Phase Diagram of SO(3) Lattice Gauge Theory at Finite Temperature

The phase diagram of SO(3) lattice gauge theory at finite temperature is investigated by Monte Carlo techniques with a view i) to understand the relationship between the deconfinement phase transitions in the SU(2) and SO(3) lattice gauge theories and ii) to resolve the current ambiguity of the nature of the high temperature phases of the latter. Phases with positive and negative adjoint Polyakov loop are shown to have the same physics. A first order deconfining phase transition is found for N_t=4.Comment: 3 pages, 2 figures, latex2e, uses espcrc2.sty. Contribution to Lattice '97, Edinburgh, July 1997, to appear in Nucl. Phys. B (Proc. Suppl.) Latex command for figures correcte

Gold-alkynyls in catalysis : Alkyne activation, gold cumulenes and nuclearity

The use of cationic gold(i) species in the activation of substrates containing CC bonds has become a valuable tool for synthetic chemists. Despite the seemingly simple label of 'alkyne activation', numerous patterns of reactivity and product structure are observed in systems employing related substrates and catalysts. The complications of mechanistic determination are compounded as the number of implicated gold(i) centres involved in catalysis increases and debate about the bonding in proposed intermediates clouds the number and importance of potential reaction pathways. This perspective aims to illustrate some of the principles underpinning gold-alkynyl interactions whilst highlighting some of the contentious areas in the field and offering some insight into other, often ignored, mechanistic possibilities based on recent findings

A systematic review of the nutritional consequences of esophagectomy

Background & aims As improved outcomes after esophagectomy have been observed over the last two decades, the focus on care has shifted to survivorship and quality of life. The aim of this review was to determine changes in nutrition after esophagectomy and to assess the evidence for extended nutrition support. Methods A search strategy was developed to identify primary research reporting change in nutritional status a minimum of one month after esophagectomy. Results Changes in nutritional parameters reported by 18 studies indicated a weight loss of 5–12% at six months postoperatively. More than half of patients lost >10% of body weight at 12 months. One study reported a persistent weight loss of 14% from baseline three years after surgery. Three studies reporting on longer term follow up noted that 27%–95% of patients failed to regain their baseline weight. Changes in dietary intake (three studies) indicated inadequate energy and protein intake up to three years after surgery. Global quality of life scores reported in one study correlated with better weight preservation. There were a high frequency of gastrointestinal symptoms reported in six studies, most notably in the first year after surgery, but persisting up to 19 years. Extended enteral nutrition on a selective basis has been reported in several studies. Conclusions Nutritional status is compromised in the months/years following oesophagectomy and may never return to baseline levels. The causes/consequences of weight loss/impaired nutritional intake require further investigation. The role of extended nutritional support in this population remains unclear

Putting pharmaceuticals into the wider context of challenges to fish populations in rivers

The natural range of fish species in our rivers is related to flow, elevation, temperature, local habitat and connectivity. For over 2000 years, humans have altered to varying degrees the river habitat. In the past 200 years, we added to the environmental disruption by discharging poorly treated sewage, nutrients and industrial waste into our rivers. For many rivers, the low point arrived during the period of 1950s–1970s, when rapid economic development overrode environmental concerns and dissolved oxygen concentrations dropped to zero. In these more enlightened times, gross river pollution is a thing of the past in the Developed World. However, persistent legacy chemical contaminants can be found in fish long after their discharge ceased. Changes in habitat quality and morphology caused and continue to cause the disappearance of fish species. The range of fish stressors has now increased as temperatures rise, and non-native fish introductions bring new diseases. The threat from pharmaceuticals to fish populations remains hypothetical, and no studies have yet linked change in fish populations to exposure

Designing pre-bariatric surgery education: The value of Patients' experiences

Within the field of bariatric surgery, preoperative education to empower patients to adapt to the postoperative lifestyle and get the best outcomes in terms of health and quality of life is not standardised across the UK and is based mainly on clinical experience. In this study, the authors used qualitative research and a structured framework to design a preoperative psychosocial education course for people undergoing surgery. Qualitative interviews were performed to determine issues that previous surgery recipients felt were missing from their preoperative education, and the current educational course was redesigned to include this content. The study provides a template from which other Trusts could evaluate and improve their education

Patient and Family Caregivers’ Experiences of Living With a Jejunostomy Feeding Tube After Surgery for Esophagogastric Cancer

BACKGROUND: Jejunostomy feeding tubes (JFTs) can be used to provide nutrition support to patients who have had surgery for esophagogastric cancer. Although previous research reports how patients cope with a gastrostomy tube, little is known about the impact of having a JFT. The aim of this qualitative study was to explore how patients and their informal caregivers experience living with a JFT in the first months following surgery. METHODS: Participants were purposively sampled from a cohort of patients recruited to a trial investigating home enteral nutrition vs standard care after esophagogastric surgery for cancer. The sampling framework considered age, sex, and marital status. Informal caregivers were also invited to participate. Interviews were audio recorded, transcribed verbatim, and anonymized. Inductive thematic analysis was used to identify key themes related to living with a JFT. RESULTS: Fifteen patient interviews were conducted; 8 also included a family caregiver. Analysis of the data resulted in 2 main themes: "challenges" and "facilitators" when living with a JFT. While "physical effects," "worries" and "impact on routine" were the main challenges, "support," "adaptation" and "perceived benefit" were what motivated continuation of the intervention. CONCLUSION: Findings suggest that participants coped well with a JFT, describing high levels of compliance with stoma care and the feeding regimen. Nonetheless, disturbed sleep patterns and stoma-related problems proved troublesome. A better understanding of these practical challenges, from the patient and family caregiver perspective, should guide healthcare teams in providing proactive support to avoid preventable problems

