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1.
Braz. j. biol ; 83: e246322, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1285614

RESUMO

Abstract A total of 10 specimens were captured from selected sites of Bajaur Agency FATA, Pakistan using mist nets. The captured specimens were morphologically identified and various morphometric measurements were taken. The head and Body length (HB) of Pipistrellus coromondra and Pipistrellus kuhlii lepidus (n=10) was 43±0.11 mm and 45±1.1 respectively. Morphologically identified Pipistrellus kuhlii confirmed as Pipistrellus kuhlii lepidus based on 16S rRNA sequences. The DNA sequences were submitted to GenBank and accession numbers were obtained (MN 719478 and MT430902). The available 16S rRNA gene sequences of Pipistrellus coromondra and Pipistrellus kuhlii lepidus were retrieved from NCBI and incorporated in N-J tree analysis. Overall, the interspecific genetic variations among Pipistrellus coromondra and Pipistrellus kuhlii lepidus were 8% and 1% respectively. In our recommendation, a comprehensive molecular identification of bats is need of hour to report more cryptic and new species from Pakistan.


Resumo Um total de 10 espécimes foi capturado em locais selecionados da Bajaur Agency FATA, Paquistão, usando redes de neblina. Os espécimes capturados foram identificados morfologicamente e várias medidas morfométricas foram realizadas. O comprimento da cabeça e do corpo (HB) de Pipistrellus coromondra e Pipistrellus kuhlii lepidus (n = 10) foi de 43 ± 0,11 mm e 45 ± 1,1, respectivamente. Pipistrellus kuhlii identificado morfologicamente e confirmado como Pipistrellus kuhlii lepidus com base em sequências de rRNA 16S. As sequências de DNA foram submetidas ao GenBank e os números de acesso foram obtidos (MN 719478 e MT430902). As sequências do gene 16S rRNA disponíveis de Pipistrellus coromondra e Pipistrellus kuhlii lepidus foram recuperadas do NCBI e incorporadas na análise da árvore N-J. No geral, as variações genéticas interespecíficas entre Pipistrellus coromondra e Pipistrellus kuhlii lepidus foram de 8% e 1%, respectivamente. Em nossa recomendação, uma identificação molecular abrangente de morcegos precisa de uma hora para relatar mais espécies crípticas e novas do Paquistão.

2.
Braz J Biol ; 83: e246322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34431908

RESUMO

A total of 10 specimens were captured from selected sites of Bajaur Agency FATA, Pakistan using mist nets. The captured specimens were morphologically identified and various morphometric measurements were taken. The head and Body length (HB) of Pipistrellus coromondra and Pipistrellus kuhlii lepidus (n=10) was 43±0.11 mm and 45±1.1 respectively. Morphologically identified Pipistrellus kuhlii confirmed as Pipistrellus kuhlii lepidus based on 16S rRNA sequences. The DNA sequences were submitted to GenBank and accession numbers were obtained (MN 719478 and MT430902). The available 16S rRNA gene sequences of Pipistrellus coromondra and Pipistrellus kuhlii lepidus were retrieved from NCBI and incorporated in N-J tree analysis. Overall, the interspecific genetic variations among Pipistrellus coromondra and Pipistrellus kuhlii lepidus were 8% and 1% respectively. In our recommendation, a comprehensive molecular identification of bats is need of hour to report more cryptic and new species from Pakistan.


