220 research outputs found

    Recognizing and Addressing Risk Ambiguity in Sea Level Rise Adaptation Planning: a Case Study of Miami-Dade County, Florida

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    As coastal cities around the world identify and implement adaptations to sea level rise, they are faced with competing interests around what should be done and how to prioritize actions. Often, environmental problems--like confronting the challenge of sea level rise--are posed as requiring expert driven, technical solutions to identify and mitigate risks across the landscape. This framing, however, ignores the way in which diverse knowledge can help inform long-term planning horizons that address complex ways that sea level rise affects communities. The failure to integrate diverse knowledge into sea level rise adaptation can result in barriers to implementation and outcomes that can reproduce inequities. In environmental planning, knowledge integration challenges can stem from ambiguity around the construction of environmental risk knowledge, as well as institutional arrangements that inhibit diverse involvement. Ambiguity refers to a context in which there are different and sometimes conflicting views on how to understand the problem or system to be managed, for example, conflicts around what risks to measure and how to measure them. This manifests in the ways that different groups construct and use knowledge about risks. Often ignored in planning contexts and research on sea level rise adaptation, ambiguity--particularly around social risks--are critical to address, since they can determine whether diverse knowledge about risks are integrated or ignored in planning. This dissertation uses a case study of Miami-Dade County, Florida and is guided by the question: how do different groups understand risk within sea level rise, and what planning and governance factors influence the way diverse dimensions of risk are integrated into adaptation strategies? Findings from this case study suggest that baselines, projections, and the focus of risk rooted in an economic discourse based on short-term planning horizons and technical constructions of risk have more authority as compared with counter arguments around ecological and social risks. Recommendations include the need for transparent adaptation decisions and the inclusion of diverse stakeholders in the production of regional climate science, sea level rise assessments, and adaptation planning. A more integrated approach can better address diverse risks and facilitate long-term planning

    Human Dimensions of Puget Sound Ecosystem Health and Recovery: Social Sciences Scale and Scope

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    The Puget Sound Basin is surrounded by human settlements that range from small resource-dependent communities, to metropolitan areas that are experiencing rapid population growth. Scientific studies in the biophysical disciplines have documented the Puget Sound\u27s ecological decline, established baseline conditions for recovery, and identified human-based sources of ecosystem impacts. The Puget Sound region is a complex socio-ecological system thus making equal attention to human dimensions an important goal, even a necessity. Social scientists across a variety of disciplines (such as economics, geography, anthropology, sociology, and psychology) can contribute to large-scale ecosystem health and recovery in two general ways. First, studies can serve to describe and highlight the human systems conditions that generate negative impacts on Puget Sound health. Second, and more importantly perhaps, the social sciences seek to understand how to better engage diverse human populations in greater awareness, deeper understanding, and committed behavior toward ecosystem recovery. We offer a comprehensive overview of human dimensions topics (that are generally aligned with various social science disciplines) that can serve to inform policy and action. This extensive literature review seeks to reconcile common perceptions that regard people as the source of ecological problems with knowledge that can support strategies to engage people in solutions. We present a framework of the human dimension of ecosystem recovery, describing how human activity at different scales can affect change in social-ecological systems. Each of the eight topics in our framework (Table 1- attached) is highlighted using a combination of general principles, theory and prior research, incorporating examples from studies done in the Puget Sound region when possible. Better understanding of this rich potential can contribute to better integration with biophysical knowledge to achieve recovery of large, complex ecological systems. The comprehensive overview of human dimensions topics will foster and support dialog about the scientific basis of a socio-ecological systems approach for Puget Sound recovery

    Changes in fetal mannose and other carbohydrates induced by a maternal insulin infusion in pregnant sheep

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    BACKGROUND: The importance of non-glucose carbohydrates, especially mannose and inositol, for normal development is increasingly recognized. Whether pregnancies complicated by abnormal glucose transfer to the fetus also affect the regulation of non-glucose carbohydrates is unknown. In pregnant sheep, maternal insulin infusions were used to reduce glucose supply to the fetus for both short (2-wk) and long (8-wk) durations to test the hypothesis that a maternal insulin infusion would suppress fetal mannose and inositol concentrations. We also used direct fetal insulin infusions (1-wk hyperinsulinemic-isoglycemic clamp) to determine the relative importance of fetal glucose and insulin for regulating non-glucose carbohydrates. RESULTS: A maternal insulin infusion resulted in lower maternal (50%, P < 0.01) and fetal (35-45%, P < 0.01) mannose concentrations, which were highly correlated (r(2) = 0.69, P < 0.01). A fetal insulin infusion resulted in a 50% reduction of fetal mannose (P < 0.05). Neither maternal nor fetal plasma inositol changed with exogenous insulin infusions. Additionally, maternal insulin infusion resulted in lower fetal sorbitol and fructose (P < 0.01). CONCLUSIONS: Chronically decreased glucose supply to the fetus as well as fetal hyperinsulinemia both reduce fetal non-glucose carbohydrates. Given the role of these carbohydrates in protein glycosylation and lipid production, more research on their metabolism in pregnancies complicated by abnormal glucose metabolism is clearly warranted

    Intrauterine growth restriction increases fetal hepatic gluconeogenic capacity and reduces messenger ribonucleic acid translation initiation and nutrient sensing in fetal liver and skeletal muscle.

