The Valence of Sulfur in Dithionates

It has been shown by Lindh [1] and others [2] that the shift in the K absorption edges for various compounds of sulfur, chlorine, phosphorous, iron, and some other substances, depends chiefly on the valence of the element in a given compound. With increasing valence in a given element the wave-length of the edge shifts to smaller values. Stelling [3] has explained the effect of valence as being due to the screening effect of electrons in external parts of atoms. To be sure, other factors influence the position of the edges, such as other elements occurring in the compounds, and lattice structure, but these factors produce in general only minor fluctuations around a mean value, whereas the mean values for the several valences show rather wide divergences. For example, the wave-lengths of the principal K edge of a large number of 4- and 6-valent inorganic sulfur compounds practically all lie within half an X-unit of the means of their respective groups, whereas the means themselves are separated by 8 X. U. A similar state of affairs is observed in the 2-valent compounds. The edges do not lie quite so close to the mean, but the mean is 13 X. U. from that of the 4-valent compounds. All the substances thus far investigated bear out the general statements above. In view of the rather large body of facts now before us, it seems legitimate to try to use x-ray absorption data to obtain information on the valence state of an element in a compound. The substance used in the present investigation was potassium dithionate, the object being to determine the state of the two sulfur atoms in K2S2O6. Lindh [4] has already shown that for Na2S2O3 and some other thiosulfates there is not just a simple absorption edge, but two edges, corresponding in position to the valence states SII and probably Siv, which states are generally assumed by chemists for the two sulfur atoms in the thiosulfates. Now if valence is calculated in the usual way, then on the assumption that the sulfur atoms of the dithionates are in the same state we get for them a valence of V, and we would expect to find the K absorption edge corresponding to a single state, rather than the two edges shown by the thiosulfates

Consequences of divergence and introgression for speciation in Andean cloud forest birds

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137772/1/evo13251.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137772/2/evo13251_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137772/3/evo13251-0001-sup-SuppMat.pd

Photon Antibunching in the Photoluminescence Spectra of a Single Carbon Nanotube

We report the first observation of photon antibunching in the photoluminescence from single carbon nanotubes. The emergence of a fast luminescence decay component under strong optical excitation indicates that Auger processes are partially responsible for inhibiting two-photon generation. Additionally, the presence of exciton localization at low temperatures ensures that nanotubes emit photons predominantly one by one. The fact that multiphoton emission probability can be smaller than 5% suggests that carbon nanotubes could be used as a source of single photons for applications in quantum cryptography.Comment: content as publishe

Effects Of Daily Morphine Administration And Deprivation On Choice And Demand For Remifentanil And Cocaine In Rhesus Monkeys

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96717/1/jeab.2011.95-75.pd

IGF paracrine and autocrine interactions between conceptus and oviduct.

Development in vitro is influenced by embryo density, serum, somatic cell co-culture and the production of \u27embryotrophic\u27 paracrine and autocrine factors. Research in our laboratory has focussed principally on the insulin-like growth factor (IGF) family. We have demonstrated that pre-attachment bovine and ovine embryos express mRNAs encoding a number of growth factor ligand and receptor genes including all members of the IGF ligand and receptor family throughout this developmental interval. In addition, early embryos express mRNAs encoding IGF-binding proteins (IGFBPs) 2-5 from the one-cell to the blastocyst stage and IGFBP5 mRNA at the blastocyst stage. Cultured bovine blastocysts release up to 35 pg per embryo in 24 h, whereas release of IGF-I was below detectable values. Analysis extended to bovine oviductal cultures has also demonstrated that mRNAs encoding these IGF family members are present throughout an 8 day culture period. Transcripts encoding IGFBPs 2-6 were also present. Release of both IGFs was recorded over an 8 day culture period. IGF-II release was significantly greater than that observed for IGF-I. Therefore, the IGFs are present throughout the maternal environment during early embryo development. The oocyte, within the follicle, is held in an environment high in IGFs and IGFBPs. The zygote, after fertilization, is maintained in an IGF-rich environment while free-living in the oviduct and the uterus. This review is focused on the IGF family and IGFBPs and their roles in enhancing development up to the blastocyst stage

