157 research outputs found
Increasing Atmospheric Humidity and CO\u3csub\u3e2\u3c/sub\u3e Concentration Alleviate Forest Mortality Risk
Climate-induced forest mortality is being increasingly observed throughout the globe. Alarmingly, it is expected to exacerbate under climate change due to shifting precipitation patterns and rising air temperature. However, the impact of concomitant changes in atmospheric humidity and CO2 concentration through their influence on stomatal kinetics remains a subject of debate and inquiry. By using a dynamic soil–plant–atmosphere model, mortality risks associated with hydraulic failure and stomatal closure for 13 temperate and tropical forest biomes across the globe are analyzed. The mortality risk is evaluated in response to both individual and combined changes in precipitation amounts and their seasonal distribution, mean air temperature, specific humidity, and atmospheric CO2 concentration. Model results show that the risk is predicted to significantly increase due to changes in precipitation and air temperature regime for the period 2050–2069. However, this increase may largely get alleviated by concurrent increases in atmospheric specific humidity and CO2 concentration. The increase in mortality risk is expected to be higher for needleleaf forests than for broadleaf forests, as a result of disparity in hydraulic traits. These findings will facilitate decisions about intervention and management of different forest types under changing climate
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Restraint use and risky driving behaviors across drug types and drug and alcohol combinations for drivers involved in a fatal motor vehicle collision on U.S. roadways
Background
While driving impaired is a well-recognized risk factor for motor vehicle (MV) crash, recent trends in recreational drug use and abuse may pose increased threats to occupant safety. This study examines mechanisms through which drug and/or alcohol combinations contribute to fatal MV crash.
Methods
The Fatality Analysis Reporting System (FARS) for 2008–2013 was used to examine drugs, alcohol, driver restraint use, driver violations/errors and other behaviors of drivers of passenger vehicles who were tested for both alcohol and drugs (n = 79,932). Statistical analysis was based on Chi-square tests and multivariable logistic regression. Associations of restraint use and other outcomes with alcohol and drug use were measured by estimated odds ratios (ORs) and 95 % confidence intervals (95 % CIs).
Results
More than half (54.8 %) of the study population were positive for drugs or alcohol at the time of crash. Approximately half of drivers were belted, but this varied from 67.1 % (unimpaired) to 33.0 % (drugs plus alcohol). Compared to the unimpaired, the odds of a driver being unbelted varied: alcohol and cannabis (OR 3.70, 95 % CI 3.44–3.97), alcohol only (3.50,3.36–3.65), stimulants (2.13,1.91–2.38), depressants (2.09,1.89–2.31), narcotics (1.84,1.67–2.02) and cannabis only (1.55,1.43–1.67). Compared to belted drivers, unbelted drivers were over 4 times more likely to die. Driving violations varied across drug/drug alcohol combinations. Speed-related violations were higher for drivers positive for stimulants, alcohol, cannabis, and cannabis plus alcohol, with a more than two fold increase for alcohol and cannabis (2.36, 2.05, 2.71).
Conclusions
Mechanisms through which drugs, alcohol and substance combinations produce increased risks to occupant safety include lowered restraint use and increases in risky driving behaviors, including speeding, lane, passing, turning and signal/sign violations
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Restraint use and risky driving behaviors across drug types and drug and alcohol combinations for drivers involved in a fatal motor vehicle collision on U.S. roadways
Background
While driving impaired is a well-recognized risk factor for motor vehicle (MV) crash, recent trends in recreational drug use and abuse may pose increased threats to occupant safety. This study examines mechanisms through which drug and/or alcohol combinations contribute to fatal MV crash.
Methods
The Fatality Analysis Reporting System (FARS) for 2008–2013 was used to examine drugs, alcohol, driver restraint use, driver violations/errors and other behaviors of drivers of passenger vehicles who were tested for both alcohol and drugs (n = 79,932). Statistical analysis was based on Chi-square tests and multivariable logistic regression. Associations of restraint use and other outcomes with alcohol and drug use were measured by estimated odds ratios (ORs) and 95 % confidence intervals (95 % CIs).
