Spectral Theory of Time Dispersive and Dissipative Systems

We study linear time dispersive and dissipative systems. Very often such systems are not conservative and the standard spectral theory can not be applied. We develop a mathematically consistent framework allowing (i) to constructively determine if a given time dispersive system can be extended to a conservative one; (ii) to construct that very conservative system -- which we show is essentially unique. We illustrate the method by applying it to the spectral analysis of time dispersive dielectrics and the damped oscillator with retarded friction. In particular, we obtain a conservative extension of the Maxwell equations which is equivalent to the original Maxwell equations for a dispersive and lossy dielectric medium.Comment: LaTeX, 57 Pages, incorporated revisions corresponding with published versio

Entanglement-free Heisenberg-limited phase estimation

Measurement underpins all quantitative science. A key example is the measurement of optical phase, used in length metrology and many other applications. Advances in precision measurement have consistently led to important scientific discoveries. At the fundamental level, measurement precision is limited by the number N of quantum resources (such as photons) that are used. Standard measurement schemes, using each resource independently, lead to a phase uncertainty that scales as 1/sqrt(N) - known as the standard quantum limit. However, it has long been conjectured that it should be possible to achieve a precision limited only by the Heisenberg uncertainty principle, dramatically improving the scaling to 1/N. It is commonly thought that achieving this improvement requires the use of exotic quantum entangled states, such as the NOON state. These states are extremely difficult to generate. Measurement schemes with counted photons or ions have been performed with N <= 6, but few have surpassed the standard quantum limit and none have shown Heisenberg-limited scaling. Here we demonstrate experimentally a Heisenberg-limited phase estimation procedure. We replace entangled input states with multiple applications of the phase shift on unentangled single-photon states. We generalize Kitaev's phase estimation algorithm using adaptive measurement theory to achieve a standard deviation scaling at the Heisenberg limit. For the largest number of resources used (N = 378), we estimate an unknown phase with a variance more than 10 dB below the standard quantum limit; achieving this variance would require more than 4,000 resources using standard interferometry. Our results represent a drastic reduction in the complexity of achieving quantum-enhanced measurement precision.Comment: Published in Nature. This is the final versio

Risk perception of arsenic exposure from rice intake in a UK population

In the UK, consumption of rice and rice-based products is on the rise but, notwithstanding public expressed concerns about such products as an exposure route for arsenic (e.g. BBC News report, 2017“Should I worry about arsenic in my rice?”) there are few, if any published data on public perceptions of risks associated with exposure to arsenic in rice. We therefore aimed to determine the risk perception of arsenic exposure from rice intake and factors that are associated with arsenic knowledge and whether or not this knowledge had an influence on rice consumption and cooking practices. A questionnaire, targeting participation of rice-eating ethnic minorities in Greater Manchester, UK, was administered to 184 participants. A multivariate generalized linear model was used to determine the factors associated with rice consumption behaviour, cooking practices, and risk perception. We show for the first time that the general population did not associate arsenic, which they perceive as toxic to health, with rice consumption. More than half of the participants knew about arsenic as a hazardous substance but less than ten percent knew that rice consumption could be an important route of arsenic exposure. Knowledge of arsenic was significantly lower in Asian/Asian British:Pakistanis (Pakistani) (OR: 0.006; 95% CI:0.00-0.03) and Asian/Asian British:Bangladeshis (Bangladeshi) (OR: 0.064; 95% CI:0.01-0.25) compared to White:English/Welsh/Scottish/Northern Irish/British (White British). Moreover, Bangladeshis consumed three times more rice (OR: 2.92; 95% CI:1.73-4.93) compared to White British. Overall higher rice consumption was not associated with higher knowledge of the nutritional value of rice. Rinsing rice before cooking, an effective arsenic removal technique, was practised by 93% of the participants, however the most popular cooking method was the use of adequate water (rice to water ratio of 1:2) but not excess water (rice to water ratio of > 1:4), the latter being more effective in removing arsenic. Better education, higher weekly expenditure on food and prior knowledge of arsenic hazard were all significant factors positively influencing a change in behaviour to reduce arsenic exposure from rice intake

