158 research outputs found
Feasibility Study on the Use of the Internet for Traffic of Unclassified Data
This research compares two possible networking methods for connecting all Brazilian Air Force Materiel Command units responsible for support and operation of Brazilian Air Force\u27s weapons systems. The network includes the use of dedicated X.25 links, and the use of a virtual Private Network using the Internet (TCP/IP) as the medium of transmission. The Brazilian Air Force Materiel Command, responsible to support operating units over a very large sparse territory, lacks an efficient media of computer communications, which makes it difficult to control the supply chain channels of materiel present in each unit, depots, and warehouses. We studied the network infrastructure necessary to solve this problem, and proposed two different scenarios. One uses the current level of technology based on dedicated X.25 environment, and the other uses the incipient Virtual Private Networking technology and the Internet as the communication medium. The results suggest that the Brazilian Air Force could be able to use the Internet and VPN technology in a moderated secure environment (C2 Level), and could save more than $100,000 per month in comparison to the implementation of the same level of networking using the present X.25 model. This study concludes that the BAF may benefit from the use of the VPN model in a secure and less costly environment, while maintaining the necessary flexibility and high performance to operate in the newly paradigm of distributed environments. Other implications for the Brazilian Air Force regarding Information Warfare issues and recommendations for further study are discussed
Desempenho do consórcio entre repolho e rabanete com pré-cultivo de crotalária, sob manejo orgânico.
Foram conduzidos dois experimentos no Sistema Integrado de
Produção Agroecológica, em Seropédica, (RJ), durante dois anos consecutivos. O objetivo foi avaliar o desempenho do consórcio entre as culturas de repolho e rabanete com pré-cultivo de crotalária, sob manejo orgânico. Usou-se delineamento experimental de blocos ao acaso com sete repetições, em parcelas subdivididas, representando um fatorial 2 x 3, sendo o primeiro fator o pré-cultivo, com Crotalaria juncea e pousio (vegetação espontânea); e o segundo fator o sistema de cultivo (consórcio entre repolho e rabanete e os respectivos monocultivos). Não houve diferença significativa no tocante à produtividade do repolho ou rabanete, entre C. juncea e pousio, independentemente do tipo de manejo (monocultivos ou consórcio). O desenvolvimento do repolho não foi influenciado pela presença do rabanete, no consórcio entre essas espécies sob cultivo orgânico. O rabanete sob consórcio apresentou redução no diâmetro médio, massa
média e produtividade de raízes, sem, contudo,desqualificar o padrão comercial das raízes colhidas. Considerando a média dos dois anos experimentais, o IEA atingiu 1,59, o que indicou a viabilidade do consórcio, otimizando práticas culturais, incluindo adubação,capina e irrigação
Platinum and palladium complexes with 2,4-Dinitrophenylhydrazine: synthesis and cytotoxic activity
New complexes of platinum and palladium were isolated with 2,4-dinitrophenylhydrazine (2,4-DNPH). These complexes were characterized and the results shown that the ligand is coordinated to platinum or palladium by the basic nitrogen of NH2 group and have the general structure cis-[M(2,4- DNPH)2Cl2 ].H2O where M = Pt or Pd. The thermal stability of the complexes was followed in the temperature range 25-850 ºC. The antitumor activity of the synthesized compounds has been studied and the compound cis-[Pt(2,4-DNPH)2Cl2 ], was found to display cytotoxicity (IC50 = 4.6 μmol/L) against K562 tumoral cell line. This work is the first to describe the cytotoxic activity of complexes containing 2,4-dinitrophenylhydrazineColegio de Farmacéuticos de la Provincia de Buenos Aire
Karyotype analysis in Bignonieae (Bignoniaceae): chromosome numbers and heterochromatin
Excited States of Proton-bound DNA/RNA Base Homo-dimers: Pyrimidines
We are presenting the electronic photo fragment spectra of the protonated
pyrimidine DNA bases homo-dimers. Only the thymine dimer exhibits a well
structured vibrational progression, while protonated monomer shows broad
vibrational bands. This shows that proton bonding can block some non radiative
processes present in the monomer.Comment: We acknowledge the use of the computing facility cluster GMPCS of the
