722 research outputs found

    Defensive Investments and the Demand for Air Quality: Evidence from the NOx Budget Program and Ozone Reductions

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    Willingness to pay for air quality is a function of health and the costly defensive investments that contribute to health, but there is little research assessing the empirical importance of defensive investments. The setting for this paper is a large US emissions cap and trade market – the NOx Budget Trading Program (NBP) – that has greatly reduced NOx emissions since its initiation in 2003. Using rich quasi-experimental variation, we find that the reductions in NOx emissions decreased the number of summer days with high ozone levels by about 25%. The NBP also led to reductions in expenditures on prescription pharmaceutical expenditures of about 1.9%. Additionally, the summer mortality rate declined by approximately 0.5%, indicating that there were about 2,200 fewer premature deaths per summer, mainly among individuals 75 and older. The monetized value of the reductions in pharmaceutical purchases and mortality rates are each roughly $900 million annually, suggesting that defensive investments are a significant portion of willingness to pay for air quality. Finally, we cautiously conclude that the reductions in ozone are the primary channel for these reductions in defensive investments and mortality rates, which indicates that willingness to pay for ozone reductions is larger than previously understood

    Direct Estimate of Cirrus Noise in Herschel Hi-GAL Images

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    In Herschel images of the Galactic plane and many star forming regions, a major factor limiting our ability to extract faint compact sources is cirrus confusion noise, operationally defined as the "statistical error to be expected in photometric measurements due to confusion in a background of fluctuating surface brightness". The histogram of the flux densities of extracted sources shows a distinctive faint-end cutoff below which the catalog suffers from incompleteness and the flux densities become unreliable. This empirical cutoff should be closely related to the estimated cirrus noise and we show that this is the case. We compute the cirrus noise directly, both on Herschel images from which the bright sources have been removed and on simulated images of cirrus with statistically similar fluctuations. We connect these direct estimates with those from power spectrum analysis, which has been used extensively to predict the cirrus noise and provides insight into how it depends on various statistical properties and photometric operational parameters. We report multi-wavelength power spectra of diffuse Galactic dust emission from Hi-GAL observations at 70 to 500 microns within Galactic plane fields at l= 30 degrees and l= 59 degrees. We find that the exponent of the power spectrum is about -3. At 250 microns, the amplitude of the power spectrum increases roughly as the square of the median brightness of the map and so the expected cirrus noise scales linearly with the median brightness. Generally, the confusion noise will be a worse problem at longer wavelengths, because of the combination of lower angular resolution and the rising power spectrum of cirrus toward lower spatial frequencies, but the photometric signal to noise will also depend on the relative spectral energy distribution of the source compared to the cirrus.Comment: 4 pages (in journal), 3 figures, Astronomy and Astrophysics, accepted for publication 13 May 201

    The Role of Anger in Symptoms and Processes of Generalized Anxiety Disorder

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    Research investigating the associations between anger and symptoms of generalized anxiety disorder (GAD) is limited. The goals of the current program of research were to examine the various forms of anger associated with GAD as well as the cross-over effects of worry and anger on cognitive mechanisms characteristic of GAD and high trait anger. In Study 1, participants (N = 381) completed a series of questionnaires assessing various aspects of anger and GAD diagnostic criteria via self-report. Our results indicated that GAD analogues reported higher levels of trait anger, anger suppression, and hostility than less anxious participants. In Study 2, the effects of laboratory-induced anger on negative style, negative beliefs about uncertainty, and worry were examined. Participants were randomized to an anger induction condition (n = 43) or a control condition (n = 34). An interpretation bias task, questionnaire items assessing beliefs about uncertainty, and a structured worry task were administered following the manipulation. Participants in the anger condition reported greater increases in negative interpretive style and in the belief that uncertainty is unfair and spoils everything than participants in the control condition; however no group differences were found with worry. In Study 3, the effects of anger and worry on interpretive style and hostile attributions were examined. Participants were randomized to a worry induction (n = 51), anger induction (n = 50), or control condition (n = 49). We also examined whether GAD analogues reported greater hostile interpretations of ambiguous intent than less anxious participants, and whether GAD analogue status interacted with the worry and anger experimental conditions in predicting increased hostile and threatening interpretations of ambiguous information. Although we found no effects of condition or interactions between GAD and condition on interpretive style or hostile attributions, we found that GAD symptoms were associated with greater negative interpretive style and greater hostile attributions. Together, findings from these studies suggest that elevated levels of multiple dimensions of anger, as well as hostile attributions, characterize individuals who meet diagnostic criteria for GAD and provide some, albeit limited, support for the notion that elevated anger contributes to cognitive vulnerabilities underlying GAD