Assuntos
Quirópteros , Animais , Quirópteros/genética , Paquistão , RNA Ribossômico 16S
4.
Ir Med J ; 112(3): 896, 2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-31045335

RESUMO

Introduction Elective and emergency paediatric general surgery is performed in numerous hospitals but with differing exclusion and transfer thresholds. Recent national guidelines detail necessary surgical, anaesthetic and nursing resources for safe and efficient delivery of services. Methods A retrospective review of paediatric surgical admissions was performed from January 2015 to December 2016. Charts of prolonged admissions or readmissions were reviewed. Results There was a total of 2,079 surgical admissions. 575 (27.2%) were elective and 1504 (71.2%) were emergency admissions. Significantly more surgical procedures were performed in 2016 (n=546, 56% versus n=433, 44.2%). Laparoscopic appendicectomy was the most commonly performed procedure. Re-admission rates were lower in 2016 (n=9, 0.8% versus n=21, 2.2%). All complications were Clavien-Dindo Grade I or II. Discussion Paediatric general surgery can be safely and efficiently performed by staffed and resourced Model III hospitals.


Assuntos
Procedimentos Cirúrgicos Eletivos/estatística & dados numéricos , Tratamento de Emergência/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Pediatria/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Hospitais , Humanos , Lactente , Tempo de Internação , Masculino , Readmissão do Paciente/estatística & dados numéricos , Estudos Retrospectivos , Segurança , Fatores de Tempo
5.
Insect Mol Biol ; 28(6): 785-797, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30980445

RESUMO

Gut-expressed aphid genes, which may be more easily inhibited by RNA interference (RNAi) constructs, are attractive targets for pest control efforts involving transgenic plants. Here we show that expression of cathepsin L, which encodes a cysteine protease that functions in aphid guts, can be reduced by expression of an RNAi construct in transgenic tobacco. The effectiveness of this approach is demonstrated by up to 80% adult mortality, reduced fecundity, and delayed nymph production of Myzus persicae (green peach aphids) when cathepsin L expression was reduced by plant-mediated RNAi. Consistent with the function of cathepsin L as a gut protease, M. persicae fed on the RNAi plants had a lower protein content in their bodies and excreted more protein and/or free amino acids in their honeydew. Larvae of Coccinella septempunctata (seven-spotted ladybugs) grew more slowly on aphids having reduced cathepsin L expression, suggesting that prey insect nutritive value, and not just direct negative effects of the RNAi construct, needs to be considered when producing transgenic plants for RNAi-mediated pest control.


Assuntos
Afídeos/fisiologia , Catepsina L/genética , Besouros/fisiologia , Cadeia Alimentar , Expressão Gênica , Proteínas de Insetos/genética , Animais , Afídeos/genética , Afídeos/crescimento & desenvolvimento , Catepsina L/metabolismo , Inativação Gênica , Proteínas de Insetos/metabolismo , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Comportamento Predatório , Interferência de RNA , Tabaco/genética , Tabaco/fisiologia
6.
Acta Virol ; 63(1): 26-35, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30879310

RESUMO

Whitefly-transmitted viruses of the genus Begomovirus (the family Geminiviridae) have become a limiting factor for agricultural productivity in many warmer parts of the world. The economies of Pakistan and India have, since the early 1990s, suffered losses due to cotton leaf curl disease (CLCuD). The disease is caused by begomoviruses, the most important of which at this time is cotton leaf curl Kokhran virus strain Burewala (CLCuKoV-Bu), and a disease-specific betasatellite, cotton leaf curl Multan betasatellite (CLCuMuB). Efforts to minimize losses due to CLCuD rely mainly on the use of insecticides to kill the whitefly vector; no resistant cotton varieties are currently commercially available. The study described here has investigated RNA interference technology for its potential to yield resistance against CLCuKoV-Bu and three other begomoviruses; CLCuKoV, tomato leaf curl New Delhi virus (ToLCNDV) and Pedilanthus leaf curl virus (PeLCV). Three fragments of the virion-sense V2 gene of CLCuKoV-Bu were transformed into Nicotiana benthamiana in antisense orientation and transgenic lines expressing virus-specific short RNAs were assessed for their ability to yield resistance. Only CLCuKoV-Bu with the V2 sequence closest to the promoter was resistant. Inoculation of CLCuKoV-Bu with CLCuMuB into transgenic plants did not significantly affect the outcome, although viral DNA was detected in number of plants, suggesting that the betasatellite may impair RNAi resistance. Overall the results indicate that targeting the 5' end of V2 gene using antisense-RNA has the potential to deliver resistance against begomoviruses and that RNAi-based resistance imparts some degree of resistance to heterologous viruses. Keywords: geminivirus; begomovirus; RNAi; resistance; CLCuKoV-Burewala; CLCuMuB.


