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71.
Maryam Tabatabaei John B. Loomis Daniel W. McCollum 《Journal of Sustainable Forestry》2013,32(8):720-737
We estimated Colorado households’ nonmarket values for two forest management options for reducing intensity of future wildfires and associated nonmarket environmental effects wildfires. The first policy is the traditional harvesting of pine beetle-killed trees and burning of the slash piles of residual materials on-site. The second involves harvesting but moving the residual material off-site and converting it into biochar, thus reducing some of the risk and environmental effects associated with burning on-site. A contingent valuation method mail survey was used to evaluate these two management options. The survey achieved a 47% response rate. We used a nonparametric Turnbull estimator to calculate the willingness to pay (WTP) for burn on-site and off-site biochar conversion. The calculated WTP for burn on-site and off-site biochar conversion options (beyond the cost of the status quo level of forest treatment) is $411 and $470 per household per year, respectively. 相似文献
72.
Background – Antimicrobial peptides (AMPs) have a pivotal role in cutaneous innate immunity. They are present in the skin of many animals, including mammals, and are both constitutively present and inducible by infection and injury. Functions – Antimicrobial peptides exhibit antimicrobial activity against bacteria, viruses, fungi and parasites, with different potencies depending on their peptide structure. They also act as multifunctional effector molecules that influence diverse cellular processes, including cell migration, proliferation and differentiation, cytokine production, angiogenesis and wound healing. Suppressed AMP production has been associated with increased susceptibility to microbial insults and the pathogenesis of atopic dermatitis. This review highlights recent observations on the expression and role of AMPs, particularly the AMPs cathelicidin and β‐defensin, in healthy and diseased skin. 相似文献
73.
Background: To develop a new green approach for biosynthesis of silver nanoparticles, myconanotechnology has been represented as a novel field of study in nanotechnology. In this study, we have reported the extracellular synthesis of highly stable silver nanoparticles using three species of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. Methods: Clinical strains of these species were grown in a liquid medium containing mineral salt and incubated at 25°C for 5-7 days. The cell-free filtrate of each culture was obtained and subjected to synthesize silver nanoparticles in the presence of 1 mM AgNO3. Results: The reduction of Ag+ ions in metal nanoparticles was investigated virtually by tracing the solution color which was switched into reddish-light brown after 72 h. For T. mentagrophytes, a UV-visible spectra demonstrating a strong, quite narrow peak located between 422 and 425 nm was obtained. For M. canis, a fairly wide peak centering at 441 nm and for T. rubrum, a weak spectrum to decipher were observed. According to transmission electron microscopy (TEM) results, fairly uniform, spherical, and small in size with almost less than 50 nm particles were forms in case of T.
mentagrophytes. For the other two species, TEM images showed existence of small spherical nanosilvers but not as small as nanoparticles synthesized by T. mentagrophytes. Conclusion: We observed that species belong to a single genus of the fungi have variable ability to synthesize silver nanoparticles extracellulary with different efficiency. Furthermore, the extracellular synthesis may make the process simpler and easier for following processes.Key Words: Nanoparticles, Dermatophytes, Extracellular biosynthesis 相似文献
74.
Maryam Rahimi Shima Fayaz Armaghan Fard-Esfahani Mohammad Hossein Modarressi Seyed Mohammad Akrami Pezhman Fard-Esfahani 《Iranian Biomedical Journal》2012,16(4):218-222
Background
The aim of this study was to understand any association between differentiated thyroid carcinoma (DTC) and Ile3434Thr XRCC7 gene polymorphism (GenBank accession number: rs7830743). DTC is the most prevalent thyroid neoplasm, which includes papillary and follicular cell carcinoma. XRCC7 gene encodes a protein that functions in non-homologous end joining DNA repair pathway. Non-synonymous polymorphisms in this gene may alter DNA repair capacity of the cell and change the risk of developing cancers.Methods
DTC patients (n = 173) and cancer free individuals (n = 204) were enrolled in a case-control study. The Ile3434Thr polymorphic alleles were discriminated by using amplification refractory mutation system-PCR method. The frequencies of this single nucleotide polymorphism in case and control groups were compared. Also, risk ratio for developing DTC in dichotomized genotypes was estimated by multivariate logistic regression analysis.Results
Dichotomized genotypes into those with and without the 3434Thr allele showed that this allele was associated with DTC (OR [odd ratio]: 1.89, 95% confidence interval (CI) = 1.29-2.79, P<0.001). Also, TC genotype was significantly associated with increased risk of DTC (OR: 2.42, 95% CI = 1.55-3.81, P = 0.0001) in individuals carrying this genotype.Conclusion
Allele 3434Thr in XRCC7 gene might be associated with differentiated thyroid cancer risk. Further studies with larger samples are needed to verify these initial findings. Key Words: DNA repair enzymes, Thyroid neoplasms, Genetic polymorphism 相似文献75.
76.
