Iowa Manure Matters: Odor and Nutrient Management, Winter 2003, Vol. 6, no. 9

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Winter 2004, Vol. 7, no. 4

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Winter 2005, Vol. 8, no. 4

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Winter 2006, Vol. 9, no. 4

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Winter 2007, Vol. 10, no. 4

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Winter 2008, Vol. 11, no. 3

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Winter 2002, Vol. 5, no. 4

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Nuclear factor I-C regulates TGF-{beta}-dependent hair follicle cycling.

Skin appendages such as teeth and hair share several common signaling pathways. The nuclear factor I C (NFI-C) transcription factor has been implicated in tooth development, but a potential role in hair growth had not been assessed. In this study we found that NFI-C regulates the onset of the hair growth cycle. NFI-C(-/-) mice were delayed in the transition from the telogen to anagen phase of the hair follicle cycle after either experimental depilation or spontaneous hair loss. Lack of NFI-C resulted in delayed induction of the sonic hedgehog, Wnt5a, and Lef1 gene expression, which are key regulators of the hair follicle growth initiation. NFI-C(-/-) mice also showed elevated levels of transforming growth factor β1 (TGF-β1), an inhibitor of keratinocyte proliferation, and of the cell cycle inhibitor p21 at telogen. Reduced expression of Ki67, a marker of cell proliferation, was noted at the onset of anagen, indicating impaired activation of the hair progenitor cells. These findings implicate NFI-C in the repression of TGF-β1 signaling during telogen stage, resulting in the delay of progenitor cell proliferation and hair follicle regeneration in NFI-C-deficient mice. Taken together with prior observations, these findings also designate NFI-C as a regulator of adult progenitor cell proliferation and of postnatal tissue growth or regeneration.

Effects of usual nutrient intake and vitamin D status on markers of bone turnover in Swiss adolescents.

OBJECTIVE: To evaluate the effects of nutrient intake and vitamin D status on markers of type I collagen formation and degradation in adolescent boys and girls. DESIGN: Cross-sectional study. SETTING: Canton of Vaud, West Switzerland. SUBJECTS: A total of 92 boys and 104 girls, aged 11-16 y. Data were collected on height, weight, pubertal status (self-assessment of Tanner stage), nutrient intake (3-day dietary record) and fasting serum concentration of 25-hydroxyvitamin D (25OHD), and markers of collagen formation (P1NP) and degradation (serum C-terminal telopeptides: S-CTX). RESULTS: Tanner stage was a significant determinant of P1NP in boys and girls and S-CTX in girls. Of the nutrients examined, only the ratio of calcium to phosphorus (Ca/P) was positively associated with P1NP in boys, after adjustment for pubertal status. 25OHD decreased significantly at each Tanner stage in boys. Overall, 15% of boys and 17% of girls were identified as being vitamin D insufficient (serum 25OHD <30 nmol/l), with the highest proportion of insufficiency at Tanner stage 4-5 (29%) in boys and at Tanner stage 3 (24%) in girls. A significant association was not found between 25OHD and either bone turnover marker, nor was 25OHD insufficiency associated with higher concentrations of the bone turnover markers. CONCLUSIONS: The marked effects of puberty on bone metabolism may have obscured any possible effects of diet and vitamin D status on markers of bone metabolism. The mechanistic basis for the positive association between dietary Ca/P ratio and P1NP in boys is not clear and may be attributable to a higher Ca intake per se, a critical balance between Ca and P intake or higher dairy product consumption. A higher incidence of vitamin D insufficiency in older adolescents may reflect a more sedentary lifestyle or increased utilisation of 25OHD, and suggests that further research is needed to define their requirements. SPONSORSHIP: Nestec Ltd and The Swiss Foundation for Research in Osteoporosis.

Nutrient and light availability to white spruce seedlings in partial and clearcut harvested aspen stands

Abstract

1199-000 Soil Nutrient Mass Balance Study

Key Points: • Iowa’s exceptional agricultural productivity is dependent upon nutrient‐rich soils with high carbon and nitrogen stocks. • Soil carbon and nitrogen stocks in Iowa corn‐soybean rotations are at significant risk of long‐term decline. • Soil carbon and nitrogen stocks are a function of crop residue inputs. • Nutrient input levels that do not maximize crop yield and residue production are likely to reduce soil carbon and nitrogen stocks. • If soil carbon and nitrogen stocks decline, water quality improvements become more difficult. • Soil carbon and nitrogen balances are extremely difficult to measure, but positive balances are essential to the future of Iowa agriculture. Recommended Actions: • Accurate measurement of soil carbon and nitrogen balances is exceptionally difficult, but can be accomplished with sufficient investment and long‐term planning. • The ideal approach will include a combination of measurements from farms and experimental networks that manipulate nutrient inputs. • With proper planning and cooperation, Iowa State University and the Iowa Department of Agriculture and Land Stewardship can address the concerns raised in this report regarding the future of Iowa’s soil resource and agricultural productivity.

