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The conversion of land from existing uses to biofuel cultivation is expected to increase given concerns about the sustainability of fossil fuel supplies. Nonetheless, research into the environmental impacts of biofuel crops, primarily the hydrological impacts of their cultivation, is in its infancy. To investigate such issues, the response of a 1,649 km² semiarid basin to the incremental substitution of the widely discussed biofuel candidate switchgrass (Panicum virgatum L.) for native land uses was modeled using the Soil and Water Assessment Tool (SWAT). Median discharges decreased by 5.6-20.6% during the spring and by 6.4-31.2% during the summer, depending on the quantity of acreage converted. These were driven by an increased spring and summer evapotranspiration of 3.4-32.0% and 1.5-18.9%, respectively, depending on the quantity of switchgrass biomass produced. The substitution of switchgrass also resulted in larger quantities of water stress days than in baseline scenarios. The authors encourage the exploration of alternative biofuel crops in semiarid areas to mitigate such negative impacts. [ABSTRACT FROM AUTHOR]

The article offers information on the role of human resources (HR) for the success of a business. It mentions that the role of HR will alter to reflect the strategic contribution that needs to be embraced for an organization to progress. It states that the critical role of the HR professional is to make awareness of the effect of sustainability on the organization and nurture a uniform understanding within the organization concerning the aim of sustainability.

The attentions given to textual production in composition scholarship have led to a neglect of the dynamics of textual reception. Renewed acquaintance with the discipline of hermeneutics will provide scholars and instructors with a more comprehensive understanding of the relationship between interpretive processes and rhetorical strategies. Building on the work of Phelps, Mailloux, and Crusius, this article revisits Gadamer and Ricoeur, two of the more prominent scholars of modern hermeneutics, for the purpose of applying their principles to learning objectives and class assignments in college-level writing courses. [ABSTRACT FROM AUTHOR]

The article provides a critical reflection on the study of composition and rhetoric. It examines the connection between composition Studies and the humanities. The book "Arts of Living," by Kurt Spellmeyer about the state of the humanities in the academy is discussed. The article argues for balance in tendencies towards pragmatism under the context of composition studies or composition and rhetoric.

Growth and physiological performance of multipurpose tree species can be severely constrained by low phosphorus (P) availability in highly weathered soils. Limitations to plant growth are accentuated by seasonal dry periods. The overall objective of this study was to examine P fertilization and irrigation effects on survival, growth, biomass partitioning, foliar nutrients, intrinsic water-use efficiency (WUE) indexed by δ13C, Rhizobium nodulation, and carbohydrate content as an indicator of resprouting potential, of mimosa ( Albizia julibrissin Durz.), a N2-fixing tree species being tested for browse in agroforestry practices in south-central USA. In a field experiment carried out during two growing seasons near Booneville, Arkansas, USA, mimosa had a strong growth response to irrigation. The trial was arranged in a split plot design with three replications with irrigation as main plot treatment and P as sub-plot treatment. Mean total plant aboveground biomass at the end of the second growing season was 9.8 and 44.1 g plant−1 for the rainfed treatment without and with 300 mm of irrigation water, respectively. Placed P fertilization increased mean total aboveground biomass from 19 g plant−1 for the 0-P treatment to 69 g plant−1 for the treatment with 90 kg P ha−1 year−1. Similarly, irrigation consistently increased stem basal diameter, total height, survival, root, stem, foliar and total aboveground biomass, and number of nodules per plant. Phosphorus fertilization increased basal diameter, and root and stem biomass in both irrigation treatments, survival and nodulation in the rainfed treatment, and foliar and total aboveground biomass in the rainfed +300 mm irrigation treatment. There was a decrease of foliar δ13C suggesting that WUE decreased with P fertilization. In a pot experiment, seedlings were subjected to a factorial combination of two irrigation treatments and six P levels in a randomized complete block design. Irrigation increased basal diameter, root, stem, foliar and total biomass, leaf area and nodulation, whereas P fertilization (i.e., levels from 0 to 3.68 g P kg−1 soil) had similar effect in all the above variables except foliar biomass. Foliar P concentration to obtain 90% of the maximum total plant biomass (critical level) was estimated at 0.157%. Total nonstructural and water soluble carbohydrate, and starch concentrations increased non-linearly with irrigation and P addition suggesting impaired re-growth potential after defoliation of seedlings with reduced water supply and at low soil P availability. Results of this study indicated strong limitations for growth and regrowth potential of mimosa on a highly weathered soil with very low P availability and seasonal water content shortages. Placed (i.e., near the plant base) application of P appeared to be a good strategy to fertilize perennial woody plants. [ABSTRACT FROM AUTHOR]

