An investigation of the chlorophylls of selected prasinophyte algae.

Introduction: Chlorophyll a is the prevalent light-collecting pigment in eukaryotic, photosynthetic organisms. Several different chlorophylls exist in nature, but all autotrophic plants contain chlorophyll a (Bogorad, 1976). The majority of these chlorophyll a molecules function to absorb light and channel the excitation energy to photochemical sites in reaction centers. Chlorophylls b, c, d, and e, carotenoid pigments and phycobiliproteins are organized into antenna systems which absorb light maximally at different wavelengths. This design permits the visible light spectrum to be exploited (Foyer, 1984) for energy by different photosynthetic organisms. Chlorophyll b is present in higher plants, Chlorophyta, Prasinophyceae, and Euglenophyta; chlorophyll c is found in some members of Cryptophyceae, Dinophyceae, Rhaphidophyceae, Chrysophyceae, Haptophyceae, Bacillariophyceae, Xanthophyceae, and Phaeophyceae; chlorophyll d is found in some Florideophyceae in the Rhodophyta; and chlorophyll e has been found in feral populations of two members of Xanthophyceae. Chlorophyll e is believed to be a breakdown product of chlorophyll c (Meeks, 1974). Additional forms of chlorophyll, the bacteriochlorophylls, are found in bacteria other than the cyanobacteria (Holt, 1965

The Papers of Thomas A. Edison

This richly illustrated volume explores Edison’s inventive and personal pursuits from 1885 to 1887.Two decades after the American Civil War, no name was more closely associated with the nation’s inventive and entrepreneurial spirit than that of Thomas Edison. The restless changes of those years were reflected in the life of America’s foremost inventor. Having cemented his reputation with his electric lighting system, Edison had decided to withdraw partially from that field. At the start of 1885, newly widowed at mid-life with three young children, he launched into a series of personal and professional migrations, setting in motion chains of events that would influence his work and fundamentally reshape his life. Edison’s inventive activities took off in new directions, flowing between practical projects (such as wireless and high-capacity telegraph systems) and futuristic ones (exploring forms of electromagnetic energy and the convertibility of one to another). Inside of two years, he would travel widely, marry the daughter of a prominent industrialist and religious educator, leave New York City for a grand home in a sylvan suburb, and construct a winter laboratory and second home in Florida. Edison’s family and interior life are remarkably visible at this moment; his papers include the only known diary in which he recorded personal thoughts and events. By 1887, the familiar rhythms of his life began to reassert themselves in his new settings; the family faded from view as he planned, built, and occupied a New Jersey laboratory complex befitting his status. The eighth volume of the series, New Beginnings includes 358 documents (chosen from among thousands) that are the most revealing and representative of Edison’s work, life, and place in American culture in these years. Illustrated with hundreds of Edison’s drawings, these documents are further illuminated by meticulous research on a wide range of sources, including the most recently digitized newspapers and journals of the day

Eating Disorders Among a Community‐Based Sample of Chilean Female Adolescents

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88044/1/jora733.pd

Asexuality: Classification and characterization

This is a post-print version of the article. The official published version can be obtaineed at the link below.The term “asexual” has been defined in many different ways and asexuality has received very little research attention. In a small qualitative study (N = 4), individuals who self-identified as asexual were interviewed to help formulate hypotheses for a larger study. The second larger study was an online survey drawn from a convenience sample designed to better characterize asexuality and to test predictors of asexual identity. A convenience sample of 1,146 individuals (N = 41 self-identified asexual) completed online questionnaires assessing sexual history, sexual inhibition and excitation, sexual desire, and an open-response questionnaire concerning asexual identity. Asexuals reported significantly less desire for sex with a partner, lower sexual arousability, and lower sexual excitation but did not differ consistently from non-asexuals in their sexual inhibition scores or their desire to masturbate. Content analyses supported the idea that low sexual desire is the primary feature predicting asexual identity

Knowledge of ghostwriting and financial conflicts-of-interest reduces the perceived credibility of biomedical research

<p>Abstract</p> <p>Background</p> <p>While the impact of conflicts-of-interest (COI) is of increasing concern in academic medicine, there is little research on the reaction of practicing clinicians to the disclosure of such conflicts. We developed two research vignettes presenting a fictional antidepressant medication study, one in which the principal investigator had no COI and another in which there were multiple COI disclosed. We confirmed the face validity of the COI vignette through consultation with experts. Hospital-based clinicians were randomly assigned to read one of these two vignettes and then administered a credibility scale.</p> <p>Findings</p> <p>Perceived credibility ratings were much lower in the COI group, with a difference of 11.00 points (31.42%) on the credibility scale total as calculated through the Mann-Whitney U test (95% CI = 6.99 - 15.00, <it>p </it>< .001). Clinicians in the COI group were also less likely to recommend the antidepressant medication discussed in the vignette (Odds Ratio = 0.163, 95% CI = .03 = 0.875).</p> <p>Conclusions</p> <p>In this study, increased disclosure of COI resulted in lower credibility ratings.</p

