420 research outputs found
Learn-by-doing and Carbon Dioxide Abatement [Revised March 2002]
There are inherent difficulties in solving LBD(learn-by-doing) models. Basic to such models is the idea that the accumulation of experience leads to a lowering of costs.
This paper is intended to explore some of the algorithmic issues in LBD modeling for carbon dioxide abatement. When using a standard algorithm for nonlinear programming, there is no guarantee that a local LBD optimum will also be a global optimum. Fortunately, despite the absence of guarantees, there is a good chance that one of the standard algorithms will produce a global optimum for models of this type. Moreover, there is a new procedure named BARON. In the case of small models, a global optimum can be recognized and guaranteed through BARON.
Eventually, it should be possible for BARON or a similar approach to be extended top large-scale LBD models for climate change. Meanwhile, in order to check for local optima, the most practical course is to apply several different nonlinear programming algorithms - and several different starting solutions with each of them
Papillomas And Carcinomas Of The Choroid Plexus: Histological And Immunohistochemical Studies And Comparison With Normal Fetal Choroid Plexus
Background: Choroid plexus tumors are rare. Results on immunohistochemical features are scanty and controversial even regarding normal plexus. Method: Thirteen cases of choroid plexus tumors and five samples of normal fetal choroid plexus were submitted to immunohistochemical study using a panel of epithelial, neuronal and stromal markers. Results/Conclusions: Relevant histological findings were presence of clear cells in 3/5 papillomas (PP) and 7/8 carcinomas (CA) and all 5 fetal plexuses; rhabdoid cells, desmoplasia and vascular proliferation were found respectively in 3, 4 and 5 cases out of 6 poorly differentiated CA and were absent in PP and well differentiated CA. Pancytokeratin AE1/AE3 was strongly positive in all 13 cases, even in the undifferentiated component of poorly differentiated CA, where reactivity was focal in 3 and diffuse in 3 cases. Low molecular weight cytokeratin (35βH11) was not expressed in any of the 8 CA, but was present in all 5 PP. In 4 of 6 poorly differentiated CA there was reactivity for smooth muscle actin (1A4) in 10 to 30% of the cells. This was true also for one case lacking rhabdoid cells. Laminin was undetectable in all 6 cases of poorly differentiated CA but was present in 4 PP and 2 well differentiated CA. All 5 fetal plexuses expressed GFAP.623 A600607Pianetti, G., Fonseca, L.F., Tumores do plexo coróideo (1998) Arq Neuropsiquiatr, 56, pp. 223-231Pencalet, P., Sainte-Rose, C., Lellouch-Tubiana, A., Papillomas and carcinomas of the choroid plexus in children (1998) J Neurosurg, 88, pp. 521-528Lynch, J.C., Moraes, G.P., Duarte, F., Xantogranuloma do plexo coróide (1988) Arq Neuropsiquiatr, 46, pp. 191-194Aguiar, M.F.M., Cavalcanti, M., Barbosa, H., Vilela, S.L., Mendonça, J.L., Horta, E., Síndrome de Aicardi e papiloma do plexo coróide: Uma associação rara (1996) Arq Neuropsiquiatr, 54, pp. 313-317Filho, P.G., Fonseca, L.F., Suva, M.C., Choroid plexus papilloma and Aicardi syndrome: Case report (2002) Arq Neuropsiquiatr, 60, pp. 1008-1010Matsushima, T., Choroid plexus papillomas and human choroid plexus, a light and electron microscopic study (1983) J Neurosurg, 59, pp. 1054-1062Marrazzoni, D.R., Barbosa-Coutinho, L.M., Plexos coróides: Estudo histopatológico em diferentes faixas etärias (1986) Arq Neuropsiquiatr, 44, pp. 341-350Kasper, M., Goertchen, R., Stosiek, P., Perry, G., Karsten, U., Coexistence of cytokeratin, vimentin and neurofilament protein in human