    Intracellular Transport, Assembly, and Degradation of Wild-Type and Disease-linked Mutant Gap Junction Proteins

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    More than 130 different mutations in the gap junction integral plasma membrane protein connexin32 (Cx32) have been linked to the human peripheral neuropathy X-linked Charcot–Marie–Tooth disease (CMTX). How these various mutants are processed by the cell and the mechanism(s) by which they cause CMTX are unknown. To address these issues, we have studied the intracellular transport, assembly, and degradation of three CMTX-linked Cx32 mutants stably expressed in PC12 cells. Each mutant had a distinct fate: E208K Cx32 appeared to be retained in the endoplasmic reticulum (ER), whereas both the E186K and R142W mutants were transported to perinuclear compartments from which they trafficked either to lysosomes (R142W Cx32) or back to the ER (E186K Cx32). Despite these differences, each mutant was soluble in nonionic detergent but unable to assemble into homomeric connexons. Degradation of both mutant and wild-type connexins was rapid (t1/2 \u3c 3 h) and took place at least in part in the ER by a process sensitive to proteasome inhibitors. The mutants studied are therefore unlikely to cause disease by accumulating in degradation-resistant aggregates but instead are efficiently cleared from the cell by quality control processes that prevent abnormal connexin molecules from traversing the secretory pathway

    Prediabetes and the risk of type 2 diabetes: investigating the roles of depressive and anxiety symptoms in the Lifelines Cohort Study

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    Background Depression and anxiety may increase the risk of progressing from prediabetes to type 2 diabetes. The present study examined the interactions between prediabetes status and elevated depressive and anxiety symptoms with the risk of type 2 diabetes. Methods Participants (N=72,428) were adults aged 40 years and above without diabetes at baseline from the Lifelines Cohort Study (58% female; mean age=51.4 years). The Mini-International Neuropsychiatric Interview screened for elevated symptoms of major depressive disorder and generalized anxiety disorder. Glycated hemoglobin A1c (HbA1c) levels determined prediabetes status at baseline (2007-2013), and HbA1c and self-reported diabetes diagnoses determined diabetes status at follow-up (2014-2017). Groups were formed for elevated depressive and anxiety symptoms, respectively, and prediabetes status at baseline (elevated depressive/anxiety symptoms with prediabetes, elevated depressive/anxiety symptoms alone, and prediabetes alone), and compared to a reference group (no prediabetes or anxiety/depression) on the likelihood of developing diabetes during the follow-up period. Findings N=1,300 (1.8%) participants developed diabetes. While prediabetes alone was associated with incident diabetes (OR=5.94; 95% CI=5.10-6.90, p<.001), the group with combined prediabetes and depressive symptoms had the highest likelihood of developing diabetes over follow-up (OR=8.29; 95% CI=5.58-12.32, p<.001). Similar results were found for prediabetes and anxiety symptoms (OR=6.57; 95% CI=4.62-9.33, p<.001), compared to prediabetes alone (OR=6.09; 95% CI=5.23-7.11, p<.001), though with a smaller effect. The interaction between depressive symptoms and prediabetes was synergistic in age-and-sex adjusted analyses. Conclusion Individuals with elevated depressive, and to some extent anxiety, symptoms in combination with prediabetes may represent a high-risk subgroup for type 2 diabetes

