INCIDENCE AND LETHALITY OF COVID-19 CLUSTERS IN BRAZIL VIA CIRCULAR SCAN METHOD

The COVID-19 pandemic has spread rapidly around the world in a frightening way. In Brazil, the third country with the highest number of infected and deaths from the disease, it is important for government health authorities to identify the federation units that stand out in cases and deaths from this disease to target resources. The circular scan statistic proposed by Martin Kulldorff allows to identify with some statistical significance the units of the federation that stand out in relation to the number of cases and deaths of COVID-19 in Brazil. Such units of federation are known as clusters. Once these clusters were identified, we used the coefficients of incidence and lethality to better describe the behavior of these clusters during three phases of the pandemic: the initial phase, the peak phase, and also the stability and fall phase. We observed changes in the location of the clusters identified in these three phases and used the R software and also the SaTScan software to obtain the maps and results, which were consistent with what was reported by the Brazilian media.

Observed of Equatorial Currents in the Indian Ocean during Two Contrasting IOD Events: 2006 and 2010

The evolution of Indian Ocean Dipole (IOD) events in 2006 and 2010 is investigated using observational data products that are made to understand several processes in the positive (negative) phase of IOD events. Two Acoustic Doppler Current Profiler (ADCP) moorings mounted at 90°E and 80.5°E along the equator were used to evaluate the zonal current variation during two contrasting Indian Ocean Dipole (IO) events. Westward anomalies of the zonal current were observed at 0°, 80.5°E during the peak phase of the positive IOD event from October to December 2006. Meanwhile, the observed zonal currents at 0°, 90°E only showed the short-term westward anomalies during October 2006. On the other hand, during the negative IOD event in 2010, the observed zonal current at both mooring locations indicated strong intraseasonal variations of the eastward anomalies from August to December 2010. Strong easterly (westerly) anomalies of the surface zonal winds were observed during the peak phase of the positive (negative) IOD event in 2006 (2010). These easterly (westerly) anomalies forced upwelling (downwelling) equatorial Kelvin waves indicated by the negative (positive) sea surface height anomalies. Strengthening (weakening) of upwelling (downwelling) along the equatorial Indian Ocean would be a significant factor for further understanding of IOD evolution.

Hospital Admissions for Neurodegenerative Diseases during the First Wave of the COVID-19 Pandemic: A Nationwide Cross-sectional Study from Germany

(1) Background: The COVID-19 pandemic impacts healthcare utilization across all care settings and health conditions. The objective of this study was to determine changes in hospital admissions for neurodegenerative diseases (NDD) during the first COVID-19 wave in Germany; (2) Methods: This cross-sectional study used nationwide administrative claims data covering 1468 hospitals. The primary outcome was the year-to-year relative change in case numbers during a four-month study period (16 January–15 May 2020 vs. 2019) during the first pandemic wave. Secondary outcomes included year-to-year relative changes during a four-week peak phase (16 March–15 April) and changes between differential phases of the wave. The analyzed NDD comprised progressive supranuclear palsy (PSP), multiple system atrophy (MSA), Parkinson’s disease, amyotrophic lateral sclerosis (ALS) and Huntington’s disease; (3) Results: Hospital admissions for any reason decreased by 16.7% in 2020 during the study period and by 36.6% during the peak phase, whereas admissions for NDD decreased by 27.6% and 65.0%, respectively. PSP cases decreased during the study period (−34.7%) and the peak phase (−68.1%) and stayed reduced in a late phase with falling COVID-19 numbers. MSA and ALS cases increased strongest after the peak, with ALS cases being comparatively weakly reduced during the study period (−17.3%) and peak phase (−51.7%); (4) Conclusions: Inpatient care utilization for NDD changed differentially during the first wave of the COVID-19 pandemic in Germany and showed a greater reduction than overall and general neurological admissions. Mitigating long-term health deterioration of this vulnerable subgroup is important to reduce morbidity and mortality in the future.

Prediksi spasio temporal rob berbasis model LISFLOOD FP di Pesisir Jakarta.

