Response of selected water chemical quality parameters to slight thinning in a mature oak–beech forest ecosystem under sub-humid climate conditions     

Yurtseven  Ibrahim  G&#;kbulak  Ferhat  Serengil  Yusuf  Erdo&#;an  Bet&#;l Uygur  &#;z&#;elik  Mehmet Said  &#;eng&#;n&#;l  Kamil  &#;zhan  S&#;leyman 《European Journal of Forest Research》2017,136(4):653-664

The objective of this study was to determine the effect of 18% thinning on streamflow nutrient flux from a mature oak–beech forest ecosystem by paired watershed approach. Two experimental watersheds including control (W-I) and treatment (W-IV) watersheds were used in the study. The experimental watersheds were monitored about 6 years from 2006 to 2011 for the calibration period and 4 years from 2012 to 2015 for the treatment period. The forest in the treatment watershed was thinned between October and December in 2011, and the forest in the control watershed was left untreated. Water grab samples were collected from the streams in the watersheds on weekly basis during both the calibration and treatment periods and analyzed for calcium (Ca²⁺), magnesium (Mg²⁺), Kjeldahl nitrogen (KN), sodium (Na⁺), potassium (K⁺), iron (Fe³⁺), aluminum (Al³⁺), ammonium nitrogen (NH₄ ⁺-N), and sulfate (SO₄ ²⁻). The simple linear regression equations were developed between mean monthly nutrient fluxes of two watersheds in the calibration period with significantly high correlation coefficients, and they were used to estimate nutrient fluxes from the treatment watershed during the treatment period as if thinning had not been applied. The changes in the monthly nutrient fluxes were estimated as the differences between measured and values calculated with the linear regression equations. Results showed that removal of 18% standing timber volume did not significantly change nutrient exports except for KN and Na⁺ from the treatment watershed.

  相似文献   

Orthogonal cutting mechanics of maple: modeling a solid wood-cutting process     

Jean-Philippe?Costes  Pak Lim?Ko  Tony?Ji  Cyrille?Decès-PetitEmail author  Yusuf?Altintas 《Journal of Wood Science》2004,50(1):28-34

The experimental results of orthogonal cutting of maple and the modeling of the cutting mechanics are presented. The tool cutting forces were measured for different feed rates. A set of equations relating the tangential and feed forces to the tool edge width and feed rate (chip thickness) to calculate the chip and edge cutting force coefficients was developed. Then the chip force and edge force coefficients were calculated from experimentally obtained cutting forces and were plotted in a polar-coordinate system with respect to the fiber orientation of the maple disk. The polar-coordinate presentation of the cutting force results and the calculated cutting force coefficients provides an excellent visual appreciation of the relation between the cutting forces and the wood fiber orientation. Chips were also collected from various sectors of the wood disk. This analysis further identified the effects of fiber orientation and cutting forces on the types of chip formed and hence the cutting mechanics involved. By applying the calculated cutting coefficients for each tool orientation (in respect to the grain) it is possible to predict the feed and tangential forces for any feed rates. There is good agreement between the predicted and measured cutting forces.  相似文献   

西昆仑山2个海拔位点可培养细菌多样性分析     

玛丽帕·吐达洪  阿不都外力·阿布都热依木  孜来古丽·米吉提  卡依尔·玉素甫  马丽艳木·阿木东  艾尼江·尔斯曼  祖母拉提·阿布都热依木  艾尔肯·热合曼 《干旱区研究》2011,28(6):1071-1080

以西昆仑山2个海拔样点的土样为对象,利用（LB和TSA）2种培养基,基于16S rRNA基因序列的系统发育,采用纯培养法对其可培养细菌多样性进行研究。2样点中共分离到91株细菌,分为25个属,52个种。厚壁菌门（Firmicutes）占总菌数的48.75%,放线菌门（Actinobacteria）占36.25%,γ-变...  相似文献   

The distribution of important sero-complexes of flaviviruses in Malaysia     

Kumar  Kiven  Arshad  Siti Suri  Toung  Ooi Peck  Abba  Yusuf  Selvarajah  Gayathri Thevi  Abu  Jalila  A.R  Yasmin  Ong  Bee Lee  Bande  Faruku 《Tropical animal health and production》2019,51(3):495-506

