987 resultados para DFG-Schwerpunktprogramm 1158 - Antarktisforschung


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Within the framework of the mean-field hydrodynamic model of a degenerate Fermi gas ( DFG), we study, by means of numerical methods and variational approximation ( VA), the formation of fundamental gap solitons ( FGSs) in a DFG ( or in a BCS superfluid generated by weak interaction between spin- up and spin- down fermions), which is trapped in a periodic optical- lattice ( OL) potential. An effectively one- dimensional ( 1D) con. guration is considered, assuming strong transverse confinement; in parallel, a proper 1D model of the DFG ( which amounts to the known quintic equation for the Tonks- Girardeau gas in the OL) is considered too. The FGSs found in the first two bandgaps of the OL- induced spectrum ( unless they are very close to edges of the gaps) feature a ( tightly bound) shape, being essentially confined to a single cell of the OL. In the second bandgap, we also find antisymmetric tightly bound subfundamental solitons ( SFSs), with zero at the midpoint. The SFSs are also confined to a single cell of the OL, but, unlike the FGSs, they are unstable. The predicted solitons, consisting of similar to 10(4) - 10(5) atoms, can be created by available experimental techniques in the DFG of Li-6 atoms.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O sucesso de uma boa aplicação de produtos fitossanitários depende da sinergia entre fatores como tamanho de gota, tipo de ponta, pressão, volume e composição da calda e características do alvo. Assim, o objetivo deste trabalho foi avaliar o espectro de gotas produzidas por pontas de jato plano defletor (TT 11002) e jato plano defletor com indução de ar (TTI 11002), com diferentes adjuvantes adicionados à calda de pulverização, pela técnica de difração de raio laser. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro repetições, em esquema fatorial 2 x 5, ou seja, duas pontas de aplicação (jato plano defletor e jato plano defletor com indução de ar) e cinco composições de calda (água e água mais quatro adjuvantes: fosfatidilcoline+ácido propiônico, éter poliglicólico de monilfenol, ésteres de ácidos graxos e nonil-fenol etoxilado+óxido de etileno). em ambiente controlado, avaliou-se o espectro de gotas, por meio de um analisador a laser de gotas em tempo real, na pressão de 276 kPa. O efeito dos adjuvantes no espectro de gotas mostrou-se dependente da ponta de pulverização empregada. A adição dos adjuvantes à calda não alterou o risco potencial de deriva, expresso pela porcentagem do volume em gotas com diâmetro inferior a 100 µm, porém o adjuvante fosfatidilcoline+ácido propiônico reduziu o diâmetro da mediana volumétrica das gotas produzidas pela ponta de jato plano defletor com indução de ar, em relação à avaliação feita somente com água.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

