4,4′-[Piperazine-1,4-diylbis(propyl­ene­nitrilo­methyl­idyne)]diphenol

In the title mol­ecule, C24H32N4O2, the piperazine ring adopts a chair conformation and the dihedral angle between the two benzene rings is 35.4 (1)°. In the crystal structure, inter­molecular O—H⋯N hydrogen bonds link mol­ecules into chains along [001]

Energy efficiency and environmental degradation nexus: evidence from the Quantile-on-Quantile regression technique

The world is facing enormous challenge of climate change and global warming due to increased emission level. In order to overcome such challenges, economies are adopting energy efficient techniques to control the carbon emissions and improves environmental sustainability. This study analyses the influencing factors of environmental quality from a global perspective throughout the last three decades. In this regard, advanced time series approaches are used to identify the association between factors such as economic growth, energy efficiency (E.N.E.F.), and carbon emissions – covering global data over the period 1990Q4–2020Q4. From the time series methods, this study observed the stationarity of all variables at first difference. The empirical outcomes also validates the long-run equilibrium relationship between the variables. Due to asymmetric distribution of the variables, this study uses the novel Quantile-on-Quantile (Q.Q.) regression approach, which reveals that increasing economic growth harms environmental quality by increasing the carbon emissions level. However, E.N.E.F. is a prominent factor of environmental sustainability, that reduces the level of carbon emissions in the atmosphere. Employing the pairwise Granger causality test, this study observed the unidirectional causality from economic growth to carbon emissions, while a two-way causal nexus is found between economic growth – E.N.E.F. and E.N.E.F. – carbon emissions. Based on the empirical results, this study suggests that economic growth should be regulated in a sense that it contribute towards the improvement of E.N.E.F., which ultimately leads to reduce the emissions level and promote environmental sustainability

Greater Bud Outgrowth of Bromus inermis than Pascopyrum smithii Under Multiple Environmental Conditions

Tiller recruitment of perennial grasses in mixed-grass prairie primarily occurs from belowground buds. Environmental conditions, such as temperature, soil moisture and grazing can affect bud outgrowth of both invasive and native perennial grasses. Differential bud outgrowth responses of native and invasive species to climate change and grazing could alter competitive interactions that have implications for future land management. The aims of this work were to (i) compare how spring temperature altered bud outgrowth of native Pascopyrum smithii (Rydb.) Á. Löve (western wheatgrass) and introduced Bromus inermis Leyss.(smooth brome), (ii) compare how watering frequency altered bud outgrowth of these two species and (iii) evaluate how clipping interacts with spring temperature or watering frequency to affect P. smithii bud outgrowth

Curvature regularization for Non-line-of-sight Imaging from Under-sampled Data

Non-line-of-sight (NLOS) imaging aims to reconstruct the three-dimensional hidden scenes from the data measured in the line-of-sight, which uses photon time-of-flight information encoded in light after multiple diffuse reflections. The under-sampled scanning data can facilitate fast imaging. However, the resulting reconstruction problem becomes a serious ill-posed inverse problem, the solution of which is of high possibility to be degraded due to noises and distortions. In this paper, we propose two novel NLOS reconstruction models based on curvature regularization, i.e., the object-domain curvature regularization model and the dual (i.e., signal and object)-domain curvature regularization model. Fast numerical optimization algorithms are developed relying on the alternating direction method of multipliers (ADMM) with the backtracking stepsize rule, which are further accelerated by GPU implementation. We evaluate the proposed algorithms on both synthetic and real datasets, which achieve state-of-the-art performance, especially in the compressed sensing setting. All our codes and data are available at https://github.com/Duanlab123/CurvNLOS

The impact of an abandoned mercury mine on the environment in the Xiushan region, Chongqing, southwestern China

