Consistency of Kernel Estimators of Heteroscedastic and Autocorrelated Covariance Matrices

Conditions are derived for the consistency of kernel estimators of the covariance matrix of a sum of vectors of dependent heterogeneous random variables, which match those of the currently best-known conditions for the central limit theorem, as required for a unified theory of asymptotic inference. These include finite moments of order no more than 2 + for > 0, trending variances, and variables which are near-epoch dependent on a mixing process, but not necessarily mixing. The results are also proved for the case of sample-dependent bandwidths.kernel estimator;matrices

Differences between physicians in the likelihood of referral and acceptance of elderly patients for dialysis-influence of age and comorbidity

BACKGROUND: Incidence of dialysis in elderly patients in the Netherlands is low compared to other countries. This study aims to assess the impact of patients' age and comorbidity on the likelihood of referral and acceptance of patients for dialysis and whether this is affected by physician characteristics. METHODS: A vignette study was performed among 209 primary care physicians, 162 non-nephrology specialists and 20 nephrologists working in the north of the Netherlands. Physicians were offered six vignettes concerning case-reports of patients with end-stage renal disease (ESRD) and varying comorbidities or circumstances and asked about the likelihood of referral/acceptance of the patient in the given circumstances. RESULTS: The likelihood of referral within groups of physicians varied widely, especially within the group of primary care physicians and non-nephrology specialists, but was not affected by characteristics of physicians. The likelihood of referral or acceptance of patients for dialysis depended on the patient's age, and type and severity of comorbidity. In general, primary care physicians and non-nephrology specialists were less likely to refer than nephrologists were to accept. Differences within and between groups of physicians were larger for 80- than for 65-year-old patients, and for patients with less severe shortness of breath and cognitive impairments and more severe diabetes and social impairments. Hardly any differences were found for patients with cancer. CONCLUSION: Patients' age and comorbidities affect the likelihood of referral. Differences between groups of physicians suggest that there is insufficient agreement on the extent to which these factors should affect the referral/acceptance of patients for dialysis. These findings underline the need for more research into circumstances under which patients might benefit from dialysis. Guidelines should be developed to improve the referral of elderly and less healthy patients

FISH mapping and molecular organization of the major repetitive sequences of tomato

This paper presents a bird's-eye view of the major repeats and chromatin types of tomato. Using fluorescence in-situ hybridization (FISH) with Cot-1, Cot-10 and Cot-100 DNA as probes we mapped repetitive sequences of different complexity on pachytene complements. Cot-100 was found to cover all heterochromatin regions, and could be used to identify repeat-rich clones in BAC filter hybridization. Next we established the chromosomal locations of the tandem and dispersed repeats with respect to euchromatin, nucleolar organizer regions (NORs), heterochromatin, and centromeres. The tomato genomic repeats TGRII and TGRIII appeared to be major components of the pericentromeres, whereas the newly discovered TGRIV repeat was found mainly in the structural centromeres. The highly methylated NOR of chromosome 2 is rich in [GACA](4), a microsatellite that also forms part of the pericentromeres, together with [GA](8), [GATA](4) and Ty1-copia. Based on the morphology of pachytene chromosomes and the distribution of repeats studied so far, we now propose six different chromatin classes for tomato: (1) euchromatin, (2) chromomeres, (3) distal heterochromatin and interstitial heterochromatic knobs, (4) pericentromere heterochromatin, (5) functional centromere heterochromatin and (6) nucleolar organizer regio

Управління як соціальна дія

У статті аналізується необхідність системного розгляду управління як різновиду соціальної дії, наголошується на необхідності методологічного забезпечення управлінської діяльності, для чого мають залучатися новітні парадигми останнього часу, такі як системологія і синергетика. Управління постає як цілепокладальна, цілераціональна галузь буття соціуму.В статье анализируется необходимость системного рассмотрения управления как вида социального действия, акцентируется внимание на необходимости методологического обеспечения управленческой деятельности, для чего должны привлекаться новейшие парадигмы современности, такие как системология и синергетика. Управление предстает как целеполагающая, целерациональная отрасть бытия социума.This article describes the need of systemology consideration of the management as social action, attention is directed on the need of metodological supply of manage action where newest last time paradigm, such as systemology and synergetics are involved. Management becomes as object rational and object related branch of society being

Prolonged persistence of bovine herpesvirus in small cattle herds: a model-based analysis