Results
More than half (54.8 %) of the study population were positive for drugs or alcohol at the time of crash. Approximately half of drivers were belted, but this varied from 67.1 % (unimpaired) to 33.0 % (drugs plus alcohol). Compared to the unimpaired, the odds of a driver being unbelted varied: alcohol and cannabis (OR 3.70, 95 % CI 3.44–3.97), alcohol only (3.50,3.36–3.65), stimulants (2.13,1.91–2.38), depressants (2.09,1.89–2.31), narcotics (1.84,1.67–2.02) and cannabis only (1.55,1.43–1.67). Compared to belted drivers, unbelted drivers were over 4 times more likely to die. Driving violations varied across drug/drug alcohol combinations. Speed-related violations were higher for drivers positive for stimulants, alcohol, cannabis, and cannabis plus alcohol, with a more than two fold increase for alcohol and cannabis (2.36, 2.05, 2.71).
Conclusions
Mechanisms through which drugs, alcohol and substance combinations produce increased risks to occupant safety include lowered restraint use and increases in risky driving behaviors, including speeding, lane, passing, turning and signal/sign violations
Imaging molecular orbitals with laser-induced electron tunneling spectroscopy
Photoelectron spectroscopy in intense laser fields has proven to be a
powerful tool for providing detailed insights into molecular structure. The
ionizing molecular orbital, however, has not been reconstructed from the
photoelectron spectra, mainly due to the fact that its phase information can be
hardly extracted. In this work, we propose a method to retrieve the phase
information of the ionizing molecular orbital with laser-induced electron
tunneling spectroscopy. By analyzing the interference pattern in the
photoelectron spectrum, the weighted coefficients and the relative phases of
the constituent atomic orbitals for a molecular orbital can be extracted. With
this information we reconstruct the highest occupied molecular orbital of
N. Our work provides a reliable and general approach for imaging of
molecular orbitals with the photoelectron spectroscopy.Comment: 6 pages, 4 figures, including Supplementary Material
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Large Divergence of Projected High Latitude Vegetation Composition and Productivity Due To Functional Trait Uncertainty
Vegetation distribution and composition are expected to change in northern high latitudes under rapid warming, which regulates ecosystem functions but remains challenging to predict. Vegetation change arises from the interplay of chronic climate trends such as warming and transient demographic processes of recruitment, growth, competition, and mortality. Most predictive models overlooked the role of demographic dynamics controlled by plant traits. Here, we simulate vegetation dynamics at the Kougarok Hillslope site in Alaska under historical and future climates using the E3SM Land Model coupled to the Functionally Assembled Terrestrial Simulator (ELM-FATES). To evaluate the roles of plant traits, we parameterize the model with 5,265 trait configurations representing diverse physiological and demographic strategies. Results show current modeled biomass, composition, and productivity are most sensitive to traits controlling photosynthetic capacity, carbon allocation, allometry, and phenology. Among all trait configurations, ∼5% reproduce in situ biomass and plant functional type (PFT) composition measured in 2016, that are indistinguishable from these two observed ecosystem states. Notably, these same trait configurations produce diverging biomass, composition, and productivity under future climate, where the uncertainty attributable to traits is twice the change attributable to climate change. The variation of projected productivity arises from emerging PFT composition under novel climate regimes, primarily explained by traits controlling cold-induced mortality, recruitment, and allometry. Our findings highlight the importance and uncertainty of demographic dynamics and its interaction with climate change in shaping Arctic vegetation change. Improved model predictions will likely benefit from explicit consideration of vegetation demography and better constraints of critical traits
Laser-sub-cycle two-dimensional electron momentum mapping using orthogonal two-color fields
The two-dimensional sub-cycle-time to electron momentum mapping provided by
orthogonal two-color laser fields is applied to photoelectron spectroscopy.
