87 research outputs found
Molar mass estimate of dark matter from the dark mass distribution measurements
We study the distribution of dark matter versus visible matter using a set of
data obtained from strong gravitational lensing in the galaxy cluster
CL0024+1654 and another set of data inferred from the universal rotation curves
in spiral galaxies. The important feature of these two dramatically different
observations is that the mass density profile of both visible and dark
components can be estimated. From these measurements we deduce the mass of the
dark matter particle and our estimate of the mass for the dark matter particle
is MeV. We contrast our estimates from CL0024+1654
data and the universal rotation curves of the spiral galaxies and discuss their
consistency.Comment: 14 pages, 13 figure
Beyond spheres of influence: the myth of the state and Russia’s seductive power in Kyrgyzstan
This article questions the analytical value of “spheres of influence” for understanding power and the state in the post-Soviet region and beyond, based on a critical deconstruction of the ontological and epistemological assumptions inherent in the concept. It proposes an alternative reading of power and the state, drawing on the concept of “seductive power” at a distance and Timothy Mitchell’s “state effect.” Rather than the concept of a sphere of influence, a highly politicized concept that conveys an ontology that flattens and divides space, essentializes the state, and relies on an intentionalist account of power, we need an analytical framework that can help us make sense of the multiple, varied spatialities and historical legacies that produce the state and power. I demonstrate this through an extended discussion of Russian power in Kyrgyzstan, a country often described as a Russian client state. Mobilizing recent re-conceptualizations of state and power in anthropology and political geography, I present an analysis of Russia’s seductive power in Kyrgyzstan and the way it contributes to producing Kyrgyz state-ness. I also show how Russia’s Great Power myth is itself evolving and conclude that the differentiated, relational production of space and power in either Kyrgyz or Russian myths of the state is not captured by a the concept of a return to spheres of influence
Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities
BACKGROUND: Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. METHODOLOGY/PRINCIPAL FINDINGS: Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. CONCLUSIONS/SIGNIFICANCE: Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable
Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns
This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa
Vertical segregation of two species of Hyphessobrycon(Characiformes: Characidae) in the Cabiúnas coastal lagoon, southeastern Brazil
Feeding ecology of two sympatric species of large-sized groupers (Perciformes: Epinephelidae) on Southwestern Atlantic coralline reefs
Opinion, knowledge and attitude of public health residents towards the new mandatory vaccination law in Italy
Aim: Due to the introduction of the compulsory vaccination law in Italy, and the following intense debate, the aim of this study was to assess the opinion of Italian Public Health residents and their knowledge on this issue. Subjects and methods: Data were collected using a previously developed and validated online questionnaire that was sent by email to Public Health Residents attending the 35 Post-Graduate Schools of Hygiene and Preventive Medicine in Italy. Multivariate stepwise logistic regression was performed for data analysis, and a 0.05 level of significance was chosen. Results are expressed as adjusted odds ratio (aOR) with 95% confidence intervals (CI). Results: Out of 554 medical doctors, 359 filled in the questionnaire, of which 56.8% were female. Those who had a positive opinion about the Law also strongly agreed/agreed with the following statements: caregivers who do not comply with the mandatory vaccination law should be fined; the Law is the only way to prevent, contain and reduce public health risks; documentation of legally mandated vaccines should be required for children to attend preschools; mandatory vaccinations are necessary and the Decree Law should not be modified; the Law emphasises the importance of all the vaccinations provided by the National Immunisation Plan. Conclusion: Italian Public Health residents agree with compulsory vaccination, considering it a useful and effective tool aimed at increasing the vaccination coverage rate
Efecto del ZnO, ZrO<sub>2</sub> y B<sub>2</sub>O<sub>3</sub> en el proceso de clinkerización. Parte I. Reacciones de clinkerizacion y composición de los clínkeres
- …