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    Expression of key metabolic genes and proteins involved in mRNA translation, energy sensing, and glucose metabolism in liver and skeletal muscle were investigated in a late-gestation fetal sheep model of placental insufficiency intrauterine growth restriction (PI-IUGR). PI-IUGR fetuses weighed 55% less; had reduced oxygen, glucose, isoleucine, insulin, and IGF-I levels; and had 40% reduction in net branched chain amino acid uptake. In PI-IUGR skeletal muscle, levels of insulin receptor were increased 80%, whereas phosphoinositide-3 kinase (p85) and protein kinase B (AKT2) were reduced by 40%. Expression of eukaryotic initiation factor-4e was reduced 45% in liver, suggesting a unique mechanism limiting translation initiation in PI-IUGR liver. There was either no change (AMP activated kinase, mammalian target of rapamycin) or a paradoxical decrease (protein phosphatase 2A, eukaryotic initiation factor-2 alpha) in activation of major energy and cell stress sensors in PI-IUGR liver and skeletal muscle. A 13- to 20-fold increase in phosphoenolpyruvate carboxykinase and glucose 6 phosphatase mRNA expression in the PI-IUGR liver was-associated with a 3-fold increase in peroxisome proliferator-activated receptor-gamma coactivator-1 alpha mRNA and increased phosphorylation of cAMP response element binding protein. Thus PI-IUGR is-associated with reduced branched chain amino acid uptake and growth factors, yet up-regulation of proximal insulin signaling and a marked increase in the gluconeogenic pathway. Lack of activation of several energy and stress sensors in fetal liver and skeletal muscle, despite hypoxia and low energy status, suggests a novel strategy for survival in the PI-IUGR fetus but with potential maladaptive consequences for reduced nutrient sensing and insulin sensitivity in postnatal life

    Chronic late-gestation hypoglycemia upregulates hepatic PEPCK associated with increased PGC1alpha mRNA and phosphorylated CREB in fetal sheep.

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    Hepatic glucose production is normally activated at birth but has been observed in response to experimental hypoglycemia in fetal sheep. The cellular basis for this process remains unknown. We determined the impact of 2 wk of fetal hypoglycemia during late gestation on enzymes responsible for hepatic gluconeogenesis, focusing on the insulin-signaling pathway, transcription factors, and coactivators that regulate gluconeogenesis. Hepatic phosphoenolpyruvate carboxykinase and glucose-6-phosphatase mRNA increased 12-fold and 7-fold, respectively, following chronic hypoglycemia with no change in hepatic glycogen. Chronic hypoglycemia decreased fetal plasma insulin with no change in glucagon but increased plasma cortisol 3.5-fold. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha mRNA and phosphorylation of cAMP response element binding protein at Ser(133) were both increased, with no change in Akt, forkhead transcription factor FoxO1, hepatocyte nuclear factor-4alpha, or CCAAT enhancer binding protein-beta. These results demonstrate that chronic fetal hypoglycemia triggers signals that can activate gluconeogenesis in the fetal liver

    Early blood glucose profile and neurodevelopmental outcome at two years in neonatal hypoxic-ischaemic encephalopathy

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    Background: To examine the blood glucose profile and the relationship between blood glucose levels and neurodevelopmental outcome in term infants with hypoxic-ischaemic encephalopathy. Methods: Blood glucose values within 72 hours of birth were collected from 52 term infants with hypoxic-ischaemic encephalopathy. Hypoglycaemia [ 150 mg/dL (8.3 mmol/L)] were correlated to neurodevelopmental outcome at 24 months of age. Results: Four fifths of the 468 blood samples were in the normoglycaemic range (392/468:83.8%). Of the remaining 76 samples, 51.3% were in the hypoglycaemic range and (48.7%) were hyperglycaemic. A quarter of the hypoglycaemic samples (28.2%:11/39) and a third of the hyperglycaemic samples (32.4%:12/37) were recorded within the first 30 minutes of life. Mean (SD) blood glucose values did not differ between infants with normal and abnormal outcomes [4.89(2.28) mmol/L and 5.02(2.35) mmol/L, p value = 0.15] respectively. In term infants with hypoxic-ischaemic encephalopathy, early hypoglycaemia (between 0-6 hours of life) was associated with adverse outcome at 24 months of age [OR = 5.8, CI = 1.04-32)]. On multivariate analysis to adjust for grade of HIE this association was not statistically significant. Late hypoglycaemia (6-72 hours of life) was not associated with abnormal outcome [OR = 0.22, CI (0.04-1.14)]. The occurrence of hyperglycaemia was not associated with adverse outcome. Conclusion: During the first 72 hours of life, blood glucose profile in infants with hypoxic-ischaemic encephalopathy varies widely despite a management protocol. Early hypoglycaemia (0-6 hours of life) was associated with severe HIE, and thereby; adverse outcome

