Government of Portugal     

Gates DM 《Science (New York, N.Y.)》1959,129(3340):62-64

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Systematic Collections     

Gates GE 《Science (New York, N.Y.)》1960,132(3430):832-834

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HAILSTONE DAMAGE TO BIRDS     

Gates WH 《Science (New York, N.Y.)》1933,78(2021):263-264

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Bacterial rhodopsin: evidence for a new type of phototrophy in the sea     

Béjà O  Aravind L  Koonin EV  Suzuki MT  Hadd A  Nguyen LP  Jovanovich SB  Gates CM  Feldman RA  Spudich JL  Spudich EN  DeLong EF 《Science (New York, N.Y.)》2000,289(5486):1902-1906

Extremely halophilic archaea contain retinal-binding integral membrane proteins called bacteriorhodopsins that function as light-driven proton pumps. So far, bacteriorhodopsins capable of generating a chemiosmotic membrane potential in response to light have been demonstrated only in halophilic archaea. We describe here a type of rhodopsin derived from bacteria that was discovered through genomic analyses of naturally occuring marine bacterioplankton. The bacterial rhodopsin was encoded in the genome of an uncultivated gamma-proteobacterium and shared highest amino acid sequence similarity with archaeal rhodopsins. The protein was functionally expressed in Escherichia coli and bound retinal to form an active, light-driven proton pump. The new rhodopsin exhibited a photochemical reaction cycle with intermediates and kinetics characteristic of archaeal proton-pumping rhodopsins. Our results demonstrate that archaeal-like rhodopsins are broadly distributed among different taxa, including members of the domain Bacteria. Our data also indicate that a previously unsuspected mode of bacterially mediated light-driven energy generation may commonly occur in oceanic surface waters worldwide.  相似文献   

Investigations on N-nitrosopyrrolidine in dry-cured bacon     

W Fiddler  J W Pensabene  R A Gates  J M Foster  W J Smith 《Journal of the Association of Official Analytical Chemists》1989,72(1):19-22

Dry-cured or "country-style" bacon is a low volume specialty product typically made by small producers whose production practices vary widely. These practices include the direct application of dry-cure formulations containing varying concentrations of salt, sugar, flavoring agents, sodium nitrite, and sometimes sodium nitrate, and the use of lengthy curing and processing times. Because of the possibility of generating higher levels of N-nitrosopyrrolidine (NPYR) after frying in this product type compared with pump-cured bacon, an investigation was carried out on dry-cured bacon obtained from cooperating state or federally inspected establishments. Three different samples from each of the 16 plants were analyzed. Only one sample from each of 2 different producers exceeded the Food Safety and Inspection Service (FSIS) action level of 17 ppb NPYR, indicating that the majority of samples tested were in compliance. A significant correlation (P less than 0.01) was found between residual NaNO2 prior to frying and NPYR after frying. The elimination of added nitrate in the dry-cure formulations is recommended.  相似文献   

Bioavailability of an organophosphorus pesticide,fenamiphos, sorbed on an organo clay     

Singh N  Megharaj M  Gates WP  Churchman GJ  Anderson J  Kookana RS  Naidu R  Chen Z  Slade PG  Sethunathan N 《Journal of agricultural and food chemistry》2003,51(9):2653-2658

Hydrolysis of an insecticide/nematicide, fenamiphos [ethyl-3-methyl-4-(methylthio)phenyl-(1-methylethyl)phosphoramidate], immobilized through sorption by cetyltrimethylammonium-exchanged montmorillonite (CTMA-clay) by a soil bacterium, Brevibacterium sp., was examined. X-ray diffraction analysis, infrared spectra, and a negative electrophoretic mobility strongly indicated that fenamiphos was intercalated within the bacterially inaccessible interlayer spaces of CTMA-clay. The bacterium hydrolyzed, within 24 h, 82% of the fenamiphos sorbed by the CTMA-clay complex. There was a concomitant accumulation of hydrolysis product, fenamiphos phenol, in nearly stoichiometric amounts. During the same period, in abiotic (uninoculated) controls, 4.6% of the sorbed insecticide was released into the aqueous phase as compared to 6.0% of the sorbed fenamiphos in another abiotic control where activated carbon, a sink for desorbed fenamiphos, was present. Thus, within 24 h, the bacterium hydrolyzed 77% more fenamiphos sorbed by organo clay than the amounts desorbed in abiotic controls. Such rapid degradation of an intercalated pesticide by a bacterium has not been reported before. Evidence indicated that extracellular enzymes produced by the bacterium rapidly hydrolyzed the nondesorbable fenamiphos, even when the enzyme itself was sorbed. Fenamiphos strongly sorbed to an organo clay appears to be readily available for exceptionally rapid degradation by the bacterium.  相似文献   

Necropsy and laboratory findings in free-living deer in South Dakota.     

