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31.
Muhammad Sarfraz Andrew B. Keddie Lloyd M. Dosdall 《Biocontrol Science and Technology》2005,15(8):763-789
The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most destructive cosmopolitan insect pests of brassicaceous crops. It was the first crop insect reported to be resistant to DDT and now, in many crucifer producing regions, it has shown significant resistance to almost every synthetic insecticide applied in the field. In certain parts of the world, economical production of crucifers has become almost impossible due to insecticidal control failures. Consequently, increased efforts worldwide have been undertaken to develop integrated pest management (IPM) programs, principally based on manipulation of its natural enemies. Although over 130 parasitoid species are known to attack various life stages of DBM, most control worldwide is achieved by relatively few hymenopteran species belonging to the ichneumonid genera Diadegma and Diadromus, the braconid genera Microplitis and Cotesia, and the eulophid genus Oomyzus. DBM populations native to different regions have genetic and biological differences, and specific parasitoid strains may be associated with the specific DBM strains. Therefore, accurate identification based on genetic studies of both host and parasitoid is of crucial importance to attaining successful control of DBM through inoculative or inundative releases. Although parasitoids of DBM larvae and pupae are currently its principal regulators, bacteria-derived products (e.g., crystal toxins from Bacillus thuringiensis) and myco-insecticides principally based on Zoophthora radicans and Beauveria bassiana are increasingly being applied or investigated for biological control. Viruses, nematodes and microsporidia also have potential as biopesticides for DBM. When an insect pest is exposed to more than one mortality factor, there is the possibility of interactions that can enhance, limit, or limit and enhance the various aspects of effectiveness of a particular control tactic. This paper reviews the effectiveness of various parasitoids and entomopathogens against DBM, interactions among them, and their possible integration into modern IPM programs. 相似文献
32.
33.
Muhammad IQBAL Muhammad ASHRAF 《植物学报(英文版)》2005,47(11):1315-1325
The effects of presowing seed treatment with different concentrations of cytokinins (kinetin and benzylaminopurine; 100, 150, and 200 mg/L) on growth, photosynthetic capacity, and ion homeostasis were investigated in two spring wheat (Triticum aestivum L.) cultivars, namely MH-97 (salt sensitive) and Inqlab- 91 (salt tolerant). Primed and non-primed seeds were sown in a field in which NaC1 salinity of 15 dS/m was developed. Of the different concentrations of priming agents tested, the effect of a moderate concentration of kinetin (150 mg/L) was very pronounced, particularly in improving growth and grain yield, in both cultivars. In addition, priming with kinetin alleviated the adverse effect of salt stress on gaseous exchange characteristics (net CO2 assimilation rate and water use efficiency) in both cultivars. Seed priming with a moderate concentration of kinetin also altered the pattern of accumulation of Na^+ and Clˉ in the shoots, irrespective of the wheat cultivar, under conditions of salt stress. However, all other priming agents at the different concentrations tested did not show any consistent effect on ion levels, except hydropriming, which increased K^+ levels in the shoots of both cultivars under salt stress. In conclusion, a moderate concentration of kinetin showed a consistent effect in altering the growth and grain yield of both wheat cultivars, which was related to the beneficial effects of kinetin priming on water use efficiency and photosynthetic rate under conditions of salt stress. 相似文献
34.
F. Ghasemi Muhammad Sahimi J. Peinke M. Reza Rahimi Tabar 《Journal of biological physics》2006,32(2):117-128
We describe a method for analyzing the stochasticity in non-stationary data for the beat-to-beat fluctuations in the heart rates of healthy subjects, as well as those with congestive heart failure. The method analyzes the return time series of the data as a Markov process, and computes the Markov time scale, i.e., the time scale over which the data are a Markov process. We also construct an effective stochastic continuum equation for the return series. We show that the drift and diffusion coefficients, as well as the amplitude of the return time series for healthy subjects are distinct from those with CHF. Thus, the method may potentially provide a diagnostic tool for distinguishing healthy subjects from those with congestive heart failure, as it can distinguish small differences between the data for the two classes of subjects in terms of well-defined and physically-motivated quantities.
PACS: 05.10.Gg 05.40.-a, 05.45.Tp, 87.19.Hh 相似文献
35.
Waqas Wakil M. Usman Ghazanfar 《Archives Of Phytopathology And Plant Protection》2013,46(12):1236-1242
To evaluate the pathogenicity of Metarhizium anisopliae (Metschinkoff) Sorokin (Deuteromycotina: Hyphomycetes) a bioassay was designed under laboratory conditions against Rhyzopertha dominica F. (Coleoptera: Bostrychidae) on stored wheat. The fungus was applied at the dose rates of 8 × 103, 8 × 105, 8 × 107 and 8 × 109 conidia/kg of wheat and the bioassay was conducted at 25°C with 60% relative humidity. The data regarding the mortality was recorded after 7 and 14 days exposure intervals. All the treatments gave the significant mortality of R. dominica and M. anisopliae of 8 × 109 conidia/kg was found to be the most effective after a 14-day exposure interval. There was greater production of progeny when the low rate of M. anisopliae was applied to wheat. Overall, our study showed that M. anisopliae is vigorous when applied at a high dose rate which revealed an effective control of R. dominica and also played a pivotal role in the integrated pest management program (IPM) of stored wheat insect pests. 相似文献
36.
Fungal degradation of low rank coal has appeared as an alternative technique for exploitation of non-fuel options. A fungal isolate, MW1, was isolated and coal sample was subjected to fungal pretreatment. The residual coal was processed for extraction of humic acid for determining the effect of such pretreatment. Extracted humic acid was analyzed on the basis of elemental composition and spectroscopy. Fungal pretreatment caused improvement in oxygen content, E4/E6 ratio, and absorption bands related to humic materials. Conclusively, pretreatment resulted in improving chemical attributes of humic acid molecule, thus, warranting supplementary high-tech investigations for the optimization of process upscale. 相似文献
37.
