Numerically Computing QCD Laplace Sum-Rules Using pySecDec

pySecDec is a program that numerically calculates dimensionally regularized integrals. We use pySecDec to compute QCD Laplace sum-rules for pseudoscalar (i.e., $J^{PC}=0^{-+}$) charmonium hybrids, and compare the results to sum-rules computed using analytic results for dimensionally regularized integrals. We find that the errors due to the use of numerical integration methods is negligible compared to the uncertainties in the sum-rules stemming from the uncertainties in the parameters of QCD, e.g., the coupling constant, quark masses, and condensate values. Also, we demonstrate that numerical integration methods can be used to calculate finite-energy and Gaussian sum-rules in addition to Laplace sum-rules.Comment: 10 pages, 5 figure

Young People's Social Networks, Confidants and Issues of Reproductive Health

This qualitative micro study was conducted in the Metropole of Cape Town, the third largest metropole in South Africa during 2002. The study must be seen in relation to the Cape Area Panel Study (CAPS) that was conducted in June 2002. CAPS is planned as a longitudinal data collection project aimed at the youth in the Cape Metropole. The panel study broadly aims to supplement existing data sets like the Census, October Household Survey [OHS], Labour Force Survey [LFS] in particular with longitudinal and qualitative data addressing areas not necessarily done by national surveys. It anticipates uncovering determinants of schooling, unemployment and earnings of young adults and youth in this part of the country. Adolescent childbearing is common in South Africa as demonstrated by the 1998 South Africa Demographic and Health Survey, where by the age of 19 years, 30 percent of teenage females have had a child, 35 percent have been pregnant and the majority of teenage childbearing is outside of marriage. [Department of Health 1999] Given the high prevalence of pregnancy and unmarried childbearing among adolescent females, it becomes important to understand the degree to which young people themselves understand how pregnancy and childbearing in adolescence delay or disrupt other life course events such as school completion or entering into marriage or cohabitation. Drawing on focus group discussion data from teenagers in Cape Town on normatively appropriate sequences, we note the degree to which the actual ways teenage males and females move through adolescence depart from the normative sequences.

The Links Between Migration, Poverty and Health: Evidence From Khayelitsha and Mitchell's Plain

In the mid-1950s, the City of Cape Town was part of a wider area demarcated as a Coloured Labour Preference Area. The free movement of African people into the city was strictly controlled and the residential areas were segregated along racial lines. In terms of Apartheid's grand design, an area designated Mitchell's Plain was demarcated for occupation by Coloured people in 1973 while another designated Khayelitsha was allocated for African people. The two areas were incorporated in one magisterial district, Mitchell's Plain, in the mid-1980s. A sample survey of the area was conducted in late November and early December 2000 with a focus on labour market issues. Its aim was to capture occupants of households aged 18 or older. The survey data has been interrogated to describe the connections between migration, poverty and health in a city where recent rapid urbanisation is changing the demographic profile significantly. As a consequence, the need to provide adequate infrastructure, decent housing and employment poses a daunting challenge ten years after the new democracy has been ushered in.

Line and continuum radiative transfer modelling of AA Tau

We present photometric and spectroscopic models of the Classical T Tauri star AA Tau. Photometric and spectroscopic variability present in observations of AA Tau is attributed to a magnetically induced warp in the accretion disc, periodically occulting the photosphere on an 8.2--day timescale. Emission line profiles show signatures of both infall, attributed to magnetospherically accreting material, and outflow. Using the radiative transfer code TORUS, we have investigated the geometry and kinematics of AA Tau's circumstellar disc and outflow, which is modelled here as a disc wind. Photometric models have been used to constrain the aspect ratio of the disc, the offset angle of the magnetosphere dipole with respect to the stellar rotation axis, and the inner radius of the circumstellar disc. Spectroscopic models have been used to constrain the wind and magnetosphere temperatures, wind acceleration parameter, and mass loss rate. We find observations are best fitted by models with a mass accretion rate of $5\times10^{-9}$ M$_\odot$ yr$^{-1}$, a dipole offset of between $10^\circ$ and $20^\circ$, a magnetosphere that truncates the disc from 5.2 to 8.8 R$_\star$, a mass-loss-rate to accretion-rate ratio of ~ 0.1, a magnetosphere temperature of 8500 -- 9000 K, and a disc wind temperature of 8000 K.Comment: 22 pages, 32 figures, 4 tables. Accepted by MNRAS. V3: Corrected typ

Evaluation of exercises designed to increase the children's use of descriptive words in written expression.

