The minimum mass of a spherically symmetric object in DD-dimensions, and its implications for the mass hierarchy problem

The existence of both a minimum mass and a minimum density in nature, in the presence of a positive cosmological constant, is one of the most intriguing results in classical general relativity. These results follow rigorously from the Buchdahl inequalities in four dimensional de Sitter space. In this work, we obtain the generalized Buchdahl inequalities in arbitrary space-time dimensions with $\Lambda \neq 0$ and consider both the de Sitter and anti-de Sitter cases. The dependence on $D$, the number of space-time dimensions, of the minimum and maximum masses for stable spherical objects is explicitly obtained. The analysis is then extended to the case of dark energy satisfying an arbitrary linear barotropic equation of state. The Jeans instability of barotropic dark energy is also investigated, for arbitrary $D$, in the framework of a simple Newtonian model with and without viscous dissipation, and we determine the dispersion relation describing the dark energy$-$matter condensation process, along with estimates of the corresponding Jeans mass (and radius). Finally, the quantum mechanical implications of mass limits are investigated, and we show that the existence of a minimum mass scale naturally leads to a model in which dark energy is composed of a `sea' of quantum particles, each with an effective mass proportional to $\Lambda^{1/4}$.Comment: 16 pages, one figure; Section IV extended; references added; accepted for publication in EPJ

THE MODEL OF INTERNAL SUPERVISION OF THE DISTANCE EDUCATION VIA SATELLITE (DLTV) TO ENHANCE THAI LANGUAGE ACHIEVEMENTS OF HUI SI SIAD SCHOOL STUDENTS UNDER LOEI PRIMARY EDUCATION SERVICE AREA OFFICE 2, THAILAND

This study was designed 1) to develop the internal supervision of the distance education via satellite (DLTV) affecting to students’ academic achievement in Thai subject 2) to study the satisfaction of the teachers toward the internal supervision model.3) to study of factors effecting to the success of the distance education via satellite learning. The methodology of the study consisted of 4 steps: 1) setting up the conceptual framework on the internal supervision; 2) analysing the documents concerning facing education problems and the need of internal supervision model;3) constructing the internal supervision; 4) evaluating the model of internal supervision. The instruments were included questionnaire, group discussion and behaviour observing form. The target group consisted of teachers and students of Hui Si Siad school. The data was analysed by using descriptive statistics such as frequency, percentage, mean, standard deviation and content analysis.  The results of the study were as follows:             1)  students’ academic achievement in Thai language subject had passed the 80 percentage of criteria.             2)  the satisfaction of the teachers toward the internal supervision model at a high level.             3) factors effecting the success of the distance education via satellite (DLTV) learning consisted of 3 main factors: 1) the 4 general factors: good environment, TV was properly installed, teachers appraised and gave an willing, students had participation 2) 5 factors that the director should manage: intention leader, manage as a system,  learning equipment were complete, visit learning and teaching process continuously, good at supervising absolutely; 3) factors for teachers to proceed: making a pleasant classroom,  teacher was in the classroom ,preparing teaching in advance, summarizing content, teaching for weak student’s groups and add more teaching techniques

The Adiabatic Transport of Bose-Einstein Condensates in a Double-Well Trap: Case a Small Nonlinearity

A complete adiabatic transport of Bose-Einstein condensate in a double-well trap is investigated within the Landau-Zener (LZ) and Gaussian Landau-Zener (GLZ) schemes for the case of a small nonlinearity, when the atomic interaction is weaker than the coupling. The schemes use the constant (LZ) and time-dependent Gaussian (GLZ) couplings. The mean field calculations show that LZ and GLZ suggest essentially different transport dynamics. Significant deviations from the case of a strong coupling are discussed.Comment: 6 pages, 3 figures, to be published in Laser Physic

A Surprising Similarity Between Holographic CFTs and a Free Fermion in (2+1)(2+1) Dimensions

We compare the behavior of the vacuum free energy (i.e. the Casimir energy) of various $(2+1)$-dimensional CFTs on an ultrastatic spacetime as a function of the spatial geometry. The CFTs we consider are a free Dirac fermion, the conformally-coupled scalar, and a holographic CFT, and we take the spatial geometry to be an axisymmetric deformation of the round sphere. The free energies of the fermion and of the scalar are computed numerically using heat kernel methods; the free energy of the holographic CFT is computed numerically from a static, asymptotically AdS dual geometry using a novel approach we introduce here. We find that the free energy of the two free theories is qualitatively similar as a function of the sphere deformation, but we also find that the holographic CFT has a remarkable and mysterious quantitative similarity to the free fermion; this agreement is especially surprising given that the holographic CFT is strongly-coupled. Over the wide ranges of deformations for which we are able to perform the computations accurately, the scalar and fermion differ by up to 50% whereas the holographic CFT differs from the fermion by less than one percent.Comment: 16+8 pages, 13 figures. v2: References added, minor edit

