Pairs of Bloch electrons and magnetic translation groups

A product of irreducible representations of magnetic translation group is considered. It leads to irreducible representations which were previously rejected as nonphysical. A very simple example indicates a possible application of these representations. In particular, they are important in descriptions of pairs of electrons in a magnetic field and a periodic potential. The periodicity of some properties with respect to the charge of a particle is briefly discussed.Comment: 4 pages, RevTex. Latex2.09, amsfont

Iisy: hybrid in-network classification using programmable switches

The soaring use of machine learning leads to increasing processing demands. As data volume keeps growing, providing classification services with good machine learning performance, high throughput, low latency, and minimal equipment overheads becomes a challenge. Offloading machine learning tasks to network switches can be a scalable solution to this problem, providing high throughput and low latency. However, network devices are resource constrained, and lack support for machine learning functionality. In this paper, we introduce IIsy - a novel mapping tool of machine learning classification models to off-the-shelf switches. Using an efficient encoding algorithm, IIsy enables fitting a range of classification models on switches, coexisting with standard switch functionality. To overcome resource constraints, IIsy adopts a hybrid approach for ensemble models, running a small model on a switch and a large model on the backend. The evaluation shows that IIsy achieves near-optimal classification results, within minimum resource overheads, and while reducing the load on the backend by 70% for data-intensive use cases

Fire retardant action of mineral fillers

Endothermically decomposing mineral fillers, such as aluminium or magnesium hydroxide, magnesium carbonate, or mixed magnesium/calcium carbonates and hydroxides, such as naturally occurring mixtures of huntite and hydromagnesite are in heavy demand as sustainable, environmentally benign fire retardants. They are more difficult to deploy than the halogenated flame retardants they are replacing, as their modes of action are more complex, and are not equally effective in different polymers. In addition to their presence (at levels up to 70%), reducing the flammable content of the material, they have three quantifiable fire retardant effects: heat absorption through endothermic decomposition; increased heat capacity of the polymer residue; increased heat capacity of the gas phase through the presence of water or carbon dioxide. These three contributions have been quantified for eight of the most common fire retardant mineral fillers, and the effects on standard fire tests such as the LOI, UL 94 and cone calorimeter discussed. By quantifying these estimable contributions, more subtle effects, which they might otherwise mask, may be identified

Current driven switching of magnetic layers

The switching of magnetic layers is studied under the action of a spin current in a ferromagnetic metal/non-magnetic metal/ferromagnetic metal spin valve. We find that the main contribution to the switching comes from the non-equilibrium exchange interaction between the ferromagnetic layers. This interaction defines the magnetic configuration of the layers with minimum energy and establishes the threshold for a critical switching current. Depending on the direction of the critical current, the interaction changes sign and a given magnetic configuration becomes unstable. To model the time dependence of the switching process, we derive a set of coupled Landau-Lifshitz equations for the ferromagnetic layers. Higher order terms in the non-equilibrium exchange coupling allow the system to evolve to its steady-state configuration.Comment: 8 pages, 2 figure. Submitted to Phys. Rev.

Getting evidence into policy: The need for deliberative strategies?

Getting evidence into policy is notoriously difficult. In this empirical case study we used document analysis and key informant interviews to explore the Australian federal government’s policy to implement a national bowel cancer screening programme, and the role of evidence in this policy. Our analysis revealed a range of institutional limitations at three levels of national government: within the health department, between government departments, and across the whole of government. These limitations were amplified by the pressures of the 2004 Australian federal election campaign. Traditional knowledge utilisation approaches, which rely principally on voluntarist strategies and focus on the individual, rather than the institutional level, are often insufficient to ensure evidence-based implementation. We propose three alternative models, based on deliberative strategies which have been shown to work in other settings: review of the evidence by a select group of experts whose independence is enshrined in legislation and whose imprimatur is required before policy can proceed; use of an advisory group of experts who consult widely with stakeholders and publish their review findings; or public discussion of the evidence by the media and community groups who act as more direct conduits to the decision-makers than researchers. Such deliberative models could help overcome the limitations on the use of evidence by embedding public review of evidence as the first step in the institutional decision-making processes. Highlights  Achieving evidence-based policy implementation is much harder than the rhetoric suggests.  Our case study showed traditional voluntarist approaches are not enough to overcome institutional filtering of the evidence.  Deliberative strategies open up the decision-making processes to greater expert and public scrutiny.  Our framework illustrates the potential for deliberative strategies to increase the relative weight of evidence in policy.  This article challenges researchers and policy-makers to acknowledge and address the institutional context of decision-making. Keywords: Australia; Health policy; Decision-making; Evidence; Knowledge utilisation; Bowel cancer; Screening; DeliberativeNHMR

