INFLUENCE OF GENOTYPE, PROTEIN-CALORIE RESTRICTION AND THEIR INTERACTION UPON RSV-INDUCED TUMORS IN CHICKENS

The major objective of this research was to investigate the relative contribution of genetics, nutritional restriction and the genetics by nutritional restriction interaction upon Rous sarcoma virus (RSV)-induced tumor development in chickens. Two genetic systems were used. The first involved an inbred line and a noninbred line of chickens. The second utilized F2 generation progeny from a cross of lines 6-1 and 15-1, highly inbred lines of White Leghorns from the Regional Poultry Research Laboratory of the United States Department of Agriculture at East Lansing, Michigan. These chickens had been blood typed for allcantigens coded for by genes of the major histocompatibility complex and were of two geneotypes--B2B2 and B5B5. Four-week-old chickens were either full-fed or restricted to 60% of the feed consumed by full-fed chickens of the same age. Two weeks after being placed on experimental rations, chickens were inoculated with RSV-1. Tumors were scored subjectively for size several times during a 10 week period. Forty percent nutritional restriction delayed the appearance of tumor and reduced tumor size at 2 and 3 weeks post-inoculation (PI). B genotype profoundly influenced tumor size. E2B2 chickens had smaller tumors between 3 and 10 weeks PI than did corresponding B5B5 chickens. Similar to 40% restriction, 50% restriction delayed tumor formation and retarded early tumor growth. Nutritional restriction may be retarding initial tumor growth by two possible mechanisms: (1)nutritional deprivation may inhibit antibody production, including blocking antibody, and enhance cell-mediated immunity, resulting in inhibited tumor growth, or (2)rapid tumor growth is restricted due to a limited supply of nutrients to the cancer cells. Forty percent restriction did not exert an effect on immunocompetence based upon antibody production to sheep erythrocytes and phytohemaglutinin-stimulated lymphocyte blastogenesis as measures of cell-mediated and humoral immunity, respectively. Thus a limited supply of nutrients may retard initial tumor growth

History of mathematics in teachers' education: Motivation for and of Discussion Group 2

International audienceDiscussion Group 2 (DG 2), in a sequence of two one-hour sessions, revisits the discussion about the role of history of mathematics in teachers' education – both for pre-service teachers and currently practicing teachers. Activities of DG 2 include a discussion of examples from the literature that propose benefits for teachers and their students when history of mathematics is utilized to teach and learn mathematics. Participants will also share experiences from their own contexts. In particular, DG 2 will draw upon concrete examples from university courses, professional development programs, and projects, and when possible, the observed and/or documented benefits derived from the use of history of mathematics resulting from these examples. Finally, participants will discuss specific tasks or activities that may serve as examples for contexts that do not currently possess a strong history of mathematics dimension within mathematics teacher education programs, or which may provide new examples for those who do.

ENGAGE: Guided Activity-Based Gaming in Neurorehabilitation after Stroke: A Pilot Study

Introduction. Stroke is a leading cause of disability in healthy adults. The purpose of this pilot study was to assess the feasibility and outcomes of a novel video gaming repetitive practice paradigm, (ENGAGE) enhanced neurorehabilitation: guided activity-based gaming exercise. Methods. Sixteen individuals at least three months after stroke served as participants. All participants received concurrent outpatient therapy or took part in a stroke exercise class and completed at least 500 minutes of gaming. Primary baseline and posttest outcome measures included the Wolf motor function test (WMFT) and the Fugl-Meyer assessment (FMA). ENGAGE uses a game selection algorithm providing focused, graded activity-based repetitive practice that is highly individualized and directed. The Wilcoxon signed ranks test was used to determine statistical significance. Results. There were improvements in the WMFT (=0.003) and the FMA (=0.002) that exceeded established values of minimal clinically important difference. Conclusions. ENGAGE was feasible and an effective adjunct to concurrent therapy after stroke

Mapping of Photoperiod-induced Growth Cessation in the Wild Grape Vitis riparia

In grapevines (Vitis spp.), the timing of growth cessation in the fall is an important aspect of adaptation and a key objective in breeding new grape cultivars suitable for continental climates. Growth cessation is a complex biological process that is initiated by environmental cues such as daylength and temperature, as well as water and nutrient availability. The genetic control of growth cessation in grapevines was studied by mapping quantitative trait loci (QTL) in a hybrid grape population. An F2 mapping population was developed by selfing a single F1 plant derived from a cross between an accession of the North American species Vitis riparia and the Vitis hybrid wine cultivar Seyval (Seyve-Villard 5–276). A linkage map was constructed using 115 simple sequence repeat (SSR) markers and six candidate genes in a population of 119 F2 progeny. The markers provided coverage of the 19 Vitis linkage groups with an average distance between markers of 8.4 cM. The critical photoperiod for growth cessation in lateral buds for the parents and F2 progeny was determined in a replicated field trial in 2001 and 2002 and under controlled photoperiod treatments in a greenhouse in 2002, 2003, and 2004. QTL analysis using composite interval mapping identified a single major QTL in the field and greenhouse trials. However, the field and greenhouse QTL mapped to different linkage groups in the two different environments, suggesting the presence of additional, nonphotoperiodic cues for induction of growth cessation in the field. In the greenhouse, where noninducing temperatures were maintained, a QTL on linkage group (LG) 13 explained 80.0% to 96.6% of the phenotypic variance of critical photoperiod for growth cessation. In the field, where vines experienced natural fluctuations in temperature and rainfall in addition to the naturally decreasing photoperiod, a QTL on LG 11 explained 85.4% to 94.3% of phenotypic variance

