Density Functional Theory Study on Anisotropic Arrangement of Interstitial Oxygen Atoms at (001) Interface of Oxide Precipitates in Si Crystal

The stability of the anisotropic oxygen (O) arrangement at the (001) interface of oxide precipitate (OP) in a Si crystal was analyzed by the density functional theory to understand the OP/Si interfacial structure and the gettering mechanism at the interface at an atomic level. In contrast to the case of the Si bulk, the O atoms align in one Si-Si zig-zag bond to some extent, then start to occupy other Si-Si bonds. After the O atoms are arranged in multiple series in the first interface layer to some extent, those in the second layer become more stable. This trend was confirmed for the second and third layers. The results support the existence of an experimentally observed transition layer with a composition of SiOx (x < 2) at the interface [Kissinger et al., ECS J. Solid State Sci. Technol., 9, 064002 (2020)]. Furthermore, several O alignments at the interface drastically reduce the formation energy of Si vacancies. The vacancies at the OP/Si interface were found to be effective gettering sites for Cu while the dangling bond was found to be an effective gettering site for Ni with a binding energy exceeding 1 eV.

Perspective on the true incidence of bowel perforations occurring with extreme lateral lumbar interbody fusions. How should they be treated?

Background: What is the risk of bowel perforation (BP) with open or minimally invasive (MI) extreme lateral lumbar interbody fusion (XLIF)? What is the truth? Further, if peritoneal symptoms/signs arise following XLIF/MI XLIF, it is critical to obtain an emergent consultation with general surgery who can diagnose and treat a potential BP. Literature Review: In multiple series, the frequency of BP ranged markedly from 0.03% (i.e. 1 of 2998 patients), to 0.08% (11/13,004), to 0.5%, to 8.3% (1 in 12 patients), up to 12.5% (1 in 8 patients). BPs attributed to different causes carry high mortality rates varying from 11.1% to 23%. For the 11 (0.08%) BP occurring out of 13,004 patients undergoing XLIF in one series, there was one (9.09%) death due to uncontrolled sepsis. In another series, where 31 BP were identified for multiple lumbar surgical procedures identified through PubMed (1960–2016), including 10 (32.2%) for lateral lumbar surgery including XLIF, the overall mortality rate was 12.9% (4/31). Conclusion: The incidence of BPs occurring following XLIF/MI XLIF procedures ranged from 0.03% to 12.5% in various reports. What is the true incidence of these errors? Certainly, it is more critical that when spine surgeons’ patients develop acute peritoneal symptoms/signs following these procedures, they immediately consult general surgery to both diagnose, and treat potential BP in a timely fashion to avoid the high morbidity (87.1%) and mortality rates (12.9%) attributed to these perforations.

Quantitative Characterization of Pore Space for the Occurrence of Continental Shale Oil in Lithofacies of Different Types: Middle Jurassic Lianggaoshan Formation in Southeastern Sichuan Basin of the Upper Yangtze Area

In addition to marine and marine-continental transitional strata, the continental ones are also widely distributed in various oil and gas-bearing basins in China. The continental shale generally provides favorable material bases for hydrocarbon generation, such as wide distribution, large thickness, multiple series of strata, high TOC content, nice organic matter type, and moderate thermal evolution. Part of such shale contains shale oil, but the pore space characteristics for the occurrence of this oil are not thoroughly studied. In order to accurately and quantitatively characterize the pore space where the continental shale oil in different types of lithofacies occurs, we sampled the rock cores from the Middle Jurassic Lianggaoshan Formation in the southeastern Sichuan Basin of the Upper Yangtze Area. The TOC content and mineral composition were analyzed, and we also carried out experiments on CO2 and N2 adsorptions, high-pressure mercury injection, and wash oil. Results show significant differences in pore space characteristics for the occurrence of shale oil in different types of lithofacies. In organic-rich mixed and clayey mudstones with the highest TOC content, the free shale oil, occupying the largest reservoir space, mainly occurs in macropores and mesopores, and the adsorbed shale oil, occupying the largest reservoir space, mainly occurs in mesopores. In the organic-bearing clayey mudstone, which has a higher TOC content, the free shale oil takes a larger reservoir space and mainly occurs in macropores, followed by mesopores, and the absorbed one, occupying a larger reservoir space, mostly occurs in micropores and then the mesopores. The organic-bearing mixed mudstone has a moderate TOC content, in which the free shale oil occupies a smaller reservoir space and primarily occurs in mesopores, followed by macropores, and the absorbed one, which takes a larger reservoir space, all occurs in mesopores. In the fine sandstone, the free shale oil occupies a smaller reservoir space and primarily occurs in mesopores, while the absorbed one occupies a smaller reservoir space and all occurs in mesopores.

