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排序方式: 共有105条查询结果,搜索用时 15 毫秒
1.
Elspeth Wales 《Network Security》2003,2003(9):15-17
Faced with the prospect of spam reaching such epidemic proportions that it could undermine the efficiency of email and put people off using the Internet, industry representatives and government officials are currently investigating ways in which to effectively combat the problem. 相似文献
2.
Bartlet E Blight MM Pickett JA Smart LE Turner G Woodcock CM 《Journal of chemical ecology》2004,30(5):913-925
The pollen beetle, Meligethes aeneus, which is an important pest of oilseed rape, Brassica napus, and turnip rape, B. rapa var. campestris, does not oviposit in all species of the Brassicaceae. The relationship between M. aeneus and candytuft, Iberis amara (Brassicacae), was investigated as part of chemical ecological studies into the development of control methods employing non-host-derived repellents. In choice and nonchoice feeding tests, M. aeneus completely rejected I. amara. However, in a field experiment using traps baited with flowering racemes of I. amara and B. napus, M. aeneus was attracted to both species. Gas chromatographic (GC) and GC-electroantennogram (GC-EAG) analyses indicated that the profiles of the floral volatiles of the two species are different. At least 12 compounds among the I. amara floral volatiles were detected by the M. aeneus antenna, and, of these, hexanoic acid, (E)-4,8-dimethyl-1,3,7-nonatriene and alpha-cedrene were not found among B. napus flower volatiles. Since M. aeneus is stimulated by floral volatiles to approach I. amara, but rejects it near, or at, the plant surface, I. amara does not produce repellents that could be used to manipulate M. aeneus. However, it may contain feeding deterrent(s) that could be used in "push-pull" control techniques or in the development of resistant brassicaceous crops. 相似文献
3.
Environmental stress and recovery: the geochemical record of human disturbance in New Bedford Harbor and Apponagansett Bay,Massachusetts (USA) 总被引:1,自引:0,他引:1
Latimer JS Boothman WS Pesch CE Chmura GL Pospelova V Jayaraman S 《The Science of the total environment》2003,313(1-3):153-176
Sediments record the history of contamination to estuaries. Analysis of the concentrations of toxic organic compounds, contaminant and crustal metals, organic carbon content and isotopic composition in sediment cores from two estuarine systems in Buzzards Bay allowed reconstruction of human impacts over 350 years. Vertical distributions of the contaminants correlate with changes in the nature of watershed/estuarine activities. All contaminants were highly enriched (tens to hundreds times background) in modern New Bedford Harbor sediments. Enrichment began around the turn of the 20th century for all but PCBs, which were first synthesized in the 1930s. An increase in organic carbon content and a shift of carbon isotopes toward a more terrestrial signature illustrates increasing anthropogenic impact in New Bedford as population grew along with the industrial base. Institution of environmental protection measures in the late 20th century was reflected in decreased, although still substantially elevated, concentrations of contaminants. A lack of industrial development in Apponagansett Bay resulted in much lower concentrations of the same indicators, although specific contaminants related to the early whaling industry increased significantly above background as early as the late 18th century. The similarity of indicators in older portions of cores from NBH and unimpacted Apponagansett Bay demonstrates that cores can be used to establish reference conditions as successfully as using separate sites judged a priori to represent the reference state. The historical reconstruction approach provides the basis for establishing relationships between environmental stressors and factors that drive the stressors, as well as a framework for the assessment of ecological response(s) to environmental stressors over a range of time and/or exposure scales. 相似文献
4.
The RecQ-related family of DNA helicases is required for the maintenance of genomic stability in organisms ranging from bacteria to humans. In humans, mutation of three RecQ-related helicases, BLM, WRN and RecQL4, cause the cancer-prone and premature ageing diseases of Bloom syndrome, Werner's syndrome and Rothmund-Thompson syndrome, respectively. In the fission yeast Schizosaccharomyces pombe, disruption of the rqh1(+) gene, which encodes the single Sz. pombe RecQ-related helicase, causes cells to display reduced viability and elevated levels of chromosome loss. After S-phase arrest or DNA damage, cells lacking rqh1(+) function display elevated levels of homologous recombination and defective chromosome segregation. Here we show that, like other RecQ family members, the Rqh1p protein displays 3' to 5' DNA helicase activity. Interestingly, however, unlike other RecQ family members, the helicase activity of Rqh1p is only partially required for its function in recovery from S-phase arrest or DNA damage. We also report that high cellular levels of Rqh1p result in lethal chromosome segregation defects, while more moderate levels of Rqh1p cause significantly elevated rates of chromosome loss. This suggests that careful regulation of RecQ-like protein levels in eukaryotic cells is vital for maintaining genome stability. 相似文献
5.
6.
