Decaying neutron propagation in the Galaxy and the Cosmic Ray anisotropy at 1 EeV

We study the cosmic ray arrival distribution expected from a source of neutrons in the galactic center at energies around 1 EeV and compare it with the anisotropy detected by AGASA and SUGAR. Besides the point-like signal in the source direction produced by the direct neutrons, an extended signal due to the protons produced in neutron decays is expected. This associated proton signal also leads to an excess in the direction of the spiral arm. For realistic models of the regular and random galactic magnetic fields, the resulting anisotropy as a function of the energy is obtained. We find that for the anisotropy to become sufficiently suppressed below E\sim 10^{17.9}eV, a significant random magnetic field component is required, while on the other hand, this also tends to increase the angular spread of the associated proton signal and to reduce the excess in the spiral arm direction. The source luminosity required in order that the right ascension anisotropy be 4% for the AGASA angular exposure corresponds to a prediction for the point-like flux from direct neutrons compatible with the flux detected by SUGAR. We also analyse the distinguishing features predicted for a large statistics southern observatory.Comment: 14 pages, 6 figures, minor changes to match published versio

Lawsone Unleashed: A Comprehensive Review on Chemistry, Biosynthesis, and Therapeutic Potentials

Aathira Sujathan Nair,1 Mahendran Sekar,1 Siew Hua Gan,1 Vinoth Kumarasamy,2 Vetriselvan Subramaniyan,3 Yuan Seng Wu,4 Nur Najihah Izzati Mat Rani,5 Subban Ravi,6 Ling Shing Wong7 1School of Pharmacy, Monash University Malaysia, Bandar Sunway, Subang Jaya, Selangor, 47500, Malaysia; 2Department of Parasitology & Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, 56000, Malaysia; 3Department of Medical Sciences, School of Medical and Life Sciences, Sunway University, Bandar Sunway, Selangor, 47500, Malaysia; 4Sunway Microbiome Centre & Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Bandar Sunway, Selangor, 47500, Malaysia; 5Faculty of Pharmacy and Health Sciences, Royal College of Medicine Perak, Universiti Kuala Lumpur, Ipoh, Perak, 30450, Malaysia; 6Department of Chemistry, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, India; 7Faculty of Health and Life Sciences, INTI International University, Nilai, 71800, MalaysiaCorrespondence: Mahendran Sekar, School of Pharmacy, Monash University Malaysia, Bandar Sunway, Subang Jaya, Selangor, 47500, Malaysia, Email [email protected] Vinoth Kumarasamy, Department of Parasitology & Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Cheras, Kuala Lumpur, 56000, Malaysia, Email [email protected]: Lawsone, a naturally occurring organic compound also called hennotannic acid, obtained mainly from Lawsonia inermis (Henna). It is a potential drug-like molecule with unique chemical and biological characteristics. Traditionally, henna is used in hair and skin coloring and is also a medicinal herb for various diseases. It is also widely used as a starting material for the synthesis of various drug molecules. In this review, we investigate on the chemistry, biosynthesis, physical and biological properties of lawsone. The results showed that lawsone has potential antioxidant, anti-inflammatory, antimicrobial and antitumor properties. It also induces cell cycle inhibition and programmed cell death in cancer, making it a potential chemotherapeutic agent. Additionally, inhibition of pro-inflammatory cytokine production makes it an essential treatment for inflammatory diseases. Exploration of its biosynthetic pathway can pave the way for its development into targets for new drug development. In future, well-thought-out clinical studies should be made to verify its safety and efficacy. Keywords: lawsone, Lawsonia inermis, henna, antitumor, antioxidant, anti-inflammatory, antimicrobia

The Hubble Constant

I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give $H_0$ values of around 72-74km/s/Mpc , with typical errors of 2-3km/s/Mpc. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68km/s/Mpc and typical errors of 1-2km/s/Mpc. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.Comment: Extensively revised and updated since the 2007 version: accepted by Living Reviews in Relativity as a major (2014) update of LRR 10, 4, 200

The evolution of rotating stars

First, we review the main physical effects to be considered in the building of evolutionary models of rotating stars on the Upper Main-Sequence (MS). The internal rotation law evolves as a result of contraction and expansion, meridional circulation, diffusion processes and mass loss. In turn, differential rotation and mixing exert a feedback on circulation and diffusion, so that a consistent treatment is necessary. We review recent results on the evolution of internal rotation and the surface rotational velocities for stars on the Upper MS, for red giants, supergiants and W-R stars. A fast rotation is enhancing the mass loss by stellar winds and reciprocally high mass loss is removing a lot of angular momentum. The problem of the ``break-up'' or $\Omega$-limit is critically examined in connection with the origin of Be and LBV stars. The effects of rotation on the tracks in the HR diagram, the lifetimes, the isochrones, the blue to red supergiant ratios, the formation of W-R stars, the chemical abundances in massive stars as well as in red giants and AGB stars, are reviewed in relation to recent observations for stars in the Galaxy and Magellanic Clouds. The effects of rotation on the final stages and on the chemical yields are examined, as well as the constraints placed by the periods of pulsars. On the whole, this review points out that stellar evolution is not only a function of mass M and metallicity Z, but of angular velocity $\Omega$ as well.Comment: 78 pages, 7 figures, review for Annual Review of Astronomy and Astrophysics, vol. 38 (2000

