a function of the level of agency conflicts in the firm.