choroid plexus: An immunohistochemical study of intermediate filaments in neuroepithelial tissues (1986) Virchows Arch A, 410, pp. 173-177Miettinen, M., Clark, R., Virtanen, I., Intermediate filament proteins in choroid plexus and ependyma and their tumors (1986) Am J Pathol, 123, pp. 231-240Doglioni, C., Dell'Orto, P., Coggi, G., Iuzzolino, P., Bontempini, L., Viale, G., Choroid plexus tumors: An imunocytochemical study with particular reference to the coexpression of intermediate filament proteins (1987) Am J Pathol, 127, pp. 519-529Felix, I., Phudhichareonrat, S., Halliday, W.C., Becker, L.E., Choroid plexus tumors in children: Immunohistochemical and scanning-electron-microscopic features (1987) Pediat Neurosci, 13, pp. 263-269Gabrion, J., Peraldi, S., Faivre-Bauman, A., Characterization of ependymal cells in hypothalamic and choroidal primary cultures (1988) Neuroscience, 24, pp. 993-1007Kouno, M., Kumanishi, T., Washiyama, K., Sekiguchi, K., Saito, T., Tanaka, R., An immunohistochemical study of cytokeratin and glial fibrillary acidic protein in choroid plexus papilloma (1988) Acta Neuropathol (Berl), 75, pp. 317-320Cruz-Sanchez, F.F., Rossi, M.L., Hughes, J.T., Coakham, H.B., Figols, J., Eynaud, P.M., Choroid plexus papillomas: An immunohistological study of 16 cases (1989) Histopathology, 15, pp. 61-69Sarnat, H.B., Regional differentiation of the human fetal ependyma: Immunocytochemical markers (1992) J Neuropathol Exp Neurol, 51, pp. 58-75Rubinstein, L.J., Brucher, J.M., Focal ependymal differentiation in choroid plexus papillomas: An immunoperoxidase study (1981) Acta Neuropathol (Berl), 53, pp. 29-33Taratuto, A.L., Molina, H., Monges, J., Choroid plexus tumors in infancy and childhood: Focal ependymal differentiation. An immunoperoxidase study (1983) Acta Neuropathol (Berl), 59, pp. 304-308Mannoji, H., Becker, L.E., Ependymal and choroid plexus tumors. Cytokeratin and GFAP expression (1988) Cancer, 61, pp. 1377-1385Furness, P.N., Lowe, J., Tarrant, G.S., Subepithelial basement membrane deposition and intermediate filament coexpression in choroid plexus neoplasms and ependymomas (1990) Histopathology, 16, pp. 251-255Herbert, J., Cavallaro, T., Dwork, A.J., A marker for primary choroid plexus neoplasms (1990) Am J Pathol, 136, pp. 1317-1325Newbould, M.J., Kelsey, A.M., Arango, J.C., Ironside, J.W., Birch, J., The choroid plexus carcinomas of childhood: Histopathology, immunocytochemistry and clinicopathological correlations (1995) Histopathology, 26, pp. 137-143Rorke, L.B., Packer, R.J., Biegel, J.A., Central nervous system atypical teratoid/rhabdoid tumors of infancy and childhood (1995) J Neurooncol, 24, pp. 21-28Rorke, L.B., Packer, R.J., Biegel, J.A., Central nervous system atypical teratoid/rhabdoid tumors of infancy and childhood: Definition of an entity (1996) J Neurosurg, 85, pp. 56-65Burger, P.C., ATT of the CNS: A highly malignant tumor of infancy and childhood frequently mistaken for medulloblastoma (1998) Am J Surg Pathol, 22, pp. 1083-1092Oka, H., Scheithauer, B.W., Clinicopathological characteristics of atypical teratoid/rhabdoid tumor (1999) Neurol Med Chir (Tokyo), 39, pp. 510-518Kleihues, P., Cavenee, W.K., (2000) Tumours of Central Nervous System, Pathology & Genetics, , Lyon: WHO, IARCWyatt-Ashmead, J., Kleinschmidt-DeMasters, B., Mierau, G.W., Choroid plexus carcinomas and rhabdoid tumors: Phenotypic and genotypic overlap (2001) Pediatr Dev Pathol, 4, pp. 545-549Russell, D.S., Rubinstein, L.J., (1989) Pathology of Tumours of the Nervous System. 