Abstrak Jakarta khususnya daerah pesisir sangat rentan dengan adanya permasalahan lingkungan berupa rob. Pemetaan daerah yang berpotensi terdampak rob sangat diperlukan guna menyusun upaya mitigasi. Pada penelitian ini dilakukan prediksi tinggi muka laut dengan model Delft3D dan digunakan untuk memprediksi daerah tergenang rob menggunakan model LISFLOOD FP pada tanggal 18 – 20 November 2019 di pesisir Jakarta. Hasil penelitian menunjukkan bahwa prediksi tinggi muka laut memiliki akurasi yang baik, dengan koefisien korelasi pada tingkat kuat sebesar 0,93 dan nilai RMSE sebesar 0,13 meter. Sementara itu, prediksi rob model LISFLOOD FP menunjukkan luas maksimum yang terjadi 2 hingga 3 jam setelah fase puncak tinggi muka laut dan menggenangi 8 kecamatan di Jakarta Utara dan Jakarta Barat. Abstract Jakarta region especially the coastal areas are very vulnerable to environmental problems such as coastal inundation. Mapping of areas potentially affected by coastal inundation is needed to arrange mitigation efforts. In this study, sea level prediction was estimated using the Delft3D model and used to predict coastal inundation areas using the LISFLOOD FP model on 18-20 November 2019 on the coast of Jakarta. The results showed that the sea-level prediction model has good accuracy, with a correlation coefficient at a strong level of 0.92 and an RMSE error value of 0.13 meters. Meanwhile, coastal inundation prediction from the LISFLOOD FP model inundated 8 sub-districts in North Jakarta and West Jakarta and showed the maximum area in 2 to 3 hours after the peak phase of sea level.

SPECIAL ASPECTS OF DEFORMATION OF COASTAL PROFILE DURING A FULL STORM CYCLE

Deformations of the coastal accumulative profile during a full storm cycle can be related both to the special aspects of individual storms and to seasonal cycles of wave activity. There is a concept of a “winter” and a “summer” type of coastal profile. The difference between these types of profiles is the isolation of the outer underwater berm in winter due to the transfer of sand material to depth and an increase of slopes in the surf zone in summer due to the transfer of sand material to the shore. In this case, the post-storm relief is determined by the character of the wave intensity reduction phase, i.e., the storm attenuation phase. The attenuation of the storm can be prolonged and accompanied by local peaks in wave heights, which will decrease gradually. In this case, the storm has a high potential for beach recovery and the underwater berm may shift toward the shore. In another case, storm attenuation can occur relatively quickly – the original profile is not recovered and at the end of the storm, the profile shape reflects the erosion in the peak phase. Relevant is the determination of the special features of the resulting deformations at the end of the storm cycle, in particular at the end of the storm attenuation phase. In this paper, the special features of storm deformations of the coastal sand profile, which were observed during field experiment on the Bulgarian coast and during monitoring observations on the Baltic Spit, are considered. In one case (the Bulgarian coast) it is a transition from the typical “summer” profile to the “winter” profile. In another case (Baltic Spit), a shift of the outer underwater berm toward the shore was revealed, which can be considered as a transition to the “summer” profile. It is revealed that the features of the storm attenuation stage in the two cases under consideration have specific differences. It is shown that transformations of the coastal profile, characterized as seasonal, can occur during the full cycle of a single storm event.

Performance Investigation of Switched Reluctance Motor Driven by Quasi-Z-Source Integrated Multiport Converter with Different Switching Algorithms

Switched reluctance machines (SRMs) have received increasing attention for their many potential uses, such as for wind power and electric vehicle (EV) drive systems. The Quasi-Z-source Integrated Multiport Converter (QZIMPC) was recently introduced to improve the reliability of the SRM driver through small capacitance values. It is not possible, however, to simultaneously energize and deenergize two SRM phases in QZIMPC. This phenomenon can significantly increase the commutation period which, in turn, degrades the performance of SRM; in addition, this causes high-voltage ripples on the converter’s capacitors. Two switching algorithms are introduced and applied in this paper, and their performance with SRM is investigated in terms of torque ripple and peak phase current. The algorithms are based on prioritizing the control command in the on-going and off-going phases to fulfill the required load torque, as well as to accelerate the commutation process where possible. This is achieved without the interference of high-level controllers, which include speed controllers and/or torque ripple minimization. Through the simulation results, a comparison between the two switching algorithms is presented to determine their potential to improve the SRM drive system’s performance.

Estimation and verification of fractional derivative-based permeability of coals considering mining-induced stresses

To overcome the inaccuracy of the traditional transient pulse test, a new fractional derivative-based permeability estimation formula based on the transient pulse test is proposed to describe the pressure difference decay of a coal body subjected to mining-induced stresses. The permeability of coal specimens under mining disturbance conditions is measured using the MTS815 rock mechanics test system. The experimental results show that the transient pulse test based on the fractional derivative model provides a much better estimation of the coal specimen’s permeability than the conventional exponential decay model. Analyzing the evolution of the coal’s permeability shows that the permeability tends to decrease in the pre-peak compaction stage, following which it gradually increases in the plastic phase, and then increases sharply in the post-peak phase. The significance of the fractional derivative order γ is discussed, and its analysis shows that the solid-liquid interaction inside the specimen becomes complicated when the stress within the coal specimen changes.

