土耳其东南部半干旱地区杏园变性土二氧化碳累积排放量的季节变化     

G. YILMAZ 《土壤圈》2012,22(3):322-332

Understanding the factors affecting the CO 2 emission from agricultural practices is crucial for global warming.A study was performed in an apricot orchard field in the experimental farm of the Harran University,Southeast Turkey,to i) quantify weekly and seasonal variations of the CO 2 emissions from a Vertisol under apricot orchard;ii) evaluate the difference in CO 2 emission between the area under trees and rows;and iii) assess the relationships between the amounts of CO 2 emissions and environmental parameters for better use and management of the soils from the view point of carbon balance and flux in a semi-arid environment under drip irrigation.Soil CO 2 emission measurements were performed during May 2008 and May 2010,from both under tree crowns (CO 2-UC) and between tree rows (CO 2-BR),on a weekly basis in southeast Turkey with a semi-arid climate.CO 2 emissions were statistically correlated with weather and soil parameters such as air temperature,relative humidity,rainfall,soil water content,and soil temperature at various depths from 5 to 100 cm.The weekly emissions ranged from 82 to 1 110 kg CO 2 ha 1 week 1 and from 96 to 782 kg CO 2 ha 1 week 1 in CO 2-UC and CO 2-BR,respectively.Increase in CO 2 emission in the second year was due to increases in mean air and soil temperatures.The weekly and monthly cumulative CO 2 emissions were positively correlated with the air and soil temperatures.Multiple linear regression analysis explained 35% and 83% variations in average weekly and monthly CO 2 emissions,by using meteorological data.Including the interaction effects of meteorological parameters in regression equations nearly doubled the variance explained by the regression models.According to stepwise regression analysis,soil and air temperatures were found to have the most significant impact on the temporal variability of the soil CO 2 emission.  相似文献   

Prevalence and Characterization of Coagulase Positive Staphylococci Isolated from Salted Anchovy     

Belgin Siriken  Tuba Yildirim  Irfan Erol  Belma Durupinar  Alper Ciftci  Ertan Emek Onuk 《Journal Of Aquatic Food Product Technology》2013,22(4):339-352

A total of 100 salted anchovy samples were used to investigate the prevalence of S. aureus and other coagulase positive Staphylococci (CPS) as well as to determine the methicillin (MR) and antibiotic resistance (AR) profile, the presence of Panton-Valentine leukocidine (PVL) toxin gene (lukS/F-PV), slime factor properties (SFP), and the genotypic relatedness of the isolates. Agar disc diffusion assay (ADDA) and microdilution broth susceptibility test (MDBST) were applied to compare the specificity and sensitivity of the MR detection methods. A total of 41 CPS isolates were detected at the 10² and 10³ CFU/g levels in contrast to S. aureus. The 16S rRNA (genus specific) was detected in all the isolates in contrast to nuc (species-specific) and lukS/F-PV genes. A total of 16/41 isolates were found to be MR by using the three methods. Polymerase chain reaction (PCR) assay was a more sensitive and reliable method for the detection of MR isolates. The antibiotic resistance rates were 75.60, 73.17, 51.21, 31.70, 12.19, and 4.87% to penicillin, ampicillin, tetracycline, erythromycin, ciprofloxacin, and clindamycin, respectively. All the isolates were sensitive to gentamicin and vancomycin. The SFP were determined in all the isolates by using Congo Red agar, and 20 different genotypes were determined by using randomly amplified polymorphic DNA (RAPD)-PCR assay.  相似文献   

Identification of Lateral Macropore Flow in a Forested Riparian Wetland through Numerical Simulation of a Subsurface Tracer Experiment     

