Flow visualization studies of blowing from the tip of a swept wing

Flow visualization studies of blowing from the tip of a swept wing were conducted in the Langley 16- by 24-inch water tunnel. Four wing tips, each with two independent blowing slots, were tested. The two slots were located one behind the other in the chordwise direction. The wing tips were designed to vary systematically the jet length, the jet in-plane exhaust direction (sweep), and the jet out-of-plane exhaust direction (anhedral). Each blowing slot was tested separately at two angles of attack and at four ratios of jet to free stream velocity ratios. Limited tests were conducted with blowing from both slots simultaneously. Blowing from the tip inhibited inboard spanwise flow on the upper wing surface near the tip. The jet path moved farther away from the tip with increasing jet to free stream velocity ratio and moved closer to the tip with increasing angle of attack

South Platte River Basin

Presented at Competing interests in water resources - searching for consensus: proceedings from the USCID water management conference held on December 5-7, 1996 in Las Vegas, Nevada.Includes bibliographical references.The potential of demand management as a water management tool in the South Platte River basin is limited by a lack of information regarding existing irrigation practices. A study was conducted to obtain information regarding irrigation water use practices in the basin, to determine the frequency of adoption of water conservation practices, and to relate the frequency of adoption of water conserving measures to various demographic factors. The results were based on 285 responses to a voluntary survey sent to a random sample of 1000 irrigators in eight counties within the basin during the winter of 1995. The survey sought information on farming practices, the adoption of water conservation practices, and grower characteristics. Although disincentives for irrigation water conservation appeared to be significant, the results indicated a high rate of adoption. Seventy-four percent of the survey respondents had adopted some type of water conservation measure on their farms. Adoption of various irrigation water conservation practices was associated most frequently with farm size, but factors such as method of irrigation, water source, knowledge of water law, and level of education were also associated with adoption of one or more conservation measures. Respondents indicated that the primary incentive for adopting water conservation measures was "water conservation." The typical reason for conserving water was to improve existing operations. This suggests that in many instances conservation is being used as a method of extending existing supplies on farms operating under water-short decrees

Proceedings of the 10th Annual Meeting, Southern Soybean Disease Workers (March 15-17, 1983, Houston, Texas): Significance of Soybean Diseases

Contents 1983 Southern Soybean Disease Workers Officers 1983 Southern Soybean Disease Workers Program Committee Committee Chairmen General session Presidentiial address. W Winner Soybean Research Needs and the American Soybean Association. KJ Smith American Soybean Association Pesticide Assessment in the Administrative Hearing: An Educational Guide for the Agricultural Scientist. MT Olexa and AH Daniels Soybean Disease Loss Estimate. E Koldenhoven The influence of cultural practices on disease incidence. JG Kantzes presiding The Relationship Between Chloride Uptake and Leaf Scorch of Soybeans. MB Parker, TP Gaines, and GJ Gascho Effect of No-tillage on Fusarium Blight of Soybean on Delmarva. B Carroll Effect of No-tillage on Severity of Losses from Soybean Cyst Nematode and Foliar Diseases. AY Chambers and TC McCutchen Soybean nematodes. WS Hough presiding Standardized Nematicide Research Report. A Wrather Research on the Effects of Ectoparasitic Nematodes on Soybean Yields. EC McGawley Relationship of Numbers of the Soybean Cyst Nematode and Soybean Crop Response in North Carolina. D Schmitt Level of Resistance to Cyst Nematodes in Derived Lines of Soybeans. SC Anand and CR Shumway Reduction of Soybean Cyst Nematodes Females by Furadan. AJ Howard Effect of Trifluralin (Treflan) on Soybean Cyst Nematode. RD Riggs and LR Oliver Graduate student presentations. D Schmitt presiding Effect of Three Densities of Three Meloidogyne spp. on Soybean Growth in North Florida. CH Opperman The Effects of Pratylenchus brachyurus on Yield Components of Soybeans. FR Koenning Pod and Stem Infection by Phomopsis sp. during Soybean Seed Development and Maturation. JR Hicks, LJ Tomes, and DM TeKrony New developments. G Rich, presiding Label Amendments for Furadan in Soybeans. WS Hough Summary of Super Tin 41 for Performance on Soybeans for Foliar Disease Control. EF Koldenhoven Sudden Death Syndrome of Soybean: A Disease of Unknown Etiology. M Hirrel Soybean, seed, seedling and soil-borne diseases. J Shriver presiding Standardized Seed Treatment Research Report. MC McDaniel Factors Affecting Survival and Density of Macrophomina in Soil. T Wyllie Epidemiology and Control of Soybean Seed Diseases. D McGee Evaluation for Resistance to Seed Diseases. JP Ross Foliar, pod and stem diseases of soybeans. Mel Newman presiding Summary of Regional Foliar Fungicide Treatments. AY Chambers and MA Newman Disease Awareness Research Report and Data from Compromise Point System. R Smith The Effect of Triphenyltin Hydroxide on Disease and Insect Control of Soybeans. G Whitney Stem Canker in Tennessee: The Influence of Varieties, Foliar Sprays and Planting Dates. AY Chambers Stem Canker in Alabama: The Effect of Varieties and Foliar Sprays. P Backman, M Crawford, and W Gazaway Stem Canker in Mississippi: Varietal Response and Isolate Variation. B Moore Isolation and Identification Techniques for Diaporthe phaseolorum var. caulivora. MA Crawford and PA Backman Treasurer\u27s report. D Smit