D E Reed  H Shave  M E Bergeland  C E Gates 《Journal of the American Veterinary Medical Association》1976,169(9):975-979

In a diagnostic survey of diseases in wild white-tailed deer (62 cases) and mule deer (12 cases) the most common findings were traumatic injury (20%), nontraumatic hemorrhage (13%), polioencephalomalacia (11%), and bacterial infections (9%). Although epizootic hemorrhagic disease was suspected in several cases, the virus was isolated from only 1 white-tailed deer.  相似文献   

Insecticidal activity of certain benzodioxolyl carbamates     

P. J. Brooker  P. S. Gates  J. Gillon  G. T. Newbold  D. T. Saggers 《Pest management science》1972,3(6):735-744

A series of benzodioxolyl carbamates has been prepared and evaluated in the laboratory for insecticidal activity against a range of ten species. The results indicated that this was optimal with the 4-benzodioxolyl carbamates with a 2,2-dialkyl substitution. The most promising of these on the basis of cost-effectiveness was 2,2-dimethyl-1,3-benzodioxol-4-yl methylcarbamate, bendiocarb, which is being developed commercially for the control of household pests.  相似文献   

Community composition, species richness, and abundance of birds in field margins of central Mexico: local and landscape-scale effects     

Iriana Zuria  J. Edward Gates 《Agroforestry Systems》2013,87(2):377-393

Field margin vegetation is among the last vestiges of semi-natural habitat for birds in many agricultural landscapes of tropical regions. However, field margins differ in size, structure, and flora, and their value to birds depends on all these factors and on species-specific habitat preferences. Therefore, we analyzed data on resident and neotropical migratory birds found in 40 field margins of the agricultural landscape of El Bajío, Guanajuato, Mexico. The structural and botanical characteristics of the field margin, and those of the adjacent landscape, were related to bird species richness and abundance. We recorded 61 species of birds of which 36 were migratory. Locally, the size of the field margin (width, height, volume), its vegetative vertical complexity, and the abundance of trees and tree species had a positive effect on bird species richness and abundance. Native trees, especially mesquites, were especially important for many birds observed foraging, nesting, and perching. The most important landscape-scale variables were the density of hedgerows around field margins and the distance to natural vegetation remnants (scrub forest). Bird species richness and abundance were positively affected by the length of the hedgerows within 100 and 200-m-radius circles centered on each field margin. Field margins closer to natural vegetation also had more bird species and individuals. On the basis of our results, we suggest some general management recommendations for improving the habitat for birds in tropical agricultural landscapes.  相似文献   

Estimating the level of disease risk and biosecurity on commercial poultry farms in New Zealand     

SS Greening  K Mulqueen  TG Rawdon  NP French  MC Gates 《New Zealand veterinary journal》2020,68(5):261-271

ABSTRACT

Aims: To collect baseline data on the contact risk pathways and biosecurity practices of commercial poultry farms in New Zealand, investigate the relationship between the farm-level disease contact risks and biosecurity practices, and identify important poultry health concerns of producers.

Methods: A cross-sectional survey of all registered New Zealand commercial poultry operations was conducted in 2016 collecting information on farm demographics, biosecurity practices, and contact risk pathways. Survey responses were used to generate an unweighted subjective disease risk score based on eight risk criteria and a subjective biosecurity score based on the frequency with which producers reported implementing seven biosecurity measures. Producer opinions towards poultry health issues were also determined.

Results: Responses to the survey response were obtained from 120/414 (29.0%) producers, including 57/157 (36.3%) broiler, 33/169 (19.5%) layer, 24/55 (44%) breeder, and 6/32 (19%) other poultry production types. Median disease risk scores differed between production types (p?<?0.001) and were lowest for breeder enterprises. The greatest risk for layer and broiler enterprises was from the potential movement of employees between sheds, and for breeder enterprises was the on- and off-farm movement of goods and services. Median biosecurity scores also differed between production types (p?<?0.001), and were highest for breeder and broiler enterprises. Across all sectors there was no statistical correlation between biosecurity scores and disease risk scores. Producers showed a high level of concern over effectively managing biosecurity measures.

Conclusions: The uptake of biosecurity measures in the commercial poultry farms surveyed was highly variable, with some having very low scores despite significant potential disease contact risks. This may be related to the low prevalence or absence of many important infectious poultry diseases in New Zealand leading farmers to believe there is a limited need to maintain good biosecurity as well as farmer uncertainty around the efficacy of different biosecurity measures. Further research is needed to understand barriers towards biosecurity adoption including evaluating the cost-effectiveness of biosecurity interventions.  相似文献