Alternative Class Research Articles

NEARLY EFFICIENT LIKELIHOOD RATIO TESTS OF A UNIT ROOT IN AN AUTOREGRESSIVE MODEL OF ARBITRARY ORDER

We study large sample properties of likelihood ratio tests of the unit-root hypothesis in an autoregressive model of arbitrary order. Earlier research on this testing problem has developed likelihood ratio tests in the autoregressive model of order 1, but resorted to a plug-in approach when dealing with higher-order models. In contrast, we consider the full model and derive the relevant large sample properties of likelihood ratio tests under a local-to-unity asymptotic framework. As in the simpler model, we show that the full likelihood ratio tests are nearly efficient, in the sense that their asymptotic local power functions are virtually indistinguishable from the Gaussian power envelopes. Extensions to sieve-type approximations and different classes of alternatives are also considered.

Physical fitness changes in adolescents due to social distancing during the coronavirus disease pandemic in Korea.

At least 60 min of moderate-intensity physical activity per day is recommended for physical and mental health of adolescents. Schools are one of the most suitable places for promoting students' health as it is a place where vigorous physical activity occurs. However, the physical activity of students is threatened because schools are closed worldwide owing to the coronavirus disease (COVID-19) outbreak in 2019. Therefore, this study aimed to analyze the physical fitness changes in 27,782 Korean adolescents during the pandemic and present alternative education and health policies to the school. We included 29,882 middle school students (age: 13-15 years; males: 14,941, females: 12,841) in Korea from 2019 to 2021 . Participants' physical fitness at school was measured using the physical activity promotion system (PAPS) manual developed to measure students' physical fitness. Physical fitness variables included body mass index (BMI), 20 m shuttle run, handgrip strength, sit-and-reach, and 50 m run. The COVID-19 pandemic has had a negative impact on the BMI and cardiorespiratory endurance of Korean middle school students. Specifically, male students' BMI increased, while body composition, cardiorespiratory endurance, and grip strength decreased significantly. Female students showed significant decreases in BMI and sit-and-reach test scores. It is clear that the physical fitness level of adolescents decreased by a greater degree after the COVID-19 pandemic than before, and the decrease in the physical fitness level of male students was noticeable. Therefore, a lesson strategy should be prepared that considers the contents and methods of physical education classes to improve the physical fitness level of male and female adolescents. Fitness-based classes suitable for online methods should be urgently added as alternative physical education classes to prepare for the second COVID-19 outbreak. In addition, it is necessary to create an environment in which physical activity is a possibility in physical education classes, in any situation using artificial intelligence and virtual reality.

Is bitcoin a diversifier, hedge or safe haven for traditional and alternate asset classes?

Given the skyrocketing returns earned by bitcoin, it has received widespread attention as an investment asset. The shocks experienced by stock and bond markets over time and especially during the COVID-19 pandemic has led to an evaluation of bitcoin as a wealth protection asset, a role that gold has played until now. The current paper tests the hedging and safe haven properties of bitcoin in a broad portfolio of both developed and emerging markets stocks, bonds and real estate over a period of 10 years and during COVID-19 pandemic. Using a DCC-GARCH method, the study finds weak hedge and safe haven benefits of bitcoin. The results of the study establish that there is still a long way to go before bitcoin displays a strong safe haven behavior. However, there is a need for portfolio managers to become more cognizant about bitcoin given its potential to protect their portfolios.

Early onset tardive syndromes associated with Lurasidone in patients with mood disorders: A case series and literature review

• The incidence of tardive syndromes on antipsychotics is cumulative and screening as early as one month may enhance the opportunity for early detection and treatment. This is especially important in patients with mood disorders who can be managed using alternative drug classes and can achieve early and full resolution of the movement disorder without the need for antidyskinetic medications. • Differentiation of tardive dyskinesia from tardive dystonia and tardive akathisia is important as they may have different prognoses and treatment. This can be achieved both by expert clinical assessment and the use of scales that capture nuances in tardive syndromes • Newer antipsychotics such as lurasidone are increasingly used in mood disorders with good efficacy but there is limited data on the risks of tardive syndromes in this population. Further work is necessary to characterize which factors are most associated with early onset tardive syndromes. Tardive syndromes (TS) are a group of movement disorders that typically occur following chronic exposure to Dopamine D2 receptor antagonists. Rarely, these syndromes may occur in less than six months following the initiation of a causative medication. Owing to Lurasidone's recent introduction to the North American market, there is limited literature on its association with tardive syndromes. We describe three cases with mood disorder prospectively and systematically followed for tardive syndromes on Lurasidone and present a literature review of existing data on tardive syndromes associated with Lurasidone in patients with mood disorders. These three cases all developed TS before three months. A single previously published case series included cases of early-onset tardive syndromes following lurasidone use. This is an open case series in a single academic practice focused on mood disorders. There is limited data in the literature for comparison. Lurasidone's common use in patients with vulnerabilities to developing tardive syndromes, such as those with mood disorders, may be an area for clinical concern. Clinicians should strongly consider earlier screening for tardive syndromes in patients with appropriate risk factors.

