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In the financial crisis and recession induced by the Covid-19 pandemic, many investment-grade firms became unable to borrow from securities markets. In response, the Fed not only reopened its commercial paper funding facility but also announced it would purchase newly issued and seasoned corporate bonds rated as investment grade before the Covid pandemic. We assess the effectiveness of this program using long sample periods, spanning the Great Depression through the Great and Covid Recessions. Findings indicate that the announcement of corporate bond backstop facilities helped stop risk premia from rising further than they had by late-March 2020. In doing so, these backstop facilities limited the role of external finance premia in amplifying the macroeconomic impact of the Covid pandemic. Nevertheless, the corporate bond programs blend the roles of the Federal Reserve in conducting monetary policy via its balance sheet, acting as a lender of last resort, and pursuing credit policies.
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Objective: China and the United States (the U.S.) have the heaviest colorectal cancer (CRC) burden with considerable variations in temporal trends. This study aims to analyze the temporal patterns of CRC burden and its risk factors in China and the U.S. across the past three decades. Methods: Data were extracted from the Global Burden of Disease (GBD) Study in 2019, including cases, deaths, disability-adjusted life-years (DALYs), age-standardized rate (ASR), and summary exposure value (SEV) of CRC in China and the U.S. between 1990 and 2019. Annual average percentage changes (AAPCs) of CRC burden were calculated using the Joinpoint regression model. The mortality in CRC attributable to potential risk factors was characterized by countries, gender, and age groups. Results: In 2019, there were 607,900 and 227,241 CRC cases, and 261,777 and 84,026 CRC deaths in China and the U.S., respectively. The age-standardized incidence rate (ASIR) was 30.55 per 100,000 in China and 41.86 per 100,000 in the U.S., and the age-standardized mortality rate (ASMR) was 13.86 per 100,000 in China and 14.77 per 100,000 in the U.S. CRC incidence, mortality, and DALY rate in the U.S. showed downward trends in the past three decades (AAPC=-0.47, -1.06, and -0.88, respectively), while upward trends were observed in China (AAPC=3.11, 1.05, and 0.91, respectively). Among the cause of CRC, the leading risk factor contributing to CRC death was low milk in China and smoking in the U.S., respectively. Conclusions: From 1990 to 2019, the burden of CRC in China increased dramatically, particularly for males and middle-aged and elderly people. The management of the major risk factors associated with the high burden of CRC should be enhanced.
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In this work, we use observations and experimental emissions in a version of NOAA's National Air Quality Forecasting Capability to show that the COVID-19 economic slowdown led to disproportionate impacts on near-surface ozone concentrations across the contiguous U.S. (CONUS). The data-fusion methodology used here includes both U.S. EPA Air Quality System ground and the NASA Aura satellite Ozone Monitoring Instrument (OMI) NO2 observations to infer the representative emissions changes due to the COVID-19 economic slowdown in the U.S. Results show that there were widespread decreases in anthropogenic (e.g., NOx) emissions in the U.S. during March-June 2020, which led to widespread decreases in ozone concentrations in the rural regions that are NOx-limited, but also some localized increases near urban centers that are VOC-limited. Later in June-September, there were smaller decreases, and potentially some relative increases in NOx emissions for many areas of the U.S. (e.g., south-southeast) that led to more extensive increases in ozone concentrations that are partly in agreement with observations. The widespread NOx emissions changes also alters the O3 photochemical formation regimes, most notably the NOx emissions decreases in March-April, which can enhance (mitigate) the NOx-limited (VOC-limited) regimes in different regions of CONUS. The average of all AirNow hourly O3 changes for 2020-2019 range from about +1 to -4 ppb during March-September, and are associated with predominantly urban monitoring sites that demonstrate considerable spatiotemporal variability for the 2020 ozone changes compared to the previous five years individually (2015-2019). The simulated maximum values of the average O3 changes for March-September range from about +8 to -4 ppb (or +40 to -10%). Results of this work have implications for the use of widespread controls of anthropogenic emissions, particularly those from mobile sources, used to curb ozone pollution under the current meteorological and climate conditions in the U.S.
