4,064 research outputs found
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The Sources of the Secret des Secrets of Jofroi de Watreford
A French version of the pseudo-Aristotelian, Secretum Secretorum, made in the second half of the thirteenth century by the Dominican Jofroi de Watreford, assisted in some way by Servale Copale, has attracted more attention than it would have otherwise done owing to a statement of the principal author in the dedicatory introduction.
This general statement upon the sources of the work has been misunderstood, and has called forth unnecessary explanations, because more specific statements in other parts of the work have not been noted. The passage cited above was probably the only authority on which the historian of the Dominican order based his assertion that Jofroi knew both Arabic and Greek, and Knust believed it sufficient evidence for the existence of a Greek Secretum Secretorum
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La nouvelle française au XV siècle (Bibliothèque du XV° siècle, T. XII). Werner Söderhielm, Paris, Champion, 1910. Pp. xii + 237.
Professor Söderhjelm who bas made some most significant contributions to comparative literature in various studies on the sources of Jehan de Paris, and the works of Antoine de la Sale and Martial d'Auvergne, in which he has also added to our knowledge of the life and art of the known authors, undertakes, in his La nouvelle française au XV siécle, to complete his survey of the literary genre to which these works belong, by tracing its evolution, and its place in French literature and narrative style. For his task he has aIl the requisite qualities; writing out of a full knowledge of his subject, he shows a power of subtle and broad synthetic treatment, a well-balanced a perception of the delicate shades of style
Fate of the World Rests on Science Teachers: Asimov
Dr. Isaac Asimov, biochemist, science writer, and former teacher, gave the Fellows Address at the 78th Science Teachers Association of New York State Conference last year. In his presentation he defined science as an attempt to understand the rules that govern the universe, an attempt that was of no practical purpose before the 18th century. The following excerpts were reported by Virginia L. Dobson and George Hamilton, Texas A & M University, College Station, Texas
Mediation of the solar wind termination shock by non-thermal ions
Broad regions on both sides of the solar wind termination shock are populated by high intensities of non- thermal ions and electrons. The pre- shock particles in the solar wind have been measured by the spacecraft Voyager 1 ( refs 1 - 5) and Voyager 2 ( refs 3, 6). The post- shock particles in the heliosheath have also been measured by Voyager 1 ( refs 3 - 5). It was not clear, however, what effect these particles might have on the physics of the shock transition until Voyager 2 crossed the shock on 31 August - 1 September 2007 ( refs 7 - 9). Unlike Voyager 1, Voyager 2 is making plasma measurements(7). Data from the plasma(7) and magnetic field(8) instruments on Voyager 2 indicate that non- thermal ion distributions probably have key roles in mediating dynamical processes at the termination shock and in the heliosheath. Here we report that intensities of low- energy ions measured by Voyager 2 produce non- thermal partial ion pressures in the heliosheath that are comparable to ( or exceed) both the thermal plasma pressures and the scalar magnetic field pressures. We conclude that these ions are the >0.028 MeV portion of the non- thermal ion distribution that determines the termination shock structure(8) and the acceleration of which extracts a large fraction of bulk- flow kinetic energy from the incident solar wind(7).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62516/1/nature07030.pd
Use of Psychosocial Support Services Among Male Veterans Affairs Colorectal Cancer Patients
The authors describe use of psychosocial services within +/− 3 months of diagnosis among male colorectal cancer (CRC) patients treated within the Veterans Affairs (VA) health care system. Analysis included 1,199 patients with CRC treated at 27 VA medical centers primarily diagnosed between the periods 2005 to 2007. Of the patients, 78.6% received some form of psychosocial support, including 50.5% social work, 58.9% chaplain, 6.2% psychologist, 7.1% psychiatry, 3.5% mental health nurse, and 4.4% other. Logistic regression results indicate that rectal cancer patients were less likely to receive psychosocial services (odds ratio = .65, 95% confidence interval [0.43, 0.97]). The majority of patients in the VA receive some type of psychosocial service at the time of CRC diagnosis
Placental secretome characterization identifies candidates for pregnancy complications.
