Spacetime Singularities in String and its Low Dimensional Effective Theory

Spacetime singularities are studied in both the $D+d$-dimensional string theory and its $D$-dimensional effective theory, obtained by the Kaluza-Klein compactification. It is found that spacetime singularities in the low dimensional effective theory may or may not remain after lifted to the $D+d$-dimensional string theory, depending on particular solutions. It is also found that there exist cases in which spacetime singularities appearing in high/low dimensional spacetimes do not necessarily happen on the same surfaces.Comment: revtex4, 15 pages, 10 figures. Typos are corrected. Version to appear in Inter. J. Mod. Phys.

Relationships between Lower-body Power, Sprint and Change of Direction Speed among Collegiate Basketball Players by Sex

International Journal of Exercise Science 15(6): 974-984, 2022. The purpose of this study was to determine if significant relationships exist between absolute and relative lower-body power and selected measures of speed among male and female collegiate basketball players. Archived performance testing data from 29 (male = 14; female = 15) NCAA division II collegiate basketball players were used for this analysis. These measures included lane agility, 10-yard sprint, and shuttle run time (sec). A Pearson’s correlation coefficient was used to determine if significant relationships existed between measures of lower-body power and linear sprint time, change of direction speed (CODS), and shuttle performance. Statistical significance was set a priori at p ≤ 0.05. A significant large correlation was found between absolute power and lane agility (r = 0.54, p = 0.05) among male players. No significant correlations were found between absolute or relative power for 10-yard sprint times, lane agility, or shuttle run performance (p \u3e 0.05). Females showed no significant correlations between relative power and lane agility (r = -0.25, p = 0.37) or 10-yard sprint (r = -0.47, p = 0.08), but did show a significant large correlation (r = -0.64, p = 0.01) between relative power and shuttle run performance. Generating high amounts of relative power is vital in intermittent team sports such as basketball. In particular, this study provided evidence that relative power in female collegiate basketball players is significantly related to shuttle run ability

Levels of Analysis in Comprehensive River Basin Planning

Since nearly every water resource managment choice has two or more sides, differences must be resolved in decision making. Equitable resolution requires an understanding of the reasons for the differences. These reasons originate in the implemented plans have physical-environmental, economic, social, cultural, and political impacts at levels ranging from local to national or international in scope. Decisions are made by individuals and groups impacted in all of these dimensions and at all of these levels; the decisions generate additional impacts; and the entire interactive process changes water management practice in ways outside the control of any one decision point or even dicision dimension. The objective of this study is to conceptualize this process in a way that will help in establishing institutional mechanisms for reconciling differences among levels of analysis. The conceptualization used viewed differences in choices being made at the various levels of analysis as associated with perspective differences having value, jurisdiction, action, and temporal elements. The possible combinations of differences within and between these elements were used to identify ten categories of institutional obstacles to efficient water planning (differences in values, conflicts between value and jurisdiction, etc.). The history of water resources planning on the Colorado River basin was then examined to identify 17 specific institutional obstacles, and a computerized policy simulation was applied to levels of analysis in the Uintah basin of Utah to identify three more. These 20 obstacles were shown to be broadly distributed over the ten categories, and the nature of the obstacles defined provides valuable insight into the common characteristics of the major institutional obstacles to water management. The priciples of logic as applicable to rationality in decision making were then used to identify two root causes of levels\u27 conflicts. If alternatives are evaluated from a single perspective, the ostensible causal relationships commonly used lead to estimates of the sum of the consequences from the parts of a water management program being far more than the total consequences of the entire program. Looked at another way, since available water resources planning tools do not properly allocate consequences from interactive processes to individual causal sources, decisions made to acheive a desired impact are not based on reliable information. In fact, different decisions made over time from a single perspective have conflicting impacts. When multiple perspectices are considered, one finds that individual values do not aggregate linearly in forming social values, many actions are not efficient in achieving preferred values, and decision makers are not able to implement their plans as desired. Real world situations combine interacting perspectives and partial contributions. Nine recommendations are made on what to do next in improving water resources planning in an interactive, nonlinear world