Tree-Ring Dates for the Maximum Little Ice Age Advance of Kaskawulsh Glacier, St. Elias Mountains, Canada

A dendroglaciological study at Kaskawulsh Glacier provides the first calendar dating of a Little Ice Age glacier advance in the northeast St. Elias Mountains of Yukon Territory. Ring series from white spruce trees, Picea glauca (Moench) Voss, that had been sheared, tilted, and killed by deposition of till at the glacier’s terminal moraine were cross-dated with a millennium-length ring-width chronology developed at a site near the south end of Kluane Lake, about 25 km north of the glacier forefield. Six cross-dated samples from two sites at Kaskawulsh Glacier suggest that the north lobe of the glacier reached its greatest Holocene extent in the mid-1750s. Additional limited data suggest that the east lobe may have reached its maximum extent somewhat earlier (ca. 1717). This chronology of Little Ice Age activity of Kaskawulsh Glacier is consistent with well-dated glacier chronologies from adjacent mountain ranges in coastal and interior Alaska. The results also demonstrate the potential to derive calendar dates from subfossil wood in the St. Elias Mountains that hitherto had been dated only with much lower precision, using radiocarbon techniques.L’étude dendroglaciologique du glacier Kaskawulsh fournit la première datation de calendrier de l’avancée glaciaire du petit âge glaciaire, dans le nord-est des montagnes St. Elias, territoire du Yukon. Les séries de cernes d’épinettes blanches, Picea glauca (Moench) Voss, qui avaient été abattues, inclinées et tuées par le dépôt de till à la moraine terminale du glacier, ont été contre-datées à l’aide d’une chronologie millénaire de largeur des cernes mise au point à un emplacement situé près du côté sud du lac Kluane, à environ 25 km au nord du front du glacier. Six échantillons contre-datés provenant de deux emplacements du glacier Kaskawulsh suggèrent que le lobe nord du glacier a atteint sa plus grande étendue holocène dans le milieu des années 1750. Par ailleurs, certaines données supplémentaires suggèrent que le lobe est pourrait avoir atteint son étendue maximale un peu plus tôt (vers 1717). Cette chronologie de l’activité du petit âge glaciaire du glacier Kaskawulsh coïncide avec les chronologies bien datées des chaînes de montagnes adjacentes, sur la côte et à l’intérieur de l’Alaska. Les résultats démontrent aussi la possibilité d’établir les dates de calendrier à partir de bois subfossile dans les montagnes St. Elias qui avait été daté avec beaucoup moins de précision jusqu’ici à l’aide de techniques de datation au carbone 14

Children are important too:juvenile playgroups and maternal childcare in a foraging population, the Agta

Non-maternal carers (allomothers) are hypothesized to lighten the mother's workload, allowing for the specialized human life history including relatively short interbirth intervals and multiple dependent offspring. Here, using in-depth observational data on childcare provided to 78 Agta children (a foraging population in the northern Philippines; aged 0-6 years), we explore whether allomaternal childcare substitutes and decreases maternal childcare. We found that allomother caregiving was associated with reduced maternal childcare, but the substitutive effect varied depending on the source and type of care. Children-only playgroups consistently predicted a decrease in maternal childcare. While grandmothers were rarely available, their presence was negatively associated with maternal presence and childcare, and grandmothers performed similar childcare activities to mothers. These results underscore the importance of allomothering in reducing maternal childcare in the Agta. Our findings suggest that flexibility in childcare sources, including children-only playgroups, may have been the key to human life-history evolution. Overall, our results reinforce the necessity of a broad conceptualization of social support in human childcare. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'

Children are important too: juvenile playgroups and maternal childcare in a foraging population, the Agta

