The Cosmic Causal Mass

In order to provide a better understanding of rotating universe models, and in particular the G\"{o}del universe, we discuss the relationship between cosmic rotation and perfect inertial dragging. In this connection, the concept of \emph{causal mass} is defined in a cosmological context, and discussed in relation to the cosmic inertial dragging effect. Then, we calculate the mass inside the particle horizon of the flat $\Lambda$CDM-model integrated along the past light cone. The calculation shows that the Schwarzschild radius of this mass is around three times the radius of the particle horizon. This indicates that there is close to perfect inertial dragging in our universe. Hence, the calculation provides an explanation for the observation that the swinging plane of a Foucault pendulum follows the stars.Comment: 17 pages, 3 figure

STUDY AND MODELING OF HOT TEARING FORMATION

As for most of the topics in the field of solidification, Mert Flemings has always pioneered new ideas. While much of the understanding of hot tearing formation was already known about 30 years ago, he devised with Metz an interesting apparatus for studying the resistance of mushy zones to compression and shearing [1,2]. Part of the results of these tests lead Flemings to become interested in semi-solid processing of metallic alloys, with the success we know today (e.g., production of automobile components by thixocasting). Probably because of that, hot tearing criteria and models have not progressed very much since. However, with the advent of refined stress and solidification models, one sees today renewed interest in hot tearing. The present contribution, after recollecting some of the early work of Flemings in this area, presents recent SEM observations of hot tears in aluminum alloys and in-situ observations of hot tearing formation in organic systems. A recent model of hot tearing, which combines deformation of the mushy zone and interdendritic liquid flow, is also summarized

Direct observation of hot tear formation in organic alloys

Abstract Following the work of Farup et al.

Clinicians' management strategies for patients with dyspepsia: a qualitative approach

BACKGROUND: Symptoms from the upper gastrointestinal tract are frequently encountered in clinical practice and may be of either organic or functional origin. For some of these conditions, according to the literature, certain management strategies can be recommended. For other conditions, the evidence is more ambiguous. The hypothesis that guided our study design was twofold: Management strategies and treatments suggested by different clinicians vary considerably, even when optimal treatment is clear-cut, as documented by evidence in the literature. Clinicians believe that the management strategies of their colleagues are similar to their own. METHODS: Simulated case histories of four patients with symptoms from the upper gastrointestinal tract were presented to 27 Swedish clinicians who were specialists in medical gastroenterology, surgery, and general practice and worked at three hospitals in the southern part of Sweden. The patients' histories contained information on the patient's sex and age and the localisation of the symptoms, but descriptions of subjective symptoms and findings from examinations differed from history to history. Interviews containing open-ended questions were conducted. RESULTS: For the same patient, the management strategies and treatments suggested by the clinicians varied widely, as did the strategies suggested by clinicians in the same speciality. Variation was more pronounced if the case history noted symptoms but no organic findings than if the case history noted unambiguous findings and symptoms. However, even in cases with a consensus in the scientific literature on treatment, the variations in clinicians' opinion on management were pronounced. CONCLUSION: Despite these variations, the clinicians believed that the decisions made by their colleagues would be similar to their own. The overall results of this study indicate that we as researchers must make scientific evidence comprehensible and communicate evidence so that clinicians are able to interpret and implement it in practice. Of particular significance is that scientific evidence leads to an evidence-based care which is effective clinical practice and to the promotion of health from the perspective of the patient, together with cost-effectiveness as a priority

Effect of Fe-rich intermetallics on tensile behavior of Al-Cu 206 cast alloys at solid and near-solid states

Iron is one of the most common impurity elements in Al-Cu 206 cast alloys as it often causes the precipitation of Fe-rich intermetallic phases during solidification due to its extremely low solid solubility in aluminum. The characteristics of the Fe-rich intermetallics, such as type, morphology, size, and distribution, have significant influences on the tensile behaviors of the Al alloys. In the present work, two Al-Cu 206 cast alloys containing different types of Fe-rich intermetallics (dominated by either platelet β-Fe or Chinese script α-Fe) were cast and their tensile tests were performed at both solid (room temperature) and near-solid (2.8 vol. % liquid) states. It is found that the tensile properties in both solid and near-solid states are improved when the Fe-rich intermetallics change from platelet to Chinese script morphologies. During the solid state tensile deformation, the failure occurs mainly along the platelet β-Fe intermetallics/Al matrix interface or within the Chinese script α-Fe particles. In the near-solid state, the alloy containing mainly Chinese script α-Fe is found to have more free flow paths for liquid feeding, leading to improved tensile properties. By contrast, the platelet β-Fe can cause the blockage of the liquid flow paths, leading to the degraded tensile properties and worsened susceptibility to hot tearing