Severe COVID-19 in Uganda across Two Epidemic Phases: A Prospective Cohort Study

Among a prospective cohort of children and adults admitted to a national COVID-19 treatment unit in Uganda from March to December 2020, we characterized the epidemiology of and risk factors for severe illness. Across two epidemic phases differentiated by varying levels of community transmission, the proportion of patients admitted with WHO-defined severe COVID-19 ranged from 5% (7/146; 95% CI: 2–10) to 33% (41/124; 95% CI: 25–42); 21% (26/124; 95% CI: 14–29%) of patients admitted during the peak phase received oxygen therapy. Severe COVID-19 was associated with older age, male sex, and longer duration of illness before admission. Coinfection with HIV was not associated with illness severity; malaria or tuberculosis coinfection was rare. No patients died during admission. Despite low mortality, hospital incidence of severe COVID-19 during the first epidemic peak in Uganda was substantial. Improvements in vaccine deployment and acute care capacity, including oxygen delivery, are urgently needed to prevent and manage severe COVID-19 in sub-Saharan Africa.

Anxiety, PTSD, and stressors in medical students during the initial peak of the COVID-19 pandemic

Purpose To assess psychological effects of the initial peak phase of the COVID-19 pandemic on United States (US) medical students in clinical training to anticipate sequelae and prepare for future outbreaks. Methods Authors emailed a cross-sectional survey in April-May, 2020 to students in clinical training years at six US medical schools which included validated General Anxiety Disorder (GAD-7) and Primary Care-PTSD (PC-PTSD-5) screening tools, and asked students about pandemic-related stress and specific concerns. Authors used quantitative and thematic analysis to present results. Results Of 2511 eligible students, 741 responded (29.5%). Most students (84.1%) reported at least “somewhat” increased levels of stress and anxiety related to the pandemic. On the GAD-7, 34.3% showed mild, 16.1% moderate, and 9.5% severe anxiety symptoms, with 39.6% demonstrating no/minimal symptoms. One quarter (25.4%) screened positive for PTSD risk symptoms. Top concerns of students chosen from a pre-populated list included inadequate COVID-19 testing, undiagnosed or asymptomatic spread and racial or other disparities in the pandemic. In thematic analysis, students’ reactions to removal from clinical learning included: understanding the need to conserve PPE (32.2%), a desire to help (27.7%), worry over infectious risk to others (25.4%) and self (21.2%), and lost learning opportunities (22.5%). Female students were significantly more likely to report anxiety and PTSD risk symptoms. Asian students had a greater risk of moderate anxiety and those underrepresented in medicine (UIM) had greater risk of moderate and severe anxiety symptoms compared to white students. Conclusions During the initial peak phase of COVID-19, over 60% of US medical students screened positive for pandemic-related anxiety and one quarter were at risk for PTSD. Female and UIM students were significantly more affected. Medical schools should consider broad support of students, and targeted outreach to female and UIM students.

Experimental Study on the Transition Characteristics and Criterion From Wall-Peak to Core-Peak Phase Distribution in Vertical Rod Bundles

Aiming at understanding the phase distribution characteristics and developing the transition criterion from wall-peak to core-peak phase distribution in a rod bundle channel, air–water two-phase flow experiments were conducted in 5 × 5 rod bundles in the Interfacial Evolution Research Facility at Chongqing University (IERFC). Based on the experimental data, the influences of gas velocity, liquid velocity, mixing vane spacer grid (MVSG), and geometrical size on phase distribution have been analyzed in detail. With the increasing superficial gas velocity and decreasing liquid velocity, the wall-peak phase distribution turned to core-peak. The wall-peak phase distribution was enhanced by an MVSG, and the transition from the transitional phase distribution to the wall-peak phase distribution appeared when the air–water mixture flowed through the MVSG. The gap size was the key factor for the transition of phase distribution in rod bundles. Moreover, the transition criterion from wall-peak to core-peak phase distribution was developed based on present experimental data and the data in the literature, which was also verified based on the limited data. More experiments were recommended to focus on the detailed phase distribution in the rod bundle channel with different geometrical sizes.