cssi/SciSciGPT-SciSciNet huggingface dataset:
Delaying Insect Adaptation to Transgenic Plants: Seed Mixtures and Refugia Reconsidered

Genetically engineered plants expressing insecticidal proteins from the bacterium Bacillus thuringiensis can provide safe and effective pest control, but they will also select intensely for insect adaptation to the toxins. Mallet & Porter (Proc. R. Soc. Lond. B 250, 165 (1992)) used a model to compare two planting strategies for delaying crop failure: \`seed mixtures' of toxic and toxin-free plants within fields, and \`refugia' of toxinfree fields. They concluded that `if insects can move from plant to plant, seed mixtures may actually hasten insect resistance compared with pure stands of toxic plants'. In the present study, the model of Mallet & Porter was used to evaluate pure stands of toxic plants, seed mixtures, refugia, and mixtures+refugia. Across a broad range of conditions, seed mixtures delayed development of insect resistance compared with pure stands of toxic plants. The relative merits of seed mixtures and refugia depend upon untested assumptions about pest movement, mating, and inheritance of resistance. Minimizing exposure of pests to toxins in space and time is the surest way to preserve the efficacy of transgenic plants.
Chronic hepatitis B and C: update on therapy

Chronic infections with HBV and HCV are a major cause of liver-associated morbidity and mortality worldwide. An increased knowledge of HBV and HCV virology, natural history and predictors of virological response has led to the development of new strategies to improve treatment outcomes. The use of new antiviral agents with greater potency and a high genetic barrier to resistance, as well as on-treatment monitoring of virological response, may result in improved outcomes in HBV therapy. A greater understanding of predictors of virological response has led to the ability to individualize therapy in chronic HCV infection. Several new antiviral agents specifically targeting HCV are in development and should have a major impact on treatment response rates over the next few years.
Didanosine: Long-Term Follow-Up of Patients in a Phase 1 Study

Long-term follow-up of 44 patients with AIDS or AIDS-related complex (ARC) in a phase 1 trial of didanosine is reported. These patients were monitored for as long as 72 weeks (mean, 34 weeks) for toxicity and activity of didanosine. Pancreatitis and neuropathy, the major clinical toxicities, developed infrequently at the doses of didanosine (250-750 mg/d) employed during the latter part of the study. Consistent hematologic toxicity was not encountered; moreover, mean values for hematologic parameters such as hemoglobin concentration, white blood cell count, neutrophil count, lymphocyte count, and platelet count improved for up to 20-60 weeks. CD4 counts increased significantly through 10 weeks of therapy and in some patients remained at or above counts at enrollment for as long as 60 weeks. Serum concentrations of p24 antigen decreased significantly and remained at the decreased level for up to 48 weeks. An initial diagnosis of ARC (as opposed to AIDS), an initial CD4 count of > 100/mm3, and an increase in CD4 counts during the first 10 weeks of therapy were associated with a higher rate of survival and with lower rates of development of opportunistic infections and of other clinical manifestations of disease progression.
The Role of Host Gender in the Pathogenesis of Cryptococcus neoformans Infections

Cryptococcus neoformans (Cn) is a pathogenic yeast and the cause of cryptococcal meningitis. Prevalence of disease between males and females is skewed, with males having an increased incidence of disease. Based on the reported gender susceptibility differences to Cn in the literature, we used clinical isolates from Botswanan HIV-infected patients to test the hypothesis that different gender environments exerted different selective pressures on Cn. When we examined this data set, we found that men had significantly higher risk of death despite having significantly higher CD4+ T lymphocyte counts upon admittance to the hospital. These observations suggested that Cn strains are uniquely adapted to different host gender environments and that the male immune response may be less efficient in controlling Cn infection. To discriminate between these possibilities, we tested whether there were phenotypic differences between strains isolated from males and females and whether there was an interaction between Cn and the host immune response. Virulence phenotypes showed that Cn isolates from females had longer doubling times and released more capsular glucoronoxylomannan (GXM). The presence of testosterone but not 17-β estradiol was associated with higher levels of GXM release for a laboratory strain and 28 clinical isolates. We also measured phagocytic efficiency, survival of Cn, and amount of killing of human macrophages by Cn after incubation with four isolates. While macrophages from females phagocytosed more Cn than macrophages from males, male macrophages had a higher fungal burden and showed increased killing by Cn. These data are consistent with the hypothesis that differential interaction between Cn and macrophages within different gender environments contribute to the increased prevalence of cryptococcosis in males. This could be related to differential expression of cryptococcal virulence genes and capsule metabolism, changes in Cn phagocytosis and increased death of Cn-infected macrophages.
Xenobiotic-metabolizing enzyme activity in human non-small-cell derived lung cancer cell lines

