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Objective: This study investigates the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission potential in North Dakota, South Dakota, Montana, Wyoming, and Idaho from March 2020 through January 2021. Methods: Time-varying reproduction numbers, R t , of a 7-d-sliding-window and of non-overlapping-windows between policy changes were estimated using the instantaneous reproduction number method. Linear regression was performed to evaluate if per-capita cumulative case-count varied across counties with different population size or density. Results: The median 7-d-sliding-window R t estimates across the studied region varied between 1 and 1.25 during September through November 2020. Between November 13 and 18, R t was reduced by 14.71% (95% credible interval, CrI, [14.41%, 14.99%]) in North Dakota following a mask mandate; Idaho saw a 1.93% (95% CrI [1.87%, 1.99%]) reduction and Montana saw a 9.63% (95% CrI [9.26%, 9.98%]) reduction following the tightening of restrictions. High-population and high-density counties had higher per-capita cumulative case-count in North Dakota on June 30, August 31, October 31, and December 31, 2020. In Idaho, North Dakota, South Dakota, and Wyoming, there were positive correlations between population size and per-capita weekly incident case-count, adjusted for calendar time and social vulnerability index variables. Conclusions: R t decreased after mask mandate during the region’s case-count spike suggested reduction in SARS-CoV-2 transmission.

Introduction: We aimed to examine how public health policies influenced the dynamics of coronavirus disease 2019 (COVID-19) time-varying reproductive number (R t ) in South Carolina from February 26, 2020, to January 1, 2021. Methods: COVID-19 case series (March 6, 2020, to January 10, 2021) were shifted by 9 d to approximate the infection date. We analyzed the effects of state and county policies on R t using EpiEstim. We performed linear regression to evaluate if per-capita cumulative case count varies across counties with different population size. Results: R t shifted from 2-3 in March to R t rose over the summer and stayed between 1.4 and 0.7. The introduction of statewide mask mandates was associated with a decline in R t (−15.3%; 95% CrI, −13.6%, −16.8%), and school re-opening, an increase by 12.3% (95% CrI, 10.1%, 14.4%). Less densely populated counties had higher attack rates (P < 0.0001). Conclusions: The R t dynamics over time indicated that public health interventions substantially slowed COVID-19 transmission in South Carolina, while their relaxation may have promoted further transmission. Policies encouraging people to stay home, such as closing nonessential businesses, were associated with R t reduction, while policies that encouraged more movement, such as re-opening schools, were associated with R t increase.

Objective:This study aimed to investigate coronavirus disease (COVID-19) epidemiology in Alberta, British Columbia, and Ontario, Canada.Methods:Using data through December 1, 2020, we estimated time-varying reproduction number, Rt, using EpiEstim package in R, and calculated incidence rate ratios (IRR) across the 3 provinces.Results:In Ontario, 76% (92 745/121 745) of cases were in Toronto, Peel, York, Ottawa, and Durham; in Alberta, 82% (49 878/61 169) in Calgary and Edmonton; in British Columbia, 90% (31 142/34 699) in Fraser and Vancouver Coastal. Across 3 provinces, Rt dropped to ≤ 1 after April. In Ontario, Rt would remain < 1 in April if congregate-setting-associated cases were excluded. Over summer, Rt maintained < 1 in Ontario, ~1 in British Columbia, and ~1 in Alberta, except early July when Rt was > 1. In all 3 provinces, Rt was > 1, reflecting surges in case count from September through November. Compared with British Columbia (684.2 cases per 100 000), Alberta (IRR = 2.0; 1399.3 cases per 100 000) and Ontario (IRR = 1.2; 835.8 cases per 100 000) had a higher cumulative case count per 100 000 population.Conclusions:Alberta and Ontario had a higher incidence rate than British Columbia, but Rt trajectories were similar across all 3 provinces.

Older trees in good health are expected to provide more ecosystem services and equivalent economic values due to their large size. The relationship of tree dimensions, respective tree height, crown area, diameter at breast height (dbh), and total leaf area vis-a-vis age were studied for 790 heritage trees ≥ 100 years old in Macau; 50 genera and 63 species were represented. Seven out of ten common genera showed no significant increase for all tested parameters except increase of dbh with age. Other factors, such as condition and geometry of growing spaces, controlled the performance of heritage trees, as well as the realization of their biological potential size, with implications on the provision of ecosystem services. The effects of these heritage trees on air-quality improvement and gross carbon sequestration were quantified by the i-Tree Eco model. Overall, 806.8 kg of air pollutants were removed annually, with benefits valued at US $8,091. The heritage trees stored 3,041 t carbon in total and sequestered 842 kg carbon/yr, equivalent to US $601 in annual benefits. The values were much higher than ordinary urban forest trees. Ten common heritage tree genera were ranked by their capacities for air quality improvement, carbon storage, and sequestration. The findings can serve as a decision tool for heritage tree management and conservation and to estimate potential ecosystem services of established trees