Impact of gastroesophageal reflux disease on patients' daily lives: a European observational study in the primary care setting

<p>Abstract</p> <p>Background</p> <p>The impact of gastroesophageal reflux disease (GERD) on the daily lives of patients managed in primary care is not well known. We report the burden of GERD in a large population of patients managed in primary care, in terms of symptoms and impact on patients' daily lives.</p> <p>Methods</p> <p>RANGE (<it>R</it>etrospective <it>AN</it>alysis of <it>GE</it>RD) was an observational study that was conducted at 134 primary care sites across six European countries. All adult subjects who had consulted their primary care physician (PCP) during a 4-month identification period were screened retrospectively and those consulting at least once for GERD-related reasons were identified. From this population, a random sample of patients was selected to enter the study and attended a follow-up appointment, during which the Reflux Disease Questionnaire (RDQ), the GERD Impact Scale (GIS) and an extra-esophageal symptoms questionnaire were self-administered. Based on medical records, data were collected on demographics, history of GERD, its diagnostic work-up and therapy.</p> <p>Results</p> <p>Over the 4-month identification period, 373,610 subjects consulted their PCP and 12,815 (3.4%) did so for GERD-related reasons. From 2678 patients interviewed (approximately 75% of whom reported taking medication for GERD symptoms), symptom recurrence following a period of remission was the most common reason for consultation (35%). At the follow-up visit, with regard to RDQ items (score range 0–5, where high score = worse status), mean Heartburn dimension scores ranged from 0.8 (Sweden) to 1.2 (UK) and mean Regurgitation dimension scores ranged from 1.0 (Norway) to 1.4 (Germany). Mean overall GIS scores (range 1–4, where low score = worse status) ranged from 3.3 (Germany) to 3.5 (Spain). With regard to extra-esophageal symptoms, sleep disturbance was common in all countries in terms of both frequency and intensity.</p> <p>Conclusion</p> <p>In this large European observational study, GERD was associated with a substantial impact on the daily lives of affected individuals managed in the primary care setting.</p

Doubtful outcome of the validation of the Rome II questionnaire: validation of a symptom based diagnostic tool

<p>Abstract</p> <p>Background</p> <p>Questionnaires are used in research and clinical practice. For gastrointestinal complaints the Rome II questionnaire is internationally known but not validated. The aim of this study was to validate a printed and a computerized version of Rome II, translated into Swedish. Results from various analyses are reported.</p> <p>Methods</p> <p>Volunteers from a population based colonoscopy study were included (n = 1011), together with patients seeking general practice (n = 45) and patients visiting a gastrointestinal specialists' clinic (n = 67). The questionnaire consists of 38 questions concerning gastrointestinal symptoms and complaints. Diagnoses are made after a special code. Our validation included analyses of the translation, feasibility, predictability, reproducibility and reliability. Kappa values and overall agreement were measured. The factor structures were confirmed using a principal component analysis and Cronbach's alpha was used to test the internal consistency.</p> <p>Results and Discussion</p> <p>Translation and back translation showed good agreement. The questionnaire was easy to understand and use. The reproducibility test showed kappa values of 0.60 for GERS, 0.52 for FD, and 0.47 for IBS. Kappa values and overall agreement for the predictability when the diagnoses by the questionnaire were compared to the diagnoses by the clinician were 0.26 and 90% for GERS, 0.18 and 85% for FD, and 0.49 and 86% for IBS. Corresponding figures for the agreement between the printed and the digital version were 0.50 and 92% for GERS, 0.64 and 95% for FD, and 0.76 and 95% for IBS. Cronbach's alpha coefficient for GERS was 0.75 with a span per item of 0.71 to 0.76. For FD the figures were 0.68 and 0.54 to 0.70 and for IBS 0.61 and 0.56 to 0.66. The Rome II questionnaire has never been thoroughly validated before even if diagnoses made by the Rome criteria have been compared to diagnoses made in clinical practice.</p> <p>Conclusion</p> <p>The accuracy of the Swedish version of the Rome II is of doubtful value for clinical practice and research. The results for reproducibility and reliability were acceptable but the outcome of the predictability test was poor with IBS as an exception. The agreement between the digital and the paper questionnaire was good.</p