1. Adrenal ectopic tissue has been detected in the paragonadal region of normal women. In patients with congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency, the manifestation of hyperplasia of paragonadal accessory adrenal tissue has been usually reported to occur in males. Probably, this is the first report of a female with 3beta-hydroxysteroid dehydrogenase (3beta-HSD) deficiency with ectopic adrenal tissue in ovaries. However, the occurrence of hyperplasia of adrenal rests among women with classical congenital adrenal hyperplasia may not be rare, especially among patients with a late diagnosis.2. We report a woman with 3beta-HSD deficiency whose definitive diagnosis was made late at 41 years of age immediately before surgery for the removal of a uterine myoma. During surgery, exploration of the abdominal cavity revealed the presence of bilateral accessory adrenal tissue in the ovaries and in the para-aortic region. The patient had extremely high levels of ACTH (137 pmol/l), DHEA (901.0 nmol/l), DHEA-S (55.9 mumol/l), androstenedione (70.2 nmol/l), testosterone (23.0 nmol/l) and 17alpha-hydroxypregnenolone (234.4 nmol/l) suggesting 3beta-HSD deficiency.3. In view of these elevated androgen levels, with an absolute predominance of DHEA and DHEA-S, we evaluated the effect of this hormonal profile on carbohydrate tolerance and insulin response to glucose ingestion.4. The patient presented normal glucose tolerance but her insulin response was lower than that of 14 normal women (area under the curve, 3beta-HSD = 17,680 vs 50,034 pmol/l for the control group over a period of 3 h after glucose ingestion).5. These results support recent data suggesting that patients with increased serum DHEA and DHEA-S levels do not present resistance to insulin.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study examined the daily life and most important physical injuries suffered and reported by the dancers of a professional (contemporary) dance company in S (a) over tilde $o Paulo, Brazil. Through an observational, cross,sectional, retrospective procedure using a questionnaire that collected qualitative and quantitative data, we were able to gather information on 30 dancers who collaborated with the survey. We determined that the injuries considered as most important by dancers were those that prevented dance activity during some months. These injuries occurred mainly during rehearsals (which is the activity occuppying, the most time on the schedule). Articular injuries were the most frequent and mainly involved the knee and ankle. They were related to classical technique, in which most of the company's artists started their dance careers. Medical care usually was sought within 1 day, and the prescribed treatment resolved the problem, but the injury cause was not identified in all cases.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The pressure field in a high-power klystron amplifier is investigated to scale the ionic vacuum pump used to maintain the ultra high-vacuum in the device in order to increase its life-time. The investigation is conducted using an 1.3 GHz, 100 A - 240 keV high-power klystron with five reentrant coaxial cavities, assembled in a cylindrical drift tube 1.2 m long. The diffusion equation is solved to the regime molecular flow to obtain the pressure profile along the axis of the klystron drift tube. The model, solved by both analytical and numerical procedures, is able to determine the pressure values in steady-state case. This work considers the specific conductance and all important gas sources, as in the degassing of the drift tube and cavities walls, cathode, and collector. For the drift tube degassing rate equals to q(deg) = 2x10(-12) (-)mbar.L.s(-1) cm(-2) (degassing rate per unit area), to cavities q(cavity) = 3x10(-13) mbar.L.s(-1)cm(-2), to the cathode q(cathode) = 6x10(-9)_mbar.L.s(-1) and to the collector q(collector) = 6x10(-9) mbar.L.s(-1), it was found that a 10 L.s(-1) ionic vacuum pump connected in the output waveguide wall is suitable. In this case, the pressure obtained in the cathode is p(cathode) = 6.3x10(-9) mbar, in the collector p(collector) = 2.7x10(-9) mbar, and in the output waveguide p = 2.1x10(-9) mbar. Although only the steady-state case is analyzed, some aspects that may be relevant in a transient situation, for instance, when the beam hits the drift tube walls, producing a gas burst, is also commented.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background. To evaluate insulin release and insulin sensitivity in women with prior gestational diabetes mellitus (GDM) to gain a better understanding of type 2 diabetes pathogenesis.Methods. GDM women were individually matched for age, body mass index, and waist/hip ratio with those who were normal glucose tolerant in a previous pregnancy (NGT). All women presented with normal glucose tolerance. Twenty pairs were submitted to the oral glucose tolerance test (OGTT) with plasma glucose, insulin, and C-peptide determinations. of the 20 pairs, 18 participated in hyperglycemic (10.0 mmol/l) clamp experiments with frequent plasma glucose and insulin determinations, allowing us to calculate first- and second-phase insulin release and the insulin sensitivity index. GDM and NGT women were compared using Student's t-test, the Mann-Whitney U-test, Friedman's non-parametric test, and the two proportion test for independent groups.Results. GDM women showed higher glycosylated hemoglobin values; at OGTT, they showed late insulin peak with increased plasma insulin levels only during the second hour, and a similar plasma C-peptide response despite a higher plasma glucose curve; during hyperglycemic clamp procedures, they showed similar biphasic insulin release and insulin sensitivity index. Considering that a woman with previous GDM had a defect in insulin release and/or insulin sensitivity, if its magnitude was at least 25% lower than that of the matched NGT woman, 43.8% showed impairment of first-phase insulin release and 55.6% insulin resistance.Conclusions. GDM women showed some degree of glucose intolerance. It is therefore necessary to follow them for a longer time.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The numerical simulation of the mixmaster universe serves the purpose of suggesting two kinds of results. The intrinsic time evolution, during contraction, will be seen to be nonchaotic. This is a necessary feature of relativistic cosmological models undergoing this kind of motion. The mixmaster model also provides a clue on how to define chaoticity for systems described by nonautonomous sets of differential equations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Here is described a structural model for the binary complex CDK5-roscovitine. Roscovitine has been shown to potently inhibit cyclin-dependent kinases 1, 2 and 5 (CDK1, 2, and 5), and the structure of CDK2 complexed with roscovitine has been reported; however, no structural data, are available for complexes of CDK5 with inhibitors. The structural model indicates that roscovitine strongly binds to the ATP-binding pocket of CDK5 and structural comparison of the CDK2-roscovitine complex correlates the structural differences with differences in inhibition of these CDKs by this inhibitor. This structure opens the possibility of testing new inhibitor families, in addition to new substituents for the already known lead structures of adenine derivatives. (C) 2002 Elsevier B.V. (USA). All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Includes bibliography

