bluuebunny/crossref_metadata_2025 huggingface dataset:
International Students’ Perceptions of and Attitudes towards their Chinese Accented English in Academic Contexts
Authors:   Excelsia College, Veliz Leonardo , Veliz-Campos Mauricio ,   Universidad de Talca
Published: June 2024

Dominant processes of economic and cultural globalization have accelerated the use of English as a medium of instruction and precipitated diverse, yet intersected global student mobility, which have resulted in varied forms and uses of English in academic contexts. The present study reports on the findings of research into the attitudes and perceptions of a group of Chinese students studying English as an Additional Language (EAL) towards the legitimacy of non-native speaker (NNS) accents, including their own, as used in cross-cultural interactions in academic contexts. The research aims at unpacking students' views of their Chinese accented English to better understand the ways in which their attitudes towards English accents help negotiate and sustain their ethnic identities in academic contexts. Drawing on a qualitative paradigm, the study utilized in-depth interviews with a sample of four participants. The results suggested that intelligibility is highly regarded at least at the cognitive level, which gives their idiolectal varieties of English greater legitimacy. However, such a hard-developed belief is seriously thwarted by their lived experiences of discrimination over their accented speech, which pushes them back, yet again, to a position of perceived inferiority that hinders their active participation in their academic contexts.
Investigating the Development of Speaking Skill through Language Games in Technologically Underequipped EFL Classroom
Authors:   Indian Institute of Technology Patna, Saha Sujay Kumar , Singh Smriti
Published: June 2024

In recent years, language games have become a matter of interest for educators not only because of their po-tential to enhance language learning experiences, but also in the support they give towards creating a multi-modal and interactive classroom environment that leads children towards perceptual, behavioural, emotional and cognitive development (Reinders, 2016). The researchers in the present study have used various language games in the EFL classroom to investigate the effectiveness of language games to develop the speaking skill of learners, especially in a vernacular medium school using Action Research Model. The results of the study showed that there is a positive change in the classroom atmosphere where learners get opportunities to speak as well as develop the learners' speaking skill. The result is discussed using action research cycles. This partic-ular study addresses the effectiveness of games to develop the speaking skill of learners in a vernacular medi-um school, located in Murshidabad, India.
Reliability of the Hop Test and Asymmetry Index in University Athletes: A Cross-Sectional Study Assessing Injury Risk
Authors: Kayhan Recep Fatih , Karadağ Alper , Terzi Esranur
Published: June 2024

This study aims to assess the reliability of hop tests among healthy university athletes and to identify leg asymmetries through these assessments. A cohort of 212 university athletes, active in sports, participated in the study. Hop tests, comprising four distinct procedures, were administered to evaluate lower extremity strength. The hop tests demonstrated high reliability, with reliability coefficients ranging from 0.704 to 0.990. Examination of asymmetry indices revealed mean values of 101.07%, indicative of symmetrical limb function among participants. Gender-based differences were notable in hop test results, particularly in the crossover hop test, which showed significant asymmetry (p
On the Development of Motivation and Positive Attitude to Chemistry
Authors:   Gymnasium no. 1, Irkutsk, Demidova O. E.
Published: June 2024

The article discusses ways to develop motivation and a positive attitude to Chemistry in students through the activation of the structural link of the individual’s internal position of “Name”.
Interdisciplinary Task for the Formation of Natural Science Literacy
Authors:   National Research Center «Kurchatov Institute», Moscow, Asanova L. I.
Published: June 2024

The article touches upon the problem of forming objective ideas among schoolchildren about hydrogen as an alternative energy source. An example of a complex task for developing natural science literacy is presented, the content of which is related to the problem under consideration.
Mechanism of barotaxis in marine zooplankton
Authors: Calderón Luis Alberto Bezares , Shahidi Réza , Jékely Gáspár
Published: June 2024

Hydrostatic pressure is a dominant environmental cue for vertically migrating marine organisms but the physiological mechanisms of responding to pressure changes remain unclear. Here we uncovered the cellular and circuit bases of a barokinetic response in the planktonic larva of the marine annelid
Platynereis dumerilii
. Increased pressure induced a rapid, graded and adapting upward swimming response due to the faster beating of cilia in the head multiciliary band. By calcium imaging, we found that brain ciliary photoreceptors showed a graded response to pressure changes. The photoreceptors in animals mutant for
ciliary opsin-1
had a smaller sensory compartment and mutant larvae showed diminished pressure responses. The ciliary photoreceptors synaptically connect to the head multiciliary band via serotonergic motoneurons. Genetic inhibition of the serotonergic cells blocked pressure-dependent increases in ciliary beating. We conclude that ciliary photoreceptors function as pressure sensors and activate ciliary beating through serotonergic signalling during barokinesis.
Combining radio-telemetry and radar measurements to test optimal foraging in an aerial insectivore bird
Authors: Bloch Itai , Troupin David , Toledo Sivan , Nathan Ran , Sapir Nir
Published: June 2024