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Informal caregivers immersed in the daily care of loved ones at end-of-life stages face such challenges as medical and household issues, worries, doubts, and uncertainties. Using a macro-mezzo-micro approach to discourse, we analyzed parent study interview data involving 46 caregivers facing end-of-life realities. At the mezzo level, we examined caregivers' expressed perceptions of control. We then more finely analyzed discursive expressions of affective stances pertaining to caregivers' emotions and feelings, and epistemic stances pertaining to their knowledge and belief states. Theories of uncertainty and control inextricably interweave areas of cognition, affect, and behavior regarding how caregivers perceive their realities and how they engage in or disengage from coping mechanisms in the process. The findings in this three-tiered approach make salient specific discursive patterns gleaned from systematic and fastidious attention to caregivers' own ways of using language that methodically afford deeper entry into the emotional, physical, and cognitive challenges in their everyday lived experiences.
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Adaptação Psicológica , Cuidadores/psicologia , Emoções , Humanos , Pesquisa Qualitativa , Qualidade de Vida , Assistência Terminal , Incerteza , Estados UnidosRESUMO
Ryff's Psychological Well-Being (PWB) Scale is a theoretically derived instrument that focuses on six dimensions of eudaimonic well-being. Although the PWB scale has been widely used in both clinical and general samples with different sociodemographic characteristics, its factor structure within first-generation Korean immigrant mothers require examination, as they often face socio-cultural challenges due to immigration (e.g., experiencing acculturation stress, being socially and culturally segregated, following heritage cultural obligations to be a "wise mother and good wife," taking less prestige jobs, etc.) that could negatively influence their well-being. This study examined the factor structure of an 18-item version of the PWB Scale in a sample of 169 first-generation Korean immigrant mothers of young children in the U.S. A second-order confirmatory factor analysisdid not support the original factor structure of the PWB scale. More importantly, high correlations among some of the PWB subscales suggested that the PWB factors may not be distinct from each other and the number of factors should be reduced. Exploratory factor analysis was conducted on the four highly correlated factors in subsequent analyses and three new factors (Satisfaction with Life, Goal Orientation, and Positive Self-Perceptions) were identified. The newly derived PWB factors were negativelycorrelated with mothers' depressive symptoms.These findings advanced our understanding of psychological well-being in first-generation Korean immigrant mothersand highlighted the need to consider socio-cultural factors in mental health research on this population.
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We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be "geographically isolated" (sensu Tiner Wetlands 23:494-516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be "geographically isolated" shows the difficulties in grouping an ecological resource that does not reliably indicate lack of surface water connectivity in order to meet legal, regulatory, or scientific needs. Additionally, the practice of identifying "geographically isolated wetlands" based on distance from a stream can result in gross overestimates of the number of wetlands lacking ecologically important surface-water connections. Our findings do not support use of the overly simplistic label of "geographically isolated wetlands". Wetlands surrounded by uplands vary in function and surface-water connections based on wetland landscape setting, context, climate, and geographic region and should be evaluated as such. We found that the "geographically isolated" grouping does not reflect our understanding of the hydrologic variability of these wetlands and hence does not benefit conservation of the Nation's diverse wetland resources. Therefore, we strongly discourage use of categorizations that provide overly simplistic views of surface-water connectivity of wetlands fully embedded in upland landscapes.
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This article examines the similarities and differences in the education and training of gerontologists and others who work with older people in Sweden and the United States. It outlines the aging trends in both countries and assesses the level of training for those who provide care in a variety of fields. Both countries are aging, but the programs for gerontological training are quite different in the two countries, reflecting underlying cultural values. Sweden's education is generally more oriented toward the integration of some aging education in more disciplinary fields, such as nursing and social work and thus could benefit from more specialized, aging-specific courses. The United States is highly specialized, with multiple programs in various subfields of aging (e.g., geropsychology; aging services administration) and could benefit from integrating more aging knowledge into courses in other disciplines. The authors challenge professionals to consider if there is a basic but global curriculum and/or set of competencies in gerontology that could be agreed upon. As an increasingly global village, the ability to share and learn is more easily achievable. Sweden and the United States have much to learn from each other in terms of appropriately educating and training those who support our older people.
