EUROPEAN UNION ENLARGEMENT: WHAT ARE THE AGRICULTURAL TRADE MODELS MISSING?

This paper quantifies the potential impact of European Union enlargement and the consequences of ignoring the non-agricultural component of this integration. We find that agriculture-focused studies offer sound estimates of agriculture-specific production and trade changes, but the estimates of trade volume changes, and welfare gains are far too low.International Relations/Trade,

Dynamics of circular arrangements of vorticity in two dimensions

The merger of two like-signed vortices is a well-studied problem, but in a turbulent flow, we may often have more than two like-signed vortices interacting. We study the merger of three or more identical co-rotating vortices initially arranged on the vertices of a regular polygon. At low to moderate Reynolds numbers, we find an additional stage in the merger process, absent in the merger of two vortices, where an annular vortical structure is formed and is long-lived. Vortex merger is slowed down significantly due to this. Such annular vortices are known at far higher Reynolds numbers in studies of tropical cyclones, which have been noticed to a break down into individual vortices. In the pre-annular stage, vortical structures in a viscous flow are found here to tilt and realign in a manner similar to the inviscid case, but the pronounced filaments visible in the latter are practically absent in the former. Interestingly at higher Reynolds numbers, the merger of an odd number of vortices is found to proceed very differently from that of an even number. The former process is rapid and chaotic whereas the latter proceeds more slowly via pairing events. The annular vortex takes the form of a generalised Lamb-Oseen vortex (GLO), and diffuses inwards until it forms a standard Lamb-Oseen vortex. For lower Reynolds number, the numerical (fully nonlinear) evolution of the GLO vortex follows exactly the analytical evolution until merger. At higher Reynolds numbers, the annulus goes through instabilities whose nonlinear stages show a pronounced difference between even and odd mode disturbances. It is hoped that the present findings, that multiple vortex merger is qualitatively different from the merger of two vortices, will motivate studies on how multiple vortex interactions affect the inverse cascade in two-dimensional turbulence.Comment: Abstract truncated. Paper to appear in Physical Review

Observations on TeV gamma rays from Geminga and PSR 0950+08

The Geminga (2 CG 195+04) which exhibits a periodicity with a period of 59 to 60 s in its emission of X-rays, GeV gamma rays and TeV gamma rays was studied. During the winter of 1984 to 1985, this object was observed to see if it emits TeV gamma rays with a periodicity approx 60 s. The observations were carried out at two different sites separated by 11 Km with the Ooty Atmospheric Cerenkov Array split into two parts. Data were collected during clear moonless nights for a total duration of 15.3 hours spread over 2 months. Since the first time derivative of period is believed to be large and uncertain. The total data are subdivided into segments of duration not more than 3 days each to steer clear of the effects of P in the phase analysis. If TeV gamma ray signals are seen in each of these segments, it is possible to derive P from observed data

Reduced Exercise Capacity in Non-Cystic Fibrosis Bronchiectasis

Objective : Bronchiectasis not due to cystic fibrosis is usually a consequence of severe bacterial or tuberculous infection of the lungs, which is commonly seen in children in developing countries. Our aim was to study its functional sequelae and affect on work capacity in children. Methods : Seventeen children (7-17 years of age) with clinical and radiological evidence of bronchiectasis of one or both lungs were studied at the Cardiopulmonaly Unit of the Tuberculosis Research Centre. Pulmonary function tests including spirometry and lung volume measurements were performed. Incremental exercise stress test was done on a treadmill, and ventilatory and cardiac parameters we monitored. Control values were taken from a previous study. Results : Children with bronchiectasis had lower forced vital capacity (FVC) (1.1 + 0.4 L versus 1.5 + 0.4 L, p=0.003) and FEV1 (0.95 ± 0.2 L versus 1.4 ± 0.3 L, p<0.002) compared to age- and sex-matched healthy controls. The patient group had significantly higher residual lung volumes (0.7 ± 0.3 L versus 0.4 + 0.1 L, p<0.02). At maximal exercise, they had lower aerobic capacity (28 ± 6 ml/min/kg versus 38 5 ml/min/kg, p<0.0001) and maximal ventilation (24 ± 8 L/min versus 39 ± 10 L/min, p<0.001). At maximal exercise, while none of the controls desaturated, oxygen saturation fell below 88% in eight of 17 patients. conclusion ;The findings show that children and adolescents with non-cystic fibrosis bronchiectasis have abnormal pulmonary function and reduced exercise capacity. This is likely to interfere with their lie as well as future work capacity. Efforts should be made to minimize lung damage in childhood by ensuring early diagnosis and instituting appropriate treatment of respiratory infections