Tropical Animal Health and Production - Flaviviruses (FVs) are arthropod-borne viruses of medical and veterinary importance. Numerous species of FVs have been isolated from various host; mainly...  相似文献   

Genome analysis of methicillin‐resistant Staphylococcus aureus isolated from pigs: Detection of the clonal lineage ST398 in Cameroon and South Africa     

Luria Leslie Founou  Raspail Carrel Founou  Mushal Allam  Arshad Ismail  Cyrille Finyom Djoko  Sabiha Yusuf Essack 《Zoonoses and public health》2019,66(5):512-525

Food animals are considered reservoirs of methicillin‐resistant Staphylococcus aureus (MRSA) and are implicated in their zoonotic transmission in the farm‐to‐plate continuum. LA‐MRSA has been reported as a zoonotic agent that has the potential to spread to humans and may cause infections in at‐risk groups. In this study, whole genome sequencing was used to describe the genetic environment (resistance mechanisms, virulence factors and mobile genetic elements) and investigate the genetic lineages of MRSA isolates from pigs in Cameroonian and South African abattoirs. During March–October 2016, 288 nasal and rectal pooled samples from 432 pigs as well as nasal and hand swabs from 82 humans were collected. Genomic DNA was sequenced using an Illumina MiSeq platform. Generated reads were de novo‐assembled using the Qiagen CLC Genomics Workbench and SPAdes. The assembled contigs were annotated, and antibiotic resistance genes, virulence factors, plasmids, SCCmec and phage elements were identified with ResFinder, Virulence Finder, PlasmidFinder, SCCmec Finder and PHAST, respectively. Core genome single nucleotide analysis was undertaken to assess clonal relatedness among isolates. A lower MRSA prevalence was observed in pigs in Cameroon (n = 1/13; 0.07%) compared with South Africa (n = 4/22; 18.18%), and none of the workers were colonized by MRSA. Genome analysis identified various antibiotic resistance genes along with six virulence factors in all isolates. All MRSA isolates belonged to the clonal lineage ST398 (spa‐type t011) and harboured the type Vc SCCmec and several plasmids. Our study shows that the livestock‐associated MRSA clonal lineage ST398 is already present in both Cameroon and South Africa and is probably underestimated in the absence of molecular epidemiological studies. It reveals the serious food safety and public health threat associated with this animal strain and underscores the need for interventions to contain this resistant clone.  相似文献   

Electricity and water desalination: Separate sites offer value     

Dr. I. Moch Jr.  Fred Depenbrock  Yusuf Mussalli 《Water, air, and soil pollution》1996,90(1-2):231-241

For the fuel type and water situation in the Middle East, the case is strong for the use of combined cycle technology for power generation and reverse osmosis for potable water production, where each are sited for their maximum economic benefit and interconnected by electric power transmission. Because of the fuel efficiency of Combined Cycle generation technology, its use of liquid/gas fuels and its low need for cooling water, it can be optimized for cost away from cities. Conversely, water desalination by reverse osmosis can be sited in optimal locations to take advantage of its modularity and to minimize water pipeline needs. Electric power transmission provides an inexpensive and flexible means to connect these two technologies. Together these technologies may offer an overall minimum cost approach, better than the combining of electric power and water desalination at one location, where power to water ratios must be fixed, independent of need, for optimum efficiency. The use of reverse osmosis with power generation has other, important ancillary benefits over using distillation and power combinations. These advantages include abatement of environmental pollution, delivery of potable water at reasonable drinking temperatures, lower total energy consumption, more efficient land use and less demanding operator skills.  相似文献   

尼日利亚稻田养鱼加灯光诱虫应用效果分析   总被引：1，自引：1，他引：1  

晏宏  田景权  王泽伦  帅启富  亚伯于索夫 《山地农业生物学报》2006,25(5):407-411,464

在尼日利亚科基州进行不同沟凼的稻田养鱼加灯光诱虫应用研究，其沟凼模式分围沟和十字沟，灯光以煤油灯代替电灯，鱼稻品种均为当地常见品种。结果表明，开挖占稻田面积10％～15％不同类型的鱼沟或鱼坑，其投入成本相同，鱼稻产量相近，均比单纯稻田收入增加3．5～4．5倍。示范成果还进一步验证了以往在尼日利亚进行的灯光诱虫试验结论，即在稻田养鱼中增加灯光诱虫，能够将有害昆虫变为鱼的全价饲料，减少稻田的病虫害，鱼、稻分别增产14％和9．5％，达到经济效益和生态效益双丰收。  相似文献   