Herpesviruses can remain dormant in once-infected hosts and, upon reactivation, cause such hosts to become infectious. This phenomenon of latency and reactivation may enable herpesviruses to persist for a long time in small host populations. To quantify the effect of reactivation on persistence, the time to extinction of bovine herpesvirus type 1 (BHV-1) in small cattle populations was calculated. For realistic parameter values the mean time to extinction is already more than 100 years in a population of 10 animals. In a population of 20 animals the time to extinction is approximately 2000 years. The effects of vaccination on persistence were also studied, revealing that continued vaccination of the whole population could result in much faster eradication. For instance, in an isolated herd of 20 animals BHV-1 could be eradicated in 44 years

Health-related quality of life and anemia in hospitalized patients with heart failure

AbstractBackgroundAnemia is a serious and highly prevalent co-morbidity in chronic heart failure (HF) patients. Its influence on health-related quality of life (HR-QoL) has rarely been studied, and no data is available regarding the role it plays in hospitalized HF patients.MethodsBaseline data from the COACH study (Coordinating study evaluating Outcomes of Advising and Counselling in Heart Failure) were used. HR-QoL was assessed by means of generic and disease-specific questionnaires. Analyses were performed using ANOVA and ANCOVA, with covariates of age, gender, eGFR, diabetes, and NYHA class.ResultsIn total, 1013 hospitalized patients with a mean age of 71 (SD 11) years were included; 70% of these patients had no anemia (n=712), 14% had mild anemia (n=141), and 16% had moderate-to-severe anemia (n=160). Independent associations were found between anemia and physical functioning (p=0.019), anemia and role limitations due to physical functioning (p=0.002), anemia and general health (p=0.024), and anemia and global well-being (p=0.003).ConclusionIn addition to the burden of HF itself, anemia is an important factor which influences HR-QoL in hospitalized HF patients, and one that is most pronounced in the domain related to physical functioning and general health

The Economics and Politics of Contracting out with the Private Sector: Evidence from the US Transit Industry

The paper studies contracting practices in the US transit industry. It employs the methods of transaction cost economics and public choice theory to develop an empirical model of bus contracting in the US transit industry. The empirical results shed light on why transit services in the US remain largely public, despite many attempts to introduce competition by contracting out services to the private sector. The results show that the decision by transit agencies to contract out with the private sector is constrained by the transaction costs of contracting and the institutional and subsidy arrangements that govern the transit industry in the US. Services that require idiosyncratic investments to provide large densities of passengers are less likely to be contracted out than those services that are provided using standard, small vehicles. Similarly, increases in federal subsidies and dedicated subsidies are found to discourage contracting out with the private sector. On the other hand, increases in state and local subsidies, other things being equal, encourage contracting. Agencies that have high labor costs –– indicating strong labor unions –– are less likely to contract out. In light of these findings, the paper concludes that piecemeal contracting out of services is not likely to increase the role of the private sector in the provision of public transit services. Structures of subsidies and federal arrangements creates intertwined incentives that discourage contracting by transit agencies, thus foiling the attempts to increase efficiencies by establishing competition for transit markets.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Feasibility of rigid 3D image registration of high-resolution peripheral quantitative computed tomography images of healing distal radius fractures

For accurate analysis of bone formation and resorption during fracture healing, correct registration of follow-up onto baseline image is required. A per-fragment approach could improve alignment compared to standard registration based on the whole fractured region. In this exploratory study, we tested the effect of fragment size and displacement on a per-fragment registration, and compared the results of this per-fragment registration to the results of the standard registration in two stable fractures and one unstable fracture. To test the effect of fragment size and displacement, high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of three unfractured radii were divided into subvolumes. Different displacements in x-, y, or z-direction or rotations around each axis were applied, and each subvolume was registered onto the initial volume to realign it. Next, registration of follow-up onto baseline scan was performed in two stable and one unstable fracture. After coarsely aligning the follow-up onto the baseline scan, a more accurate registration was performed of the whole fracture, i.e. the standard registration, and of each fracture fragment separately, i.e. per-fragment registration. Alignment was checked using overlay images showing baseline, follow-up and overlap between these scans, and by comparing correlation coefficients between the standard and per-fragment registration. Generally, subvolumes as small as 300 mm3 that were displaced up to 0.82 mm in x- or y-, or up to 1.64 mm in z-direction could be realigned correctly. For the fragments of all fractures, correlation coefficients were higher after per-fragment registration compared to standard registration. Most improvement was found in the unstable fracture and one fragment of the unstable fracture did not align correctly. This exploratory study showed that image registration of individual subvolumes, such as fracture fragments, is feasible in both stable and unstable fractures, and leads to better alignment of these fragments compared to an approach that is based on registration using the whole fractured region. This result is promising for additional analysis of bone formation and resorption in HR-pQCT studies on fracture healing