Alper Elçi  Fred J. Molz 《Water, air, and soil pollution》2009,197(1-4):149-164

Understanding wetland hydrogeology is important as it is coupled to internal geochemical and biotic processes that ultimately determine the fate of potential contaminant inputs. Therefore, there is a need to quantitatively understand the complex hydrogeology of wetlands. The main objective of this study was to improve understanding of saturated groundwater flow in a forested riparian wetland located on a golf course in the Lower Pee Dee River Basin in South Carolina, USA. Field observations that characterize subsurface wetland flow critical to solute transport originating from storm-generated runoff are presented. Monitoring wells were installed, and slug tests were performed to measure permeabilities of the wetland soil. A field-scale bromide tracer experiment was conducted to mimic the periodic loading of nutrients caused by storm runoff. This experiment provided spatial and temporal data on solute transport that were analyzed to determine travel times in the wetland. Furthermore, a 3-D numerical, steady-state flow model (MODFLOW) was developed to simulate subsurface flow in the wetland. A particle tracking model was subsequently used to calculate solute travel times from the wetland inlet to the outlet based on flow modeling results. It was evident that observed tracer breakthrough times were not typical of these measured wetland soil matrix conductivity values. Based on surface water sampling results at the wetland outlet, tracer arrival time was about 9 h after the injection of the tracer. These results implied an apparent mean K value of 2,050 m/day, which is 152 times larger than the mean of the measured values using slug tests (13.4 m/day). Modeling efforts clearly demonstrated this implied preferential flow behavior; particle travel times resulting from the calibrated flow model were in the order of hundreds of days, while actual travel times in the wetland were in the order of hours to a few days. This significant difference in travel times was attributed to the presence of macropores in the form of dead root channels and cavities forming a pipe-flow network. The analyses presented in this study resulted in an estimate of the ratio of matrix permeability to matrix plus macropore permeability of approximately 1/150. Eventually, the tracer test and resulting travel times between various points in the wetland were critical to understanding the true wetland flow dynamics. The final conceptual model of the hydraulic properties of the wetland soils comprised a low permeability matrix containing a web of high K macropores. Simulation of tracer transport in this system was possible using a flow model with significantly elevated K values.  相似文献   

Antibacterial Bilayered Skin Patches Made of HPMA and Quaternary Poly(4-vinyl pyridine)     

İ. Alper İşoğlu  Cemre Demirkan  Mine Gül Şeker  Kadriye Tuzlakoğlu  Sevil Dinçer İşoğlu 《Fibers and Polymers》2018,19(11):2229-2236

This study aimed to produce poly(4-vinyl pyridine) and hydroxypropyl methacrylamide (HPMA)-based bilayer wound dressings materials enhancing healing mechanism for the wounds which have self-healing problem and high infection risk. These materials were designed to protect wound from secondary traumas caused microorganism invasion and do not have toxic substance release problem. Synthesis of quaternary poly(4-vinyl pyridine) (poly(Q4-VP)) which is the antibacterial layer of wound dressing material was carried out in two stages. At first stage, poly(4-vinyl pyridine) polymer was synthesized from 4-vinyl pyridine monomer by free radical polymerization. Then, poly(Q4-VP) was synthesized from poly(4-VP) by alkylation reaction with 6-bromocaproic acid. Resulted polymer was structurally characterized by FT-IR. The macroporous spongy structure, as the lower layer of wound dressing material, was prepared by cryogelation of HPMA. Then, the antibacterial polymer was electrospun onto the cryogel structure and bilayered material was obtained. Cryogel structure, fiber morphology and layer integration was examined by SEM. In order to enhance wound healing process, ascorbic acid (vitamin C) was loaded to cryogel layer and release was followed by spectrophotometrically. The antimicrobial properties of the materials were examined against Escherichia coli, Staphylococcus aureus and Candida albicans, respectively. According to the results, bilayered, antibacterial and antifungal against Staphylococcus aureus and Candida albicans, temporary wound dressings which can stimulate wound healing and have high swelling capacity were obtained successfully.  相似文献   

Gene effects of Cicer reticulatum on qualitative and quantitative traits in the cultivated chickpea          下载免费PDF全文

Alper Adak  Duygu Sari  Hatice Sari  Cengiz Toker 《Plant Breeding》2017,136(6):939-947

The gene effects of Cicer reticulatum on both double‐podding as qualitative traits and yield criteria as quantitative traits in interspecific hybridization with cultivated chickpea (Cicer arietinum) have not yet been elucidated, despite the easy acquisition of hybrid progeny between two species. This study sought to answer three questions concerning qualitative and quantitative traits in reciprocal crosses between C. arietinum and C. reticulatum. (i) Is there a similarity in the gene effects of flower colour, pigmentation and double‐podded traits in reciprocal interspecific crosses? (ii) What are the expressivity and penetrance of the double‐podded trait in interspecific crosses? (iii) Which heterosis predicts the occurrence and the extent of transgressive variation? The materials for this study were F₁, F₂ and F₃ progeny derived from a reciprocal cross between C. arietinum and C. reticulatum. As qualitative traits, purple flower colour, pigmentation and single‐podded traits in C. reticulatum were governed by a dominant single gene. Purple flower colour and pigmentation were detected to be linked traits as all progeny had the same phenotypes. As quantitative traits, yield criteria in progeny which were double‐podded had higher values than the single‐podded counterparts. Expressivity and penetrance of the double‐podding trait were superior in progeny derived from C. reticulatum × C. arietinum. The results showed that fruitful heterosis was more useful than residual heterosis in F₃ as residual heterosis was mostly negative and fruitful heterosis was suggested in self‐pollinated species such as chickpea that lacks inbreeding depression. Interspecific transgression was significant with respect to chickpea improvement because it represented a potential source of novel genetic variation.  相似文献   

Transgressive segregations for yield criteria in reciprocal interspecific crosses between <Emphasis Type="Italic">Cicer arietinum</Emphasis> L. and <Emphasis Type="Italic">C. reticulatum</Emphasis> Ladiz.     

