Bootstrapping the economy -- a non-parametric method of generating consistent future scenarios

The fortune and the risk of a business venture depends on the future course of the economy. There is a strong demand for economic forecasts and scenarios that can be applied to planning and modeling. While there is an ongoing debate on modeling economic scenarios, the bootstrapping (or resampling) approach presented here has several advantages. As a non-parametric method, it directly relies on past market behaviors rather than debatable assumptions on models and parameters. Simultaneous dependencies between economic variables are automatically captured. Some aspects of the bootstrapping method require additional modeling: choice and ransformation of the economic variables, arbitrage-free consistency, heavy tails of distributions, serial dependence, trends and mean reversion. Results of a complete economic scenario generator are presented, tested and discussed.economic scenario generator (ESG); asset-liability management (ALM); bootstrapping; resampling; simulation; Monte-Carlo simulation; non-parametric model; yield curve model

Inhibition of iodine organification and regulation of follicular size in rat thyroid tissue in vitro

The factors mediating the accumulation of thyroglobulin are of great importance to the understanding of the pathogenesis of human and experimentally induced colloid goiters. To elucidate further the underlying cellular mechanism, thyroid fragments from newborn rats were incorporated into semisolid alginate beads and were cultured as three-dimensional organoids for up to 21 d. In five parallel cultures, the medium contained either no supplements (group A), Nal (group B), thyroid-stimulating hormone (TSH) (group C), Nal plus TSH in the same concentrations as B and C (group D), or Nal and TSH (as in group D) plus methimazole (MMI, group E). The thyroid organoids maintained morphological intergrity, functional activity, and ability to proliferate in vitro. Addition of iodine to the cultures significantly increased mean (±SEM) follicular diameters from 19.5±0.7 μm in controls to 33.9±2.2 μm (p<0.0001) when Nal was added alone (group B), and 30.4±1.7 μm (p<0.0001) when combined with TSH (group D). The effect of Nal on follicular size was abolished by MMI (group E, follicular diameter 23.5±1.3 μm). The results presented support the recent finding, using a rat colloid goiter model, that not only TSH but also iodine organification or its inhibition are important factors in modulating follicular morpholog

Extended Resection for Thyroid Disease has Less Operative Morbidity than Limited Resection

Background: Theodor Kocher, surgeon and Nobel laureate, has influenced thyroid surgery all over the world: his treatment for multinodular goiter—subtotal thyroidectomy—has been the "Gold Standard” for more than a century. However, based on a new understanding of molecular growth mechanisms in goitrogenesis, we set out to evaluate if a more extended resection yields better results. Methods: Four thousand three hundred and ninety-four thyroid gland operations with 5,785 "nerves at risk” were prospectively analyzed between 1972 and 2002. From 1972 to 1990, the limited Kocher resections were performed, and from 1991 to 2002 a more radical resection involving at least a hemithyroidectomy was performed. Results: The incidence of postoperative nerve palsy was 3.6%; in the first study period and 0.9%; in the second (P<0.001, Fisher's exact). Postoperative hypoparathyroidism decreased from 3.2%; in the first period to 0.64%; in the second (P<0.01). The rate of reoperation for recurrent disease was 11.1%; from 1972 to 1990 and 8.5%; from 1991 to 2002 (P<0.01). Conclusions: Extended resection for multinodular goiter not only significantly reduced morbidity, but also decreased the incidence of operations for recurrent disease. Our findings in a large cohort corroborate the suggestions that Kocher's approach should be replaced by a more radical resection, which actually was his original intention more than 130years ag

Bootstrapping the economy -- a non-parametric method of generating consistent future scenarios

The fortune and the risk of a business venture depends on the future course of the economy. There is a strong demand for economic forecasts and scenarios that can be applied to planning and modeling. While there is an ongoing debate on modeling economic scenarios, the bootstrapping (or resampling) approach presented here has several advantages. As a non-parametric method, it directly relies on past market behaviors rather than debatable assumptions on models and parameters. Simultaneous dependencies between economic variables are automatically captured. Some aspects of the bootstrapping method require additional modeling: choice and ransformation of the economic variables, arbitrage-free consistency, heavy tails of distributions, serial dependence, trends and mean reversion. Results of a complete economic scenario generator are presented, tested and discussed

Lymphom der Prostata - Diagnose auf den "zweiten Stich"

Zusammenfassung: Hintergrund:: Maligne Lymphome der Prostata sind eine klinische Rarität. In der Literatur werden insgesamt etwa 165 Fälle beschrieben, in denen ein primäres Lymphom oder eine sekundäre Infiltration der Prostata durch ein Lymphom vorlag. Fallbeschreibung:: Berichtet wird der Fall eines 59-jährigen Patienten mit einer unscharf begrenzten Raumforderung im Bereich der Prostata bei normalem prostataspezifischem Antigen (PSA), einer Wirbelkörperfraktur und bilateralen Nebennierenvergrößerungen. Eine zweizeitige Prostatastanzbiopsie erbrachte die Diagnose eines diffus-großzelligen B-Zell-Non-Hodgkin-Lymphoms. Weitere Staginguntersuchungen ergaben Anhaltspunkte für das Vorliegen eines epiduralen Befalls. Es wurde eine Polychemotherapie inklusive intrathekaler Applikation initiiert, unter der sich die Lymphommanifestationen bei einem ersten Zwischenstaging nach vier Zyklen deutlich zurückgebildet hatten. Nach weiteren zwei Zyklen R-CHOP zeigte ein CT zwar noch ein kleines Weichteilplus in der Prostataloge, im anschließenden PET-CT war jedoch kein vitales Lymphomgewebe mehr nachweisbar (komplette Remission). Schlussfolgerung:: Bei einer Raumforderung im Bereich der Prostata muss neben einem Prostatakarzinom als weitaus häufigste Tumorentität auch an ein solitäres Lymphom oder eine Infiltration der Prostata bei generalisiertem Lymphom gedacht werden, insbesondere bei einem normalen PS

