Algebraic, geometric, and stochastic aspects of genetic operators

Genetic algorithms for function optimization employ genetic operators patterned after those observed in search strategies employed in natural adaptation. Two of these operators, crossover and inversion, are interpreted in terms of their algebraic and geometric properties. Stochastic models of the operators are developed which are employed in Monte Carlo simulations of their behavior

Mycorrhizal colonization of Hypericum perforatum L. (Hypericaceae) on adjacent serpentine and granite outcrops on the Deer Isles, Maine, USA

Given the paucity of literature on plant-fungal interactions on serpentine soils and limited investigation of serpentine geoecology in eastern North America, we examined mycorrhizal colonization of Hypericum perforatum from adjacent serpentine and granite outcrops on the Deer Isles, ME to determine whether plants were differentially colonized based on substrate. We coincided our sampling with three phenologic stages of H. perforatum (preflowering, flowering, postflowering) to determine possible differences in colonization based on plant phenology. The levels of mycorrhizal colonization in H. perforatum were not significantly different between serpentine and granite sites, while levels of colonization in postflowering plants were significantly higher than in those at preflowering and flowering stages

Analysis of milling of dry compacted ribbons by distinct element method

Fine cohesive powders are often dry granulated to improve their flowability. Roller compaction is commonly used to produce dense ribbons which are then milled. The material properties of the powder and the conditions in the roller compactor affect the strength of the ribbons, however there is no method in the literature to predict the size distribution of the product of ribbon milling. Here we introduce a method, by using the Distinct Element Method (DEM) to determine the prevailing impact velocities and stresses in the mill, with bonded spheres representing the ribbons. The bond strength is calibrated by matching experimental results of three point bend measurements and predictions from numerical simulations. The ribbons are then exposed to the dynamic conditions predicted by the DEM, by dropping them from a controlled height to cause fragmentation, and subsequently stressing them in a shear cell under the conditions again predicted by the DEM. The fragments are sheared under these conditions to represent repeated passage of bars over the fragments at the mill base. Sieve analysis is used here to determine the particle size distribution under given mill conditions. The predicted size distribution of the mill product compares well with the plant data. It is found that the mill speed and length of ribbons fed to the mill have no significant influence on the product size distribution for the range tested

The influence of building materials on the residual action of BHC

A atividade residual dos vapores do inseticida BHC de vários materiais de construção em câmaras com controle de umidade, no laboratório, foram significativamente diferentes entre si. Ninfas do primeiro estágio de Dipetalogaster maximus, criados em laboratório, foram expostas a vapores de BHC liberados da superfície tratada dos materiais de construção trazidos de Mambaí, Goiás.Residual insecticide activity of BHC vapors from various building materials in controlled humidity chambers in the laboratory were significantly different. Laboratory-reared, first instar nymphs of Dipetalogaster maximus were exposed to vapors of BHC which were being released from the treated surfaces of building materials taken from Mambaí, Goiás

National and sub-national HIV/AIDS-related mortality in Iran, 1990–2015: a population-based modeling study

Surveillance of HIV/AIDS mortality is crucial to evaluate a country’s response to the disease. With a modified estimation approach, this study aimed to provide more accurate estimates on deaths due to HIV/AIDS in Iran from 1990 to 2015 at national and sub-national levels. Using a comprehensive data set, death registration incompleteness and misclassification were addressed by demographical and statistical methods. Trends of mortality due to HIV/AIDS at national and sub-national levels were estimated by applying a set of models. A total of 474 men (95% uncertainty interval [UI]: 175–1332) and 256 women (95% UI: 36–1871) died due to HIV/AIDS in 2015 in Iran. Peaked in 1995, HIV/AIDS-related mortality has steadily declined among both genders. Mortality rates were remarkably higher among men than women during the period studied. At the sub-national level, the highest and the lowest annual percent change were found at 10.97 and −1.36% for women, and 4.04 and −3.47% for men, respectively. The findings of our study (731 deaths) were remarkably lower than the Joint United Nations Programme on HIV and AIDS (4000) but higher than Global Burden of Disease (339) estimates in 2015. The overall decrease in mortality due to HIV/AIDS may be attributed to the increasing burden of noncommunicable diseases; however, the role of the national and international organizations to fight HIV/AIDS should not be overlooked. To decrease HIV/AIDS mortality and to achieve international goals, evidence-based action is required. To fast-track targets, the priority must be to prevent infection, promote early diagnosis, provide access to treatment, and to ensure treatment adherence among patients. Keywords HIV, AIDS, mortality, estimation, modeling, Ira

PRIVATE SAVINGS IN TRANSITION ECONOMIES: ARE THERE TERMS OF TRADE SHOCKS?

The paper examines the impact of terms of trade shocks on private savings in the transition economies after accounting for the effect of other determinants. Economic agents in the transition economies are subject to tight credit constraints which are more pronounced during bad state of nature. Thus, adverse shocks to commodity prices in the world market can force them to reduce savings by a larger amount than they would otherwise have. Empirical analysis using a dynamic panel model and data from twenty one transition economies confirm that most of the determinants of savings identified in the literature also apply to the transition economies. Favorable movements in both the permanent and transitory components of the terms of trade have a significant positive impact on private savings with transitory movements having a larger impact than the permanent component. This reflects the lack of access to foreign borrowing that many of the transition economies have faced during the last decade. Although the impact of terms of trade shocks are found to be asymmetric, the magnitude of the impact appears to be small. The results are robust for alternative estimators, determinants, and country groupings.http://deepblue.lib.umich.edu/bitstream/2027.42/39958/3/wp572.pd

Exploring concepts of health with male prisoners in three category-C English prisons

Lay understandings of health and illness have a well established track record and a plethora of research now exists which has examined these issues. However, there is a dearth of research which has examined the perspectives of those who are imprisoned. This paper attempts to address this research gap. The paper is timely given that calls have been made to examine lay perspectives in different geographical locations and a need to re-examine health promotion approaches in prison settings. Qualitative data from thirty-six male sentenced prisoners from three prisons in England were collected. The data was analysed in accordance with Attride-Stirling's (2001) thematic network approach. Although the men's perceptions of health were broadly similar to the general population, some interesting findings emerged which were directly related to prison life and its associated structures. These included access to the outdoors and time out of their prison cell, as well as maintaining relationships with family members through visits. The paper proposes that prisoners' lay views should be given higher priority given that prison health has traditionally been associated with medical treatment and the bio-medical paradigm more generally. It also suggests that in order to fulfil the World Health Organization's (WHO) vision of viewing prisons as health promoting settings, lay views should be recognised to shape future health promotion policy and practice

From prison to detention: the carceral trajectories of foreign-national prisoners in the United Kingdom

The United Kingdom has taken an increasingly punitive stance towards ‘foreign criminals’ using law and policy to pave the way for their expulsion from the country. Imprisonment, then, becomes the first stage in a complex process intertwining identity, belonging and punishment. We draw here on research data from two projects to understand the carceral trajectories of foreign-national offenders in the UK. We consider the lived experiences of male foreign-nationals in two sites: prison and immigration detention. The narratives presented show how imprisonment and detention coalesce within the deportation regime as a ‘double punishment’, one that is highly racialised and gendered. We argue that the UK’s increasingly punitive response to foreign-national offenders challenges the traditional purposes of punishment by sidestepping prisoners’ rehabilitative efforts and denying ‘second chances’ while enacting permanent exclusion through bans on re-entry