Muhammad Farooq Hiroyuki Nakai Atsushi Fujimoto Hiroki Fujikawa Klaus Wilbrandt Kjaer Shahid Mahmood Baig Yutaka Shimomura 《Human genetics》2013,132(11):1253-1264
All TGF-beta family members have a prodomain that is important for secretion. Lack of secretion of a TGF-beta family member GDF5 is known to underlie some skeletal abnormalities, such as brachydactyly type C that is characterized by a huge and unexplained phenotypic variability. To search for potential phenotypic modifiers regulating secretion of GDF5, we compared cells overexpressing wild type (Wt) GDF5 and GDF5 with a novel mutation in the prodomain identified in a large Pakistani family with Brachydactyly type C and mild Grebe type chondrodyslplasia (c527T>C; p.Leu176Pro). Initial in vitro expression studies revealed that the p.Leu176Pro mutant (Mut) GDF5 was not secreted outside the cells. We subsequently showed that GDF5 was capable of forming a complex with latent transforming growth factor binding proteins, LTBP1 and LTBP2. Furthermore, secretion of LTBP1 and LTBP2 was severely impaired in cells expressing the Mut-GDF5 compared to Wt-GDF5. Finally, we demonstrated that secretion of Wt-GDF5 was inhibited by the Mut-GDF5, but only when LTBP (LTBP1 or LTBP2) was co-expressed. Based on these findings, we suggest a novel model, where the dosage of secretory co-factors or stabilizing proteins like LTBP1 and LTBP2 in the microenvironment may affect the extent of GDF5 secretion and thereby function as modifiers in phenotypes caused by GDF5 mutations. 相似文献
38.
Ritu Gupta Imran Kazmi Muhammad Afzal Ruqaiyah Khan Mohit Chauhan Fahad A. Al-Abbasi Aftab Ahmad Firoz Anwar 《Molecular and cellular biochemistry》2013,384(1-2):279-285
Sulfonamides have been reported to possess substantial antitumor activity as they act as carbonic anhydrase inhibitors. In addition, selenium appears to have a protective effect at various stages of cancer due to its antioxidant property, enhanced carcinogen detoxification, inhibition of cell invasion, and by inhibiting angiogenesis. Here, in the present study we aimed to evaluate and synergize the cytotoxic activity of sulfonamide and selenium (SM+SE) as effective therapy in the treatment of DENA-induced HCC. Hepatocarcinogeneis was induced by a single intraperitoneal injection of diethylnitrosamine (DENA) (200 mg/kg) in phosphate buffer. 30 Male Wistar rats used in this study were divided randomly into five equal groups (n = 6). DENA-administered animals showed significant alteration (p < 0.001) in liver-specific enzymes—glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), and Alpha fetoproteins (AFP), and also induced severe histopathological changes in the hepatic tissues. Interestingly, treatment with (SE+SE) (SM 30 mg/kg + SE 3 mg/kg) significantly reduced (P < 0.001, P < 0.001, P < 0.001, P < 0.001) the elevated AFP, SGOT, SGPT, and ALP levels, respectively, suggesting that combination therapy of SM+SE has a potential to treat DENA-induced liver damage. 相似文献
39.
Daniel C. B. Jeffery Brandon A. Wyse Muhammad Attiq Rehman Geoffrey W. Brown Zhiying You Roxanne Oshidari Hisao Masai Krassimir Y. Yankulov 《Nucleic acids research》2013,41(18):8475-8488
Position-effect variegation (PEV) phenotypes are characterized by the robust multigenerational repression of a gene located at a certain locus (often called gene silencing) and occasional conversions to fully active state. Consequently, the active state then persists with occasional conversions to the repressed state. These effects are mediated by the establishment and maintenance of heterochromatin or euchromatin structures, respectively. In this study, we have addressed an important but often neglected aspect of PEV: the frequency of conversions at such loci. We have developed a model and have projected various PEV scenarios based on various rates of conversions. We have also enhanced two existing assays for gene silencing in Saccharomyces cerevisiae to measure the rate of switches from repressed to active state and vice versa. We tested the validity of our methodology in Δsir1 cells and in several mutants with defects in gene silencing. The assays have revealed that the histone chaperone Chromatin Assembly Factor I is involved in the control of epigenetic conversions. Together, our model and assays provide a comprehensive methodology for further investigation of epigenetic stability and position effects. 相似文献
40.
Syed Ghulam Musharraf Arslan Ali Naik Tameem Khan Maria Yousuf Muhammad Iqbal Choudhary 《Steroids》2013,78(2):171-181
Electrospray ionization tandem mass spectrometry (ESI-MS/MS) was used to investigate the effect of different substitutions introduced during metabolism on fragmentation patterns of four anabolic steroids including methyltestosterone, methandrostenolone, cis-androsterone and adrenosterone, along with their metabolites. Collision-induced dissociation (CID) analysis was performed to correlate the major product ions of 19 steroids with structural features. The analysis is done to portray metabolic alteration, such as incorporation or reduction of double bonds, hydroxylations, and/or oxidation of hydroxyl moieties to keto functional group on steroidal skeleton which leads to drastically changed product ion spectra from the respective classes of steroids, therefore, making them difficult to identify. The comparative ESI-MS/MS study also revealed some characteristic peaks to differentiate different steroidal metabolites and can be useful for the unambiguous identification of anabolic steroids in biological fluid. Moreover, LC–ESI-MS/MS analysis of fermented extract of methyltestosterone, obtained by Macrophomina phaseolina was also investigated. 相似文献