Non-maternal carers (allomothers) are hypothesized to lighten the mother's workload, allowing for the specialized human life history including relatively short interbirth intervals and multiple dependent offspring. Here, using in-depth observational data on childcare provided to 78 Agta children (a foraging population in the northern Philippines; aged 0–6 years), we explore whether allomaternal childcare substitutes and decreases maternal childcare. We found that allomother caregiving was associated with reduced maternal childcare, but the substitutive effect varied depending on the source and type of care. Children-only playgroups consistently predicted a decrease in maternal childcare. While grandmothers were rarely available, their presence was negatively associated with maternal presence and childcare, and grandmothers performed similar childcare activities to mothers. These results underscore the importance of allomothering in reducing maternal childcare in the Agta. Our findings suggest that flexibility in childcare sources, including children-only playgroups, may have been the key to human life-history evolution. Overall, our results reinforce the necessity of a broad conceptualization of social support in human childcare. This article is part of the theme issue ‘Multidisciplinary perspectives on social support and maternal–child health’

Repurposing the GNAT Fold in the Initiation of Polyketide Biosynthesis.

Natural product biosynthetic pathways are replete with enzymes repurposed for new catalytic functions. In some modular polyketide synthase (PKS) pathways, a GCN5-related N-acetyltransferase (GNAT)-like enzyme with an additional decarboxylation function initiates biosynthesis. Here, we probe two PKS GNAT-like domains for the dual activities of S-acyl transfer from coenzyme A (CoA) to an acyl carrier protein (ACP) and decarboxylation. The GphF and CurA GNAT-like domains selectively decarboxylate substrates that yield the anticipated pathway starter units. The GphF enzyme lacks detectable acyl transfer activity, and a crystal structure with an isobutyryl-CoA product analog reveals a partially occluded acyltransfer acceptor site. Further analysis indicates that the CurA GNAT-like domain also catalyzes only decarboxylation, and the initial acyl transfer is catalyzed by an unidentified enzyme. Thus, PKS GNAT-like domains are re-classified as GNAT-like decarboxylases. Two other decarboxylases, malonyl-CoA decarboxylase and EryM, reside on distant nodes of the superfamily, illustrating the adaptability of the GNAT fold

Thermodynamically based DNA strand design

We describe a new algorithm for design of strand sets, for use in DNA computations or universal microarrays. Our algorithm can design sets that satisfy any of several thermodynamic and combinatorial constraints, which aim to maximize desired hybridizations between strands and their complements, while minimizing undesired cross-hybridizations. To heuristically search for good strand sets, our algorithm uses a conflict-driven stochastic local search approach, which is known to be effective in solving comparable search problems. The PairFold program of Andronescu et al. [M. Andronescu, Z. C. Zhang and A. Condon (2005) J. Mol. Biol., 345, 987–1001; M. Andronescu, R. Aguirre-Hernandez, A. Condon, and H. Hoos (2003) Nucleic Acids Res., 31, 3416–3422.] is used to calculate the minimum free energy of hybridization between two mismatched strands. We describe new thermodynamic measures of the quality of strand sets. With respect to these measures of quality, our algorithm consistently finds, within reasonable time, sets that are significantly better than previously published sets in the literature

High Density Circumstellar Interaction in the Luminous Type IIn SN 2010jl: The first 1100 days

HST and ground based observations of the Type IIn SN 2010jl are analyzed, including photometry, spectroscopy in the ultraviolet, optical and NIR bands, 26-1128 days after first detection. At maximum the bolometric luminosity was $\sim 3\times10^{43}$ erg/s and even at 850 days exceeds $10^{42}$ erg/s. A NIR excess, dominating after 400 days, probably originates in dust in the circumstellar medium (CSM). The total radiated energy is $> 6.5\times10^{50}$ ergs, excluding the dust component. The spectral lines can be separated into one broad component due to electron scattering, and one narrow with expansion velocity $\sim 100$ km/s from the CSM. The broad component is initially symmetric around zero velocity but becomes blueshifted after $\sim 50$ days, while remaining symmetric about a shifted centroid velocity. Dust absorption in the ejecta is unlikely to explain the line shifts, and we attribute the shift instead to acceleration by the SN radiation. From the optical lines and the X-ray and dust properties, there is strong evidence for large scale asymmetries in the CSM. The ultraviolet lines indicate CNO processing in the progenitor, while the optical shows a number of narrow coronal lines excited by the X-rays. The bolometric light curve is consistent with a radiative shock in an $r^{-2}$ CSM with a mass loss rate of $\sim 0.1$ M_sun/yr. The total mass lost is $> 3$ M_sun. These properties are consistent with the SN expanding into a CSM characteristic of an LBV progenitor with a bipolar geometry. The apparent absence of nuclear processing is attributed to a CSM still opaque to electron scattering.Comment: ApJ in press. Updated and changed after referees comment