내용중심 교수법을 적용한 유학생 교양교육 연구

Objectives The purpose of this study is to propose an whole model of liberal arts education based on content- based language instruction for international students, and furthermore, to present and share specific educational plans through actual cases. This was sought as one of the ways to solve the problems of the current international student education.
 Methods the literature research method was applied to understand the current status and problems of international student education and to confirm the necessity of the content-based language education. Subsequently, a case study was conducted on the class of ‘Understanding Korean Modern History’ which has been appling the adjunct model for years, and based on this, we extracted the effective class composition and scaffoldings for international student education.
 Results In order to compensate for the problems of the current international student education, this study presented a foreign student liberal arts class model that applied the content-based instruction step by step. In particular, it was confirmed through related cases that the adjunct model can be an alternative class form for early-stage international students.
 Conclusions Liberal education for international students should be conducted in the direction of enhancing Korean language and the ability to adapt to Korean universities and complete their studies along with content education. And for this, it is necessary to utilize a model that applies content-based language education. In particular, the adjunct model is suitable as a customized teaching method for international students before entering a full-fledged major class.

ABCG2 Polymorphisms and Predictive Fluoroquinolone Phototoxicity in Nondomestic Felids

Fluoroquinolones are a widely used class of chemotherapeutics within veterinary medicine, prized for their broad-spectrum bactericidal activity. These drugs present a known risk of retinal phototoxicity in domestic cats (Felis catus); therefore, using lower doses and alternative antibiotic classes is encouraged in this species. This adverse drug effect of fluoroquinolones, and enrofloxacin specifically, has been determined to be species-specific in domestic felids. Four feline-specific missense variants in ABCG2 result in four amino acid changes (E159M, S279L, H283Q, and T644I) that are unique to the domestic cat compared with multiple other nonfeline mammalian species. These changes alter the ABCG2 protein involved with the cellular transmembrane transport of drugs, including fluoroquinolones, making the protein functionally defective in domestic cats. The predisposition to fluoroquinolone-mediated phototoxicity in nondomestic felids was explored in this study. At least eight nondomestic felids share the four ABCG2 missense variants with domestic cats, and eleven other felids shared at least three of the four domestic cat variants. Taken together, these results suggest the genetic potential for nondomestic felids to also experience fluoroquinolone-induced retinal phototoxicity; therefore, cautions similar to those for domestic cats should be followed for these drugs in the entire feline taxon.

Stochastic simulation algorithm for isotope-based dynamic flux analysis

Carbon isotope labeling method is a standard metabolic engineering tool for flux quantification in living cells. To cope with the high dimensionality of isotope labeling systems, diverse algorithms have been developed to reduce the number of variables or operations in metabolic flux analysis (MFA), but lacks generalizability to non-stationary metabolic conditions. In this study, we present a stochastic simulation algorithm (SSA) derived from the chemical master equation of the isotope labeling system. This algorithm allows to compute the time evolution of isotopomer concentrations in non-stationary conditions, with the valuable property that computational time does not scale with the number of isotopomers. The efficiency and limitations of the algorithm is benchmarked for the forward and inverse problems of 13C-DMFA in the pentose phosphate pathways, and is compared with EMU-based methods for NMFA and MFA including the central carbon metabolism. Overall, SSA constitutes an alternative class to deterministic approaches for metabolic flux analysis that is well adapted to comprehensive dataset including parallel labeling experiments, and whose limitations associated to the sampling size can be overcome by using Monte Carlo sampling approaches.

