Researchers often examine hydro-climatological processes via Global Circulation Model (GCM) and hydrological model, which have been shown to benefit water resources management and prediction, ...especially at the basin scale. In this study, the Soil and Water Assessment Tool (SWAT) and Statistical Downscaling Method (SDSM) were integrated and applied to estimate streamflows in the Xin River Basin, China, based on climate change scenarios downscaled from different GCMs (BCC-CSM1.1, CanESM2, and NorESM1-M) under three Representative Concentration Pathways (RCPs). Results confirmed that the calibrated SWAT model accurately depicts hydrological processes features at daily, monthly, and yearly scales. Three GCMs based on the calibrated SDSM showed that temperature is continually increasing in the region, however, future precipitation is highly complex and uncertain; there were significant differences among various GCM RCP scenarios. The average of the precipitation in three models showed slight and steady increase trends under RCP2.6 and RCP4.5, but a significant increase under the RCP8.5 scenario. The ensemble average of streamflow in GCMs demonstrated that many RCPs significantly decrease from May to June but increase from August to September relative to the baseline period. The ensemble mean of the multi-GCM indicated that future streamflows under RCP2.6 and RCP4.5 scenarios will be closer to the current streamflow volume. Many RCPs also revealed a significant increase in monthly streamflow dispersion coefficient in October, reflecting a tendency for drought and flood events in that month. The BCC-CSM1.1 and NorESM1-M models showed that streamflows are higher than the baseline with median probability in the future. The low monthly streamflow (10th percentile) processes for each GCM were altogether similar to the baseline, whereas the high monthly streamflows (90th percentile) showed various levels of disparity compared to the baseline.
•Climate data was projected from three CMIP5 GCMs under RCP scenarios using a statistical downscaling model.•Future streamflow was modeled through the calibrated SDSM and SWAT models.•We compared streamflow characteristics in three future periods of the RCPs.
•The northern parts of the Gan River Basin suffer heat wave flash droughts.•The central and southern parts of the basin are prone to precipitation deficit flash droughts.•Precipitation deficit flash ...droughts are more common than heat wave flash droughts in the basin.•Both types of flash droughts have increased significantly since 1997 across the entire basin.•Precipitation deficit flash droughts can develop into prolonged drought events.
As opposed to traditional drought events, flash droughts evolve rapidly and are characterized by soil moisture deficits. The general lack of high resolution soil moisture and evapotranspiration data makes identifying flash droughts at short-term scales (pentads or weeks) nearly impossible, particularly at the basin scale. In this study, we investigated the spatial patterns, temporal characteristics, and related mechanisms of flash droughts in a humid and subtropical basin (Gan River Basin) in China. The variable infiltration capacity (VIC) model can accurately reflect hydrological processes in the Gan River Basin at daily and monthly time scales; here, flash droughts were determined based on VIC outputs (soil moisture and evapotranspiration) and meteorological observations (maximum temperature and precipitation) during the growing season (March-October) from 1961 to 2013. We classified flash droughts into two categories (heat wave and precipitation deficit flash droughts) based on the formation mechanisms. Heat wave flash droughts are high temperature driven events, high temperatures (heat waves) cause evapotranspiration to increase and soil moisture to decrease rapidly. The main driver of precipitation deficit flash droughts is precipitation deficits, which cause soilmoisture to drop and in turn cause evapotranspiration anomalies to decrease and temperature to increase. The northern part of the basin is apparently vulnerable to heat wave flash droughts, whereas precipitation deficit flash droughts tend to occur across the central and southern parts of the basin. Precipitation deficit flash droughts are more common than heat wave flash droughts in general. Both types of flash droughts became significantly more frequent from 1997 to 2013. These increases in both types of flash droughts are likely attributable to climate-related variables such as temperature, precipitation, evapotranspiration, and soil moisture during 1997–2013. As evidenced by our investigation of the evolution of the two types of flash droughts and the example of 2003 summer flash drought across the Gan River Basin, flash droughts can evolve into prolonged droughts.