Kerem Koseoglu  Alper Adak  Duygu Sari  Hatice Sari  F. Oncu Ceylan  Cengiz Toker 《Euphytica》2017,213(6):116

Wild Cicer species are considered to be more resistant for biotic and abiotic stresses than that of the cultivated chickpea (Cicer arietinum L.). Alien genes conferring resistance for biotic and abiotic stresses can be transferred from wild Cicer species to the cultivated chickpea but success in interspecific hybridizations has already been achieved with only two wild Cicer species. The current study was undertaken to compare fruitful heterosis in F₂ and F₃ for yield and yield criteria and to identify transgressive segregation in F₂ and F₃ in reciprocal interspecific crosses between C. arietinum and C. reticulatum Ladiz. We define fruitful heterosis as a useful parameter that can be used instead of residual heterosis. Considerable fruitful heterosis in F₂ and F₃ was found for number of seeds, pods per plant, biological yield, and seed yield. Maximum values of most of the characteristics in F₂ and F₃ were higher than that of the best parent indicating that superior progeny could be selected for yield from transgressive segregation. Progeny selection should be based on number of seeds, pods per plant, and biological yield since these characteristics had the highest direct effect on seed yield. The narrow sense heritability was found to be the highest for 100-seed weight. It was suggested that the cultivated chickpea could be used as female parent in interspecific hybridization to increase yield and yield criteria since progeny in F₂ and F₃ had better performance when it was used as female. In conclusion, interspecific hybridization of wild and cultivated chickpea can be used to improve yield and yield components and resistance to biotic and abiotic stresses as well.  相似文献   

Outfoxing the foxes     

Alper J 《Science (New York, N.Y.)》1991,253(5021):741

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Some characteristics of an avocado strain of Tobacco mosaic Virus     

Miriam Alper  M. Bar-Joseph  R. Salomon  G. Loebenstein 《Phytoparasitica》1978,6(1):15-20

An isolate of tobacco mosaic virus (TMV-A) was obtained from healthy and sunblotch-infected avocado (Persea americana) seedlings. TMV-A resembled common TMV in particle morphology, RNA size and coat protein molecular weight. TMV-A coat protein differed from common TMV coat by a minimum of 22 amino acid exchanges including the presence of one methionine, and by the absence of cysteine. Spur formation between the precipitation lines of TMV, TMV-A and a TMV antiserum indicates certain differences among the antigenic determinants of these two strains.  相似文献   

The role of chicken IL-1β, IL-6 and TNF-α in the occurrence of amyloid arthropathy     

Sevimli A  Misirlioğlu D  Yağci A  Bülbül A  Yilmaztepe A  Altunbas K 《Veterinary research communications》2008,32(7):499-508

In this study, the roles of IL-1β, IL-6 and TNF-α in amyloid arthropathic chickens with variable amounts (severe, moderate and mild) of amyloid accumulation were investigated. The presence and the levels of cytokines were evaluated in serum and in joint tissues by using ELISA and immunohistochemistry, respectively. One hundred brown layer chicks were allocated into four groups and intra-articular injections of Freund’s adjuvant were used to induce amyloid arthropathy in Groups II, III and IV. Vitamin A in group II, and methylprednisolone in Group IV were added to enhance and to reduce the severity of amyloidosis, respectively. At the end of the study, a positive correlation was observed among the incidence and severity of amyloidosis, the serum amyloid A levels and the IL-1β values both in the serum and tissues. Elevation in the tissue TNF-α levels in parallel with the severity of amyloidosis has also been noted. As a conclusion, IL-1β appears to play an important role in avian AA amyloidosis either alone or in combination with TNF-α. Further investigation is needed for understanding the role of the pro-inflammatory cytokines in avian AA amyloidosis.  相似文献   

Engineering yeast transcription machinery for improved ethanol tolerance and production     

Alper H  Moxley J  Nevoigt E  Fink GR  Stephanopoulos G 《Science (New York, N.Y.)》2006,314(5805):1565-1568

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