Comparative analysis of 18S rRNA genes from Myxobolus aeglefini Auerbach, 1906 isolated from cod (Gadus morhua), Plaice (Pleuronectes platessa) and dab (Limanda limanda), using PCR-RFLP

The myxosporean parasite Myxobolus aeglefini is a marine species, which can be found in the cartilage of mainly gadid fish species. The parasite has, however, been recorded in the flatfish plaice (Pleuronectes platessa) and dab (Limanda limanda). It is not clear if isolates from unrelated hosts represent the same species. Therefore a molecular study was conducted to reveal differences at the DNA level between these isolates. PCR was successfully conducted on three different isolates of Myxobolus aeglefini sampled from cod (Gadus morhua), plaice and dab respectively, using 18S rDNA as template. A PCR product of approx. 1600 base pairs was obtained and RFLP (Restriction Fragment Length Polymerase) was conducted on the fragment with the restriction enzymes Hinf I, Msp I and Hae III. No differences between the isolates were found, suggesting that the three isolates represent the same species

Intrinsic quadrupole moment of the nucleon

We address the question of the intrinsic quadrupole moment Q_0 of the nucleon in various models. All models give a positive intrinsic quadrupole moment for the proton. This corresponds to a prolate deformation. We also calculate the intrinsic quadrupole moment of the Delta(1232). All our models lead to a negative intrinsic quadrupole moment of the Delta corresponding to an oblate deformation.Comment: 17 pages, 5 figure

Pionic Decay of a Possible d'-Dibaryon

The pionic decay of a possible d'-dibaryon in the process d' --> pi + N + N is studied in the microscopic quark shell model and with a single-quark transition operator describing the transition q --> pi + q'. For the d' with quantum numbers J^P=0^-, T=0, we employ a six-quark shell-model wave function with a spatial s^5p [51]_X-configuration with N=1 harmonic oscillator quanta. It is shown that the pionic decay width depends strongly on the mass and size of the d'. In the case that the calculated d' mass is close to the experimental one a small pionic decay width of 0.04 MeV is obtained. This is an order of magnitude smaller than the experimentally suggested value of 0.5 MeV. Two possibilities to improve the calculated width are suggested. The effect of the nonstatic correction term in the transition operator and the influence of the form factor at the decay vertex on the decay width are also discussed.Comment: Latex, 15 pages, 1 postscript figure, accepted for publication in Nucl. Phys.

A simple clinical formula for predicting fetal weight in labour at term – derivation and validation

Objectives. To derive and validate a simple formula for birth weight based on symphysis-fundal height (SFH) measurement during labour, and to determine a useful SFH cut-off value for prediction of birth weight .4 000 g.Methods. In a derivation study, SFH was measured in womenat term in the active phase of labour. A simplified formula for birth weight was derived from a regression equation. The best cut-off SFH measurement was obtained for prediction of birth weight .4 000 g. After this, a similar study was done to validate these findings.Results. In the derivation study (N=504), birth weight was predicted by the equation: birth weight in g=301+78 (SFH in cm). This was transformed to the simplified formula: birth weight in g=100 ([SFH in cm].5). Using this formula for the data set, 68.1% of birth weight estimates were correct to within 10% of the birth weight. For prediction of birth weight .4 000 g, an SFH measurement of 40 cm had a sensitivity of 82% and a specificity of 80%. In the validation study (N=294), the derived simplified formula gave 65.0% of estimatescorrect to within 10% of the birth weight. The predictive values of the 40 cm SFH cut-off were similar to those in the derivation study.Conclusion. The derived simplified formula was validated inthe second study. The formula may be useful for intrapartumuse in term pregnancies. A cut-off SFH measurement of 40 cmmay identify labours at risk for cephalopelvic disproportionor shoulder dystocia

Analysis of the total 12C(α,γ)16O cross section based on available angular distributions and other primary data

Because a knowledge of the 12C/16O ratio is crucial to the understanding of the later evolution of massive stars, new R- and K-matrix fits have been completed using the available angular distribution data from radiative α capture and elastic α scattering on 12C. Estimates of the total 12C(α,γ)16O rate at stellar energies are reported. In contrast with previous work, the analyses generally involve R- and K-matrix fits directly to the primary data, i.e., the energy- and angle-dependent differential yields, with all relevant partial waves fitted simultaneously (referred to here as surface fits). It is shown that, while the E1 part of the reaction is well constrained by a recent experiment on the β-delayed α-particle decay of 16N, only upper limits can be placed on the E2 ground state cross section factor which we take conservatively as SE2(300)<140 keV b. Simulations were then carried out to explore what kind of new data could lead to better restrictions on SE2(300). We find that improved elastic scattering data may be the best short-term candidate for such restrictions while significantly improving S(300) with new radiative capture data may require a longer-term effort. Theoretical models and estimates from α-transfer reactions for the E2 part of 12C(α,γ)16O are then discussed for comparison with the R- and K-matrix fits of the present work

Deriving Bounds on the Size of Spatial Areas

Many application domains such as surveillance, environmental monitoring or sensor-data processing need upper and lower bounds on areas that are covered by a certain feature. For example, a smart-city infrastructure might need bounds on the size of an area polluted with fine-dust, to re-route combustion-engine traffic. Obtaining such bounds is challenging, because in almost any real-world application, information about the region of interest is incomplete, e.g., the database of sensor data contains only a limited number of samples. Existing approaches cannot provide upper and lower bounds or depend on restrictive assumptions, e.g., the area must be convex. Our approach in turn is based on the natural assumption that it is possible to specify a minimal diameter for the feature in question. Given this assumption, we formally derive bounds on the area size, and we provide algorithms that compute these bounds from a database of sensor data, based on geometrical considerations. We evaluate our algorithms both with a real-world case study and with synthetic data

Baryon Charge Radii and Quadrupole Moments in the 1/N_c Expansion: The 3-Flavor Case

We develop a straightforward method to compute charge radii and quadrupole moments for baryons both with and without strangeness, when the number of QCD color charges is N_c. The minimal assumption of the single-photon exchange ansatz implies that only two operators are required to describe these baryon observables. Our results are presented so that SU(3) flavor and isospin symmetry breaking can be introduced according to any desired specification, although we also present results obtained from two patterns suggested by the quark model with gluon exchange interactions. The method also permits to extract a number of model-independent relations; a sample is r^2_Lambda / r_n^2 = 3/(N_c+3), independent of SU(3) symmetry breaking.Comment: 30 pages, no figures, REVTeX

Legal termination of pregnancy among teenagers and older women in Soweto, 1999-2001

Background. Legal termination of pregnancy (TOP) was introduced in South Africa in 1996. No data are available to relate the numbers of TOPs to the total number of pregnancies in specific health regions. The level of use of TOPs by women of different age groups is not known.Objective. To determine the proportion of pregnancies that end in TOP, with special reference to maternal age, and to measure trends in use from 1999 to 2001.Setting. Greater Soweto, Orange Farm and Lenasia, a densely populated urban health region served by Chris Hani Baragwanath Hospital and comprehensive primary care reproductive health services.Methods. Two cross-sectional studies performed in 1999 and 2001, counting all pregnancies managed in state-run health services, including legal terminations, spontaneous miscarriages, ectopic pregnancies and deliveries. Results. There were 5412 pregnancies in the study period (9 weeks) in 1999, and 5316 in the study period (8 weeks) in 2001. The TOP rates decreased from 16.1% to 13.6% (P = 0.20). The TOP rates for teenagers decreased from 22.3% to 16.3% (P = 0.006), but were higher than those for older women (15.2% in 1999 and 13.2% in 2001, P = 0.006 and 0.028 respectively). TOP rates for teenagers 13- 16 years decreased from 28.0% to 23.0% (P = 0.44), and rates for older teenagers declined from 21.0% to 14.9% (P = 0.008). In 2001, 16.2% of women aged 35 and above underwent TOP, compared with 12.7% of women aged 20 - 34 years (P =0.014).Conclusion. Use of TOP services was highest in women at the extremes of reproductive age. There was a significant decline in TOP rates among older teenagers between 1999 and 2001. These data, from a comprehensive urban reproductive health service, provide a benchmark for comparison elsewhere and in the future

The d'-Dibaryon in the Nonrelativistic Quark Model

The narrow peak recently found in various pionic double charge exchange (DCX) cross sections can be explained by the assumption of a universal resonance at 2065 MeV, called d'. We calculate the mass of a six-quark system with J^P=0^-, T=0 quantum numbers employing a cluster model and a shell model basis to diagonalize the nonrelativistic quark model Hamiltonian.Comment: 7 pages, Latex, 2 figures, invited talk at 6th Int. Symp. on Mesons and Nucleons 1995, Blaubeuren, Germany, 10-14 July 1995, to be published in pi-N Newsletter