Abstract Human lung cancer cell lines in culture were investigated for the expression of monooxygenase and other xenobiotic-metabolizing enzyme activities. Two brochiolo-alveolar carcinoma derived cell lines (NCI-H322 and NCI-H358) and two small-cell carcinoma derived cell lines (NCI-H128 and NCI-H69) were used. Previous work has shown that NCI-H322 has ultrastructural features of Clara cells while NCI-H358 shows characteristics of alveolar type II cells [Schuller et al ., Proc. Am. Ass. Cancer Res . 26 , 27 (1985)]. NCI-H128 and NCI-H69 show very poor differentiation of cytoplasmic organelles. Cytochrome P-450 levels were spectroscopically detectable only in NCI-H322. Both NCI-H322 and NCI-H358, but not NCI-H69 and NCI-H128, exhibited aryl hydrocarbon hydroxylase (using benzo[ a ] pyrene as substrate) and ethoxycoumarin O -deethylase activities. These activities were highly inducible following pretreatment with the polycyclic aromatic hydrocarbons (PAH) β-naphthoflavone or benzo[ a ] anthracene. The PAH produced a 2-fold increase in spectroscopically detectable cytochrome P-450 levels in NCI-H322. Following induction, cytochrome P-450 was also spectroscopically detectable in NCI-H358. No aldrin epoxidase activity was present in either untreated or pretreated cell lines. Pretreatment with phenobarbitone or dexamethasone did not induce the aryl hydrocarbon hydroxylase activity in either NCI-H322 or NCI-H358. The ethoxycoumarin O -deethylase activity in β-naphthoflavone-pretreated NCI-H322 and NCI-H358 was inhibited in a concentration-dependent manner by ellipticine, α-naphthoflavone, cimetidine or metyrapone. Untreated NCI-H322 and NCI-H358 also contained cytochrome b 5 , NADPH cytochrome c reductase and epoxide hydrolase activities. None of these enzyme activities measured was detectable in the untreated or pretreated small-cell derived cancer cell lines (NCI-H128 and NCI-H69). These data show that the two bronchio-alveolar carcinoma derived cell lines (NCI-H322 and NCI-H358) exhibit cytochrome P-448-dependent monooxygenase activity and may thus prove useful to study the processes of xenobiotic activation in human lung.
Information behavior of small groups: implications for design of digital libraries

We report findings of a study that investigates the information behavior of online small groups engaged in math problem solving and discuss the implications for designing digital libraries that can support learning of younger students and their broader information practices.
Structure of alkaline phosphatase with zinc/magnesium cobalt or cadmium in the functional metal sites

Abstract Crystals of alkaline phosphatase (EC 3.1.3.1; Mr 94,000) grown at pH 9.5 from 2.25 m-(NH4)2SO4 with 5 × 10−5 m-Zn and 10−2 m-Mg present were analyzed by X-ray diffraction at pH 7.5 in 2.66 m-(NH4)2SO4 with 10−2 m-Zn and 10−2 m-Mg present. The crystals are orthorhombic with a = 195.5 A , b = 168.3 A and c = 76.33 A , and the space group is I222. X-ray phases were determined by the multiple isomorphous replacement and anomalous dispersion method using K2PtCl4, KAu(CN)2 and K2OsO4 derivatives. The electron density maps and analysis of metal binding sites reveal one molecule per asymmetric unit with an internal, non-crystallographic, 2-fold rotation axis relating the subunits. Each subunit contains a major α β domain with a seven-stranded β-sheet flanked by helices. The sheets are roughly coplanar but the general direction of the strands in each is at 20 ° to the rotation axis and thus 40 ° from each other. The helical content of the α β domain is approximately 27% of the 459 residues in the monomer and the β content is approximately 7%. The chains in a smaller domain are more convoluted and less easily characterized than in the α β domain. In both there is extensive monomer-monomer contact. Removal of the zinc and magnesium from the parent crystal produces a stable apoenzyme crystal and addition of cobalt at 10−2 m or cadmium at 10−2 or 5 × 10−2 m reveals seven metal binding sites per dimer. The active centers are 32 A apart and each is shown by anomalous dispersion data to contain two metal binding sites, A and B. The cadmium derivative refinement determined the A-B separation to be 4.9 A. Comparison of the parent and apo structures by means of difference maps reveals the double metal site with Zn at A and probably Mg at B. A prominent, partially resolved peak centered 7 A away is interpreted as a stabilization of the backbone in this position by the metal ion co-ordination to a side-chain. Several negative peaks within 10 A of the metals indicate local differences between apo and native structures but no significant differences are seen in the other parts of the molecule. At 5 × 10−2 m-Cd two metal sites (D and D′) are found 25.5 A from the active center, on the surface of the minor domain. They are related to each other by the molecular 2-fold axis with a D-D′ distance of 25 A. The seventh Cd site, E, is 20 A from the active center, on the major domain, near a crystalline contact region, and devoid of any molecular symmetry mate. The apparent dissociation constants for cadmium at the A, B and D sites (and A′, B′, D′) are 3 × 10−3 m, 1.5 × 10−1 m and 1.3 × 10−2 m, respectively. Thus in these conditions cadmium is seen to distribute between A and B sites when the combined stoichiometry is two metal ions per dimer.
Effects of a fluorinated bisphosphonate on bone remodeling in vivo