‘Teachers’ to ‘academics’: the implementation of a modernisation project at one UK post-92 university

Among the many external forces that have impacted upon institutions, league tables have been the dynamic to which universities across the world are now responding. Following the appointment of a new vice-chancellor at one post-92 UK university, a modernisation project was introduced aimed at maximising the institutions’ research standing. For the institutional actors, the university’s lecturers, this modernisation project demanded a change in their working practices from one which had focused on teaching related activities to a situation where an emphasis was to be placed upon research. This study examines how university teachers at this institution understood and responded to the modernisation project to acquire research skills and provides an insight into a path-breaking strategic plan that was enacted within an historically dependent setting. It muses on the dialectics of institutional path dependency and the path breaking effect of a modernisation project that was stimulated by new managerialism

Colliding branes and formation of spacetime singularities in string theory

Colliding branes without $Z_{2}$ symmetry and the formation of spacetime singularities in string theory are studied. After developing the general formulas to describe such events, we study a particular class of exact solutions first in the 5-dimensional effective theory, and then lift it to the 10-dimensional spacetime. In general, the 5-dimensional spacetime is singular, due to the mutual focus of the two colliding 3-branes. Non-singular cases also exist, but with the price that both of the colliding branes violate all the three energy conditions, weak, dominant, and strong. After lifted to 10 dimensions, we find that the spacetime remains singular, whenever it is singular in the 5-dimensional effective theory. In the cases where no singularities are formed after the collision, we find that the two 8-branes necessarily violate all the energy conditions.Comment: revtex4, 13 figures. Some typos were corrected, and new refereeces added. Final version to appear in JHE

Historia de un campamento del Horizonte Medio de Huarmey, Perú (PV35-4)

Se presenta el estudio de un campamento temporal del Horizonte Medio situado en el desierto costero peruano al norte del valle de Huarmey. Se ha excavado la parte central del mismo pues presentaba la mayor cantidad de basura y dos fogones. Se ha podido establecer a base de la cerámica encontrada, que el sitio corresponde al Horizonte Medio 3. Los artefactos hallados son muy pocos, lo que es lógico dada la corta ocupación del sitio. Sin embargo se ha podido estudiar los abundantes restos botánicos y animales así como los fecales de llama que estaban acumulados en el lugar. También se ha encontrado coprolitos humanos. De ambos se ha realizado el examen polínico. Además de los excrementos humanos se ha efectuado el análisis del contenido de plantas y animales así como el parasitológico.Cet article étudie un campement temporaire de l’Horizon Moyen situé dans le désert côtier péruvien au nord de la vallée de Huarmey. La partie centrale du site a été choisie pour les fouilles car elle offrait la plus grande quantité de déchets ainsi que deux foyers. Il a été établi que le site correspondait à l’Horizon Moyen 3 grâce à la céramique qui y fut trouvée. Peu d’outillage a été trouvé en raison de la courte occupation du site, mais les restes abondants d’animaux et botaniques ainsi que les restes fécaux de llamas et humains accumulés sur le site ont fourni de précieuses indications. Les résultats des examens polliniques des coprolithes ainsi que les analyses du contenu de plantes, animaux et parasytes présents dans les coprolithes humains sont présentés ici.This is a study of a Middle Horizon temporary campsite located in the peruvian north coastal desert of the Huarmey Valley. The excavation was undertaken in the central part of the site since it contained the largest quantity debris and evidence of two bonfires. Its age was established using pieces of ceramic found on the site. A few artifacts were founded, probably due to the brief occupancy of the site, but were able to study the abundant botanical and animal remains, as well as llama and human coprolites. We present the results of tests for pollen in both the llama and human coprolites, as well as of tests for plant, animal, and parasite content in the human fecal remains are presented here