VALIDATION OF A NOVEL TECHNIQUE FOR CREATING SIMULATED RADIOGRAPHS USING COMPUTED TOMOGRAPHY DATASETS

Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug‐in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube‐patient‐detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse. Simulated radiographs of different body parts (n = 9) were produced using different angles to mimic conventional projections, before actual digital radiographs were obtained using the same projections. These studies (n = 18) were then submitted to 10 board‐certified radiologists who were asked to score visualization of anatomical landmarks, depiction of patient positioning, realism of distortion/magnification, and image quality. No significant differences between simulated and actual radiographs were found for anatomic structure visualization and patient positioning in the majority of body parts. For the assessment of radiographic realism, no significant differences were found between simulated and digital radiographs for canine pelvis, equine tarsus, and feline abdomen body parts. Overall, image quality and contrast resolution of simulated radiographs were considered satisfactory. Findings from the current study indicated that radiographs simulated using this new technique are comparable to actual digital radiographs. Further studies are needed to apply this technique in developing interactive tools for teaching radiographic anatomy and the effects of varying patient and tube positioning.     

Using a multifaceted approach to reveal avian community responses to natural and anthropogenic effects in a fragmented Southern Mistbelt Forest system,South Africa

Landscape Ecology - Forest loss and fragmentation are major drivers of biodiversity decline globally. However, with the widely recognised notion that biodiversity is multifaceted, few studies have...     

Effects of dietary cellobiose on the intestinal microbiota and excretion of nitrogen metabolites in healthy adult dogs

In order to evaluate the potential prebiotic effects of cellobiose, 10 healthy adult research beagle dogs received a complete diet containing 0, 0.5 and 1 g cellobiose/kg bodyweight (BW)/day. At the end of each feeding period, faeces, urine and blood of the dogs were collected. The results demonstrated a significant increase of faecal lactate concentrations, indicating a bacterial fermentation of cellobiose in the canine intestine. Along with this, a dose-dependent linear increase of the relative abundance of Lactobacillaceae in the faeces of the dogs was observed (p = 0.014). In addition, a dose-dependent increase (p < 0.05) of Alloprevotella, Bacteroides and Prevotella, and a linear decrease for unidentified Lachnospiraceae (p = 0.011) was observed when cellobiose was added to the diet, although the relative abundance of these genera was low (<1%) among all groups. The faecal pH was not affected by dietary cellobiose. Cellobiose seemed to modulate the excretion of nitrogen metabolites, as lower concentrations of phenol (p = 0.034) and 4-ethylphenol (p = 0.002) in the plasma of the dogs were measured during the supplementation periods. Urinary phenols and indoles, however, were not affected by the dietary supplementation of cellobiose. In conclusion, cellobiose seems to be fermented by the intestinal microbiota of dogs. Although no effect on the faecal pH was detected, the observed increase of microbial lactate production might lower the pH in the large intestine and consecutively modulate the intestinal absorption of nitrogen metabolites. Also, the observed changes of some bacterial genera might have been mediated by increased intestinal lactate concentrations or a higher relative abundance of lactobacilli. Whether these results could be considered as a prebiotic effect and used as a dietetic strategy in diseased animals to improve gut function or hepatic and renal nitrogen metabolism should be evaluated in future studies.     

Aroma biosynthesis in strawberry: s-adenosylmethionine:furaneol o-methyltransferase activity in ripening fruits

Among the most important volatile compounds in the aroma of strawberries are 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol) and its methoxy derivative (methoxyfuraneol, mesifuran). Three strawberry varieties, Malach, Tamar, and Yael, were assessed for total volatiles, Furaneol, and methoxyfuraneol. The content of these compounds sharply increased during fruit ripening, with maximum values at the ripe stage. An enzymatic activity that transfers a methyl group from S-adenosylmethionine (SAM) to Furaneol sharply increases during ripening of strawberry fruits. The in vitro generated methoxyfuraneol was identified by radio-TLC and GC-MS. The partially purified enzyme had a native molecular mass of approximately 80 kDa, with optimum activity at pH 8.5 and 37 degrees C. A high apparent K(m) of 5 mM was calculated for Furaneol, whereas this enzyme preparation apparently accepted as substrates other o-dihydroxyphenol derivatives (such as catechol, caffeic acid, and protocatechuic aldehyde) with much higher affinities (K(m) approximately 105, 130, and 20 microM, respectively). A K(m) for SAM was found to be approximately 5 microM, regardless of the acceptor used. Substrates that contained a phenolic group with only one OH group, such as p-coumaric and trans-ferulic acid, as well as trans-anol and coniferyl alcohol, were apparently not accepted by this activity. It is suggested that Furaneol methylation is mediated by an O-methyltransferase activity and that this activity increases during fruit ripening.     

