1,752 research outputs found
Harvest and habitats of Atlantic sturgeon Acipenser oxyrinchus Mitchill, 1815 in the Hudson River estuary: Lessons for sturgeon conservation
Conservation of the Hudson River population of the sturgeon Acipenser oxyrinchus Mitchill, 1815 has benefitted from the most intensive research programme on any population of the species. We review the history of the fishery for A. oxyrinchus in the Hudson River, and concisely summarise diverse research findings on its life history and habitat use. The fishery for A. oxyrinchus from the Hudson River had one period of very high harvest (pre-1900s), a long period (1900-1979) of minimal harvest and slow population recovery, a period (1980-1992) of restored abundance and high harvest, and finally another decline and suspension of fishing (1996). Sturgeon spawning and early juvenile development occurs in the freshwater portion of the Hudson River, whereas adult and large juvenile sturgeon occupy marine waters, and some of these fish will annually occupy low salinity sites in the Hudson River and other coastal rivers in summer. A. oxyrinchus of the Hudson River are genetically distinct from other populations associated with rivers along the Atlantic coast. Eight different habitats are used during the life cycle of Hudson River A. oxyrinchus, and these are described in physical and temporal terms. The history and biology of the Hudson River A. oxyrinchus suggest three lessons for sturgeon restoration: basic life history knowledge is essential, fishery management is difficult, and regular population monitoring will be needed from the start.La conservación de la población del río Hudson de esturión Acipenser oxyrinchus Mitchill, 1815 se ha beneficiado del programa de investigación más intensivo de los proyectados en la preservación de cualquier otra población de la especie. Se revisa aquí la historia de la pesca de A. oxyrinchus en el río Hudson y se resumen concisamente diversos hallazgos de investigación sobre su historia natural y uso del hábitat. La pesca de A. oxyrinchus en el río Hudson tuvo un periodo de muy alta explotación (antes de 1900), un largo periodo de mínima explotación y lenta recuperación poblacional (1900-1979), un periodo de restauración de abundancia y alta explotación (1980-1992) y, finalmente, otro declive y suspensión de la pesca (1996). La puesta del esturión y el desarrollo temprano de los juveniles tienen lugar en el tramo de agua dulce del río Hudson, mientras los adultos y los juveniles grandes ocupan aguas marinas; algunos de estos peces ocuparán anualmente, en verano, lugares de baja salinidad en el Hudson y en otros ríos costeros. La población de A. oxyrinchus del río Hudson es distinta genéticamente de otras poblaciones asociadas con ríos a lo largo de la costa atlántica. Durante su ciclo vital, el A. oxyrinchus del río Hudson utiliza ocho diferentes hábitats, que son descritos en términos físicos y temporales. La historia y la biología de esta especie del río Hudson sugieren tres lecciones para la restauración de los esturiones: es imprescindible el conocimiento básico de la historia natural, la gestión de la pesca es difícil y el seguimiento regular de la población será necesario desde el principio.Instituto Español de Oceanografí
Hypoxia-induced fatty acid transporter translocation increases fatty acid transport and contributes to lipid accumulation in the heart
AbstractProtein-mediated LCFA transport across plasma membranes is highly regulated by the fatty acid transporters FAT/CD36 and FABPpm. Physiologic stimuli (insulin stimulation, AMP kinase activation) induce the translocation of one or both transporters to the plasma membrane and increase the rate of LCFA transport. In the hypoxic/ischemic heart, intramyocardial lipid accumulation has been attributed to a reduced rate of fatty acid oxidation. However, since acute hypoxia (15min) activates AMPK, we examined whether an increased accumulation of intramyocardial lipid during hypoxia was also attributable to an increased rate of LCFA uptake as a result AMPK-induced translocation of FAT/CD36 and FABPpm. In cardiac myocytes, hypoxia (15min) induced the redistribution of FAT/CD36 from an intracellular pool (LDM) (−25%, P<0.05) to the plasma membranes (PM) (+54%, P<0.05). Hypoxia also induced an increase in FABPpm at the PM (+56%, P<0.05) and a concomitant FABPpm reduction in the LDM (−24%, P<0.05). Similarly, in intact, Langendorff perfused hearts, hypoxia induced the translocation of a both FAT/CD36 and FABPpm to the PM (+66% and +61%, respectively, P<0.05), with a concomitant decline in FAT/CD36 and FABPpm in the LDM (−24% and −23%, respectively, P<0.05). Importantly, the increased plasmalemmal content of these transporters was associated with increases in the initial rates of palmitate uptake into cardiac myocytes (+40%, P<0.05). Acute hypoxia also redirected palmitate into intracellular lipid pools, mainly to PL and TG (+48% and +28%, respectively, P<0.05), while fatty acid oxidation was reduced (−35%, P<0.05). Thus, our data indicate that the increased intracellular lipid accumulation in hypoxic hearts is attributable to both: (a) a reduced rate of fatty acid oxidation and (b) an increased rate of fatty acid transport into the heart, the latter being attributable to a hypoxia-induced translocation of fatty acid transporters
Interference of multi-mode photon echoes generated in spatially separated solid-state atomic ensembles
High-visibility interference of photon echoes generated in spatially
separated solid-state atomic ensembles is demonstrated. The solid state
ensembles were LiNbO waveguides doped with Erbium ions absorbing at 1.53
m. Bright coherent states of light in several temporal modes (up to 3) are
stored and retrieved from the optical memories using two-pulse photon echoes.