Natural language processing

Beginning with the basic issues of NLP, this chapter aims to chart the major research activities in this area since the last ARIST Chapter in 1996 (Haas, 1996), including: (i) natural language text processing systems - text summarization, information extraction, information retrieval, etc., including domain-specific applications; (ii) natural language interfaces; (iii) NLP in the context of www and digital libraries ; and (iv) evaluation of NLP systems

A Placebo-Controlled Trial of Pioglitazone in Subjects with Nonalcoholic Steatohepatitis

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Attitudes to and management of fertility among primary health care physicians in Turkey: An epidemiological study

BACKGROUND: The subject of infertility has taken its place in the health sector at the top level. Since primary health care services are insufficient, most people, especially women, keep on suffering from it all over the world, namely in underdeveloped or developing countries. The aim of this study was to determine primary care physicians' opinions about the approach to infertility cases and their place within primary health care services (PHCSs). METHODS: The study was conducted between October 2003 and April 2004. The study group comprised 748 physicians working in PHCSs. They were asked to fill in a questionnaire with questions pertaining to infertility support, laboratory and treatment algorithms, as well as the demographic characteristics. The data was evaluated using the chi square test, percentage rates and a logistic regression model. RESULTS: The multivariate analyses showed that having a previous interest in infertility and having worked for a postgraduate period of between 5–9 years and ≥10 years were the variables that most positively influenced them in their approach to cases of infertility (p < 0.05, each one). Just 28.7% of the physicians indicated that they believed cases of infertility could be evaluated at the primary care level. The most frequently proposed reason for indicating 'difficulty in practice' (n = 533) was inadequate provision of equipment in PHCSs (55.7%). The physicians reported that they were able to perform most of the supportive treatments and proposals (between 64.6%–87.7%). The most requested laboratory investigations were the instruction of patients in taking basal body temperatures and semen analysis (89.7% and 88.7%, respectively). The most preferential course of treatment was that of sexually transmitted diseases (95.5%). CONCLUSION: It is clear that not enough importance is attached to the provision of care to infertile couples within PHCSs. This leads us to conclude that an integration of infertility services in primary care would be appropriate after strengthening the PHCSs

Lack of Association of Type 2 Diabetes Susceptibility Genotypes and Body Weight on the Development of Islet Autoimmunity and Type 1 Diabetes

AIM: To investigate whether type 2 diabetes susceptibility genes and body weight influence the development of islet autoantibodies and the rate of progression to type 1 diabetes. METHODS: Genotyping for single nucleotide polymorphisms (SNP) of the type 2 diabetes susceptibility genes CDKAL1, CDKN2A/2B, FTO, HHEX-IDE, HMGA2, IGF2BP2, KCNJ11, KCNQ1, MTNR1B, PPARG, SLC30A8 and TCF7L2 was obtained in 1350 children from parents with type 1 diabetes participating in the BABYDIAB study. Children were prospectively followed from birth for islet autoantibodies and type 1 diabetes. Data on weight and height were obtained at 9 months, 2, 5, 8, 11, and 14 years of age. RESULTS: None of type 2 diabetes risk alleles at the CDKAL1, CDKN2A/2B, FTO, HHEX-IDE, HMGA2, IGF2BP2, KCNJ11, KCNQ1, MTNR1B, PPARG and SLC30A8 loci were associated with the development of islet autoantibodies or diabetes. The type 2 diabetes susceptible genotype of TCF7L2 was associated with a lower risk of islet autoantibodies (7% vs. 12% by age of 10 years, P = 0.015, P(corrected) = 0.18). Overweight children at seroconversion did not progress to diabetes faster than non-overweight children (HR: 1.08; 95% CI: 0.48-2.45, P>0.05). CONCLUSIONS: These findings do not support an association of type 2 diabetes risk factors with islet autoimmunity or acceleration of diabetes in children with a family history of type 1 diabetes

Molecular basis of structure and function of the microvillus membrane of intestinal epithelial cells