5. Ed., , London: ArnoldSreenan, J.J., Prayson, R.A., Gliosarcoma: A study of 13 tumors, including p53 and CD34 immunohistochemistrty (1997) Arch Pathol Lab Med, 121, pp. 129-133Gessi, M., Giangaspero, F., Pietsch, T., Atypical teratoid/rhabdoid tumors and choroid plexus tumors: When genetics "surprise" pathology (2003) Brain Pathol, 13, pp. 409-414Lopes, M.B., Rosemberg, S., Almeida, P.C., Pestana, C.B., Glial fibrillary acidic protein and cytokeratin in choroid plexus tumors: An immunohistochemical study (1989) Pathol Res Pract, 185, pp. 339-341Jay, V., Ho, M., Chan, F., Malkin, D., p53 expression in choroid plexus neoplasms: An immunohistochemical study (1996) Arch Pathol Lab Med, 120, pp. 1061-1065Carlotti Jr., C.G., Salhia, B., Weitzman, S., Evaluation of proliferative index and cell cycle protein expression in choroid plexus tumors in children (2002) Acta Neuropathol, 103, pp. 1-10Ohgaki, H., Eibl, R.H., Schwab, M., Mutations of the p53 tumor suppressor gene in neoplasms of the human nervous system (1993) Mol Carcinog, 8, pp. 74-8
Growth inhibition of bacterial isolates recovered from two types of Portuguese dry smoked sausages (chouriço)
Potassium sorbate (PS), sodium benzoate (SB) and methyl p-hydroxybenzoate (MHB) were investigated
as surface treatments for their ability to inhibit the growth of 18 isolates of spoilage and pathogenic bacteria
from two types of Portuguese dry smoked sausages (Chouric o). MHB significantly inhibited the
growth rate of 12 of the isolates (p < 0.05) whereas no effect was observed for four isolates of lactic acid
bacteria, identified as Enterococcus faecium, Pediococcus acidilactici and Lactobacillus curvatus, and two isolates
identified as Clostridium aminovalericum and Staphylococcus epidermidis. PS and SB had less influence
on the bacterial growth rates. It was concluded that MHB can be applied as surface treatment to improve
the stability and safety of the product along shelf life period in modified atmosphere packag
Deterioracão da carne de peru embalada em aerobiose e em atmosfera modificada sua relação com os teores de azoto básico volátil total
8º Encontro de Química dos Alimentos. Congresso. Beja, Portugal. 4 – 7 Março 2007Este estudo teve como objectivos a determinacão do prazo de validade de carne de peru de diferentes categorias de cor em aerobiose e atmosfera modificada e o estabelecimento de uma relacão entre a qualidade microbiológica da carne e o azoto básico volátil total (ABVT). Os peitos de carcaças de peru foram seleccionados através dos parâmetros Luminosidade (L) e pH: L≥51 e pH5,8 para cor escura. As amostras de carne fatiada (peitos de peru fatiados) provindas de diferentes dias de colheita, foram embaladas individualmente: um grupo em aerobiose e outro em atmosfera modificada (MAP) contendo a mistura de gases 50%N2 e 50%CO2. As amostras foram armazenadas no escuro em refrigeração (0±1ºC). O grupo de amostras embaladas em aerobiose foi avaliado em relação às suas características microbiológicas e foi determinado o azoto básico volátil total aos 0, 5 e 12 dias de armazenamento, prolongando-se essa avaliação para as amostras embaladas em atmosfera modificada até aos 19 e 25 dias. A carne de cor escura com 12 dias de armazenamento a 0ºC em aerobiose apresentou contagens significativamente mais elevadas de aeróbios a 30°C, psicrotróficos e ABVT do que a carne de outras categorias. O período de validade microbiológico da carne de peru fatiada embalada em MAP prolongou-se durante mais uma semana na carne de cor clara e intermédia (20 dias) do que na escura nas condições deste estudo. Valores de ABVT de 20-30 mg NH3/100 mg de carne de peru correspondem a estados avançados de deterioracão da carne, indicando-se como limite de aceitabilidade na carne de peru crua fresca valores de ABVT de 14 mg de NH3/100mg
Behavior problems and prevalence of asthma symptoms among Brazilian children.
