Radio recombination lines from the largest bound atoms in space

In this paper, we report the detection of a series of radio recombination lines (RRLs) in absorption near 26 MHz arising from the largest bound carbon atoms detected in space. These atoms, which are more than a million times larger than the ground state atoms are undergoing delta transitions (n~1009, Delta n=4) in the cool tenuous medium located in the Perseus arm in front of the supernova remnant, Cassiopeia A. Theoretical estimates had shown that atoms which recombined in tenuous media are stable up to quantum levels n~1500. Our data indicates that we have detected radiation from atoms in states very close to this theoretical limit. We also report high signal-to-noise detections of alpha, beta and gamma transitions in carbon atoms arising in the same clouds. In these data, we find that the increase in line widths with quantum number (proportional to n^5) due to pressure and radiation broadening of lines is much gentler than expected from existing models which assume a power law background radiation field. This discrepancy had also been noted earlier. The model line widths had been overestimated since the turnover in radiation field of Cassiopeia A at low frequencies had been ignored. In this paper, we show that, once the spectral turnover is included in the modeling, the slower increase in line width with quantum number is naturally explained.Comment: 5 pages, 4 figures, accepted for publication in MNRA

Magnetic phenomena at and near nu =1/2 and 1/4: theory, experiment and interpretation

I show that the hamiltonian theory of Composite Fermions (CF) is capable of yielding a unified description in fair agreement with recent experiments on polarization P and relaxation rate 1/T_1 in quantum Hall states at filling nu = p/(2ps+1), at and near nu = 1/2 and 1/4, at zero and nonzero temperatures. I show how rotational invariance and two dimensionality can make the underlying interacting theory behave like a free one in a limited context.Comment: Latex 4 pages, 2 figure

Renormalization group approach to Fermi Liquid Theory

We show that the renormalization group (RG) approach to interacting fermions at one-loop order recovers Fermi liquid theory results when the forward scattering zero sound (ZS) and exchange (ZS$'$) channels are both taken into account. The Landau parameters are related to the fixed point value of the ``unphysical'' limit of the forward scattering vertex. We specify the conditions under which the results obtained at one-loop order hold at all order in a loop expansion. We also emphasize the similarities between our RG approach and the diagrammatic derivation of Fermi liquid theory.Comment: 4 pages (RevTex) + 1 postcript file, everything in a uuencoded file, uses epsf (problem with the figure in the first version

Just-likely intersections on Hilbert modular surfaces

In this paper, we prove an intersection-theoretic result pertaining to curves in certain Hilbert modular surfaces in positive characteristic. Specifically, we show that given two appropriate curves $C,D$ parameterizing abelian surfaces with real multiplication, the set of points in $(x,y) \in C\times D$ with surfaces parameterized by $x$ and $y$ isogenous to each other is Zariski dense in $C\times D$, thereby proving a case of a just-likely intersection conjecture. We also compute the change in Faltings height under appropriate $p$-power isogenies of abelian surfaces with real multiplication over characteristic $p$ global fields

Determination of gestational age: correlation between foetal biometry and transverse cerebellar diameter in women with uncomplicated pregnancy

Background: Transverse Cerebellar Diameter (TCD) serves as a reliable predictor of gestational age in foetus and is a standard against which aberrations in other foetal parameters can be compared, especially when the GA cannot be determined by the date of last menstrual period or early pregnancy scan, TCD is one foetal parameter that has remained consistently superior in predicting gestational age in both singleton and twin gestation. Aim of the study was to assess and evaluate the effectiveness of transverse cerebellar diameter by using ultrasonography for determining the gestational age of the foetus.Methods: A cross-sectional study was done in 100 uncomplicated pregnant patients between the 15th week of gestation to term referred from routine antenatal clinic in outpatient and in-patient department of Obstetrics and Gynecology department of Vinayaka Mission Krupananda Variyar medical college and hospital, Salem during study period April 2015-March 2016. TCD is obtained in the axial plane in the cerebellar view i.e. with a slight rotation of the transducer approximately 30° from the conventional thalamic plane where the biparietal diameter is measured using the cavum septi pellucidi, third ventricle and thalami as landmarks.Results: The correlation of transcerebellar diameter (TCD) with that of BPD (bi-parietal diameter) had shown a perfect positive correlation (r = 0.978) and a similar type of correlation was also seen with HC (head circumference) (r = 0.979), AC (abdominal circumference) (r = 0.966), FL (femur length) (r = 0.976) and USG GA (ultrasonogram gestational age) (r = 0.983).Conclusions: In the normally developing foetus, the TCD increases in a linear fashion with advancing gestational age. The data of this study suggest foetal TCD on ultrasound is a reliable predictive biometric parameter of gestational age

Non-trivial Infrared Structure in (2+1)-dimensional Quantum Electrodynamics

We show that the gauge-fermion interaction in multiflavour $(2+1)$-dimensional quantum electrodynamics with a finite infrared cut-off is responsible for non-fermi liquid behaviour in the infrared, in the sense of leading to the existence of a non-trivial fixed point at zero momentum, as well as to a significant slowing down of the running of the coupling at intermediate scales as compared with previous analyses on the subject. Both these features constitute deviations from fermi-liquid theory. Our discussion is based on the leading- $1/N$ resummed solution for the wave-function renormalization of the Schwinger-Dyson equations . The present work completes and confirms the expectations of an earlier work by two of the authors (I.J.R.A. and N.E.M.) on the non-trivial infrared structure of the theory.Comment: 10 pages (LaTex), 5 figures (Postscript