The stored and retrieved optical pulses, when combined at a beam splitter, show
almost perfect interference, which demonstrates both phase preserving storage
and indistinguishability of photon echoes from separate optical memories. By
measuring interference fringes for different storage times, we also show
explicitly that the visibility is not limited by atomic decoherence. These
results are relevant for novel quantum repeaters architectures with photon echo
based multimode quantum memories
Excess wing in glass-forming glycerol and LiCl-glycerol mixtures detected by neutron scattering
The relaxational dynamics in glass-forming glycerol and glycerol mixed with
LiCl is in-vestigated using different neutron scattering techniques. The
performed neutron spin-echo experiments, which extend up to relatively long
relaxation-time scales of the order of 10 ns, should allow for the detection of
contributions from the so-called excess wing. This phenomenon, whose
microscopic origin is controversially discussed, arises in a variety of glass
formers and, until now, was almost exclusively investigated by dielectric
spectros-copy and light scattering. Here we show that the relaxational process
causing the excess wing also can be detected by neutron scattering, which
directly couples to density fluctua-tions.Comment: 8 pages, 6 figure
Intra-uterine exposure to selective serotonin reuptake inhibitors (SSRIs), maternal psychopathology, and neurodevelopment at age 2.5years-Results from the prospective cohort SMOK study
Background: Selective serotonin reuptake inhibitors (SSRIs) are prescribed in 2-8% during pregnancy. Whether prenatal exposure to SSRIs has long-term effects on the children's development is unknown. Aim: The aim of this study was to determine the effect of prenatal exposure to SSRIs on children's cognitive, motor, and behavioral outcomes at 2.5 years, adjusted for maternal depression and anxiety. Methods: In a prospective, longitudinal cohort-study we included 111 pregnant women treated either or not with an SSRI. We examined cognitive and motor development of their children at 2.5 years, using the Bayley Scale of Infant and Toddler Development, 3rd Edition, and measured emotional and behavioral problems using the parent-rated Child Behavior Checklist (CBCL). Maternal depression and anxiety was determined during pregnancy and at the children's assessment. Differences of normed cognitive, motor, and behavioral scores between SSRI-exposed and non-SSRI-exposed children were tested using multiple linear regression analyses. Results: We examined 102 children. SSRI-exposed children had lower scaled scores on cognition and gross motor development than non-SSRI-exposed children: 9.0 +/- 1.4 (mean +/- SD) versus 9.9 +/- 1.7 [P = 0.004], and 7.9 +/- 2.2 versus 9.0 +/- 2.5 [P = 0.01], respectively. Differences remained significant after adjusting for maternal depression and anxiety and other confounders in various models (mean difference for cognition 0.8 to 0.9 points, for gross motor 1.1 to 1.2 points). Only after adjusting for severity of maternal anxiety, differences in gross motor scores lost significance. Conclusions: Prenatal exposure to SSRIs is associated with poorer cognitive and gross motor development of the children at 2.5 years. Effects on gross motor development disappeared after correction for severity of maternal anxiety
The Predictive Value of Amplitude-Integrated Electroencephalography in Preterm Infants for IQ and Other Neuropsychological Outcomes at Early School Age
Background: Amplitude-integrated electroencephalography (aEEG) is used increasingly in neonatal intensive care and seems helpful in predicting outcomes at the age of 2 years, Objectives:To determine whether early aEEG patterns in preternn infants are equally useful in predicting outcomes at early school age. Methods: We recorded aEEG in 41 pre-terms (gestational age 26.0-32.9 weeks) at a median postnatal age of 9.7 h (IQR 7.0-25.3) and in 43 preternns on median day 8 (IQR 7-9). We assessed aEEG by pattern recognition and calculated the means of the aEEG amplitude centiles. At a median of 739 years, i.e., early school age, we assessed their motor, cognitive, and behavioral outcomes. Results: Depressed aEEG patterns were not associated with poorer outcomes. Cyclicity directly after birth was associated with a higher total IQ (mean 104 