2,537 research outputs found
A Study of a-Si:H Absorption Edge Using Dunstan’s Model
تم استخدام نموذج الامتصاص البصري في أشباه الموصلات غير المتبلورة المنسوب Dunstan لتحليل بعض بيانات للامتصاص البصري لـلسيليكون العشوائي المهدرج. يقدم هذا النموذج اضطرابًا في امتصاص حزمه-الى حزمه من خلال التوزيع الأسي الخطي لفجوة الطاقة الموضعيه، والذي يمكن أن يفسر كلا من منطقتيUrbach وTauc من حافه الامتصاص البصري. مقارنة بالنماذج الأخرى ذات الأسس المماثلة، مثل نموذجيO’LearyوGuerra، فهو أبسط في الشكل الرياضي وله معنى فيزيائي مباشر. نموذج دونستان نجح في تفسير بيانات الامتصاص البصري ل Jackson et alو Maurer et al، تم استخراج معلمات فيزيائية مهمة خاصة فجوه الطاقه المتعلقه بأنتقالات حزمه-الى حزمه والتي هي فجوة الطاقة في حالة عدم وجود اللانتظام ، والتي يمكن تفسيرها على أنها فجوة التحركيه للماده.The optical absorption data of Hydrogenated Amorphous Silicon was analyzed using a Dunstan model of optical absorption in amorphous semiconductors. This model introduces disorder into the band-band absorption through a linear exponential distribution of local energy gaps, and it accounts for both the Urbach and Tauc regions of the optical absorption edge.Compared to other models of similar bases, such as the O’Leary and Guerra models, it is simpler to understand mathematically and has a physical meaning. The optical absorption data of Jackson et al and Maurer et al were successfully interpreted using Dunstan’s model. Useful physical parameters are extracted especially the band to the band energy gap , which is the energy gap in the absence of disorder, that can be interpreted as the mobility gap of the material
Caracterização molecular dos isolados 344 e 1644 de Bacillus thuringiensis (Berliner), eficazes no controle da lagarta-do-cartucho Spodoptera frugiperda (J.E. Smith).
xbitstream/item/37353/1/bol-32.pd
Molecular characterization of the Bacillus thuringiensis (BERLINER) strains 344 and 1644, efficient against fall armyworm Spodoptera frugiperda (J. E. SMITH).
Bacillus thuringiensis (Berliner) strains 344 and 1644 belonging to the CNPMS/Embrapa (Maize and Sorghum National Research Center) Microorganism Bank, located in Sete Lagoas, MG, showed to be highly efficient in controlling fall armyworm, Spodotpera frugiperda (J.E. Smith). Strains 344 and 1644 were isolated from soil samples originated from Iguassu Falls and Rolândia, respectively, Paraná State, Brazil. While strain 344 harbors cry1Ab, cry1B, cry1E and cry1Fb genes, strain 1644 showed cry1B, cry1C, and cry1D and cry1Fb genes. The strain 344 crystal has bipyramidal shape and showed LC50 equal to 8.21 x 106 spores/mL. Strain 1644 has cuboid crystal and showed LC50 equal to 2.07 x 106 spores/mL. Comparative analysis of protein profile, plasmid and amplification with primers ERIC allowed the differentiation of the evaluated strains
Nearshore marine ecology at Hutchinson Island, Florida: 1971-1974. VI. plankton dynamics, 1971-1973, VII. phytoplankton 1971-1973, VIII. zooplankton, 1971-1973, IX. diel plankton, 1973-1974, X. benthic algae species list
(Document has 122 pages.
Response of carrot roots to wounding stress induced by processing: changes in chemical composition and enzyme activity.
In the present work both whole carrot roots and Cenouretes® from the cultivars Esplanada and Sugar Snax 54, were stored for 17 days at 5 ± 1.5 °C under dark or light conditions and evaluated after 2, 5, 8, 11, 14 and 17 days of storage
Monitoring the impact of Bt maize events on the rhizosphere microbial communities cultivated in Brazil.