Optimal foraging theory posits that foragers adjust their movements based on prey abundance to optimize food intake. While extensively studied in terrestrial and marine environments, aerial foraging has remained relatively unexplored due to technological limitations. This study, uniquely combining BirdScan-MR1 radar and the Advanced Tracking and Localization of Animals in Real-Life Systems biotelemetry system, investigates the foraging dynamics of Little Swifts (Apus affinis) in response to insect movements over Israel’s Hula Valley. Insect movement traffic rate (MoTR) substantially varied across days, strongly influencing swift movement. On days with high MoTR, swifts exhibited reduced flight distance, increased colony visit rate, and earlier arrivals at the breeding colony, reflecting a dynamic response to prey availability. However, no significant effects were observed in total foraging duration, flight speed, or daily route length. Notably, as insect abundance increased, inter-individual distances decreased. These findings suggest that Little Swifts optimize their foraging behavior in relation to aerial insect abundance, likely influencing reproductive success and population dynamics. The integration of radar technology and biotelemetry systems provides a unique perspective on the interactions between aerial insectivores and their prey, contributing to a comprehensive understanding of optimal foraging strategies in diverse environments.
The impact of the military conflict in Sudan on maternal health: a mixed qualitative and quantitative study
Authors: Miskeen Elhadi
Published: June 2024

Objectives

Ongoing military conflict in Sudan has had significant repercussions on the health and well-being of the population, particularly among women of reproductive age. This study aimed to investigate the impact of conflict on maternal health by employing a mixed qualitative and quantitative research approach.

Methods

Through in-depth interviews and survey questionnaires (388 women), this study examined the experiences and challenges faced by pregnant women and new mothers and the availability and accessibility of maternal healthcare services in conflict-affected areas. Using a qualitative approach, in-depth interviews were conducted with 35 women who had recently given birth or were pregnant in regions affected by the Khartoum State–Sudan conflict. Thematic analysis was used to analyze the data collected from the interviews.

Result

Most women did not have access to healthcare services (86.6%), and out of the total sample, 93 (24%) experienced adverse outcomes. The factors associated with adverse effects were parity (OR 1.78, CI [1.15–2.75], p-value 0.010), gestational age (OR 2.10, CI [1.36–3.25], p-value 0.002), access to healthcare (OR 2.35, CI [1.48–3.72], p-value 0.001), and delivery mode (OR 1.68, CI [1.05–2.69], p = 0.030). Factors significantly associated with accessibility to maternal healthcare services included age (OR, 1.28; = 0.042) and higher conflict levels (1.52 times higher odds, p = 0.021). The narratives and experiences shared by women exposed the multifaceted ways in which the conflict-affected maternal health outcomes.

Conclusion

The significance of this study lies in its potential to contribute to the existing literature on maternal health in conflict-affected areas, especially in Sudan, and to help us understand how women can receive maternal health services.
Occupational Chemical Carcinogenesis
Authors: Huff James , Melnick Ronald L.
Published: August 2012

Workers are exposed to carcinogens and carcinogenic exposure circumstances, as well as to many other agents considered probably, possibly, or reasonably anticipated to be human carcinogens. Covered herein are occupational carcinogens: chemicals, uncharacterized exposure circumstances, and occupations/workplaces known or suspected to cause cancer in workers, and agents causing cancers in animal bioassays, which are proven predictive for human cancers. Importantly, individuals differ in susceptibility for developing cancer due to exposure to a carcinogenic substance; factors influencing cancer outcomes include exposure circumstances, genetic differences, lifestyle, health condition, age, and gender. Identification of agents as carcinogens is based on information from epidemiological studies, long‐term animal studies, in vitro and in vivo evaluations, and assessments of mechanistic data and structure‐activity relationships. Various agencies, such as IARC, NTP, U.S. EPA, CalEPA, and others have developed classification schemes that categorize potential carcinogenicity of environmental and industrial agents in humans based on strength‐of‐evidence from human studies, animal studies, and mechanistic information. Categorizations formulated by authoritative bodies serve as the initial basis for standard's settings and regulatory actions. Several health and safety laws have been promulgated to protect workers from harmful effects of hazardous agents in the workplace. Risk characterization provides an integrative summary of available and relevant information on hazard identification, exposure assessment, and dose‐response relationships that have been used to estimate potential human cancer risks under various exposure circumstances. This information serves as the basis for risk management decisions on the extent to which workers' exposures to hazardous agents should be controlled. Likewise reducing or eliminating exposures to known and suspected carcinogens will reduce or prevent the incidences of occupational cancers. The World Health Organization reports occupational carcinogens are responsible for ∼152,000 cancer deaths per year and cancer prevention is essential because ∼40% of all cancer deaths can be prevented.
Wood Dust
Authors: Dement John
Published: August 2012

Wood dust is any particle arising from processing or handling wood. Woods are classified into two broad botanical classifications: hardwood is the common name given to the botanical classification angiosperms, and softwood is the common name given to the botanical classification gymnosperms. Gymnosperms have exposed seeds whereas angiosperms have encapsulated seeds. Although there are more than 12,000 species of trees recorded, most species are deciduous trees or hardwoods, and only about 800 species are coniferous trees or softwoods.

