Background and purpose Femoral neck fractures are considerably more common in patients on hemodialysis than in the general population. We determined the outcome of bipolar hemiarthroplasty for hip fracture in patients with long-term hemodialysis and compared it with that of a matched-paired group of patients with intact renal function.Methods We analyzed 26 bipolar hemiarthroplasties in 23 hemodialysed patients with a mean age of 56 (41–78) years who were followed for mean 3.6 (1–8) years. These cases were matched for age, sex, and BMI with 26 patients with femoral neck fractures and normal renal function. The mean follow-up time in the control group was 7 (5–10) years. As primary surgery for their femoral neck fracture, all patients had a bipolar hemiarthroplasty with a 28-mm metal-polyethylene internal articulation and a cemented stem.Results The mortality rate was 21% in the hemodialysed group and 4% in the control group (p = 0.005). The bipolar head migrated in 1 patient in the hemodialysed group but in none of the patients in the case-matched group. In the hemodialysed group, 8 stems migrated and 3 of these were revised, whereas in the control group 3 stems migrated and 2 were revised. The stem migration in the hemodialysed group was not preceded by the development of osteolysis or radiolucent lines at the bone-cement interface. The cumulative survival for prosthesis migration as endpoint was 44% at 5 years in the hemodialysed group and 96% in the control group (p = 0.03).Interpretation The main mode of failure of cemented bipolar hemiarthroplasties in hemodialysed patients is stem migration, due to failure of the bone-cement interface.

Research Highlights: This research provides a firm basis for understanding the improved aspen hybrid performance that aims at facilitating optimal clone selection for industrial application. Background and Objectives: Rapid growth and wood properties make aspen (Populus tremula L.) suitable for the production of pulp and paper. We assessed the potential of tree improvement through hybridization to enhance aspen productivity in northern Poland, and investigated the effects of Populus tremula hybridization with Populus tremuloides Michaux and Populus alba L. on the growth and cellulosic pulp properties for papermaking purposes. Materials and Methods: A common garden trial was utilized that included 15 hybrid aspen clones of P. tremula × P. tremuloides, four of P. tremula × P. alba, and one, previously tested P. tremula clone. Clones of P. tremula, plus trees from wild populations, were used as a reference. Tree height and diameter at breast height (DBH) were measured after growing seasons four through seven. At seven years of age, the three clones representing all species combinations were harvested, and their cellulosic pulp properties and paper sheet characteristics were assessed. Results: The clones from wild populations exhibited the poorest growth. In contrast, the clone ‘Wä 13′ (P. tremula × P. tremuloides) demonstrated the highest DBH, height, volume production, and mean annual increment (MAI) (25.4 m3 ha−1 year−1). The MAI ratio calculated for interspecific crosses ranged from 1.35- to 1.42-fold, higher than that for the P. tremula. Chemical properties of pulp, fiber morphology, and the physical properties of paper sheets were more desirable for interspecific hybrid clones than those for the pure P. tremula clone. Conclusions: The results indicated that plantations of hybrid aspen may constitute an important additional source of wood for pulp and paper products in Poland. Our findings further suggested that the standard rotation of these trees may be reduced from 40 to 20 years, increasing overall biomass yield and enhancing atmospheric carbon sequestration.

Introduction: Penile cancer is rare, and data on prognostic factors of the disease are scarce. The aim of the study was to assess prognostic factors in patients undergoing lymphadenectomy for penile cancer. Material and Methods: Ninety-eight men who underwent lymphadenectomy for penile cancer were enrolled in the study. Progression-free survival and overall survival were assessed. Results: Five-year progression-free survival and overall survival were 0.6651 (95% CI: 0.5151-0.7783) and 0.5516 (95% CI: 0.4412-0.6488), respectively. Multivariate analysis showed that the factors that reduce progression-free survival include delay of lymphadenectomy by more than 3 months after diagnosis (p = 0.045) and involvement of non-inguinal lymph nodes (N0 vs. affected lymph nodes other than superficial inguinal, p = 0.0004; superficial inguinal vs. others, p = 0.001). Factors deteriorating overall survival include high grade (G1 vs. G2, p = 0.0072, and G1 vs. G3, p = 0.0347), more than one lymph node affected (p = 0.001) and crossing the lymph node capsule (p = 0.034). Conclusions: The factors worsening the prognosis in patients with penile cancer after lymphadenectomy include delayed lymphadenectomy, involvement of lymph nodes other than the superficial inguinal, involvement of more than one lymph node, crossing the lymph node capsule, and high grade.

The aim of our research is to propose a method of rating companies which is based on efficiency measure given by Data Envelopment Analysis (DEA). Proper rating of borrowers is an essential requirement of PD estimation. The difficulty in DEA application is the selection of input and output from the set of indicators describing evaluated objects, which is usually based on expert knowledge. Therefore we apply random forests and gradient boosting to select financial indicators used by the DEA approach and to obtain a ranking of companies needed for PD estimation.

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The key demand for banks' economic capital methodology is to ensure that the model covers all relevant sources of risk in the right way. Operational risk models treat the arising losses as stochastic variables. One of the problems encountered in modeling is the need of taking into account correlations between events. It is possible to build models for correlated events based on copula functions. But the problem is that the losses are related to isolated events and simple applications of copulas are not allowed. The authors present a new algorithm that shows a modied application of copulas to calculating operational risk. The calculations were done on real data that allows for examining the correlation impact on risk measurement. As an additional evaluation of the algorithm a reference model based on the ParetoLévy copulas was used.

Credit risk models used in banks are based on probability models for occurrence of default. A vast class of the models used in practice (e.g., Credit Metrics) is based on the notion of intensity. In 1997 Jarrow applied Markov chain approach to analyze intensities. The key problem that arises is the selection of appropriate estimators. Within the Markov approach among the most frequently used estimators of a migration matrix are cohort and duration estimators. Migration matrices can also be obtained with help of statistical longitudinal models (GLMM) in which states (rating classes) in discrete time points are regarded as matched pairs. In this paper we compare Markov chain models and GLMM models and the influence of their application on bank portfolio evaluation.

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