On the density of abelian surfaces with Tate- Shafarevich group of order five times a square

Let A=E_1xE_2 be be the product of two elliptic curves over QQ, both having a rational five torsion point P_i. Set B=A/. In this paper we give an algorithm to decide whether the Tate-Shafarevich group of the abelian surface B has square order or order five times a square, assuming that we can find a basis for the Mordell-Weil groups of both E_i, and that the Tate-Shafarevich groups of the E_i are finite. We considered all pairs (E_1,E_2), with prescribed bounds on the conductor and the coefficients on a minimal Weierstrass equation. In total we considered around 20.0 million of abelian surfaces of which 49.16% have a Tate-Shafarevich group of non-square order.Comment: 17 pages, 10 table

Intra-household effects of ENSO related drought in lowland farm households in Central Sulawesi, Indonesia

137 p. Georg-August-University of Göttingen, GermanyThe principal aim of the present study is to define the intra-household impact of El Niño 2002 on time and food allocation. Moreover, to determine how the roles of men and women were affected. This study focused at the intra – household level, since the effect of El Niño 2002 on the household was previously determined by Keil (2004). Thereby, the study contributes to achieve a more detail understanding of El Niño impact in the year 2002. The realization of the study was within the focus of the IMPENSO project (Impact of El Niño-Southern Oscillation). The study is composed of two parts. The first part refers to the quantitative study, and the second part to the qualitative study. As Keil (2004) concluded, the highest impact of El Niño 2002 was localized in three lowland villages in Central Sulawesi, Indonesia. Therefore, the quantitative study was based on a random sample of 96 household, used by Keil (2004). Meanwhile, the qualitative study was based on 3 different research methods. The number of respondents of each one corresponds to: 18 in-depth interviews, 3 focus groups and 9 key informants’ semi-structure interviews. Therefore, by applying qualitative and quantitative methods it was approached the same phenomenon from different analysis. Thus, the results and explanations obtained from the analyses, led us to stronger conclusions than if it would be applied a single method.In order to analyse the data, the study was sub-divided in two parts. Firstly, the quantitative analysis consists of the time allocation analysis and the food allocation analysis. Secondly, the qualitative analysis was divided into in-depth interviews analysis, focus groups analysis and key informants’ analysis. Both parts derive and conclude about the same issues. These issues are the differentiated effect of El Niño 2002 on men and women, on the age of the household members and on the wealth strata of the household members. In order to identify the possible impact of El Niño in the year 2002, it was compared to the non-El Niño year nearest to the year when the present research was done. The activities and food selected were based on the results from Keil (2004). Thereby, the analyses are concentrated on the most affected activities. These activities were the rice production, temporary employment, maize production, cocoa production and other activities. These ‘other activities’ comprised several activities, which were not as important as the above mentioned, regarding the amount of time allocated and the quantity of household members engaged. However, these did have importance due to they represent the diversity of activities in the research area. Furthermore, they represent the differentiated effect of El Niño 2002 on time allocation.The food allocation analysis consists of the change on consumption of rice, maize, rice mixed with rice, cassava, vegetables, banana, fish, chicken and beef. The effect of El Niño 2002 on food allocation depended on the kind of food. Therefore, there were foods consumed in more quantity during El Niño 2002 than 2004, such as rice mixed with maize and cassava. On the other hand, other foods were consumed in less quantity during El Niño 2002 than 2004, such as fish and rice. Furthermore, the qualitative research found that women were in charge of allocating the food within the household. Therefore, the wife gave priority on food allocation to other members to consume the staple foods like rice. For instance, in some situations during El Niño 2002, the wife reduced the amount consumed of some foods like rice, chicken or beef. On its place she increased the amount of other foods like banana (instead of rice), more quantity of vegetables. Thereby, that fact caused during El Niño 2002 a detrimental food allocation towards women.The time allocation impact of El Niño 2002 depended on the kind of activity. Therefore, in temporary employment, maize production, construction worker, fishing and the collection of rattan more hours have been worked during El Niño 2002 than in 2004. On the other hand, crops as rice, banana and chilli production perceived a reduction of hours worked during El Niño 2002. Furthermore, El Niño 2002 reduced the time that women were outside the house. Additionally, a minimum change in men’s participation in the daily tasks has been observed. On the other hand, men’s principal obligation sometimes implied the mobilization to other places, a fact that was accepted in the society; meanwhile women had less spatial mobility. Moreover, new and more diverse activities were fulfilled during El Niño 2002. Furthermore, the effect of El Niño 2002 pushed for the incremental participation of women in self-employment outside the agriculture. Therefore future local decisions should take into account the new alternatives activities developed since El Niño 2002. In which the participation of women has been incremented. Moreover, there were differences between villages regarding the effect of El Niño 2002 on the intra-household allocation of time and food. The analysed effects of El Niño 2002 on time and food allocation among the household members are strongly recommended to be included in future decisions in development projects within the research area. This has the aim to focus the attention on the household members that were most affected, especially on the activities and foods that the present study addresses. Furthermore, special attention must be given to women, the poorest and poor household member

Geometric potential and transport in photonic topological crystals

We report on the experimental realization of an optical analogue of a quantum geometric potential for light wave packets constrained on thin dielectric guiding layers fabricated in silica by the femtosecond laser writing technology. We further demonstrate the optical version of a topological crystal, with the observation of Bloch oscillations and Zener tunneling of purely geometric nature

