Physical Interpretation of Laser-Induced Suppression of Quantum Tunneling

We revisit the problem of laser-induced suppression of quantum dynamical tunneling in a model system studied by Kilin et al. [Phys. Rev. Lett. 76 (1996) 3297]. This quantum system consists of a ground state symmetric double-well potential which is coupled by a strong laser field to an excited state asymmetric double-well potential. By analyzing the assumptions used in their analysis we show that the suppression of quantum dynamical tunneling can be explained with the use of dark and bright states of the system. We also generalize the system and the conditions for suppression of quantum tunneling and show that, in certain cases, suppression can occur regardless the characteristics of the excited potential surface.Comment: 4 pages text, 1 figure. Submitted for publicatio

Analysing The Major Effects Of Exports And Imports On The Balance Of Foreign Trade In Ghana

This paper presents analysing the major effects of exports and imports on the balance of foreign trade in Ghana. The study made used of principal component analysis (PCA), multiple linear regression analysis and stepwise regression analysis to find out which export and import commodities have significant effects on the balance of foreign trade in Ghana. The sampling test conducted using the Mineigen criteria of 0.25 in absolute values. Data was sought from Ghana Statistical Service (GSS) trade statistics division. The data was divided into three groups, food, textile and manufacturing. The analysis shows that, the first group which is food, cocoa beans has significant effect on balance of trade on exports while rice has effect on imports. For the second group which is textile, kente also has significant effect on exports and boxes on imports for balance of trade in Ghana. The final group is manufacturing has monetary gold and aluminum sheet having effect on exports while that of buckets, shovels and gribs of machines  have effect on imports of balance of trade in Ghana. The gap between exports and imports with regard to food commodities is closing especially export while that of manufacturing commodities is increasing. In this paper the balance of trade considered goods only. Key words: Principal Component (PCA), Stepwise Regression Analysis, Multiple Linear Regressions Analysis, ANOV

Subcultural tensions in managing organisational culture:a study of an English Premier League football organisation

In this article, we explore subcultural interaction in the context of attempts by executives to control culture in the unusual organisational setting of football. We present evidence of five tension points in subcultural relations (togetherness or isolation, internal labour market, multiple identification and allegiances, individual and organisational requirements, and competition and cooperation). We examine how these tensions were induced and or exacerbated by the culture management efforts, as well as the ways in which the dynamics of change impacted on the objectives of executives. The article concludes with a discussion of the implications of the findings for theory and practice

Ethnic Gatekeeping on the Shopfloor:A Study of Bases, Motives and Approaches

Recent contributions on the discrimination of black and minority ethnic (BME) groups in organizations have suggested that overt forms of discrimination are now ‘old-fashioned’ and researchers are urged to focus on identifying different, ‘modern’ forms of discrimination. These are, however, set against studies that continue to report evidence of overt racism in organizations. This article argues that it may be premature and potentially counterproductive to celebrate the demise of overt discrimination in that such binary classification (‘old-fashioned’ and ‘modern’) may discourage efforts to investigate the full gamut of experiences of BME groups. The article contends that additional insights will be gained by concurrently studying not only the victims and the perpetrators of discrimination but also the organizational context in which discrimination occurs. Through the theoretical lens of gatekeeping, the article presents evidence of shopfloor discrimination against BME groups that is neither fully overt nor entirely covert

Real particle physics analysis by UK secondary school students using the ATLAS Open Data: an illustration through a collection of original student research

Since the 2020 release of 10fb-1 of integrated luminosity of proton–proton collision data to the public by the ATLAS experiment, significant potential for its use for youth engagement in physics and citizen science has been present. In particular, this article aims to address whether, if provided adequate training and resources, high school students are capable of leveraging the ATLAS Open Data to semi-autonomously develop their own original research projects. To this end, a repository of interactive Python Jupyter notebook training materials was developed, incrementally increasing in difficulty; in the initial instalments no prior knowledge of particle physics or Python coding is assumed, while in the latter stages students emulate the steps of a real Higgs boson search using ATLAS data. This programme was implemented in secondary schools throughout the UK during the 2022/23 academic year and is presented in this article through a collection of research projects developed by a selection of participating students

Haematological and Hepatological effects of Pito, Burukutu-Guinea corn and Burukutu-Millet in Albino Rats

This study investigated the haematological and hepatological effects of selected locally brewed beers in albino rats. Three locally brewed beers were purchased from locally brewed beer joint in Wukari, Nigeria. Twenty male albino rats were used and were randomly distributed into four groups of five rats each. Group 1 served as normal control, while groups 2, 3 and 4 were administered pito, burukutu-Guinea corn and burukutu-millet (10mL/kg bwt) respectively for 21 days before being sacrificed. Result showed that ALT and AST activities increased in all the groups administered the different beer compared to the control. Cholesterol increased in group 2, but decreased in group 4. Potassium and glucose reduced in all test groups compared to the normal control. The differences in cholesterol, potassium and glucose levels are statistically less-significant (p>0.05) compared to the control. The liver histoarchitectural state of the test animals administered the beers compared to the control animals showed the beers had toxic effect on the animals. There is evidence of infiltration and distortion of some regions of the liver tissue in the test animals. This agrees with the results of serum biochemical parameters evaluated. The WBC, LYM and GRA increased in group 3 and reduced in groups 2 and 4 compared to the control. The MID reduced in all the test groups compared to the control. RBC, Hb and HCT increased in all the test groups compared to the control. The MCV increased only in group 4 and decreased in groups 2 and 3. The MCH, MCHC and RDWc reduced in all the test groups, while PLT, PCT, MPV and PDWc increased in all the test groups compared to the control. This study has shown that constant administration of pito, burukutu-guinea corn and burukutu-millet in the test animals for a long duration caused alterations and negative effect on the liver function, but may not interfere negatively with the Hb and RBC count

