Patterns of plant phenology in Amazonian seasonally flooded and unflooded forests

Few studies have successfully monitored community-wide phenological patterns in seasonally flooded Amazonian várzea forests, where a prolonged annual flood pulse arguably generates the greatest degree of seasonality of any low-latitude ecosystem on Earth. We monitored the vegetative and reproductive plant phenology of várzea (VZ) floodplain and adjacent terra firme (TF) forests within two contiguous protected areas in western Brazilian Amazonia, using three complementary methods: monthly canopy observations of 1056 individuals (TF: 556, VZ: 500), twice monthly collections from 0.5-m2 litterfall traps within two 100-ha plots (1 TF, 1 VZ; 96 traps per plot), and monthly ground surveys of residual fruit-fall along transect-grids within each 100-ha plot (12 km per plot). Surveys encompassed the entire annual flood cycle and employed a floating trap design to cope with fluctuating water levels. Phenology patterns were generally similar in both forest types. Leaffall peaked during the aquatic phase in várzea forest and the dry season in terra firme. Flowering typically followed leaffall and leaf flush, extending into the onset of the terrestrial phase and rainy season in várzea and terra firme, respectively. Abiotic seed dispersal modes were relatively more prevalent in várzea than terra firme; the main contrast in fruiting seasonality was more likely a result of differences in community composition and relative abundance of seed dispersal modes than differences within individual genera. We emphasize the difficulty in distinguishing the role of the flood pulse from other seasonal environmental variables without multiannual data or spatially replicated studies across the spectrum of Amazonian forest types

INTEGRAL/RossiXTE high-energy observation of a state transition of GX 339-4

On 2004 August 15, we observed a fast (shorter than 10 hours) state transition in the bright black-hole transient GX 339-4 simultaneously with RossiXTE and INTEGRAL. This transition was evident both in timing and spectral properties. Combining the data from PCA, HEXTE and IBIS, we obtained good quality broad-band (3-200 keV) energy spectra before and after the transition. These spectra indicate that the hard component steepened. Also, the high-energy cutoff that was present at ~70 keV before the transition was not detected after the transition. This is the first time that an accurate determination of the broad-band spectrum across such a transition has been measured on a short time scale. It shows that, although some spectral parameters do not change abruptly through the transition, the high-energy cutoff increases/disappears rather fast. These results constitute a benchmark on which to test theoretical models for the production of the hard component in these systems.Comment: Accepted for publication in MNRAS (9 pages, 6 figures

Patients with multiple sclerosis do not necessarily consume more alcohol or tobacco than the general population

Peer reviewedPublisher PD

Decreasing sprint duration from 20 to 10 s during reduced-exertion high-intensity interval training (REHIT) attenuates the increase in maximal aerobic capacity but has no effect on affective and perceptual responses

Purpose: Recent studies have demonstrated that modifying the ‘classic’ 6x30-s ‘all-out’ sprint interval training (SIT) protocol by incorporating either shorter sprints (6x10-s or 15-s sprints) or fewer sprints (e.g. 2x20-s sprints; reduced-exertion high-intensity interval training (REHIT)) does not attenuate the training-induced improvements in maximal aerobic capacity (V̇O2max). The aim of the present study was to determine whether reducing the sprint duration in the REHIT protocol from 20 s to 10 s per sprint influences acute affective responses and the change in V̇O2max following training. Methods: Thirty-six sedentary or recreationally active participants (17 women; mean±SD age: 22±3 y, BMI: 24.5±4.6 kg·m-2, V̇O2max: 37±8 mL·kg-1·min-1) were randomised to a group performing a ‘standard’ REHIT protocol involving 2x20-s sprints or a group who performed 2x10-s sprints. V̇O2max was determined before and after 6 weeks of 3 weekly training sessions. Acute affective responses and perceived exertion were assessed during training. Results: Greater increases in V̇O2max were observed for the group performing 20-s sprints (2.77±0.75 to 3.04±0.75 L·min-1; +10%) compared to the group performing 10-s sprints (2.58±0.57 vs. 2.67±3.04 L·min-1; +4%; group×time interaction effect: p<0.05; d=1.06). Positive affect and the mood state vigour increased post-exercise, while tension, depression and total mood disturbance decreased, and negative affect remained unchanged. Affective responses and perceived exertion were not altered by training and were not different between groups. Conclusion: Reducing sprint duration in the REHIT protocol from 20 s to 10 s attenuates improvements in V̇O2max, and does not result in more positive affective responses or lower perceived exertion

Elevated cerebrospinal fluid 5-hydroxyindoleacetic acid in macaques following early life stress and inverse association with hippocampal volume: preliminary implications for serotonin-related function in mood and anxiety disorders