OBJECTIVE: Asthma is the most common chronic disease in childhood and has been designated a public health problem due to the increase in its prevalence in recent decades, the amount of health service expenditure it absorbs and an absence of consensus about its etiology. The relationships among psychosocial factors and the occurrence, symptomatology, and severity of asthma have recently been considered. There is still controversy about the association between asthma and a child's mental health, since the pathways through which this relationship is established are complex and not well researched. This study aims to investigate whether behavior problems are associated with the prevalence of asthma symptoms in a large urban center in Latin America. METHODS: It is a cross-section study of 869 children between 6 and 12 years old, residents of Salvador, Brazil. The International Study of Allergy and Asthma in Childhood (ISAAC) instrument was used to evaluate prevalence of asthma symptoms. The Child Behavior Checklist (CBCL) was employed to evaluate behavioral problems. RESULTS: 19.26% (n=212) of the children presented symptoms of asthma. 35% were classified as having clinical behavioral problems. Poisson's robust regression model demonstrated a statistically significant association between the presence of behavioral problems and asthma symptoms occurrence (PR: 1.43; 95% CI: 1.10-1.85). CONCLUSION: These results suggest an association between behavioral problems and pediatric asthma, and support the inclusion of mental health care in the provision of services for asthma morbidity
Antibiotic Resistance and Virulence Factors among Enterococci Isolated from Chourico, a Traditional Portuguese Dry Fermented Sausage
Enterococci are ubiquitous microorganisms, found as part of the normal intestinal microbiota of many animals. They can be present in food products, for example, the Portuguese dry fermented sausage chourico. Twenty enterococci were isolated from chourico in two processing units; after identification and typification by conventional-molecular methods, the isolates were screened for virulence factors and antibiotic resistance. Identification allocated all enterococci to the species Enterococcus faecalis, and PCR fingerprinting demonstrated that each isolate was specific to the processing unit and chourico from which it was recovered. Regarding the screening for virulence factors, I strain produced cytolysin and 4 were gelatinase positive, but none produced lipase. The ace gene was detected in I enterococci, ebpABC and efaA(fs). in 16 isolates each, esp in 3, fsrB in 5, gelE in 7, and cylA in I. A multiresistant phenotype was observed in 8 isolates, 6 belonging to factory A. The antibiotic resistance gene ere(B) was detected in 9 enterococci, whereas the genes tet(M), aac(6')-le-aph(2 ''), and vanA were detected in 8 isolates each. As some of the E. faecalis chourico isolates present a multiresistant profile and harbor virulence and/or resistance genes, to assess further the safety of Portuguese dry sausages, a larger number of products and processing units must by analyzed
Contribuição para a caracterização nutricional de alguns produtos de salsicharia
8º Encontro de Química dos Alimentos. Congresso. Beja, Portugal 4 – 7 Março 2007O consumo de produtos de salsicharia é comum na dieta mediterrânica. No entanto, eles são tidos como alimentos de elevado valor calórico e o seu consumo tem sido associado a doenças do foro cardiovascular. A maioria dos produtos de salsicharia disponíveis no mercado, não apresenta informação nutricional, a qual seria um atributo a acrescentar na rotulagem, facilitando a escolha do consumidor, visto que nem todos apresentarão o mesmo aporte energético. Este trabalho surge como uma tentativa de caracterização nutricional de alguns produtos de salsicharia. Com esse objectivo, utilizaram-se resultados de análises físico-químicas realizadas a um total de 383 amostras (fiambre da perna, n=31; fiambre da pá, n=12; filete afiambrado, n=18; mortadela, n=18; paio York; n=18; painho, n=13; toucinho fumado, n=9; chouriço corrente, n=217; chourição, n=26; salpicão, n=7; linguiça, n=14). Estas análises, realizadas no âmbito do controlo de qualidade, foram efectuadas em produtos finais de salsicharia de diferentes indústrias, a serem colocados no mercado. O valor energético foi determinado, utilizando os coeficientes de conversão de Atwater, expressando-se os resultados em kcal e em kJ por 100 gramas da parte edível. Concluiu-se que estes produtos apresentam distintas características nutricionais; com base nos resultados obtidos, propõe-se, tentativamente, a classificação em três grupos: (1) Baixo valor calórico: ( 627 kJ/100g) que inclui produtos como o Fiambre da Perna, Fiambre da Pá e o Paio York; (2) Médio valor calórico: (entre 150 e 300 kcal/100g 627 e 1254 kJ/100g) para produtos como Paínho, Filete Afiambrado, Salpicão e Mortadela; (3) Alto valor calórico: (>300 kcal/100g 1254 kJ/100g) que caracteriza produtos como o Toucinho Fumado, Chourição, Linguiça e Chouriço Corrente