State-level trends in sudden unexpected infant death and immunization in the United States: an ecological study

Background: Sudden unexpected infant death (SUID) continues to be a major contributor to infant mortality in the United States. The objective was to analyze time trends in SUID and their association with immunization coverage. Methods: The number of deaths and live births per year and per state (1992-2015) was obtained from the Centers for Disease Control and Prevention (CDC). We calculated infant mortality rates (i.e., deaths below one year of age) per 1000 live births for SUID. We obtained data on immunization in children aged 19-35 months with three doses or more of diphtheria-tetanus-pertussis (3+ DTP), polio (3+ Polio), and Haemophilus influenzae type b (3+ Hib) as well as four doses or more of DTP (4+ DTP) from the National Immunization Survey, and data on infant sleep position from the Pregnancy Risk Assessment Monitoring System (PRAMS) Study. Data on poverty and race were derived from the Current Population and American Community Surveys of the U.S. Census Bureau. We calculated mean SUID mortality rates with 95% confidence interval (CI) as well as the annual percentage change using breakpoint analysis. We used Poisson regression with random effects to examine the dependence of SUID rates on immunization coverage, adjusting for sleep position and poverty (1996-2015). In a second model, we additionally adjusted for race (2000-2015). Results: Overall, SUID mortality decreased in the United States. The mean annual percent change was - 9.6 (95% CI = - 10.5, - 8.6) between 1992 and 1996, and - 0.3 (95% CI = - 0.4, - 0.1) from 1996 onwards. The adjusted rate ratios for SUID mortality were 0.91 (95% CI = 0.80, 1.03) per 10% increase for 3+ DTP, 0.88 (95% CI = 0.83, 0.95) for 4+ DTP, 1.00 (95% CI = 0.90, 1.10) for 3+ polio, and 0.95 (95% CI = 0.89, 1.02) for 3+ Hib. After additionally adjusting for race, the rate ratios were 0.76 (95% CI = 0.67, 0.85) for 3+ DTP, 0.83 (95% CI = 0.78, 0.89) for 4+ DTP, 0.81 (95% CI = 0.73, 0.90) for 3+ polio, and 0.94 (95% CI = 0.88, 1.00) for 3+ Hib. Conclusions: SUID mortality is decreasing, and inversely related to immunization coverage. However, since 1996, the decline has slowed down

Quantum walks of correlated photon pairs in two-dimensional waveguide arrays

We demonstrate quantum walks of correlated photons in a 2D network of directly laser written waveguides coupled in a 'swiss cross' arrangement. The correlated detection events show high-visibility quantum interference and unique composite behaviour: strong correlation and independence of the quantum walkers, between and within the planes of the cross. Violations of a classically defined inequality, for photons injected in the same plane and in orthogonal planes, reveal non-classical behaviour in a non-planar structure.Comment: 5 pages, 5 figure

The random mass Dirac model and long-range correlations on an integrated optical platform

Long-range correlation-the non-local interdependence of distant events-is a crucial feature in many natural and artificial environments. In the context of solid state physics, impurity spins in doped spin chains and ladders with antiferromagnetic interaction are a prominent manifestation of this phenomenon, which is the physical origin of the unusual magnetic and thermodynamic properties of these materials. It turns out that such systems are described by a one-dimensional Dirac equation for a relativistic fermion with random mass. Here we present an optical configuration, which implements this one-dimensional random mass Dirac equation on a chip. On this platform, we provide a miniaturized optical test-bed for the physics of Dirac fermions with variable mass, as well as of antiferromagnetic spin systems. Moreover, our data suggest the occurence of long-range correlations in an integrated optical device, despite the exclusively short-ranged interactions between the constituting channels

International time trends in sudden unexpected infant death, 1969–2012

Background: Sudden unexpected infant death (SUID) - including sudden infant death syndrome (SIDS) - continues to be a major contributor to infant mortality worldwide. Our objective was to analyse time trends and to identify country-clusters. Methods: The National Statistical Offices of 52 countries provided the number of deaths and live births (1969-2012). We calculated infant mortality rates per 1000 live births for SUID, SIDS, and all-cause mortality. Overall, 29 countries provided sufficient data for time course analyses of SUID. To sensitively model change over time, we smoothed the curves of mortality rates (1980-2010). We performed a hierarchical cluster analysis to identify clusters of time trends for SUID and SIDS, including all-cause infant mortality. Results: All-cause infant mortality declined from 28.5 to 4.8 per 1000 live births (mean 12.4; 95% confidence interval 12.0-12.9) between 1969 and 2012. The cluster analysis revealed four country-clusters. Clusters 1 and 2 mostly contained countries showing the typical peak of SUID mortality during the 1980s. Cluster 1 had higher SUID mortality compared to cluster 2. All-cause infant mortality was low in both clusters but higher in cluster 1 compared to cluster 2. Clusters 3 and 4 had low rates of SUID without a peak during the 1980s. Cluster 3 had the highest all-cause infant mortality of all clusters. Cluster 4 had an intermediate all-cause infant mortality. The time trends of SUID and SIDS mortality were similar. Conclusions: The country-specific time trends in SUID varied considerably. The identification of country-clusters may promote research into how changes in sleep position, smoking, immunisation, or other factors are related to our findings