Background: Early life stress (ELS) is cited as a risk for mood and anxiety disorders, potentially through altered serotonin neurotransmission. We examined the effects of ELS, utilizing the variable foraging demand (VFD) macaque model, on adolescent monoamine metabolites. We sought to replicate an increase in cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) observed in two previous VFD cohorts. We hypothesized that elevated cisternal 5-HIAA was associated with reduced neurotrophic effects, conceivably due to excessive negative feedback at somatodendritic 5-HT1A autoreceptors. A putatively decreased serotonin neurotransmission would be reflected by reductions in hippocampal volume and white matter (WM) fractional anisotropy (FA).Methods: When infants were 2-6 months of age, bonnet macaque mothers were exposed to VFD. We employed cisternal CSF taps to measure monoamine metabolites in VFD (N = 22) and non-VFD (N = 14) offspring (mean age = 2.61 years). Metabolites were correlated with hippocampal volume obtained by MRI and WM FA by diffusion tensor imaging in young adulthood in 17 males [10 VFD (mean age = 4.57 years)].Results: VFD subjects exhibited increased CSF 5-HIAA compared to non-VFD controls. An inverse correlation between right hippocampal volume and 5-HIAA was noted in VFD- but not controls. CSF HVA and MHPG correlated inversely with hippocampal volume only in VFD. CSF 5-HIAA correlated inversely with FA of the VVM tracts of the anterior limb of the internal capsule (ALIC) only in VFD.Conclusions: Elevated cisternal 5-HIAA in VFD may reflect increased dorsal raphe serotonin, potentially inducing excessive autoreceptor activation, inducing a putative serotonin deficit in terminal fields. Resultant reductions in neurotrophic activity are reflected by smaller right hippocampal volume. Convergent evidence of reduced neurotrophic activity in association with high CSF 5-HIAA in VFD was reflected by reduced FA of the ALIC.NIMHSuny Downstate Med Ctr, Nonhuman Primate Lab, Dept Psychiat & Behav Sci, Brooklyn, NY 11203 USANew York State Psychiat Inst & Hosp, New York, NY 10032 USASuny Downstate Med Ctr, Coll Med, Brooklyn, NY 11203 USAUniversidade Federal de São Paulo, Dept Psychiat & Neuroradiol, São Paulo, BrazilFranklin Beha Hlh Consultants, Bronx, NY USANew York State Psychiat Inst & Hosp, Dept Mol Imaging & Neuropathol, New York, NY 10032 USAIcahn Sch Med Mt Sinai, Dept Psychiat, New York, NY 10029 USAIcahn Sch Med Mt Sinai, Dept Neurosci, New York, NY 10029 USAIcahn Sch Med Mt Sinai, Dept Radiol, New York, NY 10029 USAIcahn Sch Med Mt Sinai, Fishberg Dept Neurosci, New York, NY 10029 USAIcahn Sch Med Mt Sinai, Friedman Brain Inst, New York, NY 10029 USAYale Univ, Sch Med, Dept Psychiat, New Haven, CT USAMichael E Debakey VA Med Ctr, Mental Hlth Care Line, Houston, TX USABaylor Coll Med, Menninger Dept Psychiat & Behav Sci, Houston, TX 77030 USAYale Univ, Sch Med, Ctr Child Study, New Haven, CT 06510 USAUniversidade Federal de São Paulo, Dept Psychiat & Neuroradiol, São Paulo, BrazilNIMH: R21MH066748NIMH: R01 MH059990Web of Scienc

The role of the chemokine receptor CXCR4 in infection with feline immunodeficiency virus

Infection with feline immunodeficiency virus (FIV) leads to the development of a disease state similar to AIDS in man. Recent studies have identified the chemokine receptor CXCR4 as the major receptor for cell culture-adapted strains of FIV, suggesting that FIV and human immunodeficiency virus (HIV) share a common mechanism of infection involving an interaction between the virus and a member of the seven transmembrane domain superfamily of molecules. This article reviews the evidence for the involvement of chemokine receptors in FIV infection and contrasts these findings with similar studies on the primate lentiviruses HIV and SIV (simian immunodeficiency virus)