Abstract A new fluorinated bisphosphonate, difluoromethylene bisphosphonate (F 2 MBP), was studied for its effects on physiologic bone remodeling in the actively growing rat tibia. Young male Sprague-Dawley rats were given daily subcutaneous injections of either saline (control) or 30 mg/kg per day of F 2 MBP, dichloromethylene bisphosphonate (Cl 2 MBP), or 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) for 30 days. Microradiographs of the epiphysealmetaphyseal region of tibiae from animals treated with either F 2 MBP or Cl 2 MBP demonstrated increased radiodensity but, unlike those treated with HEBP, without an increase in the width of the epiphyseal growth plate. Quantitative analyses of these microradiographs showed that there was an increase of calcified tissue in the metaphyseal region in all diphosphonate groups when compared with controls. However, the HEBP-treated animals exhibited significantly less increase than either F 2 MBP-treated or Cl 2 MBP-treated rats. In addition, the total area of calcified tissue in the diaphyseal transverse sections was greater in the F 2 MBP-treated animals than in controls. Elemental calcium, phosphorus, and fluorine, as detected by the electron probe, also increased in the metaphyseal region of the F 2 MBP-treated animals, but no significant differences in the calcium: phosphorus ratio were found among the control, F 2 MBP, and Cl 2 MBP treatment groups, indicating no alterations in the chemical composition of bone. The greater amount of fluorine in the tibiae of F 2 MBP-treated animals reflected the presence of the F 2 MBP molecule. Thus, this study has demonstrated that this new fluorinated bisphosphonate, like Cl 2 MBP, inhibits physiologic bone remodeling without disturbing mineralization. Furthermore, the presence of fluorine in F 2 MBP allows the precise localization of the incorporation of the bisphosphonate within the bone.
Electoral systems and democratization in Southern Africa

by Andrew Reynolds, Oxford University Press, 1999, xiv+341 pp., hbk, £35, ISBN 0 19 829510 3.
London's metropolitan government the report of the royal commission

The problem which London faces is similar tothat confironting metropolitan areas in the United States. Mr. Cohen, who is now in England, describes the work of the Royal Commission on the Government of London.
A mixed-integer programming model for evaluating distribution configurations in the steel industry

Abstract In this paper, a mixed-integer programming model is developed to aid management in the analysis of a distribution problem in the steel industry. In this problem, the company has seven service centers located in the northeastern part of the country. In order to maintain reasonable inventory levels and fast customer service, there is a considerable amount of transshipment between the service centers. The model takes as inputs supply and demand levels, transportation costs, loading/unloading costs and potential routes. The output of the model is a minimum cost distribution schedule. The model allows management to quickly evaluate various distribution scenarios, including the establishment of a central transfer facility.
Survey of the NF(b->X) visible laser candidate

Three chemical systems have been proposed for generating a visible electronic transition laser on NF(b - X) at lambda = 529 nm. Each concept involves generating NF(a 1 Delta) and upconverting it to NF(b 1 Sigma). The stimulated emission cross section for NF(b - X) is small due to a small Einstein coefficient and rovibronic dilution of the oscillator strength. Large inversion densities are mandated which raise problems with gas phase side reactions involving the collision of two excited state species. In addition, the combination of low gain and high energy storage density results in large intracavity fluxes for a real laser device.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Advances in Human B Cell Phenotypic Profiling

To advance our understanding and treatment of disease, research immunologists have been called-upon to place more centralized emphasis on impactful human studies. Such endeavors will inevitably require large-scale study execution and data management regulation (“Big Biology”), necessitating standardized and reliable metrics of immune status and function. A well-known example setting this large-scale effort in-motion is identifying correlations between eventual disease outcome and T lymphocyte phenotype in large HIV-patient cohorts using multiparameter flow cytometry. However, infection, immunodeficiency, and autoimmunity are also characterized by correlative and functional contributions of B lymphocytes, which to-date have received much less attention in the human Big Biology enterprise. Here, we review progress in human B cell phenotyping, analysis, and bioinformatics tools that constitute valuable resources for the B cell research community to effectively join in this effort.
Hematoma block versus sedation for the reduction of distal radius fractures in children.

Purpose To determine which mode of anesthesia, hematoma block (HB) or procedural sedation (PS), was preferable for distal radius fracture (DRF) reduction in children. Methods Fifty-two children (mean age, 12 y; range, 5–16 y) presenting with DRFs requiring reduction were prospectively enrolled and offered either PS or HB for anesthesia. Following reduction, families completed a satisfaction survey regarding mode of anesthesia and overall care (rated 0–10, with 10 being the best score) and an assessment of discomfort (rated 0–10, with 0 being no pain). Length of stay in the emergency department (ED) and complications related to procedure and method of anesthesia were recorded. Radiographic alignment was evaluated before and after reduction. Results Twenty-six patients underwent reduction with either PS or HB. Midazolam was used in addition to HB in 8 patients. One patient was converted from HB to PS due to inadequate block. There was no significant difference in prereduction and postreduction angulation between the groups, and reductions maintained satisfactory alignment. Overall satisfaction and satisfaction with anesthesia were excellent for both groups, with respective means of 9.5 and 9.5 for PS and 9.3 and 9.6 for HB. Patient discomfort was minimal in both groups, with a mean of 1.6 for PS and 2.2 for HB. Length of stay was significantly shorter for HB patients, with patients spending a mean of 2.2 hours less in the ED. Three patients required further intervention following initial reduction. One patient in each group required revision reduction, and 1 PS patient underwent closed reduction and pinning. Conclusions Use of HB for the reduction of pediatric DRFs provided radiographic alignment, patient satisfaction, and pain control comparable with that of PS, while significantly decreasing ED time and resources. Type of study/level of evidence Therapeutic II.
RF Power Systems for the National Synchrotron Light Source

The booster synchrotron and the two storage rings at the NSLS are provided with rf power systems of 3 kW, 50 kW, and 500 kW nominal output power, all at 53 MHz. This power is supplied by grounded grid tetrode amplifiers designed for television broadcast service. These amplifiers and associated power supplies, control and interlock systems, rf controls, and computer interface are described.
Increased frequency of formation of interphase ring-chromosomes in radiosensitive irs-1 cells exposed to X-rays.

Abstract Induction and rejoining of interphase chromosome breaks were measured, after expsure to X-rays, in plateau-phase Chinese hamster V79 cells and in a radiosensitive mutant cell line derived from them, irs -1, using premature chromosome condensation (PCC). There was no difference in the induction of interphase chromosome breaks per Gy between the radiosensitive mutant cells and wild-type V79 cells despite the large differences in their radiosensitivity; an induction of 2.85 ± 0.05 breaks/cell/Gy was measured in both cell lines. Also, rejoining of interphase chromosome breaks proceeded in the two cell lines with similar kinetics ( t 1 2 = 26.2 min ). In contrast. ring chromosomes formation was higher in irs -1 cells, as compared to wild-type V79 cells (0.78 versus 0.44 after 6 h of repair). These results confirm previous observations suggesting that a general deficiency in the rejoining of DNA dsb is unlikely to be a direct cause of the increased radiosensitivity of irs -1 cells, and are consistent with the hypothesis that the increased radiosensitivity of these cells derives from an increase in the probability of misrepair.
Responses of crayfish photoreceptor cells following intense light adaptation.

After intense orange adapting exposures that convert 80% of the rhodopsin in the eye to metarhodopsin, rhabdoms become covered with accessory pigment and appear to lose some microvillar order. Only after a delay of hours or even days is the metarhodopsin replaced by rhodopsin (Cronin and Goldsmith 1984). After 24 h of dark adaptation, when there has been little recovery of visual pigment, the photoreceptor cells have normal resting potentials and input resistances, and the reversal potential of the light response is 10–15 mV (inside positive), unchanged from controls. The log V vs log I curve is shifted about 0.6 log units to the right on the energy axis, quantitatively consistent with the decrease in the probability of quantum catch expected from the lowered concentration of rhodopsin in the rhabdoms. Furthermore, at 24 h the photoreceptors exhibit a broader spectral sensitivity than controls, which is also expected from accumulations of metarhodopsin in the rhabdoms. In three other respects, however, the transduction process appears to be light adapted: (i) The voltage responses are more phasic than those of control photoreceptors. (ii) The relatively larger effect (compared to controls) of low extracellular Ca++ (1 mmol/1 EGTA) in potentiating the photoresponses suggests that the photoreceptors may have elevated levels of free cytoplasmic Ca++. (iii) The saturating depolarization is only about 30% as large as the maximal receptor potentials of contralateral, dark controls, and by that measure the log V-log I curve is shifted downward by 0.54 log units. The gain (change in conductance per absorbed photon) therefore appears to have been diminished.
Sedimentation and Reef Development in Turbid-Water Areas of Fanning Lagoon: ABSTRACT

The term "coral reef" invokes, for most people, a vision of clear-water tropical seas. The clear water of this vision is not necessarily true. In Fanning Island Lagoon (3°54^primeN, 159°20^primeW) extensive thickets of Acropora and muddy sediments coexist at depths of 35 ft in water so turbid that a diver is not visible for more than 10-15 ft. Three narrow passes connect the lagoon with the open ocean. A network of linear reefs divides the lagoon into several nearly isolated ponds. Lagoon waters are turbid except for an area around 1 of the passes. Coral abundance in the turbid-water area does not differ markedly from that in the clearer water. However, the corals of the clear water are mostly massive forms, while the turbid-water corals are ramose. Lush coral growth is present along the sides of the linear reefs as well as in thickets in the interreef ponds. Linear reefs wider than about 50 ft have medial sand areas and there is a medium- to coarse-grained sand in the ponds along the reef edges. However, the major sediment in the lagoon is medium silt. The sediment particles are the result of physical and biologic abrasion of corals, mollusks, and calcareous red algae. Unlike many lagoons, Foraminifera and Halimeda are not important sediment contributors in Fanning Lagoon. End_of_Article - Last_Page 867------------
Free standing yttria-doped zirconia membranes: Geometrical effects on stability

Professor Arthur Nowick made seminal contributions to the areas of ionic conduction mechanisms in crystalline and disordered systems. An area of emerging interest in the solid state ionics community is investigating conduction in the mesoscopic regime. With free standing membranes, one can probe low-dimensional effects such as confinement without interference from substrates. Membranes have potential relevance to solid state devices that benefit from reduced ionic resistance, for example sensors and solid oxide fuel cells. Membranes with varying lateral dimensions have been previously reported in literature; however, understanding of stress interactions in suspended oxide structures is in early stages. In this paper, we demonstrate self-supported, i.e. in the absence of any additional mechanical support layers, square and circular membranes of 100 nm thick yttria-doped zirconia (YDZ) having side length and diameters of 0.15–2 mm. The buckled membrane shape is intimately linked to the fabrication processes arising from dry versus wet etching protocols. Geometrical considerations associated with buckling and stability are discussed. Thin film solid oxide fuel cells utilizing circular membranes are fabricated, exhibiting open circuit voltages between 0.8 and 1 V that correlate with membrane size and exhibit a total power output on the order of several mW. These results contribute to advancing experimental techniques to fabricate free standing oxide membranes for fundamental and applied studies pertaining to ionic and electronic conduction.
Learning and inferring a semantic space from user's relevance feedback for image retrieval

As current methods for content-based retrieval are incapable of capturing the semantics of images, we experiment with using spectral methods to infer a semantic space from user's relevance feedback, so the system will gradually improve its retrieval performance through accumulated user interactions. In addition to the long-term learning process, we also model the traditional approaches to query refinement using relevance feedback as a short-term learning process. The proposed short- and long-term learning frameworks have been integrated into an image retrieval system. Experimental results on a large collection of images have shown the effectiveness and robustness of our proposed algorithms.
Synthesis of 3′‐deoxy‐3′‐[18F]fluoro‐1‐β‐D‐xylofuranosyluracil ([18F]‐FMXU) for PET

The synthesis of a pyrimidine analog, 3′-deoxy-3′-[18F]-fluoro-1-β-D-xylofuranosyluracil ([18F]-FMXU) is reported. 5-Methyluridine 1 was converted to its di-methoxytrityl derivatives 2 and 3 as a mixture. After separation the 2′,5′-di-methoxytrityluridine 2 was converted to its 3′-triflate 4 followed by derivatization to the respective N3-t-Boc product 5. The triflate 5 was reacted with tetrabutylammonium[18F]fluoride to produce 6, which by acid hydrolysis yielded compound 7. The crude preparation was purified by HPLC to obtain the desired product [18F]-FMXU. The radiochemical yields were 25–40% decay corrected (d. c.) with an average of 33% in four runs. Radiochemical purity was >99% and specific activity was >74 GBq/µmol at the end of synthesis (EOS). The synthesis time was 67–75 min from the end of bombardment (EOB). Copyright © 2005 John Wiley & Sons, Ltd.
Thermal conductivity and expansion of cross-ply composites with matrix cracks

Abstract Theoretical models are developed for heat conduction and thermal expansion in a fiber-reinforced ceramic cross-ply laminate containing an array of parallel transverse matrix cracks. Two stages of the transverse matrix cracks are considered: Stage-I with tunnel cracks in the 90 ° plies aligned parallel to the fibers, and Stage-II with cracks extended across both the 90 and 0 ° plies with intact fibers bridging the matrix in the 0 ° plies. The effect of debonded fiber-matrix interfaces in the 0 ° plies is also considered in Stage-II. Approximate closed form solutions for the overall in-plane thermal conductivities and coefficients of thermal expansion (CTEs) as functions of matrix crack spacing and constituent properties are obtained using an approach which combines an analysis akin to a shear-lag analysis with finite element results. Emphasis is placed on the important class of composites whose fiber expansivity is smaller than that of the matrix. For this class, matrix cracking and interfacial debonding results in reduced thermal expansivity. Interfacial debonding has a significant effect on both longitudinal conductivity and thermal expansivity, especially the latter. Comparisons between the present model predictions and numerical and experimental results are provided where these are available.
Accuracy of Trip Durations Reported by Marine Sport‐Boat Fishermen

Abstract The Texas Parks and Wildlife Department (TPWD) conducted surveys to determine the accuracy of trip durations reported by marine sport-boat fishermen. The surveys were conducted at boat ramps on 21 d during May-August 1982. The fishermen's reported trip duration (nearest 0.5 h) was compared to TPWD's observed trip duration (nearest 0.1 h). No significant differences were found between the reported and observed trip durations by sport-boat fishermen. Eighty-six percent of all differences between reported and observed trip durations were within ± 1.0 h of zero, and 68% of those differences were within the precision desired (nearest 0.5 h). Therefore, the mean trip duration reported by sport-boat fishermen during 1-d fishing trips is an empirically unbiased estimate of actual mean trip duration. The accuracy of trip duration reported by sport boaters was not influenced by the actual trip length.
Calibration of corn response to bray I, bray II, and Mehlich II extractable soil phosphorus

Abstract Calibration of field crop response to nutrient availability is the basis for making a fertilizer recommendation from a soil test. A field experiment was established in 1981 to calibrate corn (Zea mays L.) yield to extractable soil P level on a Mexico silt loam soil (Udollic Ochraqualf) near Columbia, Missouri. A single application of P fertilizer was surface broadcast in 1981 at five rates (0, 82, 163, 244, and 328 kg P ha‐1). No further P application was made for the duration of the study. Soybean (Glycine max. L.) was planted in 1981, and three commercial corn hybrids were planted in 1982 and 1983. The corn hybrids included ‘Trojan 115A (SX)’, ‘Agway 849X’, and ‘Stauffer 114+ ‘. Higher overall grain yields in 1982 than 1983 were attributed to more favorable weather conditions in 1982 as well as to declining residual soil P availability. Trojan hybrid was the highest grain producer in 1983, while no yield differences among hybrids occurred in 1982. Leaf P concentrations increased with P rate in ...
Ritualized Submission and the Reduction of Aggression in an Invertebrate

Ritualized behaviors that signify acceptance of a dominance relationship and reduce aggression between rivals are a common feature of vertebrate social behavior. Although some invertebrates, including crayfish, lobsters, and ants, display dominance postures, more complex dominance rituals and their effects on fitness have not been reported. We found that crayfish display such a complex ritual, when two males engaged in pseudocopulatory behavior to signify their dominance relationship. This was followed by a reduction in aggression and an increased likelihood of the subordinate's survival. Pseudocopulation was initiated by the eventual dominant and could be accepted or refused by the eventual subordinate. The frequency of aggressive behavior declined significantly during the first hour in all pairs that pseudocopulated but remained high in pairs that did not. Whereas all the subordinate members of pairs that pseudocopulated survived the initial 24 hr of pairing, half of subordinates that did not pseudocopulate were killed during that time. This differential mortality indicates that the reduction of aggression induced by the pseudocopulatory ritual directly enhances the differential survival of male crayfish that engage in this behavior.
Hillslope Runoff and Soil Erosion Following Reforestation in the Copper Basin, Tennessee, USA

The landscape of the 130 km2 Copper Basin, in the southeastern USA, became extremely degraded during more than a century of logging, mining, acidification, grazing, and fire. In the twentieth century, the Copper Basin became the focus of a series of reforestation programs and is now largely tree-covered again. To investigate the effects of over 50 years of reforestation efforts, we developed a space-for-time substitution and conducted rainfall simulation experiments in ‘forest’ patches of various ages, at sites remaining unvegetated, and at forested reference sites outside the basin. At 59 sites, we monitored surface runoff and sediment detachment rates during 30-minute rainfall simulation experiments; and at 54 of those sites, we determined soil organic matter content. Then, we measured litter and observed soils at 25 of the sites, and measured soil respiration at a site in each age zone. The results demonstrate that soil erosion by sediment detachment decreases within a decade following reforestation. Recently reforested sites have soils with significantly less organic matter and have higher runoff rates than forests more than 50 years old. The long-term persistence of low infiltration rates suggests that, at sites where the A and B soil horizons and the biological health of the soil have been lost, restoration of the hydrologic function of a landscape by reforestation may require centuries.
Type 5 Adenylyl Cyclase Disruption Increases Longevity and Protects Against Stress

Mammalian models of longevity are related primarily to caloric restriction and alterations in metabolism. We examined mice in which type 5 adenylyl cyclase (AC5) is knocked out (AC5 KO) and which are resistant to cardiac stress and have increased median lifespan of approximately 30%. AC5 KO mice are protected from reduced bone density and susceptibility to fractures of aging. Old AC5 KO mice are also protected from aging-induced cardiomyopathy, e.g., hypertrophy, apoptosis, fibrosis, and reduced cardiac function. Using a proteomic-based approach, we demonstrate a significant activation of the Raf/MEK/ERK signaling pathway and upregulation of cell protective molecules, including superoxide dismutase. Fibroblasts isolated from AC5 KO mice exhibited ERK-dependent resistance to oxidative stress. These results suggest that AC is a fundamentally important mechanism regulating lifespan and stress resistance.
Self-Consistent Local Orbitals for NaCl, NaBr, KCl, and KI

Using the Adams-Gilbert local-orbitals theory, accurate to first order in interatomic overlap, it has been possible to obtain self-consistent local orbitals for several fcc alkali halide crystals. In this paper, results are reported for NaCl, NaBr, KCl, and KI. In this calculation, nearest neighbors are considered exactly while more distant neighbors are considered in a point-ion model. The method of Roothaan is used to obtain the results. All relativistic effects are neglected in this calculation.
Work in progress — Connecting veterans to customized engineering education at the University of San Diego

In 2008, the Post-9/11 GI Bill was passed to improve the educational opportunities available for military veterans. Along with increased financial support, the Yellow Ribbon Program was created to make it easier for veterans to afford private colleges and universities. At the same time, the National Science Foundation and other agencies are recognizing a critical shortage of engineers. This paper describes the measures being taken at USD to provide customized undergraduate engineering education opportunities for Post-9/11 veterans. The immediate goals of the project are 1) to develop strategies for recruiting veterans into engineering fields, 2) to determine how military experiences and education can be recognized by the university, 3) to identify the unique support services needed to best assure veteran student success, and 4) to identify internship and summer research experiences that can provide additional financial support to the students. The scope of the project requires collaboration from across campus including academic faculty and staff and supporting administrative areas ranging from the Registrar, to Counseling, to Housing. The results of this project will help other universities attract veterans as new students, and graduate them as engineers.
Using the fold point to analyze mental rotation data: A second look