Effects of iron-rich intermetallics and grain structure on semisolid tensile properties of Al-Cu 206 cast alloys near solidus temperature

The effects of iron-rich intermetallics and grain size on the semisolid tensile properties of Al-Cu 206 cast alloys near the solidus were evaluated in relation to the mush microstructure. Analyses of the stress–displacement curves showed that the damage expanded faster in the mush structure dominated by plate-like β-Fe compared to the mush structure dominated by Chinese script-like α-Fe. While there was no evidence of void formation on the β-Fe intermetallics, they blocked the interdendritic liquid channels and thus hindered liquid flow and feeding during semisolid deformation. In contrast, the interdendritic liquid flows more freely within the mush structure containing α-Fe. The tensile properties of the alloy containing α-Fe are generally higher than those containing β-Fe over the crucial liquid fraction range of ~0.6 to 2.8 pct, indicating that the latter alloy may be more susceptible to stress-related casting defects such as hot tearing. A comparison of the semisolid tensile properties of the alloy containing α-Fe with different grain sizes showed that the maximum stress and elongation of the alloy with finer grains were moderately higher for the liquid fractions of ~2.2 to 3.6 pct. The application of semisolid tensile properties for the evaluation of the hot tearing susceptibility of experimental alloys is discussed

Is upper gastrointestinal radiography a cost-effective alternative to a Helicobacter pylori “Test and Treat” strategy for patients with suspected peptic ulcer disease?

Current clinical consensus supports an initial Helicobacter pylori (HP) “test and treat” approach when compared to immediate endoscopy for patients with suspected peptic ulcer disease. Alternative diagnostic approaches that incorporate upper GI radiography (UGI) have not been previously evaluated. We sought to determine the cost effectiveness of UGI compared to a HP test and treat strategy, incorporating recent data addressing the reduced prevalence of HP, lower cost of diagnostic interventions, and reduced attribution of PUD to HP. METHODS : Using decision analysis, three diagnostic and treatment strategies were evaluated: 1) Test and Treat —initial HP serology, treat patients who test positive with HP eradication and antiulcer therapy; 2) Initial UGI series —treat all patients with documented ulcer disease with HP eradication and antiulcer therapy; and 3) Initial UGI series, HP serology if ulcer present — treat ulcer and HP based on diagnostic test results. RESULTS : The estimated cost per ulcer cured for each strategy were as follows: test and treat, $3,025; initial UGI,$3,690; and UGI with serology, $3,790. The estimated cost per patient treatment were: test and treat,$498; initial UGI, $610; and UGI with serology,$620. When UGI reimbursement was decreased to less than $50, the UGI strategies yielded a lower cost per patient treated than the test and treat strategy. CONCLUSION : At the current level of reimbursement, UGI should not be considered a cost-effective alternative to the HP test and treat strategy for the initial evaluation of patients with suspected peptic ulcer disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73722/1/j.1572-0241.2000.01837.x.pd

Diabetic gastroparesis: Therapeutic options

Gastroparesis is a condition characterized by delayed gastric emptying and the most common known underlying cause is diabetes mellitus. Symptoms include nausea, vomiting, abdominal fullness, and early satiety, which impact to varying degrees on the patient’s quality of life. Symptoms and deficits do not necessarily relate to each other, hence despite significant abnormalities in gastric emptying, some individuals have only minimal symptoms and, conversely, severe symptoms do not always relate to measures of gastric emptying. Prokinetic agents such as metoclopramide, domperidone, and erythromycin enhance gastric motility and have remained the mainstay of treatment for several decades, despite unwanted side effects and numerous drug interactions. Mechanical therapies such as endoscopic pyloric botulinum toxin injection, gastric electrical stimulation, and gastrostomy or jejunostomy are used in intractable diabetic gastroparesis (DG), refractory to prokinetic therapies. Mitemcinal and TZP-101 are novel investigational motilin receptor and ghrelin agonists, respectively, and show promise in the treatment of DG. The aim of this review is to provide an update on prokinetic and mechanical therapies in the treatment of DG