Using neon as the example we gain experimental access to the dynamics of
emitted electron wave packets in electron momenta spectra measured by
coincidence momentum imaging. We demonstrate the opportunities provided by this
time-to-momentum mapping by investigating the influence of the parent ion on
the emitted electrons on laser-sub-cycle times. It is found that depending on
their sub-cycle birth time the trajectories of photoelectrons are affected
differently by the ion's Coulomb field
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Protective Role of Rho Guanosine Diphosphate Dissociation Inhibitor, Ly-GDI, in Pulmonary Alveolitis
Growing evidences indicate that Ly-GDI, an inhibitory protein of Rho GTPases, plays an essential role in regulating actin cytoskeletal alteration which is indispensible for the process such as phagocytosis. However, the role of Ly-GDI in inflammation remains largely unknown. In the current study, we found that Ly-GDI expression was significantly decreased in the IgG immune complex-injured lungs. To determine if Ly-GDI might regulate the lung inflammatory response, we constructed adenovirus vectors that could mediate ectopic expression of Ly-GDI (Adeno-Ly-GDI). In vivo mouse lung expression of Ly-GDI resulted in a significant attenuation of IgG immune complex-induced lung injury, which was due to the decreased pulmonary permeability and lung inflammatory cells, especially neutrophil accumulation. Upon IgG immune complex deposition, mice with Ly-GDI over-expression in the lungs produced significant less inflammatory mediators (TNF-α, IL-6, MCP-1, and MIP-1α) in bronchoalveolar lavage fluid when compared control mice receiving airway injection of Adeno-GFP. Mechanically, IgG immune complex-induced NF-κB activity was markedly suppressed by Ly-GDI in both alveolar macrophages and lungs as measured by luciferase assay and electrophoretic mobility shift assay. These findings suggest that Ly-GDI is a critical regulator of inflammatory injury after deposition of IgG immune complexes and that it negatively regulates the lung NF-κB activity
Spatiotemporal Fusion of Land Surface Temperature Based on a Convolutional Neural Network
© 1980-2012 IEEE. Due to the tradeoff between spatial and temporal resolutions commonly encountered in remote sensing, no single satellite sensor can provide fine spatial resolution land surface temperature (LST) products with frequent coverage. This situation greatly limits applications that require LST data with fine spatiotemporal resolution. Here, a deep learning-based spatiotemporal temperature fusion network (STTFN) method for the generation of fine spatiotemporal resolution LST products is proposed. In STTFN, a multiscale fusion convolutional neural network is employed to build the complex nonlinear relationship between input and output LSTs. Thus, unlike other LST spatiotemporal fusion approaches, STTFN is able to form the potentially complicated relationships through the use of training data without manually designed mathematical rules making it is more flexible and intelligent than other methods. In addition, two target fine spatial resolution LST images are predicted and then integrated by a spatiotemporal-consistency (STC)-weighting function to take advantage of STC of LST data. A set of analyses using two real LST data sets obtained from Landsat and moderate resolution imaging spectroradiometer (MODIS) were undertaken to evaluate the ability of STTFN to generate fine spatiotemporal resolution LST products. The results show that, compared with three classic fusion methods [the enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM), the spatiotemporal integrated temperature fusion model (STITFM), and the two-stream convolutional neural network for spatiotemporal image fusion (StfNet)], the proposed network produced the most accurate outputs [average root mean square error (RMSE) 0.971]
Association of vitamin D deficiency and subclinical diabetic peripheral neuropathy in type 2 diabetes patients
BackgroundDiabetic peripheral neuropathy (DPN) contributes to disability and imposes heavy burdens, while subclinical DPN is lack of attention so far. We aimed to investigate the relationship between vitamin D and distinct subtypes of subclinical DPN in type 2 diabetes (T2DM) patients.MethodsThis cross-sectional study included 3629 T2DM inpatients who undertook nerve conduction study to detect subclinical DPN in Zhongshan Hospital between March 2012 and December 2019. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D (25(OH)D) level < 50 nmol/L.Results1620 (44.6%) patients had subclinical DPN and they were further divided into subgroups: distal symmetric polyneuropathy (DSPN) (n=685), mononeuropathy (n=679) and radiculopathy (n=256). Compared with non-DPN, DPN group had significantly lower level of 25(OH)D (P < 0.05). In DPN subtypes, only DSPN patients had significantly lower levels of 25(OH)D (36.18 ± 19.47 vs. 41.03 ± 18.47 nmol/L, P < 0.001) and higher proportion of vitamin D deficiency (78.54% vs. 72.18%, P < 0.001) than non-DPN. Vitamin D deficiency was associated with the increased prevalence of subclinical DPN [odds ratio (OR) 1.276, 95% confidence interval (CI) 1.086-1.501, P = 0.003] and DSPN [OR 1. 646, 95% CI 1.31-2.078, P < 0.001], independent of sex, age, weight, blood pressure, glycosylated hemoglobin, T2DM duration, calcium, phosphorus, parathyroid hormone, lipids and renal function. The association between vitamin D deficiency and mononeuropathy or radiculopathy was not statistically significant. A negative linear association was observed between 25(OH)D and subclinical DSPN. Vitamin D deficiency maintained its significant association with subclinical DSPN in all age groups.ConclusionsVitamin D deficiency was independently associated with subclinical DSPN, rather than other DPN subtypes
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