This chapter discusses production and uses of wood. Wood use depends on availability. Biologically active organic compounds in wood are described. Wood dust is not a component of the ambient environment except in the vicinity of woodworking operations. Toxicity information is given for populations exposed to wood dust (mill workers, furniture makers, etc.). Diseases studied include nonmalignant lung disease, lung cancer, digestive cancer, and Hodgkin's disease. Wood exposure limits for hardwoods and softwoods are listed.
Cotton and Other Textile Dusts
Authors: Merchant James A.
Published: August 2012

The production of cotton products is commercially important to developed and developing countries alike. Processing of flax and hemp remains regionally important industries, which continue to provide traditional textile products. It has been reported that millions of workers are occupationally exposed to these vegetable dusts worldwide. It is now clear that symptoms typical of byssinosis in the textile industry are observed among those occupationally exposed to vegetable dust arising from the processing of cotton, flax, hemp, and other textile fibers. Several investigations have provided a good understanding regarding the epidemiology of byssinosis. It has been observed that exposure to textile vegetable dusts lead to increase prevalence of nonspecific airway symptoms, modest cross‐shift declines in spirometry, and progressive declines in lung function that may result in significant lung impairment. Linear dose‐response relationships have been observed between byssinosis prevalence, cross‐shift declines in FEV1, and concentration of inhalable cotton dust and endotoxin. These findings have led to regulation of cotton dust in the United States and in several other countries.
Tuberculosis and Other Mycobacteria
Authors: Yadav Jagjit S. , Kapoor Renuka
Published: August 2012

Mycobacteria are a group of microbial pathogens associated with tuberculosis (TB), one of the world's most prevalent human disease and several nontuberculous diseases in humans. Another major human infection caused by this genus is leprosy. TB is predominantly a pulmonary disease infecting lungs but extrapulmonary TB is also prevalent and includes lymphatic, pleural, meningeal, pericardial, skeletal, gastrointestinal, genitourinary, or miliary form. The genusMycobacteriumcomprises of about 130 species that are groupable into two major categories: (A) theMycobacterium tuberculosiscomplex: it comprises of two obligate pathogenic species, namelyM. tuberculosis(the agent of tuberculosis) andMycobacterium leprae(the agent of leprosy). This complex contains four other species of mycobacteria that also cause TB viz.,Mycobacterium bovis,Mycobacterium africanum,Mycobacterium microti, andMycobacterium canetti. (B) The nontuberculous mycobacteria (also called atypical mycobacteria or environmental mycobacteria): this group comprises of a large number of saprophytic species that live freely in the environment such as in soils, water, and other organic matrices. These organisms may be inhaled via dust particles or ingested via drinking water or food and produce various syndromes. Nontuberculous mycobacteria (NTM) are increasingly being recognized to cause human infections, frequently in immunosuppressed individuals such as those who have organ transplants, individuals being treated for leukemia or cancer, and patients suffering from AIDS. The range of infections caused by NTM species is very broad and includes pulmonary infections (symptoms often indistinguishable from TB), cervical lymphadenitis, skin infections, bone and soft tissue infections, and nosocomial infections. An occupational disease in machinists, designated hypersensitivity pneumonitis (HP) has also been associated with NTM species (Mycobacterium immunogenumandMycobacterium chelonae) that have the ability to colonize metalworking fluids in occupational environments. Although this chapter focuses primarily on tuberculosis, nontuberculous mycobacteria that are associated with human disease are also discussed. It includes discussions on taxonomy, growth requirements, as well as the morphological characteristics, physiology, pathogenicity, and the metabolic activity of these organisms.
Aliphatic Nitro, Nitrate, and Nitrite Compounds
Authors: Ovesen Jerald L.
Published: August 2012

Although aliphatic nitro compounds, aliphatic nitrates, and aliphatic nitrites have several features in common (nitrogen–oxygen grouping, explosiveness, methemoglobin formation), there are significant differences in their toxic effects. Some of their attributes are summarized. The esters of nitric and nitrous acids, whose nitrogen is linked to carbon through oxygen, are very similar in their pharmacological effects. Both produce methemoglobinemia and vascular dilatation with hypotension and headache. These effects are transient. None of the series has appreciable irritant properties. Pathological changes occur in animals only after high levels of exposure and are generally nonspecific and reversible. The nitric acid esters of the monofunctional and lower polyfunctional alcohols are absorbed through the skin. Information is not available on the skin absorption of alkyl nitrites. Members of both groups are well absorbed from the mucous membranes and lungs. Heinz body formation has been observed with the nitrates but not with the nitrites.

Nitro compounds, like nitrates and nitrites, cause methemoglobinemia in animals. Heinz body formation parallels this activity within the series. Although some members are metabolized to nitrate and nitrite, there is no significant effect on blood pressure or respiration. As with the lower nitrates and nitrites, anesthetic symptoms are observed in animals during acute exposures, but these occur late. The prominent effect is irritation of the skin, mucous membranes, and respiratory tract. This is most marked with chlorinated nitroparaffins and nitroolefins. In addition to respiratory tract injury, cellular damage may be observed in the liver and kidneys. Skin absorption is negligible except for the nitroolefins.

The nitramines have entirely different activity. RDX is a convulsant for humans and animals. Skin absorption, irritation, vasodilatation, methemoglobin formation, and permanent pathological damage are either insignificant or absent after repeated doses.