    Connexin32 and X-Linked Charcot-Marie-Tooth Disease

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    This paper deals with the genetic defect responsible for the X-linked form of Charcot-Marie-Tooth disease.Mutations in the gap junction geneconnexin32(Cx32) cause the X-linked form of Charcot–Marie–Tooth disease, an inherited demyelinating neuropathy

    Altered Trafficking of Mutant Connexin32

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    We examined the cellular localization of nine different connexin32 (Cx32) mutants associated with X-linked Charcot–Marie–Tooth disease (CMTX) in communication-incompetent mammalian cells. Cx32 mRNA was made, but little or no protein was detected in one class of mutants. In another class of mutants, Cx32 protein was detectable in the cytoplasm and at the cell surface, where it appeared as plaques and punctate staining. Cx32 immunoreactivity in a third class of mutants was restricted to the cytoplasm, where it often colocalized with the Golgi apparatus. Our studies suggest that CMTX mutations have a predominant effect on the trafficking of Cx32 protein, resulting in a potentially toxic cytoplasmic accumulation of Cx32 in these cells. These results and evidence of cytoplasmic accumulation of other mutated myelin proteins suggest that diseases affecting myelinating cells may share a common pathophysiology

    The Gas Temperature of Starless Cores in Perseus

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    In this paper we study the determinants of starless core temperatures in the Perseus molecular cloud. We use NH3 (1,1) and (2,2) observations to derive core temperatures (T_kin) and data from the COMPLETE Survey of Star Forming Regions and the c2d Spitzer Legacy Survey for observations of the other core and molecular cloud properties. The kinetic temperature distribution probed by NH3 is in the fairly narrow range of 9 - 15 K. We find that cores within the clusters IC348 and NGC1333 are significantly warmer than "field" starless cores, and T_kin is higher within regions of larger extinction-derived column density. Starless cores in the field are warmer when they are closer to class O/I protostars, but this effect is not seen for those cores in clusters. For field starless cores, T_kin is higher in regions in which the 13CO linewidth and the 1.1mm flux from the core are larger, and T_kin is lower when the the peak column density within the core and average volume density of the core are larger. There is no correlation between T_kin and 13CO linewidth, 1.1mm flux, density or peak column density for those cores in clusters. The temperature of the cloud material along the line of sight to the core, as measured by CO or far-infrared emission from dust, is positively correlated with core temperature when considering the collection of cores in the field and in clusters, but this effect is not apparent when the two subsamples of cores are considered separately.Comment: Accepted to ApJ; 13 pages, including 3 tables and three figure

    Evidence for dust evolution within the Taurus Complex from Spitzer images

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    We present Spitzer images of the Taurus Complex (TC) and take advantage of the sensitivity and spatial resolution of the observations to characterize the diffuse IR emission across the cloud. This work highlights evidence of dust evolution within the translucent sections of the archetype reference for studies of quiescent molecular clouds. We combine Spitzer 160 um and IRAS 100 um observations to produce a dust temperature map and a far-IR dust opacity map at 5' resolution. The average dust temperature is about 14.5K with a dispersion of +/-1K across the cloud. The far-IR dust opacity is a factor 2 larger than the average value for the diffuse ISM. This opacity increase and the attenuation of the radiation field (RF) both contribute to account for the lower emission temperature of the large grains. The structure of the TC significantly changes in the mid-IR images that trace emission from PAHs and VSGs. We focus our analysis of the mid-IR emission to a range of ecliptic latitudes where the zodiacal light residuals are small. Within this cloud area, there are no 8 and 24 um counterparts to the brightest 160 um emission features. Conversely, the 8 and 24 um images reveal filamentary structure that is strikingly inconspicuous in the 160 um and extinction maps. The IR colors vary over sub-parsec distances across this filamentary structure. We compare the observed colors with model calculations quantifying the impact of the RF intensity and the abundance of stochastically heated particles on the dust SED. To match the range of observed colors, we have to invoke variations by a factor of a few of both the interstellar RF and the abundance of PAHs and VSGs. We conclude that within this filamentary structure a significant fraction of the dust mass cycles in and out the small size end of the dust size distribution.Comment: 43 pages, 13 figures, accepted for publication in Ap
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