Assuntos
Begomovirus , Resistência à Doença , Tabaco , Begomovirus/genética , Begomovirus/fisiologia , DNA Viral/genética , Resistência à Doença/genética , Doenças das Plantas/genética , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas , Interferência de RNA , Tabaco/genética , Tabaco/virologia
7.
Acta Virol ; 63(1): 36-44, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30879311

RESUMO

Alphasatellites, formerly known as DNA 1, are a satellite-like components associated with begomoviruses (the family Geminiviridae) that require betasatellite for symptom induction but depend on DNA-A for systemic movement. We have converted alphasatellite into gene-silencing vector (modified alphasatellite (∆DNA 1)) by deleting its A-rich region that does not affect the replication nor the movement of the helper virus. Insertion of a transgene green florescence protein (GFP) into ∆DNA 1 resulted in the silencing g of the cognate gene in Nicotiana benthamiana. The silencing persisted for more than one and half month and was associated with the decreased level of mRNA of the target gene. This satellite-like DNA vector induced gene silencing (VIGS) promises to be applicable to other begomovirus/alphasatellite systems, thereby providing the powerful approach to gene discovery and the analysis of gene functions in malvaceous crops. Keywords: cotton; begomovirus; alphasatellite; RNAi.


Assuntos
Begomovirus , Resistência à Doença , Inativação Gênica , Tabaco , Begomovirus/genética , Begomovirus/fisiologia , DNA Satélite/genética , Resistência à Doença/genética , Vetores Genéticos/genética , Tabaco/genética , Tabaco/virologia
8.
J Contemp Dent Pract ; 20(12): 1389-1394, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381838

RESUMO

AIM: The present study was done to determine the activity of licorice root extract on Streptococcus mutans (S. mutans) in comparison to chlorhexidine and fluoride mouthwash. MATERIALS AND METHODS: In the current study, the different concentrations of aqueous and ethanolic licorice root extract were subjected to microbiological assay and zone of inhibition was determined against S. mutans by agar ditch method. Minimum inhibitory concentration (MIC) of aqueous and ethanolic solution was obtained by using broth dilution method and agar dilution method. Chlorhexidine and fluoride mouthwash were kept as a positive control in the present study. One-way ANOVA along with Tukey post hoc test were used at 5% level of significance to analyze data. RESULTS: Mean zone of inhibition of chlorhexidine mouthwash, fluoride mouthwash, aqueous and ethanolic licorice root extracts against S. mutans at 24 hours were 23 mm, 14.2 mm, 15.8 mm and 22.4 mm, respectively. Minimum inhibitory concentration of aqueous and ethanolic licorice root extract on S. mutans was 20 mg/mL and 12.5 mg/mL, respectively by both broth dilution method and agar dilution method. CONCLUSION: The antibacterial effect produced by ethanolic licorice root extract on S. mutans was comparable to chlorhexidine mouthwash while significantly higher in comparison with aqueous form and fluoride mouthwash. CLINICAL SIGNIFICANCE: The interest in the plants with antibacterial and anti-inflammatory activity has increased now days to treat various dental diseases as consequences of current problems associated with the conventional agents. Licorice root is easily available, economically feasible and culturally acceptable and may possess minimal side effects as compared to conventional means of chemicotherapeutic agents used for reduction of S. mutans in oral cavity and hence can be recommended for prevention of dental caries.