Transient illness has been associated with the industrial use or manufacture of these materials, but fatalities and chronic intoxication have been uncommon. Some members of each group present extremely high fire and explosion hazards.
Aromatic Amino and Nitro–Amino Compounds and Their Halogenated Derivatives
Authors: Woo Yin‐Tak , Lai David Y.
Published: August 2012

Aromatic amines are organic compounds that contain at least one amino group attached directly to an aryl moiety. Aromatic amines represent one of the most important classes of industrial and environmental chemicals. Many aromatic amines have been shown to be potent carcinogens, mutagens, skin sensitizers, and/or hematotoxicants capable of inducing methemoglobinemia. Since the introduction of substituted anilines and naphthylamines as intermediates for the manufacture of azo dyes in the mid‐1800s, aromatic amines have found numerous uses in various industries. Substantial worker exposure to aromatic amines with subsequent induction of bladder cancer occurred before preventive measures were instituted. Beyond occupational exposure, humans may also be exposed to aromatic amines through environmental sources. At least three carcinogenic aromatic amines (4‐aminobiphenyl, 2‐naphthylamine, ando‐toluidine) have been detected in cigarette smoke. Many commonly used pharmaceuticals contain or are aromatic amines. Owing to their hazard potential, aromatic amines have been the subject of many biomonitoring studies, making them model compounds in molecular dosimetry and epidemiology studies. Since extensive information is available on the metabolic pathways and, to a lesser extent, the mechanism(s) of action, aromatic amines have also become targets for genetic polymorphism studies with ultimate goals of identifying susceptible subpopulations and designing of strategies for cancer prevention and intervention. The multifaceted interest in aromatic amines has continued to attract a tremendous amount of scientific studies and attention. Since the publication of the previous edition of Patty's on aromatic amines, many reviews and important research articles on aromatic amines and halogenated nitroaromatics have been published. In addition, a number of heterocyclic aromatic amines have attracted increasing attention as carcinogens of environmental significance. In this chapter, we present an overview of the aromatic amine class as a whole with emphasis on recent studies, followed by an updated description on individual chemicals grouped into eight subgroups of structurally related compounds.
Dibenzo‐p‐Dioxins: 2,3,7,8‐Tetrachlorodibenzo‐p‐Dioxin
Authors: Hee Shane Que
Published: August 2012

Chlorinated dibenzo‐para‐dioxins or dibenzo‐p‐dioxins (CDDs) are a class of compounds with 75 possible congeners. When the CDDs contain more than one chlorine they are termed polychlorinated dibenzo‐p‐dioxins (PCDDs). Most of the information is for 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (2,3,7,8‐TCDD), the most toxic congener. The bulk of the material in this chapter relates to this compound. The toxic PCDD congeners are substituted with chlorines in the 2,3,7, and 8 positions. The least toxic congeners are the monochlorinated PCDDs and octachlorodibenzo‐p‐dioxin [CAS RN3268‐87‐9], the fully chlorinated PCDD. PCDDs often are accompanied by the dibenzofuran analogs, the polychlorinated dibenzofurans (PCDFs), and the diphenyl ether analogs, the polychlorinated diphenyl ethers (PCDPEs). The cumulative toxicity of the toxic congeners of polychlorinated biphenyls (PCBs), PCDDs, PCDFs, and PCDPEs in a sample is expressed through the 2,3,7,8‐TCDD toxicity equivalent (TEQ) and toxicity equivalency factor (TEF) concepts because real‐life exposures are to mixtures of PCDDs, PCDFs, PCDEs, and PCBs rather than to 2,3,7,8‐TCDD alone.
Organic Chlorofluoro Hydrocarbons
Authors: Rusch George M.
Published: August 2012

The chlorofluorocarbons (CFCs) have been used as refrigerants for many years. Because of their low chemical reactivity, they typically have long atmospheric residence times, and as a consequence, are distributed globally. The widespread use of these chemicals has been associated with depletion in ozone layer. Most of the nations of the world drafted and signed an agreement calling for the phaseout of CFCs. Further developments were initiated on two types of “in‐kind” replacements. The first were the hydrochlorofluorocarbons (HCFCs) and the second were the hydrofluorocarbons (HFCs). These chemicals are treated as greenhouse warming gases. It has been found that many of these chemicals are not highly toxic. The most typical responses observed following overexposure are sensitization of the myocardium to the action of adrenalin and CNS depression related to the anesthetic properties of many of these chemicals. Studies have been designed to allow for the determination of no‐observed‐effect levels (NOEL), thresholds, and EC50s as median effect concentrations. The present chapter summarizes the properties, production, uses, toxic effects, environmental impact and guidelines of exposure of these chemicals.
Aliphatic Carboxylic Acids: Unsaturated
Authors: Szilagyi Maria
Published: August 2012

The alkenoic series of carboxylic acids are obtained from such natural sources as animal tallows and greases, and vegetable, coconut, palm, and marine oils. Several have also been produced synthetically from petroleum sources. They are frequently referred to as fatty acids (C6–C24) and have important commercial applications in plastics, coating materials, fungicides, food preservatives, lubricants, and perfumes. They have been used as softening agents for rubber and as pharmaceuticals in medicine and dentistry. Acids of this type are unstable and polymerize readily, hence offering important chemical and physical properties for use in producing esters, acid halides, acid amides, and acid anhydrides.