Luchansky JB Porto-Fett AC Shoyer BA Call JE Schlosser W Shaw W Bauer N Latimer H 《Journal of food protection》2011,74(7):1054-1064
We quantified translocation of Escherichia coli O157:H7 (ECOH) and non-O157:H7 verocytotoxigenic E. coli (STEC) into beef subprimals after brine injection and subsequently monitored their viability after cooking steaks cut therefrom. Beef subprimals were inoculated on the lean side with ca. 6.0 log CFU/g of a five-strain cocktail of rifampin-resistant ECOH or kanamycin-resistant STEC, and then passed once through an automatic brine-injector tenderizer, with the lean side facing upward. Brine solutions (9.9% ± 0.3% over fresh weight) consisted of 3.3% (wt/vol) of sodium tripolyphosphate and 3.3% (wt/vol) of sodium chloride, prepared both with (Lac(+), pH = 6.76) and without (Lac(-), pH = 8.02) a 25% (vol/vol) solution of a 60% potassium lactate-sodium diacetate syrup. For all samples injected with Lac(-) or Lac(+) brine, levels of ECOH or STEC recovered from the topmost 1 cm (i.e., segment 1) of a core sample obtained from tenderized subprimals ranged from ca. 4.7 to 6.3 log CFU/g; however, it was possible to recover ECOH or STEC from all six segments of all cores tested. Next, brine-injected steaks from tenderized subprimals were cooked on a commercial open-flame gas grill to internal endpoint temperatures of either 37.8 °C (100 °F), 48.8 °C (120 °F), 60 °C (140 °F), or 71.1 °C (160 °F). Regardless of brine formulation or temperature, cooking achieved reductions (expressed as log CFU per gram) of 0.3 to 4.1 of ECOH and 0.5 to 3.6 of STEC. However, fortuitous survivors were recovered even at 71.1 °C (160 °F) for ECOH and for STEC. Thus, ECOH and STEC behaved similarly, relative to translocation and thermal destruction: Tenderization via brine injection transferred both pathogens throughout subprimals and cooking highly contaminated, brine-injected steaks on a commercial gas grill at 71.1 °C (160 °F) did not kill all cells due, primarily, to nonuniform heating (i.e., cold spots) within the meat. 相似文献
7.
Tyrrell Ashley C.; Hetz Samuel P.; Barg Carolyn J.; Latimer Amy E. 《Canadian Metallurgical Quarterly》2010,55(4):383
Studies have suggested that individuals with physical disabilities are often stigmatized and are perceived to possess less favorable physical and psychological characteristics than individuals without disability. Purpose: To investigate whether able-bodied adults' perceptions of people with different causes of spinal cord injury (SCI) are influenced by physical activity status information. Method and Participants: Each participant (N = 198) read all five vignettes describing individuals with SCI who had varying levels of physical activity participation and cause of injury information (e.g., onset-uncontrollable [hit by impaired driver] and onset-controllable [caused by impaired driving]). After reading each vignette, participants completed a 12-item Warmth and Competence Questionnaire to evaluate each target. One-way repeated measures multivariate analyses of variance were conducted to examine the within-subjects differences. Results: Physically active individuals with onset-uncontrollable SCI were rated most favorably on warmth and competence. Physically active individuals with onset-controllable SCI also were rated more favorably on warmth and competence than physically inactive targets with onset-controllable SCI. Conclusion: A physically active lifestyle may be beneficial in managing the stigma experienced by individuals with both onset-controllable and onset-uncontrollable SCI. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
Elspeth Wales 《Computer Fraud & Security》2003,2003(5):6-8
Despite the tendency for businesses to keep fraud to themselves, the consensus is that the problem is becoming worse. On the plus side though software solutions that can detect potential fraudulent activity are evolving in their scope and ability to automatically track transactions in real-time. 相似文献
9.
Elspeth Wales 《Computer Fraud & Security》2002,2002(8):14-16
Not so long ago the implementation of security technology was viewed by outsiders as a black art, characterized by mumbo jumbo which only those few in the know understood. But times are changing, businesses are increasingly using the Internet to access, store and transfer valuable information but in doing so they are exposing themselves to the risks of security breaches. 相似文献
10.
Ainge James A.; Keating Glenda L.; Latimer Mary P.; Winn Philip 《Canadian Metallurgical Quarterly》2006,120(3):563
Pedunculopontine tegmental nucleus (PPTg) lesions in rodents lead to increased sucrose consumption, but the psychological deficit behind this remains uncertain. To understand better the relationship between consumption of, and motivation for, sucrose, the authors trained rats to traverse a runway for 20% or 4% sucrose solution; after 7 days, concentrations were reversed. Control rats consumed more 20% than 4% sucrose solution and promptly altered run times in response to concentration change. PPTg-lesioned rats consumed normal quantities of 4% but more 20% sucrose solution than controls and took longer to alter their runway time following the concentration change. These data suggest that lesions of the PPTg do not alter motivation per se and might be better understood as inducing a response selection deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献