Recent Changes in the Law Affecting Educational Hearing Procedures for Handicapped Children

This article is a revised version of a report originally prepared for the Maryland State Bar Association, Special Committee on Law and the Handicapped by members of the Education Sub-committee. The article reviews and analyzes recent changes in the law affecting procedures for diagnosis, evaluation, and educational placement of handicapped children. The article reflects the views of the authors, and does not necessarily reflect the position of the Maryland State Bar Association

Algebraic approach in the study of time-dependent nonlinear integrable systems: Case of the singular oscillator

The classical and the quantal problem of a particle interacting in one-dimension with an external time-dependent quadratic potential and a constant inverse square potential is studied from the Lie-algebraic point of view. The integrability of this system is established by evaluating the exact invariant closely related to the Lewis and Riesenfeld invariant for the time-dependent harmonic oscillator. We study extensively the special and interesting case of a kicked quadratic potential from which we derive a new integrable, nonlinear, area preserving, two-dimensional map which may, for instance, be used in numerical algorithms that integrate the Calogero-Sutherland-Moser Hamiltonian. The dynamics, both classical and quantal, is studied via the time-evolution operator which we evaluate using a recent method of integrating the quantum Liouville-Bloch equations \cite{rau}. The results show the exact one-to-one correspondence between the classical and the quantal dynamics. Our analysis also sheds light on the connection between properties of the SU(1,1) algebra and that of simple dynamical systems.Comment: 17 pages, 4 figures, Accepted in PR

Output from VIP cells of the mammalian central clock regulates daily physiological rhythms

The suprachiasmatic nucleus (SCN) circadian clock is critical for optimising daily cycles in mammalian physiology and behaviour. The roles of the various SCN cell types in communicating timing information to downstream physiological systems remain incompletely understood, however. In particular, while vasoactive intestinal polypeptide (VIP) signalling is essential for SCN function and whole animal circadian rhythmicity, the specific contributions of VIP cell output to physiological control remains uncertain. Here we reveal a key role for SCN VIP cells in central clock output. Using multielectrode recording and optogenetic manipulations, we show that VIP neurons provide coordinated daily waves of GABAergic input to target cells across the paraventricular hypothalamus and ventral thalamus, supressing their activity during the mid to late day. Using chemogenetic manipulation, we further demonstrate specific roles for this circuitry in the daily control of heart rate and corticosterone secretion, collectively establishing SCN VIP cells as influential regulators of physiological timing

The Conservation Status of Marine Bony Shorefishes of the Greater Caribbean

The greater Caribbean biogeographic region covered in this report (representing 38 countries and territories) encompasses an outstanding marine bony shorefish richness of approximately 1,360 species, with many (53%) being endemic. This report provides an overview of the conservation status of greater Caribbean shorefishes, with detailed information available through the IUCN Red List, and gives recommendations

High Amplitude Phase Resetting in Rev-Erbα/Per1 Double Mutant Mice

Over time, organisms developed various strategies to adapt to their environment. Circadian clocks are thought to have evolved to adjust to the predictable rhythms of the light-dark cycle caused by the rotation of the Earth around its own axis. The rhythms these clocks generate persist even in the absence of environmental cues with a period of about 24 hours. To tick in time, they continuously synchronize themselves to the prevailing photoperiod by appropriate phase shifts. In this study, we disrupted two molecular components of the mammalian circadian oscillator, Rev-Erbα and Period1 (Per1). We found that mice lacking these genes displayed robust circadian rhythms with significantly shorter periods under constant darkness conditions. Strikingly, they showed high amplitude resetting in response to a brief light pulse at the end of their subjective night phase, which is rare in mammals. Surprisingly, Cry1, a clock component not inducible by light in mammals, became slightly inducible in these mice. Taken together, Rev-Erbα and Per1 may be part of a mechanism preventing drastic phase shifts in mammals

Experimental ‘Jet Lag’ Inhibits Adult Neurogenesis and Produces Long-Term Cognitive Deficits in Female Hamsters

