A glycine-dependent riboswitch that uses cooperative binding to control gene expression

We identified a previously unknown riboswitch class in bacteria that is selectively triggered by glycine. A representative of these glycine-sensing RNAs from Bacillus subtilis operates as a rare genetic on switch for the gcvT operon, which codes for proteins that form the glycine cleavage system. Most glycine riboswitches integrate two ligand-binding domains that function cooperatively to more closely approximate a two-state genetic switch. This advanced form of riboswitch may have evolved to ensure that excess glycine is efficiently used to provide carbon flux through the citric acid cycle and maintain adequate amounts of the amino acid for protein synthesis. Thus, riboswitches perform key regulatory roles and exhibit complex performance characteristics that previously had been observed only with protein factors.     

Late Pliocene Homo and hominid land use from Western Olduvai Gorge,Tanzania

Excavation in the previously little-explored western portion of Olduvai Gorge indicates that hominid land use of the eastern paleobasin extended at least episodically to the west. Finds included a dentally complete Homo maxilla (OH 65) with lower face, Oldowan stone artifacts, and butchery-marked bones dated to be between 1.84 and 1.79 million years old. The hominid shows strong affinities to the KNM ER 1470 cranium from Kenya (Homo rudolfensis), a morphotype previously unrecognized at Olduvai. ER 1470 and OH 65 can be accommodated in the H. habilis holotype, casting doubt on H. rudolfensis as a biologically valid taxon.     

Investigating design and provision of access facilities as a barrier to woodland use

A key policy objective of many European Governments and their forestry departments is socially inclusive use of woodlands as use is a pre-requisite to enjoying many of the benefits afforded by woodland. However, access to woodlands is unequally distributed across British society and research suggests disconnect between the facilities provided and their suitability-for-use, given the wide range of reasons for visiting woodland. This research sought to inform woodland management and complement research into barriers to accessing woodland by investigating whether the design and provision of core access facilities may preclude certain user-groups. The research was carried out on the public forest estate of England; although the results are applicable to any woodland where public access is encouraged. The generic findings are applicable also to other greenspace types. Preferences in design were strongly influenced by the instrumentality (functionality) and aesthetic of an item – whether it was in-keeping with the woodland setting. Facility provision and upkeep are also important to woodland users. The study suggests that small changes in facility provision, including greater emphasis on naturalistic and rustic designs, provision of a range of pathway surface types and reducing the urbanisation of woodland, could increase the appeal of woodland to a wider demographic. Woodlands can fulfil a wide range of social functions. Where this is desirable, the woodland (new or existing) should be appropriately designed to reflect these intended roles and functions. This will require a range of facilities sympathetically provided.     

Farm management optimization using chance constrained programming method

This paper presents a stochastic optimization model to determine the optimal number of acres of hay a farm should harvest for their own horses’ consumption, as well as how much hay to purchase and sell to maximize the total profit of the farm. This research is motivated by horse farmers who must make yearly decisions concerning the management of feeding horses. These decisions are affected by the cost to grow their own hay, the cost to buy hay, the cost associated with selling hay, and the stochastic nature of crop yield due to different weather conditions. The uncertainty of weather conditions is included in the mathematical model by including random variables in the model constraints. Optimal policies are obtained for a real world case study provided by a Kentucky horse farmer by applying chance constrained programming method. A sensitivity analysis is performed to show the effectiveness of the approach.     

The teaching of dermatology in veterinary education in North America (2002)

The purpose of this study was to collect and report the current quantity and content of dermatology taught in the nonclinical and clinical curricula of North American veterinary colleges. This is the first published record of this information and was gathered from 29/30 colleges. Half of the respondents of the questionnaire thought that veterinary students currently receive sufficient didactic dermatology course work. A separate didactic dermatology course is required at 16/29 colleges, which provides a mean of 31.31 instructional units. Twenty-four of 29 veterinary colleges offer a separate clinical dermatology rotation. Thirteen schools report that students who desire a clinical rotation through dermatology usually attain it. However, it is only required for graduation in seven colleges. This report serves as a tool for veterinary schools assessing their existing curriculum and allows them to compare the education they provide in this specialty with that of other colleges.     