vs. 97, p = 0.05) and higher scores on visual perception (mean percentile 57.1 vs. 40.1, p 0,049) and visual memory (mean percentile 34.5 vs. 19.1, p = 0090). We found some associations between the aEEG amplitude centiles and cognitive outcomes, but none for motor or behavioral outcomes. There was an increased risk of abnormal scores on long-term verbal memory in cases of the lower 5th and 50th aEEG amplitude centiles directly after birth. The odds ratios were 0.65 (95% CI 0,42-0.99, p = 0.040) and 0.71 (95% CI 0.52-0.96, p = 0.025), respectively. Conclusions: In relatively healthy preternn infants the value of aEEG in predicting neuropsychological outcomes at early school age is limited. The presence of cyclicity directly after birth tends to be associated with better cognition. (C) 2018 The Author(s) Published by S. Karger AG, Base
Long-term (>10 years) prognostic value of dobutamine stress echocardiography in a high-risk cohort
The prognostic value of dobutamine stress echocardiography (DSE) at >10-year follow-up is unknown. The aim of this study was to assess the very long-term prognostic value of DSE in a high-risk cohort of patients with known or suspected coronary artery disease. This prospective, single-center study included 3,381 patients who underwent DSE from January 1990 to January 2003. Two-dimensional echocardiographic images were acquired at rest, during dobutamine stress, and during recovery. Follow-up events were collected and included overall mortality, cardiac death, nonfatal myocardial infarction, and revascularization. The incremental value of DSE in the prediction of selected end points was evaluated using multivariate Cox proportional hazard analysis. During a mean follow-up of 13 ± 3.2 years (range 7.3 to 20.5 years), there were 1,725 deaths (51%), of which 1,128 (33%) were attributed to cardiac causes. Patients with an abnormal DSE had a higher mortality rate (44% vs 35% at 15-year follow-up, p <0.001) than those with a normal DSE. When comparing echocardiographic variables at rest to variables at maximum dose dobutamine, the chi-square of the test improved from 842 to 870 (p <0.0001) and from 684 to 740 (p <0.0001) for all-cause mortality and cardiac death, respectively. DSE provided incremental value in predicting all-cause mortality, cardiac death, and hard cardiac events. There seems, however, to be a "warranty period" of approximately 7 years, when the survival curves of a normal and abnormal DSE no longer diverge
Visuospatial Perception in Children Born Preterm With No Major Neurological Disorders
Objective: Many investigations have found deficits in visuospatial perception in children born preterm, however, it is not clear whether the deficits are specific to visuospatial perception or the consequences of deficits in other functional areas, whic
The evolution of representation in simple cognitive networks
Representations are internal models of the environment that can provide
guidance to a behaving agent, even in the absence of sensory information. It is
not clear how representations are developed and whether or not they are
necessary or even essential for intelligent behavior. We argue here that the
ability to represent relevant features of the environment is the expected
consequence of an adaptive process, give a formal definition of representation
based on information theory, and quantify it with a measure R. To measure how R
changes over time, we evolve two types of networks---an artificial neural
network and a network of hidden Markov gates---to solve a categorization task
using a genetic algorithm. We find that the capacity to represent increases
during evolutionary adaptation, and that agents form representations of their
environment during their lifetime. This ability allows the agents to act on
sensorial inputs in the context of their acquired representations and enables
complex and context-dependent behavior. We examine which concepts (features of
the environment) our networks are representing, how the representations are
logically encoded in the networks, and how they form as an agent behaves to
solve a task. We conclude that R should be able to quantify the representations
within any cognitive system, and should be predictive of an agent's long-term
adaptive success.Comment: 36 pages, 10 figures, one Tabl
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