The impacts of climate zone, wall insulation, and window types on building energy performance

Building energy consumption tends to increase over the next few decades due to the increasing level of urbanization and population. These days much attention has been paid to the enhancement of energy performance of residential and non-residential structures. One should consider various factors for proper building thermal design and assessment. In this study, a simulation-based investigation is applied to analyze the influence of building envelope, climate region, and window's physical features on energy performance. Building's energy consumption and amount of CO2 emissions are studied. EnergyPlus tool interfaced with DesignBuilder software was used to perform energy simulations. Annual energy analyses are carried out on the reference house model over the five climate regions from the Koppen-Geiger climate classification map. According to results obtained, climate condition, wall envelope, window type, and window to wall ratio can significantly influence a building's energy performance. Application of insulating materials and the use of specific window type results in considerable energy savings and reduction of CO2 emission amounts

Wake response to an ocean-feedback mechanism: Madeira Island case study

This discussion focused on the numerical study of a wake episode. The Weather Research and Forecasting model was used in a downscale mode. The current literature focuses the discussion on the adiabatic dynamics of atmospheric wakes. Changes in mountain height and consequently on its relation to the atmospheric inversion layer should explain the shift in wake regimes: from a 'strong-wake' to a 'weak-wake' scenario. Nevertheless, changes in SST variability can also induce similar regime shifts. Increase in evaporation, contributes to increase convection and thus to an uplift of the stratified atmospheric layer, above the critical height, with subsequent internal gravity wave activity.Comment: Under review proces

A single-photon transistor using nano-scale surface plasmons

It is well known that light quanta (photons) can interact with each other in nonlinear media, much like massive particles do, but in practice these interactions are usually very weak. Here we describe a novel approach to realize strong nonlinear interactions at the single-photon level. Our method makes use of recently demonstrated efficient coupling between individual optical emitters and tightly confined, propagating surface plasmon excitations on conducting nanowires. We show that this system can act as a nonlinear two-photon switch for incident photons propagating along the nanowire, which can be coherently controlled using quantum optical techniques. As a novel application, we discuss how the interaction can be tailored to create a single-photon transistor, where the presence or absence of a single incident photon in a ``gate'' field is sufficient to completely control the propagation of subsequent ``signal'' photons.Comment: 20 pages, 4 figure

Future costs in cost-effectiveness analysis: an empirical assessment

To assess the usage of cost-utility analysis (CUA) in oral health interventions and to evaluate the methods used and the reporting quality of CUA in publications on oral health interventions

A Danish population-based cohort study of newly diagnosed asthmatic children's care pathway – adherence to guidelines

<p>Abstract</p> <p>Background</p> <p>Asthma is the most common chronic disease in childhood. Large variations exist concerning the number of children being treated by general practitioners and by specialists. Consequently, health related costs due to this disease vary as care by specialists is more expensive compared with care by general practitioners. Little is known of the consequences of these variations concerning the quality of care. The aim of the study was to analyse associations between care providers and adherence to guidelines concerning frequency of contacts with the health service due to asthma.</p> <p>Methods</p> <p>A cohort study was performed of 36,940 incident asthmatic children's (aged 6–14) contacts with the health service using the unique personal registration number to link data from five national registries. The prevalence ratios were calculated for associations between provider (general practitioner, primary care specialist, hospital specialist or both GP and specialist) and adherence with guidelines concerning three indicators of quality of care pathway: 1) diagnostic examination of lung function at start of medical treatment 2) follow-up the first six months and 3) follow-up the next six months. The associations were adjusted for sex, age, socioeconomic status, county, and severity of disease.</p> <p>Results</p> <p>Most children (70.3%) had only been seen by their GP. About 80% of the children were treated with inhaled steroids, 70% were treated with inhaled steroids as well as inhaled beta2agonists and 13% were treated with inhaled beta2agonists only. A total of 12,650 children (34.2%) had no registered asthma-related contacts with the health service except when redeeming prescriptions. Care was in accordance with guidelines in all three indicators of quality in 7% of the cases (GPs only: 3%, primary care specialists only: 16%, hospital specialists: 28%, and both GP and specialists: 13%). Primary care specialists had a 5.01, hospital specialists a 8.81 and both GP and specialists a 4.32 times higher propensity to provide a clinical pathway according to guidelines compared to GPs alone.</p> <p>Conclusion</p> <p>The majority of the children were seen in general practice. Hospital specialists provided care in accordance with guidelines nine times more often compared with GPs, but still only one quarter of these children had pathways in accordance with guidelines. It is relevant to study further if these lacks of adherence to guidelines have implications for the asthmatic children or if guidelines are too demanding concerning frequency of follow-up or if asthmatic children should be stratified to different care pathways.</p