PRODH Polymorphisms, Cortical Volumes and Thickness in Schizophrenia

Schizophrenia is a neurodevelopmental disorder with high heritability. Several lines of evidence indicate that the PRODH gene may be related to the disorder. Therefore, our study investigates the effects of 12 polymorphisms of PRODH on schizophrenia and its phenotypes. To further evaluate the roles of the associated variants in the disorder, we have conducted magnetic resonance imaging (MRI) scans to assess cortical volumes and thicknesses. A total of 192 patients were evaluated using the Structured Clinical Interview for DSM-IV (SCID), Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale, Global Assessment of Functioning (GAF) and Clinical Global Impression (CGI) instruments. the study included 179 controls paired by age and gender. the samples were genotyped using the real-time polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP)-PCR and Sanger sequencing methods. A sample of 138 patients and 34 healthy controls underwent MRI scans. One polymorphism was associated with schizophrenia (rs2904552), with the G-allele more frequent in patients than in controls. This polymorphism is likely functional, as predicted by PolyPhen and SIFT, but it was not associated with brain morphology in our study. in summary, we report a functional PRODH variant associated with schizophrenia that may have a neurochemical impact, altering brain function, but is not responsible for the cortical reductions found in the disorder.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo UNIFESP, Disciplina Genet, Dept Morfol & Genet, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, LiNC, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Psiquiatria, São Paulo, BrazilFac Med ABC FMABC, Dept Ginecol & Obstet, Disciplina Genet & Reprod Humana, São Paulo, BrazilFed Univ Para, Lab Genet Humana & Med, BR-66059 Belem, Para, BrazilUniv Fed ABC, Ctr Math Computat & Cognit, Santo Andre, BrazilUniversidade Federal de São Paulo UNIFESP, Disciplina Genet, Dept Morfol & Genet, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, LiNC, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Psiquiatria, São Paulo, BrazilFAPESP: 2011/50740-5FAPESP: 2007/58736-1Web of Scienc

Heterogeneity in genetic admixture across different regions of Argentina

The population of Argentina is the result of the intermixing between several groups, including Indigenous American, European and African populations. Despite the commonly held idea that the population of Argentina is of mostly European origin, multiple studies have shown that this process of admixture had an impact in the entire Argentine population. In the present study we characterized the distribution of Indigenous American, European and African ancestry among individuals from different regions of Argentina and evaluated the level of discrepancy between self-reported grandparental origin and genetic ancestry estimates. A set of 99 autosomal ancestry informative markers (AIMs) was genotyped in a sample of 441 Argentine individuals to estimate genetic ancestry. We used non-parametric tests to evaluate statistical significance. The average ancestry for the Argentine sample overall was 65% European (95%CI: 63-68%), 31% Indigenous American (28-33%) and 4% African (3-4%). We observed statistically significant differences in European ancestry across Argentine regions [Buenos Aires province (BA) 76%, 95%CI: 73-79%; Northeast (NEA) 54%, 95%CI: 49-58%; Northwest (NWA) 33%, 95%CI: 21-41%; South 54%, 95%CI: 49-59%; p<0.0001] as well as between the capital and immediate suburbs of Buenos Aires city compared to more distant suburbs [80% (95%CI: 75-86%) versus 68% (95%CI: 58-77%), p = 0.01]. European ancestry among individuals that declared all grandparents born in Europe was 91% (95%CI: 88-94%) compared to 54% (95%CI: 51-57%) among those with no European grandparents (p<0.001). Our results demonstrate the range of variation in genetic ancestry among Argentine individuals from different regions in the country, highlighting the importance of taking this variation into account in genetic association and admixture mapping studies in this population

Crisis in neuroimaging: is neuroimaging failing 15 years after the decade of the brain?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Sao Paulo UNIFESP, Dept Psiquiatria, Lab Interdisciplinar Neurociencias Clin LiNC, Sao Paulo, SP, BrazilUniv Fed ABC, Ctr Matemat Comp & Cognicao, Santo Andre, SP, BrazilLaboratório Interdisciplinar de Neurociências Clínicas (LiNC), Departamento de Psiquiatria, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP BrazilFAPESP: 2013/10498-6FAPESP: 2013/00506-1FAPESP: 2013/08531-5CNPq: 442026/2014-5CNPq: 312984/2014-6Web of Scienc

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise.

addresses: Health and Biology, Liverpool Hope University, Liverpool, UK. [email protected]: Comparative Study; Journal ArticleThis is an Author's Accepted Manuscript of an article published in Journal of Sports Sciences, 2008, Vol. 26, Issue 10, pp. 1081 – 1090 © 2008 copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/02640410801930200Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g kg body mass(-1) of glutamine in 5 ml kg body mass(-1) placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO(2) = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake (VO(2max)) immediately before completing a brief high-intensity time-trial (approximately 4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (DeltaVO(2max), P = 0.02) and exercise performance (control: 243 s, s(x) = 7; glutamine: 242 s, s(x) = 3; hyperoxia: 231 s, s(x) = 3; hyperoxia + glutamine: 228 s, s(x) = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased DeltaVO(2max) in normoxia, but not hyperoxia (interaction drink/FiO(2), P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise