bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fate and Transport of Phosphorus in Turfgrass Ecosystems
Authors: Soldat Douglas J. , Petrovic A. Martin
Published: November 2008

Phosphorus losses from turfgrass areas are perceived to contribute to water quality problems, yet a comprehensive review of P fate in turfgrass ecosystems is lacking. According to available data in the literature, phosphorus fertilizer inputs (2–10 kg ha−1) slightly exceed the estimated outputs of phosphorus in clippings (0.4–7.5 kg ha−1). Sediment losses from turf areas are negligible, generally limited to establishment, but runoff and leaching losses of P vary from inconsequential to severe depending on rate, source, and timing of fertilizer application. Soil properties were found to have a larger effect on runoff volume than vegetative properties. Highest runoff and leaching losses of P occurred when rainfall occurred or was simulated shortly after P fertilizer application. Leaching losses of P have historically been considered relatively minor; however, the limited research results available indicate that annual P leaching losses from mineral soils (0.2–0.7 kg ha−1) are similar in magnitude to runoff‐P losses from turfgrass systems. One major gap in the knowledge is how P sources other than fertilizer (i.e., soil and plant tissue) and irrigation affect runoff and leaching losses of P.
Response of Heterozygous and Homozygous Imidazolinone‐Resistant Spring Wheat Genotypes to Imazamox
Authors: Willenborg Christian J. , Brûlé‐Babel Anita L. , Friesen Lyle F. , Van Acker Rene C.
Published: November 2008

Imidazolinone‐resistant (IR) spring wheat (Triticum aestivum L.) was released commercially in Canada in 2004, providing growers with a new opportunity to selectively control a broad range of weeds in wheat, including volunteer cereals and annual grasses. Imidazolinone (IMI) herbicides inhibit acetolactate synthase in susceptible (S) plants, but IR wheat plants have an altered target site that confers resistance to IMI herbicides. The IR trait has served as a phenotypic marker in a number of gene flow studies, but the response of IR F1 wheat hybrids to various doses of imazamox has not been adequately characterized. Therefore, a greenhouse study was initiated to assess the whole‐plant response of several spring wheat genotypes with different parental backgrounds to increasing doses of imazamox. No differences in biomass accumulation prior to imazamox application were detected among genotypes. Biomass accumulation after foliar treatment with imazamox was similar within all groups of genotypes, with no significant differences detected within F1 or S genotype groups. The resistance factor (GR50 ratio) of the single IR genotype tested in the study was six‐fold greater than the mean of the F1 genotypes, which was itself six‐fold greater than that of the S genotypes examined. Differential mortality was observed between some S genotypes at 3.9 g a.i. ha−1, but no differences between genotypes were observed at any other dose. The results of this study indicate that for the spring wheat genotypes assessed, parental background and market class do not affect spring wheat tolerance to imazamox. Furthermore, results indicate that the IR trait in spring wheat should provide a satisfactory marker for pollen‐mediated gene flow studies.
Molecular Mapping and Confirmation of QTLs Associated with Oleic Acid Content in N00‐3350 Soybean
Authors: Monteros Maria J. , Burton Joseph W. , Boerma H. Roger
Published: November 2008

The fatty acid composition of soybean [Glycine max (L.) Merr.] seed affects the flavor, nutritional value, and stability of the oil. Increasing oleic acid content in soybean oil would reduce the need for hydrogenation, a process that creates unhealthy trans fatty acids. The objective of this study was to map and confirm the areas of the soybean genome associated with oleic acid content from the soybean line N00‐3350 (∼583 g kg−1 oleic acid) using simple sequence repeat (SSR) markers. An F2:3 population of 259 lines from the cross of G99‐G725 × N00‐3350 was used as a mapping population, and an F2:3 population of 231 lines from the cross of G99‐G3438 × N00‐3350 was used for confirmation. Using single‐factor analysis of variance, interval mapping, and composite interval mapping, six quantitative trait loci (QTLs) for oleic acid content were found on linkage groups LG‐A1 (Satt211, R2 = 4%), LG‐D2 (Satt389, R2 = 6%), LG‐G (Satt394, R2 = 13%), LG‐G (Satt191, R2 = 7%), LG‐L (Satt418, R2 = 9%), and LG‐L (Satt561, R2 = 25%) in the G99‐G725 × N00–3350 population. All six QTLs for oleic acid were confirmed in the G99‐3438 × N00‐3350 population. The designations cqOle‐001, cqOle‐002, cqOle‐003, cqOle‐004, cqOle‐005, and cqOle‐006 have been assigned to these confirmed QTLs by the Soybean Genetics Committee. The identification of SSR markers linked to the oleic acid QTLs will facilitate the use of marker‐assisted selection (MAS) in soybean breeding programs to increase the oleic acid content in soybean seed.
Ancient Procedures for the High-Tech World: Health Benefits and Antimicrobial Compounds from the Mediterranean Empires
Authors: de Carvalho Carla C.C.R. , Caramujo Maria José
Published: November 2008

This paper reviews the benefits of the Mediterranean diet and methods developed for food processing and preservation
during the time of the ancient empires. In Antiquity, trees and herbs were harvested for culinary and medicinal
purposes, and from the everyday handling of products and keen observation, a great body of wisdom was derived by philosophers
and physicians. With modern day techniques, the suspected properties of compounds have been investigated
and the beneficial properties tested. From these studies it is apparent that olive oil, herbs, essential oils and metals, when
used with the backing of scientific knowledge can improve human health and the standards of living while respecting the
environment. Nowadays, proliferation of disinfectants and antimicrobial agents in domestic, industrial and medical environments
has contributed to the appearance of resistant microbial strains and of new pathogens. Since regulators have restricted
the use and concentrations of many preservatives, sanitizers, and antimicrobial agents, the food industry is facing
a problem to extend the shelf-life of products, and to keep the manufacturing environment clean. The application of natural
compounds and simple techniques developed by ancient Mediterranean civilizations may prove as useful as more
modern synthetic substances, thus avoiding potential threats to human health and the environment.
Real-Time Monitoring of Fibrinogen Cross-Linking on Model Biomaterial Surfaces with Quartz Crystal Microbalance
Authors: Heinze Brian C. , Yoon Jeong-Yeol
Published: November 2008

A quartz crystal microbalance was used for real-time monitoring of fibrinogen cross-linking on three model
biomaterial surfaces. Fibrinogen adsorbs slowly and forms a less rigid multi-layer on hydrophobic surfaces, while it adsorbs
quickly, forming a single mono-layer on hydrophilic surfaces. The extent of fibrinogen cross-linking is greater on
hydrophobic surfaces. Fibrinogen cross-linking can also rigidify the relatively soft coatings of poly(methyl methacrylate)
and dodecanethiol self-assembled monolayer.
Liver Enzyme Alterations in HCV-Monoinfected and HCV/HIV-Coinfected Patients
Authors: Langohr Klaus , Sanvisens Arantza , Fuster Daniel , Tor Jordi , Serra Isabel , Rey-Joly Celestino , Rivas Inmaculada , Muga Roberto
Published: November 2008

Hepatitis C virus (HCV) is the most common blood-borne infection in developed countries and co-infection with the Human Immunodeficiency Virus (HIV) is frequent in individuals with history of injecting drug use (IDU).

We aimed to analyze liver transaminases in HCV monoinfected and HCV/HIV co-infected patients to assess the effect of HIV infection on liver enzyme elevations.

We studied 429 current IDUs admitted to substance abuse treatment (82.5% males). Serum samples for liver tests, HIV infection and viral hepatitis serologies were obtained at admission. Results: Median age was 30 years (IQR:27-34), median duration of IDU was 10 years (IQR:5-14), 52% of patients were HCV/HIV co-infected, 40.8% were HCV monoinfected, and 7.2% were HCV and HIV- seronegatives. Elevated AST was associated with male gender and lower CD8+cell count in the HCV monoinfected patients, and with age and lower cholesterol in the HCV/HIV coinfected subjects. ALT elevation was associated with younger age, higher body mass index and male gender in the monoinfected patients, and with higher CD4+cell counts and lower cholesterol in the co-infected group. Male sex was strongly associated with elevated ALT and AST transaminase in the monoinfected but not in dual-infected subjects.

These data suggest that the effect of gender on liver enzymes may be lost in patients with HIV infection. The overall differences observed between groups regarding liver enzyme elevations are of clinical relevance in the management of IDUs with chronic hepatitis C.
Impaired Hyperglycemia-Induced Delay in Gastric Emptying in Patients With Type 1 Diabetes Deficient for Islet Amyloid Polypeptide
Authors: Woerle Hans J. , Albrecht Max , Linke Rainer , Zschau Silvia , Neumann Christoph , Nicolaus Mathias , Gerich John E. , Göke Burkhard , Schirra Joerg
Published: November 2008

OBJECTIVE—Slowing of gastric emptying by hyperglycemia, a physiological response to minimize postprandial hyperglycemia, may be impaired in patients with type 1 diabetes. The causes and consequences on glucose homeostasis are unknown.

RESEARCH DESIGN AND METHODS—Consequences of euglycemia- and hyperglycemia-induced changes in gastric emptying on postprandial glucose fluxes and excursions were studied in 10 healthy subjects and 15 type 1 diabetic subjects after ingestion of a mixed meal using the double isotope approach ([6,6-2H2] and [1-13C]glucose) and scintigraphic measurements of gastric emptying.

RESULTS—Gastric emptying was greater in type 1 diabetic subjects (90–120 min, P < 0.03), and 50% retention times were comparable in healthy subjects and type 1 diabetic subjects (167 ± 8 vs. 152 ± 10, P = 0.32). Hyperglycemia markedly delayed gastric emptying in healthy subjects but did not alter it in type 1 diabetic subjects (50% retention time 222 ± 18 vs. 167 ± 8 min, P = 0.003 and 148 ± 9 vs. 152 ± 10 min, P = 0.51). Plasma islet amyloid polypeptide (IAPP) increased approximately fourfold in healthy subjects (P < 0.001), whereas it was undetectable in type 1 diabetic subjects. IAPP replacement, using the analog pramlintide, in type 1 diabetic subjects slowed gastric emptying to a comparable extent, as did hyperglycemia in healthy subjects (P < 0.14), and greatly reduced postprandial hyperglycemia (P < 00.1). Meal-derived glucose appearance in plasma (10.7 ± 0.5 vs. 6.8 ± 0.7 μmol · kg−1 · min−1, P < 0.001) was reduced, and splanchnic glucose sequestration increased (14.0 ± 3.0 vs. 25.0 ± 6.0%, P = 0.04).

CONCLUSIONS—In patients with type 1 diabetes the ability to delay gastric emptying in response to hyperglycemia is impaired. This impairment contributes to exaggerated rates of meal-derived glucose appearance and, ultimately, postprandial glucose excursions.
Depression and Type 2 Diabetes Over the Lifespan
Authors: Mezuk Briana , Eaton William W. , Albrecht Sandra , Golden Sherita Hill
Published: November 2008

OBJECTIVE—It has been argued that the relationship between depression and diabetes is bi-directional, but this hypothesis has not been explicitly tested. This systematic review examines the bi-directional prospective relationships between depression and type 2 diabetes.

RESEARCH DESIGN AND METHODS—A search was conducted using Medline for publications from 1950 through 2007. Reviewers assessed the eligibility of each report by exposure/outcome measurement and study design. Only comparative prospective studies of depression and type 2 diabetes that excluded prevalent cases of depression (for diabetes predicting depression) or diabetes (for depression predicting diabetes) were included. Two sets of pooled risk estimates were calculated using random effects: depression predicting type 2 diabetes and type 2 diabetes predicting depression.

RESULTS—Of 42 full-text publications reviewed, 13 met eligibility for depression predicting onset of diabetes, representing 6,916 incident cases. Seven met criteria for diabetes predicting onset of depression, representing 6,414 incident cases. The pooled relative risk (RR) for incident depression associated with baseline diabetes was 1.15 (95% CI 1.02–1.30). The RR for incident diabetes associated with baseline depression was 1.60 (1.37–1.88).

CONCLUSIONS—Depression is associated with a 60% increased risk of type 2 diabetes. Type 2 diabetes is associated with only modest increased risk of depression. Future research should focus on identifying mechanisms linking these conditions.
Nationally Representative Medical Costs of Diabetes by Time Since Diagnosis
Authors: Trogdon Justin G. , Hylands Thomas
Published: November 2008

OBJECTIVE—This study provides nationally representative estimates for the U.S. of medical expenditures associated with diabetes by years since initial diagnosis.

RESEARCH DESIGN AND METHODS—Expenditures are estimated using cross-sectional regression analysis on the 2000–2004 Medical Expenditure Panel Survey linked to the 1998–2003 National Health Interview Survey (n = 46,203). The primary variables of interest are an indicator for self-reported diabetes and the years since diabetes diagnosis.

RESULTS—Under the base specification, a 50-year-old person just diagnosed with diabetes has medical expenditures that are 4,174 USD higher than an identical person without diabetes. On average, each additional year with diabetes increases annual medical expenditures by $158 (standard error = $38) above and beyond increases in medical expenditures due to aging. Conditional on diabetes complications, each additional year with diabetes increases annual medical expenditures by $75 (standard error = $55). Diabetes increases medical expenditures at any age, and the cumulative effect grows over time.

CONCLUSIONS—The results show the expected trajectory of medical expenditures after diagnosis of diabetes, highlighting the benefits of prevention and control as well as informing cost-effectiveness models of diabetes interventions.
Pod Yield and Mineral Concentration of Four Peanut Cultivars Following Gypsum Application With Subsurface Drip Irrigation
Authors: Sorensen Ronald B. , Butts Christopher L.
Published: November 2008

A 2-year study (2004 and 2005) was conducted where gypsum was applied to four peanut (Arachis hypogaea L.) cultivars and irrigated with subsurface drip to determine pod yield and mineral concentration of peanut plants and kernels. Gypsum rates were none, 560 and 1120 kg/ha. Peanut cultivars were C99R, Georgia Green (GG), NCV-11 (NCV), and GA-O2C (O2C). Irrigation was applied daily with subsurface drip irrigation except when precipitation exceeded the estimated daily water requirement. Average soil Ca and S concentrations increased as gypsum was applied, 5% and 20%, respectively, compared with the non-treated control. The average soil calcium to potassium (Ca∶K) ratio increased to 9.8∶1 compared with 7.6∶1 prior to applying calcium. When averaged across calcium rates, peanut leaves had 3 and 14 times higher calcium and 1.4 times higher S concentrations compared with pegs and pods, respectively. The cultivars GG and NCV had the same pod yield. Cultivars C99R and O2C had the same yield as NCV but were less than GG. Germination rates were higher when gypsum was added compared to the non-treated control and with cultivars C99R and O2C. There was no difference in vigor by gypsum application rate. Kernel Ca concentration was higher with the addition of gypsum compared to the non-treated control. Cold test germination seed vigor increased with C99R and O2C compared with GG and NCV.
Variation Among Virginia Market-Type Peanut Genotypes in Susceptibility to Tomato Spotted Wilt Virus Vectored by Thrips (Thysanoptera: Thripidae)
Authors: Riniker S. D. , Brandenburg R. L. , Kennedy G. G. , Isleib T. G. , Jordan D. L.
Published: November 2008

Tomato spotted wilt virus (TSWV), a thrips-vectored tospovirus, is an important pathogen of peanut (Arachis hypogaea L.). Development of tolerant cultivars has proven to be one of the most promising methods to manage the disease. Twenty-four genotypes of virginia market-type peanut were monitored in field tests for thrips damage, and TSWV incidence and severity during 2004 and 2005 in North Carolina. The cultivar Gregory had a higher density of adult thrips in foliage than any other genotype, while breeding lines N01057 and N03054E had the lowest density. No significant correlation was detected between thrips density or injury and TSWV incidence. Line N03036EJ had the greatest TSWV incidence, but did not differ from cultivars Gregory or Perry in incidence. Line N00033 had the least TSWV incidence and differed from the cultivars Gregory and Perry. The occurrence of late-season chlorosis or peanut yellowing death (PYD) was highly correlated with TSWV infection (P < 0.0001). Breeding line N02051ol had the greatest incidence of PYD, but did not differ statistically from Gregory or Perry. Lines N03023EF and N01083 had the least PYD incidence. Plants infected with TSWV not expressing foliar symptoms were found in far greater abundance than plants that were infected and symptomatic. Line N03036EJ had the greatest proportion of infected but asymptomatic plants; line N03054E had the least. Susceptible lines are more likely to become infected, rather than just more likely to show spotted wilt symptoms.
Designing Sampling Plans to Detect Foreign Material in Bulk Lots of Shelled Peanut1
Authors: Whitaker T. B. , Slate A. B. , Giesbrecht F. G.
Published: November 2008

When food manufacturers specify a maximum limit for the amount of foreign material (FM) in the lot, handlers estimate the true percent FM in a commercial lot by measuring FM in a small sample taken from the lot before shipment to a food manufacturer. Because of the uncertainty (variability) in FM among samples taken from the same lot, it is difficult to obtain a precise estimate of the true FM in the lot. The objectives of this study were to (1) measure the variability and FM distribution among sample test results when estimating the true lot proportion of FM in a lot of shelled peanuts, (2) compare the measured variability and FM distribution among sample test results to that predicted by the binomial distribution, (3) develop a computer model, based upon the binomial distribution, to evaluate the performance (buyer's risk and seller's risk) of sampling plan designs used to estimate FM in a bulk lot of shelled peanuts, and (4) demonstrate with the model the effect of increasing sample size to reduce misclassification of lots.

Eighty-eight samples, 9 kg (20 lb) each, were selected at random from each of six commercial lots of shelled medium runner peanuts. The percent FM (PFM), based upon number of kernels was determined for each sample. The mean, variance, and distribution among the 88 sample test results were calculated for each of the six lots. Results indicated that the variance and distribution among the 88 sample test results are very similar to that predicted by the binomial distribution. The performance of various sampling plan designs was demonstrated using the binomial distribution.
Evaluation of Resistance to Cylindrocladium Parasiticum of Runner-Type Peanut in The Greenhouse and Field
Authors: Dong W. B. , Brenneman T. B. , Holbrook C. C. , Culbreath A. K.
Published: November 2008

Identification and utilization of peanut cultivars with resistance to Cylindrocladium black rot (CBR) is a desirable approach to manage this disease. The objectives of this study were to improve greenhouse and field screening techniques for resistance to CBR, and to evaluate the reaction of selected runner-type peanut genotypes. Georgia-02C (moderately resistant to CBR) and C-99R (CBR-susceptible) were used in comparing the effectiveness of different inoculation methods in the greenhouse. Disease development was affected by both size and density of microsclerotia in soil. Use of microsclerotia at a size of ≥150 to <250 µm and a density of 1 to 5 microsclerotia/g soil provided the best separation the CBR-resistant cultivar Georgia-02C and the susceptible C-99R based on root rot severity. Genotypes with varying resistance to CBR were evaluated by growth in a naturally infested field, and by inoculating plants in the field and greenhouse. Disease incidence and severity at harvest were the most effective parameters for evaluating CBR resistance in the field and greenhouse, respectively. The cultivars Georgia-02C and Georganic had the lowest disease incidence, whereas C-99R and DP-1 had the highest disease incidence in a naturally infested field in 2005 and 2006. Incidence of CBR was moderate for Georgia-01R in both years, but was inconsistent for C34-24-85. Georgia-02C and Georganic also showed partial resistance to CBR in greenhouse tests. Inoculated plants in the field had similar reaction with Georgia-02C and Georganic showing higher CBR resistance than C-99R and DP-1 in both 2006 and 2007. The root rot severities for genotypes Georgia-02C and Georganic were lower than those for C-99R and DP-1. Incidence of CBR in the naturally infested field was significantly correlated with CBR incidence in the inoculated plants in the field (r  =  0.84, P ≤ 0.01), but neither was correlated with disease ratings for greenhouse experiments. Peanut genotypes are most reliably screened by inoculating plants in the field or using uniformly infested fields. Further study is needed to improve greenhouse screening procedures.
A New Cytotoxic Friedelane Acid – Pluricostatic Acid – and Other Compounds from the Leaves of Marila pluricostata
Authors: Olmedo Dionisio  A. , López-Pérez José  L. , Del Olmo Esther , Vásquez Yelkaira , San Feliciano Arturo , Gupta Mahabir  P.
Published: November 2008

Bioassay-guided fractionation of the dichloromethane extract of the leaves of Marila pluricostata led to the isolation of 2α,3β-dihydroxy-D:A-friedoolean-28-oic acid (pluricostatic acid), a new friedelane triterpenoid, (1), ten known triterpenoids and three sterols. Their chemical structures were elucidated through spectroscopic analysis. The less polar fractions, on GC/MS analysis and comparison with a MS library, resulted in the identification of twenty four sesquiterpenoids. The new triterpenoid acid 1 showed cytotoxicity against the MCF-7, H-460, and SF-268 human cancer cell lines with GI50 values from 1.2 to 3.3 μg/mL.
An Open Localization and Local Communication Embodied Sensor
Authors: Gutiérrez Alvaro , Campo Alexandre , Dorigo Marco , Amor Daniel , Magdalena Luis , Monasterio-Huelin Félix
Published: November 2008

In this paper we describe a localization and local communication system which allows situated agents to communicate locally, obtaining at the same time both the range and the bearing of the emitter without the need of any centralized control or any external reference. The system relies on infrared communications with frequency modulation and is composed of two interconnected modules for data and power measurement. Thanks to the open hardware license under which it is released, the research community can easily replicate the system at a low cost and/or adapt it for applications in sensor networks and in robotics.
The Impact of Interfacial Mixing on Förster Transfer at Conjugated Polymer Heterojunctions
Authors: Higgins Anthony M. , Cadby Ashley , Lidzey David G. , Dalgliesh Robert M. , Geoghegan Mark , Jones Richard A. L. , Martin Simon J. , Heriot Sasha Y.
Published: November 2008

Neutron reflectivity and photoluminescence measurements are reported on bilayers of polyfluorene‐based conjugated polymers. By using a novel thermal processing procedure it is possible to control the width of the interface between poly(9,9‐dioctylfluorene) (F8) and poly(9,9‐dioctylfluorene‐alt‐benzothiadiazole) (F8BT), and measure the impact of interfacial roughness on the resonant energy transfer of excitons at the interface (Förster transfer). It is found that increasing the root mean square (rms) roughness of the F8/F8BT interface over the range of ∼1 nm to ∼5 nm leads to a greatly enhanced Förster transfer from F8 to F8BT molecules. By comparing photoluminescence measurements with simple calculations it is concluded that the level of enhancement of the F8BT peak at rough interfaces can only be adequately explained if mixing of F8 and F8BT at a molecular level dominates over the interfacial roughness due to thermally excited capillary waves.
Distinct Nanostructures from a Molecular Shuttle: Effects of Shuttling Movement on Nanostructural Morphologies
Authors: Zhou Weidong , Xu Jialiang , Zheng Haiyan , Yin Xiaodong , Zuo Zicheng , Liu Huibiao , Li Yuliang
Published: November 2008

A solvent driven molecular shuttle that contains a TCBD chromophore and in which the macrocycle can be positioned close to or far from the TCBD unit with a change of solvent is prepared. Several distinct nanostructures are obtained by control of the shuttling movement of the macrocycle: i) in a mixed solvent of CHCl3/n‐C6H14 (1/1, v/v), the macrocycle locates at the peptide station, and interlaced nanofibers form as a result of the extended intermolecular dipole–dipole interactions of the TCBD units; ii) in a solvent of dimethyl sulfoxide, the macrocycle moves along the long alkyl‐chain, and worm‐like nanoparticles form because the macrocycle obstructs the intermolecular dipole–dipole interactions of the TCBD units. This system confirms that the molecular aggregation behaviors can be controlled by the shuttling movement of the macrocycle. Exploitation of the molecular shuttle to control the molecular aggregation behaviors will provide greater understanding in the field of molecular shuttle applications.
Heat capacity measurement by flow calorimetry: An exact analysis
Authors: Hei T. K. , Raal J. D.
Published: November 2008

The principal unsolved problem in flow calorimetry for liquid heat capacity measurement accurate accounting for heat loss from the heater lead‐in wires as a function of system properties is analyzed by exact procedures for a five‐zone calorimeter model. Temperature distributions in the fluid, and bi‐metal wire are obtained from solutions of the governing third‐order ODE in the fluid temperature for realistic boundary conditions. Conductive heat losses at the fluid exit qHL/q̇ are large (up to 20% of energy input), and physical property and flow rate dependent. A new correlating equation for (qHL/q̇) gives separately and explicitly, for the first time, its dependence on calorimeter characteristics, flow rates and fluid properties. Experiments on five pure liquids confirmed the predictions of the theoretical model and produced Cp values in close agreement with literature data. Fluid friction and small convection heat losses (UiAi (ΔT)lm) were accounted for experimentally. © 2008 American Institute of Chemical Engineers AIChE J, 2009
Novel biodegradable flocculating agents prepared by grafting polyacrylamide to Konjac
Authors: Xie Chenxin , Feng Yujun , Cao Weiping , Teng Houkai , Li Jufeng , Lu Zhiyong
Published: November 2008

Grafting copolymers of polyacrylamide (PAM) with Konjac gum (KGM) have been synthesized using ceric‐ion‐induced initiation technique. The copolymers were characterized using several instrumental techniques, including infrared (IR) spectroscopy, elementary analysis, scanning electron microscopy (SEM), size exclusion chromatography (SEC) analysis, and intrinsic viscosity to confirm the success of grafting. The flocculation performance of graft copolymers was characterized by two methods. One was to study the relationship between the flocculants doses in kaolin suspension and the supernatant transmittance, and the other is to examine the time dependence of sediment height of kaolin suspensions. It was found that the graft copolymer is better than KGM and pure PAM. Biodegradation behavior was testified by monitoring the decay of relative viscosities, and approved by KGM ether bonds breaking in IR spectra and the molecule weight reduction in SEC analysis. The results indicate that the grafted KGM copolymers have improved both, flocculation performance and better biodegradable properties than the unmodified parent KGM and pure PAM. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Study of the biodegradation behavior of soy protein‐grafted polyethylene by the soil burial method
Authors: Kaur Inderjeet , Bhalla T. C. , Deepika N. , Gautam Neena
Published: November 2008

In this article, we report on the biodegradation of soy‐protein‐grafted polyethylene, which was successfully synthesized by a graft copolymerization method with benzoyl peroxide as the radical initiator. The biodegradation behavior of the grafted polyethylene was ascertained by a soil burial test. The weight‐loss percentage was measured as a function of the number of days, and it was observed that the percentage weight loss increased with increasing number of days. To further substantiate the degradation, microanalysis of the soil containing the samples was carried out. An increase in microorganism colonies was observed with increasing number of days. The hydrolysis of the samples taken from the soil after a specified number of days also corroborated the findings and revealed a continuous loss of weight. The effect of the degradation of the grafted samples on the growth of plants (wheat and soybean) was studied, and we observed that the products of degradation were not harmful to the growth of the plants. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Application of ultraviolet photografting technology to acrylamide/polyethylene to improve the interfacial adhesion of polyethylene/unsaturated polyester resin composites
Authors: Chiu Hsien‐Tang , Shong Zhi‐Jian
Published: November 2008

This study was divided into two sections. In the first part, we used ultraviolet (UV) rays in the wavelength range 300–400 nm to remove the hydrogen atom from polyethylene (PE) and worked with a hydrophilic monomer to complete the grafting action. In the second part, we used the best conditions derived from the previous film grafting and applied them to fibers to achieve excellent adhesion for application in composite materials. For the handling process of the PE film, we initially used acrylamide (AM) as the monomer and then added acetone and benzophenone (BP) to form a reactive solution for the advanced photografting process. In general, the optimum concentrations of the monomer solutions obtained from the photografting of PE films were 2 mol/L of AM and 0.2 mol/L of BP. The UV irradiation time was fixed at 30 min. The optimum grafting conditions achieved in the first part of this research were applied in the photografting process for the PE fiber bundles in the second part. The unsaturated polyester (UP) resins were spread over the outer surfaces of the modified fibers. This was done to strengthen and increase the interface between the UP resins and the modified PE fiber. During the curing experiment of the grafted fiber bundles in the resin coatings, the best material quality was obtained under the following conditions: hardener content = 0.85% (relative to the UP resin weight), oven temperature = 80°C, and time frame = 5 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Immobilization cyclen copper (II) on merrifield resin: Efficient oxidative cleavage of plasmid DNA
Authors: Li Kun , Zhang Ji , Zhang Zhong‐Wei , Xiang Yong‐Zhe , Lin Hong‐Hui , Yu Xiao‐Qi
Published: November 2008

Merrifield resin‐supported cyclen (MRC) was directly prepared by attaching 1, 4, 7, 10‐tetraazacyclododecane (cyclen) to Merrifield resin (MR). Subsequent coordination with Cu(II), Co(II), and Ni(II) gave immobilized cyclen complex MRC‐Cu, MRC‐Co, and MRC‐Ni as “solid artificial enzymes.” These complexes were characterized by elemental analysis, IR spectroscopy, ICP‐AES, and scanning electron microscopy (SEM). Furthermore, the DNA cleavage activities of these complexes were investigated by agarose gel electrophoresis. The results indicated that MRC‐Cu was superior to other solid artificial enzymes, and the cleavage process was carried out via oxidative pathway. Moreover, the solid catalyst MRC‐Cu was very stable and it could be reused at least four times without any loss of catalytic activity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Copolymerization of ethylene and propylene catalyzed by novel magnesium chloride supported, vanadium‐based catalysts
Authors: Jiang Tao , Du Wei , Zhang Li , Song Xianfeng , Zhang Guangyuan , Ning Yingnan
Published: November 2008

Two novel magnesium chloride supported, vanadium‐based Ziegler–Natta catalysts with 9,9‐bis(methoxymethyl)fluorene and di‐i‐butyl phthalate as internal donors were prepared and used in the copolymerization of ethylene and propylene. The catalytic behaviors of these catalysts were investigated and compared with those of traditional magnesium chloride supported, vanadium‐based catalysts without internal donors. Differential scanning calorimetry, gel permeation chromatography, and 13C‐NMR spectroscopy analysis were performed to characterize the melting temperatures, molecular weights, and molecular weight distributions as well as structures and compositions of the products. The copolymerization kinetic results indicated that the novel catalyst with 9,9‐bis(methoxymethyl)fluorene as an internal donor had the highest catalytic activity and optimal kinetic behavior in ethylene–propylene copolymerization with an ethylene/propylene molar ratio of 44/56. Low‐crystallinity and high‐molecular‐weight copolymers were obtained with these novel magnesium chloride supported, vanadium‐based catalysts. The reactivity ratio data indicated that the catalytic systems had a tendency to produce random ethylene–propylene copolymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of poly(vinyl pyrrolidone) concentration and coagulation bath temperature on the morphology, permeability, and thermal stability of asymmetric cellulose acetate membranes
Authors: Saljoughi Ehsan , Amirilargani Mohammad , Mohammadi Toraj
Published: November 2008

Cellulose acetate (CA) is widely used in membrane processes. In this study, CA (weight‐average molecular weight = 52,000) was mixed with poly(vinyl pyrrolidone) (PVP; weight‐average molecular weight = 15,000) as an additive in 1‐methyl‐2‐pyrrolidone as a solvent. The phase‐inversion method was used for the preparation of flat‐sheet membranes. The effects of PVP concentration and coagulation bath temperature (CBT) on the morphology, pure water permeation flux, and thermal stability of the prepared membranes were studied and are discussed in this article. The solute rejection of the developed CA membranes was quantified with an insulin protein solution. The results showed that an increase in the CBT levels from 0 to 23°C along with an increase in the PVP concentration in the cast film from 0 to 1.5 wt % resulted in an increase in the macrovoid formation in the membrane sublayer, an increase in the pure water flux (PWF), and a decrease in insulin rejection. Further increases in the PVP concentration from 1.5 to 3, 6, and 9 wt % resulted in gradual suppression of the macrovoid formation, a decrease in PWF, and an increase in insulin rejection. Higher PVP concentrations and lower CBT levels also appeared to result in higher glass‐transition temperatures. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Exploring the relationships between work task and search task in information search
Authors: Li Yuelin
Published: November 2008

To provide a basis for making predictions of the characteristics of search task (ST), based on work task (WT), and to explore the nature of WT and ST, this study examines the relationships between WT and ST (inter‐relationships) and the relationships between the different facets of both WT and ST (intra‐relationships), respectively. A faceted classification of task was used to conceptualize work task and search task. Twenty‐four pairs of work tasks and their associated search tasks were collected, by semistructured interviews, and classified based on the classification. The results indicate that work task shapes different facets or sub‐facets of its associated search tasks to different degrees. Several sub‐facets of search task, such as Time (Length), Objective task complexity, and Subjective task complexity, are most strongly affected by work task. The results demonstrate that it is necessary to consider difficulty and complexity as different constructs when investigating their influence on information search behavior. The exploration of intra‐relationships illustrates the difference of work task and search task in their nature. The findings provide empirical evidence to support the view that work task and search task are multi‐faceted variables and their different effects on users' information search behavior should be examined.
How much and where? Private versus public universities' publication patterns in the information systems discipline
Authors: Holsapple Clyde W. , O'Leary Daniel
Published: November 2008

In most disciplines of scholarly endeavor, there are many efforts at ranking research journals. There are two common methods for such efforts. One of these is based on tabulations of opinions offered by persons having some kind of relationship with the discipline. The other is based on analyses of the extent to which a journal's articles have been cited by papers appearing in some selected set of publications. In either case, construction of a journal ranking for a discipline makes no effort to distinguish between private and public universities. That is, data are aggregated from both private and public faculty researchers. It is thus assumed that the resultant ranking is applicable for both kinds of institutions. But, is this assumption reasonable? The answer is very important because these rankings are applied in the evaluation of promotion, tenure, and merit cases of faculty members working in a discipline. Here, we examine this widespread bibliometric assumption through the use of a ranking methodology that is based on the actual publishing behaviors of tenured researchers in a discipline. The method is used to study the behaviors of researchers at leading private universities versus those at leading public universities. Illustrating this approach within the information systems discipline, we find that there are indeed different publication patterns for the private versus public institutions. This finding suggests that journal‐ranking exercises should not ignore private–public distinctions and that care should be taken to avoid evaluation standards that confound private and public rankings of journals.
Total Synthesis of (−)‐Apratoxin A, 34‐Epimer, and Its Oxazoline Analogue
Authors: Numajiri Yoshitaka , Takahashi Takashi , Doi Takayuki
Published: November 2008

A concise and convergent total synthesis of the highly cytotoxic marine natural product apratoxin A is accomplished by an 18‐step linear sequence. The high sensitivity of the thiazoline, bearing an adjacent β‐hydroxyl group at the C35‐position, results in the assembly process requiring the inclusion of appropriate protecting groups and the careful optimization of all individual transformations. In the synthesis of 3,7‐dihydroxy‐2,5,8,8‐tetramethylnonanoic acid (Dtena), the three reagent‐controlled asymmetric reactions enables us to introduce four chiral carbon centers in a dihydroxylated fatty acid moiety. Formation of the hindered ester and sterically‐unfavorable N‐methylamide bonds were successfully demonstrated. The thiazoline in apratoxin A was constructed by Tf2O and Ph3PO‐mediated dehydrative cyclization, and final macrocyclization was achieved between N‐methylisoleucine and proline residues. Moreover, an oxazoline analogue and a C34 epimer of apratoxin A have also been elaborated in a similar approach. This synthetic route would enable assembly of other analogues differing in stereocenters of Dtena and their amino acids.
Dynamical mixing of two stellar populations in globular clusters
Authors: Decressin T. , Baumgardt H. , Kroupa P.
Published: November 2008

Stars in globular clusters (GCs) exhibit a peculiar chemical pattern with strong abundance variations in light elements along with a constant abundance in heavy elements. These abundance anomalies can be explained by a primordial pollution due to a first generation of fast rotating massive stars which released slow winds into the ISM from which a second generation of chemically anomalous stars can be formed. In particular the observed ratio of anomalous and standard stars in clusters can be used to constrain the dynamical evolution of GCs as around 95% of the standard stars need to be lost by the clusters. We show that both residual gas expulsion during the cluster formation and long term evolution are needed to achieve this ratio. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamics of the disks of nearby galaxies
Authors: Fuchs B.
Published: November 2008

I describe how the dynamics of galactic disks can be inferred by imaging and spectroscopy. Next I demonstrate that the decomposition of the rotation curves of spiral galaxies into the contributions by the various components of the galaxies is highly degenerate. Constraints on the decomposition can be found by considering implications for the dynamics of the galactic disks. An important diagnostic is the Toomre Q stability parameter which controls the stability of a galactic disk against local Jeans collapse. I also show how the density wave theory of galactic spiral arms can be employed to constrain the mass of a galactic disk. Applying both diagnostics to the example of NGC2985 and discussing also the implied massto‐light ratio I demonstrate that the inner parts of the galaxy, where the optical disk resides, are dominated by baryons. When I apply this method to the disks of low surface brightness galaxies, I find unexpectedly high mass‐to light ratios. These could be explained by population synthesis models which assume a bottom heavy initial mass function similar to the recently proposed ‘integrated galactic initial mass function’. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Massive Black Hole recoil in high resolution hosts
Authors: Guedes J. , Diemand J. , Zemp M. , Kuhlen M. , Madau P. , Mayer L. , Stadel J.
Published: November 2008

The final inspiral and coalescence of a black hole binary can produce highly beamed gravitational wave radiation. To conserve linear momentum, the black hole remnant can recoil with “kick” velocity vkick ≤ 4000 km/s. We present two sets of full N‐body simulations of recoiling massive black holes (MBH) in high‐resolution, non‐axisymmetric potentials. The host to the first set of simulations is the main halo of the Via Lactea I simulation (Diemand et al. 2007). The nature of the resulting orbits is investigated through a numerical model where orbits are integrated assuming an evolving, triaxial NFWpotential, and dynamical friction is calculated directly from the velocity dispersion along the major axes of the main halo of Via Lactea I. By comparing the triaxial case to a spherical model, we find that the wandering time spent by the MBH is significantly increased due to the asphericity of the halo. For kicks larger than 200 km/s, the remnant MBH does not return to the inner 200 pc within 1 Gyr, a timescale an order of magnitude larger than the upper limit of the estimated QSO lifetime. The second set of simulations is run using the outcome of a high‐resolution gas‐rich merger (Mayer et al. 2007) as host potential. In this case, a recoil velocity of 500 km/s cannot remove the MBH from the nuclear region. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Status and future of MUSE
Authors: Harfst S. , Zwart S. Portegies , McMillan S.
Published: November 2008

We present MUSE, a software framework for combining existing computational tools from different astrophysical domains into a single multi‐physics, multi‐scale application. MUSE facilitates the coupling of existing codes written in different languages by providing inter‐language tools and by specifying an interface between each module and the framework that represents a balance between generality and computational efficiency. This approach allows scientists to use combinations of codes to solve highly‐coupled problems without the need to write new codes for other domains or significantly alter their existing codes. MUSE currently incorporates the domains of stellar dynamics, stellar evolution and stellar hydrodynamics for studying generalized stellar systems. We have now reached a “Noah's Ark” milestone, with (at least) two available numerical solvers for each domain. MUSE can treat multi‐scale and multi‐physics systems in which the time‐ and size‐scales are well separated, like simulating the evolution of planetary systems, small stellar associations, dense stellar clusters, galaxies and galactic nuclei. In this paper we describe two examples calculated using MUSE: the merger of two galaxies and an N ‐body simulation with live stellar evolution. In addition, we demonstrate an implementation of MUSE on a distributed computer which may also include special‐purpose hardware, such as GRAPEs or GPUs, to accelerate computations. The current MUSE code base is publicly available as open source at http://muse.li. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards an accurate model for the Antennae galaxies
Authors: Karl S.J. , Naab T. , Johansson P.H. , Theis Ch. , Boily C.M.
Published: November 2008

In the framework of hierarchical structure formation ellipticals can form from merging of smaller disk galaxies. The nearby interacting ‘Antennae’ galaxy pair (NGC 4038/39) is one of the best‐studied local systems of merging spirals, thus presenting us with an ideal laboratory for the study of galaxy evolution models. The Antennae are believed to be in a state prior to their final encounter with rapid subsequent merging, which puts them in the first position of the Toomre (1977) merger sequence. Here we present first numerical high‐resolution, self‐consistent, smoothed particle hydrodynamics (SPH) simulations of the Antennae system, including star formation and stellar feedback, and compare our results to VLA H I observations by Hibbard et al. (2001). We are able to obtain a close, but not yet perfect match to the observed morphology and kinematics of the system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pairing mechanisms for binary stars
Authors: Kouwenhoven M.B.N. , Brown A.G.A. , Goodwin S.P. , Zwart S.F. Portegies , Kaper L.
Published: November 2008

Knowledge of the binary population in stellar groupings provides important information about the outcome of the star forming process in different environments. Binarity is also a key ingredient in stellar population studies and is a prerequisite to calibrate the binary evolution channels. In these proceedings we present an overview of several commonly used methods to pair individual stars into binary systems, which we refer to as the pairing function.Many pairing functions are frequently used by observers and computational astronomers, either for the mathematical convenience, or because they roughly describe the expected outcome of the star forming process. We discuss the consequences of each pairing function for the interpretation of observations and numerical simulations. The binary fraction and mass ratio distribution generally depend strongly on the selection of the range in primary spectral type in a sample. These quantities, when derived from a binary survey with a mass‐limited sample of target stars, are thus not representative for the population as a whole. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local Galactic kinematics from revised Hipparcos catalogue
Authors: Kong D.‐L. , Zhu Z. , Yuan F.‐T.
Published: November 2008

Local stellar kinematic properties are reinvestigated. A main‐sequence sample of 12718 objects is picked out from a total of 117955 Hipparcos stars and some local kinematical parameters are re‐determined by dividing 19 subsamples mainly according to color index. The results are reasonably consistent with those derived from the initial Hipparcos data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)