Gender, school and academic year differences among Spanish university students at high-risk for developing an eating disorder: An epidemiologic study

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the magnitude of the university population at high-risk of developing an eating disorder and the prevalence of unhealthy eating attitudes and behaviours amongst groups at risk; gender, school or academic year differences were also explored.</p> <p>Methods</p> <p>A cross-sectional study based on self-report was used to screen university students at high-risk for an eating disorder. The sample size was of 2551 university students enrolled in 13 schools between the ages of 18 and 26 years. The instruments included: a social-demographic questionnaire, the Eating Disorders Inventory (EDI), the Body Shape Questionnaire (BSQ), the Symptom Check List 90-R (SCL-90-R), and the Self-Esteem Scale (RSE). The sample design is a non-proportional stratified sample by academic year and school. The prevalence rate was estimated controlling academic year and school. Logistic regression analysis was used to investigate adjusted associations between gender, school and academic year.</p> <p>Results</p> <p>Female students presented unhealthy weight-control behaviours as dieting, laxatives use or self-induced vomiting to lose weight than males. A total of 6% of the females had a BMI of 17.5 or less or 2.5% had amenorrhea for 3 or more months. In contrast, a higher proportion of males (11.6%) reported binge eating behaviour. The prevalence rate of students at high-risk for an eating disorder was 14.9% (11.6–18) for males and 20.8% (18.7–22.8) for females, according to an overall cut-off point on the EDI questionnaire. Prevalence rates presented statistically significant differences by gender (p < 0.001) but not by school or academic year.</p> <p>Conclusion</p> <p>The prevalence of eating disorder risk in university students is high and is associated with unhealthy weight-control practices, similar results have been found in previous studies using cut-off points in questionnaires. These results may be taken into account to encourage early detection and a greater awareness for seeking treatment in order to improve the diagnosis, among students on university campuses.</p

A systematic review of mental disorder, suicide, and deliberate self harm in lesbian, gay and bisexual people

Background: Lesbian, gay and bisexual (LGB) people may be at higher risk of mental disorders than heterosexual people.Method: We conducted a systematic review and meta-analysis of the prevalence of mental disorder, substance misuse, suicide, suicidal ideation and deliberate self harm in LGB people. We searched Medline, Embase, PsycInfo, Cinahl, the Cochrane Library Database, the Web of Knowledge, the Applied Social Sciences Index and Abstracts, the International Bibliography of the Social Sciences, Sociological Abstracts, the Campbell Collaboration and grey literature databases for articles published January 1966 to April 2005. We also used Google and Google Scholar and contacted authors where necessary. We searched all terms related to homosexual, lesbian and bisexual people and all terms related to mental disorders, suicide, and deliberate self harm. We included papers on population based studies which contained concurrent heterosexual comparison groups and valid definition of sexual orientation and mental health outcomes.Results: Of 13706 papers identified, 476 were initially selected and 28 (25 studies) met inclusion criteria. Only one study met all our four quality criteria and seven met three of these criteria. Data was extracted on 214,344 heterosexual and 11,971 non heterosexual people. Meta-analyses revealed a two fold excess in suicide attempts in lesbian, gay and bisexual people [ pooled risk ratio for lifetime risk 2.47 (CI 1.87, 3.28)]. The risk for depression and anxiety disorders (over a period of 12 months or a lifetime) on meta-analyses were at least 1.5 times higher in lesbian, gay and bisexual people (RR range 1.54-2.58) and alcohol and other substance dependence over 12 months was also 1.5 times higher (RR range 1.51-4.00). Results were similar in both sexes but meta analyses revealed that lesbian and bisexual women were particularly at risk of substance dependence (alcohol 12 months: RR 4.00, CI 2.85, 5.61; drug dependence: RR 3.50, CI 1.87, 6.53; any substance use disorder RR 3.42, CI 1.97-5.92), while lifetime prevalence of suicide attempt was especially high in gay and bisexual men (RR 4.28, CI 2.32, 7.88).Conclusion: LGB people are at higher risk of mental disorder, suicidal ideation, substance misuse, and deliberate self harm than heterosexual people