Nuclear Spin Relaxation for Higher Spin

We study the relaxation of a spin I that is weakly coupled to a quantum mechanical environment. Starting from the microscopic description, we derive a system of coupled relaxation equations within the adiabatic approximation. These are valid for arbitrary I and also for a general stationary non--equilibrium state of the environment. In the case of equilibrium, the stationary solution of the equations becomes the correct Boltzmannian equilibrium distribution for given spin I. The relaxation towards the stationary solution is characterized by a set of relaxation times, the longest of which can be shorter, by a factor of up to 2I, than the relaxation time in the corresponding Bloch equations calculated in the standard perturbative way.Comment: 4 pages, Latex, 2 figure

First-Line Anti-Tuberculosis Drug Susceptibility Patterns of Mycobacterium tuberculosis Complex Strains Responsible for New Cases of Human Pulmonary Tuberculosis in Kisumu County, Western Kenya

Background: Tuberculosis (TB) remains a major cause of morbidity and mortality worldwide, drug-resistant tuberculosis being a major public health problem. The emergence and spread of multidrug resistant (MDR) Mycobacterium tuberculosis complex (MTBC) strains poses significant challenges to disease control. Continued surveillance of drug susceptibility helps determining proper treatment regimen. The effectiveness of a standard anti-tuberculosis (TB) treatment regimen correlates with in vitro drug susceptibility pattern of the infecting tubercle bacilli. The results of the drug susceptibility tests help select a proper treatment regimen or modify treatment regimen for a better management of patients and surveillance and timely control of the spread of the drug resistant TB in the community. Treatment of drug resistant TB is costly, and the outcomes, including survivorship, can be poor. As the result, the drug susceptibility test has become more important than ever. Objective: This study aimed to investigate the patterns of first line anti-tuberculosis drug-susceptibility against Mycobacterium tuberculosis complex isolates from new cases of pulmonary TB patients in Kisumu County, Western Kenya. Method: This was a cross sectional study which included a total of 290 isolates from pulmonary TB patients in JOOTRH and Kisumu County Hospital between February and August 2016. The MTBC isolates identified were M. tuberculosis, M. africanum, and M. bovis. Drug susceptibility test was performed on the 283 M. tuberculosis, 5 M. africanum and 2 M. bovis isolates by BD BACTEC MGIT 960 SIRE and PZA DST system using five first-line anti-TB drugs: Isoniazid, Rifampicin, Streptomycin, Ethambutol and Pyrazinamide. Results: M. tuberculosis was highly sensitive to all the anti-TB drugs; Streptomycin(S) 96.8%, Isoniazid (H) 89.8%, Rifampin(R) 98.2%, Ethambutol (E) 94.4%, Pyrazinamide (PZA) 89.8%. M. bovis TB species was 100% sensitive to all drug except Pyrazinamide where there was 100% resistance. M. africanum varied in its sensitivity to anti-TB drugs; Streptomycin 80%, Isoniazid 60%), Pyrazinamide 4 (80%). Resistance was Streptomycin 20%, Isoniazid 40%, and Pyrazinamide 20%. M. africanum was neither resistant to Rifampin(R) nor Ethambutol (E). A total of 20.8% of M. tuberculosis strains showed resistance to at least one drug tested, while 79.2% were sensitive. 16.3% were resistant to one drug (mono resistance), 2.1% to two drugs (double resistance), 0.7% to three drugs (triple resistance), 0.4% to four drugs (quadruples) and 1.4% to five drugs (pentagon-resistance). Two isolates of M. bovis were resistant to one drug. Two isolates of M. africanum were resistance, one case to one drug and another one case to three drugs. Conclusion: This study showed high level of resistance in M. tuberculosis isolates warranting proper use of anti-TB drugs in Kisumu County. Keywords: Tuberculosis, M. tuberculosis complex, Multi Drug Resistanc

Molecular Identity of Mycobacteria Isolates in New Cases of Pulmonary Tuberculosis Patients in Kisumu County, Western Kenya

Background: Pulmonary tuberculosis (TB) remains one of the most challenging diseases to control in the world today and it has become a major global health problem especially in immunocompromised people such as HIV/AIDS. The problem is compounded by the emergence of non-tuberculous mycobacteria (NTM) of which its treatment is not directly analogous to that of MTB. Objective: This study determined the identity of Mycobacteria isolates in new cases of human pulmonary TB patients. Methods: It was a cross-sectional study that involved 316 confirmed new cases of pulmonary TB attending JOOTRH and Kisumu County Hospital. Sputa specimen was cultured in MGIT liquid culture medium. The isolates were identified to species level using GenoType® Mycobacterium CM/AS and MTBC Assay from Hain Lifescience Germany. Results. Of the 316 culture positive isolates, 91.8% were identified as MTBC and 8.2% were NTM species. Of the 290 MTBC, three different species were identified, 97.6% were M. tuberculosis, 1.7% were M. africanum and 0.7% were M. bovis. The Fisher’s exact test was used to assess the associations between patient characteristics and MTBC species identified showed that age category of patients less than 35 years and above 35 years were statistically significant with MTBC species (p=0.020). While sex was not statistically significant with MTBC species (p=0.696). Four different NTM species were identified as 61.5% M. intracellulare, 19.2% M. abscessus, 11.5% M. kansasii and 7.7% M. fortuitum. The Fisher’s exact test done to assess the associations between patient characteristics and NTM species was identified. Age category (p=0.608) and sex (p=0.182) of patients was not statistically significant to NTM species. Conclusion: There is a need for routine speciation among members of the MTBC and NTM as it is an important prerequisite for the proper management of patients with mycobacterial infections. Keywords: Mycobacterium tuberculosis complex, Non tuberculous mycobacteria, Tuberculosi

