A Model of Attitudes toward the Acceptance of Mobile Phone Use in Public Places

Since the first commercial launch of cellular telecoms by NET in Tokyo Japan in 1979 and the launch of the NMT system in Denmark, Finland, Norway and Sweden in 1981, the mobile phone has undergone continual incremental innovation for changing market needs. This study investigates the factors affecting the attitudes towards the social acceptance of mobile phones in public places and how this attitude affects its usage. Theories on innovation and technology acceptance were reviewed, and studies relating demographic factors to technology acceptance were examined. A model was proposed relating the usage frequency and attitudes towards acceptance of mobile phone in public places to demographic factors, such as country, age, education, gender, and work status. A survey was conducted among mobile phone users, and the sample consisted of 1079 respondents in the United States, France, Italy, Turkey, and Finland. A structural equation model was developed to analyze the survey data. Results of the analysis indicate that the attitudes about mobile phone use in public places depend on country, and age factors. This attitude in turn significantly affects the usage frequency of mobile phones. In addition, usage frequency also is affected by gender and work status. Implications of the findings for both academicians and practitioners are discussedAttitudes about Mobile Phone Use, Simultaneous Relationships, Demographic Factors, Mobile Phone Voice Messaging, Mobile Phone Text Messaging

Active Site Structures of CYP11A1 in the Presence of Its Physiological Substrates and Alterations upon Binding of Adrenodoxin

The rate-limiting step in the steroid synthesis pathway is catalyzed by CYP11A1 through three sequential reactions. The first two steps involve hydroxylations at positions 22 and 20, generating 20(R),22(R)-dihydroxycholesterol (20R,22R-DiOHCH), with the third stage leading to a C20–C22 bond cleavage, forming pregnenolone. This work provides detailed information about the active site structure of CYP11A1 in the resting state and substrate-bound ferric forms as well as the CO-ligated adducts. In addition, high-quality resonance Raman spectra are reported for the dioxygen complexes, providing new insight into the status of Fe–O–O fragments encountered during the enzymatic cycle. Results show that the three natural substrates of CYP11A1 have quite different effects on the active site structure, including variations of spin state populations, reorientations of heme peripheral groups, and, most importantly, substrate-mediated distortions of Fe–CO and Fe–O2 fragments, as revealed by telltale shifts of the observed vibrational modes. Specifically, the vibrational mode patterns observed for the Fe–O–O fragments with the first and third substrates are consistent with H-bonding interactions with the terminal oxygen, a structural feature that tends to promote O–O bond cleavage to form the Compound I intermediate. Furthermore, such spectral data are acquired for complexes with the natural redox partner, adrenodoxin (Adx), revealing protein–protein-induced active site structural perturbations. While this work shows that Adx has an only weak effect on ferric and ferrous CO states, it has a relatively stronger impact on the Fe–O–O fragments of the functionally relevant oxy complexes

End-organ resistance to growth hormone and IGF-I in epiphyseal chondrocytes of rats with chronic renal failure

End-organ resistance to growth hormone and IGF-I in epiphyseal chondrocytes of rats with chronic renal failure. We tested the hypothesis that there is direct end-organ resistance to growth hormone (GH) and IGF-I in chronic renal failure (CRF) independent of circulating inhibitors. Male Sprague-Dawley rats underwent 5/6 nephrectomy and were pair-fed with weight matched (100 g) sham operated controls for two weeks. Rats with CRF had significantly higher serum creatinine and blood urea nitrogen (P < 0.01 in both cases) and gained significantly less weight and length (P < 0.01 in both cases) compared with controls. Epiphyseal chondrocytes were grown in 10% fetal calf serum (FCS). Both CRF cells and control cells maintained chondrogenic phenotypes, and showed immunohistochemical staining with antibodies to collagen II and proteoglycan (aggrecan). Distribution of the cell subpopulations according to cell size (by flow cytometry) and alkaline phosphatase activity of CRF and control chondrocyte cultures were not different. Growth responses of CRF chondrocytes were reduced (P < 0.01) compared with control chondrocytes when grown in 10% FCS and 10% normal rat serum. Under serum free conditions, growth responses of CRF chondrocytes were reduced to GH and IGF-I at concentrations of 10, 30 and 100 ng/ml, and to insulin at 100, 300 and 1,000 ng/ml compared with controls cells (P < 0.01). To show that this resistance is specific for the GH/IGF system, growth responses to fibroblast growth factor and transforming growth factor β1 were studied and showed no difference between CRF and control cells. Thus, the present study provides direct evidence of specific end-organ resistance to GH, IGF-I in CRF chondrocytes in the absence of circulating factors

Is ghrelin a biomarker for mortality in end-stage renal disease?