Challenges in measuring nitrogen isotope signatures in inorganic nitrogen forms: An interlaboratory comparison of three common measurement approaches

Rationale Stable isotope approaches are increasingly applied to better understand the cycling of inorganic nitrogen (Ni) forms, key limiting nutrients in terrestrial and aquatic ecosystems. A systematic comparison of the accuracy and precision of the most commonly used methods to analyze δ15N in NO3− and NH4+ and interlaboratory comparison tests to evaluate the comparability of isotope results between laboratories are, however, still lacking. Methods Here, we conducted an interlaboratory comparison involving 10 European laboratories to compare different methods and laboratory performance to measure δ15N in NO3− and NH4+. The approaches tested were (a) microdiffusion (MD), (b) chemical conversion (CM), which transforms Ni to either N2O (CM-N2O) or N2 (CM-N2), and (c) the denitrifier (DN) methods. Results The study showed that standards in their single forms were reasonably replicated by the different methods and laboratories, with laboratories applying CM-N2O performing superior for both NO3− and NH4+, followed by DN. Laboratories using MD significantly underestimated the “true” values due to incomplete recovery and also those using CM-N2 showed issues with isotope fractionation. Most methods and laboratories underestimated the at%15N of Ni of labeled standards in their single forms, but relative errors were within maximal 6% deviation from the real value and therefore acceptable. The results showed further that MD is strongly biased by nonspecificity. The results of the environmental samples were generally highly variable, with standard deviations (SD) of up to ± 8.4‰ for NO3− and ± 32.9‰ for NH4+; SDs within laboratories were found to be considerably lower (on average 3.1‰). The variability could not be connected to any single factor but next to errors due to blank contamination, isotope normalization, and fractionation, and also matrix effects and analytical errors have to be considered

Potentiation of thrombus instability: a contributory mechanism to the effectiveness of antithrombotic medications

© The Author(s) 2018The stability of an arterial thrombus, determined by its structure and ability to resist endogenous fibrinolysis, is a major determinant of the extent of infarction that results from coronary or cerebrovascular thrombosis. There is ample evidence from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications have shear-dependent effects, potentiating thrombus fragility and/or enhancing endogenous fibrinolysis. Such shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, likely contribute to the clinical effectiveness of such medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. These effects are observable only with techniques that subject the growing thrombus to arterial flow and shear conditions. The effects of antithrombotic medications on thrombus stability and ways of assessing this are reviewed herein, and it is proposed that thrombus stability could become a new target for pharmacological intervention.Peer reviewedFinal Published versio

Non-immune diabetes mellitus in children due to heterozygous mutations in the glucokinase gene (GCK-MODY): data of 144 patients

BACKGROUND: Monogenic diabetes mellitus (MDM) is a rare form of diabetes mellitus (DM) which caused by one or more mutations in one of the genes that cause pancreatic β-cell dysfunction. Despite the sufficient knowledge of the most common subtypes of MODY, cases of MDM are undiagnosed and classified as type 1 diabetes mellitus and type 2 diabetes mellitus.AIM: To study the clinical, laboratory characteristics, as well as age-related features of GCK-MODY in children.MATERIALS AND METHODS: The studied population is patients with GCK-MODY under the age of 18 years. The diagnosis was confirmed by genetic test, a heterozygous mutation was identificated in the GCK gene.RESULTS: MODY-GCK was verified in 144 patients (131 probands and 13 siblings) under the age of 18 years. Missense mutations were detected in 80.2% (n=105). Mutation was detected in one case in 59.6%. The most common missense mutations were p.G261R (n=7) and p.G258C (n=6). The age of diagnosis of carbohydrate metabolism disorders was 7.6 years [4.0; 11.2]. In 72.2% carbohydrate metabolism disorders were diagnosed accidentally, in 16.7% the examination was provided due to a family history of diabetes, 11.1% had clinical symptoms of diabetes. Fasting glycemia at diagnosis was 6.8 mmol / l [6.4; 7.3], HbA1c — 6.4% [6.1; 6.7]. At examination, the level of fasting glycemia corresponded to normal values in 16.4% of patients, impaired fasting glycemia — in 57.8%, diabetic — in 25.8%. In 62.3% of patients was impaired glucose tolerance, in 18.9% — to diabetic values, and in 11.7% of patients — to a normal level at 120 minutes during the oral glucose tolerance test. A moderate positive correlation was found between the age of examination and the levels of fasting glycemia (r=0.347, p<0.01), C-peptide (r=0.656, p<0.001), and insulin (r=0.531, p<0.001). Insulin resistance (IR) (HOMA index) was detected in 21 patients (14.5%), obesity — in 6 patients (4.2%). In 9 patients (6.25%) was revealed a moderate increase in the titer of specific pancreatic antibodies (AT). The presence of IR, obesity, AT did not affect the level of HbA1c. In 92.3% diet was priscribed, in 4.2% insulin was prescribed, 2.1% — metformin, 1.4% — sulfonylureas.CONCLUSION: In children, disorders of carbohydrate metabolism in GCK-MODY are diagnosed accidentally, asymptomatically at any age from birth, and are characterized by a combination of impaired fasting glycemia and impaired glucose tolerance and, as a rule, do not require antihyperglycemic therap

