Defining and Surveying Wireless Link Virtualization and Wireless Network Virtualization

Virtualization is a topic of great interest in the area of mobile and wireless communication systems. However, the term virtualization is used in an inexact manner which makes it difficult to compare and contrast work that has been carried out to date. The purpose of this paper is twofold. In the first place, this paper develops a formal theory for defining virtualization. In the second instance, this theory is used as a way of surveying a body of work in the field of wireless link virtualization, a subspace of wireless network virtualization. The formal theory provides a means for distinguishing work that should be classed as resource allocation as distinct from virtualization. It also facilitates a further classification of the representation level at which the virtualization occurs, which makes comparison of work more meaningful. This paper provides a comprehensive survey and highlights gaps in the research that make for fruitful future work

Photocatalytic properties of tin oxide and antimony-doped tin oxide nanoparticles

For the first time it is shown that N-doped SnO2 nanoparticles photocatalyze directly the polymerization of the C=C bonds of (meth)acrylates under visible light illumination. These radical polymerizations also occur when these particles are doped with Sb and when the surfaces of these particles are grafted with methacrylate (MPS) groups. During irradiation with visible or UV light the position and/or intensity of the plasmon band absorption of these nanoparticles are always changed, suggesting that the polymerization starts by the transfer of an electron from the conduction band of the particle to the (meth)acrylate C=C bond. By using illumination wavelengths with a very narrow band width we determined the influence of the incident wavelength of light, the Sb- and N-doping, and the methacrylate (MPS) surface grafting on the quantum efficiencies for the initiating radical formation (F) and on the polymer and particle network formation. The results are explained by describing the effects of Sb-doping, N-doping, and/or methacrylate surface grafting on the band gaps, energy level distributions, and surface group reactivities of these nanoparticles. N-doped (MPS grafted) SnO2 (Sb = 0%) nanoparticles are new attractive photocatalysts under visible as well as UV illumination

Breeding for improved welfare in pigs: a conceptual framework and its use in practice

Welfare of animals can be defined as the kind of feelings the environmental conditions bring about in the animals. These feelings depend on the needs of the animals and their degree of satisfaction. Needs of animals, and so their welfare, are partly genetically determined. Therefore, welfare can be changed by breeding. The aim of this study was to investigate how welfare of pigs under modern intensive farm conditions can be improved by genetic selection, with emphasis on the precise definition of the breeding goal and determination of the animal characteristics on which selection can be based in practice. The existing thermoregulation model was used to develop a conceptual framework that describes welfare of growing pigs and production sows with respect to each of their needs as a curvilinear function of the respective environmental conditions. The framework assumes that welfare in terms of feelings is reflected by the physiological and behavioural mechanisms the pig has to activate in order to cope with the various environmental conditions it encounters. Based on those physiological and behavioural responses to changing conditions, five welfare zones can be distinguished for each need. Breeding goals for welfare were defined in terms of the transition points between these welfare zones, such that future pigs would better cope with unfavourable or unfamiliar farming conditions, therewith quickening the domestication process, to some extent. However, as long as genetic parameters for these transition points are not available, more common welfare-related characteristics like temperament, stress resistance and robustness can be included in the breeding goal, as an alternative. For selection among potential breeding candidates, transition points between welfare zones can be determined in sib tests, thereby also collecting the data for estimating genetic parameters. As a cheaper alternative, breeding candidates could be tested under hard conditions and selected on their coping success. In addition, various behavioural tests and operant conditioning tests ( to test a pig's motivation to change its actual environment) can be carried out. Under common conditions on the farm, problems associated with coping (like incidences of diseases, injuries, and stereotypies) and/or other relevant traits ( e. g. saliva cortisol levels, longevity and even production traits) should be recorded routinely and used as selection index information. Selection for improved welfare should lead to more tolerant pigs that are better able to cope with possible unfavourable farm conditions by a more efficient use of the adaptation mechanisms they already possess. It should, however, not result in lowering husbandry standards. More research is needed to assess genetic correlations among various welfare aspects and with production traits to prevent undesired side effects in future populations of pigs

Efficient cDNA cloning by direct phenotypic correction of a mutant human cell line (HPRT-) using an Epstein-Barr virus derived cDNA expression vector.