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Competência Clínica , Geriatria/educação , Pessoal de Saúde/educação , Dinâmica Populacional/estatística & dados numéricos , Serviço Social/educação , Idoso , Idoso de 80 Anos ou mais , Comparação Transcultural , Currículo , Humanos , Relações Interprofissionais , Medicina/estatística & dados numéricos , Grupos Minoritários/estatística & dados numéricos , Competência Profissional , Suécia , Estados Unidos , Recursos HumanosRESUMO
The Tuskegee Study of Untreated Syphilis in the Negro Male was an observational study on African-American males in Tuskegee, Alabama between 1932 and 1972. The U. S. Public Health Service ran this study on more than 300 people without notifying the participants about their disease nor treating them even after the introduction of penicillin. The study included recording the progress of disease and performing an autopsy on the deaths. This paper explores historical backgrounds enabled this infamous study, and discusses three driving forces behind the Tuskegee Study. First, it is important to understand that the Public Health Service was established in the U. S. Surgeon General's office and was operated as a military organization. Amidst the development of an imperial agenda of the U.S. in the late 19th and early 20th centuries, the PHS was responsible for protecting hygiene and the superiority of "the American race" against infectious foreign elements from the borders. The U.S. Army's experience of medical experiments in colonies and abroad was imported back to the country and formed a crucial part of the attitude and philosophy on public health. Secondly, the growing influence of eugenics and racial pathology at the time reinforced discriminative views on minorities. Progressivism was realized in the form of domestic reform and imperial pursuit at the same time. Major medical journals argued that blacks were inclined to have certain defects, especially sexually transmitted diseases like syphilis, because of their prodigal behavior and lack of hygiene. This kind of racial ideas were shared by the PHS officials who were in charge of the Tuskegee Study. Lastly, the PHS officials believed in continuing the experiment regardless of various social changes. They considered that black participants were not only poor but also ignorant of and even unwilling to undergo the treatment. When the exposure of the experiment led to the Senate investigation in 1973, the participating doctors of the PHS maintained that their study offered valuable contribution to the medical research. This paper argues that the combination of the efficiency of military medicine, progressive and imperial racial ideology, and discrimination on African-Americans resulted in the Tuskegee Syphilis Experiment.
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Negro ou Afro-Americano/história , Experimentação Humana não Terapêutica/história , Racismo/história , Sífilis/história , United States Public Health Service/história , Alabama , História do Século XX , Humanos , Masculino , Medicina Militar/história , Experimentação Humana não Terapêutica/ética , Sujeitos da Pesquisa/história , Estados Unidos , Suspensão de Tratamento/históriaRESUMO
Streptogramins are potent drugs against numerous highly resistant pathogens and therefore are used as antibiotics of last-resort human therapy. They consist of a mixture of two different types of chemical substances - the group A streptogramins, which are polyunsaturated macrolactones, and the group B streptogramins, representing cyclic hexadepsipeptides. Streptogramins are unique in their mode of action: each component alone exhibits a moderate bacteriostatic activity by binding to the bacterial 50S ribosomal subunit and thereby blocking translation, whereas the synergic combination of both substances is up to hundred fold more effective than the single compounds, resulting in a bactericidal activity. The streptogramin biosynthetic genes are organized as large antibiotic superclusters. These clusters harbour numerous regulatory genes, which encode different types of regulators that together form a complex hierarchical signalling system, which governs the regulation of streptogramin biosynthesis. Resistance is also regulated by this cascade. However, whereas resistance against streptogramins is quite well understood in diverse pathogenic organisms, only little is known about how the natural producer strains protect themselves against these toxic compounds. Here, we give an overview about the recent advances in streptogramin investigations with a main focus on the best-studied representatives, pristinamycin and virginiamycin. We concentrate on the biosynthesis of these compounds, their regulation and resistance determinants as well as their application in medicine and food industry.
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Antibacterianos/farmacologia , Vias Biossintéticas/genética , Farmacorresistência Bacteriana , Viabilidade Microbiana/efeitos dos fármacos , Pristinamicina/farmacologia , Virginiamicina/farmacologia , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/uso terapêutico , Sinergismo Farmacológico , Indústria Alimentícia , Humanos , Pristinamicina/biossíntese , Pristinamicina/química , Pristinamicina/uso terapêutico , Virginiamicina/biossíntese , Virginiamicina/química , Virginiamicina/uso terapêuticoRESUMO
Street connectivity, defined as the number of (3-way or more) intersections per area unit, is an important index of built environments as a proxy for walkability in a neighborhood. This paper examines its geographic variations across the rural-urban continuum (urbanicity), major racial-ethnic groups and various poverty levels. The population-adjusted street connectivity index is proposed as a better measure than the regular index for a large area such as county due to likely concentration of population in limited space within the large area. Based on the data from the Behavioral Risk Factor Surveillance System (BRFSS), this paper uses multilevel modeling to analyze its association with physical activity and obesity while controlling for various individual and county-level variables. Analysis of data subsets indicates that the influences of individual and county-level variables on obesity risk vary across areas of different urbanization levels. The positive influence of street connectivity on obesity control is limited to the more but not the mostly urbanized areas. This demonstrates the value of obesogenic environment research in different geographic settings, helps us reconcile and synthesize some seemingly contradictory results reported in different studies, and also promotes that effective policies need to be highly sensitive to the diversity of demographic groups and geographically adaptable.