As a class, the unsaturated carboxylic acids have been subjected to an extensive battery of studies, including acute, short‐term, and chronic toxicity and carcinogenicity tests and reproductive and developmental toxicity and genotoxicity tests. Overall, these acids have a low level of mammalian toxicity, although they are strong skin and eye irritants in animal tests and are irritating to mucosal membranes in humans. For those acids for which adequate studies have been conducted, there is no evidence that they are reproductive or developmental toxicants or carcinogens. Mutagenicity and clastogenicity studies suggest that this group of acids is devoid of genotoxic activity. The biochemistry of many of these acids can be found in general textbooks. Rapid metabolism to other fatty acids may explain their general low degree of toxicity. The physical properties and acute toxicity of saturated monocarboxylic acids are provided.

Dietarytransfatty acids are associated with increased risk of cardiovascular disease and have been implicated in the incidence of obesity and type 2 diabetes mellitus.Transfatty acids from industrial sources (i.e., partially hydrogenated vegetable oil) have been associated with several chronic human diseases, especially coronary heart disease.
Aldehydes and Acetals
Authors: Borchers Michael T.
Published: August 2012

More than 300 aldehydes occur in foods, water, and air. Due to the electrophilicity of the carbonyl carbon, particularly when proximal to a carbon–carbon double bond, aldehydes react with thiols and amines to form protein–protein, DNA–protein, and DNA–DNA cross‐links. Despite their potential for causing cell damage, toxicological and exposure data for a large number of aldehydes are lacking. Inhalation and ingestion studies have demonstrated that a number of aldehydes are irritants and can induce tumors in animal models. Formaldehyde, which is a suspected carcinogen, is the most widely studied of these compounds. The physicochemical properties of saturated aldehydes are summarized. Toxicological and health effects are given.
Cold Stress: Effects on Performance and Health
Authors: Holmér Ingvar , Hassi Juhani , Ikäheimo Tiina M. , Jaakkola Jouni J. K.
Published: August 2012

The present chapter is intended to provide an overview of cold stress and strain not only on workers in cold workplaces, but also on people in general exposed to cold climate. Human adaptation to cold can be either acquired or inherited and occurs through acclimatization. The pattern of cold adaptation is dependent on the type (air, water) and intensity (continuous, intermittent) of the cold exposure. It has been reported that cold exposure and cooling can have profound effects on physical and cognitive performance. The majority of scientific reports related to health consequences of cold weather are on acute health changes. The study finds that total mortality among most populations is highest in winter and lowest in summer. Regulations or standards defining acceptable cold stress situations rely on one or a combination of approaches to control cold stress. Most prevalent national or international exposure guidelines have been provided comprehensively.
Heat Stress
Authors: Larrañaga Michael D. , Wang Qingsheng
Published: August 2012

This chapter's goal is to provide useful information about the way people respond to acute and chronic heat stress and heat strain, the man's physiological response to heat stress. The chapter provides detailed information about the physiological aspects of heat stress. It also presents some groundwork about biological control systems, how heat is produced and stored in the body, and how it is exchanged with the environment. This background is necessary to understand the many complex and interactive phenomena associated with heat stress and with the challenges of heat strain. It is important to recognize the uniqueness of heat as a form of energy to understand issues of heat stress and strain and to see its special role in human welfare. No other potentially endangering energy, for example, is produced by the body itself, none other is so essential for life, and none other is the thermodynamic destiny in entropy for all other forms of energy.
Recent Advances in Metal Oxide‐based Electrode Architecture Design for Electrochemical Energy Storage
Authors: Jiang Jian , Li Yuanyuan , Liu Jinping , Huang Xintang , Yuan Changzhou , Lou Xiong Wen (David)
Published: August 2012

Metal oxide nanostructures are promising electrode materials for lithium‐ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2–3 times higher than that of the carbon/graphite‐based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part “how to design superior electrode architectures”. In the article, we will review recent advances in strategies for advanced metal oxide‐based hybrid nanostructure design, with the focus on the binder‐free film/array electrodes. These binder‐free electrodes, with the integration of unique merits of each component, can provide larger electrochemically active surface area, faster electron transport and superior ion diffusion, thus leading to substantially improved cycling and rate performance. Several recently emerged concepts of using ordered nanostructure arrays, synergetic core‐shell structures, nanostructured current collectors, and flexible paper/textile electrodes will be highlighted, pointing out advantages and challenges where appropriate. Some future electrode design trends and directions are also discussed.
Prevalence rates of work organization characteristics among workers in the U.S.: Data from the 2010 National Health Interview Survey
Authors: Alterman Toni , Luckhaupt Sara E. , Dahlhamer James M. , Ward Brian W. , Calvert Geoffrey M.
Published: August 2012

Background

Surveillance is needed to capture work organization characteristics and to identify their trends.

Methods

Data from the 2010 National Health Interview Survey (NHIS) were used to calculate prevalence rates for four work organization characteristics (long work hours, non‐standard work arrangements, temporary positions, and alternative shifts) overall, and by demographic characteristics, and industry and occupation of current/recent employment.

Results

Data were available for 27,157 adults, of which 65% were current/recent workers. Among adults who worked in the past 12 months, 18.7% worked 48 hr or more per week, 7.2% worked 60 hr or more per week, 18.7% had non‐standard work arrangements, 7.2% were in temporary positions, and 28.7% worked an alternative shift.

