[Changes of soil water budget in the area covered by biological soil crusts in Mu Us sandy land, China]. / æ¯›ä¹Œç´ æ²™åœ°ç”Ÿç‰©ç»“çš®è¦†ç›–åŒºåœŸå£¤æ°´åˆ†æ”¶æ”¯å˜åŒ–ç‰¹å¾.

Exploring and quantifying the impacts of biological soil crusts on soil hydrological processes and soil water budget in semi-arid ecosystems can provide a theoretical basis for vegetation restoration and reconstruction in deserts. Based on continuous observation of soil water content in different types of areas covered by biological soil crusts (e.g., algae, moss) and bare sand in the Mu Us sandy land during the growing season (May to October) from 2018 to 2020, we examined the effects of biological soil crusts on soil water budget at a depth of 0-40 cm. Results showed that algae and moss crusts significantly reduced soil water supplement below 40 cm by rainfall and increased soil water evaporation loss, compared with that under bare sand. In the relatively wet year (2018), the amount of soil water expenditure (seepage+evaporation) covered by bare sand and the various types of biological soil crusts was less than that of rainfall, resulting in net soil water income. In the relative dry years (2019 and 2020), the amount of soil water expenditure covered by dominant algae and moss crusts was higher than that of rainfall, causing net soil water deficit, but opposite for bare sand. Biological soil crusts led to the imbalance of soil water budget of 0-40 cm depth and even soil water deficit in relatively dry years, which may lead to the succession of plant communities to be dominated by shallow-rooted plants in this area.

Associations of growth from birth to puberty with glycemic indicators at ~17.5 years: Evidence from Hong Kong's "Children of 1997" birth cohort.

BACKGROUND: From an evolutionary biology perspective, where growth and reproduction trade-off against longevity, we assessed the associations of growth from birth to puberty by phase with later glycemic indicators and any differences by sex. METHODS: In the population-representative Hong Kong Chinese "Children of 1997" birth cohort (n = 8327), the relation of initial size (weight-for-age z score (WAZ) at birth, length/height-for-age z score (LAZ) at 3 months or body-mass-index-for-age z score (BAZ) at 3 months based on the World Health Organization growth standards/references) and growth at different phases (WAZ gains from 0 to 2 and 2 to 8 years, LAZ or BAZ gains from 3 months to 3 years, 3 to 8 years and 8 to 14 years) with fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) at ~17.5 years, was assessed using adjusted partial least squares regression. Additional analyses further considered growth in late and early infancy. RESULTS: This study included 3276 of the cohort participants. Higher WAZ gain from 2 to 8 years, LAZ and BAZ gains from 3 to 8 years were consistently associated with higher FPG, adjusted for maternal and infant characteristics, family history of diabetes and household income. Also, higher BAZ gain from 3 to 8 years was associated with higher HbA1c. These associations did not differ by sex. CONCLUSIONS: Our findings suggest different mechanisms could underlie the pathogenesis of glucose intolerance. Factors that drive specific growth at different phases need to be evaluated to better inform child growth management for long-term health outcomes.

Assessment of left ventricular systolic and diastolic abnormalities in patients with hypertrophic cardiomyopathy using real-time three-dimensional echocardiography and two-dimensional speckle tracking imaging.

BACKGROUND: Conventional echocardiography is not sensitive enough to assess left ventricular (LV) dysfunction in hypertrophic cardiomyopathy (HCM) patients. This research attempts to find a new ultrasonic technology to better assess LV diastolic function, systolic function, and myocardial longitudinal and circumferential systolic strain of segments with different thicknesses in HCM patients. METHODS: This study included 50 patients with HCM and 40 healthy subjects as controls. The peak early and late mitral annulus diastolic velocities at six loci (Ea' and Aa', respectively) and the Ea'/Aa' ratio were measured using real-time tri-plane echocardiography and quantitative tissue velocity imaging (RT-3PE-QTVI). The mean value of Ea' at six loci (Em') was obtained for the calculation of E/Em' ratio. The LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), LV stroke volume (LVSV), and LV ejection fraction (LVEF) were measured using real-time three-dimensional echocardiography (RT-3DE). LV myocardial longitudinal peak systolic strain (LPSS) and circumferential peak systolic strain (CPSS) in the apical-middle-basal segments (LPSS-api, LPSS-mid, LPSS-bas; CPSS-api, CPSS-mid, and CPSS-bas, respectively) were obtained using a software for two-dimensional speckle tracking imaging (2D-STI). According to the different segmental thicknesses (STs) in each HCM patient, the values (LPSS and CPSS) of all the myocardial segments were categorized into three groups and the respective averages were computed. RESULTS: The Ea', Aa', and, Ea'/Aa' ratio in HCM patients were lower than those in the controls (all p < 0.001), while the E/Em' ratio in HCM patients was higher than that in the controls (p < 0.001). The LVEDV, LVSV, and LVEF were significantly lower in HCM patients than in controls (all p < 0.001). In HCM patients, the LPSS-api, LPSS-mid, LPSS-bas, CPSS-api, CPSS-mid, and CPSS-bas and the LPSS and CPSS of LV segments with different thicknesses were all significantly reduced (all p < 0.001). CONCLUSIONS: In HCM patients, myocardial dysfunction was widespread not only in the obviously hypertrophic segments but also in the non-hypertrophic segments; the LV systolic and diastolic functions were damaged, even with a normal LVEF. LV diastolic dysfunction, systolic dysfunction, and myocardial deformation impairment in HCM patients can be sensitively revealed by RT-3PE-QTVI, RT-3DE, and 2D-STI.

What is the best lateral radiograph positioning technique for assessment of sagittal balance: A biomechanical study on influence of different arm positions.

PURPOSE: To evaluate the influence of different arm postures from the physiological standing position using force plate analysis of the gravity line. METHODS: Forty healthy volunteered university students were enrolled. Each subject assumed different standing positions including standing with arms resting on the side (control), with fist over the clavicle (clavicular position), with active shoulder flexion in 30°, 60° and 90° with elbows extended (active flexion A), with hand rest on a bar with a static support (passive flexion P), and with hand rest on a bar with a drip stand (passive flexion D). The offset of the gravity line from the heel was measured by force plate analysis. The offset of the gravity line in different arm positions was compared with the control using paired t-test. RESULTS: The mean anterior offset of the gravity line in control position is 39.80% of the foot length. All testing positions showed anterior shift of the gravity line compared with the control position from 0.51% to 7.50%. There were statistically significant changes of the gravity line from the control position in all ( p < 0.05), except in the clavicular position ( p = 0.249). CONCLUSION: All testing positions cause anterior shifting of the center of gravity from the physiological standing position. Clavicular position is the best comparable posture to the physiological standing position in taking a lateral radiograph. We recommend using the clavicular position as the standard testing position in the assessment of the sagittal profile.