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Introduction: Mazes are linguistic disfluencies such as filled pauses, repetitions, or revisions of grammatical, phonological, or lexical aspects of words that do not contribute to the meaning of a sentence. Bilingual children are believed to increase the numbers of mazes in their native or heritage language, the minority language, as they become more proficient in the second language, the societal language. Mazes may increase over time in bilingual Spanish-speaking children as they become more proficient in English, the societal language in the United States. However, current studies have not been conducted longitudinally. Higher rates of mazes in the heritage language over time may be due to changes in language proficiency and differences in processing demands in the children as they use more complex language. Moreover, children with developmental language disorder (DLD) can also present higher rates of mazes than children with typical language. Heritage speakers, therefore, are at risk of being misdiagnosed with DLD due to high rates of mazes. Currently, we do not understand what the typical rates of mazes are as heritage speakers get older and become more proficient in the societal language. The current study examined the type and frequency of Spanish mazes longitudinally in a group of 22 Spanish heritage speakers with and without DLD and determined the changes over time. Methods: A total of 11 children with typical language development (TLD) and 11 with DLD participated in this 5-year longitudinal study. Using a wordless picture book, children completed a retelling task in Spanish during the spring of each academic year (PK to 3rd grade) as part of a 5-h testing battery. Narratives were transcribed and coded for types of mazes (filled pauses, repetitions, grammatical revisions, phonological revisions, and lexical revisions). Results and conclusion: The results of the study indicate that TLD children increased their overall percentage of mazed words and utterances. The opposite pattern was observed in the DLD group, which decreased their percentage of mazed words and utterances. In contrast, both groups demonstrated a decrease in repetitions in first grade and an increase in third grade. Additionally, the TLD and DLD children decreased in the percentage of fillers in first grade and then increased in the third grade. Results suggest that maze use is quite variable in heritage speakers and does not necessarily differentiate groups. Clinicians should not rely solely on mazes to determine ability status. In fact, high use of mazes can reflect typical language development.
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This study investigates the development of military medicine during the Korean War, with a focus on the role of the Medical Field Service School and training programs in the United States. It also explores the nuanced acceptance of American medicine by South Korean doctors. Military surgeon education and training emerged as pivotal catalysts, initiating a qualitative transformation in South Korean medicine and serving as a catalyst for the advancement of modern medical practices. Military surgeon education went beyond imparting military knowledge to civilian doctors; it also acted as a vehicle for disseminating fundamental medical knowledge essential for the progress of Korean medicine. Noteworthy is the strategic selection of exceptional military surgeons for overseas training, serving as a vital link for the assimilation of 'advanced medicine' across diverse medical domains. Contrary to unilateral acceptance, South Korean doctors embraced American medicine based on subjective judgments aligned with the specific needs of South Korean medicine. Acknowledging American medical knowledge and technology through the Medical Field Service School and U.S. training, military surgeons refrained from mere praise, recognizing the substantial gaps between South Korean and American military medicine. Beyond material achievements, South Korean military surgeons also discerned and valued the spiritual legacy of American medicine. These military surgeons actively determined the essential medical majors for South Korea, introducing cutting-edge medical technology, and leveraging relationships with U.S. military surgeons to facilitate opportunities for themselves and their students to study abroad. This proactive approach highlights the independent thought processes of South Korean military surgeons, addressing both material and spiritual needs and serving as internal driving forces for the development of South Korean medicine.
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Medicina , Medicina Militar , Humanos , Estados Unidos , Guerra da Coreia , República da Coreia , Instituições AcadêmicasRESUMO
Relatively little is known about how heritage speakers process language in real time, despite recent calls for the use of online methods such as self-paced reading, eyetracking, and ERPs (event-related potentials) in research on this early bilingual population. The present study addressed this gap with an empirical study of the online processing of heritage speakers of Spanish in the U.S. using self-paced reading, which is the online method that is most accessible to a wide body of researchers because it does not require specialized equipment. The processing target was related to the online integration of verb argument specifications, which was chosen because it does not involve ungrammatical sentences and therefore may be less likely to involve metalinguistic knowledge and less likely to put heritage speakers at a disadvantage than measures that rely on the recognition of grammatical errors. More specifically, this study examined an effect that occurs when a noun phrase appears after an intransitive verb, which can cause processing difficulty relative to a comparison condition in which the verb is transitive. The participants were 58 heritage speakers of Spanish and a comparison group of 16 first-generation immigrants raised in Spanish-speaking countries. Both groups showed the expected transitivity effect on the post-verbal noun phrase during self-paced reading, but the heritage speaker group also showed a spillover effect on the post-critical region. Among the heritage speakers, these effects were associated with lower self-ratings for reading skill in Spanish and with slower average reading speed during the experiment. Three theoretical accounts of the apparent susceptibility to spillover effects among heritage speakers are proposed: that it is a characteristic of shallow processing, that it is due to underdeveloped reading skill, and that it is an artifact of the self-paced reading method. The latter two possibilities are especially consistent with a role for reading skill in these results.
