766 research outputs found

    Helping children understand divorce (2004)

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    "This guide is a revision and update of two previous guides: Helping Children Understand Divorce, originally written by Sara Gable, state specialist in human development and family studies at the University of Missouri-Columbia, and Kelly Cole, former extension associate at the University of Missouri-Columbia, and The Effects of Divorce on Children, originally written by Karen DeBord, former state specialist in human development and family studies at the University of Missouri-Columbia.""Information from Human Environmental Sciences Extension.""Family relations."Revised 3/04/10M

    Putting Quality Functional Assessment into Practice in Schools: A Research Agenda on Behalf of E/BD Students

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    The discipline provisions of the IDEA place emphasis on gaining an understanding of why the student is motivated to engage in problem behavior and to consider, when appropriate, positive behavioral interventions, strategies, and supports to address the behavior. These legislative mandates bring center stage a range of new duties and responsibilities for the IEP team. This article discusses the problems that school divisions across the country are encountering when implementing these requirements and recommends a course of research to address these issues

    Mechanism of sphingolipid homeostasis revealed by structural analysis of \u3ci\u3eArabidopsis\u3c/i\u3e SPT-ORM1 complex

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    The serine palmitoyltransferase (SPT) complex catalyzes the first and rate-limiting step in sphingolipid biosynthesis in all eukaryotes. ORM/ORMDL proteins are negative regulators of SPT that respond to cellular sphingolipid levels. However, the molecular basis underlying ORM/ORMDL-dependent homeostatic regulation of SPT is not well understood.We determined the cryo–electron microscopy structure of Arabidopsis SPT-ORM1 complex, composed of LCB1, LCB2a, SPTssa, and ORM1, in an inhibited state. A ceramide molecule is sandwiched between ORM1 and LCB2a in the cytosolic membrane leaflet. Ceramide binding is critical for the ORM1-dependent SPT repression, and dihydroceramides and phytoceramides differentially affect this repression. A hybrid ÎČ sheet, formed by the amino termini of ORM1 and LCB2a and induced by ceramide binding, stabilizes the amino terminus of ORM1 in an inhibitory conformation. Our findings provide mechanistic insights into sphingolipid homeostatic regulation via the binding of ceramide to the SPT-ORM/ORMDL complex that may have implications for plant-specific processes such as the hypersensitive response for microbial pathogen resistance

    Sphingolipids in the Root Play an Important Role in Regulating the Leaf Ionome in \u3ci\u3eArabidopsis thaliana\u3c/i\u3e

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    Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10D mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis

    Recurrent de novo SPTLC2 variant causes childhood-onset amyotrophic lateral sclerosis (ALS) by excess sphingolipid synthesis

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    BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the upper and lower motor neurons with varying ages of onset, progression and pathomechanisms. Monogenic childhood-onset ALS, although rare, forms an important subgroup of ALS. We recently reported specific SPTLC1 variants resulting in sphingolipid overproduction as a cause for juvenile ALS. Here, we report six patients from six independent families with a recurrent, de novo, heterozygous variant in SPTLC2 c.778G>A [p.Glu260Lys] manifesting with juvenile ALS. METHODS: Clinical examination of the patients along with ancillary and genetic testing, followed by biochemical investigation of patients' blood and fibroblasts, was performed. RESULTS: All patients presented with early-childhood-onset progressive weakness, with signs and symptoms of upper and lower motor neuron degeneration in multiple myotomes, without sensory neuropathy. These findings were supported on ancillary testing including nerve conduction studies and electromyography, muscle biopsies and muscle ultrasound studies. Biochemical investigations in plasma and fibroblasts showed elevated levels of ceramides and unrestrained de novo sphingolipid synthesis. Our studies indicate that SPTLC2 variant [c.778G>A, p.Glu260Lys] acts distinctly from hereditary sensory and autonomic neuropathy (HSAN)-causing SPTLC2 variants by causing excess canonical sphingolipid biosynthesis, similar to the recently reported SPTLC1 ALS associated pathogenic variants. Our studies also indicate that serine supplementation, which is a therapeutic in SPTLC1 and SPTCL2-associated HSAN, is expected to exacerbate the excess sphingolipid synthesis in serine palmitoyltransferase (SPT)-associated ALS. CONCLUSIONS: SPTLC2 is the second SPT-associated gene that underlies monogenic, juvenile ALS and further establishes alterations of sphingolipid metabolism in motor neuron disease pathogenesis. Our findings also have important therapeutic implications: serine supplementation must be avoided in SPT-associated ALS, as it is expected to drive pathogenesis further

    Costa Rica Rift hole deepened and logged

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    During Leg 111 of the Ocean Drilling Program, scientists on the drilling vessel JOIDES Resolution studied crustal structure and hydrothermal processes in the eastern equatorial Pacific. Leg 111 spent 43 days on its primary objective, deepening and logging Hole 5048, a deep reference hole in 5.9-million-year-old crust 200 km south of the spreading axis of the Costa Rica Rift. Even before Leg 111 , Hole 5048 was the deepest hole drilled into the oceanic crust, penetrating 274.5 m of sediments and 1,075.5 m of pillow lavas and sheeted dikes to a total depth of 1,350 m below sea floor (mbsf). Leg 111 deepened the hole by 212.3 m to a total depth of 1,562.3 mbsf (1,287.8 m into basement), and completed a highly successful suite of geophysical logs and experiments, including sampling of borehole waters

    Semaglutide improves postprandial glucose and lipid metabolism, and delays first‐hour gastric emptying in subjects with obesity

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    Aim: To investigate the effects of semaglutide on fasting and postprandial glucose and lipid responses, and on gastric emptying. Materials and Methods: This was a randomised, double-blind, placebo-controlled, two-period, crossover trial. Subjects with obesity (N = 30) received once-weekly subcutaneous semaglutide, dose-escalated to 1.0 mg, or placebo. After each 12-week treatment period, glucose and lipid metabolism were assessed before and after standardised meals. Gastric emptying (paracetamol absorption test) and peptide YY (PYY) response were also assessed. Results: Semaglutide treatment significantly lowered fasting concentrations of glucose and glucagon, and increased insulin versus placebo (estimated treatment ratio: 0.95 [95% confidence interval: 0.91, 0.98]; 0.86 [0.75, 0.98]; 1.45 [1.20, 1.75], respectively). Postprandial glucose metabolism significantly improved with semaglutide versus placebo (incremental area under the curve 0–5 hours [iAUC0-5h]; estimated treatment difference: glucose −1.34 mmol*h/L [−2.42, −0.27]; insulin −921 pmol*h/L [−1461, −381]; C-peptide −1.42 nmol*h/L [−2.33, −0.51]). Fasting and postprandial lipid metabolism improved with semaglutide versus placebo. First-hour gastric emptying after the meal was delayed versus placebo (AUC0-1h; estimated treatment ratio: 0.73 [0.61, 0.87]); this may have contributed to the lower postprandial glucose increase in semaglutide-treated subjects. Overall gastric emptying (AUC0-5h) was not statistically different between treatments. Fasting and postprandial PYY responses were significantly lower with semaglutide versus placebo (p=0.0397 and p=0.0097, respectively). Conclusion: Semaglutide improved fasting and postprandial glucose and lipid metabolism. Overall gastric emptying was similar to placebo; however, the observed first-hour delay with semaglutide may contribute to a slower entry of glucose into the circulation
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