Assuntos
Cárie Dentária , Glycyrrhiza , Clorexidina , Fluoretos , Humanos , Antissépticos Bucais , Extratos Vegetais , Streptococcus mutans
9.
Int J MS Care ; 18(5): 239-247, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27803639

RESUMO

Background: Footdrop is a significant problem in multiple sclerosis, reducing the safety and efficiency of walking. Functional electrical stimulation (FES) can produce dorsiflexion, correcting footdrop. The purpose of this retrospective analysis of clinical study data was to compare the effect of external and implanted FES devices for the correction of footdrop. Methods: External FES was used for a minimum of 6 months before implantation. Walking performance was assessed using 10-m walking speed, 3-minute walking distance, the Physiological Cost Index, and health- and device-related quality of life and device-use questionnaires. Assessments were made before implantation and a mean (SD) of 128 (24) days after surgery, with additional walking speed measurements at 3 years. Results: Twenty-three people with multiple sclerosis received the STIMuSTEP implant. Both devices enabled statistically significant increases in walking speed and walking distance, with a strong trend toward a reduced Physiological Cost Index, indicating that walking required less effort (P = .07). Both devices improved device-related quality of life. Walking speed gain with FES was maintained at 3 years. Three implants failed after falls, and there was one case of neuropraxia. The implant was used more days per week and was quicker to put on each day than the external FES device. Conclusions: The STIMuSTEP implanted dropped foot stimulator is an effective long-term intervention for the correction of footdrop.

10.
Asian Pac J Cancer Prev ; 16(10): 4335-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26028095

RESUMO

BACKGROUND: Oral cancer is the third most common malignancy in Saudi Arabia, the highest incidence of which is reported from Jazan province. The objective of this study was to evaluate the association of various locally used substances, especially shamma, with oral cancer in the Jazan region of Saudi Arabia. MATERIALS AND METHODS: A hospital-based case-control study was designed and patient records were scanned for histologically confirmed oral cancer cases. Forty eight patients who were recently diagnosed with oral cancer were selected as cases. Two healthy controls were selected for each observed case and they were matched with age (+/-5 years) gender and location. Use of different forms of tobacco such as cigarettes, pipe-smoking and shamma (smokeless- tobacco) was assessed. Khat, a commonly used chewing substance in the community was also included. Descriptive analysis was first performed followed by multiple logistic regression (with and without interaction) to derive odds ratios (ORs) and 95% confidence interval (CIs). RESULTS: Mean age of the study sample (56% males and 44% females) was 65.3 years. Multinomial regression analysis revealed that shamma use increased the odds of developing oral cancer by 29 times (OR=29.3; 10.3-83.1). Cigarette (OR=6.74; 2.18-20.8) was also seen to have an effect. With the interaction model the odds ratio increased significantly for shamma users (OR=37.2; 12.3-113.2) and cigarette smokers (OR=10.5; 2.88-3.11). Khat was observed to have negative effect on the disease occurrence when used along with shamma (OR=0.01; 0.00-0.65). CONCLUSIONS: We conclude that shamma, a moist form of smokeless tobacco is a major threat for oral cancer occurrence in the Jazan region of Saudi Arabia. This study gives a direction to conduct further longitudinal studies in the region with increased sample size representing the population in order to provide more substantial evidence.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Neoplasias Bucais/epidemiologia , Fumar/efeitos adversos , Tabaco sem Fumaça/efeitos adversos , Idoso , Carcinoma de Células Escamosas/etiologia , Estudos de Casos e Controles , Catha/efeitos adversos , Feminino , Humanos , Masculino , Neoplasias Bucais/etiologia , Fatores de Risco , Arábia Saudita/epidemiologia
11.
Opt Express ; 23(1): 373-83, 2015 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-25835683