Studies on site specific nutrient management (SSNM) on hybrid sunflower seed production in Southern Karnataka

A field experiment was conducted at the Main Research Station, University of Agricultural Sciences, Hebbal, Bangalore, to know the effect of Site Specific Nutrient Management (SSNM) on growth (plant height (cm), Leaf area (cm2 ), leaf area index (LAI) and dry matter production (g plant1 ) and yield (capitulum diameter (cm), No. of filled seeds, 1000 seed weight (g) and seed yield (kg ha-1 ) of hybrid sunflower seed production. The study indicated that significantly higher growth parameters viz., plant height (155.4 cm), leaf area (1293.10cm-2 ), leaf area index (0.69) and total dry matter accumulation (88.16 g plant-1 ) were recorded with SSNM for 1.2 tons ha-1 + Farm Yard Manure (FYM) as compared to recommended practice (Recommended Dose of Fertilizer 62.50:75:62.50 kg NPK ha-1 ). The application of fertilizers based on SSNM for a target yield of 1.2 t ha-1 + FYM resulted in significantly higher yield and yield attributes compared to the only application of RDF + FYM. The important yield parameters recorded that were significantly higher were viz., head diameter (19.89 cm) number of filled seeds per head (353.24), seed weight per plant (19.76 g), 1000 seed weight (43.72 g), hybrid seed yield (1003 kg ha-1 )

Lowest Landau-level description of a Bose-Einstein condensate in a rapidly rotating anisotropic trap

A rapidly rotating Bose-Einstein condensate in a symmetric two-dimensional trap can be described with the lowest Landau-level set of states. In this case, the condensate wave function psi(x,y) is a Gaussian function of r^2 = x^2 + y^2, multiplied by an analytic function P(z) of the single complex variable z= x+ i y; the zeros of P(z) denote the positions of the vortices. Here, a similar description is used for a rapidly rotating anisotropic two-dimensional trap with arbitrary anisotropy (omega_x/omega_y le 1). The corresponding condensate wave function psi(x,y) has the form of a complex anisotropic Gaussian with a phase proportional to xy, multiplied by an analytic function P(zeta), where zeta is proportional to x + i beta_- y and 0 le beta_- le 1 is a real parameter that depends on the trap anisotropy and the rotation frequency. The zeros of P(zeta) again fix the locations of the vortices. Within the set of lowest Landau-level states at zero temperature, an anisotropic parabolic density profile provides an absolute minimum for the energy, with the vortex density decreasing slowly and anisotropically away from the trap center.Comment: 13 pages, 1 figur

Comparison of short-term outcomes following open and laparoscopic resections for colorectal malignancies

Background: The laparoscopic approach for colorectal cancers are still a matter of controversy. In the present study, we tried to compare the laparoscopy with open methods of colorectal resections.Methods: Retrospective study where patients diagnosed with colorectal cancer in our hospital from year 2014 January to December 2016 were taken. Total number of cases were 69 of which, the total number of right colon cases were 26. Out of twenty-six, 12 underwent open procedure and 14 underwent laparoscopic resections. Total number of left colon cancers were 09. Of these, 2 underwent open and 7 underwent laparoscopic procedure. Thirty-four (34) rectal cancers were included in the study. Of these, 12 underwent open rectal procedures and 22 underwent laparoscopic resections. Multiple parameters like duration of surgery, post-operative complications, postoperative stay, pathological T staging, lymph node yield, positive nodes, distal resection margins, circumferential radial margins were compared.Results: Operating time was significantly shorter in open procedure than laparoscopic surgery in both rectal resection and right hemicolectomies. The postoperative stay was significantly shorter in laparoscopic right hemicolectomy compared to open procedure. All other parameters like post-operative complications, T stage, lymph node yield, positive nodes, distal resection margins and CRMs were comparable in both groups. The lymph node yield was similar in upfront and post neoadjuvant carcinoma rectum cases.Conclusions: Laparoscopic colorectal resections have similar rates of complication, with shorter hospital stays with no compromise on oncological clearance with respect to lymph node yield, CRMs, distal resection margins compared to open procedures

Optimization and analysis of dry sliding wear behaviour of N-B4C/MOS2 unreinforced AA2219 nano hybrid composites using response surface methodology

The effect of heat treatment on nano-size B4C particle reinforced hybrid composites is discussed in this paper. For this, hybrid reinforced AA2219 composites with 2% by weight nano B4C and 2% by weight MoS2 particulates were fabricated using a two-stage stir casting process, and the specimens were heat treated to assess their influence on wear behavior. Experiments were carried out to study the wear behavior by varying important factors such as aging temperature, load, and sliding distance. Response Surface Methodology (RSM) designed by Box-Behnken was used to identify the critical variables influencing wear rate and optimize wear behavior. To comprehend the wear mechanisms involved, an analysis of the worn surface was presented. Based on the analysis, a regression equation with a predictability of 97.2% was developed for the response to obtain the optimum wear rate. The following order effectively captures the relative importance of the various factors determining the alloy's wear resistance: sliding distance, load, and aging temperature. When compared to load and sliding distance, heat treatments via artificial aging in the temperature range of 200-240 °C have no significant effect on the wear resistance of hybrid AA2219 composites reinforced with n-B4C and MoS2 particulates. However, when a temperature range of 200-240 °C is considered, composites exhibit better wear resistance at the aging temperature of 240 °C with ice quenching