PENERAPAN TEKNOLOGI PENGOLAHAN MANISAN BUAH PADA KELOMPOK IBU-IBU WKRI DI KELURAHAN TAAS KECAMATAN TIKALA KOTA MANADO
Manisan adalah salah satu jenis makanan ringan dari buah-buahan dan sayuran yang diolah menggunakan gula pasir. Produk manisan buah sangat disukai oleh masyarakat karena rasanya yang manis bercampur asam dengan rasa khas buah. Teknologi pengolahan manisan buah merupakan salah satu bentuk usaha yang diterapkan selain untuk pengawetan juga untuk menambah penganekaragaman bentuk penyajian dan meningkatkan nilai tambah buah dari segi ekonomi.Tujuan Program Kemitraan Masyarakat di kelurahan Taas ini adalah untuk memberikan pengetahuan mengenai teknologi tepat guna pengolahan buah-buahan seperti tomat,nenas, dan pepaya menjadi manisan. Juga mendorong peserta dalam meningkatkan kreativitas dan meningkatkan ekonomi keluarga dengan ketrampilan yang diperoleh dari kegiatan ini. Pelaksanaan kegiatan program kemitraan masyarakat berupa penyuluhan dan pelatihan Teknologi Tepat Guna Pengolahan Manisan Buah. Pada kegiatan ini peserta diberikan materi pengetahuan tentang proses pengolahan manisan buah. Khalayak sasaran dari kegiatan ini adalah ibu-ibu WKRI kelurahan Taas kecamatan Tikala kota Manado. Target luaran yang dicapai dalam kegiatan ini yaitu: peserta mampu menerapkan teknologi pengolahan manisan buah dan mampu menghasilkan produk olahan yang bernilai ekonomi. Teknologi pengolahan manisan buah dapat dilakukan dalam skala kecil ataupun besar sehingga dapat dikembangkan menjadi wirausaha.______________________________________________________________________________Kata kunci: manisan buah, ibu-ibu kelurahan Taa
Hinge Region in DNA Packaging Terminase pUL15 of Herpes Simplex Virus: A Potential Allosteric Target for Antiviral Drugs
Approximately 80% of adults are infected with a member of the herpesviridae family. Herpesviruses establish life-long latent infections within neurons, which may reactivate into lytic infections due to stress or immune suppression. There are nine human herpesviruses (HHV) posing health concerns from benign conditions to life threatening encephalitis, including cancers associated with viral infections. The current treatment options for most HHV conditions mainly include several nucleoside and nucleotide analogs targeting viral DNA polymerase. Although these drugs help manage infections, their common mechanism of action may lead to the development of drug resistance, which is particularly devastating in immunocompromised patients. Therefore, new classes of drugs directed against novel targets in HHVs are necessary to alleviate this issue. We analyzed the conservation rates of all proteins in herpes simplex virus 1 (HHV-1), a representative of the HHV family and one of the most common viruses infecting the human population. Furthermore, we generated a full-length structure model of the most conserved HHV-1 protein, the DNA packaging terminase pUL15. A series of computational analyses were performed on the model to identify ATP and DNA binding sites and characterize the dynamics of the protein. Our study indicates that proteins involved in HHV-1 DNA packaging and cleavage are amongst the most conserved gene products of HHVs. Since the packaging protein pUL15 is the most conserved among all HHV-1 gene products, the virus will have a lower chance of developing resistance to small molecules targeting pUL15. A subsequent analysis of the structure of pUL15 revealed distinct ATP and DNA binding domains and the elastic network model identifies a functionally important hinge region between the two domains of pUL15. The atomic information on the active and allosteric sites in the ATP- and DNA-bound model of pUL15 presented in this study can inform the structure-based drug discovery of a new class of drugs to treat a wide range of HHVs
Análise molecular de fungos micorrízicos arbusculares em raízes de milho.
A comunidade nativa de fungos micorrízicos arbusculares (FMA), presente em amostras de raiz e de solo rizosférico de 15 genótipos de milho contrastantes para eficiência no uso de fósforo, foi avaliada pela técnica de eletroforese em gel de gradiente desnaturante (DGGE). Foram amplificados fragmentos do DNA ribossomal com primers específicos para as famílias Acaulosporaceae e Glomeraceae. Os primers para a família Glomeraceae foram eficientes em diferenciar a estrutura da população de fungos micorrízicos, indicando grande diversidade da comunidade entre os genótipos. No DGGE específico para Glomeraceae, foram observadas bandas exclusivas nas linhagens eficientes L228-3 e L3, ambas cultivadas sob baixo teor de fósforo, indicando uma associação preferencial entre os genótipos e os simbiontes, que pode resultar em melhor eficiência na aquisição de fósforo. Além disso, a presença de Glomus clarum nestas duas linhagens eficientes, cultivadas sob baixo P, indica uma possível relação dessa espécie à tolerância ao estresse de P nesse solo. Com relação à família Acaulosporaceae, a técnica de DGGE detectou pouca variação entre os genótipos cultivados em baixo P, além de menor diversidade de fungos micorrízicos dessa família colonizando as raízes de milho.bitstream/item/31677/1/bol-29.pd
Similaridade florística em duas áreas de Cerrado, localizadas no município de Parnarama, Maranhão - Brasil.
Pelo fato do Cerrado ser um dos biomas de grande importância e também um dos mais impactados pela atividade humana no Brasil, esse trabalho teve como objetivo realizar uma similaridade florística em duas áreas de Cerrado localizadas no município de Parnarama, Maranhão ? Brasil. Nas duas áreas foram locadas 41 parcelas, sendo distribuídas 24 na área I e 17 na área II, onde todos os indivíduos com CAP ? 31,4 cm (DAP ? 10 cm) foram mensurados bem como suas respectivas alturas e identificados botanicamente. Para análise da similaridade florística foi utilizado a distância euclidiana pelo método de Ward. Como resultado, as duas áreas apresentaram trechos distintos entre si, a área I apresentou maior diversidade e número de espécies, podendo ser classificada como uma área de cerradão. Já a segunda área vem se regenerando e desenvolvendo e, caso não haja nenhuma intervenção antrópica, a mesma poderá vir a se tornar um remanescente florestal secundário
- …