Stroke is a leading cause of mortality and disability worldwide, with most survivors reporting dysfunctions of motor, sensation, deglutition, cognition, emotion, and speech,
Repetitive transcranial ...magnetic stimulation (rTMS), one of noninvasive brain stimulation (NIBS) techniques, is able to modulate neural excitability of brain regions and has been utilized in neurological and psychiatric diseases. Moreover, a large number of studies have shown that the rTMS presents positive effects on function recovery of stroke patients. In this review, we would like to summarized the clinical benefits of rTMS for stroke rehabilitation, including improvements of motor impairment, dysphagia, depression, cognitive function, and central post-stroke pain. In addition, this review will also discuss the molecular and cellular mechanisms underlying rTMS-mediated stroke rehabilitation, especially immune regulatory mechanisms, such as regulation of immune cells and inflammatory cytokines. Moreover, the neuroimaging technique as an important tool in rTMS-mediated stroke rehabilitation has been discussed, to better understanding the mechanisms underlying the effects of rTMS. Finally, the current challenges and future prospects of rTMS-mediated stroke rehabilitation are also elucidated with the intention to accelerate its widespread clinical application.
In this study, the precursor precipitates of Zinc oxide (ZnO) were obtained by a direct precipitation method via the reaction between Zinc nitrate (Zn(NO
3)
2) and Ammonium carbonate ((NH
4)
2CO
3) ...in aqueous solutions with proper concentration. X-ray diffraction (XRD) analysis demonstrated that the precursor precipitates of ZnO were Zn
4(CO
3)(OH)
6·H
2O. Both the Differential thermal analysis (DTA) and the thermal gravimetric analysis (TGA) curves of the precursor precipitates show that no further weight loss and thermal effect were observed at a temperature of above 550
°C. The precursor precipitates of ZnO were subjected to thermal calcinations and finally yielded the nano-sized ZnO powders. The calcined ZnO powders were characterized by XRD, Brunauer–Emmet–Teller analysis (BET), and scanning electron microscope (SEM), respectively. The XRD results indicated that the synthesized ZnO powders had a pure wurtzite structure and the average nano-particle sizes were about 35.2
nm. However, the inconsistency of ZnO particle sizes derived from the BET methods and the XRD analysis indicated that a fraction of nano-sized ZnO powders were in the form of aggregates, which was also verified by SEM and TEM image. In addition, both the SEM image and the TEM photograph demonstrated that the nano-sized ZnO particles were of a pseudo-spherical shape.
Eco-friendly thiospinel-type CuCo
2
S
4
material has been investigated as a potential thermoelectric material. The temperature,
T
, dependence of electrical resistivity,
ρ
, of CuCo
2
S
4
shows a ...metallic conductivity (∂
ρ
/∂
T
> 0) and a strong degenerate state, in the range of 323–723 K. Besides a high carrier concentration consistent with the metallic nature, its Hall mobility is still unexpectedly estimated to be 8.5 cm
2
V
−1
s
−1
at room temperature. The positive Seebeck coefficient
S
confirms a
p
-type carrier conduction. Similar to most of the transition-metal spinel chalcogenides, the
S
value is very low, 12–36 μV K
−1
at 323–723 K. As a result, a relatively low power factor
PF
&!thinsp; ∼ 0.35 mW m
−1
K
−2
was obtained at 723 K. Due to the dominant role of electronic thermal conductivity, the total thermal conductivity
к
was high and increases with a linear dependence on
T
. However, the intrinsic lattice conductivity
к
l
was relatively low, ranging from 1.48 W m
−1
K
−1
at 323 K to 0.57 W m
−1
K
−1
at 723 K. It follows there is a
T
−1
dependence indicative of Umklapp type phonon–phonon interaction. Importantly, the intrinsically low
к
l
in CuCo
2
S
4
is attributed to multiple mechanisms, mainly including the large unit cell with primarily octahedral coordination, the high distortion and complexity of the structure, and additional interfacial thermal resistance.