Open Marxism, social class, and social and political movements

Open Marxists argue that capitalist society is mediated through forms of alienated and dispossessed labour from the means of production. For Open Marxists, then, labour is fluid in its constitution because it is constantly struggling to various degrees in and against its alienated and dispossessed capitalist form. Static sociological concepts of social class therefore cannot fully grasp this fluid and antagonistic relationship between labour and capital. In this paper, we agree that the starting point for an analysis of class under capitalism is the dispossession of labour from its means of production. But we further argue that even at this relatively high level of theoretical analysis, it is still possible to isolate a more complex account of social class than many Open Marxists would accept. We then employ this alternative class perspective to highlight some weaknesses in respective Open Marxist accounts of class and social and political movements. Following these critical observations, and with the theoretical assistance of Gramscian analysis, we demonstrate how Open Marxism can develop a more robust account of the class nature of contemporary social and political movements.

Empirical‐process‐based specification tests for diffusion models

AbstractWe develop two joint tests for the parametric drift and volatility functions of a diffusion model based on empirical processes. One key feature of our joint tests is that they account for different convergence rates of parameter estimators. The tests are of classical Kolmogorov–Smirnov and Cramér–von Mises types, and are asymptotically distribution free. The proposed tests have nontrivial power against a class of local alternatives with different convergence rates for the drift and volatility terms. Monte Carlo simulations show that the tests perform quite well in finite samples and outperform the nonparametric test of Hong and Li. The new tests are applied to EUR/USD exchange rate data and generate some interesting empirical findings that are consistent with our theoretical results and simulation studies.

학교 내 대안교실의 운영 성과분석

Objectives In this study, as part of the school interruption prevention policy, the operation status and performance of alternative classes in schools, which have been implemented since 2013, were analyzed and future improvement measures were presented. Methods To this end, first, a system model-based logic model was derived to evaluate the performance of the project, second, the status and status of alternative classes in schools of Gangwon-do Office of Education in 2018-2022, and third, based on the performance analysis model, a survey (32 school managers, 40 teachers) and an interview survey (7 teachers, 5 students). Results As a result of the analysis, more than 50% of the students who participated in the alternative class returned to school, and less than 10% of the students stopped studying, and most of the students did not stop or give up and were emotionally satisfied. Conclusions In addition to improving the perception of school members, it was found that the ultimate operation goal of alternative classes, “the ratio of school maladjusted students to stop studying,” was improved based on student satisfaction and attitude changes. However, as it can be seen that more than 50% of schools have stopped operating their businesses after a year since the first participation in the school, it was confirmed that policy improvement is needed in the direction of continuous management and operation of alternative classes in the school.

Di(2-picolyl)amines as Modular and Robust Ligands for Nickel-Catalyzed C(sp2)-C(sp3) Cross-Electrophile Coupling.

Ni-catalyzed aryl-alkyl coupling reactions are reliant on using a limited set of commercially available bidentate nitrogenous ligands to enable the reaction, because noncommercial analogues usually entail challenging syntheses. In this work, di(2-picolyl)amines (DPAs) are explored as an alternative modular ligand class for the nickel-catalyzed aryl-alkyl cross-electrophile coupling. Novel DPA ligands were synthesized directly from inexpensive amine and pyridine building blocks in a single step. This facile synthetic route enabled the parallel synthesis of DPA ligands with varied steric and electronic properties. From this collection of ligands, a few robust ligands for C(sp2)-C(sp3) cross-electrophile coupling were identified and tested in the cross-coupling of a range of diverse molecules, including model examples for late-stage functionalization.

Joint parametric specification checking of conditional mean and volatility in time series models with martingale difference innovations

Using cumulative residual processes, we introduce powerful joint specification tests for conditional mean and variance functions in the context of nonlinear time series with martingale difference innovations. The main challenge comes from the fact that, the cumulative residual process no longer admits a distribution-free limit. To obtain a practical solution one either transforms the process to achieve a distribution-free limit or approximates the non-distribution free limit using numerical or re-sampling techniques. In this paper, the three solutions are considered and compared. The proposed tests have nontrivial power against a class of root-n local alternatives and are suitable when the conditioning set is infinite-dimensional, which allows including more general models such as ARMAX-GARCH with dependent innovations. Numerical results based on simulated and real data show that the powers of tests based on re-sampling or numerical approximation are in general slightly better than those based on martingale transformation.