Genetic diversity of cowpea [<Emphasis Type="Italic">Vigna unguiculata</Emphasis> (L.) Walp.] in four West African and USA breeding programs as determined by AFLP analysis

Cowpea is an important grain legume and hay crop of many tropical and subtropical regions, especially in the dry savanna region of West Africa. The cowpea gene pool may be narrow because of a genetic bottleneck during domestication. Genetic variation within specific breeding programs may be further restricted due to breeding methods, ‘founder effects’ and limited exchange of germplasm between breeding programs. Genetic relationships among 60 advanced breeding lines from six breeding programs in West Africa and USA, and 27 landrace accessions from Africa, Asia, and South America were examined using amplified fragment length polymorphism (AFLP) markers with six near infrared fluorescence labeled EcoRI + 3/1bases/MseI + 3/1bases primer sets. A total of 382 bands were scored among the accessions with 207 polymorphic bands (54.2%). Despite a diverse origin, the 87 cowpea accessions shared a minimum 86% genetic similarity. Principal coordinates analysis showed clustering of breeding lines by program origin, indicating lack of genetic diversity compared to potential diversity. Accessions from Asia and the Americas overlapped and were distinct from West African breeding lines, indicating that germplasm from Asia and the Americas have common origins outside West Africa. US and Asian breeding programs could increase genetic variability in their programs substantially by incorporating germplasm from West Africa, while national programs in West Africa should consider introgression of Asian germplasm and germplasm from other parts of Africa into their programs to ensure long-term gains from selection.     

Community Partners for Healthy Farming Intervention Research

The purpose of the Community Partners for Healthy Farming Intervention Research (CPHF-IR) program is to implement and evaluate existing or new interventions for reduction of agriculture-related injuries, hazards, and illnesses. Objectives include the development of active partnerships between experienced researchers, communities, workers, managers, agricultural organizations, agribusinesses, and other stakeholders. Specific intervention projects were selected by the competitive review process in response to a request for proposals. The second series of projects (funded 2000-2003) targeted: improved ergonomics for handling grapes (CA) and for small-scale berry growers (WI, IA, MI, MN), engineering controls (KY, VA, SC) and training (IN) related to tractors, private-sector financial incentives for safety (IA, NE), and reducing eye injuries in Latino farmworkers (IL, MI, FL). Partners have provided their unique resources for accessing the target population, planning, implementation, dissemination, and evaluation. They have produced useful engineering controls, educational and motivational tools, and helped build infrastructure for promoting agricultural health as essential to sustainable agriculture. Additional outcomes have included: increased interest among participants in collaborating in further research, the feasibility of Latino lay health advisors as active partners in research, and the value of process evaluation of a partnership to enhance intervention sustainability. NIOSH is utilizing the model created for Simple Solutions: Ergonomics for Farm Workers, a document related to earlier CPHF-IR projects, for a comparable document for construction in both English and Spanish. This program has confirmed that such partnerships can produce not only sustainable interventions but also products and models with the potential to expand farther geographically than originally anticipated and even into other sectors, e.g., for primary prevention among healthcare workers and adolescents, and to introduce public health in social studies and language classes.     

Tillage and mulching effects on physical properties of a tropical Alfisol

The mechanization of field operations like seeding, spraying and harvesting in continuous zero-tillage may lead to a severe compaction of the surface layer of coarse textured tropical soils, especially when mulch is sparse or missing. Therefore, a 2 year (1982–1984) field experiment was initiated on an Alfisol in Nigeria to study the effect of tillage, mechanization and mulch on soil structure and physical properties. Three zero-tillage treatments and a plough treatment were compared. The disk-plough and one of the no-till treatments were highly mechanized: all the field work was performed with tractors and machines, and consisted of secondary bush clearing, crop cultivation and harvest. On the other two no-till treatments, the impact of machine load was reduced, wither by hand harvesting or by performing all field operations manually. These four tillage-traffic systems were either treated with mulch or left unmulched. There were four growing seasons, with maize (Zea mays L.) as a test crop.

After 2 years of zero-tillage the bulk density (BD) and penetration resistance (PR) were significantly greater on plots with high mechanization compared with hand treated plots. Plots with hand harvest but otherwise mechanized were in between. Because of the hard-setting nature of the soil, the plougheed plots with and without mulch exhibited a dramatic change in PR and BD during the season. On no-till the infiltration transmissivity (A) was greater and BD and PR were less in the mulched compared with the unmulched treatments.

The gravel content of the topsoil was negatively correlated with BD and positively correlated with A. Geostatistical analysis revealed that within the experimental area there was a similar spatial distribution of gravel content and A after the first season. Because of the superimposing effect of gravel on BD, which cannot be accounted for by considering the gravel content per se, BD was adjusted by means of covariance analysis for evaluation of the treatment effects already mentioned.

It was concluded that mechanization of a no-till system on sandy Alfisols may only be successful in the long run if appropriate measures like mulching, crop rotation and fallow systems are applied to regenerate soil structure and to enhance macroporosity.     

Nitrogen leaching losses under crops fertilized with biowaste compost compared with mineral fertilization

The effect of compost fertilization compared with mineral fertilization on N leaching to the groundwater was investigated in six plots of a long‐term field experiment and a lysimeter station on a Molli‐gleyic Fluvisol (WRB) near Vienna, Austria. The plots investigated included two treatments with compost fertilization (16 and 23 t ha^–1 y^–1, respectively, on average of 11 y), two treatments with mineral N fertilization (41 and 56 kg N ha^–1 y^–1, respectively), and two treatments with combined fertilization (9 t compost + 56 kg N ha^–1 y^–1 and 23 t compost + 22 kg N ha^–1 y^–1, respectively). Nitrogen leaching to the groundwater as determined using ceramic suction cups was not increased after 11 y of compost fertilization with higher amounts than used in practical farming (23 t ha^–1 y^–1, corresponding to an annual input of 205 kg N_tot ha^–1) as compared to mineral fertilization under the conditions of the experiment. Even intensive N mineralization during a 4‐month period of bare fallow did not cause pronounced differences between the fertilization treatments. The results suggest that in the pannonic climate, compost fertilization does not pose a risk for groundwater eutrophication on the medium term.