Performance of brazilian university handball players in the vertical jump after maximum strength training

This study aimed to analyze the performance of the vertical jump with counter movement (CMJ), in university handball athletes, immediately after the maximum strength training in multiple series and after 10 and 15min of rest. Twelve male athletes participated, age 20.9±2.4 years old, height 1.78±0.05m and Body Mass Index (BMI) 28.74±8.1kg/m2. After the tests and retests of 1 repetition maximum (1RM) for the dominant and non-dominant sides, in the leg extension, the volunteers performed crossover after 48 hours of the training sessions. CMJ measurements were collected before and immediately after each training protocol and after 10 and 15min of rest. Passive recovery between sets was three minutes. The intervals between training protocols were at least 45min. There were no statistical differences for the CMJ between the moments pre-, post-training session, 10 and 15min of rest in the different protocols, but progressive increases in the CMJ variables were observed, extending up to the 15th minute of rest, in all training protocols when comparing the results of the means of the CMJ variables of the moments post-training session, 10 and 15min of rest with the averages of the variables from the pre-training session, being more evident in the alternate unilateral protocol, which, unlike the other protocols of the study, performed series with the two lower limbs. It was evidenced that the training protocols of short duration and with high dynamic efforts, previously performed, influenced the performance of the CMJ, favoring for the transient improvement of the explosive muscular strength of the athletes.

Assessing Point Forecast Bias Across Multiple Time Series: Measures and Visual Tools

Measuring bias is important as it helps identify flaws in quantitative forecasting methods or judgmental forecasts. It can, therefore, potentially help improve forecasts. Despite this, bias tends to be under represented in the literature: many studies focus solely on measuring accuracy. Methods for assessing bias in single series are relatively well known and well researched, but for datasets containing thousands of observations for multiple series, the methodology for measuring and reporting bias is less obvious. We compare alternative approaches against a number of criteria when rolling origin point forecasts are available for different forecasting methods and for multiple horizons over multiple series. We focus on relatively simple, yet interpretable and easy to implement metrics and visualization tools that are likely to be applicable in practice. To study the statistical properties of alternative measures we use theoretical concepts and simulation experiments based on artificial data with predetermined features. We describe the difference between mean and median bias, describe the connection between metrics for accuracy and bias, provide suitable bias measures depending on the loss function used to optimise forecasts, and suggest which measures for accuracy should be used to accompany bias indicators. We propose several new measures and provide our recommendations on how to evaluate forecast bias across multiple series. /// Note: This is the final version of the paper, which appeared in the International Journal of Statistics and Probability. The first draft of this paper was uploaded to Preprints.org on 11 May, 2021: https://doi.org/10.20944/preprints202105.0261.v1 /// Copyrights: This is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).

Measuring the Effect of Government Response on COVID-19 Pandemic: Empirical Evidence from Japan

The basic approach of this research is to use an estimated series of effective reproduction number Rt and multiple series of index from Oxford COVID-19 Government Response Tracker (OxCGRT) to measure the effect of Japanese government’s response on COVID-19 epidemic by running a time-varying regression with flexible least squares method. Then, we use estimated series of time-varying coefficients obtained from the previous step as proxy variables for the government response’s effect and run stepwise regressions with policy indicators of OxCGRT to identify which specific policy can mitigate the spreading of the COVID-19 epidemic in Japan. The main finding is that the response of Japanese government on COVID-19 epidemic is basically effective. However, the effect of Japanese government’ policy is gradually weakening. Under our identification scheme, we find that policies of quarantine and movement restrictions are still most effective, but policies of public health system do not show much effectiveness in the regression analysis. Another important empirical finding is that policies of economic support are effective in reducing the spread of COVID-19. Within the framework of empirical strategy proposed in this paper, the conclusion should be explained in the context of the socio-political and health situation in Japan, but the methodology is assumed to be applicable to other countries and regions in the analysis of government performance of response to COVID-19.

Assessing Point Forecast Bias Across Multiple Time Series: Measures and Visual Tools

Measuring bias is important as it helps identify flaws in quantitative forecasting methods or judgmental forecasts. It can, therefore, potentially help improve forecasts. Despite this, bias tends to be under-represented in the literature: many studies focus solely on measuring accuracy. Methods for assessing bias in single series are relatively well-known and well-researched, but for datasets containing thousands of observations for multiple series, the methodology for measuring and reporting bias is less obvious. We compare alternative approaches against a number of criteria when rolling-origin point forecasts are available for different forecasting methods and for multiple horizons over multiple series. We focus on relatively simple, yet interpretable and easy-to-implement metrics and visualization tools that are likely to be applicable in practice. To study the statistical properties of alternative measures we use theoretical concepts and simulation experiments based on artificial data with predetermined features. We describe the difference between mean and median bias, describe the connection between metrics for accuracy and bias, provide suitable bias measures depending on the loss function used to optimise forecasts, and suggest which measures for accuracy should be used to accompany bias indicators. We propose several new measures and provide our recommendations on how to evaluate forecast bias across multiple series.

Current Developments in Native Nanometric Discoidal Membrane Bilayer Formed by Amphipathic Polymers

Unlike cytosolic proteins, membrane proteins (MPs) are embedded within the plasma membrane and the lipid bilayer of intracellular organelles. MPs serve in various cellular processes and account for over 65% of the current drug targets. The development of membrane mimetic systems such as bicelles, short synthetic polymers or amphipols, and membrane scaffold proteins (MSP)-based nanodiscs has facilitated the accommodation of synthetic lipids to stabilize MPs, yet the preparation of these membrane mimetics remains detergent-dependent. Bio-inspired synthetic polymers present an invaluable tool for excision and liberation of superstructures of MPs and their surrounding annular lipid bilayer in the nanometric discoidal assemblies. In this article, we discuss the significance of self-assembling process in design of biomimetic systems, review development of multiple series of amphipathic polymers and the significance of these polymeric “belts” in biomedical research in particular in unraveling the structures, dynamics and functions of several high-value membrane protein targets.