LUMAT federation (FR LUMAT 2764
Gender Dimorphism in Skeletal Muscle Leptin Receptors, Serum Leptin and Insulin Sensitivity
To determine if there is a gender dimorphism in the expression of leptin receptors (OB-R170, OB-R128 and OB-R98) and the protein suppressor of cytokine signaling 3 (SOCS3) in human skeletal muscle, the protein expression of OB-R, perilipin A, SOCS3 and alpha-tubulin was assessed by Western blot in muscle biopsies obtained from the m. vastus lateralis in thirty-four men (age = 27.1±6.8 yr) and thirty-three women (age = 26.7±6.7 yr). Basal serum insulin concentration and HOMA were similar in both genders. Serum leptin concentration was 3.4 times higher in women compared to men (P<0.05) and this difference remained significant after accounting for the differences in percentage of body fat or soluble leptin receptor. OB-R protein was 41% (OB-R170, P<0.05) and 163% (OB-R128, P<0.05) greater in women than men. There was no relationship between OB-R expression and the serum concentrations of leptin or 17β-estradiol. In men, muscle OB-R128 protein was inversely related to serum free testosterone. In women, OB-R98 and OB-R128 were inversely related to total serum testosterone concentration, and OB-R128 to serum free testosterone concentration. SOCS3 protein expression was similar in men and women and was not related to OB-R. In women, there was an inverse relationship between the logarithm of free testosterone and SCOS3 protein content in skeletal muscle (r = −0.46, P<0.05). In summary, there is a gender dimorphism in skeletal muscle leptin receptors expression, which can be partly explained by the influence of testosterone. SOCS3 expression in skeletal muscle is not up-regulated in women, despite very high serum leptin concentrations compared to men. The circulating form of the leptin receptor can not be used as a surrogate measure of the amount of leptin receptors expressed in skeletal muscles
Prevalence of abnormal electrocardiographic findings in a Brazilian cohort of young football players : b-pro foot ECG pilot study
Physiological electrocardiographic findings in a Brazilian cohort of young football players : b-pro foot ecg pilot study
Time course and mechanisms of left ventricular systolic and diastolic dysfunction in monocrotaline-induced pulmonary hypertension
Although pulmonary hypertension (PH) selectively overloads the right ventricle (RV), neuroendocrine activation and intrinsic myocardial dysfunction have been described in the left ventricle (LV). In order to establish the timing of LV dysfunction development in PH and to clarify underlying molecular changes, Wistar rats were studied 4 and 6 weeks after subcutaneous injection of monocrotaline (MCT) 60 mg/kg (MCT-4, n = 11; MCT-6, n = 11) or vehicle (Ctrl-4, n = 11; Ctrl-6, n = 11). Acute single beat stepwise increases of systolic pressure were performed from baseline to isovolumetric (LVPiso). This hemodynamic stress was used to detect early changes in LV performance. Neurohumoral activation was evaluated by measuring angiotensin-converting enzyme (ACE) and endothelin-1 (ET-1) LV mRNA levels. Cardiomyocyte apoptosis was evaluated by TUNEL assay. Extracellular matrix composition was evaluated by tenascin-C mRNA levels and interstitial collagen content. Myosin heavy chain (MHC) composition of the LV was studied by protein quantification. MCT treatment increased RV pressures and RV/LV weight ratio, without changing LV end-diastolic pressures or dimensions. Baseline LV dysfunction were present only in MCT-6 rats. Afterload elevations prolonged tau and upward-shifted end-diastolic pressure dimension relations in MCT-4 and even more in MCT-6. MHC-isoform switch, ACE upregulation and cardiomyocyte apoptosis were present in both MCT groups. Rats with severe PH develop LV dysfunction associated with ET-1 and tenascin-C overexpression. Diastolic dysfunction, however, could be elicited at earlier stages in response to hemodynamic stress, when only LV molecular changes, such as MHC isoform switch, ACE upregulation, and myocardial apoptosis were present.Supported by Portuguese grants from FCT
(POCI/SAU-FCF/60803/2004 and POCI/SAU-MMO/61547/2004)
through Cardiovascular R&D Unit (FCT No. 51/94)
Characterization of macrofauna associated with articulated calcareous algae (Corallinaceae, rhodophyta) occurring in a hydrodynamic gradient on the espírito santo state coast, brazil
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