Thesis (M.A.)--Boston Universit

Turbulentne strukture većih dimenzija u Ekmanovom graničnom sloju

The Ekman boundary layer (EBL) is a non-stratifi ed turbulent layer of fluid in a rotated frame of reference. The EBL comprises two sub-layers, namely, the surface sub-layer, where small scale well-developed turbulence dominates, and the core sub-layer, where large scale self-organized turbulence dominates. This study reports self-organization of large scale turbulence in the EBL as simulated with the large-eddy simulation (LES) model LESNIC. The simulations were conducted in a large domain (144 km in the cross-flow direction, which is an equivalent to about 50 EBL depths) to resolve statistically signifi cant number of the largest self-organized eddies. Analysis revealed that the latitude of the LES domain and, unexpectedly, the direction of the geostrophic wind forcing control the self-organization, turbulence scales, evolution and the quasi steady-state averaged vertical profi les in the EBL. The LES demonstrated destabilization of the EBL turbulence and its mean structure by the horizontal component of the Coriolis force. Visualisations of the EBL disclosed existence of quasi-regular large scale turbulent structures composed of counter-rotating vortices when the geostrophic fl ow was set from East to West. The corresponding structures are absent in the EBL when the geostrophic fl ow was set in the opposite (i.e. West to East) direction. These results fi nally resolve the long-standing controversy between the Leibovich-Lele and the Lilly-Brown instability mechanisms acting in the EBL. The LES demonstrated that the Lilly-Brown mechanism, which involves the vertical component of the Coriolis force, is working in the polar EBL where its impact is nevertheless rather small. The Leibovich-Lele mechanism, which involves the horizontal component of the Coriolis force, acts in low latitudes where it completely alters the turbulent structure of the EBL.Ekmanov granični sloj (EGS) je nestratificirani turbulentni sloj u rotirajućem fluidu. EGS se učestalo opaža i u atmosferi i u oceanu. Sastoji se od dva podsloja: od površinskog,u kojem dominira dobro razvijena turbulencija male skale, i središnjeg, u kojem dominira samoorganizirana turbulencija veće skale. Ova studija prikazuje samoorganiziranuturbulenciju veće skale u EGS-u, koja je simulirana modelom velikihx vrtloga (LES)nazvanim LESNIC. Kako bi se odredio statistički značajan broj najvećih samoorganiziranih vrtloga, simulacije su rađene na velikoj domeni (144 km u smjeru okomitom na strujanje, što približno odgovara pedeseterostrukoj debljini EGS-a). Analiza je pokazala dazemljopisna širina LES domene i, neočekivano, smjer forsirajućeg geostrofičkog vjetra kontroliraju samoorganiziranost, skale turbulencije, razvoj i kvazistacionarno stanjeusrednjenih vertikalnih profila u EGS-u. LES rezultati su pokazali destabilizaciju EGSturbulencije i njene srednje strukture s horizontalnom komponentom Coriolisove sile.Vizualizacija EGS-a je otkrila postojanja skoro pravilnih turbulentnih struktura velikeskale, koje su se u slučaju promjene geostrofičkog vjetra od istočnog u zapadni, sastojaleod vrloga sa suprotnom rotacijom. Odgovarajuće strukture nisu bile prisutne u EGS-uukoliko je vjetar mijenjan u suprotnom smjeru (od zapada prema istoku). Ovi rezultati ukonačnici rješavaju dugo prisutnu polemiku između Leibovich-Leleovog i Lilly-Brownovogmehanizma nestabilnosti, koji djeluju u EGS-u. LES simulacije pokazuju da Lilly-Brownovmehanizam, koji uključuje vertikalnu komponentu Coriolisove sile, vrijedi u polarnomEGS-u, gdje je njegov utjecaj ipak malen. Leibovich-Leleov mehanizam, koji uključujehorizontalnu komponentu Coriolisove sile, djeluje na nižim zemljopisnim širinama, gdjeu potpunosti mijenja turbulentnu strukturu EGS

Teaching Professional Responsibility in Law School

After eight years of teaching a three-credit course on The Legal Profession and Professional Responsibility to second- and third-year law students, I am left with a sense of great dissatisfaction with the whole enterprise. So deep is my dissatisfaction that I am questioning whether to continue or move into a different course instead. This paper is an opportunity to take stock of my experience and attempt to map out the causes of my dissatisfaction, and to seek some vision, if possible, of what the course should be about, how to teach it, and why I should bother. To give the conclusion away, I have in this process arrived at the point of renewed hope, even though many problems remain unresolved and many ideals remain to be actualized. The professional responsibility course may be the most problematic one I teach, but I also think it is the most important, and perhaps one day will even be the most personally fulfilling