RESUMO

Utilizing low-cost, 2.2GHz modulation bandwidth, uncooled and standalone directly modulated VCSEL (DM-VCSEL)-based real-time dual-band optical OFDM (OOFDM) transmitters, aggregated 16.375Gb/s transmissions of OOFDM signals having bandwidths approximately 3.8 times higher than the VCSEL manufacturer-specified modulation bandwidths, are experimentally demonstrated, for the first time, over 200m OM2 MMF links based on intensity modulation and direct detection. The aggregated signal transmission capacities of the aforementioned links vary by just 8% for various OM2 MMFs ranging from 100m to 500m, and by just 10% over a 1GHz passband carrier frequency detuning range. Such dual-band OOFDM adaptability-induced excellent performance robustness and large passband frequency tunability can significantly relax the requirements on VCSEL modulation bandwidth for achieving specific transmission performances for cost-sensitive application scenarios such as data centers.

12.
J R Army Med Corps ; 161(2): 127-31, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25168754

RESUMO

BACKGROUND: Military training is a stressful and unusual event. It may predispose individuals towards mental health problems. The stress of military training has been shown to result in depressive symptoms that can potentially influence the combat ability of a soldier. This study aimed to determine the prevalence of depressive symptoms among recruits during military training in Northern Pakistan and analyse the associated socio-demographic factors. SUBJECTS AND METHOD: The study was carried out at the Mujahid Force Center, Bhimber, in Azad Jammu and Kashmir (AJK) in the North of Pakistan. This is one of the training institutes of the Pakistan Army. The sample population comprised of 313 adult men undergoing military training at Bhimber AJK. General Health Questionnaire 12 (GHQ-12) was used to screen for any psychiatric illness, and those with a score>4 were administered the Beck Depression Inventory (BDI) to record the presence and severity of depressive symptoms. Age, service type (general duty soldier, cook or clerk), education, level of family income, marital status, tobacco smoking, use of naswar (tobacco based substance), worrying about future and social support status were correlated with depressive symptoms to evaluate the association of these factors with depression in the study population. RESULTS: Out of 313 recruits screened with GHQ-12, 232 were found to have a score of 4 or more as an indicator of the presence of psychiatric morbidity, and had the BDI administered. Of these 232 recruits, 31.5% had no depressive symptoms, 41.4% had mild, 17.7% had moderate and 9.5% had severe depressive symptoms. With logistic regression, we found significant correlation among depressive symptoms and level of family income, worrying about future and lack of social support. CONCLUSIONS: Prevalence of depressive symptoms was high among recruits. Special attention should be paid to recruits from low socioeconomic background and those who lack social support and who worry about the future.


Assuntos
Depressão/epidemiologia , Militares/psicologia , Militares/estatística & dados numéricos , Adolescente , Adulto , Estudos Transversais , Humanos , Masculino , Paquistão/epidemiologia , Prevalência , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
13.
Opt Express ; 22(16): 19674-85, 2014 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-25321051

RESUMO

Real-time optical OFDM (OOFDM) transceivers with on-line software-controllable channel reconfigurability and transmission performance adaptability are experimentally demonstrated, for the first time, utilizing Hilbert-pair-based 32-tap digital orthogonal filters implemented in FPGAs. By making use of an 8-bit DAC/ADC operating at 2GS/s, an oversampling factor of 2 and an EML intensity modulator, the demonstrated RF conversion-free transceiver supports end-to-end real-time simultaneous adaptive transmissions, within a 1GHz signal spectrum region, of a 2.03Gb/s in-phase OOFDM channel and a 1.41Gb/s quadrature-phase OOFDM channel over a 25km SSMF IMDD system. In addition, detailed experimental explorations are also undertaken of key physical mechanisms limiting the maximum achievable transmission performance, impacts of transceiver's channel multiplexing/demultiplexing operations on the system BER performance, and the feasibility of utilizing adaptive modulation to combat impairments associated with low-complexity digital filter designs. Furthermore, experimental results indicate that the transceiver incorporating a fixed digital orthogonal filter DSP architecture can be made transparent to various signal modulation formats up to 64-QAM.