Orbiting pairs of walking droplets: Dynamics and stability

A decade ago, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)]PRLTAO0031-900710.1103/PhysRevLett.97.154101 discovered that a millimetric droplet sustained on the surface of a vibrating fluid bath may self-propel through a resonant interaction with its own wave field. We here present the results of a combined experimental and theoretical investigation of the interactions of such walking droplets. Specifically, we delimit experimentally the different regimes for an orbiting pair of identical walkers and extend the theoretical model of Oza [J. Fluid Mech. 737, 552 (2013)] JFLSA70022-112010.1017/jfm.2013.581 in order to rationalize our observations. A quantitative comparison between experiment and theory highlights the importance of spatial damping of the wave field. Our results also indicate that walkers adapt their impact phase according to the local wave height, an effect that stabilizes orbiting bound states.National Science Foundation (U.S.) (Grant CMMI-1333242)National Science Foundation (U.S.) (Grant DMS-1614043

Serotonergic psychedelics LSD & psilocybin increase the fractal dimension of cortical brain activity in spatial and temporal domains.

Psychedelic drugs, such as psilocybin and LSD, represent unique tools for researchers investigating the neural origins of consciousness. Currently, the most compelling theories of how psychedelics exert their effects is by increasing the complexity of brain activity and moving the system towards a critical point between order and disorder, creating more dynamic and complex patterns of neural activity. While the concept of criticality is of central importance to this theory, few of the published studies on psychedelics investigate it directly, testing instead related measures such as algorithmic complexity or Shannon entropy. We propose using the fractal dimension of functional activity in the brain as a measure of complexity since findings from physics suggest that as a system organizes towards criticality, it tends to take on a fractal structure. We tested two different measures of fractal dimension, one spatial and one temporal, using fMRI data from volunteers under the influence of both LSD and psilocybin. The first was the fractal dimension of cortical functional connectivity networks and the second was the fractal dimension of BOLD time-series. In addition to the fractal measures, we used a well-established, non-fractal measure of signal complexity and show that they behave similarly. We were able to show that both psychedelic drugs significantly increased the fractal dimension of functional connectivity networks, and that LSD significantly increased the fractal dimension of BOLD signals, with psilocybin showing a non-significant trend in the same direction. With both LSD and psilocybin, we were able to localize changes in the fractal dimension of BOLD signals to brain areas assigned to the dorsal-attenion network. These results show that psychedelic drugs increase the fractal dimension of activity in the brain and we see this as an indicator that the changes in consciousness triggered by psychedelics are associated with evolution towards a critical zone.NIHR Wellcome NSF-NRT MRC Beckley Foundation Alex Mosley Charitable Trust Ad Astria Chandaria Foundation. Neuro-psychoanalysis Foundation Multidisplinary Association for Psychedelic Studies The Heffter Research Institut

Uncovering the formation of ultra-compact dwarf galaxies by multivariate statistical analysis

We present a statistical analysis of the properties of a large sample of dynamically hot old stellar systems, from globular clusters to giant ellipticals, which was performed in order to investigate the origin of ultra-compact dwarf galaxies. The data were mostly drawn from Forbes et al. (2008). We recalculated some of the effective radii, computed mean surface brightnesses and mass-to-light-ratios, estimated ages and metallicities. We completed the sample with globular clusters of M31. We used a multivariate statistical technique (K-Means clustering), together with a new algorithm (Gap Statistics) for finding the optimum number of homogeneous sub-groups in the sample, using a total of six parameters (absolute magnitude, effective radius, virial mass-to-light ratio, stellar mass-to-light ratio and metallicity). We found six groups. FK1 and FK5 are composed of high- and low-mass elliptical galaxies respectively. FK3 and FK6 are composed of high-metallicity and low-metallicity objects, respectively, and both include globular clusters and ultra-compact dwarf galaxies. Two very small groups, FK2 and FK4, are composed of Local Group dwarf spheroidals. Our groups differ in their mean masses and virial mass-to-light ratios. The relations between these two parameters are also different for the various groups. The probability density distributions of metallicity for the four groups of galaxies is similar to that of the globular clusters and UCDs. The brightest low-metallicity globular clusters and ultra-compact dwarf galaxies tend to follow the mass-metallicity relation like elliptical galaxies. The objects of FK3 are more metal-rich per unit effective luminosity density than high-mass ellipticals.Comment: Accepted for publication in Astrophysical Journa