ObjectiveThis study investigates how the SARS-CoV-2 transmission potential varied in North Dakota, South Dakota, Montana, Wyoming, and Idaho from March 2020 through January 2021.MethodsTime-varying reproduction numbers,Rt, of a 7-day-sliding-window and of non-overlapping-windows between policy changes were estimated utilizing the instantaneous reproduction number method. Linear regression was performed to evaluate if per-capita cumulative case-count varied across counties with different population size.ResultsThe median 7-day-sliding-windowRtestimates across the studied region varied between 1 and 1.25 during September through November 2020. Between November 13 and 18,Rtwas reduced by 14.71% (95% credible interval, CrI, [14.41%, 14.99%]) in North Dakota following a mask mandate; Idaho saw a 1.93% (95% CrI [1.87%, 1.99%]) reduction and Montana saw a 9.63% (95% CrI [9.26%, 9.98%]) reduction following the tightening of restrictions. High-population counties had higher per-capita cumulative case-count in North Dakota at four time points (June 30, August 31, October 31, and December 31, 2020). In Idaho, North Dakota, and South Dakota, there was a positive correlation between population size and per-capita weekly incident case-count, adjusted for calendar time and social vulnerability index variables.ConclusionsRtdecreased after mask mandate during the region’s case-count spike suggested reduction in SARS-CoV-2 transmission.

In China, heritage trees are actively surveyed and reported. Over 300 relevant published articles were reviewed to assess the contents, trends and geographical distributions of the investigations. The majority of the heritage trees studies in China were found in the eastern provinces and published within 2010–2014. Most studies reported surveys on all old trees. For studies focused on single species, Ginkgo (Ginkgo biloba) and Chinese Yew (Taxus chinensis) was most frequently reported. Unlike the champion tree registry in the US and other countries, the tree registry in China emphasized more on the tree age than the size. We then have studied the heritage trees in the rapidly-developed municipality of Shenzhen in South China in details. The species composition, diversity and spatial distribution were investigated using ecological indices and statistical techniques. Most trees were native with domination by Ficus microcarpa. Heritage-tree density was not correlated with land area, population density, green cover, or district development year. The oldest and youngest districts have relatively higher species diversity and tree density. It indicated the preservation of an old town plan and the creation of a new town plan conducive to accommodating pre-urbanization heritage trees. Village and forest habitats with rich tree endowments can be targeted for conservation in new urban areas. The importance of adopting a nature-friendly town plan, and the associated policies that can facilitate it, are instrumental in heritage-tree nurturing and protection. The findings can inform tree preservation and urban green infrastructure provision in fast developing cities in China and beyond.

To describe the geographical heterogeneity of COVID-19 across prefectures in mainland China, we estimated doubling times from daily time series of the cumulative case count between 24 January and 24 February 2020. We analyzed the prefecture-level COVID-19 case burden using linear regression models and used the local Moran’s I to test for spatial autocorrelation and clustering. Four hundred prefectures (~98% population) had at least one COVID-19 case and 39 prefectures had zero cases by 24 February 2020. Excluding Wuhan and those prefectures where there was only one case or none, 76 (17.3% of 439) prefectures had an arithmetic mean of the epidemic doubling time &lt, 2 d. Low-population prefectures had a higher per capita cumulative incidence than high-population prefectures during the study period. An increase in population size was associated with a very small reduction in the mean doubling time (−0.012, 95% CI, −0.017, −0.006) where the cumulative case count doubled ≥3 times. Spatial analysis revealed high case count clusters in Hubei and Heilongjiang and fast epidemic growth in several metropolitan areas by mid-February 2020. Prefectures in Hubei and neighboring provinces and several metropolitan areas in coastal and northeastern China experienced rapid growth with cumulative case count doubling multiple times with a small mean doubling time.

ObjectiveTo investigate COVID-19 epidemiology in Alberta, British Columbia and Ontario, Canada.MethodsWe calculated the incidence rate ratio (January 1—July 6, 2020) between the 3 provinces, and estimated time-varying reproduction number, Rt, starting from March 1, using EpiEstim package in R.ResultsUsing British Columbia as a reference, the incidence rate ratios in Alberta and Ontario are 3.1 and 4.3 among females, and 3.4 and 4.0 among males. In Ontario, Rt fluctuated ~1 in March, reached values >1 in early and mid-April, then dropped Rt rose to ~1 in mid-May and then remained Rt dropped Rt Rt > 1 in March; Rt dropped in early April and rose again in late April. In much of May, Rt Rt increases in early June and fluctuates ~1 since mid-June.ConclusionsRt wavering around 1.0 indicated that three provinces of Canada have managed to achieve limited onward transmission of SARS-CoV-2 as of early July 2020.