Alterations in maternal physiological adaptation during pregnancy lead to complications, including abnormal birthweight and gestational diabetes. Maternal adaptations are driven by placental hormones, although the full identity of these is lacking. This study unbiasedly characterized the secretory output of mouse placental endocrine cells and examined whether these data could identify placental hormones important for determining pregnancy outcome in humans. Secretome and cell peptidome analyses were performed on cultured primary trophoblast and fluorescence-activated sorted endocrine trophoblasts from mice and a placental secretome map was generated. Proteins secreted from the placenta were detectable in the circulation of mice and showed a higher relative abundance in pregnancy. Bioinformatic analyses showed that placental secretome proteins are involved in metabolic, immune and growth modulation, are largely expressed by human placenta and several are dysregulated in pregnancy complications. Moreover, proof-of-concept studies found that secreted placental proteins (sFLT1/MIF and ANGPT2/MIF ratios) were increased in women prior to diagnosis of gestational diabetes. Thus, placental secretome analysis could lead to the identification of new placental biomarkers of pregnancy complications
A multi-lake comparative analysis of the General Lake Model (GLM): Stress-testing across a global observatory network
The modelling community has identified challenges for the integration and assessment of lake models due to the diversity of modelling approaches and lakes. In this study, we develop and assess a one-dimensional lake model and apply it to 32 lakes from a global observatory network. The data set included lakes over broad ranges in latitude, climatic zones, size, residence time, mixing regime and trophic level. Model performance was evaluated using several error assessment metrics, and a sensitivity analysis was conducted for nine parameters that governed the surface heat exchange and mixing efficiency. There was low correlation between input data uncertainty and model performance and predictions of temperature were less sensitive to model parameters than prediction of thermocline depth and Schmidt stability. The study provides guidance to where the general model approach and associated assumptions work, and cases where adjustments to model parameterisations and/or structure are required
Probing the use of long lived intra-ligand π-π * excited states for photocatalytic systems: a study of the photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)]
We report the excited state photophysics and photochemistry of [ReCl(CO)3(dppz-(CH3)2)] (dppz-(CH3)2 = 11,12-dimethyl-dipyrido[3,2-a:2’,3’-c]phenazine) in CH3CN using timeresolved infrared (TRIR) and Fourier transform infrared (FTIR) spectroscopy. Excitation of the 1MLCT (metal-to-ligand charge transfer) band of [ReCl(CO)3(dppz-(CH3)2)] populates a 3MLCT excited state which rapidly interconverts on a timescale < 1 ns to a long lived IL (intra-ligand) π-π* excited state with a lifetime of 190 (± 5) ns. In the presence of an electron donor (NEt3), the IL excited state of [ReCl(CO)3(dppz-(CH3)2)] can be reductively quenched to [ReCl(CO)3(dppz-(CH3)2)]− with the radical in the latter localised on the distal phenazine (phz) portion of the dppz ligand. The phz based electron in [ReCl(CO)3(dppz-(CH3)2)]− has minimal interaction with the rhenium metal centre which increases the stability of the photosensitiser in its reduced form. In non-dried, non-degassed CH3CN (1 M NEt3), [ReCl(CO)3(dppz-(CH3)2)]− shows no significant change in the carbonyl region of the IR spectrum for at least 2 hours during continuous photolysis. In addition, we investigate the use of [ReCl(CO)3(dppz-(CH3)2)]− to reduce the previously studied catalyst [NiFe2], with facile electron transfer from [ReCl(CO)3(dppz-(CH3)2)]− to form [NiFe2]–
The formation, properties and impact of secondary organic aerosol: current and emerging issues
Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with an update on the current state of knowledge on the global SOA budget and is followed by an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail: molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed
Diagnosis of childhood tuberculosis and host RNA expression in Africa
Improved diagnostic tests for tuberculosis in children are needed. We hypothesized that transcriptional signatures of host blood could be used to distinguish tuberculosis from other diseases in African children who either were or were not infected with the human immunodeficiency virus (HIV
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