Two Rb-Sr Whole Rock Isochrons from Plutons In the Cobequid Highlands, Nova Scotia, Canada

Two Rb-Sr Hhole rock isochrons have been obtained from plutons In the Cobequid Highlands of Nova Scotia: the Debert River and Hart Lake-Byers Lake Plutons. The undeformed, unfoilated Debert River Pluton yielded an age of 596± 70 Ma and an Initial 87Sr/88Sr ratio of 0.7059 ± 0.0007. This age places an upper age limit on the detonation recorded In the Folly River Schist (youngest unit of the Bass River Complex), the d I or I tic Frog Lake Pluton, and the sedimentary rocks immediately north and east of the Debert River Pluton. The Hart Lake-Byers Lake Pluton yielded anageof348±5Maandan Initial 87Sr/88Sr ratio of 0.7046 ± 0.0008. The similarity of this age to that of the adjacent felsic volcanics of the Byers Brook For nation suggests that they are comagmatic and confine that a Carboniferous igneous event forms an Important part of the geological history of the Cobequid Highlands. The Initial 87Sr/88Sr ratio and the blotite-hornblende content of the two granites suggest a mafic Igneous loner crustal source or possible untie component for the magma. RÉSUMÉ Les plutons de Debert River et Hart Lake-Byers Lake dans les monts Cobequld en Nouvel le-Écosse ont livre deux isochrones Rb-Sr de roche globale. Il déformé ni fellé, le pluton de Debert River a donné un âge de 596± 70 Ma et un rapport 87Sr/88Sr initial de 0.7059 ± 0.0007. Ceci place une limite supérieure sur l’âge de la déformation enregistrée dans le schiste de Folly River (L’unité la plus jeune du complexe de Bass River), le pluton diorltique de Frog Lake et dans les roches sédimentaires Jouxtant le pluton de Debert River au nord et à l’est. Le pluton de Hart Lake-Byers Lake à produit un âge de 348 ± 5 Ma et un rapport isotopique 87Sr/88Sr initial de 0.7046 ± 0.008. Cet âge, similaire à ceux des volcanites felslques adjacentes de la formation de Byers Brook, suggére qu'lis sent comagnatiques, signe evident qu'un épisode igné carbonifère forme l’un des faits majeurs de L’histoire géologique des monts Cobequid. Le rapport 87Sr/88Sr initial et la teneur en blotite et hornbIende de ces deux granites suggérent une genèse crustale profonde du magma avec une possible contribution mantellique. [Traduit par le journal

Phase Transitions in SO(3) Lattice Gauge Theory

The phase diagram of SO(3) lattice gauge theory is investigated by Monte Carlo techniques on both symmetric and asymmetric lattices with a view (i) to understanding the relationship between the bulk transition and the deconfinement transition, and (ii) to resolving the current ambiguity about the nature of the high temperature phase. A number of tests, including an introduction of a magnetic field and measurement of different correlation functions in the phases with positive and negative values for the adjoint Polyakov line, lead to the conclusion that the two phases correspond to the same physical state. Studies on lattices of different sizes reveal only one phase transition for this theory on all of them and it appears to have a deconfining nature.Comment: Latex 19 pages, 9 figures. Minor changes in introduction and summary sections. The version that appeared in journa

Images in Christmas Balls

We describe light-reflection properties of spherically curved mirrors, like balls in the Christmas tree. In particular, we study the position of the image which is formed somewhere beyond the surface of a spherical mirror, when an eye observes the image of a pointlike light source. The considered problem, originally posed by Abu Ali Hasan Ibn al-Haitham -- alias Alhazen -- more than a millennium ago, turned out to have the now well known analytic solution of a biquadratic equation, being still of great relevance, e.g. for the aberration-free construction of telescopes. We do not attempt to perform an exhaustive survey of the rich historical and engineering literature on the subject, but develop a simple pedagogical approach to the issue, which we believe to be of continuing interest in view of its maltreating in many high-school textbooks.Comment: 13 pages, 7 figures plain LaTeX; Also see http://cft.fis.uc.pt/eef/mirrors.htm, revised version has simplified formulas, more transparent for a wider audience, one reference adde

Food security, nutrition and health of food bank attendees in an English city: A cross-sectional study

Food banks in contemporary Britain are feeding record numbers of people. Little is known about attendees’ level of food insecurity, background diet quality or health. We surveyed 112 food bank attendees. Over 50% had experienced food shortage with hunger on a weekly basis or more often. Obesity and mental health problems were prevalent in women. Diet quality was poor, with energy, protein, fibre, iron and calcium intakes inadequate, while saturated fat and sugars intake were disproportionate. Women had poorer diet quality than men. Such patterns may lead to ill health