Mercury contamination is a serious problem in the Hg mining area of Xiushan County, Chongqing, southwestern China. The concentrations of total mercury (THg) and methylmercury (MeHg) in paddy soil, surface water, and rice (grain) samples were determined to investigate the regional distribution of Hg contamination. Simultaneously, gaseous elemental Hg (GEM) in ambient air near the sampling sites was measured. The total Hg concentrations in surface water were highly elevated, ranging from 13 to 2390 ng/L, and the total MeHg concentrations varied between 0.17 and 1.1 ng/L. The dissolved Hg and MeHg concentrations in surface water ranged from 4.7 to 470 ng/L and 0.14–0.35 ng/L, respectively. High THg and MeHg concentrations were also obtained in paddy soils from mining areas, ranging from 0.45 to 68 μg/g and 0.13–4.8 ng/g, respectively. Similar to the high concentrations in water and soil, the THg concentration in rice (grain) ranged from 4.7 to 550 ng/g and MeHg from 2.9 to 26 ng/g. Elevated Hg concentrations in rice, as a staple food of local residents, confirmed that rice consumption could be a vital pathway for MeHg exposure to native people. Humic acid and fulvic acid had significant correlations with soil MeHg, implying that they have important roles that influence MeHg production in soil. The spatial distribution characteristics of Hg and MeHg pollution in the local environment indicated their origins from historic Hg mining sites in the Xiushan area.acceptedVersio

The impact of an abandoned mercury mine on the environment in the Xiushan region, Chongqing, southwestern China

Mercury contamination is a serious problem in the Hg mining area of Xiushan County, Chongqing, southwestern China. The concentrations of total mercury (THg) and methylmercury (MeHg) in paddy soil, surface water, and rice (grain) samples were determined to investigate the regional distribution of Hg contamination. Simultaneously, gaseous elemental Hg (GEM) in ambient air near the sampling sites was measured. The total Hg concentrations in surface water were highly elevated, ranging from 13 to 2390 ng/L, and the total MeHg concentrations varied between 0.17 and 1.1 ng/L. The dissolved Hg and MeHg concentrations in surface water ranged from 4.7 to 470 ng/L and 0.14–0.35 ng/L, respectively. High THg and MeHg concentrations were also obtained in paddy soils from mining areas, ranging from 0.45 to 68 μg/g and 0.13–4.8 ng/g, respectively. Similar to the high concentrations in water and soil, the THg concentration in rice (grain) ranged from 4.7 to 550 ng/g and MeHg from 2.9 to 26 ng/g. Elevated Hg concentrations in rice, as a staple food of local residents, confirmed that rice consumption could be a vital pathway for MeHg exposure to native people. Humic acid and fulvic acid had significant correlations with soil MeHg, implying that they have important roles that influence MeHg production in soil. The spatial distribution characteristics of Hg and MeHg pollution in the local environment indicated their origins from historic Hg mining sites in the Xiushan area.acceptedVersio

Alterations of Sub-cortical Gray Matter Volume and Their Associations With Disease Duration in Patients With Restless Legs Syndrome

Object: The purpose of this study was to uncover the pathology of restless legs syndrome (RLS) by exploring brain structural alterations and their corresponding functional abnormality.Method: Surface-based morphometry (SBM) and voxel-based morphometry (VBM) were performed to explore the alterations in cortical and sub-cortical gray matter volume (GMV) in a cohort of 20 RLS and 18 normal controls (NC). Furthermore, resting-state functional connectivity (RSFC) was also performed to identify the functional alterations in patients with RLS.Results: We found significant alterations of sub-cortical GMV, especially the bilateral putamen (PUT), rather than alterations of cortical GMV in patients with RLS compared to NC using both SBM and VBM. Further sub-regional analysis revealed that GMV alterations of PUT was mostly located in the left dorsal caudal PUT in patients with RLS. In addition, altered RSFC patterns of PUT were identified in patients with RLS compared to NC. Moreover, correlation analyses showed that the GMV of the left caudate and the left ventral rostral PUT were positively correlated with disease duration in patients with RLS.Conclusions: The alterations of subcortical GMV might imply that the primarily affected areas are located in sub-cortical areas especially in the sub-region of PUT by the pathologic process of RLS, which might be used as potential biomarkers for the early diagnosis of RLS