Dust storms cause a wide range of impacts on environment, economy and human health in the Sistan region of southeastern Iran. This paper investigates long-term variability of dust activity over ...23 years (1997–2019) using the Dust Storm Index (DSI) and the frequency of dust-storm days (DSD, visibility <1000 m) and assesses the associated importance of various terrestrial and climatic drivers. A dust storm corridor was identified, based on the prevailing wind direction at Zabol, including parts of the Hamoun lakes and surrounding desert in order to study the effects of vegetation cover and lake water levels on dust activity. The results show maximum intensity of dust storms occurred at 10:30 a.m. and in the summer, consistent with the highest wind speeds – associated with the regionally important Levar wind – and highest air temperatures and lowest precipitation and relative humidity. Strong positive correlations were demonstrated between DSI and wind speed, particularly in summer. The 2000–2004 period saw severe dust-raising activity with a DSI of 530.6. Mean wind speeds were greater and precipitation, humidity, vegetation and water coverage were lower during this severe dust-activity period than in other periods. Comparing 2000–2004 with 1997–1999, DSI was five times higher and DSD eight times higher. The dust storms with the longest duration occurred in July 2001 and June 2008 (114 h and 78 h respectively). The July 2001 event, in which wind speed peaked at 25 m/s and visibility dropped to 100 m on several occasions, may be the longest continuous dust storm on record. The key role of water and vegetation cover in the Hamouns was highlighted, indicating the importance of protecting the Hamoun ecosystems and sustainably managing their water resources in efforts to mitigate dust storm hazards in the Sistan region.
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•The maximum intensity of dust storms occurred in June, July and August.•The 2000–2004 period saw particularly severe dust-activity.•The longest continuous dust storm on record occurred at Zabol in July 2001.•Positive and strong correlations were observed between DSI and wind speed.•High wind speed, low precipitation and low vegetation cover increased dust activity.
The medial occipital lobe, composed of the lingual gyrus and cuneus, is necessary for both basic and higher level visual processing. It is also known to facilitate cross-modal, nonvisual functions, ...such as linguistic processing and verbal memory, after the loss of the visual senses. A detailed cortical model elucidating the white matter connectivity associated with this area could improve our understanding of the interacting brain networks that underlie complex human processes and postoperative outcomes related to vision and language.
Generalized q-sampling imaging tractography, validated by gross anatomic dissection for qualitative visual agreement, was performed on 10 healthy adult controls obtained from the Human Connectome Project.
Major white matter connections were identified by tractography and validated by gross dissection, which connected the medial occipital lobe with itself and the adjacent cortices, especially the temporal lobe. The short- and long-range connections identified consisted mainly of U-shaped association fibers, intracuneal fibers, and inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, middle longitudinal fasciculus, and lingual–fusiform connections.
The medial occipital lobe is an extremely interconnected system, supporting its ability to perform coordinated basic visual processing, but also serves as a center for many long-range association fibers, supporting its importance in nonvisual functions, such as language and memory. The presented data represent clinically actionable anatomic information that can be used in multimodal navigation of white matter lesions in the medial occipital lobe to prevent neurologic deficits and improve patients' quality of life after cerebral surgery.
•Comprehensive monitoring and assessment of the 2022 YRC extreme drought based on GRACE-based drought severity drought (GRACE-DSI).•Spatiotemporal evolution of the 2022 YRC drought was ...analyzed.•GRACE-DSI was validated from multi-source in-situ measurements.•Possible cause and mechanism of the 2022 YRC drought was revealed.
Under global warming, extreme climatic events frequently occurred worldwide such as extreme drought and heavy flood. Analysis of drought and flood spatiotemporal evolution and physical mechanism is of great significance for future disaster warning and mitigation. In 2022, the Yangtze River Catchment (YRC) experienced an extreme drought, which profoundly affected the regional economy, ecological environment and anthropogenic activities. In this study, we quantified the spatiotemporal characteristics of terrestrial water storage anomalies (TWSA) response to this severe drought event using Gravity Recovery and Climate Experiment-based drought severity index (GRACE-DSI), with the inspection of hydrological model and in-situ measurements. The results showed that the 2022 YRC drought first occurred in July at the upstream and midstream, then spread to downstream and finally occupied almost the whole YRC in August and ∼ 94% of the YRC in September. The effectiveness of GRACE-DSI for drought monitor can be validated by in-situ hydrological and meteorological observations. Good correlations among El Niño-Southern Oscillation (ENSO), precipitation anomalies (PA), and TWSA were found, demonstrating the regional atmospheric circulation anomaly was the driving factor of this extreme drought event, which triggered the changes in precipitation further to influence the pattern of terrestrial water storage. The consecutive La Niña events induced the extension of western Pacific subtropical high (WPSH) and Iranian high, the precipitation deficiency in 2022 summer declined by ∼ 46% and ∼ 36% compared to 2020 and 2021 respectively, which was the main cause of the extreme drought.
Perhaps more than any other “-omics” endeavor, the accuracy and level of detail obtained from mapping the major connection pathways in the living human brain with diffusion MRI depend on the ...capabilities of the imaging technology used. The current tools are remarkable; allowing the formation of an “image” of the water diffusion probability distribution in regions of complex crossing fibers at each of half a million voxels in the brain. Nonetheless our ability to map the connection pathways is limited by the image sensitivity and resolution, and also the contrast and resolution in encoding of the diffusion probability distribution.
