106 research outputs found
Unhappy Cities
There are persistent differences in self-reported subjective well-being across US metropolitan areas, and residents of declining cities appear less happy than others. Yet some people continue to move to these areas, and newer residents appear to be as unhappy as longer-term residents. While historical data on happiness are limited, the available facts suggest that cities that are now declining were also unhappy in their more prosperous past. These facts support the view that individuals do not maximize happiness alone but include it in the utility function along with other arguments. People may trade off happiness against other competing objectives
Preterm infant meconium microbiota transplant induces growth failure, inflammatory activation, and metabolic disturbances in germ-free mice
Preterm birth may result in adverse health outcomes. Very preterm infants typically exhibit postnatal growth restriction, metabolic disturbances, and exaggerated inflammatory responses. We investigated the differences in the meconium microbiota composition between very preterm (37 weeks) human neonates by 16S rRNA gene sequencing. Human meconium microbiota transplants to germ-free mice were conducted to investigate whether the meconium microbiota is causally related to the preterm infant phenotype in an experimental model. Our results indicate that very preterm birth is associated with a distinct meconium microbiota composition. Fecal microbiota transplant of very preterm infant meconium results in impaired growth, altered intestinal immune function, and metabolic parameters as compared to term infant meconium transplants in germ-free mice. This finding suggests that measures aiming to minimize the long-term adverse consequences of very preterm birth should be commenced during pregnancy or directly after birth.</p
Genetic markers of Restless Legs Syndrome in Parkinson disease
INTRODUCTION:
Several studies proposed that Restless Legs Syndrome (RLS) and Parkinson disease (PD) may be clinically and/or etiologically related. To examine this hypothesis, we aimed to determine whether the known RLS genetic markers may be associated with PD risk, as well as with PD subtype.
METHODS:
Two case-control cohorts from Tel-Aviv and New-York, including 1133 PD patients and 867 controls were genotyped for four RLS-related SNPs in the genes MEIS1, BTBD9, PTPRD and MAP2K5/SKOR1. The association between genotype, PD risk and phenotype was tested using multivariate regression models.
RESULTS:
None of the tested SNPs was significantly associated with PD risk, neither in any individual cohort nor in the combined analysis after correction for multiple comparisons. The MAP2K5/SKOR1 marker rs12593813 was associated with higher frequency of tremor in the Tel-Aviv cohort (61.0% vs. 46.5%, p = 0.001, dominant model). However, the risk allele for tremor in this gene has been associated with reduced RLS risk. Moreover, this association did not replicate in Tremor-dominant PD patients from New-York.
CONCLUSION:
RLS genetic risk markers are not associated with increased PD risk or subtype in the current study. Together with previous genetic, neuropathological and epidemiologic studies, our results further strengthen the notion that RLS and PD are likely to be distinct entities
Analysis of common and rare VPS13C variants in late-onset Parkinson disease
Objective
We aimed to study the role of coding VPS13C variants in a large cohort of patients with lateonset Parkinson disease (PD) (LOPD).
Methods
VPS13C and its untranslated regions were sequenced using targeted next-generation sequencing in 1,567 patients with PD and 1,667 controls from 3 cohorts. Association tests of rare
potential homozygous and compound heterozygous variants and burden tests for rare heterozygous variants were performed. Common variants were analyzed using logistic regression
adjusted for age and sex in each of the cohorts, followed by a meta-analysis.
Results
No biallelic carriers of rare VPS13C variants were found among patients, and 2 carriers of
compound heterozygous variants were found in 2 controls. There was no statistically significant
burden of rare (minor allele frequency [MAF] <1%) or very rare (MAF <0.1%) coding VPS13C
variants in PD. A VPS13C haplotype including the p.R153H-p.I398I-p.I1132V-p.Q2376Q
variants was nominally associated with a reduced risk for PD (meta-analysis of the tagging SNP
p.I1132V [odds ratio = 0.48, 95% confidence interval = 0.28–0.82, p = 0.0052]). This haplotype
was not in linkage disequilibrium with the known genome-wide association study top hit.
Conclusions
Our results do not support a role for rare heterozygous or biallelic VPS13C variants in LOPD.
Additional genetic replication and functional studies are needed to examine the role of the
haplotype identified here associated with reduced risk for PD
Cascading Failures in Production Networks *
Abstract I show how the extensive margin of firm entry and exit can greatly amplify idiosyncratic shocks in an economy with a production network. I show that input-output models with entry and exit behave very differently to models without this margin. In particular, in such models, sales provide a very poor measure of the systemic importance of firms or industries. I derive a new notion of systemic influence called exit centrality that captures how exits in one industry will affect equilibrium output. I show that exit centrality need not be monotonically related to an industry's sales, size, or prices. Unlike the relevant notions of centrality in standard input-output models, exit centrality depends on the industry's role as both a supplier and as a consumer of inputs. Furthermore, I show that granularities in systemically important industries can cause one failure to snowball into a large-scale avalanche of failures. In this sense, shocks can be amplified as they travel through the network, whereas in standard input-output models they cannot
Cascading Failures in Production Networks *
Abstract I show how the extensive margin of firm entry and exit can greatly amplify idiosyncratic shocks in an economy with a production network. I show that canonical input-output models, which lack the extensive margin of firm entry and exit, have some crucial limitations. In these models, the systemic importance of a firm does not respond to productivity shocks, depends only on the firm's role as a supplier, and is equal to or well-approximated by the firm's size. This means that for every canonical input-output model, there exists a non-interconnected model that has the same aggregate response to productivity shocks. I show that when we allow for entry and exit, the systemic importance of a firm responds endogenously to productivity shocks, depends on a firm's role not just as a supplier but also as a consumer, and a firm's systemic influence is no longer well-approximated by its size. Furthermore, I show that nondivisibilities in systemically important industries can cause one failure to snowball into a large-scale avalanche of failures. In this sense, shocks can be amplified as they travel through the network, whereas in canonical input-output models they cannot
Neonatal antibiotic exposure impairs child growth during the first six years of life by perturbing intestinal microbial colonization
Exposure to antibiotics in the first days of life is thought to affect various physiological aspects of neonatal development. Here, we investigate the long-term impact of antibiotic treatment in the neonatal period and early childhood on child growth in an unselected birth cohort of 12,422 children born at full term. We find significant attenuation of weight and height gain during the first 6 years of life after neonatal antibiotic exposure in boys, but not in girls, after adjusting for potential confounders. In contrast, antibiotic use after the neonatal period but during the first 6 years of life is associated with significantly higher body mass index throughout the study period in both boys and girls. Neonatal antibiotic exposure is associated with significant differences in the gut microbiome, particularly in decreased abundance and diversity of fecal Bifidobacteria until 2 years of age. Finally, we demonstrate that fecal microbiota transplant from antibiotic-exposed children to germ-free male, but not female, mice results in significant growth impairment. Thus, we conclude that neonatal antibiotic exposure is associated with a long-term gut microbiome perturbation and may result in reduced growth in boys during the first six years of life while antibiotic use later in childhood is associated with increased body mass index. In this study, Omry Koren, Samuli Rautava and colleagues report a sex-specific association between neonatal antibiotic exposure and weight and height gain during the first six years of life and showing that boys but not girls exposed to neonatal antibiotics exhibit impaired weight and height development
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