Measurement properties of the Shiftwork Survey and Standard Shiftwork Index

The Shiftwork Survey (SS) was introduced, along with the Standard Shiftwork Index (SSI), to provide a set of standardized self-report measures to be used in shiftwork research. However, beyond the initial assessment, no attempt has been made to examine the measurement properties of these scales in an independent sample of shiftworkers. Our goal, therefore, was to examine the measurement properties of these scales in an industrial sample of primarily male shiftworkers (N = 370). We found that all scales had acceptable reliabilities (alphas). The confirmatory factor analyses revealed that the chronic fatigue, coping, job satisfaction, and sleep scales are the weakest psychometrically, and the anxiety, personality (extraversion, neuroticism), general health, and physical health scales are the strongest psychometrically. Using item response theory analyses, we found that the scales overall are generally adequate measures of their underlying constructs, although many items should be altered or omitted. Our results, however, are limited by reliance on a single sample.     

Predicting shiftwork-related outcomes: shiftwork locus of control and circadian type

This research discusses the use and viability of the shiftwork locus of control construct alongside circadian type measures as a potential predictor of shiftwork-related outcomes. The shiftwork locus of control (SHLOC) scale, measures of circadian type and shiftwork-related outcome measures were completed by 100 shiftworkers on two occasions separated by seven months. The SHLOC scale measures shiftworkers' generalised beliefs about the levels of personal control they perceive in relation to four major functional domains commonly associated with shiftwork-related disruption. These domains include: sleep, social, health and work problems. The results of multivariate regression analysis showed the SHLOC scale to be predictive of the experience of shiftwork-related sleep and social-life problems while the circadian type measures were predictive of alertness at 7 months. The results suggest that a constellation of personality factors may be an important influence on an individual's tolerance to shiftwork.     

Acidosis Activation of the Proton-Sensing GPR4 Receptor Stimulates Vascular Endothelial Cell Inflammatory Responses Revealed by Transcriptome Analysis

Acidic tissue microenvironment commonly exists in inflammatory diseases, tumors, ischemic organs, sickle cell disease, and many other pathological conditions due to hypoxia, glycolytic cell metabolism and deficient blood perfusion. However, the molecular mechanisms by which cells sense and respond to the acidic microenvironment are not well understood. GPR4 is a proton-sensing receptor expressed in endothelial cells and other cell types. The receptor is fully activated by acidic extracellular pH but exhibits lesser activity at the physiological pH 7.4 and minimal activity at more alkaline pH. To delineate the function and signaling pathways of GPR4 activation by acidosis in endothelial cells, we compared the global gene expression of the acidosis response in primary human umbilical vein endothelial cells (HUVEC) with varying level of GPR4. The results demonstrated that acidosis activation of GPR4 in HUVEC substantially increased the expression of a number of inflammatory genes such as chemokines, cytokines, adhesion molecules, NF-κB pathway genes, and prostaglandin-endoperoxidase synthase 2 (PTGS2 or COX-2) and stress response genes such as ATF3 and DDIT3 (CHOP). Similar GPR4-mediated acidosis induction of the inflammatory genes was also noted in other types of endothelial cells including human lung microvascular endothelial cells and pulmonary artery endothelial cells. Further analyses indicated that the NF-κB pathway was important for the acidosis/GPR4-induced inflammatory gene expression. Moreover, acidosis activation of GPR4 increased the adhesion of HUVEC to U937 monocytic cells under a flow condition. Importantly, treatment with a recently identified GPR4 antagonist significantly reduced the acidosis/GPR4-mediated endothelial cell inflammatory response. Taken together, these results show that activation of GPR4 by acidosis stimulates the expression of a wide range of inflammatory genes in endothelial cells. Such inflammatory response can be suppressed by GPR4 small molecule inhibitors and hold potential therapeutic value.     

Does fear of immigration authorities deter tuberculosis patients from seeking care?

Physician groups are concerned that legislation requiring physicians to report illegal immigrants to immigration authorities will delay curative care. In particular, patients with tuberculosis may delay seeking care for infectious symptoms and spread the disease. We surveyed 313 consecutive patients with active tuberculosis from 95 different facilities to examine the relationship of immigration-related variables, symptoms, and delay in seeking care. Most patients (71%) sought care for symptoms rather than as a result of the efforts of public health personnel to screen high-risk groups or to trace contacts of infectious persons. At least 20% of respondents lacked legal documents allowing them to reside in the United States. Few (6%) feared that going to a physician might lead to trouble with immigration authorities. Those who did were almost 4 times as likely to delay seeking care for more than 2 months, a period of time likely to result in disease transmission. Patients potentially exposed an average of 10 domestic and workplace contacts during the course of the delay. Any legislation that increases undocumented immigrants'' fear that health care professionals will report them to immigration authorities may exacerbate the current tuberculosis epidemic.     

Protection against a fungal pathogen conferred by the aphid facultative endosymbionts Rickettsia and Spiroplasma is expressed in multiple host genotypes and species and is not influenced by co‐infection with another symbiont

Many insects harbour facultative endosymbiotic bacteria, often more than one type at a time. These symbionts can have major effects on their hosts' biology, which may be modulated by the presence of other symbiont species and by the host's genetic background. We investigated these effects by transferring two sets of facultative endosymbionts (one Hamiltonella and Rickettsia, the other Hamiltonella and Spiroplasma) from naturally double‐infected pea aphid hosts into five novel host genotypes of two aphid species. The symbionts were transferred either together or separately. We then measured aphid fecundity and susceptibility to an entomopathogenic fungus. The pathogen‐protective phenotype conferred by the symbionts Rickettsia and Spiroplasma varied among host genotypes, but was not influenced by co‐infection with Hamiltonella. Fecundity varied across single and double infections and between symbiont types, aphid genotypes and species. Some host genotypes benefit from harbouring more than one symbiont type.     

Unrelated facultative endosymbionts protect aphids against a fungal pathogen

The importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. In the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. Here we show that protection against this entomopathogen, Pandora neoaphidis, can be conferred by strains of four distantly related symbionts (in the genera Regiella, Rickettsia, Rickettsiella and Spiroplasma). They reduce mortality and also decrease fungal sporulation on dead aphids which may help protect nearby genetically identical insects. Pea aphids thus obtain protection from natural enemies through association with a wider range of microbial associates than has previously been thought. Providing resistance against natural enemies appears to be a particularly common way for facultative endosymbionts to increase in frequency within host populations.     

LÉVI-STRAUSS AND THE POLITICAL: THE ELEMENTARY STRUCTURES OF KINSHIP AND THE RESOLUTION OF RELATIONS BETWEEN INDIGENOUS PEOPLES AND SETTLER STATES

This article addresses the contribution of Lévi-Strauss's The elementary structures of kinship to resolving political relations between indigenous peoples and the settler states. To this end, it explores his discussion of the origins of society within the context of Enlightenment-inspired political thought and concludes that he provides a unique, counter-hegemonic alternative to conventional narratives. It then shows how this argument thwarts the presumption in Canadian jurisprudence that indigenous peoples were automatically incorporated into the state through European settlement, and fosters an understanding that a relationship based on the concept of 'Treaty' as understood in indigenous political thought promotes a political relationship that affirms the integrity of all parties.     

Modelling lake cyanobacterial blooms: Disentangling the climate‐driven impacts of changing mixed depth and water temperature

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Epistatic interactions: how strong in disease and evolution?

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