    Hypoglycemia and the Origin of Hypoxia-Induced Reduction in Human Fetal Growth

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    The most well known reproductive consequence of residence at high altitude (HA >2700 m) is reduction in fetal growth. Reduced fetoplacental oxygenation is an underlying cause of pregnancy pathologies, including intrauterine growth restriction and preeclampsia, which are more common at HA. Therefore, altitude is a natural experimental model to study the etiology of pregnancy pathophysiologies. We have shown that the proximate cause of decreased fetal growth is not reduced oxygen availability, delivery, or consumption. We therefore asked whether glucose, the primary substrate for fetal growth, might be decreased and/or whether altered fetoplacental glucose metabolism might account for reduced fetal growth at HA.Doppler and ultrasound were used to measure maternal uterine and fetal umbilical blood flows in 69 and 58 residents of 400 vs 3600 m. Arterial and venous blood samples from mother and fetus were collected at elective cesarean delivery and analyzed for glucose, lactate and insulin. Maternal delivery and fetal uptakes for oxygen and glucose were calculated.The maternal arterial – venous glucose concentration difference was greater at HA. However, umbilical venous and arterial glucose concentrations were markedly decreased, resulting in lower glucose delivery at 3600 m. Fetal glucose consumption was reduced by >28%, but strongly correlated with glucose delivery, highlighting the relevance of glucose concentration to fetal uptake. At altitude, fetal lactate levels were increased, insulin concentrations decreased, and the expression of GLUT1 glucose transporter protein in the placental basal membrane was reduced.Our results support that preferential anaerobic consumption of glucose by the placenta at high altitude spares oxygen for fetal use, but limits glucose availability for fetal growth. Thus reduced fetal growth at high altitude is associated with fetal hypoglycemia, hypoinsulinemia and a trend towards lactacidemia. Our data support that placentally-mediated reduction in glucose transport is an initiating factor for reduced fetal growth under conditions of chronic hypoxemia

    Towards reducing variations in infant mortality and morbidity : a population-based approach

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    Background: Our aims were (1) to improve understanding of regional variation in early-life mortality rates and the UK’s poor performance in international comparisons; and (2) to identify the extent to which late and moderately preterm (LMPT) birth contributes to early childhood mortality and morbidity. Objective: To undertake a programme of linked population-based research studies to work towards reducing variations in infant mortality and morbidity rates. Design: Two interlinked streams: (1) a detailed analysis of national and regional data sets and (2) establishment of cohorts of LMPT babies and term-born control babies. Setting: Cohorts were drawn from the geographically defined areas of Leicestershire and Nottinghamshire, and analyses were carried out at the University of Leicester. Data sources: For stream 1, national data were obtained from four sources: the Office for National Statistics, NHS Numbers for Babies, Centre for Maternal and Child Enquiries and East Midlands and South Yorkshire Congenital Anomalies Register. For stream 2, prospective data were collected for 1130 LMPT babies and 1255 term-born control babies. Main outcome measures: Detailed analysis of stillbirth and early childhood mortality rates with a particular focus on factors leading to biased or unfair comparison; review of clinical, health economic and developmental outcomes over the first 2 years of life for LMPT and term-born babies. Results: The deprivation gap in neonatal mortality has widened over time, despite government efforts to reduce it. Stillbirth rates are twice as high in the most deprived as in the least deprived decile. Approximately 70% of all infant deaths are the result of either preterm birth or a major congenital abnormality, and these are heavily influenced by mothers’ exposure to deprivation. Births at < 24 weeks’ gestation constitute only 1% of all births, but account for 20% of infant mortality. Classification of birth status for these babies varies widely across England. Risk of LMPT birth is greatest in the most deprived groups within society. Compared with term-born peers, LMPT babies are at an increased risk of neonatal morbidity, neonatal unit admission and poorer long-term health and developmental outcomes. Cognitive and socioemotional development problems confer the greatest long-term burden, with the risk being amplified by socioeconomic factors. During the first 24 months of life each child born LMPT generates approximately £3500 of additional health and societal costs. Conclusions: Health professionals should be cautious in reviewing unadjusted early-life mortality rates, particularly when these relate to individual trusts. When more sophisticated analysis is not possible, babies of < 24 weeks’ gestation should be excluded. Neonatal services should review the care they offer to babies born LMPT to ensure that it is appropriate to their needs. The risk of adverse outcome is low in LMPT children. However, the risk appears higher for some types of antenatal problems and when the mother is from a deprived background
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