Electron-impact excitation of X 1Sigma_g⁺(v[double-prime]=0) to the a[double-prime] 1Sigma_g⁺, b 1Piu, c3 1Piu, o3 1Piu, b[prime] 1Sigma_u⁺, c₄^[prime] 1Sigma_u⁺, G 3Piu, and F 3Piu states of molecular nitrogen

Measurements of differential cross sections (DCSs) for electron-impact excitation of the a[double-prime] 1Sigmag+, b 1Piu, c3 1Piu, o3 1Piu, b[prime] 1Sigmau+, c4[prime] 1Sigmau+, G 3Piu, and F 3Piu states in N2 from the X 1Sigmag+(v[double-prime]=0) ground level are presented. The DCSs were obtained from energy-loss spectra in the region of 12 to 13.82 eV measured at incident energies of 17.5, 20, 30, 50, and 100 eV and for scattering angles ranging from 2° to 130°. The analysis of the spectra follows a different algorithm from that employed in a previous study of N2 for the valence states [Khakoo et al. Phys. Rev. A 71, 062703 (2005)], since the 1Piu and 1Sigmau+ states form strongly interacting Rydberg-valence series. The results are compared with existing data

Aerobic capacity and cardio-pulmonary responses to exercise in healthy South Indian children

Objective: To examine the cardiorespiratory response to exercise in healthy South Indian school children. Design: Prospective study. Setting: Cardiopulmo nary Medicine Unit, Tuberculosi s Research Center, Ma dras. Subjects: Data was obtained on 47 girls an d 48 boys in the age group 7 to 14 years. Intervention: The children performed a graded maximal exercise stress test on a compute rized treadmill system. Results: Maximum oxygen consumption (VO2max) increased significa ntly at 11 years of a ge in both sexes b ut while boys sho wed a progressive increase beyond 11 years, girls did not. When corrected for weight , only boys at 14 years had a significant increase in VO2max/kg. Boys had higher values of VO2max/kg than girls at all ages. Minute venti lation and oxygen pulse values also increased in both sexes at 11 to 12 year s. The VO2max of South Indian children was lower than the predicte d values available for North American children w hen prediction equations based on height were used. However, when regression equations based on weight were used, the predicted values for North American and South Indian boys were similar, though values for the Indian girls were still low. Nutri tional and sociocul tural factors may play a role in determining VO2max of children from different pop ulations, rather than ethnic differences alone. significa ntly at 11 years of a ge in both sexes b ut while boys sho wed a progressive increase beyond 11 years, girls did not. When corrected for weight , only boys at 14 years had a significant increase in VO2max/kg. Boys had higher values of VO2max/kg than girls at all ages. Minute venti lation and oxygen pulse values also increased in both sexes at 11 to 12 year s. The VO2max of South Indian children was lower than the predicte d values available for North American children w hen prediction equations based on height were used. However, when regression equations based on weight were used, the predicted values for North American and South Indian boys were similar, though values for the Indian girls were still low. Conclusions: Nutri tional and sociocul tural factors may play a role in determining VO2max of children from different populations, rather than ethnic differences alone

Influence of Zn doping profiles on excitation dependence of photoluminescence intensity in InGaAsP heterostructures

It is known that the Zn doping profile in strained multi-quantum-well (MQW) InGaAsP lasers strongly affects the electro-optical characteristics of these devices and their temperature sensitivity. A systematic investigation of the excitation dependence of the active layer photoluminescence (PL) intensity from compressively strained InGaAsP MQW pin laser material with different Zn doping profiles is described. When the pn junction lies within the active region, the excitation dependence of the PL intensity is superlinear at low excitation and linear at higher excitation. As the Zn profile is set back from the heterointerface creating a displaced pn junction from the active region, the excitation dependence is superlinear and linear at 300 K but becomes linear for all excitation powers at 77 K. The implications of these observations are discussed