Prognosis of ovarian cancer subsequent to venous thromboembolism: a nationwide Danish cohort study

BACKGROUND: Venous thromboembolism (VTE) is associated with ovarian cancer and may impact the prognosis of ovarian cancer. Our aims were to examine the extent of disease at the time of the diagnosis of ovarian cancer and to estimate the impact of VTE on survival of ovarian cancer. METHODS: We identified 12,835 ovarian cancer patients diagnosed from 1980 to 2003 in the Danish Cancer Registry and obtained information on previous primary VTE diagnosis from the Danish National Hospital Discharge Registry. Ovarian cancer patients with previous VTE related to other cancers, surgery, or pregnancy were excluded. The vital status was determined by linking data to the Civil Registration System. RESULTS: We identified 50 ovarian cancer patients diagnosed less than 4 months after the VTE and 78 ovarian cancer patients diagnosed more than 4 months after the VTE diagnosis. Advanced stages tended to be more common among patients with VTE. One-year survivals were 44% and 54% among the two VTE groups, compared with 63% among patients without VTE. Adjusted (for age, calendar time, comorbidity, and FIGO-stage) mortality ratios were 1.7 (95% CI = 1.2–2.5) and 1.2 (95% CI = 0.8–1.7), respectively. CONCLUSION: Ovarian cancer diagnosed less than four months before VTE is associated with an advanced stage and a poorer prognosis

Prenatal Stress Exposure Related to Maternal Bereavement and Risk of Childhood Overweight

BACKGROUND: It has been suggested that prenatal stress contributes to the risk of obesity later in life. In a population-based cohort study, we examined whether prenatal stress related to maternal bereavement during pregnancy was associated with the risk of overweight in offspring during school age. METHODOLOGY/PRINCIPAL FINDINGS: We followed 65,212 children born in Denmark from 1970-1989 who underwent health examinations from 7 to 13 years of age in public or private schools in Copenhagen. We identified 459 children as exposed to prenatal stress, defined by being born to mothers who were bereaved by death of a close family member from one year before pregnancy until birth of the child. We compared the prevalence of overweight between the exposed and the unexposed. Body mass index (BMI) values and prevalence of overweight were higher in the exposed children, but not significantly so until from 10 years of age and onwards, as compared with the unexposed children. For example, the adjusted odds ratio (OR) for overweight was 1.68 (95% confidence interval [CI] 1.08-2.61) at 12 years of age and 1.63 (95% CI 1.00-2.61) at 13 years of age. The highest ORs were observed when the death occurred in the period from 6 to 0 month before pregnancy (OR 3.31, 95% CI 1.71-6.42 at age 12, and OR 2.31, 95% CI 1.08-4.97 at age 13). CONCLUSIONS/SIGNIFICANCE: Our results suggest that severe pre-pregnancy stress is associated with an increased risk of overweight in the offspring in later childhood

The impact of comorbidity and stage on ovarian cancer mortality: A nationwide Danish cohort study

<p>Abstract</p> <p>Background</p> <p>The incidence of ovarian cancer increases sharply with age, and many elderly patients have coexisting diseases. If patients with comorbidities are diagnosed with advanced stages, this would explain the poor survival observed among ovarian cancer patients with severe comorbidity. Our aims were to examine the prevalence of comorbidity according to stage of cancer at diagnosis, to estimate the impact of comorbidity on survival, and to examine whether the impact of comorbidity on survival varies by stage.</p> <p>Methods</p> <p>From the Danish Cancer Registry we identified 5,213 patients (> 15 years old) with ovarian cancer diagnosed from 1995 to 2003. We obtained information on comorbidities from the Danish National Hospital Discharge Registry. Vital status was determined through linkage to the Civil Registration System. We estimated the prevalence of comorbidity by stage and computed absolute survival and relative mortality rate ratios (MRRs) by comorbidity level (Charlson Index score 0, 1–2, 3+), using patients with Charlson Index score 0 as the reference group. We then stratified by stage and computed the absolute survival and MRRs according to comorbidity level, using patients with Charlson score 0 and localized tumour/FIGO I as the reference group. We adjusted for age and calendar time.</p> <p>Results</p> <p>Comorbidity was more common among patients with an advanced stage of cancer. One- and five-year survival was higher in patients without comorbidity than in patients with registered comorbidity. After adjustment for age and calendar time, one-year MRRs declined from 1.8 to 1.4 and from 2.7 to 2.0, for patients with Charlson scores 1–2 and 3+, respectively. After adjustment for stage, the MRRs further declined to 1.3 and 1.8, respectively. Five-year MRRs declined similarly after adjustment for age, calendar time, and stage. The impact of severe comorbidity on mortality varied by stage, particularly among patients with tumours with regional spread/FIGO-stages II and III.</p> <p>Conclusion</p> <p>The presence of severe comorbidity was associated with an advanced stage of ovarian cancer. Mortality was higher among patients with comorbidities and the impact of comorbidity varied by stage.</p

Maternal Postpartum Distress and Childhood Overweight

OBJECTIVE: We investigated associations between maternal postpartum distress covering anxiety, depression and stress and childhood overweight. METHODS: We performed a prospective cohort study, including 21,121 mother-child-dyads from the Danish National Birth Cohort (DNBC). Maternal distress was measured 6 months postpartum by 9 items covering anxiety, depression and stress. Outcome was childhood overweight at 7-years-of age. Multiple logistic regression analyses were performed and information on maternal age, socioeconomic status, pre-pregnancy BMI, gestational weight gain, parity, smoking during pregnancy, paternal BMI, birth weight, gestational age at birth, sex, breastfeeding and finally infant weight at 5 and 12 month were included in the analyses. RESULTS: We found, that postpartum distress was not associated with childhood risk of overweight, OR 1.00, 95%CI [0.98-1.02]. Neither was anxiety, depression, or stress exposure, separately. There were no significant differences between the genders. Adjustment for potential confounders did not alter the results. CONCLUSION: Maternal postpartum distress is apparently not an independent risk factor for childhood overweight at 7-years-of-age. However, we can confirm previous findings of perinatal determinants as high maternal pre-pregnancy BMI, and smoking during pregnancy being risk factors for childhood overweight

Risk of surgical site infection and efficacy of antibiotic prophylaxis: a cohort study of appendectomy patients in Thailand

BACKGROUND: No data currently exist about use of antibiotics to prevent surgical site infections (SSI) among patients undergoing appendectomy in Thailand. We therefore examined risk factors, use, and efficacy of prophylactic antibiotics for surgical site infection SSI among patients with uncomplicated open appendectomy. METHODS: From July 1, 2003 to June 30, 2004 we conducted a prospective cohort study in eight hospitals in Thailand. We used the National Nosocomial Infection Surveillance (NNIS) system criteria to identify SSI associated with appendectomy. We used logistic regression analysis to obtain relative risk estimates for predictors of SSI. RESULTS: Among 2139 appendectomy patients, we identified 26 SSIs, yielding a SSI rate of 1.2 infections/100 operations. Ninety-two percent of all patients (95% CI, 91.0–93.3) received antibiotic prophylaxis. Metronidazole and gentamicin were the two most common antibiotic agents, with a combined single dose administered in 39% of cases. In 54% of cases, antibiotic prophylaxis was administered for one day. We found that a prolonged duration of operation was significantly associated with an increased SSI risk. Antibiotic prophylaxis was significantly associated with a decreased risk of SSI regardless of whether the antibiotic was administered preoperatively or intraoperatively. Compared with no antibiotic prophylaxis, SSI relative risks for combined single-dose of metronidazole and gentamicin, one-day prophylaxis, and multiple-day antibiotic prophylaxis were 0.28 (0.09–0.90), 0.30 (0.11–0.88) and 0.32 (0.10–0.98), respectively. CONCLUSION: Single-dose combination of metronidazole and gentamicin seems sufficient to reduce SSIs in uncomplicated appendicitis patients despite whether the antibiotic was administered preoperatively or intraoperatively