Glycolytic flux control by drugging phosphoglycolate phosphatase

Targeting the intrinsic metabolism of immune or tumor cells is a therapeutic strategy in autoimmunity, chronic inflammation or cancer. Metabolite repair enzymes may represent an alternative target class for selective metabolic inhibition, but pharmacological tools to test this concept are needed. Here, we demonstrate that phosphoglycolate phosphatase (PGP), a prototypical metabolite repair enzyme in glycolysis, is a pharmacologically actionable target. Using a combination of small molecule screening, protein crystallography, molecular dynamics simulations and NMR metabolomics, we discover and analyze a compound (CP1) that inhibits PGP with high selectivity and submicromolar potency. CP1 locks the phosphatase in a catalytically inactive conformation, dampens glycolytic flux, and phenocopies effects of cellular PGP-deficiency. This study provides key insights into effective and precise PGP targeting, at the same time validating an allosteric approach to control glycolysis that could advance discoveries of innovative therapeutic candidates.

Quality Teaching, Learning Language and Technology in Didactic Practice on the Time of Pandemic

It is in the dynamics of a world out of step, sometimes disoriented, strongly impacted by the Covid19 Coronavirus pandemic in particular, the 21 st century presents itself as a new world exposing a new geo-political map: the world is moving, changing vertiginously at an incredible speed ! Then, the prerogatives of education presupposed in traditional pedagogy have been called into question by new didactic prerogatives. And it is indeed in this pandemic context that researchers, linguists, and educational specialists are reflecting on the dizzying development of digital technology by innovating new approaches that are becoming the backbone of the educational challenge because learning is variable over time. In this international conference, as an invited speaker, we ask the main following question : to what extent does our study fit in with current pedagogical and technological innovation ? So we define the concept of quality in the context of educational sciences and its relationship between language learning (French /English) and technology. Computer sciences (the tool of ICT, distance learning) are an asset to Faerber (2002) Model of “pedagogical tetrahedron’. This is why quality assessment procedures for language learning (acquisition, cognitive training and distance learning) are essential. However, Our study is structured in three ways : firstly, it defines three concepts : the quality of teaching, language learning (French/English) and distance learning, secondly, the author examines two groups of students at two different levels, belonging to the alternative class and having taken distance education courses. Finally, the author arrives at the results by evaluating distance learning thanks to information technology, which brings a new way of thinking.

Risk hedging properties of infrastructure: a quantile regression approach

PurposeThis paper aims to examine the hedge, diversifier and safe haven properties of the global listed infrastructure sector and subsector indices against two traditional asset classes, stocks and bonds, and four alternative asset classes, including commodities, real estate, private equity and hedge funds during extreme negative stock market movements.Design/methodology/approachUsing dynamic conditional correlation and quantile regression, the authors analyze a data set of 12 indices comprising listed infrastructure and traditional asset classes from 2010 to 2019.FindingsOverall, the findings indicate that listed infrastructure acts as an effective diversifier but not as a strong safe haven or hedge when considered in a multiasset context. With minor exceptions, listed infrastructure cannot be concluded as a safe haven against other asset classes under investigation.Practical implicationsThe present study has implications for institutional investors looking to incorporate infrastructure in their multiasset portfolios for increased portfolio diversification benefits.Originality/valueDespite the increased influence of infrastructure as an asset class, to the best of the authors’ knowledge, this is the first study to investigate the hedge, safe haven and diversifying properties of infrastructure in a multi-asset context.

Safe haven properties of green, Islamic, and crypto assets and investor's proclivity towards treasury and gold

A search for a safe haven inspired by investors' loss aversion significantly exacerbates in times of turbulence. The same happened during the crisis of Covid-19 when recurring losses forced investors to alter their investment strategies, and the search for alternative investment classes picked momentum. This study evaluates the safe haven properties of Green financial products, Islamic assets, and Cryptocurrencies, which gained prominence in financial markets after the global financial crisis, coupled with the long-acknowledged safe haven assets like Gold, Silver, and Treasuries. We employ a quantile VAR framework to examine the connectedness between the assets' markets during stressed, normal, and euphoric periods. Our results show that both Green and Islamic Bonds only act as a safe haven during the normal market condition; however, US Treasury, cryptocurrencies, and gold emerged as safe-haven assets under bearish or extreme volatility periods. While proclivity towards US Treasury and gold supports the phenomenon of flight-to-safety, we find cryptos have also become investors' preference amid bearish trends finding their way into the list of safe havens for investors. • We evaluate the safe haven properties of Green, Islamic, and Crypto assets vis a vis gold and treasury securities. • Quantile VAR framework is used to examine the connectedness during the stressed, normal, and euphoric time periods. • Bonds in general, including Green and Islamic, only act as a safe haven during normal market conditions. • US Treasury, cryptocurrencies, and Gold-Silver emerged as safe-haven assets under bearish or extreme volatility periods. • In addition to US Treasury and Gold-Silver, the flight-to-safety, is observed towards cryptos as well.