Compound precipitation and wind speed extremes can significantly impact ecosystems, socio-economies, and human health. The characteristics of precipitation or wind speed extremes have been ...extensively studied, however, concurrent precipitation and wind speed extremes have received very little attention to date. This study focused on the characteristics of concurrent precipitation and wind speed extremes from 1981 to 2018 in China based on daily precipitation and maximum wind speed observations. The results showed that concurrent precipitation and wind speed extremes were most likely to occur in southern China, especially in the southeast coastal areas (frequent tropical cyclones). The concurrent extremes showed a downward trend in 1981–2010 followed by an upward trend in 2011–2018. The reversal of the concurrent extremes around 2011 may be related to the increase in individual extreme precipitation and wind speed. We divided the concurrent extremes into four grades based on the magnitudes: mild, moderate, severe, and extreme. Concurrent extremes of all four grades all reversed around 2011; the mild and moderate events in particular showed significant increasing trends from 2011 to 2018. High percentages (more than 50%) of concurrent precipitation and wind extremes were found in summer months. We ranked the top 10 concurrent precipitation and wind speed extremes in 1981–2018 by magnitude to observe their spatial characteristics. We analyzed the mechanisms of the strongest concurrent event (top 1 on August 19, 1997) and the most recent concurrent event (top 2 on July 20, 2016) to conclude that the typhoon and strong convective weather systems can cause high-magnitude concurrent precipitation and wind speed extremes.
•Southern China is susceptible to concurrent precipitation and wind extremes.•High percentages of concurrent precipitation and wind extremes are found in summer.•Reversal trends in concurrent extremes are common in terms of mild and moderate events.•Top 10 concurrent extremes were identified by magnitude from 1981 to 2018.•Typhoon and strong convective weather systems can cause severe concurrent extremes.
The ability to detect and respond to acute oxygen (O2) shortages is indispensable to aerobic life. The molecular mechanisms and circuits underlying this capacity are poorly understood. Here, we ...characterize the behavioral responses of feeding Caenorhabditis elegans to approximately 1% O2. Acute hypoxia triggers a bout of turning maneuvers followed by a persistent switch to rapid forward movement as animals seek to avoid and escape hypoxia. While the behavioral responses to 1% O2 closely resemble those evoked by 21% O2, they have distinct molecular and circuit underpinnings. Disrupting phosphodiesterases (PDEs), specific G proteins, or BBSome function inhibits escape from 1% O2 due to increased cGMP signaling. A primary source of cGMP is GCY-28, the ortholog of the atrial natriuretic peptide (ANP) receptor. cGMP activates the protein kinase G EGL-4 and enhances neuroendocrine secretion to inhibit acute responses to 1% O2. Triggering a rise in cGMP optogenetically in multiple neurons, including AIA interneurons, rapidly and reversibly inhibits escape from 1% O2. Ca2+ imaging reveals that a 7% to 1% O2 stimulus evokes a Ca2+ decrease in several neurons. Defects in mitochondrial complex I (MCI) and mitochondrial complex I (MCIII), which lead to persistently high reactive oxygen species (ROS), abrogate acute hypoxia responses. In particular, repressing the expression of isp-1, which encodes the iron sulfur protein of MCIII, inhibits escape from 1% O2 without affecting responses to 21% O2. Both genetic and pharmacological up-regulation of mitochondrial ROS increase cGMP levels, which contribute to the reduced hypoxia responses. Our results implicate ROS and precise regulation of intracellular cGMP in the modulation of acute responses to hypoxia by C. elegans.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Brain tissue from familial dysautonomia (FD) patients show tRNA modification defects.•Fibroblast cell lines from FD patients show tRNA modification defects.•Levels of the tRNA wobble nucleoside ...mcm5s2U is reduced in FD patients.