Human cells are, in general, poor recipients of foreign DNA, which has severely hampered the cloning of genes by direct phenotypic correction of deficient human cell lines after DNA mediated gene transfer. In this communication a methodology is presented which largely circumvents this problems. The method relies on the use of a recently developed episomal Epstein-Barr-virus-derived cDNA expression vector (Belt et al. (1989) Gene 84, 407-417). The cloning of hypoxanthine phosphoribosyltransferase (HPRT) cDNA, corresponding to a low abundant mRNA in wild type cells is used as a model system. Size fractionated poly (A)+ RNA from wild type cells, which resulted in an approximately 10 fold enrichment in HPRT mRNA, was used to construct a cDNA library of 25,000 independent clones in the pECV25 vector. An HPRT deficient human cell line was transfected and subsequently selected with hygromycin B for DNA uptake. In a small scale experiment only 7000 hygromycin BR transfectants were sufficient to isolate 2 independent HATR clones which were shown to replicate episomes harbouring HPRT cDNA. The first insert had a 5' untranslated region (UTR) and a 3' UTR perfectly in agreement with published data. The second cDNA clone harboured an unusually long 5' UTR and a shorter 3' UTR due to alternative polyadenylation of the HPRT transcript which has not been previously recognized

Longitudinal relationship between albuminuria in infancy and childhood

Background: Mildly increased albuminuria is common in the general adult population and is a strong predictor for cardiovascular events, even in otherwise healthy individuals. The underlying pathophysiological process could be endothelial dysfunction. Previously, we reported that increased albuminuria can also be found in 2-year-olds from the general population. We hypothesized that some individuals have constitutionally higher levels of albuminuria, possibly as an expression of early or inborn endothelial dysfunction. The aim of this study is to evaluate longitudinal persistence of albuminuria from infancy into school age. Methods: In the population-based GECKO (Groningen Expert Center for Kids with Obesity) cohort, urine was collected from 816 children at the age of 2 years as well as 12 years (random urine and first morning void urine, respectively). We evaluated prevalence and persistence of increased albuminuria (U ACR ≥ 3 mg/mmol) at the two time points. Results: The prevalence of U ACR ≥ 3 mg/mmol at 2 and 12 years of age was 31.9% (95% CI 28.7–35.2) and 3.1% (95% CI 2.0–4.5), respectively. U ACR &lt; 3 mg/mmol at both 2 and 12 years of age was present in 540 children (66.2%). Only 9 children (3.5%) of the 260 children with an U ACR ≥ 3 mg/mmol at 2 years had an U ACR ≥ 3 mg/mmol at 12 years (p &lt; 0.001). Conclusion: Albuminuria in 2-year-olds does largely not persist until the age of 12, indicating that albuminuria at 2 years of age is not a marker for constitutional endothelial dysfunction in this cohort. Graphical abstract: [Figure not available: see fulltext.]</p

Structural changes in S. epidermidis biofilms after transmission between stainless steel surfaces

Transmission is a main route for bacterial contamination, involving bacterial detachment from a donor and adhesion to receiver surfaces. This work aimed to compare transmission of an extracellular polymeric substance (EPS) producing and a non-EPS producing Staphylococcus epidermidis strain from biofilms on stainless steel. After transmission, donor surfaces remained fully covered with biofilm, indicating transmission through cohesive failure in the biofilm. Counter to the numbers of biofilm bacteria, the donor and receiver biofilm thicknesses did not add up to the pre-transmission donor biofilm thickness, suggesting more compact biofilms after transmission, especially for non-EPS producing staphylococci. Accordingly, staphylococcal density per unit biofilm volume had increased from 0.20 to 0.52 μm(-3) for transmission of the non-EPS producing strain under high contact pressure. The EPS producing strain had similar densities before and after transmission (0.17 μm(-3)). This suggests three phases in biofilm transmission: (1) compression, (2) separation and (3) relaxation of biofilm structure to its pre-transmission density in EPS-rich biofilms