Fungal polysaccharides and glucans, including lentinan from shiitakes, have been identified as promoting human health, and consequently, the sale of mushroom-based health products has increased significantly in recent years. Reliable methods for the quantitation of lentinan must be available if shiitakes or shiitake-derived products are to be promoted as health-promoting food. The objective of this study was to characterize two methods for the quantitation of β-glucans from aqueous extracts of shiitake mushrooms. The first method utilized ethanol precipitation and batch size exclusion chromatography to isolate a fraction enriched in lentinan, called high molecular weight polysaccharides, HMWP. Gel filtration chromatography characterization of HMWP fraction indicated that the size distribution of carbohydrates was similar to that of a lentinan standard. Analyses for total starch and glycogen, to a lesser extent, indicate these polysaccharides are less than 10% of the total carbohydrates in HMWP. These results suggest that the HMWP fraction had a high level of lentinan. The second method measured the production of glucose by enzymes that specifically hydrolyze plant β-glucans. The amount of carbohydrate detected by the enzymatic β-glucan assay was significantly less than the carbohydrate found in the HMWP fraction. The low content of β-glucan was not due to a failure of the assay's enzymes to function. In addition, no glucose was produced when a lentinan standard was subjected to the β-glucan assay. These results indicate that the carbohydrate content ofHMWPfraction was a better indicator of lentinan content of shiitakes compared to the mushroom's β-glucan content. [ABSTRACT FROM AUTHOR]

Discusses the collision between the personal beliefs of students with the discourse of the natural sciences in composition courses. Definition of personal beliefs according to scholar Patricia Sullivan; Depiction of a agonistic relationship between the discourses of science and personal belief in the films "Contact" and "The Exorcism of Emily Rose"; Appropriateness of global warming as an issue to be used in introducing students to scientific discourse.

Abstract: Patterns of biomass partitioning have been extensively studied in loblolly pine (Pinus taeda L.) plantations and natural stands, but not in silvopastoral practices, which are being promoted in southern United States. We conducted aboveground biomass harvests in 18-year-old loblolly pine growing in single-, double-, and quadruple-row configurations at 2.1m between trees in the row, and initial densities of 308, 568, and 932 treesha−1. In the double- and quadruple-row configurations, rows were 2.4m apart while alleys were 14.6m wide in all configurations. Trees were felled from single, double (east and west orientations) and, the exterior east and one of the interior (trees identified as QR2) quadruple rows, and separated into bole, branches, twigs (<2cm in diameter), and foliage. In total, 60 trees within the 25–29cm DBH class were sampled (five configurations×three trees per row×two pruning regimes×two replicates). Averaged across pruning regimes, absolute total aboveground biomass per tree ranged from 366kg in single-row trees to 231kg in QR2-trees while bole biomass varied from 185kg in single-row trees to 143kg in QR2-trees. Configuration affected relative biomass partitioning to boles (P <0.05), which ranged, on an average, from 60% of total tree biomass in quadruple rows to 52% in single rows, branch (P <0.05), which varied from 30% in single rows to 24% in quadruple rows, and foliage (P <0.001), which ranged from 12% in single rows to 8% in quadruple rows. Bole DBH and available ground space per tree (as covariates) did not affect biomass partitioning as neither did pruning, although pruning markedly improved log quality. Basal areas in single-, double-, and quadruple-row configurations in the silvopasture were 11, 19, and 34% greater than the projected basal areas for adjacent loblolly pine plots with similar stand density. [Copyright &y& Elsevier]

Acidic soils tend to limit the nodulation of forage legumes and roothairs are important for Rhizobia binding and the initiation of nodule formation. This study examined the effects of Ca, pH, and Al on the length of roothairs in nutrient solutions and soils with white clover (Trifolium repens L., cultivar Huia) seedlings. The lengths of roothairs of 1- to 2 -d-old seedlings was not affected by increases in solution Al up to 24 μM in nutrient solution experiments, but showed a pronounced optimum at a predicted root surface pH of 3.8. Roothair lengths of white clover seedlings 2 to 10 d after planting were also assessed in a Gilpin series silt loam collected from New, WV, and amended with various levels of lime. Soils ranged in pH from 46 to 5.3 and soil base saturation of Al from 46 to 8%. No significant differences in roothair lengths as a function of soil pH and/or soil available Al were observed. Previous results conducted under similar experimental conditions demonstrated that soil pH-soil-available Al adversely affected on root elongation and nodulation. When results from this and the previous reports are considered together, the combined results suggest that root elongation and nodulation were more sensitive than roothair length to acidic soil conditions. [ABSTRACT FROM AUTHOR]

Methods for the simultaneous measurement of vacuolar and cytoplasmic pH in plant tissues currently have significant limitations. This study demonstrates the usefulness of methyl difluoro alanine (F2ALA) and methyl trifluoro alanine (F3ALA) with in-vivo19F NMR spectroscopy to measure vacuolar and cytoplasmic pH in maize root tissue. The pH dependence of the chemical shift of F2ALA and F3ALA is greater than either the commonly used31P NMR signal of inorganic phosphate or the13C NMR signals of trans-aconitic acid, which is also found in some plant cells. F2ALA and F3ALA were also able to detect changes over a greater range of pH. When maize root tissue was incubated in the presence of 0.35 mmF2ALA or F3ALA, these accumulated to significant concentrations in two compartments of different pH with no significant effect on growth rate of root tips. The time course of accumulation and the pH of the two compartments were consistent with one being the cytoplasm and the other the vacuole. The chemical shift of both C2 of trans-aconitic acid and vacuolar F3ALA indicated that the mean vacuolar pH of maize root cells was 4.6 and that the pH gradient across the tonoplast membrane was about 2.8 units. Under a variety of conditions, there was considerable heterogeneity in the pH of the vacuoles in maize root tissue as indicated by the peak width of the signal from F3ALA. The significance of these values is discussed in terms of the bioenergetics of proton transport across the tonoplast membrane in vivo. [ABSTRACT FROM AUTHOR]