14.
Indian J Ophthalmol ; 62(1): 16-22, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24492497

RESUMO

PURPOSE: Our goal was to identify the cellular and molecular effects of 2-ethylpyridine (2-EP, a component of cigarette smoke) on human retinal pigment epithelial cells (ARPE-19) in vitro. MATERIALS AND METHODS: ARPE-19 cells were exposed to varying concentrations of 2-EP. Cell viability (CV) was measured by a trypan blue dye exclusion assay. Caspase-3/7 and caspase-9 activities were measured by fluorochrome assays. The production of reactive oxygen/nitrogen species (ROS/RNS) was detected with a 2',7'-dichlorodihydrofluorescein diacetate dye assay. The JC-1 assay was used to measure mitochondrial membrane potential (ΔΨm). Mitochondrial redox potential was measured using a RedoxSensor Red kit and mitochondria were evaluated with Mitotracker dye. RESULTS: After 2-EP exposure, ARPE-19 cells showed significantly decreased CV, increased caspase-3/7 and caspase-9 activities, elevated ROS/RNS levels, decreased ΔΨm value and decreased redox fluorescence when compared with control samples. CONCLUSIONS: These results show that 2-EP treatment induced cell death by caspase-dependent apoptosis associated with an oxidative stress and mitochondrial dysfunction. These data represent a possible mechanism by which smoking contributes to age-related macular degeneration and other retinal diseases and identify mitochondria as a target for future therapeutic interventions.


Assuntos
Degeneração Macular/metabolismo , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Piridinas/efeitos adversos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Poluição por Fumaça de Tabaco/efeitos adversos , Apoptose , Sobrevivência Celular , Células Cultivadas , Humanos , Degeneração Macular/induzido quimicamente , Degeneração Macular/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Piridinas/análise , Epitélio Pigmentado da Retina/patologia
15.
Open Ophthalmol J ; 7: 4-10, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23459241

RESUMO

Diabetic retinopathy remains the leading vascular-associated cause of blindness throughout the world. Its treatment requires a multidisciplinary interventional approach at both systemic and local levels. Current management includes laser photocoagulation, intravitreal steroids, and anti-vascular endothelial growth factor (VEGF) treatment along with systemic blood sugar control. Anti-VEGF therapies, which are less destructive and safer than laser treatments, are being explored as primary therapy for the management of vision-threatening complications of diabetic retinopathy such as diabetic macular edema (DME). This review provides comprehensive information related to VEGF and describes its role in the pathogenesis of diabetic retinopathy, and in addition, examines the mechanisms of action for different antiangiogenic agents in relation to the management of this disease. Medline (Pubmed) searches were carried out with keywords "VEGF", "diabetic retinopathy", and "diabetes" without any year limitation to review relevant manuscripts used for this article.

17.
Transgenic Res ; 21(2): 303-11, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21701953

RESUMO

RNA silencing technology has become the tool of choice for inducing resistance against viruses in plants. A significant discovery of this technology is that double-stranded RNA (dsRNA), which is diced into small interfering RNAs (siRNAs), is a potent trigger for RNA silencing. By exploiting this phenomenon in transgenic plants, it is possible to confer high level of virus resistance by specific targeting of cognate viral RNA. In order to maximize the efficiency and versatility of the vector-based siRNA approach, we have constructed a chimeric expression vector containing three partial gene sequences derived from the ORF2 gene of Potato virus X, Helper Component Protease gene of Potato virus Y and Coat protein gene of Potato leaf roll virus. Solanum tuberosum cv. Desiree and Kuroda were transformed with this chimeric gene cassette via Agrobacterium tumefaciens-mediated transformation and transgenic status was confirmed by PCR, Southern and double antibody sandwich ELISA detection. Due to simultaneous RNA silencing, as demonstrated by accumulation of specific siRNAs, the expression of partial triple-gene sequence cassette depicted 20% of the transgenic plants are immune against all three viruses. Thus, expression of a single transgene construct can effectively confer resistance to multiple viruses in transgenic plants.