Familial dysautonomia (FD) is a recessive neurodegenerative genetic disease. FD is caused by a mutation in the IKBKAP gene resulting in a splicing defect and reduced levels of full length IKAP protein. IKAP homologues can be found in all eukaryotes and are part of a conserved six subunit protein complex, Elongator complex. Inactivation of any Elongator subunit gene in multicellular organisms cause a wide range of phenotypes, suggesting that Elongator has a pivotal role in several cellular processes. In yeast, there is convincing evidence that the main role of Elongator complex is in formation of modified wobble uridine nucleosides in tRNA and that their absence will influence translational efficiency. To date, no study has explored the possibility that FD patients display defects in formation of modified wobble uridine nucleosides as a consequence of reduced IKAP levels. In this study, we show that brain tissue and fibroblast cell lines from FD patients have reduced levels of the wobble uridine nucleoside 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U). Our findings indicate that FD could be caused by inefficient translation due to lower levels of wobble uridine nucleosides.
Interleukin-17 (IL-17) is a major pro-inflammatory cytokine: it mediates responses to pathogens or tissue damage, and drives autoimmune diseases. Little is known about its role in the nervous system. ...Here we show that IL-17 has neuromodulator-like properties in Caenorhabditis elegans. IL-17 can act directly on neurons to alter their response properties and contribution to behaviour. Using unbiased genetic screens, we delineate an IL-17 signalling pathway and show that it acts in the RMG hub interneurons. Disrupting IL-17 signalling reduces RMG responsiveness to input from oxygen sensors, and renders sustained escape from 21% oxygen transient and contingent on additional stimuli. Over-activating IL-17 receptors abnormally heightens responses to 21% oxygen in RMG neurons and whole animals. IL-17 deficiency can be bypassed by optogenetic stimulation of RMG. Inducing IL-17 expression in adults can rescue mutant defects within 6 h. These findings reveal a non-immunological role of IL-17 modulating circuit function and behaviour.
Background Previous studies have shown social activity is associated with reduced risk of health outcomes. However, among older people (≥65 years) who were socially inactive at baseline, limited ...study explored whether increased participation in social activity in later life was associated with reduced risk of health outcomes; therefore, using the data from the Chinese Longitudinal Healthy Longevity Survey, the study was performed. Methods The study outcomes were 10-year all-cause mortality (sample number = 9,984) and 10-year heart diseases (sample number = 7,496). The exposure was the change of social activity frequency. Cox regression analysis was used for data analysis. Results During the follow-up, there were 6,407 all-cause mortalities and 1,035 heart diseases, respectively. Kaplan–Meier analysis demonstrated that cumulative incidences of all-cause mortality were significantly lower in participants with changes into more frequent social activity (log-rank p < 0.001), while no significant difference was observed for heart diseases (log-rank p = 0.330). Compared with the subgroup who never participated in social activity at baseline, adjusted HRs of all-cause mortality were 0.79 (95% CI: 0.70–0.90, p < 0.001), 0.78 (95% CI: 0.63–0.96, p = 0.019), 0.74 (0.59–0.92, p = 0.006), and 0.70 (95% CI: 0.56–0.88, p = 0.002) for the subgroup of switching to sometimes, the subgroup of switching to once a month, the subgroup of switching to once a week, and the subgroup of switching to everyday, respectively. The corresponding HRs of heart diseases were 0.83 (95% CI: 0.65–1.08, p = 0.170), 0.82 (95% CI: 0.51–1.31, p = 0.412), 0.91 (0.58–1.42, p = 0.675) and 0.75 (95% CI: 0.47–1.20, p = 0.227), respectively. Stratified and sensitivity analyses revealed similar results. Conclusion Among older people who never participated in social activity, increased participation in social activity in later life was associated with reduced risk of all-cause mortality, but was not associated with reduced risk of heart diseases.
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