177 research outputs found
Recessions and Local Labor Market Hysteresis
This paper studies the effects of each U.S. recession since 1973 on local labor markets. We find that recession-induced declines in employment are permanent, suggesting that local areas experience permanent declines in labor demand relative to less-affected areas. Population also falls, primarily due to reduced in-migration, but by less than employment. As a result, recessions generate long-lasting hysteresis: persistent decreases in the employment-to-population ratio and earnings per capita. Changes in the composition of workers explain less than half of local hysteresis. We further show that finite sample bias in vector autoregressions leads to artificial convergence, which can explain why some previous work finds no evidence of hysteresis in employment rates
Place-Based Consequences of Person-Based Transfers: Evidence from Recessions
This paper studies how government transfers respond to changes in local economic activity that emerge during recessions. Local labor markets that experience greater employment losses during recessions face persistent relative decreases in earnings per capita. However, these areas also experience persistent increases in transfers per capita, which offset 16 percent of the earnings loss on average. The increase in transfers is driven by unemployment insurance in the short run, and medical, retirement, and disability transfers in the long run. Our results show that nominally place-neutral transfer programs redistribute considerable sums of money to places with depressed economic conditions
Maternal nutrient restriction in Guinea pigs leads to fetal growth restriction with evidence for chronic hypoxia
BackgroundWe determined whether maternal nutrient restriction (MNR) in Guinea pigs leading to fetal growth restriction (FGR) impacts markers for tissue hypoxia, implicating a mechanistic role for chronic hypoxia.MethodsGuinea pigs were fed ad libitum (Control) or 70% of the control diet before pregnancy, switching to 90% at mid-pregnancy (MNR). Near term, hypoxyprobe-1 (HP-1), a marker of tissue hypoxia, was injected into pregnant sows. Fetuses were then necropsied and liver, kidney, and placental tissues were processed for erythropoietin (EPO), EPO-receptor (EPOR), and vascular endothelial growth factor (VEGF) protein levels, and for HP-1 immunoreactivity (IR).ResultsFGR-MNR fetuses were 36% smaller with asymmetrical growth restriction compared to controls. EPO and VEGF protein levels were increased in the female FGR-MNR fetuses, providing support for hypoxic stimulus and linkage to increased erythropoiesis, but not in the male FGR-MNR fetuses, possibly reflecting a weaker link between oxygenation and erythropoiesis. HP-1 IR was increased in the liver and kidneys of both male and female FGR-MNR fetuses as an index of local tissue hypoxia, but with no changes in the placenta.ConclusionChronic hypoxia is likely to be an important signaling mechanism for the decreased fetal growth seen with maternal undernutrition and appears to be post-placental in nature
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Propranolol treatment of infantile hemangioma endothelial cells: A molecular analysis
Infantile hemangiomas (IHs) are non-malignant, largely cutaneous vascular tumors affecting approximately 5–10% of children to varying degrees. During the first year of life, these tumors are strongly proliferative, reaching an average size ranging from 2 to 20 cm. These lesions subsequently stabilize, undergo a spontaneous slow involution and are fully regressed by 5 to 10 years of age. Systemic treatment of infants with the non-selective β-adrenergic receptor blocker, propranolol, has demonstrated remarkable efficacy in reducing the size and appearance of IHs. However, the mechanism by which this occurs is largely unknown. In this study, we sought to understand the molecular mechanisms underlying the effectiveness of β blocker treatment in IHs. Our data reveal that propranolol treatment of IH endothelial cells, as well as a panel of normal primary endothelial cells, blocks endothelial cell proliferation, migration, and formation of the actin cytoskeleton coincident with alterations in vascular endothelial growth factor receptor-2 (VEGFR-2), p38 and cofilin signaling. Moreover, propranolol induces major alterations in the protein levels of key cyclins and cyclin-dependent kinase inhibitors, and modulates global gene expression patterns with a particular affect on genes involved in lipid/sterol metabolism, cell cycle regulation, angiogenesis and ubiquitination. Interestingly, the effects of propranolol were endothelial cell-type independent, affecting the properties of IH endothelial cells at similar levels to that observed in neonatal dermal microvascular and coronary artery endothelial cells. This data suggests that while propranolol markedly inhibits hemangioma and normal endothelial cell function, its lack of endothelial cell specificity hints that the efficacy of this drug in the treatment of IHs may be more complex than simply blockage of endothelial function as previously believed
The lifelong impact of fetal growth restriction on cardiac development
Background: Maternal nutrient restriction (MNR) is a widespread cause of fetal growth restriction (FGR), an independent predictor of heart disease and cardiovascular mortality. Our objective was to examine the developmental and long-term impact of MNR-induced FGR on cardiac structure in a model that closely mimics human development. Methods: A reduction in total caloric intake spanning pregestation through to lactation in guinea pig sows was used to induce FGR. Proliferation, differentiation, and apoptosis of cardiomyocytes were assessed in late-gestation fetal, neonatal, and adult guinea pig hearts. Proteomic analysis and pathway enrichment were performed on fetal hearts. Results: Cardiomyocyte proliferation and the number of mononucleated cells were enhanced in the MNR–FGR fetal and neonatal heart, suggesting a delay in cardiomyocyte differentiation. In fetal hearts of MNR–FGR animals, apoptosis was markedly elevated and the total number of cardiomyocytes reduced, the latter remaining so throughout neonatal and into adult life. A reduction in total cardiomyocyte number in adult MNR–FGR hearts was accompanied by exaggerated hypertrophy and a disorganized architecture. Pathway analysis identified genes related to cell proliferation, differentiation, and survival. Conclusions: FGR influences cardiomyocyte development during critical windows of development, leading to a permanent deficiency in cardiomyocyte number and compensatory hypertrophy in a rodent model that recapitulates human development
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