Background: Circadian disruptions through frequent transmeridian travel, rotating shift work, and poor sleep hygiene are associated with an array of physical and mental health maladies, including marked deficits in human cognitive function. Despite anecdotal and correlational reports suggesting a negative impact of circadian disruptions on brain function, this possibility has not been experimentally examined. Methodology/Principal Findings: In the present study, we investigated whether experimental ‘jet lag ’ (i.e., phase advances of the light:dark cycle) negatively impacts learning and memory and whether any deficits observed are associated with reductions in hippocampal cell proliferation and neurogenesis. Because insults to circadian timing alter circulating glucocorticoid and sex steroid concentrations, both of which influence neurogenesis and learning/memory, we assessed the contribution of these endocrine factors to any observed alterations. Circadian disruption resulted in pronounced deficits in learning and memory paralleled by marked reductions in hippocampal cell proliferation and neurogenesis. Significantly, deficits in hippocampal-dependent learning and memory were not only seen during the period of the circadian disruption, but also persisted well after the cessation of jet lag, suggesting long-lasting negative consequences on brain function. Conclusions/Significance: Together, these findings support the view that circadian disruptions suppress hippocampal neurogenesis via a glucocorticoid-independent mechanism, imposing pronounced and persistent impairments on learnin

Orthopaedic management of Hurler’s disease after hematopoietic stem cell transplantation: a systematic review

The introduction of hematopoietic stem cell transplantation (HSCT) has significantly improved the life-span of Hurler patients (mucopolysaccharidosis type I-H, MPS I-H). Yet, the musculoskeletal manifestations seem largely unresponsive to HSCT. In order to facilitate evidence based management, the aim of the current study was to give a systematic overview of the orthopaedic complications and motor functioning of Hurler's patients after HSCT. A systematic review was conducted of the medical literature published from January 1981 to June 2010. Two reviewers independently assessed all eligible citations, as identified from the Pubmed and Embase databases. A pre-developed data extraction form was used to systematically collect information on the prevalence of radiological and clinical signs, and on the orthopaedic treatments and outcomes. A total of 32 studies, including 399 patient reports were identified. The most frequent musculoskeletal abnormalities were odontoid hypoplasia (72%), thoracolumbar kyphosis (81%), genu valgum (70%), hip dysplasia (90%) and carpal tunnel syndrome (63%), which were often treated surgically during the first decade of life. The overall complication rate of surgical interventions was 13.5%. Motor functioning was further hampered due to reduced joint mobility, hand dexterity, motor development and longitudinal growth. Stem cell transplantation does not halt the progression of a large range of disabling musculoskeletal abnormalities in Hurler's disease. Although prospective data on the quantification, progression and treatment of these deformities were very limited, early surgical intervention is often advocated. Prospective data collection will be mandatory to achieve better evidence on the effect of treatment strategies

Differential Expression of Cytokines in Response to Respiratory Syncytial Virus Infection of Calves with High or Low Circulating 25-Hydroxyvitamin D3

Deficiency of serum levels of 25-hydroxyvitamin D3 has been related to increased risk of lower respiratory tract infections in children. Respiratory syncytial virus (RSV) is a leading cause of low respiratory tract infections in infants and young children. The neonatal calf model of RSV infection shares many features in common with RSV infection in infants and children. In the present study, we hypothesized that calves with low circulating levels of 25-hydroxyvitamin D3 (25(OH)D3) would be more susceptible to RSV infection than calves with high circulating levels of 25(OH)D3. Calves were fed milk replacer diets with different levels of vitamin D for a 10 wk period to establish two treatment groups, one with high (177 ng/ml) and one with low (32.5 ng/ml) circulating 25(OH)D3. Animals were experimentally infected via aerosol challenge with RSV. Data on circulating 25(OH)D3 levels showed that high and low concentrations of 25(OH)D3 were maintained during infection. At necropsy, lung lesions due to RSV were similar in the two vitamin D treatment groups. We show for the first time that RSV infection activates the vitamin D intracrine pathway in the inflamed lung. Importantly, however, we observed that cytokines frequently inhibited by this pathway in vitro are, in fact, either significantly upregulated (IL-12p40) or unaffected (IFN-γ) in the lungs of RSV-infected calves with high circulating levels of 25(OH)D3. Our data indicate that while vitamin D does have an immunomodulatory role during RSV infection, there was no significant impact on pathogenesis during the early phases of RSV infection. Further examination of the potential effects of vitamin D status on RSV disease resolution will require longer-term studies with immunologically sufficient and deficient vitamin D levels