COVID-19 epidemic doubling time by Chinese province was increasing from January 20 through February 9, 2020. The harmonic mean of the arithmetic mean doubling time estimates ranged from 1.4 (Hunan, 95% CI, 1.2-2.0) to 3.1 (Xinjiang, 95% CI, 2.1-4.8), with an estimate of 2.5 days (95% CI, 2.4-2.6) for Hubei.

The world’s fast pace of urbanization has exerted profound pressure on urban trees. With over 400 years of urban history, Macau has developed an exceptionally high population density and ultra-compact mode, yet it permits survival of interesting and diverse heritage trees. These outstanding living remnants connote special values in history, ecology and botany. In conjunction with commemorative importance, they have been designated as Old and Precious Trees (OPT). This study evaluated the OPT with reference to: (a) species diversity and evenness; (b) spatial distribution; (c) tree dimensions, age and health; and (d) spatial differentiation of tree attributes by four districts and eight tree-habitats. Heritage trees in Macau were compared with those in Hong Kong and Guangzhou. The 793 OPT belong to 63 species. The exotic Ficus rumphii is overwhelmingly dominant, followed by F. microcarpa , Cinnamomum camphora and Dimocarpus longan . Species composition, age distribution and health conditions are associated with tree-habitat. Roadside has the largest number of OPT but the least species richness. Public parks and gardens has the highest diversity and largest tree dimensions. The oldest trees are clustered in urban parks and religious places. Tree health is poorer at roadsides, and private residential and commercial properties. The patterns suggest close relationship between tree traits and physical fabric of the city. However, the variety rather than duration of geographical contacts is a key determinant of urban tree diversity. The findings offer insights for heritage-tree conservation and management strategies in compact cities with similar urban structure and history.

Pd-coated Cu wires show interesting properties such as good electrical conductivity, thermal conductivity, and reliability and are widely used in microelectronic packaging. However, during the formation of free air balls (FABs) and bonded balls via Pd-coated Cu wires, the electronic flame off (EFO) current setting affects Pd distribution in FABs and bonded balls. This study investigated the effect of different EFO current settings on Pd distribution during the formation of FABs and bonded balls, and also analyzed the influence of EFO current settings on FAB formation. Pd distribution in FABs and bonded balls, as well as the distribution of other elements, were observed. The corrosion on the surface of a bonded ball was observed through high temperature storage tests (HTSTs). The result revealed that there were different Pd distributions in the formation processed via different EFO current settings of FABs and bonded balls. Further, different EFO current settings also resulted in a different FAB shape. The result of HTST indicated that proportional Pd distribution could decelerate the corrosion of a bonded ball.

This study evaluated the effects of plant traits and substrate moisture on the thermal performance of four herbs and four shrubs, which are the most commonly used species in vertical greenery systems (VGSs), in humid subtropical Hong Kong over a one-year period. The canopy temperature reduction on sunny days was significantly correlated with canopy coverage and leaf area index (LAI), but not with daily evapotranspiration (ET). This indicated that the shading effect of VGSs, which is related to canopy coverage and LAI, was more prominent than ET cooling. The lack of significant correlation between substrate moisture, ET and canopy temperature indicated that substrate moisture and ET did not significantly enhance the canopy cooling of VGSs. Substrate moisture notably cooled the substrate on sunny days, and warmed the substrate on rainy days, which significantly affected substrate thermal behavior, but had less effect on canopy air temperature. The use of VGSs with eight common plant species on building envelopes reduced steady-state heat conduction by 18.7–39.8%, with Ficus elastica (rubber fig) causing the greatest canopy cooling.

Rehabilitation robot is usefully to improves walking ability on patients with gait disorders. Over the last decade, rehabilitation robot device replaced the training of overground and treadmill. The purpose of this study was to compare the differences in muscles activities of simulated human leg while walking on two gait rehabilitation robots: the exoskeleton rehabilitation robot and the end-effector rehabilitation robot. We have built models of simulated human leg, exoskeleton rehabilitation robot and end-effector rehabilitation robot. The results showed that rectus femoris and tibialis anterior muscles of the simulated human leg were more active while walking on the exoskeleton rehabilitation robot. The results of this study may provide technical improvement for gait rehabilitation robots, so that lower limb muscles movement can be more correctly achieved for normal individuals during gait rehabilitation training.

Rehabilitation robot positively improves walking ability of patients with gait disorders. Over the last decade, rehabilitation robot devices replaced the training of overground and treadmill. In this paper, our discussion focuses on exoskeleton robot and end-effector robot. The purpose of this study was to compare the training methods, gait Kinematic trajectories and muscle activity patterns on subjects when training on exoskeleton robot and end-effector robot.