Gestão organizacional em empresas familiares no Vale do Rio dos Sinos

In the context of business changes, family businesses have often been observed and studied because of their potential for development. Furthermore, these are organizations that have contributed much, and will continue to contribute, to development of the region and the communities, while occupying a prominent position in the business scenario. The organizational practices of management by these businesses in the region of the Vale do Rio dos Sinos were identified and described to provide considerations and potential actions for improving the organizational models adopted. The methodology of exploratory and field research was applied to develop this study. For analysis, the qualitative approach was used to interpret data collected. Results suggest that the family businesses studied implement changes and improvements in their management practices so that organizational models adopted are flexible and adjusted to the globalized world today thereby contributing to growth of the business and also to local, regional and national development as well.En el contexto de las mudanzas empresariales, las empresas familiares han sido objeto frecuente de observación y estudio en consecuencia del potencial de desarrollo que poseen, además del hecho de que esas organizaciones han contribuido y todavía contribuyen para el desarrollo regional y de las comunidades, ocupando una posición de destaque en el escenario de los negocios. Este trabajo tiene como objetivo identificar y caracterizar prácticas organizacionales de gestión en empresas familiares en la región del Vale do Rio dos Sinos, en el sentido de propiciar reflexiones y posibles acciones que visen el perfeccionamiento de los modelos organizacionales adoptados. Para desarrollar este estudio se aplicó la metodología de investigación exploratoria y de campo. El análisis se realizó mediante el abordaje cualitativo, para la interpretación de los datos averiguados en la investigación. Los resultados sugieren que las empresas familiares investigadas pongan en práctica mudanzas y perfeccionamientos en sus prácticas de gestión, para que modelos organizacionales adoptados sean flexibles y ajustados a la realidad del mundo globalizado, contribuyendo de esta forma con el propio crecimiento de la empresa y también con el desarrollo local, regional y nacional.No contexto das mudanças empresariais, as empresas familiares têm sido objeto frequente de observação e estudo em razão do potencial de desenvolvimento que possuem, além do fato de essas organizações terem contribuído muito e ainda contribuírem para o desenvolvimento regional e das comunidades, ocupando uma posição de destaque no cenário dos negócios. Este trabalho tem como objetivo identificar e caracterizar práticas organizacionais de gestão em empresas familiares na região do Vale do Rio dos Sinos, a fim de propiciar reflexões e possíveis ações que visem o aprimoramento dos modelos organizacionais adotados. Aplicou-se a metodologia da pesquisa exploratória e de campo para desenvolver este estudo. A análise deu-se por meio da abordagem qualitativa, para interpretação dos dados apurados na pesquisa. Os resultados do estudo sugerem que as empresas familiares pesquisadas implementem mudanças e aprimoramentos em suas práticas de gestão, para que modelos organizacionais adotados sejam flexíveis e ajustados à realidade do mundo globalizado, contribuindo assim com o próprio crescimento da empresa e também com o desenvolvimento local, regional e nacional

Resolving the homology-function relationship through comparative genomics of membrane-trafficking machinery and parasite cell biology

With advances in DNA sequencing technology, it is increasingly common and tractable to informatically look for genes of interest in the genomic databases of parasitic organisms and infer cellular states. Assignment of a putative gene function based on homology to functionally characterized genes in other organisms, though powerful, relies on the implicit assumption of functional homology, i.e. that orthology indicates conserved function. Eukaryotes reveal a dazzling array of cellular features and structural organization, suggesting a concomitant diversity in their underlying molecular machinery. Significantly, examples of novel functions for pre-existing or new paralogues are not uncommon. Do these examples undermine the basic assumption of functional homology, especially in parasitic protists, which are often highly derived? Here we examine the extent to which functional homology exists between organisms spanning the eukaryotic lineage. By comparing membrane trafficking proteins between parasitic protists and traditional model organisms, where direct functional evidence is available, we find that function is indeed largely conserved between orthologues, albeit with significant adaptation arising from the unique biological features within each lineage

Neuroprotective effects of a medium chain fatty acid, decanoic acid, isolated from H. leucospilota against Parkinsonism in C. elegans PD model

Sea cucumbers are marine organism that have long been used for food and traditional medicine in Asian countries. Recently, we have shown that ethyl acetate fraction (HLEA) of the crude extract of the black sea cucumber, Holothuria leucospilota, could alleviate Parkinsonism in Caenorhabditis elegans PD models. In this study, we found that the effective neuroprotective activity is attributed to HLEA-P1 compound chemically isolated and identified in H. leucospilota ethyl acetate. We reported here that HLEA-P1 could attenuate DAergic neurodegeneration, improve DAergic-dependent behaviors, reduce oxidative stress in 6-OHDA-induced C. elegans. In addition, HLEA-P1 reduced α-synuclein aggregation, improved behavior deficit and recovered lipid deposition in transgenic C. elegans overexpressing α-synuclein. We also found that HLEA-P1 activates nuclear localization of DAF-16 transcription factor of insulin/IGF-1 signaling (IIS) pathway. Treatment with 25 μg/ml of HLEA-P1 upregulated transcriptional activity of DAF-16 target genes including anti-oxidant genes (such as sod-3) and small heat shock proteins (such as hsp16.1, hsp16.2, and hsp12.6) in 6-OHDA-induced worms. In α-synuclein-overexpressed C. elegans strain, treatment with 5 μg/ml of HLEA-P1 significantly activated mRNA expression of sod-3 and hsp16.2. Chemical analysis demonstrated that HLEA-P1 compound is decanoic acid/capric acid. Taken together, our findings revealed that decanoic acid isolated from H. leucospilota exerts anti-Parkinson effect in C. elegans PD models by partly modulating IIS/DAF-16 pathway