May Measurement Month 2017: analysis of the blood pressure screening results in Argentina-Americas

Hypertension is a growing concern worldwide, causing over 10 million deaths each year. The prevalence of high blood pressure (BP) in Argentina is 36.3% and 38% of these are unaware of their disease. Half of the hypertensive patients are on pharmacological treatment and only a quarter of them are controlled. The International Society of Hypertension initiated the May Measurement Month (MMM) as a global campaign to raise awareness on high BP that may also serve as a temporary solution to the lack of global screening programs worldwide. A volunteer cross-sectional survey was carried out in May 2017 across 56 health centres. Blood pressure measurement, definition of hypertension and statistical analysis followed the MMM protocol. For this awareness campaign, the Argentine Society of Hypertension coined the slogan: 'Know and control your blood pressure'. A total of 32 346 individuals aged at least 18 years were screened during MMM17. After imputation, 16 263 (50.4%) were hypertensive. Of the 12 156 receiving antihypertensive medication 5400 (44.4%) still had uncontrolled BP. MMM17, called in our country 'Know and control your blood pressure', was the largest BP screening campaign done in Argentina. Almost 6 out of 10 hypertensive patients were either not on treatment or were not controlled to the BP goal. These results suggest that appropriate screening can help to identify a significant number of people with high BP

MODY caused by a mutation in the insulin gene

MODY10 is a rare subtype of MODY diabetes, which caused by heterozygous mutations in the insulin gene INS. There are single descriptions of families with MODY-INS or MODY10 in the literature, its clinical course is not well understood. We present a case of MODY10 in a boy with a history of diabetes mellitus (DM) in three generations (father and paternal grandmother). Proband was diagnosed with diabetes mellitus at the age of 7 years. The glycaemia at the onset of the diabetes was 10.2 mmol/l, HbA1c — 7.6%, islet cell autoantibodies (ICA), insulin autoantibodies (IAA), glutamic acid decarboxylase antibodies (GADA) and islet tyrosine phosphatase 2 (IA2) antibodies (IA2) were not detected. According to the results of the oral glucose tolerance test, fasting blood glucose was 6.5 mmol/l, in 120 minutes 10.3 mmol/l, which corresponded to the diagnosis of impaired glucose tolerance. Diet with restriction of easily digestible carbohydrates was recommended, than gliclazide was added to the therapy, which the proband received for 3 years. At the age of 10, a deterioration in the parameters of carbohydrate metabolism was noted, which insulin therapy was added. Examination at the age of 12 revealed a decrease in C-peptide secretion. The child’s father has a similar phenotype — slowly progressive disorders of carbohydrate metabolism from 6 years old, from 10 years old — insulin therapy. A genetic test was provided, in the child and his father was detected a previously undescribed heterozygous mutation in the INS p.C31W. Thus, in our clinical case, MODY10 was characterized by a milder course than T1DM, but eventually leading to the development of insulin demand, which distinguishes it from the most common forms of MODY. Currently, there is no specific therapy, and the detection of a mutation in the INS gene does not affect therapeutic tactics, however, a correct genetic diagnosis makes it possible to predict the course of diabetes and provide genetic counseling to the family