Conclusions

Prevalence rates of work organization characteristics are provided. These national estimates can be used to help occupational health professionals and employers to identify emerging occupational safety and health risks, allow researchers to examine associations with health, and use the data for benchmarking. Am. J. Ind. Med. 56:647–659, 2013. © 2012 Wiley Periodicals, Inc.
Drug‐Resistant Human Staphylococcus Aureus in Sanctuary Apes Pose a Threat to Endangered Wild Ape Populations
Authors: SCHAUMBURG FRIEDER , MUGISHA LAWRENCE , PECK BRUCE , BECKER KARSTEN , GILLESPIE THOMAS R. , PETERS GEORG , LEENDERTZ FABIAN H.
Published: August 2012

Reintroduction of sanctuary apes to natural habitat is considered an important tool for conservation; however, reintroduction has the potential to endanger resident wild apes through the introduction of human pathogens. We found a high prevalence of drug‐resistant, human‐associated lineages of Staphylococcus aureus in sanctuary chimpanzees (Pan troglodytes) from Zambia and Uganda. This pathogen is associated with skin and soft tissue diseases and severe invasive infections (i.e. pneumonia and septicemia). Colonization by this bacterium is difficult to clear due to frequent recolonization. In addition to its pathogenic potential, human‐related S. aureus can serve as an indicator organism for the transmission of other potential pathogens like pneumococci or mycobacteria. Plans to reintroduce sanctuary apes should be reevaluated in light of the high risk of introducing human‐adapted S. aureus into wild ape populations where treatment is impossible. Am. J. Primatol. 74:1071‐1075, 2012. © 2012 Wiley Periodicals, Inc.
Properties of recycled polycaprolactone‐based thermoplastic polyurethane filled with montmorillonites
Authors: Žukienė Kristina , Jankauskaitė Virginija , Betingytė Vitalija , Baltušnikas Arūnas
Published: August 2012

The properties of recycled low temperature biodegradable polycaprolactone‐based thermoplastic polyurethane (rTPU), filled with different types of organically modified montmorillonite (MMT) prepared by two‐roll milling, were studied. The dependence of rTPU properties on the mastication time and clays content was determined by various structural and physical testing methods. Results show that the melt flow and mechanical properties of rTPU deteriorate with increasing of mastication time, but thermal properties were affected only slightly. rTPU/MMT composites show exfoliated or intercalated structures depending on the nature of organic modifier of clay. MMT reduces slightly rTPU tensile and melt flow properties, but accelerates hydrolytic degradation process. During degradation the weight loss and polydispersity increase significantly in the presence of MMT, but it does not accelerate crystallinity changes. The degradation of rTPU composites with higher hydrophilicity organoclays proceeds faster than that with hydrophobic ones due to the relatively higher interaction with polymer matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Accumulation of Vitamin A in the Hepatic Stellate Cell of Arctic Top Predators
Authors: Senoo Haruki , Imai Katsuyuki , Mezaki Yoshihiro , Miura Mitsutaka , Morii Mayako , Fujiwara Mutsunori , Blomhoff Rune
Published: August 2012

We performed a systematic characterization of the hepatic vitamin A storage in mammals and birds of the Svalbard archipelago and Greenland. The liver of top predators, including polar bear, arctic fox, bearded seal, and glaucous gull, contained about 10–20 times more vitamin A than the liver of all other arctic animals studied, as well as their genetically related continental top predators. The values are also high compared to normal human and experimental animals like mouse and rat. This massive amount of hepatic vitamin A was located in large autofluorescent lipid droplets in hepatic stellate cells (HSCs; also called vitamin A‐storing cells, lipocytes, interstitial cells, fat‐storing cells, or Ito cells). The droplets made up most of the cells' cytoplasm. The development of such an efficient vitamin A‐storing mechanism in HSCs may have contributed to the survival of top predators in the extreme environment of the arctic. These animals demonstrated no signs of hypervitaminosis A. We suggest that HSCs have capacity to take‐up and store large amounts of vitamin A, which may play a pivotal role in maintenance of the food web, food chain, biodiversity, and eventually ecology of the arctic. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Trimethyl‐4‐oxo‐4,5,6,7‐tetrahydroindazole‐1‐acetic Acid: A New Lead Compound with Selective COX‐2 Inhibitory Activity
Authors: Abdel‐Rahman Hamdy M. , Ozadali Keriman
Published: August 2012

A novel series of 3,6,6‐trimethyl‐4‐oxo‐4,5,6,7‐tetrahydroindazole‐1‐acetic acid derivatives was designed and synthesized by a new one‐step pathway. Structure elucidation of the synthesized compounds was confirmed by various spectral and elemental analyses. The prepared compounds were evaluated for their ability to inhibit cyclooxygenase‐2 (COX‐2) and cyclooxygenase‐1 (COX‐1) enzymes in vitro. Among the synthesized compounds, the 2‐(3,6,6‐trimethyl‐4‐oxo‐4,5,6,7‐tetrahydroindazol‐1‐yl)acetic acid 4 emerged as the most potent COX‐2 inhibitor (IC50 value: 150 nM) with the highest selectivity index (COX‐1/COX‐2 inhibition ratio: 570.6). Docking studies of compound 4 in the active site of COX‐2 recognized its potential binding mode to the enzyme. Based on the preliminary results, compound 4 was considered as a lead compound for further optimization.
Keratinocyte galvanotaxis in combined DC and AC electric fields supports an electromechanical transduction sensing mechanism
Authors: Hart Francis X. , Laird Mhairi , Riding Aimie , Pullar Christine E.
Published: August 2012