Prevalence and distribution of (micro)albuminuria in toddlers

Background. Microalbuminuria is common in the general adult population, with a prevalence of similar to 7%, and is an independent indicator of renal and cardiovascular risks. Whether albuminuria is acquired during life (as a result of hypertension/diabetes) or is congenital and already present at birth is unknown. We studied the prevalence of microalbuminuria in toddlers and compared the distribution of albuminuria with that of the general adult population. In addition, we looked for possible associations between microalbuminuria and antenatal, postnatal and maternal factors.Methods. The urinary albumin concentration (U-AC) was measured in 1352 children and the urinary albumin:creatinine ratio (U-ACR) in 1288 children from the Groningen Expert Center for Kids with Obesity (GECKO) Drenthe cohort (age range 20-40 months). Albuminuria distribution was compared with the albuminuria distribution in 40 854 participants of the general adult cohort of the Prevention of Renal and Vascular End stage Disease (PREVEND) study. Associations between albuminuria (expressed as U-AC and U-ACR) and antenatal, postnatal and maternal factors were tested with linear regression analysis.Results. The median U-AC in the GECKO study was 2.3 mg/L (5th-95th percentiles: 2.1-25.5) and in the PREVEND study it was 6.0 mg/L (2.3-28.6) (P distribution comparison 0.053). The prevalence of U-AC a parts per thousand yen 20 mg/L was 6.9% in the GECKO study and 7.8% in the PREVEND study (P = 0.195). The prevalence of U-ACR a parts per thousand yen 30 mg/g in the GECKO study was 23.4%. U-AC and U-ACR were lower in boys. U-AC was not associated with other determinants, but U-ACR was associated with age and gestational diabetes.Conclusions. The distribution of U-AC and the prevalence of U-AC &gt; 20 mg/L in toddlers and in the young general adult population are comparable. These findings suggest that microalbuminuria is a congenital condition that may predispose to a higher cardiovascular risk later in life.</p

Social media posts and online search behaviour as early-warning system for MRSA outbreaks

Background: Despite many preventive measures, outbreaks with multi-drug resistant micro-organisms (MDROs) still occur. Moreover, current alert systems from healthcare organizations have shortcomings due to delayed or incomplete notifications, which may amplify the spread of MDROs by introducing infected patients into a new healthcare setting and institutions. Additional sources of information about upcoming and current outbreaks, may help to prevent further spread of MDROs. The study objective was to evaluate whether methicillin-resistant Staphylococcus aureus (MRSA) outbreaks could be detected via social media posts or online search behaviour; if so, this might allow earlier detection than the official notifications by healthcare organizations. Methods: We conducted an exploratory study in which we compared information about MRSA outbreaks in the Netherlands derived from two online sources, Coosto for Social Media, and Google Trends for search behaviour, to the mandatory Dutch outbreak notification system (SO-ZI/AMR). The latter provides information on MDRO outbreaks including the date of the outbreak, micro-organism involved, the region/location, and the type of health care organization. Results: During the research period of 15 months (455 days), 49 notifications of outbreaks were recorded in SO-ZI/ AMR. For Coosto, the number of unique potential outbreaks was 37 and for Google Trends 24. The use of social media and online search behaviour missed many of the hospital outbreaks that were reported to SO-ZI/AMR, but detected additional outbreaks in long-term care facilities. Conclusions: Despite several limitations, using information from social media and online search behaviour allows rapid identification of potential MRSA outbreaks, especially in healthcare settings with a low notification compliance. When combined in an automated system with real-time updates, this approach might increase early discovery and subsequent implementation of preventive measures.EPI-Net COMBACTE-MAGNET project 115737Unión Europea FP7/2007–201

Treatment of stage I seminoma: is it time to change your practice?

At the plenary session of the 2008 annual meeting of the American Society of Clinical Oncology, updated results were presented from a large randomized phase III trial comparing adjuvant radiation therapy (RT) and one cycle of Carboplatin for the adjuvant treatment of Stage I seminoma. Results of this Medical Research Council (MRC) trial led its investigators to conclude that one cycle of carboplatin was equivalent in safety and efficacy and less toxic than RT. In this editorial, the trial's design, statistics, toxicity, and length of follow-up are discussed within the context of historical treatments of this disease. With a 1.3% increase in relapse rate (5.3% with carboplatin vs. 4.0% with radiation), a 3% or greater increase in relapse rate could not be excluded, the primary endpoint of the study. A decrease in second testicular germ cell tumors was observed, but was equivalent to the increase in relapse rate. Acute toxicity was generally less with carboplatin. However, the extent of late toxicity, including late second neoplasms, cannot be evaluated because of the short median follow-up. Carboplatin is not yet a standard of care. Surveillance-based strategies, including risk-adapted policies that limit RT to patients with the greatest likelihood of relapse remain prudent at this time