Relevância:

10.00% 10.00%

Publicador:

Resumo:

PURPOSE: to investigate the effect of cigarette smoke exposure on body and tissue weight gain, serum parameters and milk yield during pregnancy and lactation in rats, and the impact on offspring from birth toil young adulthood. METHODS: 40 Wistar pregnant rats were randomly divided into: CG - not exposed to cigarette smoke and sacrificed at the end of pregnancy; CL - not exposed to cigarette smoke and sacrificed at the end of lactation; FG - exposed to cigarette smoke and sacrificed at the end of pregnancy; FL - exposed to cigarette smoke and sacrificed at the end of lactation. The offspring were separated by gender and divided according to their mothers' groups. Tissue weight, body weight and serum parameters were evaluated in rats and offspring. Milk yield per pup was calculated. RESULTS: body weight was decreased in FL during lactation (CL=267.0±7.2; FL=235.5±7.2 g*, *p<0.05). Adipose tissue was not detected in the CL and FL groups, and was reduced in FG compared to CG (CG=3.3±0.3; FG=2.4±0.3 g*, *p<0.05). Rats exposed to cigarette smoke had higher blood glucose levels (CG=113±17, CL=86±16, FG=177±21*, FL=178±23 mg/dL*, *p<0.05 CG versus FG e CL versus FL), CL and FL groups presented lower HDL-cholesterol with no change in total cholesterol. Finally, rats exposed to cigarette smoke had lower milk yield compared to unexposed rats (CL=6.7±0.4, FL=5.4±0.3 g*, *p<0.05). In offspring from the FG and FL groups, there was a decrease of body weight from birth to young adulthood, with no changes in gastrocnemius, liver or heart weights in any group, and adipose tissue was no detected in female offspring. There was an increase in blood glucose in offspring of both sexes from rats exposed to cigarette smoke (males: Pcg=107±10.5, Pcl=115±8.6, Pfg=148±16.8*, Pfl=172±11.2**; females: Pcg=109±27.2, Pcl=104±9.7, Pfg=134±20.0*, Pfl=126±13.3**; p<0.05 *Pcg versus Pfg and **Pcl versus Pfl). CONCLUSIONS: exposure to cigarette smoke provokes impairment of morphometric and serum parameters during pregnancy and lactation both in mothers and offspring, which is maintained during young adulthood.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In bovine females the release of prostaglandin F 2α (PGF 2α) is induced in vivo by estradiol (E 2). It is believed that E 2 stimulates the synthesis of essential proteins for the production of PGF 2α. This study aimed to evaluate the effect of E 2 in increasing the concentration of total protein and modifying the protein composition of endometrial explants from bovine females treated with E 2 at the 17 th day of estrous cycle. Crossbred heifers were treated at 17 th day of estrous cycle intravenously with 0 mg (Control Group; n = 6) or 3 mg of E 2 (E 2 Group; n = 6) and killed two hours after. Endometrial explants were isolated, subjected to extraction of total protein, quantified and were analyzed by onedimensional electrophoresis on polyacrylamide gel 10% SDS-PAGE. The concentration of total protein did not differ between groups, 6296.10 + 439.90 μg/mL for the Control Group and 8426.56 + 1156.00 μg/mL for E 2 Group (p = 0.1158). There was no significant difference (p > 0.05) in the protein profile of endometrial explants in gels stained with Coomasie Blue. In gels stained with Silver Nitrate it was verified in E 2 Group greater relative percentage of the bands referring to the molecular weight of 75 to 76 kDa (8.40% vs. 4.89% in E 2 Group and Control respectively; p < 0.05) and 108 to 110 Kda (6.85% vs. 3.84% in E 2 Group and Control respectively, p < 0.05). It was observed in E 2 Group lower relative percentage of the band referring to the molecular weight of 90 kDa (5.78% vs. 9.83% in E 2 Group and control respectively; p < 0.05). We concluded that the E 2 does not increase the protein concentration in the endometrium, however, it modifies the proteinic composition in the endometrial explants, indicating that E 2 alters the expression of specific proteins.