Evaluation of antibiotic susceptibility of Lactobacillus plantarum isolated from traditional Portuguese sausage products
Nowadays the use of fermentative microbiota in food products is researched in order to confer protection to the products and furnish health benefits to consumers The aim of this work was to evaluate antibiotics susceptibility of Lactobacillus plantarum isolated from fermented traditional meat products in order to select them to be used as starters or protective bacteria on fermented meat products. The susceptibility of different L. plantarum isolates (n=44) from fermented/dry/smoked meat products of three different Portuguese industries were tested by Agar disc diffusion method for Vancomycin, Quinupristin/Dalfopristin, Rifampicin, Penicillin G, Erythromycine, Tetracycline, Gentamicin, Lincomycin and Chloramphenicol. Most of the studied L plantarum isolates were susceptible for Tetracycline (75%) and Erythromycin (71%) and could be used safely as starter cultures. Those that presented resistance need to be genetically evaluated since the mechanism of resistance is probably related to mobile genetic elements carried by L plantarum
Avaliação da atividade antioxidante e citotóxico in vitro do óleo essencial de curcuma zedoaria (christm.) Roscoe / Evaluation of in vitro antioxidant and cytotoxic activity of curcuma zedoaria (christm.) Roscoe Essential oil
Curcuma zedoaria (Christm.) Roscoe é uma planta herbácea e rizomatosa da família Zingiberaceae. As folhas e os rizomas do gênero Curcuma são fontes de óleos essenciais utilizados na indústria química, farmacêutica e de alimentos devido a sua ação antioxidante. O óleo essencial de Curcuma zedoaria possui potente atividade citotóxica, antioxidante e inibe a proliferação celular de diversos tipos de cânceres. Apesar da sua importância biológica e econômica verificamos ausência na literatura de ensaios in vitro com método de difusão em culturas de Escherichia coli BW9091 e AB1157 sob a ação de agentes oxidantes (SnCl2 e H2O2) que atacam o DNA cromossômico e nucleotídeos livres e de estudos que descrevam a ação do óleo essencial com o antibiótico amoxicilina. Vale ressaltar que as cepas Escherichia coli AB1157 e BW9091 apresentam, respectivamente, todos os mecanismos de reparos funcionantes para o reparo de DNA e uma deficiência na exonuclease III (xthA-), isto é, deficiência nos sistemas envolvidos na correção de danos oxidativos do DNA por excisão de bases (BER). Já o antibiótico amoxicilina tem mobilizado a atenção e preocupação em serviços hospitalares devido ao aumento de casos de resistência microbiana. Verificou-se, neste estudo que óleo essencial de Curcuma zedoaria inibiu as cepas Escherichia coli BW9091 nas concentrações de 12 e 24 L. Contudo, a diferença na concentração foi, ligeiramente, mais perceptiva em Escherichia coli AB1157 (p<0,001) do que com a Escherichia coli BW9091 (p<0,01). É provável que a presença do gene mutante na cepa Escherichia coli BW9091 tenha promovido um aumento da resistência ao efeito inibitório do óleo essencial. Verificamos que o óleo essencial de Curcuma zedoaria nas concentrações de 24 e 12 µL apresentou potencial inibitório em ambas as cepas de Escherichia coli. Verificou-se, em Escherichia coli AB 1157, que a associação entre o óleo essencial e amoxicilina na concentração de 12 µL apresentou um halo de inibição maior do que quando administrado com o antibiótico isolado. O teste Turkey Kramer demonstrou que houve uma diferença significativa (p<0.001) entre as médias desses halos. A associação de óleo essencial com o cloreto estanoso 12 µL teve seu efeito citotóxico potencializado com ambas as cepas. Entretanto, em Escherichia coli AB 1157 o halo de inibição foi menor, demonstrando que o óleo essencial pode exercer um efeito sinérgico quando associado ao cloreto estanoso. Vale a pena ressaltar que essas diferenças foram significativas (p<0.01) tanto para a Escherichia coli AB1157 e BW9091. Já no controle positivo do peróxido de hidrogênio (H2O2) + 12 µL do óleo essencial observamos aumento na ação oxidativa na cepa AB1157. Portanto, concluímos que o óleo essencial tem potencial farmacológico como princípio ativo natural; exerceu atividades antioxidante e antimicrobiana sobre as cepas de Escherichia coli testadas e potencializou o efeito inibitório quando associado ao antibiótico amoxicilina
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