Selenium (Se) is an essential element for human and livestock with antioxidant and anticancer characteristics. Although Se is not an essential element for plants, it has been reported that it can improve plant growth. This experiment was conducted at the Isfahan University of Technology in winter 2010. The experiment was factorial based on a completely randomized design (CRD) with four replications. Se was added to nutrient solution in four concentrations 2, 4, and 6 mg/L sodium selenite (Na2SeO3). Root volume, fresh and dry weights of shoots and roots, number and weight of fruits, chlorophyll content, and photosynthesis traits [photosynthesis rate, stomata internal carbon dioxide (CO2) concentration, stomata conductance] were measured. Results showed that Se increased root dry weight. Fresh and dry weights of shoot increased in the 2 mg/L Se treatment and decreased at the higher level of Se. Chlorophyll content and photosynthesis rate were not affected by Se. Stomata internal CO2 concentration and stomata conductance decreased by Se addition. Overall, Se at 2 mg/L application rate was effective in some physiological characteristics of cucumber. 相似文献
77.
There are inconsistent results for the association of Mycobacterium avium subspecies paratuberculosis (MAP) infection with production and reproduction in dairy cows. Determination of these associations in each region is essential
to encourage participation of dairy cattle producers in disease control programs. This study was conducted in Shiraz, southern
Iran, to quantify the association of subclinical MAP infection with 305-day milk production and calving interval in Iranian
Holsteins. A total of 21 dairy herds were selected for the study and in each herd, quarter milk samples were collected from
ten to 12 dairy cows for PCR analysis. Data about parity, calving interval, length of lactation period, total milk production
and 305-day milk production were also provided for each animal. Overall, 252 individual milk samples were collected. Herd-
and individual-level prevalence of MAP infection were 23.8% (95% CI, 6.2–41.4%) and 3.2% (95% CI, 1.3–5.1%), respectively
based on IS900 nested PCR. The results for 305-day milk production revealed a 248 kg reduction in positive cows compared with
negative ones (P = 0.009). When cows from positive herds were compared with cows from negative herds, a 335-kg reduction in 305-day milk production
(P = 0.005) and a 30-day increase in calving interval (P = 0.057) were observed in the former group. These findings support the previous results that paratuberculosis infection is
negatively associated with the performance of the animals. 相似文献
78.
Pegah Khosravi Maryam Jafarkhani Kermani Ghorban Ali Nematzadeh Mohammad Reza Bihamta Kazutomo Yokoya 《Euphytica》2008,160(2):267-275
Dinitroanilines represent a class of compounds that are widely used in herbicide formulations as they depolymerise plant microtubles,
causing chromosome doubling. The potential of microtubule depolymerising herbicides trifluralin, oryzalin, and amiprophosmethyl
(APM) for in vitro chromosome doubling of Rosa was studied. Five concentrations (0, 3, 6, 12 and 24 μM) and three exposure periods (12, 24 and 48 h) for each of the compounds
were compared. Oryzalin, trifluralin and APM were not significantly different in their ability to induce chromosome doubling
of R. hybrida cv Iceberg. At concentration of 6 μM and exposure period of 24 h, chromosome doubling of R. hybrida cv Iceberg was not significantly different with each of the polyplodising agents. At higher concentration (24 μM) and longer
exposure period (48 h), 66.7% and 62.5% chromosome doubling was achieved with APM and trifluralin, respectively. However,
the application of 6 μM oryzalin to R. persica (2n = 2x), R. hybrida cv Iceberg (2n = 3x) and R. hybrida cv Akito (2n = 4x), resulted in 60.0%, 6.3% and 0% chromosome doubling, respectively, which suggest that chromosome doubling is genotype dependent
and plants with lower ploidy level have a higher propensity for chromosome doubling. Flow cytometry results at 18 and 24 weeks
after herbicide treatment, indicated that the best time to test the treated plants was after 24 weeks. 相似文献
79.
80.
More accurate estimation of crop evapotranspiration(ET_c)in a regional scale has always been one of the most important challenges.Temporal and spatial monitoring of ET_(c )using satellite images can help to enhance accuracy of estimations.In this study,the(ET_c)_(rice) maps were produced by using statistical/experimental methods based on crop coefficient(K_c)maps derived from vegetation index(Ⅵ).K_c was estimated using four methods,including linear relationship between K_c and Ⅵ(K_c-Ⅵ),calibrated model of K_c-Ⅵ,linear relationship between K_(cb)(the basal crop coefficient)and Ⅵ(K_(cb)-Ⅵ),and calibrated model of K_(cb)-Ⅵ.The results showed that calibrated model of K_c-Ⅵ had a better performance compared to the other methods,with normalized root mean square errors(NRMSE),mean absolute error and root mean square error being 5.7%,0.05 mm/d and 0.06mm/d,respectively.(ET_c)_(rice) maps were produced by using calibrated model of K_c-Ⅵ and reference evapotranspiration(ET_0)from FAO Penman-Monteith method.The NRMSE was 21.3%for using FAO Penman-Monteith method.Therefore,calibrated K_c-Ⅵ model in combining with ET_0 based on the Landsat 7 ETM+images could be provided a good estimation of(ET_c)_(rice) in regional scale,and can be applied to estimate water requirement due to the free and facilitate access. 相似文献