This experiment was designed to examine some of the characteristics of the estimated fold point in a mental rotation task. Thirty males performed a mental rotation task for approximately 1 h on each of 5 consecutive days. Each day was divided into an early and late session. Fold points were estimated for each session for both standard and mirror responses on a subject-by-subject basis. Standard and mirror responses had significantly different estimated fold points, which were unaffected by practice. The test-retest reliability for successive sessions was moderate for both standard and mirror responses and also appeared unaffected by practice.
Stator Endwall Leading-Edge Sweep and Hub Shroud Influence on Compressor Performance

Etude experimentale de l'utilisation de la courbure du bord d'attaque du stator pour ameliorer les performances d'un compresseur a ecoulement axial. Examen de l'aerodynamique de trois conditions de moyeu de stator (diametre interieur)
Quizzing and Feedback in Computer-Based and Book-Based Training for Workplace Safety and Health.

Abstract Participants received different amounts of information in either a cTRAIN computer-based instruction (CBI) program or in a booklet format, presented before or concurrently with interactive questions about the information. An interactive CBI presentation that required an overt response during training produced equivalent acquisition and retention to showing questions with the correct answers underlined in a book. “Open book tests” proved to be an effective teaching strategy, compared to requiring overt responses on tests in a CBI format. Retention did not prove durable over 1 week or 1 month in any format. These results confirm and extend research in college populations to adults in the workforce and raise serious concerns about the durability of workplace safety and health training beyond an immediate post-training test.
Delayed sleep phase cases and controls

Background: Delayed sleep phase disorder (DSPD) is a condition in which patients have difficulty falling asleep before the early morning hours and commonly have trouble awakening before late morning or even early afternoon. Several studies have suggested that variations in habitual bedtime are 40–50% heritable. Methods: We recruited a case series of 205 participants, along with 221 controls (DSPD-C) with normal sleep, roughly matched for age, gender, and ancestry. A representative sample of San Diego adults recruited some years before was already available to confirm the control group. Both DSPD and DSPD-C provided blood or saliva samples for DNA and completed extensive questionnaires about sleep habits, sleep history, family history, sleep quality, morningness-eveningness traits, depression, mania, and seasonality of symptoms. The DSPD group wore wrist actigraphs for a median of 13.2 days. The representative sample collected previously had undergone actigraphic recordings, from which 48 hours of data were generally available. Results: The DSPD and DSPD-C samples showed almost no overlap on morningness-eveningness scores. DSPD cases went to bed and arose about 3 hours later than the DSPD-C and the representative sample. DSPD cases reported more difficulties with sleep, poorer sleep quality, and more depression, but there was no significant difference in a history of mania. DSPD cases reported more family history of late bedtimes, but female DSPD reported that their fathers' bedtimes were later than the fathers of male DSPD. Conclusion: These results indicate a DSPD phenotype is familial and associated with unipolar depression.
Resistive Training Improves Insulin Sensitivity after Stroke

Background Insulin resistance is highly prevalent after stroke, contributing to comorbid cardiovascular conditions that are the leading cause of death in the stroke population. This study determined the effects of unilateral resistive training (RT) of both the paretic and nonparetic legs on insulin sensitivity in stroke survivors. Methods We studied 10 participants (mean age 65 ± 2 years; mean body mass index 27 ± 4 kg/m 2 ) with hemiparetic gait after remote (>6 months) ischemic stroke. All subjects underwent 1-repetition maximum (1-RM) strength testing, 9 had an oral glucose tolerance test (OGTT), and 7 completed a 2-hour hyperglycemic clamp (with glucose elevation targeted at 98 mg/dL above baseline fasting level) before and after 12 weeks (3×/week) of progressive, high repetition, high-intensity RT. Body composition was assessed by dual-energy x-ray absorbtiometry in all participants. Results Leg press and leg extension 1-RM increased in the paretic leg by 22% ( P P P P = .18). There was also no change in glucose AUC. First-phase insulin response during the hyperglycemic clamp (0-10 minutes) decreased 24% ( P P P Conclusions These findings provide the first preliminary evidence that RT may reduce hyperinsulinemia and improve insulin sensitivity after disabling stroke.
Package stacking in SMT for 3D PCB assembly

The need for continued miniaturization, functional densification and integration in handheld electronics products provides the strong incentive for printed circuit board (PCB) assembly in three-dimensions (3D). One way to accomplish 3D assembly is through the use of die stacking in chip scale packages (CSP), where the dice are stacked internally in the package. The other way to accomplish 3D assembly is through the use of package stacking. This is the process where two packages are placed on top of each other during the traditional surface mount placement process and then soldered together during the SMT (surface mount technology) reflow. In this paper, package stacking as part of the SMT process is described. The process, materials, and solder joint formation are characterized, and key issues highlighted.
Repeated cocaine decreases the avoidance response to a novel aversive stimulus in rats.