Can diphenhydramine prevent organophosphate-induced acute pancreatitis? An experimental study in rats     

Yusuf Yürümez  Yücel Yavuz  ?. Hakk? Çiftçi  Mehmet Emin Büyükokuro?lu 《Pesticide biochemistry and physiology》2007,87(3):271-275

Acute pancreatitis (AP) is a well known complication of organophosphate (OP) poisoning and the true incidence is unknown; but, may be more common than clinically suspected. Previous studies suggest that Diphenhydramine (DPH) may be useful as an alternative or adjunctive therapy in OP poisoning. The aim of this experimental study was to investigate whether DPH could prevent or diminish pancreatic damage caused by OP poisoning as defined by histologic findings, and serum interleukin 10 (IL-10) and tumor necrosis factor alpha (TNF-α) levels. Twenty-four Sprague- Dawley rats were divided into equal three groups. Group 1 did not receive any agent during the experiment. Group 2 received 0.8 g/kg fenthion subcutaneously followed by 3 ml/kg normal saline intramuscularly, 30 min later. Group 3 received 0.8 g/kg fenthion subcutaneously, followed by 30 mg/kg DPH intramuscularly, 30 min later. Twenty-four hours later, pancreatic tissues were excised and blood samples were taken. After blood samples were taken by cardiac puncture, the animals were sacrificed. Treatment with DPH significantly decreased the serum TNF-α and increased the serum IL-10 levels. DPH significantly reduced pancreatic damage, including edema, inflammation, vacuolization and necrosis, as determined by pathologic scoring. The present study show that DPH decreased the severity of OP induced AP in rats. This effects may be related to a decrease of TNF-α level and increase of IL-10 level.  相似文献   

Kinetics and Energetics of Azo Dye Decolorization by Pycnoporus sanguineus     

M. S. M. Annuar  S. Adnan  S. Vikineswary  Y. Chisti 《Water, air, and soil pollution》2009,202(1-4):179-188

Trypan Blue, an azo dye, was decolorized using the self-immobilizing fungal biomass of Pycnoporus sanguineus. The extent and the rate of dye decolorization were directly proportional to the initial dye concentration (20–60 mg L^?1) and the reaction temperature (25–45°C). Mass transfer within and outside the pellets did not limit dye degradation. The apparent kinetics of the decolorization reaction followed a first-order behavior. Activation energy for the biological decolorization was calculated at 23 kJ mol^?1. The decolorization process was endothermic with the enthalpy and entropy values calculated at 45.6 kJ mol^?1 and 146 J mol^?1 K^?1, respectively. Based on the value of Gibbs free energy change, the decolorization reaction under the conditions studied was non-spontaneous below 39°C but was spontaneous at higher temperatures.  相似文献   

摘叶和喷施外源过氧化氢对库尔勒香梨粗皮果形成的影响     

史智勇  艾沙江·买买提  仙米斯娅·塔依甫  曹艺洁  玉苏甫·阿不力提甫 《新疆农业科学》2023,60(4):889-896

【目的】研究库尔勒香梨上可能诱导粗皮果形成的胁迫因子。【方法】基于分析库尔勒香梨粗皮果形成的基础上,对生长期的库尔勒香梨枝条采用50%程度地摘叶、外源喷施250 mmol/L的H₂O₂2种人为逆境处理,在成熟期统计处理枝条上粗皮果率,对不同处理的果实进行组织切片染色,检测生理指标。【结果】库尔勒香梨成熟期对照组的粗皮果比率为18.10%,H₂O₂喷施和摘叶处理的粗皮果率分别为51.93%、29.52%;3组果实中果皮中的木质素含量分别为3.4%、4.9%、3.9%,果肉中的木质素含量分别为1.5%、1.7%、2.0%,2个处理组均提高了库尔勒香梨的粗皮果率以及果实中的木质素含量。H₂O₂喷施后外果皮的丙二醛(MDA)和活性氧(H₂O₂和O^-₂)含量显著增加,分别为对照的1.7和2.9倍。与之相应,库尔勒香梨果皮可溶性糖、淀粉等渗透调节物质含量也显著增加,分别为对照的1....  相似文献