The goal of our Human Connectome Project (HCP) is to address these limiting factors by re-engineering the scanner from the ground up to optimize the high b-value, high angular resolution diffusion imaging needed for sensitive and accurate mapping of the brain's structural connections. Our efforts were directed based on the relative contributions of each scanner component. The gradient subsection was a major focus since gradient amplitude is central to determining the diffusion contrast, the amount of T2 signal loss, and the blurring of the water PDF over the course of the diffusion time. By implementing a novel 4-port drive geometry and optimizing size and linearity for the brain, we demonstrate a whole-body sized scanner with Gmax=300mT/m on each axis capable of the sustained duty cycle needed for diffusion imaging. The system is capable of slewing the gradient at a rate of 200T/m/s as needed for the EPI image encoding. In order to enhance the efficiency of the diffusion sequence we implemented a FOV shifting approach to Simultaneous MultiSlice (SMS) EPI capable of unaliasing 3 slices excited simultaneously with a modest g-factor penalty allowing us to diffusion encode whole brain volumes with low TR and TE. Finally we combine the multi-slice approach with a compressive sampling reconstruction to sufficiently undersample q-space to achieve a DSI scan in less than 5min. To augment this accelerated imaging approach we developed a 64-channel, tight-fitting brain array coil and show its performance benefit compared to a commercial 32-channel coil at all locations in the brain for these accelerated acquisitions.
The technical challenges of developing the over-all system are discussed as well as results from SNR comparisons, ODF metrics and fiber tracking comparisons. The ultra-high gradients yielded substantial and immediate gains in the sensitivity through reduction of TE and improved signal detection and increased efficiency of the DSI or HARDI acquisition, accuracy and resolution of diffusion tractography, as defined by identification of known structure and fiber crossing.
•Approach for advancing the sensitivity of the diffusion connectivity measurement.•Optimization of Gmax=300mT/m gradient, RF coil and sequence.•Improved sensitivity and diffusion contrast in high quality DSI/Q Ball.
Introduction
Suicidal thoughts are relatively common among college students in Iran. However, measures frequently used to assess suicidality or specific aspects of suicidal ideation in the United ...States have yet to be validated in Iran. Thus, the present study validated Farsi versions of the Depressive Symptom Inventory Suicidality Subscale (F‐DSI‐SS) and Suicide Rumination Scale (F‐SRS) among Iranian college students.
Methods
College students (N = 1043; 88.1% women) completed the F‐DSI‐SS. Forty‐six percent (n = 481) of participants reported the presence of suicidal thoughts and were eligible to fill out the F‐SRS. Analyses focused on validating the factor structure, construct, and convergent validity of the F‐DSI‐SS and F‐SRS among college students, as well as testing measurement invariance by gender of the F‐DSI‐SS.
Results
Confirmatory factor analysis (CFA) indicated that the F‐DSI‐SS and F‐SRS had good fit to the data and each displayed a one‐factor structure. Furthermore, the F‐DSI‐SS showed strong measurement invariance across genders. Internal consistency of the F‐DSI‐SS and F‐SRS was good. Lastly, the F‐DSI‐SS and F‐SRS's items and their total scores were intercorrelated and demonstrated good convergent validity.
Conclusion
Findings suggest that the F‐DSI‐SS and F‐SRS will enable researchers to examine suicidal thoughts and suicide‐specific rumination in Iran.
•A significant water storage loss of −158 ± 22 km3 occurred in August 2022 concerning July 2022 in the Yangtze River Basin.•The precipitation deficit and prolonged high temperature caused this ...extreme drought.•The hydrological drought identified by gravity satellite responds fast to meteorological drought.
In 2022, the Yangtze River Basin (YRB) experienced its most extreme drought event since 1961. Conducting a comprehensive assessment of this severe drought is crucial for understanding the entire drought process. GRACE and GRACE-FO gravity satellites have the capability to monitor global mass transport, making them suitable for large-scale drought monitoring. In this study, we investigated the changes in water storage caused by the drought using GRACE/GRACE-FO data and multi-source observations. Our evaluation incorporated meteorological drought indices, including the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), to explore the drought propagation process. Additionally, we examined the effects of trends in terrestrial water storage in the YRB, resulting from reservoir impoundment and climatic factors, on the drought index calculation. The results indicate that the extreme drought in the YRB began in August 2022, resulting in a water storage loss of approximately −158 ± 22 km3 compared to July 2022. There was almost no delay in the response of soil moisture drought and hydrological drought to the meteorological drought at a monthly scale. This extreme drought had its most severe impact on the middle and lower reaches of the YRB, especially in the Dongting Lake Basin, where the GRACE drought index value remained below −2.5 until December 2022. This study demonstrates the significant water storage deficit during the extreme drought in the YRB in 2022, providing a comprehensive understanding of this historic drought.
The Medium Energy X-ray telescope (ME) is one of the three main telescopes on board the
Insight
hard X-ray modulation telescope (
Insight-
HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN ...detectors sensitive in 5–30 keV with a total geometrical area of 952 cm
2
. The application specific integrated circuit (ASIC) chip, VA32TA6, is used to achieve low power consumption and low readout noise. The collimators define three kinds of field of views (FOVs) for the telescope, 1°×4°, 4°×4°, and blocked ones. Combination of such FOVs can be used to estimate the in-orbit X-ray and particle background components. The energy resolution of ME is ~3 keV at 17.8 keV (FWHM) and the time resolution is 255 μs. In this paper, we introduce the design and performance of ME.
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