Rationale. Stress interacts with cocaine to produce enhanced neurochemical and behavioral responding to cocaine; however, few studies have examined unconditioned behavioral responses to aversive stimuli after repeated cocaine.
Correlation of steel corrosion in pipe flow with jet impingement and rotating cylinder tests

Abstract The relationship of laboratory fluid flow corrosion test techniques to flow-accelerated corrosion in field applications and the parameters required to apply laboratory data effectively in the field were studied. Single-phase, aqueous, sweet corrosion of steel in turbulent pipe flow (12.7 mm and 25.4 mm diam) was correlated to corrosion in jet impingement and rotating cylinder tests. All tests were conducted simultaneously, using the same test fluid to minimize environmental variables and to allow a direct, realistic comparison of test methods. Rotating cylinder electrode corrosion rates did not correlate with pipe flow based on wall shear stress or mass transfer for flow-accelerated corrosion of carbon (C) steel in the environment studied. Jet impingement corrosion rates for the test ring at r/r0=3 correlated with pipe flow based on wall shear stress. The general equation for flow-accelerated corrosion of C steel under turbulent flow conditions in this environment was expressed as: Rcorr = a τwb ...
Seismic Performance of Steel Girder Bridges with Ductile Cross Frames Using Single Angle X Braces

Ductile end cross frames have been proposed in the past as a seismic design and retrofit strategy for steel plate girder bridges. In this paper it is shown that with good connection details, single angles are able to undergo large cyclic deformations in excess of 6% average axial strain before failure occurs. Large-scale shake table experiments were performed on a straight steel I-girder bridge model to evaluate the performance of a superstructure with ductile end cross frames using single angle X braces. The cross frames exhibited no apparent overall strength degradation, but also a comparatively low postyield stiffness, allowing the cross frames to act as effective structural fuses. The measured base shear was 61% of the elastic base shear in response to 2.0 times the El Centro earthquake at an average drift of 3.4%. Large girder drifts were achieved without distress in the deck slab by removing selected studs between the slab and top flange of the girders at the end cross frame locations, with axial deformations in the angles well below their deformation capacity based on component experiments.
Dynamic loosening of threaded fasteners

A study on loosening of threaded fasteners subjected to dynamic shear loads is presented. A fundamental analysis of loosening reveals that a fastener can loosen at lower loads than previously expected due to localized slip at the contact surfaces. Four different loosening processes of a screw under different conditions of slip at the head and thread contact regions are identified. Experimental results illustrating these loosening processes are presented.
Adverse effects of chronic circadian desynchronization in animals in a "challenging" environment

Continuous disruption of circadian rhythms, as seen in human shift workers, has been associated with the development of a number of adverse mental and physiological conditions. However, scientific evidence linking circadian disruption to overall health, particularly in animal models, is not well documented. In this study, we have demonstrated that exposing C57BL/6J mice to 12-h phase shifts every 5 days for 3 mo had no effect on body weight or intestinal physiology. However, when animals were further challenged with dextran sodium sulfate to induce colitis, chronic shifting of the light-dark cycle led to a dramatic increase in the progression of the colitis as indicated by reduced body weight, abnormal intestinal histopathology, and an exacerbated inflammatory response. These data indicate that circadian disruption is an important predisposing factor that may provoke the onset or worsening of various disease states such as inflammatory disorders. This study provides further evidence for continued investigations using animal models of circadian disruption to examine the consequences of circadian disruption on health when organisms are faced with a “challenging” environment.
Comparison of pedigreed and nonpedigreed randombred control systems for use with artificial selection in the Japanese quail.

Abstract The performance characteristics of six replicate sublines of a randombred control, three pedigreed (P) and three nonpedigreed (NP), were studied to see if the NP mating system could be used as a method for maintaining a randombred control for selection experiments. Each subline was maintained with 32 single-pair matings, with 64 offspring placed each generation for each line. Brother × sister matings were avoided in the P but not in the NP system. The NP chicks were pedigreed in order to determine the exact numbers of brother × sister matings selected in that system, but pedigrees were not considered during selection. Records were collected on the numbers of matings producing offspring, the expected rate of inbreeding based on the effective population size, hatchability, egg production, egg weight, and the body weights of the males and females. Replicate lines in the P system had more matings that produced viable offspring, which resulted in larger effective population sizes, lower rates of inbreeding, and smaller average family sizes than those in the NP system. A number of significant differences were found between means of the replicate lines within system and between regressions of the traits measured in the individual lines on generation number. Most of these differences disappeared when the data from the three replicates within mating system were pooled and compared, suggesting that differences found between lines within system were due to random genetic drift due to restrictions in population size. It is suggested that the NP system can be used as an effective control procedure for Japanese quail breeding experiments, but that more than 32 mating pairs should be used for its maintenance in order to reduce the amount of genetic drift within the control population.
Borrowed-virtual-time (BVT) scheduling: supporting latency-sensitive threads in a general-purpose scheduler

Systems need to run a larger and more diverse set of applications, from real-time to interactive to batch, on uniprocessor and multiprocessor platforms. However, most schedulers either do not address latency requirements or are specialized to complex real-time paradigms, limiting their applicability to general-purpose systems.In this paper, we present Borrowed-Virtual-Time (BVT) Scheduling, showing that it provides low-latency for real-time and interactive applications yet weighted sharing of the CPU across applications according to system policy, even with thread failure at the real-time level, all with a low-overhead implementation on multiprocessors as well as uniprocessors. It makes minimal demands on application developers, and can be used with a reservation or admission control module for hard real-time applications.