Characterization of doping levels in heteronuclear, gas-phase, van der Waals clusters and their energy absorption from an intense optical field

A simple mass spectrometric method has been developed to quantify dopant levels in heteronuclear clusters in the gas phase. The method is demonstrated with reference to quantification of the water content in supersonic beams of water-doped argon clusters. Such doped clusters have assumed much importance in the context of recently-reported doping-induced enhancement in the emission of energetic charged particles and photons upon their interaction with intense laser pulses. We have also measured the energy that a doped cluster absorbs from the optical field; we find that energy absorption increases with increasing level of doping. The oft-used linear model of energy absorption is found to be quantitatively inadequate.Comment: To appear in Chemical Physics Letter

Cluster formation probability in the trans-tin and trans-lead nuclei

Within our fission model, the Coulomb and proximity potential model (CPPM) cluster formation probabilities are calculated for different clusters ranging from carbon to silicon for the parents in the trans-tin and trans- lead regions. It is found that in trans-tin region the 12^C, 16^O, 20^Ne and 24^Mg clusters have maximum cluster formation probability and lowest half lives as compared to other clusters. In trans-lead region the 14^C, 18, 20^O, 23^F, 24,26^Ne, 28,30^Mg and 34^Si clusters have the maximum cluster formation probability and minimum half life, which show that alpha like clusters are most probable for emission from trans-tin region while non-alpha clusters are probable from trans-lead region. These results stress the role of neutron proton symmetry and asymmetry of daughter nuclei in these two cases.Comment: 20 pages, 6 figure

No Intra-Locus Sexual Conflict over Reproductive Fitness or Ageing in Field Crickets

Differences in the ways in which males and females maximize evolutionary fitness can lead to intra-locus sexual conflict in which genes delivering fitness benefits to one sex are costly when expressed in the other. Trade-offs between current reproductive effort and future reproduction and survival are fundamental to the evolutionary biology of ageing. This leads to the prediction that sex differences in the optimization of age-dependent reproductive effort may generate intra-locus sexual conflict over ageing rates. Here we test for intra-locus sexual conflict over age-dependent reproductive effort and longevity in the black field cricket, Teleogryllus commodus. Using a half-sib breeding design, we show that the most important components of male and female reproductive effort (male calling effort and the number of eggs laid by females) were positively genetically correlated, especially in early adulthood. However, the genetic relationships between longevity and reproductive effort were different for males and females, leading to low genetic covariation between male and female longevity. The apparent absence of intra-locus sexual conflict over ageing suggests that male and female longevity can evolve largely independently of one another

Proximity effect at superconducting Sn-Bi2Se3 interface

We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions down to 250 mK and in different magnetic fields. A number of conductance anomalies were observed below the superconducting transition temperature of Sn, including a small gap different from that of Sn, and a zero-bias conductance peak growing up at lower temperatures. We discussed the possible origins of the smaller gap and the zero-bias conductance peak. These phenomena support that a proximity-effect-induced chiral superconducting phase is formed at the interface between the superconducting Sn and the strong spin-orbit coupling material Bi2Se3.Comment: 7 pages, 8 figure

Demonstration of the temporal matter-wave Talbot effect for trapped matter waves

We demonstrate the temporal Talbot effect for trapped matter waves using ultracold atoms in an optical lattice. We investigate the phase evolution of an array of essentially non-interacting matter waves and observe matter-wave collapse and revival in the form of a Talbot interference pattern. By using long expansion times, we image momentum space with sub-recoil resolution, allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure

Centrality Dependence of the High p_T Charged Hadron Suppression in Au+Au collisions at sqrt(s_NN) = 130 GeV

PHENIX has measured the centrality dependence of charged hadron p_T spectra from central Au+Au collisions at sqrt(s_NN)=130 GeV. The truncated mean p_T decreases with centrality for p_T > 2 GeV/c, indicating an apparent reduction of the contribution from hard scattering to high p_T hadron production. For central collisions the yield at high p_T is shown to be suppressed compared to binary nucleon-nucleon collision scaling of p+p data. This suppression is monotonically increasing with centrality, but most of the change occurs below 30% centrality, i.e. for collisions with less than about 140 participating nucleons. The observed p_T and centrality dependence is consistent with the particle production predicted by models including hard scattering and subsequent energy loss of the scattered partons in the dense matter created in the collisions.Comment: 7 pages text, LaTeX, 6 figures, 2 tables, 307 authors, resubmitted to Phys. Lett. B. Revised to address referee concerns. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm