437 research outputs found
The giant resonances in hot nuclei: linear response calculations
We calculate the isovector response function of hot nuclear matter using
various effective Skyrme interactions. For Skyrme forces with a small effective
mass the strength distribution is found to be nearly independent of
temperature, and shows little collective effects. In contrast effective forces
with an effective mass close to unity produce sizeable collective effects at
zero temperature which disappear at temperatures of a few MeV. We discuss the
relevance of these results for the saturation of the multiplicity of photons
emitted by the giant dipole resonance in hot nuclei beyond =3 MeV observed
in recent experiments.Comment: 6 pages, LaTeX file, 3 figures (not included, available on request)
(Contribution to the 3th IN2P3-Riken Symposium on Heavy Ion Collisions,
Shinrin-Koen, Saitama, Japan, October 1994
Endophytic hyphal compartmentalization is required for successful mycobiont-wheat interaction as revealed by confocal laser microscopy
Non-Peer ReviewedRoot endophytic fungi are seen as promising alternatives to replace chemical fertilizers and
pesticides in sustainable and organic agriculture systems. Fungal endophytes structure
formations play key roles in symbiotic intracellular association with plant-roots. To compare
the morphologies of Ascomycete endophytic fungi in wheat, we analyzed growth
morphologies during endophytic development of hyphae within the cortex of living vs dead
root cells. Confocal laser scanning microscopy (CLSM) was used to characterize fungal cell
morphology within lactofuchsin-stained roots. Cell form regularity Ireg and cell growth
direction Idir, indexes were used to quantify changes in fungal morphology. Endophyte fungi
in living roots had a variable Ireg and Idir values, low colonization abundance and patchy
colonization patterns, whereas the same endophyte species in dead (γ-irradiated) roots had
consistent form of cells and mostly grew parallel to the root axis. Knot, coil and vesicle
structures dominated in living roots, as putative symbiotic functional organs. Finally, an
increased hypha septation in living roots might indicate local specialization within
endophytic Ascomycota. Our results suggested that the applied method could be expanded to
other septate fungal symbionts
Isolated tuberculous arthritis of the dorsal facet joint
AbstractIntroductionSeptic arthritis of the facet joint is a severe infection. The lumbar spine is frequently involved; the dorsal one is rarely affected.Case reportWe present a case of a patient with a history of right cervicobrachial neuralgia with anorexia and asthenia without fever. Performed investigations had concluded to tuberculous arthritis of the dorsal facet joint. The tuberculous etiology is an originality of our observation since it has been reported in only one case. In the absence of histological and bacteriological proof, the diagnosis was established according to clinical, epidemiological and biological data. Treatment was based on antitubercular antibiotics.ConclusionThe tuberculous origin of septic facet joint should be considered in front of trolling and unexplained back pain, especially in endemic countries
Thermal and Mechanical Properties of Compression-Molded pMDI-Reinforced PCL/Gluten Composites
Many biopolymers and synthetic polymers composites were developed by different researchers for environmental protection and for cost reduction. One of these composites is polycaprolactone (PCL) and vital wheat gluten or wheat flour composites were prepared and compatibilized with polymeric diphenylmethane diisocyanate (pMDI) by blending and compression-molding. PCL/pMDI blend exhibited glass transition (Tg) at -67 °C (0.20 J/g/ °C) and vital gluten at 63 °C (0.45 J/g/ °C), whereas no Tg was recorded for wheat flour. Although Tg was unmistakable for either PCL or gluten, all composite exhibited one Tg, which is strong indication of interaction between PCL and the fillers. Several samples amongst the blended or compression-molded composites exhibited no Tg signifying another confirmation of interaction. The ΔH of the endothermic (melting) and the exothermic (crystallization) for PCL was decreased as the percentage of gluten or flour increased, whereas the overall ΔH was higher for all composites compared to the theoretical value. The presence of pMDI appeared to strengthen the mechanical properties of the composites by mostly interacting with the filler (gluten or flour) and not as much with PCL. The FTIR analysis ruled out covalent interaction between PCL, pMDI, or the fillers but suggested the occurrence of physical interactions. Based on the data presented here and the data published earlier, the presence of pMDI did not change the nature of interaction between PCL and gluten, but it improved the mechanical properties of the composite
Evaluation of the preoperative administration of sildenafil on operative and early postoperative outcome after mitral valve replacement in patients with pulmonary hypertension
Background: Mitral valve diseases are commonly associated with pulmonary hypertension. The aim of this study was to evaluate the effect of preoperative administration of sildenafil on the outcome after mitral valve replacement in patients with pulmonary hypertension.
Methods: This prospective randomized study was carried out on 67 patients who had a mitral valve replacement and associated high systolic pulmonary artery pressure more than 50 mmHg. Patients were randomized into three groups: group A (n= 20) received preoperative sildenafil for one week, group B (n=22) received sildenafil for one month, and group C (n= 25) did not receive sildenafil. All patients had transthoracic echocardiography preoperatively, one week and one month postoperatively.