Correlation of molecular structure with biochemical functions of the plasma membrane of the microvilli of intestinal epithelial cells has been investigated by biochemical and electron microscopic procedures. Repeating particles, measuring approximately 60 &#197;in diameter, were found on the surface of the microvilli membrane which had been isolated or purified from rabbit intestinal epithelial cells and negatively stained with phosphotungstic acid. These particles were proved to be inherent components of the microvillus membrane, attached to the outer surface of its trilaminar structure, and were designated as the elementary particles of the microvilli of intestinal epithelial cells. Biochemical and electron microscopic identification of these elementary particles has been carried out by isolation of the elementary particles with papain from the isolated microvillus membrane, followed by purification of the particles by chromatographies on DEAE-cellulose and Sephadex columns. The partially purified particles containing invertase and leucine aminopeptidase are similar in size and structure to those of the elementary particles in the microvillus membrane. Evidence indicates that each of the elementary particles coincide with or include an enzyme molecule such as disaccharidase or peptidase, which carry out the terminal hydrolytic digestion of carbohydrates and proteins, respectively, on the surface of the microvillus membrane. Magnesium ionactivated adenosine triphosphatase and alkaline phosphatase cannot be solubilized with papain but remains in the smooth-surface membrane after the elementary particles have been removed. Cytochemical electron microscopic observation revealed that the active site of magnesium ion-activated adenosine triphosphatase is localized predominantly in the inner surface of the trilaminar structure of the microvillus membrane.</p

Family ties of crack cocaine users cared for in a psychiatric emergency department

This study characterizes the family ties of crack cocaine users cared for in a psychiatric emergency department in southern Brazil. It is a qualitative study with a series of cases carried out in the city of Maringá, PR, Brazil from April to June 2010. Data were collected through semi-structured interviews, analyzed using content analysis, and organized into two categories: family ties as facilitators in the use of crack cocaine and other drugs; and fragmented family ties of crack users. Loss of relational bonds with family and social milieu was observed among the ten studied users in addition to the presence of drugs and violence in the family sphere. Further studies addressing the use of crack and its interface with the family are encouraged, taking into consideration that families have an essential role in the initiation and continuity of drug use.El objetivo del estudio fue conocer el vínculo familiar de usuarios de crack atendidos en una Unidad de Emergencia Psiquiátrica del Sur de Brasil. Se trata de una investigación cualitativa, con delineamiento de serie de casos, realizada en el municipio de Maringá, en Paraná, en el período de abril a junio de 2010. Para la recolección de datos se utilizó un guión semiestructurado de entrevista. Los datos fueron analizados siguiendo la técnica de análisis de contenido y organizados en dos categorías: el vínculo familiar como facilitador del uso de crack y otras drogas, y el vínculo familiar fragmentado de los usuarios de crack. Entre los diez usuarios investigados, se evidenció: pérdida de los vínculos relacionales con la familia y con el medio social y, presencia de drogas y violencia en el ambiente familiar. La realización de investigaciones sobre el uso de crack y su interfaz con la familia deben ser estimuladas, ya que las familias poseen un papel fundamental en la iniciación y continuidad del uso de drogas.O objetivo deste estudo foi conhecer o vínculo familiar de usuários de crack, atendidos em uma unidade de emergência psiquiátrica do Sul do Brasil. Trata-se de pesquisa qualitativa, com delineamento de série de casos, realizada no município de Maringá, PR, no período de abril a junho de 2010. Para a coleta dos dados utilizou-se roteiro semiestruturado de entrevista. Os dados foram analisados seguindo a técnica de análise de conteúdo e organizados em duas categorias: o vínculo familiar como facilitador do uso de crack e outras drogas, e o vínculo familiar fragmentado de usuários de crack. Entre os dez usuários investigados, evidenciou-se a perda dos vínculos relacionais com a família e o meio social, presença de drogas e violência no ambiente familiar. A realização de pesquisas sobre o uso de crack e sua interface com a família deve ser estimulada, visto que as famílias possuem papel fundamental na iniciação e continuidade ao uso de drogas