Electronic properties of curved graphene sheets

A model is proposed to study the electronic structure of slightly curved graphene sheets with an arbitrary number of pentagon-heptagon pairs and Stone-Wales defects based on a cosmological analogy. The disorder induced by curvature produces characteristic patterns in the local density of states that can be observed in scanning tunnel and transmission electron microscopy.Comment: Corrected versio

Bacillus thuringiensis production using cassava liquid waste (manipueira) as a fermentation substrate.

In developing countries the search for inexpensive substrates to grow useful microorganisms is a desirable way to get new and safe products to protect man against insect pest losses. Bacillus thuringiensis is an entomopathogenic bacteria, which by fermentation produces endo- or exotoxins to be used against Lepidoptera or Diptera, resp. These are insect pests of economic importance in developing countries, mainly in Brazil, where 60% losses in agriculture are caused by this type of pest. Our research group has been working with B. thuringiensis since 1970; and many papers have been published on the processes, culture media composition and available substrates, culture and operational conditions, equipment and so on. Many residues and waste waters were tried forthe fermentation culture medium. This paper reports the possibility of using manipueira, a residual waste water from cassava processing as a substrate to produce B. thuringiensis by fermentation. The culture medium was composed of 75% manipueira & 25% water. Operational conditions considered agitation and aeration rate, as well as initial pH and optimum growing temperature. Microbial growth and sporulation behavior were accomplished by optical density determination, pH variation and sugar consumption. Results are promising

New diseases caused by virus, fungi and also a bacterium on rubber from Brazil and their impact on international quarantine.

More recently, leaf diseases attributable to virus, other fungi and possibly a bacterium were well recorded as a new disase of the rubber tree. In the state of Amazonas, symptoms of a systemic infection caused by virus (being identified), typified by leaf mosaic, little leaf, malformation and tree stunt were confirmed in clonal nurseries and field plantings in several clones at CNPSD. In tests, the symptoms of virus appeared more distinct at temperatures below 22oC. The new fungal leaf pathogens discovered in the nurseries and fields are Corynespora cassiicola, Periconia manihoticola (previously of minor importance), and an Ascomycete (Dothideaceae) in association with Phyllachora huberi yet to be identified. Also discovered were leaf symptoms in the form of tiny lesions, followed by premature leaf yellowing and fall, suggestive of a bacterial infection. These were reproduced in artificial inoculation with a culture of the bacterium repeatedly isolated from fields of clones Fx 3864, PFB 5, IAN 873 and PA 31. Relating these potentially dangerous new diseases to the welll-being of the rubber industry worldwide, international quarantine measures adopted today against Microcyclus ulei alone must now be reviewed. These should include additional measures for the inspection, identification and preventive pre and postquarantine treatment against the virus, bacterium and hitherto unknown fungi

Como aumentar a fertilidade do seu rebanho ovino e reduzir a mortalidade de cordeiros.

Com o aumento do rebanho tipo carne nas últimas décadas, a fertilidade das ovelhas tornou-se um aspecto ainda mais importante no desempenho econômico da produção ovina.bitstream/item/63675/1/CT-54-2006.pd

Cuidados com cordeiros hipotérmicos.

A mortalidade perinatal de cordeiros ainda é um dos grandes gargalos na produção ovina em condições extensivas de criação. Alguns estudos apontam o complexo inanição-exposição (inabilidade de mamar acompanhada de frio e/ou chuva) como responsável por 40 a 80% das perdas de cordeiros antes da assinalação.bitstream/item/67091/1/CR-33-circular-tecnica-cuidados-com-cordeiros-hipotermicos.pd

Introgressão assistida por diagnóstico molecular da mutação Booroola em rebanhos comerciais das raças Texel e Corriedale.

A alta prolificidade das ovelhas Booroola é causada por uma mutação que ocorreu naturalmente no gene do receptor para proteínas morfogenéticas de osso tipo1 B (BMPR1B). A partir de 2001 o desenvolvimento de testes genéticos possibilitou o diagnóstico desta mutação através de PCR-RFLP

Alternativa hormonal para o preparo de rufiões ovinos.

Rufiões são utilizados na implementação de várias biotécnicas reprodutivas em ovinos, como por exemplo, para detecção de cios na inseminação artificial, indução de ovulação fora da estação reprodutiva (efeito macho) e determinação da eficácia do acasalamento, pela taxa de não retorno ao cio, ao final da tempo.bitstream/item/63500/1/CO56-2006.pd

O uso da avaliação da condição corporal visando máxima eficiência produtiva dos ovinos.

A avaliação subjetiva do nível nutricional dos ovinos pode ser feita de forma bastante simples através do uso de escores da composição corporal, denominado de avaliação da condição corporal (CC).bitstream/item/55774/1/CT-57-2006.pd