Controlled generation of field squeezing with cold atomic clouds coupled to a superconducting transmission line resonator

We propose an efficient method for controlled generation of field squeezing with cold atomic clouds trapped close to a superconducting transmission line resonator. It is shown that, based on the coherent strong magnetic coupling between the collective atomic spins and microwave fields in the transmission line resonator, two-mode or single mode field squeezed states can be generated through coherent control on the dynamics of the system. The degree of squeezing and preparing time can be directly controlled through tuning the external classical fields. This protocol may offer a promising platform for implementing scalable on-chip quantum information processing with continuous variables.Comment: accepted by Phys. Rev.

Strange sea asymmetry in nucleons

We evaluate the medium effects in nucleon which can induce an asymmetry of the strange sea. The short-distance effects determined by the weak interaction can give rise to $\delta m\equiv \Delta m_s-\Delta m_{\bar s}$ where $\Delta m_{s(\bar s)}$ is the medium-induced mass of strange quark by a few KeV at most, but the long-distance effects by strong interaction could be sizable.Comment: 4 pages and no figures, Talk presented at the Third Circum-Pan-Pacific Symposium on "High Energy Spin Physics", Oct. 8-13, 2001, Beijing, Chin

Associations of Perirenal Fat Thickness with Renal and Systemic Calcified Atherosclerosis.

BackgroundWe investigated associations between perirenal fat thickness and atherosclerotic calcification in six different vascular beds.MethodsUsing a community-based cohort (n=3,919), perirenal fat thickness was estimated from computed tomography scans. It was classified as Q1 (the lowest quartile) to Q4 (the highest quartile) in each sex. Calcification in the carotid arteries, coronary arteries, thoracic aorta, abdominal aorta, iliac arteries, and renal arteries was evaluated.ResultsPerirenal fat thickness was associated with older age (P<0.01) and a higher prevalence of obesity, hypertension, and dyslipidemia (P<0.01 for all). Perirenal fat thickness was independently associated with renal arterial calcification even after adjustment for age, sex, body mass index, hypertension, dyslipidemia, smoking history, and family history of heart diseases in first-degree relatives (odds ratio [OR] per quartile of perirenal fat thickness, 1.25; 95% confidence interval [CI], 1.09 to 1.44). Compared to Q1, the odds of renal arterial calcification in Q4 was about two times higher (OR, 2.05; 95% CI, 1.29 to 3.25). After adjustment for renal arterial calcification and atherosclerotic risk factors, the only other vascular bed where perirenal fat thickness showed a significant association with calcification was the abdominal aorta (OR, 1.11; 95% CI, 1.00 to 1.23; P=0.045).ConclusionPerirenal fat thickness was independently associated with vascular calcification in the renal artery and abdominal aorta

Finite-size scaling in the interfacial stiffness of rough elastic contacts

The total elastic stiffness of two contacting bodies with a microscopically rough interface has an interfacial contribution K that is entirely attributable to surface roughness. A quantitative understanding of K is important because it can dominate the total mechanical response and because it is proportional to the interfacial contributions to electrical and thermal conductivity in continuum theory. Numerical simulations of the dependence of K on the applied squeezing pressure p are presented for nominally flat elastic solids with a range of surface roughnesses. Over a wide range of p, K rises linearly with p. Sublinear power-law scaling is observed at small p, but the simulations reveal that this is a finite-size effect. We derive accurate, analytical expressions for the exponents and prefactors of this low-pressure scaling of K by extending the contact mechanics theory of Persson to systems of finite size. In agreement with our simulations, these expressions show that the onset of the low-pressure scaling regime moves to lower pressure as the system size increases.Comment: Supplementary material is available at arXiv:1210.4255, 5 pages, 3 figure