Control of magnetoelastic coupling in Ni/Fe multilayers using He+ ion irradiation

This study reports the effects of post-growth He+ irradiation on the magneto-elastic properties of a Ni/Fe multi-layered stack. The progressive intermixing caused by He+ irradiation at the interfaces of the multilayer allows us to tune the saturation magnetostriction value with increasing He+ fluences and even to induce a reversal of the sign of the magnetostrictive effect. Additionally, the critical fluence at which the absolute value of the magnetostriction is dramatically reduced is identified. Therefore, insensitivity to strain of the magnetic stack is nearly reached, as required for many applications. All the above-mentioned effects are attributed to the combination of the negative saturation magnetostriction of sputtered Ni and Fe layers and the positive magnetostriction of the NixFe1−x alloy at the intermixed interfaces, whose contribution is gradually increased with irradiation. Importantly, the irradiation does not alter the layer polycrystalline structure, confirming that post-growth He+ ion irradiation is an excellent tool to tune the magneto-elastic properties of multilayer samples. An alternative class of spintronic devices can be envisioned with a material treatment able to arbitrary change the magnetostriction with ion-induced “magnetic patterning.”

Uniform calibration tests for forecasting systems with small lead time

A long noted difficulty when assessing calibration (or reliability) of forecasting systems is that calibration, in general, is a hypothesis not about a finite dimensional parameter but about an entire functional relationship. A calibrated probability forecast for binary events for instance should equal the conditional probability of the event given the forecast, whatever the value of the forecast. A new class of tests is presented that are based on estimating the cumulative deviations from calibration. The supremum of those deviations is taken as a test statistic, and the asymptotic distribution of the test statistic is established rigorously. It turns out to be universal, provided the forecasts “look one step ahead” only, or in other words, verify at the next time step in the future. The new tests apply to various different forecasting problems and are compared with established approaches which work in a regression based framework. In comparison to those approaches, the new tests develop power against a wider class of alternatives. Numerical experiments for both artificial data as well as operational weather forecasting systems are presented, and possible extensions to longer lead times are discussed.

Goodness-of-fit test for count distributions with finite second moment

A goodness-of-fit test for one-parameter count distributions with finite second moment is proposed. The test statistic is derived from the -distance of a function of the probability generating function of the model under the null hypothesis and that of the random variable actually generating data, when the latter belongs to a suitable wide class of alternatives. The test statistic has a rather simple form and it is asymptotically normally distributed under the null hypothesis, allowing a straightforward implementation of the test. Moreover, the test is consistent for alternative distributions belonging to the class, but also for all the alternative distributions whose probability of zero is different from that under the null hypothesis. Thus, the use of the test is proposed and investigated also for alternatives not in the class. The finite-sample properties of the test are assessed by means of an extensive simulation study.

MnO Enabling Highly Efficient and Stable Co‐Nx/C for Oxygen Reduction Reaction in both Acidic and Alkaline Media

AbstractIn situ growing transition metals on N‐doped carbon by atomic doping produces a class of promising alternatives to replace Pt‐based catalysts for redox reactions, yet still suffer from unsatisfactory activity and durability in acidic and basic media. Herein, a simple synthetic strategy to fabricate an MnO modifying Co‐Nx/C catalyst with high activity and robust durability is presented. The interphase engineering well controls the Co and N species in the carbon matrix, affording the material with more pyridine N and graphite N; the interaction between Co‐Nx and MnO phase is also well discussed. Accordingly, the obtained Co‐Nx/C‐MnO catalyst exhibits excellent electrocatalytic properties towards oxygen reduction reaction, achieving a half‐wave potential of 0.87 and 0.66 V versus reversible hydrogen electrode in 0.1 m KOH and 0.1 m HClO4 solutions, as well as excellent durability with only −16.9 and −12.2 mV shift after 1000 cycles, respectively. This study provides insights into the design of noble‐metal‐free electrocatalysts from the perspective of active sites and catalyst carriers.