Ghrelin is involved in the pathogenesis of protein-energy wasting (PEW), inflammation, and cardiovascular complications in end-stage renal disease (ESRD). Plasma ghrelin may prove to be a powerful biomarker of mortality in ESRD but should be considered in the context of assay specificity, other weight-regulating hormones, nutritional status, systemic inflammation, and cardiovascular risk factors. ESRD patients with PEW, systemic inflammation, and low ghrelin and high leptin concentrations have the highest mortality risk and may benefit the most from ghrelin therapy

Ghrelin in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) often exhibit symptoms of anorexia and cachexia, which are associated with decreased quality of life and increased mortality. Chronic inflammation may be an important mechanism for the development of anorexia, cachexia, renal osteodystrophy, and increased cardiovascular risk in CKD. Ghrelin is a gastric hormone. The biological effects of ghrelin are mediated through the growth hormone secretagogue receptor (GHSR). The salutary effects of ghrelin on food intake and meal appreciation suggest that ghrelin could be an effective treatment for anorexic CKD patients. In addition to its appetite-stimulating effects, ghrelin has been shown to possess anti-inflammatory properties. The known metabolic effects of ghrelin and the potential implications in CKD will be discussed in this review. The strength, shortcomings, and unanswered questions related to ghrelin treatment in CKD will be addressed

Mobile Phone Use in Social Settings: A Multinational Study

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Valley Dynamics of Excitons in Monolayer Dichalcogenides

Monolayer transition-metal dichalcogenides (TMDCs) have recently emerged as possible candidates for valleytronic applications, as the spin and valley pseudospin are directly coupled and stabilized by a large spin splitting. In these semiconducting materials, optically excited electron-hole pairs form tightly Coulomb-bound excitons with large binding energies. The selection rules for excitonic transitions allow for direct optical generation of a valley-polarized exciton population using resonant excitation. Here, we investigate the exciton valley dynamics in monolayers of three different TMDCs by means of time-resolved Kerr rotation at low temperatures. We observe pronounced differences in the valley dynamics of tungsten- and molybdenum-based TMDCs, which are directly related to the opposite order of the conduction-band spin splitting in these materials

Opportunistic Screening in General Practice for Chlamydia Trachomatis in Young Men

Study Objective: There is little information available regarding the prevalence of Chlamydia Trachomatis in young men in the general population. The community based rate of infection is estimated to be 4.6%, but this is thought to reflect an over-representation of high-risk groups. The aims of this study were to1) estimate the rate of Chlamydia infection in young men attending general practitioners in the Perth metropolitan area, 2) assess behavioural factors associated having the disease and 3) assess GP management of patients testing positive. Methodology: Sexually active men (15-29 years) were recruited from 8 general practices in Perth, Western Australia. Participants were required to complete a questionnaire concerning their sexual orientation, history, behaviours and genital symptoms and provide a urine sample for PCR testing for Chlamydia. If a participant returned a positive PCR result, the treating doctor was contacted by a researcher 2 weeks following the test to assess patient follow up. Results: 401 men were recruited. 373 had urine results available. Of these 3.8% (95% CI, 2.1-6.2) returned a positive PCR result for Chlamydia Trachomatis. There were no remarkable differences between the sexual practices and behaviours of positive and negative participants, although we cannot exclude sampling bias given the small number of positive participants. All patients were followed up by their treating doctor once results were received. Despite the small number of positive participants, there was little relationship between self reported sexual behaviour or symptoms and incidence of Chlamydia in young men. Details of these findings will be provided at presentation. Conclusion: Given the asymptomatic nature, it may be appropriate to offer screening for at risk individuals, thereby moving towards curbing the increasing infection rate for this disease

AP-1 as a Regulator of MMP-13 in the Stromal Cell of Giant Cell Tumor of Bone

Matrix-metalloproteinase-13 (MMP-13) has been shown to be an important protease in inflammatory and neoplastic conditions of the skeletal system. In particular, the stromal cells of giant cell tumor of bone (GCT) express very high levels of MMP-13 in response to the cytokine-rich environment of the tumor. We have previously shown that MMP-13 expression in these cells is regulated, at least in part, by the RUNX2 transcription factor. In the current study, we identify the expression of the c-Fos and c-Jun elements of the AP-1 transcription factor in these cells by protein screening assays and real-time PCR. We then used siRNA gene knockdown to determine that these elements, in particular c-Jun, are upstream regulators of MMP-13 expression and activity in GCT stromal cells. We conclude that there was no synergy found between RUNX2 and AP-1 in the regulation of the MMP13 expression and that these transcription factors may be independently regulated in these cells