The Design, Construction, and Some Uses of an Automatic Recording Balance

Many chemical and physical reactions are accompanied by changes in weight of the reactants due to evaporation of liquids, evolution of gases, or adsorption of gases. Studies are made using data which show the manner in which the weight changes with time. Kinetic studies are made from a knowledge of the rate of loss or gain of a component. The drying of a precipitate to constant weight involves a loss in weight. Rates of evaporation of liquids from different types of surfaces involve changes of weight as a function of time. Several instruments and methods are used to follow weight changes. Gas buret systems are used to measure the volume of a gaseous component which is adding to or subtracting from the weight of a reactant. The ordinary analytical balance is used to follow weight changes by making intermittent weighings. This latter method involves tedious operations and interruptions of the treatment of the reactants. Effort has been put forth to devise instruments which will automatically weigh substances and record these weighings on some type of graph. Gregg and Wintle (1) devised a glass automatic electrical sorption balance. Gregg (2) later described a recording system for this type balance. Eyrand (3) reported a glass sorption balance of a somewhat different type. Duval (4) described a thermal balance that automatically records changes in weight on film. Described in this paper is an instrument attached to a modified ordinary analytical balance which automatically records on graph paper changes in weight as a function of time

Country differences in the diagnosis and management of coronary heart disease : a comparison between the US, the UK and Germany

Background The way patients with coronary heart disease (CHD) are treated is partly determined by non-medical factors. There is a solid body of evidence that patient and physician characteristics influence doctors' management decisions. Relatively little is known about the role of structural issues in the decision making process. This study focuses on the question whether doctors' diagnostic and therapeutic decisions are influenced by the health care system in which they take place. This non-medical determinant of medical decision-making was investigated in an international research project in the US, the UK and Germany. Methods Videotaped patients within an experimental study design were used. Experienced actors played the role of patients with symptoms of CHD. Several alternative versions were taped featuring the same script with patients of different sex, age and social status. The videotapes were shown to 384 randomly selected primary care physicians in the three countries under study. The sample was stratified on gender and duration of professional experience. Physicians were asked how they would diagnose and manage the patient after watching the video vignette using a questionnaire with standardised and open-ended questions. Results Results show only small differences in decision making between British and American physicians in essential aspects of care. About 90% of the UK and US doctors identified CHD as one of the possible diagnoses. Further similarities were found in test ordering and lifestyle advice. Some differences between the US and UK were found in the certainty of the diagnoses, prescribed medications and referral behaviour. There are numerous significant differences between Germany and the other two countries. German physicians would ask fewer questions, they would order fewer tests, prescribe fewer medications and give less lifestyle advice. Conclusion Although all physicians in the three countries under study were presented exactly the same patient, some disparities in the diagnostic and patient management decisions were evident. Since other possible influences on doctors treatment decisions are controlled within the experimental design, characteristics of the health care system seem to be a crucial factor within the decision making process

A modification of Honoré's triple-link model in the synoptic problem

In New Testament studies, the synoptic problem is concerned with the relationships between the gospels of Matthew, Mark and Luke. In an earlier paper a careful specification in probabilistic terms was set up of Honoré's triple-link model. In the present paper, a modification of Honoré's model is proposed. As previously, counts of the numbers of verbal agreements between the gospels are examined to investigate which of the possible triple-link models appears to give the best fit to the data, but now using the modified version of the model and additional sets of data

Use of the Behavior Assessment Tool in 18 Pilot Residency Programs

Background: The purpose of this study was to determine the feasibility and evaluate the effectiveness of the American Board of Orthopaedic Surgery Behavior Tool (ABOSBT) for measuring professionalism. Methods: Through collaboration between the American Board of Orthopaedic Surgery and American Orthopaedic Association\u27s Council of Residency Directors, 18 residency programs piloted the use of the ABOSBT. Residents requested assessments from faculty at the end of their clinical rotations, and a 360° request was performed near the end of the academic year. Program Directors (PDs) rated individual resident professionalism (based on historical observation) at the outset of the study, for comparison to the ABOSBT results. Results: Nine thousand eight hundred ninety-two evaluations were completed using the ABOSBT for 449 different residents by 1,012 evaluators. 97.6% of all evaluations were scored level 4 or 5 (high levels of professional behavior) across all of the 5 domains. In total, 2.4% of all evaluations scored level 3 or below reflecting poorer performance. Of 431 residents, the ABOSBT identified 26 of 32 residents who were low performers (2 or more \u3c level 3 scores in a domain) and who also scored below expectations by the PD at the start of the pilot project (81% sensitivity and 57% specificity), including 13 of these residents scoring poorly in all 5 domains. Evaluators found the ABOSBT was easy to use (96%) and that it was an effective tool to assess resident professional behavior (81%). Conclusions: The ABOSBT was able to identify 2.4% low score evaluations ( Level of Evidence: Level II