Tomato infectious chlorosis virus — a new clostero-like virus transmitted byTrialeurodes vaporariorum

A previously undescribed virus disease of tomato, other crops and weed hosts was found in California. Affected tomato plants exhibited interveinal yellowing, necrosis and severe yield losses. Leaf dips and purified preparations contained closterovirus-like long flexuous, filamentous particles approximately 12×850–900 nm. The virus, designated as tomato infectious chlorosis virus (TICV), is transmitted in a semipersistent manner by the greenhouse whitefly,Trialeurodes vaporariorum. The host range of the virus is moderate (26 species in 8 plant families) but includes some important crops and ornamental species including tomato, (Lycopersicon esculentum), tomatillo (Physalis ixocarpa), potato (Solanum tuberosum), artichoke (Cynara scolymus), lettuce (Lactuca sativa) and petunia (Petunia hybrida). The virus has been found in a number of different locations in California and has a number of potential vehicles of movement including greenhouse grown ornamentals, tomato transplants, artichoke cuttings and potato seed. The virus has the potential to spread to other growing regions with resident populations of the greenhouse whitefly. The host range, particle size, insect transmission, and serology clearly distinguish TICV from previously described viruses.     

Associations between canine benign and malignant neoplasms

Associations between benign and malignant neoplasms of the dog were quantitatively evaluated. Using histologically confirmed submissions and population-based methodology, canine benign tumors were significantly associated with both the unordered and subsequent development of additional distinct malignancies in the same dogs. A detailed examination of the methods indicated that these results are not likely due to methodologic artifact. The implication is that benign and malignant tumor development are associated and that the occurence of a benign neoplasm is an indicator of a parallel predisposition to malignancy.     

Survey of Mycobacterium avium subspecies paratuberculosis serological status in beef herds on community pastures in Saskatchewan

Johne's disease is a well recognized problem in dairy herds. Relatively little information is available on either the prevalence or the control of Johne's disease in commercial cow-calf operations. In the fall of 1999, blood samples were collected during pregnancy testing from cows on community pastures in Saskatchewan. Sera from these cows were analyzed using a commercial ELISA for antibodies to Mycoplasma avium subspecies paratuberculosis. All cows from each herd examined at the community pastures were sampled. Of the 1799 samples tested, 15 had sample to positive (S/P) ratios greater than 0.25 and were considered positive (apparent sample prevalence, 0.8%; 95% CI, 0.4% to 1.5%). If we assume test sensitivity of 25% and specificity of 98% as recommended by the National Johne's Working Group, the true sample prevalence is not significantly different from 0.0%. The ELISA S/P results for the antibody test-positive animals ranged from 0.27 to 2.5. If a herd was classified as positive based on one test-positive animal, the average herd apparent prevalence was 15.2% (95% CI, 7.1% to 28.6%). If the potential for false-positive results was considered with 2 or more positive animals being required for positive herd status, the herd prevalence was 3.0% (95% CI, 0.4% to 13.4%). Because of the very low prevalence in cow-calf herds, future research to identify risk factors and control points should target problem herds and utilize a case-control study design.     

Synthesis and herbicidal activity of phenyl-substituted benzoylpyrazoles

A novel series of substituted 3-phenyl benzoylpyrazoles were prepared and tested as potential grass herbicides. The targeted materials were prepared by three newly developed synthetic routes, which allowed a comprehensive study of the SAR (structure-activity relationships) of this series. The best combination of grass weed activity (Avena fatua L, Setaria viridis (L) Beauv and Alopecurus myosuroides Huds) and wheat selectivity was obtained with an alkoxy group in the 4-position of the phenyl ring. Activity was further enhanced by the presence of tert-butyl on the pyrazole and a methyl group at the C-2 position of the benzoyl moiety. The alkoxy-substituted 3-phenylbenzoylpyrazoles are a novel class of herbicides with potential utility for control of important grass weeds in cereals.