Use of Ultrasound Measurements to Direct Laparoscopic Pyloromyotomy in Infants

Preoperative ultrasound measurement of pyloric length to determine laparoscopic pyloromyotomy appears to minimize the risk of incomplete pyloromyotomy

Identification and characterization of the intracellular poly-3-hydroxybutyrate depolymerase enzyme PhaZ of Sinorhizobium meliloti

<p>Abstract</p> <p>Background</p> <p><it>S. meliloti </it>forms indeterminate nodules on the roots of its host plant alfalfa (<it>Medicago sativa</it>). Bacteroids of indeterminate nodules are terminally differentiated and, unlike their non-terminally differentiated counterparts in determinate nodules, do not accumulate large quantities of Poly-3-hydroxybutyrate (PHB) during symbiosis. PhaZ is in intracellular PHB depolymerase; it represents the first enzyme in the degradative arm of the PHB cycle in <it>S. meliloti </it>and is the only enzyme in this half of the PHB cycle that remains uncharacterized.</p> <p>Results</p> <p>The <it>S. meliloti phaZ </it>gene was identified by <it>in silico </it>analysis, the ORF was cloned, and a <it>S. meliloti phaZ </it>mutant was constructed. This mutant exhibited increased PHB accumulation during free-living growth, even when grown under non-PHB-inducing conditions. The <it>phaZ </it>mutant demonstrated no reduction in symbiotic capacity; interestingly, analysis of the bacteroids showed that this mutant also accumulated PHB during symbiosis. This mutant also exhibited a decreased capacity to tolerate long-term carbon starvation, comparable to that of other PHB cycle mutants. In contrast to other PHB cycle mutants, the <it>S. meliloti phaZ </it>mutant did not exhibit any decrease in rhizosphere competitiveness; however, this mutant did exhibit a significant increase in succinoglycan biosynthesis.</p> <p>Conclusions</p> <p><it>S. meliloti </it>bacteroids retain the capacity to synthesize PHB during symbiosis; interestingly, accumulation does not occur at the expense of symbiotic performance. <it>phaZ </it>mutants are not compromised in their capacity to compete for nodulation in the rhizosphere, perhaps due to increased succinoglycan production resulting from upregulation of the succinoglycan biosynthetic pathway. The reduced survival capacity of free-living cells unable to access their accumulated stores of PHB suggests that PHB is a crucial metabolite under adverse conditions.</p

A Comparative Analysis of Methylome Profiles of Campylobacter jejuni Sheep Abortion Isolate and Gastroenteric Strains Using PacBio Data

Campylobacter jejuni is a leading cause of human gastrointestinal disease and small ruminant abortions in the United States. The recent emergence of a highly virulent, tetracycline-resistant C. jejuni subsp. jejunisheep abortion clone (clone SA) in the United States, and that strain\u27s association with human disease, has resulted in a heightened awareness of the zoonotic potential of this organism. Pacific Biosciences\u27 Single Molecule, Real-Time sequencing technology was used to explore the variation in the genome-wide methylation patterns of the abortifacient clone SA (IA3902) and phenotypically distinct gastrointestinal-specific C. jejuni strains (NCTC 11168 and 81-176). Several notable differences were discovered that distinguished the methylome of IA3902 from that of 11168 and 81-176: identification of motifs novel to IA3902, genome-specific hypo- and hypermethylated regions, strain level variability in genes methylated, and differences in the types of methylation motifs present in each strain. These observations suggest a possible role of methylation in the contrasting disease presentations of these three C. jejuni strains. In addition, the methylation profiles between IA3902 and a luxS mutant were explored to determine if variations in methylation patterns could be identified that might explain the role of LuxS-dependent methyl recycling in IA3902 abortifacient potential

Comparison of methods for calibrating AVIRIS data to ground reflectance

We are comparing three basic methods of calibrating AVIRIS data to ground reflectance: (1) atmospheric radiative transfer models with the solar flux can be used to calibrate AVIRIS radiance data (Specific methods include the University of Colorado CSES ARP and ATREM algorithms); (2) Robert Green's modified MODTRAN and AVIRIS radiance model (This method is similar to 1 but differs in that the solar radiance is bypassed, so any errors in the solar flux are canceled, too); and (3) ground calibration using known sites in the AVIRIS scene. We are using 1992AVIRIS data over Cuprite, Nevada, and Blackhawk Island, Wisconsin, as our test scenes. Both these sites have extensive field measurements. The Cuprite site had a very clear atmosphere, thus path radiance was dominated by Rayleigh scattering with little or no flux beyond 1 micron. The Blackhawk site has more aerosols, with significant path radiance flux beyond 2 micron