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This study examined factors related to respite service use among caregivers and further tested the moderating effect of dementia caregiver status in these relationships using nationally representative U.S. data. Logistic regression analyses were conducted among 1203 caregivers (276 dementia and 927 nondementia caregivers). Caregivers' race and ethnicity as a predisposing factor, caregivers' self-rated health as an enabling factor, and care recipients' living arrangement and functional limitations as need factors were significantly related to respite service use. Moreover, dementia caregiver status moderated the association between enabling factors (i.e., household income, work status, and self-rated health) and respite service use. Our findings imply that dementia caregivers may be more in need of respite service use than nondementia caregivers when they have limited enabling factors (e.g., lower household income, nonworking status, poorer health). Policy and practice efforts that specifically support enabling factors are suggested to promote more respite service use among dementia caregivers.
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Cuidadores , Demência , Demência/terapia , Etnicidade , Humanos , Cuidados Intermitentes , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Birthweight is a widely accepted indicator of infant health and has significant and lasting associations. Several studies have found that low and high birthweight have significant negative associations with adult health. A new study in the field of social sciences has established that birthweight has significant negative associations with not only adult health but also social attributes, such as income and occupation; however, no studies have evaluated the associations between birthweight and quality-of-life (QOL) attributes such as happiness. METHODS: In this study, we use data from Japan, the U.S., and India, collected in 2011, in which the respondents were asked about their own birthweights to examine the long-term associations between low and high birthweight and eight outcome variables related to the QOL: adolescent academic performance, height, education, marital status, body mass index, income, health, and happiness. We regressed each of the eight outcome variables on low and high birthweight and the interaction terms of the old age and the birthweight dummies for each country. We estimated both the reduced and the recursive-structural forms. While the former estimates the total, that is, the sum of direct and indirect associations between birthweight and each outcome, the latter reports the direct association between birthweight and each outcome. RESULTS: In Japan, while low birthweight is negatively associated with all outcomes, the associations of high birthweight were limited. In the U.S., low birthweight was not associated with any outcomes, but high birthweight had significantly negative associations with health and happiness. In contrast, in India, high birthweight was significantly and positively associated with income, health, and happiness, while low birthweight was associated with several outcomes negatively, similar to Japan. These associations were stronger in youth than in old age. CONCLUSION: Our study demonstrated that the associations of birthweight with QOL are widely diversified across countries: low birthweight, rather than high birthweight, is a problem in Japan and India. However, the opposite is true for the U.S., indicating that policymakers in developed countries must pay closer attention to the problems caused by high birthweight, whereas those in developing countries are better to focus on low birthweight.
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Background: Social capital is a well-known health determinant with both relational and geographic aspects. It can help mitigate adverse events and has been shown to impact behaviors and responses during the COVID-19 pandemic. Mental health has declined during the COVID-19 pandemic, and social capital, may serve to buffer those declines. Methods: Building from this, we assessed whether pre-pandemic social capital and contemporaneous social policy, which included indicators of social trust, civic participation, and presence of mask mandates, affected pandemic mental health, measured as the percent of the population experiencing symptoms of depression and anxiety at the state level. Results: Generalized social trust and state mask mandates were significantly associated with lower levels of depression and anxiety. Conversely, states with greater civic engagement prior to the pandemic experienced more anxiety and depression. Conclusions: Findings suggest that existing social capital, particularly social trust, may protect against anxiety and depression and contribute to community resilience during times of adversity. States should invest in policies and programs that increase social trust.
