Intensive care unit hospitalizations and outcomes in patients with severe COVID-19 during summer and fall surges in Georgia

BACKGROUND There is limited data on the difference in the clinical characteristics and outcomes of patients with severe coronavirus disease 2019(COVID-19)infection in the summer compared to the fall surge.AIM To compare the sociodemographic,clinical characteristics,and outcomes among mechanically ventilated patients with severe COVID-19 infection admitted to the intensive care unit(ICU)during the summer and fall surges in the year 2020.METHODS We included patients admitted to the ICU and treated with invasive mechanical ventilation for COVID-19 associated respiratory failure between April 1 and December 31,2020.Patients were categorized into summer surge for ICU admissions between June 15,2020,and August 15,2020,and fall surge between October 15,2020,and December 31,2020.We compared patients'characteristics and outcomes using descriptive and inferential statistics.RESULTS A total of 220 patients were admitted to the Grady Memorial Hospital ICU and mechanically ventilated for COVID-19 associated hypoxemic respiratory failure during the period considered(125 during the summer surge and 95 during the fall surge).More women were admitted in the fall compared to summer(41.1%vs 36.8%,difference,4.3%;95%CI:1.2,7.5).Patients admitted in the fall had fewer comorbidities(chronic obstructive pulmonary disease,stroke,diabetes mellitus,obstructive sleep apnea and body mass index≥35 kg/m2).Overall,patients in the fall had a lower ICU mortality rate(27.4%vs 38.4%,difference,-11.0;95%CI:-6.4,-18.2),shorter length of stay on the mechanical ventilator(7 d vs 11 d,difference,4 d;95% CI:2.1,6.6)and shorter ICU length of stay(9 d vs 14 d,difference,5 d;95% CI:2.7,9.4).CONCLUSION Patients admitted with severe COVID-19 infection requiring mechanical ventilation had better outcomes in the fall than summer.This difference observed is likely attributable to a better understanding of the condition and advances in treatment strategies.

Effects of straw mulching on microclimate characteristics and evapotranspiration of drip-irrigated winter wheat in North China Plain

Field experiments were conducted for two consecutive years(2013-2014 and 2014-2015)to study the effects of straw mulching on microclimate characteristics,energy flux,soil evaporation(Es)and evapotranspiration of winter wheat(Triticum aestivum L.)under adequate drip irrigation in North China Plain(NCP).The results revealed that straw mulching affected air temperature(T_(a))and dew point temperature(T_(d))near the soil surface but had little effect on relative humidity(RH)compared with non-mulched fields.Straw mulching increased the turbulent exchange coefficient(K),and K within the canopy was higher than that above the canopy.Straw mulching clearly increased the sensible heat flux(H)distribution in April-June,and part of the energy needed for evapotranspiration was provided by transfer from the warmer air aloft.There was a linear functional relationship between H and T_(a)measured above and within the canopy.The straw mulching decreased Es but increased crop transpiration(T).Mulched treatment(TM)can decrease the total irrigation amount by about 7%-15%compared with the non-mulched treatment(TN).There were no significant differences(p>0.05)in cumulative crop evapotranspiration(ETc)between TM and TN treatments under adequate drip irrigation,and the use of mulch may need to be combined with an optimal deficit drip irrigation schedule for managing the declining water table in NCP.

缩小规模:次国家的比较方法

对次国家单位的分析在比较政治学中起到了越来越重要的作用。虽然近来许多关于各种主题的研究——诸如伦理冲突、经济政策改革和民主化——都依赖于对不同的次国家政治单位之间的比较,但是对这些单位进行比较分析而产生的方法论问题还没有得到充分的关注。为了填补这一空白,本文探究了这一问题,即次国家的比较如何能够拓展和加强这些可供社会科学研究者利用的方法论内容。首先,因为对次国家单位的关注,对于增加观察数量以及进行可控性比较而言是一种重要的工具,所以这种关注也有助于缓解小样本(small-N)研究设计中的那些典型的局限。其次,对次国家单位的关注,增强了比较研究者将各种案例准确编码(code)并由此作出有效的因果推论的能力。最后,次国家的比较可以更好地使研究者把握政治与经济转型的主要进程在空间上的不均衡性。