Impact of unusual fatty acid synthesis on futile cycling through beta-oxidation and on gene expression in transgenic plants.

Arabidopsis expressing the castor bean (Ricinus communis) oleate 12-hydroxylase or the Crepis palaestina linoleate 12-epoxygenase in developing seeds typically accumulate low levels of ricinoleic acid and vernolic acid, respectively. We have examined the presence of a futile cycle of fatty acid degradation in developing seeds using the synthesis of polyhydroxyalkanoate (PHA) from the intermediates of the peroxisomal beta-oxidation cycle. Both the quantity and monomer composition of the PHA synthesized in transgenic plants expressing the 12-epoxygenase and 12-hydroxylase in developing seeds revealed the presence of a futile cycle of degradation of the corresponding unusual fatty acids, indicating a limitation in their stable integration into lipids. The expression profile of nearly 200 genes involved in fatty acid biosynthesis and degradation has been analyzed through microarray. No significant changes in gene expression have been detected as a consequence of the activity of the 12-epoxygenase or the 12-hydroxylase in developing siliques. Similar results have also been obtained for transgenic plants expressing the Cuphea lanceolata caproyl-acyl carrier protein thioesterase and accumulating high amounts of caproic acid. Only in developing siliques of the tag1 mutant, deficient in the accumulation of triacylglycerols and shown to have a substantial futile cycling of fatty acids toward beta-oxidation, have some changes in gene expression been detected, notably the induction of the isocitrate lyase gene. These results indicate that analysis of peroxisomal PHA is a better indicator of the flux of fatty acid through beta-oxidation than the expression profile of genes involved in lipid metabolism.

Transcriptome analysis of intraspecific competition in Arabidopsis thaliana reveals organ-specific signatures related to nutrient acquisition and general stress response pathways.

ABSTRACT: BACKGROUND: Plants are sessile and therefore have to perceive and adjust to changes in their environment. The presence of neighbours leads to a competitive situation where resources and space will be limited. Complex adaptive responses to such situation are poorly understood at the molecular level. RESULTS: Using microarrays, we analysed whole-genome expression changes in Arabidopsis thaliana plants subjected to intraspecific competition. The leaf and root transcriptome was strongly altered by competition. Differentially expressed genes were enriched in genes involved in nutrient deficiency (mainly N, P, K), perception of light quality, and responses to abiotic and biotic stresses. Interestingly, performance of the generalist insect Spodoptera littoralis on densely grown plants was significantly reduced, suggesting that plants under competition display enhanced resistance to herbivory. CONCLUSIONS: This study provides a comprehensive list of genes whose expression is affected by intraspecific competition in Arabidopsis. The outcome is a unique response that involves genes related to light, nutrient deficiency, abiotic stress, and defence responses.

Nutrient-based dietary patterns and the risk of head and neck cancer: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium.

Background The association between dietary patterns and head and neck cancer has rarely been addressed. Patients and methods We used individual-level pooled data from five case-control studies (2452 cases and 5013 controls) participating in the International Head and Neck Cancer Epidemiology consortium. A posteriori dietary patterns were identified through a principal component factor analysis carried out on 24 nutrients derived from study-specific food-frequency questionnaires. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using unconditional logistic regression models on quintiles of factor scores. Results We identified three major dietary patterns named 'animal products and cereals', 'antioxidant vitamins and fiber', and 'fats'. The 'antioxidant vitamins and fiber' pattern was inversely related to oral and pharyngeal cancer (OR = 0.57, 95% CI 0.43-0.76 for the highest versus the lowest score quintile). The 'animal products and cereals' pattern was positively associated with laryngeal cancer (OR = 1.54, 95% CI 1.12-2.11), whereas the 'fats' pattern was inversely associated with oral and pharyngeal cancer (OR = 0.78, 95% CI 0.63-0.97) and positively associated with laryngeal cancer (OR = 1.69, 95% CI 1.22-2.34). Conclusions These findings suggest that diets rich in animal products, cereals, and fats are positively related to laryngeal cancer, and those rich in fruit and vegetables inversely related to oral and pharyngeal cancer.