Ocular Co-morbidity in Patients with Refractive Errors in Nigeria

Purpose: To d etermine the p attern and p revalence of other ocu lar p roblems seen in p atients with refractive errors in a Nigerian teaching hosp ital. Methods: A retrosp ective hosp ital-based review of all consecu tive p atients who p resented with signs and symp toms of refractive errors at the Obafemi Awolowo University Teaching Hosp itals Comp lex between 1st Janu ary 2007 and 31 Au gu st 2007. st Patients who had a d iagnosis of refractive error and su bsequ ently had d etailed eye examination were inclu d ed in this stu d y. Data was retrieved from the p atients’ clinical record s and analyzed with SPSS version 15. Results: Ou t of 724 new p atients seen within the stu d y p eriod , 235 had refractive errors (93 males and 142 females). Patients’ ages ranged between 7 and 74 years with a mean of 30.5+/ - 4.6 years. In more than half 54%) of the p atients, associated ocu lar co-morbid ities were d ocumented . The vision-imp airing d iseases d ocumented morbid ities in 56 (44.1) p atients were cataract 26 (20.5%), glau coma 20 (15.8%), d iabetic macu lop athy 3 (2.7%), amblyop ia, corneal op acities and CMV retinitis. Non vision-imp airing d isord ersd ocumented were conju nctivitis, 49 (38.6%); p terygium 6 (4.7%), chalazion 5 (3.9%), hypertensive retinop athy 4 (3.1%), d ry eyes and ep iscleritis. Immatu re cataract was responsible for abou t 2/ 3 of cases with p oor corrected visu al acu ity d ocumented in a large p rop ortion of the p atients 26 (11.1%). Conclusion: Patients with refractive errors need d etailed ocu lar examination for early d etection of other comorbid ities which may significantly affect vision and lead to avoid able blind ness and visu al imp airment.Key words: refractive errors, ocular co-morbid ity, glau coma, visu al imp airment, blind nes

On effects of regular S=1 dilution of S=1/2 antiferromagnetic Heisenberg chains by a quantum Monte Carlo simulation

The effects of regular S=1 dilution of S=1/2 isotropic antiferromagnetic chain are investigated by the quantum Monte Carlo loop/cluster algorithm. Our numerical results show that there are two kinds of ground-state phases which alternate with the variation of $S^1=1$ concentration. When the effective spin of a unit cell is half-integer, the ground state is ferrimagnetic with gapless energy spectrum and the magnetism becomes weaker with decreasing of the $S^1$ concentration $\rho = 1/M$. While it is integer, a non-magnetic ground state with gaped spectrum emerges and the gap gradually becomes narrowed as fitted by a relation of $\Delta \approx 1.25\sqrt{\rho}$.Comment: 6 pages, 9 figure

Effective Teaching Practice Supervison: A Predictor of Teacher Trainees' Performance in Pedagogy

The quality of teachers prepared for basic education in Africa and othercontinents of the world is a consequence of the knowledge of contentacquired and the pedagogy. Effective teaching practice supervision coulddetermine the level of teacher trainees� performance in the art of teaching. The study investigated the differences in performance of teacher trainees who embarked on continuous Teaching Practice and Supervision � TP & S (of twelve weeks) and those of non-continuous teaching practice and supervision � TP & S (of six weeks in two installments). It equally examined whether there was a relationship or not in the performance of teacher trainees when they are team supervised and when they are not teamed supervised in pedagogy. Five hundred (500) teacher trainees were randomly selected assamples from two (2) colleges of education owned by Lagos StateGovernment of Nigeria. They are Adeniran Ogunsanya College of Education (AOCOED), Ijanikin and Michael Otedola College of Primary Education (MOCPED), Noforija-Epe. Their final assessment scores at the end of 2008/2009 teaching practice exercise were utilized. Using independent t-test statistic, it was found that those who embarked on continuous TP & S were able to perform significantly better than those who embarked on noncontinuous TP & S. However, using Pearson Moment Correlation Analysis (r), there was a significant relationship in the performance of teacher trainees when they were team supervised and when they were not team supervised at all. It was suggested among others that if teacher trainees should go on continuous TP & S, they would be more skilled and thus develop competence and dexterity in pedagogy since practice makes perfection. Team supervision of pedagogy was also suggested so as to curb subjectivity and biases, even as teachers are prepared for basic education.&nbsp

Case report: The obstetric patient going for non-obstetric surgery

Surgical disease during pregnancy is relatively common. Surgical intervention depends on its urgency and priority is given to the mother's health though the surgical treatment poses threat to both mother and foetus Case Summary: A 24-year-old gravida 3 Para 2+0 known asthmatic at a gestational age of 20 weeks was diagnosed of acute appendicitis. General anaesthesia was administered with rapid sequence induction with propofol, endotracheal intubation facilitated with suxamethonium, anaesthesia maintained with pancuronium and halothane. Neuromuscular block was reversed with neostigmine. Operative findings were a ruptured appendix. She had a spontaneous vagina delivery at 36 weeks. Conclusion: Anaesthetic and surgical management of non-obstetric surgery during pregnancy is a challenge especially in developing countries where there is lack of sophisticated equipment