29 research outputs found
Default Risk
The hazard rate models used in recent bankruptcy literature assume censoring and default are two independent events, which means the censored company will eventually default. However we believe there will be a portion in the censored group that will be long-term survivors and we propose a mixture model of survivors and risky companies. Moreover this dissertation models the event and the timing of default incident at the same time. For the event of default and the timing of default we utilize a logistic regression. The results have justified the advantage of our model over the standard hazard rate models and proved its predictive power. The companies identified as high default risk by our model proved to deliver extremely low returns in the market
A consumer behavioural approach to food waste
Purpose
Food waste occurs in every stage of the supply chain, but the value-added lost to waste is the highest when consumers waste food. The purpose of this paper is to understand the food waste behaviour of consumers to support policies for minimising food waste.
Design/methodology/approach
Using the theory of planned behaviour (TPB) as a theoretical lens, the authors design a questionnaire that incorporates contextual factors to explain food waste behaviour. The authors test two models: base (four constructs of TPB) and extended (four constructs of TPB plus six contextual factors). The authors build partial least squares structural equation models to test the hypotheses.
Findings
The data confirm significant relationships between food waste and contextual factors such as motives, financial attitudes, planning routines, food surplus, social relationships and Ramadan.
Research limitations/implications
The data comes from an agriculturally resource-constrained country: Qatar.
Practical implications
Food waste originating from various causes means more food should flow through the supply chains to reach consumers’ homes. Contextual factors identified in this work increase the explanatory power of the base model by 75 per cent.
Social implications
Changing eating habits during certain periods of the year and food surplus have a strong impact on food waste behaviour.
Originality/value
A country is considered to be food secure if it can provide its citizens with stable access to sufficient, safe and nutritious food. The findings and conclusions inform and impact upon the development of food waste and food security policies
Parathyroid hormone and phosphate homeostasis in patients with Bartter and Gitelman syndrome:an international cross-sectional study
Background:Small cohort studies have reported high parathyroid hormone (PTH) levels in patients with Bartter syndrome and lower serum phosphate levels have anecdotally been reported in patients with Gitelman syndrome. In this cross-sectional study, we assessed PTH and phosphate homeostasis in a large cohort of patients with salt-losing tubulopathies. Methods:Clinical and laboratory data of 589 patients with Bartter and Gitelman syndrome were provided by members of the European Rare Kidney Diseases Reference Network (ERKNet) and the European Society for Paediatric Nephrology (ESPN). Results:A total of 285 patients with Bartter syndrome and 304 patients with Gitelman syndrome were included for analysis. Patients with Bartter syndrome type I and II had the highest median PTH level (7.5 pmol/L) and 56% had hyperparathyroidism (PTH >7.0 pmol/L). Serum calcium was slightly lower in Bartter syndrome type I and II patients with hyperparathyroidism (2.42 versus 2.49 mmol/L; P = .038) compared to those with normal PTH levels and correlated inversely with PTH (rs −0.253; P = .009). Serum phosphate and urinary phosphate excretion did not correlate with PTH. Overall, 22% of patients had low serum phosphate levels (phosphate—standard deviation score < −2), with the highest prevalence in patients with Bartter syndrome type III (32%). Serum phosphate correlated with tubular maximum reabsorption of phosphate/glomerular filtration rate (TmP/GFR) (rs 0.699; P < .001), suggesting renal phosphate wasting. Conclusions:Hyperparathyroidism is frequent in patients with Bartter syndrome type I and II. Low serum phosphate is observed in a significant number of patients with Bartter and Gitelman syndrome and appears associated with renal phosphate wasting.</p
Parathyroid hormone and phosphate homeostasis in patients with Bartter and Gitelman syndrome:an international cross-sectional study
Background:Small cohort studies have reported high parathyroid hormone (PTH) levels in patients with Bartter syndrome and lower serum phosphate levels have anecdotally been reported in patients with Gitelman syndrome. In this cross-sectional study, we assessed PTH and phosphate homeostasis in a large cohort of patients with salt-losing tubulopathies. Methods:Clinical and laboratory data of 589 patients with Bartter and Gitelman syndrome were provided by members of the European Rare Kidney Diseases Reference Network (ERKNet) and the European Society for Paediatric Nephrology (ESPN). Results:A total of 285 patients with Bartter syndrome and 304 patients with Gitelman syndrome were included for analysis. Patients with Bartter syndrome type I and II had the highest median PTH level (7.5 pmol/L) and 56% had hyperparathyroidism (PTH >7.0 pmol/L). Serum calcium was slightly lower in Bartter syndrome type I and II patients with hyperparathyroidism (2.42 versus 2.49 mmol/L; P = .038) compared to those with normal PTH levels and correlated inversely with PTH (rs −0.253; P = .009). Serum phosphate and urinary phosphate excretion did not correlate with PTH. Overall, 22% of patients had low serum phosphate levels (phosphate—standard deviation score < −2), with the highest prevalence in patients with Bartter syndrome type III (32%). Serum phosphate correlated with tubular maximum reabsorption of phosphate/glomerular filtration rate (TmP/GFR) (rs 0.699; P < .001), suggesting renal phosphate wasting. Conclusions:Hyperparathyroidism is frequent in patients with Bartter syndrome type I and II. Low serum phosphate is observed in a significant number of patients with Bartter and Gitelman syndrome and appears associated with renal phosphate wasting.</p
Contextual factors affecting food security : a behavioural framework
Globalised distribution networks together with advances in information and communication technologies as well as transport routes and infrastructure have led to long and complex food supply chains where the physical footprint of production operations are located far from the points of consumption. This increasing complexity exacerbated by surges in global food prices due to low levels of production in grain-producing nations and the rising costs of oil, fertilizers, and transportation, is raising concerns about food security in many countries, especially those that rely on food imports to feed their population. On the other hand, several academic challenges associated with food security comprise unpacking this multi-faceted concept and finding ways to improve it. In fact, food security is at the top of the agenda in countries with relatively low capacity to be self-sustaining in food. An example is Qatar, which consists of low, barren plains covered with sand and subject to intense heat during dry seasons. Another relevant aspect for Qatar is the annual population growth of 2.87% (WorldBank, 2017), which is above the average population growth in the Gulf Cooperation Council (GCC) countries in the region. With increasing population and food provision depending on imports that comprise more than 90% of the food consumed in Qatar, it is not a surprise that food security is a top priority. This paper is a research outcome of the SAFE-Q Project, which aims to contribute to food security efforts in Qatar with the overarching research idea of a holistic approach to food distribution, food consumption, and food waste
Isolated Vitamin D Deficiency Is Not Associated with Nonthyroidal Illness Syndrome, but with Thyroid Autoimmunity
Aim. This study aimed to compare thyroid functions, thyroid autoantibodies, and the existence of nonthyroidal illness syndrome (NTIS) according to vitamin D level. Materials and Methods. The study included age- and BMI-matched healthy volunteers with and without vitamin D deficiency. In addition, the nonthyroidal illness syndrome status was evaluated. Results. Anti-TPO positivity was significantly more common in those with severe and moderate vitamin D deficiency, as compared to those with a normal 25(OH)D level. Furthermore, TSH levels were significantly lower in those with severe and moderate vitamin D deficiency than in those with a normal 25(OH)D level. In addition, there was a significant weak inverse correlation between anti-TPO positivity and the 25(OH)D level and a positive correlation between the TSH level and 25(OH)D level. Only 1 thyroid function test result was compatible with NTIS among the participants with moderate vitamin D deficiency; therefore the difference was not significant. Conclusions. The prevalence of thyroid autoantibody positivity was higher in those with severe and moderate vitamin D deficiency than in those with a normal 25(OH)D level. Additional large-scale studies must be conducted to determine if vitamin D deficiency plays a causal role in the pathogenesis of Hashimoto's thyroiditis and NTIS.PubMedScopu
Retrospective evaluation of the contribution of radiotherapy to survival in breast cancer treatment with propensity score based on stage and subgroup
Abstract Background Breast cancer has been a disease in which treatment strategy has changed over time under the influence of different hypotheses and evidence for more than a century. We analyzed the contribution of radiotherapy to disease-free survival and overall survival by classifying according to stage, 1–3 lymph node involvement, and molecular subgroups. Methods Following the approval of the Institutional Review Board, records of patients with breast cancer who were admitted to University School of Medicine Departments of Radiation Oncology and Medical Oncology between July 1999 and December 2020 were reviewed. Using data propensity score matching was performed between the groups that did and did not receive radiotherapy using an optimal matching algorithm (optimum, 1:1). Disease-free survival and overall survival after propensity score matching were calculated using the Kaplan-Meier method. Univariate and multivariate Cox regression analysis was used to estimate hazard ratios. Results In the radiotherapy and non-radiotherapy groups, disease-free survival was 257.42 ± 5.46 (246.72- 268.13), 208,96 ± 8,15 (192,97–224,94) months respectively, (p = < 0.001), overall survival was 272,46 ± 8,68 (255,43–289,49), 219,05 ± 7,32 (204,70–233,41) months respectively (p = .002). We compared the 19 N1 patient groups who received radiotherapy with the 19 patients who did not receive radiotherapy and calculated the disease-free survival times was 202,21 ± 10,50 (181,62–222,79) and 148,82 ± 24,91 (99,99–197,65) months respectively (p = .011) and overall survival times was 200,85 ± 12,79 (175,77–225,92) and 166,90 ± 20,39 (126,93–206,82) months respectively (p = .055). We examined disease-free survival and overall survival times in both groups according to Luminal A, Luminal B, TNBC, and HER2-enriched subgroups. In the Luminal B subgroup, the disease-free survival duration in the groups receiving radiotherapy and not receiving radiotherapy was 264.83 ± 4.95 (255.13-274.54) and 187.09 ± 11.06 (165.41-208.78) months (p < .001), and overall survival times were 252.29 ± 10.54 (231.62-272.97) and 197.74 ± 9.72 (178.69–216.80) months (p = .001) respectively. Conclusions Thanks to studies proving that RT increases long-term survival rates in breast cancer as a result of reducing locoregional recurrence and systemic metastasis rates, it has been understood that the spectrum hypothesis is the hypothesis that most accurately describes breast cancer to date. We found that patients with Luminal B invasive breast cancer benefited significantly more from RT compared to other subgroups