Describing Healthcare Concerns of Young People and Adults with Cerebral Palsy

The purpose of this study was to identify healthcare concerns of young people and adults with cerebral palsy (CP) in the Transitional and Lifelong Care (TLC) program, and determine whether there were patient factors associated with the number of healthcare concerns. A retrospective chart review of initial TLC consultations was completed (n = 241). Descriptive and inferential statistics were used to explore and explain patterns in the sample population. The participants reported a high number of concerns of varied nature that were not easily predicted by condition-specific or demographic variables. This study may better healthcare delivery for young people and adults with CP by raising awareness of the health needs of this population, and potentially leading to the creation of intervention and monitoring guidelines.Furthermore, this research has strong potential to influence priority setting in the development of adult-based clinical programs and contribute to best practices for effective transitional care

Associations of health behaviors with human papillomavirus vaccine uptake, completion, and intentions among female undergraduate students

This study explored associations between health behaviors and human papillomavirus vaccine receipt/intentions among female undergraduates. Participants (N = 286) completed a survey assessing human papillomavirus vaccine uptake (receiving 1–3 shots vs no shots), completion (receiving 3 shots vs 1–2 shots), and intentions as well as various health behaviors. Human papillomavirus vaccine uptake and completion were associated with receipt of other preventive medical care; completion was associated with having a regular healthcare provider. Among unvaccinated students (n = 115), increased human papillomavirus vaccine intentions were associated with flu shot and human immunodeficiency virus test receipt. Findings suggest promoting human papillomavirus vaccination with other preventive medical care might improve vaccine receipt

Assessing Unit‐Price Related Remifentanil Choice In Rhesus Monkeys

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96725/1/jeab.2006.108.05.pd

Effects of circadian rhythm phase alteration on physiological and psychological variables: Implications to pilot performance (including a partially annotated bibliography)

The effects of environmental synchronizers upon circadian rhythmic stability in man and the deleterious alterations in performance and which result from changes in this stability are points of interest in a review of selected literature published between 1972 and 1980. A total of 2,084 references relevant to pilot performance and circadian phase alteration are cited and arranged in the following categories: (1) human performance, with focus on the effects of sleep loss or disturbance and fatigue; (2) phase shift in which ground based light/dark alteration and transmeridian flight studies are discussed; (3) shiftwork; (4)internal desynchronization which includes the effect of evironmental factors on rhythmic stability, and of rhythm disturbances on sleep and psychopathology; (5) chronotherapy, the application of methods to ameliorate desynchronization symptomatology; and (6) biorythm theory, in which the birthdate based biorythm method for predicting aircraft accident susceptability is critically analyzed. Annotations are provided for most citations

Self-efficacy mediates the relationship between social norms and HPV vaccine intentions in undergraduate students

poster abstractHuman papillomavirus (HPV) is the most common sexually transmitted infection in the United States. The HPV vaccine reduces incidences of genital warts and certain cancers among both men and women. Unfortunately, many undergraduate students have not been vaccinated. Previous research suggests students are more likely to report greater intentions to get vaccinated when others (e.g., friends, physicians) believe they should receive the vaccine; that is, greater social norms are associated with greater vaccine intentions. However, few studies have examined potential mediators of this association. Drawing from the Theory of Planned Behavior and the Health Belief Model, we hypothesized that social norms would be related to vaccine intentions through self-efficacy. Undergraduate students (N=210) who had not received the HPV vaccine completed an online survey. Participants were predominately White (72%), female (67%), heterosexual (92%), and on average 19.9 years of age (SD=3.2). Forty-nine percent were in a romantic relationship, and 55% were sexually active within the past three months. Participants completed HPV vaccine specific measures, including social norms regarding vaccination, self-efficacy for vaccination, and vaccine intentions. Two mediation analyses (one per gender) were conducted to examine whether self-efficacy mediated the relationship between social norms and vaccine intentions. For women and men, greater social norms were related to greater self-efficacy, and greater selfefficacy was related to greater vaccine intentions (ps<0.05); additionally, social norms were indirectly related to vaccine intentions through self-efficacy (p<0.05). For women, after accounting for self-efficacy, social norms were still significantly related to intentions (p<0.05). For men, however, after accounting for self-efficacy, social norms were not significantly related to intentions (p=0.75). Consistent with previous findings, social norms were positively related to vaccine intentions; however, we found that this association was mediated by self-efficacy. Future intervention studies should consider targeting social norms and improving students’ confidence in their ability to obtain the vaccine