Sedentary keratinocytes at the edge of a skin wound migrate into the wound, guided by the generation of an endogenous electric field (EF) generated by the collapse of the transepithelial potential. The center of the wound quickly becomes more negative than the surrounding tissue and remains the cathode of the endogenous EF until the wound is completely re‐epithelialized. This endogenous guidance cue can be studied in vitro. When placed in a direct current (DC) EF of physiological strength, 100 V/m, keratinocytes migrate directionally toward the cathode in a process known as galvanotaxis. Although a number of membrane‐bound (e.g., epidermal growth factor receptor (EGFR), integrins) and cytosolic proteins (cAMP, ERK, PI3K) are known to play a role in the downstream signaling mechanisms underpinning galvanotaxis, the initial sensing mechanism for this response is not understood. To investigate the EF sensor, we studied the migration of keratinocytes in a DC EF of 100 V/m, alternating current (AC) EFs of 40 V/m at either 1.6 or 160 Hz, and combinations of DC and AC EFs. In the AC EFs alone, keratinocytes migrated randomly. The 1.6 Hz AC EF combined with the DC EF suppressed the direction of migration but had no effect on speed. In contrast, the 160 Hz AC EF combined with the DC EF did not affect the direction of migration but increased the migration speed compared to the DC EF alone. These results can be understood in terms of an electromechanical transduction model, but not an electrodiffusion/osmosis or a voltage‐gated channel model. Bioelectromagnetics 34:85–94, 2013. © 2012 Wiley Periodicals, Inc.
Review pathway analysis for peptide‐mediated electronic coupling in the super‐exchange mechanism of ET and EET
Authors: Kawatsu Tsutomu
Published: August 2012

Electron and excitation energy transfers (ET and EET) have an important role in biological energy‐exchange processes. Proteins are an inhomogeneous and anisotropic medium for ET and EET. The protein structure influences electronic coupling, an important factor for ET and EET. The structure factor may be predicted by obtaining information about the tunneling pathways. The present paper mainly focuses on tunneling pathway analysis using the tunneling current (flux) of the electron or configuration density. The tunneling pathways for ET and singlet EET through peptides are introduced using tunneling current (flux) analysis. These tunneling pathways differ greatly between ET and singlet EET. This paper also reviews both the theoretical background and other methods for determining electronic tunneling pathways. These pathways are related to the effect of protein coordinates on the electronic coupling between the initial and final states of the ET and EET. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 100: 100–113, 2013.
Spectroscopy of the Simplest Criegee Intermediate CH2OO: Simulation of the First Bands in Its Electronic and Photoelectron Spectra
Authors: Lee Edmond P. F. , Mok Daniel K. W. , Shallcross Dudley E. , Percival Carl J. , Osborn David L. , Taatjes Craig A. , Dyke John M.
Published: August 2012

CH2OO, the simplest Criegee intermediate, and ozone are isoelectronic. They both play very important roles in atmospheric chemistry. Whilst extensive experimental studies have been made on ozone, there were no direct gas‐phase studies on CH2OO until very recently when its photoionization spectrum was recorded and kinetics studies were made of some reactions of CH2OO with a number of molecules of atmospheric importance, using photoionization mass spectrometry to monitor CH2OO. In order to encourage more direct studies on CH2OO and other Criegee intermediates, the electronic and photoelectron spectra of CH2OO have been simulated using high level electronic structure calculations and Franck–Condon factor calculations, and the results are presented here. Adiabatic and vertical excitation energies of CH2OO were calculated with TDDFT, EOM‐CCSD, and CASSCF methods. Also, DFT, QCISD and CASSCF calculations were performed on neutral and low‐lying ionic states, with single energy calculations being carried out at higher levels to obtain more reliable ionization energies. The results show that the most intense band in the electronic spectrum of CH2OO corresponds to the${{\rm{\tilde B}}}$1A′ ←${{\rm{\tilde X}}}$1A′ absorption. It is a broad band in the region 250–450 nm showing extensive structure in vibrational modes involving O–O stretching and C‐O‐O bending. Evidence is presented to show that the electronic absorption spectrum of CH2OO has probably been recorded in earlier work, albeit at low resolution. We suggest that CH2OO was prepared in this earlier work from the reaction of CH2I with O2and that the assignment of the observed spectrum solely to CH2IOO is incorrect. The low ionization energy region of the photoelectron spectrum of CH2OO consists of two overlapping vibrationally structured bands corresponding to one‐electron ionizations from the highest two occupied molecular orbitals of the neutral molecule. In each case, the adiabatic component is the most intense and the adiabatic ionization energies of these bands are expected to be very close, at 9.971 and 9.974 eV at the highest level of theory used.
Preparation of Photocatalytic Au–Ag2Te Nanomaterials
Authors: Lin Zong‐Hong , Shih Zih‐Yu , Roy Prathik , Chang Huan‐Tsung
Published: August 2012