Performance-based financing as a health system reform : mapping the key dimensions for monitoring and evaluation

Peer reviewedPublisher PD

A Vaccine against CCR5 Protects a Subset of Macaques upon Intravaginal Challenge with Simian Immunodeficiency Virus SIVmac251

As an alternative to targeting human immunodeficiency virus (HIV), we have developed vaccines targeting CCR5, a self-protein critically involved in HIV replication and pathogenesis. By displaying peptides derived from CCR5 at high density on the surface of virus-like particles, we can efficiently induce high-titer IgG antibodies against this self-molecule. Here, we investigated whether prophylactic immunization of rhesus macaques with a particle-based vaccine targeting two regions of macaque CCR5 could prevent or suppress vaginal infection with highly virulent SIVmac251. Twelve macaques were vaccinated with a bacteriophage Qß-based vaccine targeting macaque CCR5 (Qß.CCR5). Six control animals were immunized with the Qß platform alone. All animals immunized with Qß.CCR5 developed high-titer anti-CCR5 antibody responses. Macaques were vaginally challenged with a high dose of SIVmac251. The mean peak viral RNA levels in the vaccinated groups were 30-fold lower than in the control group (106.8 versus 108.3 copies/ml plasma). Three of the 12 vaccinated macaques dramatically suppressed simian immunodeficiency virus (SIV) replication: peak viral loads were low (103 to 104 RNA copies/ml), and SIV RNA became undetectable from 6 weeks onward. No viral RNA or DNA could be detected in colon and lymph node biopsy specimens collected 13 months after challenge. In vivo depletion of CD8+ cells failed to induce a viral rebound. However, once anti-CCR5 antibody responses had waned, the 3 animals became infected after intravaginal and/or intravenous rechallenge. In conclusion, vaccination against CCR5 was associated with dramatic suppression of virus replication in a subset (25%) of macaques. These data support further research of vaccination against CCR5 to combat HIV infection

The CAESAR New Frontiers Mission: Comet Surface Sample Acquisition and Preservation

NASA recently selected the Comet Astrobiology Exploration Sample Return (CAESAR) mission for Phase A study in the New Frontiers Program. This mission will acquire and return to Earth for laboratory analysis at least 80 g of surface material from the nucleus of comet 67P/Churyumov-Gerasimenko (hereafter 67P). CAESAR will characterize the surface region sampled, preserve the sample in a pristine state, and return evolved volatiles by capturing them in a separate gas reservoir. The system protects both volatile and non-volatile components from contamination or alteration thatwould hamper their scientific analysis. Laboratory analyses of comet samples provide unparalleled knowledge about the presolar history through the initial stages of planet formation to the origin of life

In Vitro Studies Evaluating Leaching of Mercury from Mine Waste Calcine Using Simulated Human Body Fluids

In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almadén, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute primary ore or compounds formed during Hg retorting. Elevated leachate Hg concentrations were found during calcine leaching using a simulated gastric fluid (as much as 6200 μg of Hg leached/g sample). Elevated Hg concentrations were also found in calcine leachates using a simulated lung fluid (as much as 9200 μg of Hg leached/g), serum-based fluid (as much as 1600 μg of Hg leached/g), and water of pH 5 (as much as 880 μg of Hg leached/g). The leaching capacity of Hg is controlled by calcine mineralogy; thus, calcines containing soluble Hg compounds contain higher leachate Hg concentrations. Results indicate that ingestion or inhalation of Hg mine-waste calcine may lead to increased Hg concentrations in the human body, especially through the ingestion pathway