Osteoporosis case finding in the general practice: phalangeal radiographic absorptiometry with and without risk factors for osteoporosis to select postmenopausal women eligible for lumbar spine and hip densitometry

Mass screening for osteoporosis using DXA measurements at the spine and hip is presently not recommended by health authorities. Instead, risk factor questionnaires and peripheral bone measurements may facilitate the selection of women eligible for axial bone densitometry. The aim of this study was to validate a case finding strategy for postmenopausal women who would benefit most from subsequent DXA measurement by using phalangeal radiographic absorptiometry (RA) alone or in combination with risk factors in a general practice setting. The sensitivity and specificity of this strategy in detecting osteoporosis (T-score ≤2.5SD at the spine and/or the hip) were compared with those of the current reimbursement criteria for DXA measurements in Switzerland. Four hundred and twenty-three postmenopausal women with one or more risk factors for osteoporosis were recruited by 90 primary care physicians who also performed the phalangeal RA measurements. All women underwent subsequent DXA measurement of the spine and the hip at the Osteoporosis Policlinic of the University Hospital of Berne. They were allocated to one of two groups depending on whether they matched with the Swiss reimbursement conditions for DXA measurement or not. Logistic regression models were used to predict the likelihood of osteoporosis versus "no osteoporosis” and to derive ROC curves for the various strategies. Differences in the areas under the ROC curves (AUC) were tested for significance. In women lacking reimbursement criteria, RA achieved a significantly larger AUC (0.81; 95% CI 0.72-0.89) than the risk factors associated with patients' age, height and weight (0.71; 95% C.I. 0.62-0.80). Furthermore, in this study, RA provided a better sensitivity and specificity in identifying women with underlying osteoporosis than the currently accepted criteria for reimbursement of DXA measurement. In the Swiss environment, RA is a valid case finding tool for patients with risk factors for osteoporosis, especially for those who do not qualify for DXA reimbursemen

Risk Factors Promoting Hypertensive Crises: Evidence From a Longitudinal Study

Background Current knowledge about risk factors promoting hypertensive crisis originates from retrospective data. Therefore, potential risk factors of hypertensive crisis were assessed in a prospective longitudinal study. Methods Eighty-nine patients of the medical outpatient unit at the University Hospital of Bern (Bern, Switzerland) with previously diagnosed hypertension participated in this study. At baseline, 33 potential risk factors were assessed. All patients were followed-up for the outcome of hypertensive crisis. Cox regression models were used to detect relationships between risk factors and hypertensive crisis (defined as acute rise of systolic blood pressure (BP) ≥200mmHg and/or diastolic BP ≥120mmHg). Results The mean duration of follow-up was 1.6 ± 0.3 years (range 1.0-2.4 years). Four patients (4.5%) were lost to follow-up. Thirteen patients (15.3%) experienced hypertensive crisis during follow-up. Several potential risk factors were significantly associated with hypertensive crisis: female sex, higher grades of obesity, the presence of a hypertensive or coronary heart disease, the presence of a somatoform disorder, a higher number of antihypertensive drugs, and nonadherence to medication. As measured by the hazard ratio, nonadherence was the most important factor associated with hypertensive crisis (hazard ratio 5.88, 95% confidence interval 1.59-21.77, P < 0.01). Conclusions This study identified several potential risk factors of hypertensive crisis. Results of this study are consistent with the hypothesis that improvement of medical adherence in antihypertensive therapy would help to prevent hypertensive crises. However, larger studies are needed to assess potential confounding, other risk factors and the possibility of interaction between predictor

Fundamental movement skills in relation to weekday and weekend physical activity in preschool children.

OBJECTIVES: To examine associations between fundamental movement skills and weekday and weekend physical activity among preschool children living in deprived communities. DESIGN: Cross-sectional observation study. METHODS: Six locomotor skills and 6 object-control skills were video-assessed using The Children's Activity and Movement in Preschool Study Motor Skills Protocol. Physical activity was measured via hip-mounted accelerometry. A total of 99 children (53% boys) aged 3-5 years (M 4.6, SD 0.5) completed all assessments. Multilevel mixed regression models were used to examine associations between fundamental movement skills and physical activity. Models were adjusted for clustering, age, sex, standardised body mass index and accelerometer wear time. RESULTS: Boys were more active than girls and had higher object-control skill competency. Total skill score was positively associated with weekend moderate-to-vigorous physical activity (p=0.034) but not weekday physical activity categories (p>0.05). When subdomains of skills were examined, object-control skills was positively associated with light physical activity on weekdays (p=0.008) and with light (p=0.033), moderate-to-vigorous (p=0.028) and light- and moderate-to-vigorous (p=0.008) physical activity at weekends. Locomotor skill competency was positively associated with moderate-to-vigorous physical activity on weekdays (p=0.016) and light physical activity during the weekend (p=0.035). CONCLUSIONS: The findings suggest that developing competence in both locomotor and object-control skills may be an important element in promoting an active lifestyle in young children during weekdays and at weekends