A facile approach has been developed for the preparation of various morphologies of Au–Ag2Te nanomaterials (NMs) that exhibit strong photocatalytic activity. Te NMs (nanowires, nanopencils, and nanorice) were prepared from TeO2 in the presence of various concentrations (16, 8, and 4 M) of a reducing agent (N2H4) at different temperatures (25 and 60 °C). These three Te NMs were then used to prepare Au–Ag2Te NMs by spontaneous redox reactions with Au3+ and Ag+ ions sequentially. The Au–Ag2Te nanopencils exhibit the highest activity toward degradation of methylene blue and formation of active hydroxyl radicals on solar irradiation, mainly because they absorb light in the visible region most strongly. All three differently shaped Au–Ag2Te NMs (10 μg mL−1) provide a death rate of Escherichia coli greater than 80 % within 60 min, which is higher than that of 51 % for commercial TiO2 nanoparticles (100 μg mL−1). Under light irradiation, the Au NPs in Au–Ag2Te NMs enhance the overall photo‐oxidation ability of Ag2Te NMs through faster charge separation because of good contact between Ag2Te and Au segments. With high antibacterial activity and low toxicity toward normal cells, the Au–Ag2Te NMs hold great potential for use as efficient antibacterial agents.
Key Role of Intramolecular Metal Chelation and Hydrogen Bonding in the Cobalt‐Mediated Radical Polymerization of N‐Vinyl Amides
Authors: Debuigne Antoine , Morin Aurélie N. , Kermagoret Anthony , Piette Yasmine , Detrembleur Christophe , Jérôme Christine , Poli Rinaldo
Published: August 2012

This work reveals the preponderance of an intramolecular metal chelation phenomenon in a controlled radical polymerization system involving the reversible trapping of the radical chains by a cobalt complex bis(acetylacetonato)cobalt(II). The cobalt‐mediated radical polymerization (CMRP) of a series of N‐vinyl amides was considered with the aim of studying the effect of the cobalt chelation by the amide moiety of the last monomer unit of the chain. The latter reinforces the cobaltpolymer bond in the order N‐vinylpyrrolidone<N‐vinyl caprolactam<N‐methyl‐N‐vinyl acetamide, and is responsible for the optimal control of the polymerizations observed for the last two monomers. Such a double linkage between the controlling agent and the polymer, through a covalent bond and a dative bond, is unique in the field of controlled radical polymerization and represents a powerful opportunity to fine tune the equilibrium between latent and free radicals. Possible hydrogen bond formation is also taken into account in the case of N‐vinyl acetamide and N‐vinyl formamide. These results are essential for understanding the factors influencing CoC bond strength in general, and the CMRP mechanism in particular, but also for developing a powerful platform for the synthesis of new precision poly(N‐vinyl amide) materials, which are an important class of polymers that sustain numerous applications today.
Coordination‐Like Chemistry of Phosphinidenes by Phosphanes
Authors: Protasiewicz John D.
Published: August 2012

This microreview examines chemistry of phosphane adducts of phosphinidenes (phosphanylidene‐σ4‐phosphoranes, RP=PR3) whose formation or reactions are reminiscent of the coordination chemistry of phosphane ligands in transition metal complexes.
Effects of gemfibrozil on lipid metabolism, steroidogenesis, and reproduction in the fathead minnow (Pimephales promelas)
Authors: Skolness Sarah Y. , Durhan Elizabeth J. , Jensen Kathleen M. , Kahl Michael D. , Makynen Elizabeth A. , Villeneuve Daniel L. , Ankley Gerald T.
Published: August 2012

Fibrates are a class of pharmaceuticals that indirectly modulate cholesterol biosynthesis through effects on peroxisome proliferator-activated receptors. Gemfibrozil is a fibrate that has been detected in wastewater treatment plant influents, effluents, and drinking water. The objective of the present study was to assess the potential physiological and reproductive impacts of gemfibrozil on fathead minnows (Pimephales promelas). Fish were exposed to gemfibrozil in two different studies. The first was a short-term test with water concentrations of 0, 15, and 600 µg gemfibrozil/L, sampling after 2 or 8 d of exposure. Plasma cholesterol concentrations were significantly reduced in males exposed to 600 µg gemfibrozil/L for 8 d. In addition, expression of several hepatic genes important to lipid metabolism was altered, suggesting that gemfibrozil does affect lipid metabolism in fish. A 21-d study was conducted to investigate further the effects on lipid metabolism and steroidogenesis as well as to assess potential impacts of gemfibrozil on reproduction. Fish were exposed to water concentrations of 0, 1.5, 15, 600, and 1,500 µg gemfibrozil/L. Exposure to 1,500 µg gemfibrozil/L caused a modest, but not significant, reduction in fecundity. However, gemfibrozil had no consistent effect on plasma cholesterol, triglycerides, or sex steroids after 21 d of exposure. The present study showed no evidence for significant physiological or reproductive impacts of gemfibrozil at an environmentally relevant concentration of 1.5 µg/L. Environ. Toxicol. Chem. 2012; 31: 2615–2624. © 2012 SETAC