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COVID-19 , Capital Social , COVID-19/epidemiologia , COVID-19/prevenção & controle , Estudos Transversais , Humanos , Saúde Mental , Pandemias , Apoio SocialRESUMO
Objectives: The aim of this study was to examine the association of per- and polyfluoroalkyl (PFAS) concentrations and allostatic load (AL) by the county of birth and the length of time in the United States of America (U.S.), in a representative sample of U.S. adults. Methods: Data from the 2007−2014 National Health and Nutrition Examination Survey (NHANES) were used in this cross-sectional study on the U.S. adults aged 20 and older. The analysis was stratified by the length of time in the U.S. and by the county of birth. In all, the sample contained those who were US-born (n = 10,264), Mexico-born (n = 4018), other Spanish speaking country-born (n = 2989), and other not−Hispanic speaking country-born (n = 3911). Poisson models were used to assess the differences in AL and PFAS levels depending on country of birth and length of time in the U.S. Results: Estimates indicated that those born in Other non−Spanish speaking counties had the highest PFAS levels among the country of birth category in the database. Regarding length of time in the U.S., those born in Mexico had low PFAS levels when their length of time in the U.S. was short. The Mexico-born category presented the most at-risk high serum PFAS levels, with AL levels increasing by length of time in the U.S. (p-value < 0.001). Conclusion: This study found that PFAS concentrations increased by the length of time residing in the U.S. Those born in other non−Hispanic counties had the highest PFAS levels among all the categories. In general, AL and PFAS levels are mostly associated with the length of time in the U.S., with foreign-born individuals having increased levels of both the longer they stay.
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Alostase , Poluentes Ambientais , Fluorocarbonos , Adulto , Estudos Transversais , Feminino , Hispânico ou Latino , Humanos , Inquéritos Nutricionais , Estados UnidosRESUMO
A mature and hybrid machine-learning model is verified by mature empirical analysis to measure county-level COVID-19 vulnerability and track the impact of the imposition of pandemic control policies in the U.S. A total of 30 county-level social, economic, and medical variables and a timeline of the imposed policies constitutes a COVID-19 database. A hybrid feature-selection model composed of four machine-learning algorithms is developed to emphasize the regional impact of community features on the case fatality rate (CFR). A COVID-19 vulnerability index (COVULin) is proposed to measure the county's vulnerability, the effects of model's parameters on mortality, and the efficiency of control policies. The results showed that the dense counties in which minority groups represent more than 45% of the population and those with poverty rates greater than 24% were the most vulnerable counties during the first and the last pandemic peaks, respectively. Highly-correlated CFR and COVULin scores indicated a close agreement between the model outcomes and COVID-19 impacts. Counties with higher poverty and uninsured rates were the most resistant to government intervention. It is anticipated that the proposed model can play an essential role in identifying vulnerable communities and help reduce damages during long-term alike disasters.
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We investigate the behavior of stock prices to variations in COVID19 infection rate over time. To study the inter-temporal impact of the pandemic on major stock indexes, we apply factor model, and disaggregate the sample period in three COVID19 waves. We bring interesting evidence on the so-called immune behavior of stock indexes. While no signs of stock market immunity to the disease were confirmed, the opportunities created by the pandemic would help new winners, causing a shift of sectoral gains. Distinguishing the surges from plunges in the COVID19 infections, we observe the behavior of stock indexes towards different scenarios during the pandemic. While the conventional wisdom may lead to an overall probable pessimistic outcome, we find that diversity and speedy adjustment based on new business models resulted in sizable theoretical inconsistencies and asymmetries in the response of stock indexes to the pandemic.
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The COVID-19 pandemic, which originated in Wuhan, China, precipitated the stock market crash of March 2020. According to published global data, the U.S. has been most affected by the tragedy throughout this outbreak. Understanding the degree of integration between the financial systems of the world's two largest economies, particularly during the COVID-19 pandemic, necessitates thorough research of the risk transmission from China's stock market to the U.S. stock market. This study examines the volatility transmission from the Chinese to the U.S. stock market from January 2001 to October 2020. We employ a variant form of the EGARCH (1,1) model with long-term control over the excessive volatility breakpoints identified by the ICSS algorithm. Since 2004, empirical evidence indicates that the volatility shocks of the Chinese stock market have frequently and negatively affected the volatility of the U.S. stock market. Most importantly, we explore that the COVID-19 pandemic vigorously and positively promoted the volatility infection from the Chinese equity market to the U.S. equity market in March 2020. This precious evidence endorses the asymmetric volatility transmission from the Chinese to the U.S. stock market when COVID-19 broke out. These experimental results provide profound insight into the risk contagion between the U.S. and China stock markets. They are also essential for securities investors to minimize portfolio risk. Furthermore, this paper suggests that globalization has carefully driven the integration of China's stock market with the international equity markets.