Assuntos
Resistência à Doença , Engenharia Genética/métodos , RNA Interferente Pequeno/genética , RNA Viral/genética , Solanum tuberosum/virologia , Agrobacterium tumefaciens/genética , Southern Blotting , DNA de Plantas/genética , DNA de Plantas/metabolismo , Ensaio de Imunoadsorção Enzimática , Genes Virais , Doenças das Plantas/imunologia , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Plantas Geneticamente Modificadas/virologia , Plasmídeos/genética , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase , Potexvirus/genética , Potexvirus/imunologia , Potyvirus/genética , Potyvirus/imunologia , Interferência de RNA , Solanum tuberosum/genética , Solanum tuberosum/imunologia , Transformação Genética , Transgenes
18.
Virus Genes ; 44(1): 112-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21969121

RESUMO

Xanthium strumarium is a common weed that often shows symptoms typical of begomovirus infection, such as leaf curling and vein thickening. The virus complex isolated from the weed consisted of two begomoviruses along with a betasatellite and an alphasatellite. The first begomovirus was shown to be an isolate of Cotton leaf curl Burewala virus, a new recombinant begomovirus species that is associated with resistance breaking in previously resistant cotton varieties in Pakistan, whereas the second was shown to be an isolate of Tomato leaf curl Gujarat virus (ToLCGV), a begomovirus previously reported to be bipartite. However, there was no evidence for the presence of the second genomic component, DNA B, of ToLCGV in X. strumarium. The betasatellite was shown to be an isolate of Tomato yellow leaf curl Thailand betasatellite, the first time this satellite has been identified in Pakistan. The alphasatellite associated with infection of X. strumarium was shown to be a species recently identified in potato and various weeds; Potato leaf curl alphasatellite. Although each component has been identified previously, this is the first time they have been identified in a single host. These findings reinforce the hypothesis that weeds are reservoirs of crop-infecting begomoviruses that may contribute to virus diversity by virtue of harboring multiple viruses and virus associated components, which may lead to interspecific recombination and component exchange.


Assuntos
Begomovirus/isolamento & purificação , Doenças das Plantas/virologia , Plantas Daninhas/virologia , Vírus Satélites/isolamento & purificação , Xanthium/virologia , Begomovirus/classificação , Begomovirus/genética , Begomovirus/fisiologia , Dados de Sequência Molecular , Filogenia , Vírus Satélites/classificação , Vírus Satélites/genética , Vírus Satélites/fisiologia
20.
Opt Express ; 18(8): 8556-73, 2010 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-20588701

RESUMO

Detailed investigations of the transmission performance of adaptively modulated optical orthogonal frequency division multiplexed (AMOOFDM) signals converted using reflective semiconductor optical amplifiers (RSOAs) are undertaken over intensity-modulation and direct-detection (IMDD) single-mode fiber (SMF) transmission systems for WDM-PONs. The theoretical RSOA model adopted for modulating the AMOOFDM signals is experimentally verified rigorously in the aforementioned transmission systems incorporating recently developed real-time end-to-end OOFDM transceivers. Extensive performance comparisons are also made between RSOA and SOA intensity modulators. Optimum RSOA operating conditions are identified, which are independent of RSOA rear-facet reflectivity and very similar to those corresponding to SOAs. Under the identified optimum operating conditions, the RSOA and SOA intensity modulators support the identical AMOOFDM transmission performance of 30Gb/s over 60km SMFs. Under low-cost optical component-enabled practical operating conditions, RSOA intensity modulators with rear-facet reflectivity values of >0.3 outperform considerably SOA intensity modulators in transmission performance, which decreases significantly with reducing RSOA rear-facet reflectivity and optical input power. In addition, results also show that use can be made of the RSOA/SOA intensity modulation-induced negative frequency chirp to improve the AMOOFDM transmission performance in IMDD SMF systems.

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