The Development and Validation of the Thai-Translated Irrational Performance Beliefs Inventory (T-iPBI)

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. One of the most commonly employed cognitive-behavioural approaches to psychotherapy is rational-emotive behaviour therapy, but researchers have been troubled by some of the limitations of irrational beliefs psychometrics. As a result, Turner et al. (Eur J Psychol Assess 34:174–180, 2018a. https://doi.org/10.1027/1015-5759/a000314) developed the Irrational Performance Beliefs Inventory (iPBI), a novel measure of irrational beliefs for use within performance domains. However, the linguistic and cross-cultural adaptation of the iPBI into other languages is necessary for its multinational and multicultural use. The purpose of this paper is to develop the Thai-translated version of the iPBI (T-iPBI) and examine the validity and reliability of the T-iPBI. Data retrieved from 166 participants were analysed using SPSS and AMOS software packages. Thirty-three participants completed two follow-up T-iPBI measurements (1- and 3-week repeat assessment). After the linguistic and cross-cultural adaptation processes, the T-iPBI demonstrated excellent levels of reliability, with internal consistency and test–retest reliability, as well as construct, concurrent, and predictive validity. The current findings indicate that the 20-item T-iPBI can be used as a self-assessment instrument to evaluate individual’s irrational performance beliefs in a Thai population. We also highlight the implications of this study and suggest a variety of future research directions that stem from the results

Gendered dimensions of obesity in childhood and adolescence

BACKGROUND: The literature on childhood and adolescent obesity is vast. In addition to producing a general overview, this paper aims to highlight gender differences or similarities, an area which has tended not to be the principal focus of this literature. METHODS: Databases were searched using the terms 'obesity' and 'child', 'adolescent', 'teenager', 'youth', 'young people', 'sex', 'gender', 'masculine', 'feminine', 'male', 'female', 'boy' and 'girl' (or variations on these terms). In order to limit the potential literature, the main focus is on other reviews, both general and relating to specific aspects of obesity. RESULTS: The findings of genetic studies are similar for males and females, and differences in obesity rates as defined by body mass index are generally small and inconsistent. However, differences between males and females due to biology are evident in the patterning of body fat, the fat levels at which health risks become apparent, levels of resting energy expenditure and energy requirements, ability to engage in certain physical activities and the consequences of obesity for the female reproductive system. Differences due to society or culture include food choices and dietary concerns, overall physical activity levels, body satisfaction and the long-term psychosocial consequences of childhood and adolescent obesity. CONCLUSION: This review suggests differences between males and females in exposure and vulnerability to obesogenic environments, the consequences of child and adolescent obesity, and responses to interventions for the condition. A clearer focus on gender differences is required among both researchers and policy makers within this field

Traditional Excluding Forces: A Review of the Quantitative Literature on the Economic Situation of Indigenous Peoples, Afro-Descendants, and People Living with Disability

Unequal income distribution in Latin America and the Caribbean is linked to unequal distributions of (human and physical) assets and differential access to markets and services. These circumstances, and the accompanying social tensions, need to be understood in terms of traditional fragmenting forces; the sectors of the population who experience unfavorable outcomes are also recognized by characteristics such as ethnicity, race, gender and physical disability. In addition to reviewing the general literature on social exclusion, this paper surveys several more specific topics: i) relative deprivation (in land and housing, physical infrastructure, health and income); ii) labor market issues, including access to labor markets in general, as well as informality, segregation and discrimination; iii) the transaction points of political representation, social protection and violence; and iv) areas where analysis remains weak and avenues for further research in the region

Production of dust by massive stars at high redshift

The large amounts of dust detected in sub-millimeter galaxies and quasars at high redshift pose a challenge to galaxy formation models and theories of cosmic dust formation. At z > 6 only stars of relatively high mass (> 3 Msun) are sufficiently short-lived to be potential stellar sources of dust. This review is devoted to identifying and quantifying the most important stellar channels of rapid dust formation. We ascertain the dust production efficiency of stars in the mass range 3-40 Msun using both observed and theoretical dust yields of evolved massive stars and supernovae (SNe) and provide analytical expressions for the dust production efficiencies in various scenarios. We also address the strong sensitivity of the total dust productivity to the initial mass function. From simple considerations, we find that, in the early Universe, high-mass (> 3 Msun) asymptotic giant branch stars can only be dominant dust producers if SNe generate <~ 3 x 10^-3 Msun of dust whereas SNe prevail if they are more efficient. We address the challenges in inferring dust masses and star-formation rates from observations of high-redshift galaxies. We conclude that significant SN dust production at high redshift is likely required to reproduce current dust mass estimates, possibly coupled with rapid dust grain growth in the interstellar medium.Comment: 72 pages, 9 figures, 5 tables; to be published in The Astronomy and Astrophysics Revie