Results: There was no difference in preoperative and operative variables among groups. Dobutamine support was required in 15 patients (60%) in group C vs. 6 patients (30%) in group A and 5 patients (22.5%) in group B (p= 0.012). Duration of mechanical ventilation was significantly longer in group C (389.2 ± 48.79 minutes) compared to group A and B (295.5 ± 17.01 and 281.4 ± 39.44 minutes, respectively, p<0.001). ICU stay was longer in group C (61.72 ± 13.69 hours) compared to groups A and B (53.55 ± 14.49 and 45.64 ± 13.43 hours, respectively, p=0001). The hospital stay was longer in group C (8.0 ± 1.80 days) compared to group A and B (6.05 ± 0.94 and 6.27 ± 1.24 days, respectively; p< 0.001). The transthoracic echocardiographic study one month after the operation showed that pulmonary artery systolic pressure significantly lower in groups A and B (28.30 ± 3.3 and 28.2 ± 4.98 mmHg, respectively) compared to group C (43.12 ± 4.99 mmHg) (p <0.001). There was no statistically significant difference between groups A and B regarding PASP after five days (p= 0.287) or one month (p= 0.939).
Conclusion: We found that preoperative administration of oral sildenafil in patients with pulmonary hypertension undergoing mitral valve replacement may reduce pulmonary hypertension postoperatively. We could not find a difference in the administration of sildenafil for either one week or one month preoperatively
Coherent amplification of classical pion fields during the cooling of droplets of quark plasma
In the framework of the linear sigma model, we study the time evolution of a
system of classical and pion fields coupled to quarks. For this
purpose we solve numerically the classical transport equation for relativistic
quarks coupled to the nonlinear Klein-Gordon equations for the meson fields. We
examine evolution starting from variety of initial conditions corresponding to
spherical droplets of hot quark matter, which might mimic the behaviour of a
quark plasma produced in high-energy nucleus-nucleus collisions. For large
droplets we find a strong amplification of the pion field that oscillates in
time. This leads to a coherent production of pions with a particular isospin
and so would have similar observable effects to a disoriented chiral condensate
which various authors have suggested might be a signal of the chiral phase
transition. The mechanism for amplification of the pion field found here does
not rely on this phase transition and is better thought of as a "pion laser"
which is driven by large oscillations of the field.Comment: 12 TeX pages + 20 postscript figures, psfig styl
The Breathing Mode in Extended Skyrme Model
We study an extended Skyrme model which includes fourth and sixth-order
terms. We explore some static properties like the -nucleon mass
splitting and investigate the Skyrmion breathing mode in the framework of the
linear response theory. We find that the monopole response function has a
pronounced peak located at 400 MeV, which we identify to the Roper
resonance . As compared to the standard one, the extended Skyrme model
provides a more accurate description of baryon properties.Comment: 12 pages of plain Latex and 3 figures (available from the authors),
preprint IPNO/TH 93-0
Dysregulated Glial Differentiation in Schizophrenia May Be Relieved by Suppression of SMAD4- and REST-Dependent Signaling
Combining Ability and Heterosis for Yield and Yield Components in Maize
Abstract: The study was conducted at two sites , University of Khartoum the experimental farm, faculty of Agriculture, Shambat and at west of Khartoum state, Elrawkeeb Dry Land Research Station, Sudan, during the summer and winter seasons of 2009 and 2010 respectively. Five inbred lines (2, 3, 6, 277, and 405) were used as lines and two inbred lines namely (66Y and 160) were used as (testers). These lines were crossed together according to line x tester technique to generate 10 F 1 -hybrids, every genotype was planted in rows with 4 m along, 70cm between rows and 25cm between plants. A line × tester method for estimation the general combining ability (GCA) of parent and specific combining ability (SCA) of their F 1 -hybrids was used. Genetic components resulting from additive and nonadditive type of gene action were also estimated. Heterosis was measured as a deviation from the midparents and better-parent. The analysis of variance for combining ability revealed that both GCA and SCA variances were highly significant for most of the studied characters indicating importance of additive as well as non-additive types of gene action in controlling these traits. GCA mean squares for inbred lines were significant (P < 0.01) for all the traits except cob length and number of kernels/row while GCA due to testers was only significant (P<0.05) for 100-kernels weight. Moreover, variances due to SCA were higher in magnitude than GCA for the yield and yield components except cob diameter, number of rows/cob, number of kernels/row and harvest index. GCA to SCA ratios were less than one for most of the traits except cob diameter, number of kernels row/cob, number of kernels/row and harvest index indicating a preponderance of additive over no additive gene action. High positive heterosis for grain yield and its components was found for more than half of the hybrids studied. Crosses involving 160×3 and 66Y×2 produced the highest heterosis. It can be concluded that these parental lines can be desirable parents for hybrids as well as for inclusion in breeding program, since they may contribute favorable alleles in the synthesis of new varietie
- …