cssi/SciSciGPT-SciSciNet huggingface dataset:
Stable cluster formation in aqueous suspensions of iron oxyhydroxide nanoparticles.

Metal oxide and oxyhydroxide nanoparticles are important components of natural aqueous systems and have application in photocatalysis. Uncoated (oxyhydr)oxide nanoparticles can form charge-stabilized colloids in water, but the precise regimes of dispersion and aggregation have been determined for very few nanomaterials. We studied the colloidal behavior of ∼6 nm nanoparticles of iron oxyhydroxide (FeOOH), a common natural nanoscale colloid, and found that these nanoparticles formed stable suspended clusters under a range of aqueous conditions. Light and X-ray scattering methods show that suspended fractal nanoclusters are formed between pH 5 and 6.6 with well-defined maximum diameters that can be varied from 25 nm to approximately 1000 nm. The nanoclusters retain a very high surface area, and persist in suspension for at least 10 weeks in solution. The process is partially reversible because optically transparent suspensions are regained when nanoparticles that aggregated and settled at pH >7 are adjusted to pH 4 without stirring. However, completely redispersed nanoparticles are not obtained even after one month. Because nanocluster formation is controlled predominantly by surface charge, we anticipate that many metal oxide and other inorganic nanoparticles will exhibit equivalent cluster-forming behavior. Our results indicate that natural nanoparticles could form stable nanoclusters in groundwater that are likely to be highly mobile, with implications for the long-range transport of surface sorbed contaminants.
POTENTIAL EFFECTS OF BANDING AS A FUNCTION OF TEST RELIABILITY

Cascio, Outtz, Zedeck, and Goldstein (1991) described the application of a number of test score banding procedures in personnel selection. Equations are developed illustrating the relationship between the width of test score bands and test reliability. When reliability is moderate to low, bands are likely to be larger than the standard deviation of the test, and are likely to include a large proportion of the applicant pool. The relationships between band widths and the differences between higher scoring and lower scoring groups are also examined. When the band is smaller than the differences between groups (which may happen when highly reliable tests are used), banding may not by itself prove effective as a means of reducing the adverse impact of tests, even when banding systems that maximize opportunities for members of the lower scoring group are used.
Fluxless Sn–Ag bonding in vacuum using electroplated layers

Abstract A fluxless bonding process in vacuum environment using newly developed electroplated Sn–Ag multilayer structure at eutectic composition is presented. The new bonding process is entirely fluxless, or flux-free. It is performed in vacuum (100 mTorr), in which the oxygen content is reduced by a factor of 7600 comparing to air, to inhibit solder oxidation. In the design, Cr/Au dual layer is employed as the UBM as well as the plating seed layer. This UBM design, seldom used in the electronic industry, is explained in some details. To realize the fluxless possibility, a proper layer design of the solder structure is needed. In this connection, we wish to point out that it is hard to achieve fluxless bonding using Sn-rich alloys because these alloys have numerous Sn atoms on the surface that are easily oxidized. To prevent Sn oxidation, a thin Ag layer is plated immediately over Sn layer. XRD results confirm that this thin Ag layer does act as a barrier to prevent oxidation of the inner Sn layer. The resulting solder joints are void free as examined by a scanning acoustic microscope (SAM). SEM and EDX studies on the cross section of the joint indicate a homogeneous Sn-rich phase. The melting temperature is measured to be between 219 and 226 °C. This new fluxless bonding process is valuable in many applications where the use of flux is prohibited.
Correlation of the subsurface Lower and Middle Devonian of the Lake Erie region: Alternative interpretation and reply

No Abstract Available. The article about which this alternative interpretation was written appeared in the Bulletin , v. 95, p. 814–828.
End product inhibition of hepatic 25-hydroxyvitamin D production in the rat: specificity and kinetics.

Abstract The role of vitamin D metabolites in the regulation of hepatic 25-hydroxyvitamin D production was investigated by examining the effects of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D on the synthesis of [25- 3 H]hyroxyvitamin D by rachitic rat liver homogenates. Production of [25- 3 H]hydroxyvitamin D was inhibited by 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, but not by 24,25-dihydroxyvitamin D. 25-Hydroxyvitamin D increased the K m of the vitamin D-25-hydroxylase enzyme(s), while 1,25-dihydroxyvitamin D decreased the V max with a K i of 88.7 ng/ml. Inhibition of hepatic 25-hydroxyvitamin D production by 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D may be another control mechanism to regulate circulating vitamin D levels.
Optical Characteristics Of Windblown Dust

Naturally occurring or windblown dust causes periods of low visibility, particularly in arid regions, and can be a source of obscuration of electro-optical devices operating in the visible or infrared spectral regions. Occurrence of windblown dust and factors influencing the injection of soil into the atmosphere by the wind are described. Characteristics of the dust affecting atmospheric optical properties discussed include particle number density, particle size distributions, and complex index of refraction. The ways that variations of these characteristics affect the transmission of visible and infrared energy are described.
Associations of pentraxin-3 with cardiovascular events, incident heart failure, and mortality among persons with coronary heart disease: Data from the Heart and Soul Study

Background Pentraxin-3 (PTX3) is an inflammatory marker thought to be more specific to vascular inflammation than C-reactive protein (CRP). Whether PTX3 is independently associated with adverse events among persons with stable coronary heart disease (CHD), independently of CRP, and whether kidney dysfunction influences these associations are not known. Methods We evaluated the associations of baseline PTX3 levels with all-cause mortality, cardiovascular (CV) events (myocardial infarction, stroke, or CHD death), and incident heart failure (HF) during 37 months among ambulatory persons with stable CHD participating in the Heart and Soul Study. Cox proportional hazards models were adjusted for age, sex, race, hypertension, diabetes, smoking, and CRP. Results Among 986 persons with stable CHD, each 1 unit increase in log PTX3 at baseline was associated with an 80% increased risk of all-cause mortality (hazard ratio [HR] 1.8, 95% CI 1.5-2.1), a 50% increased risk of CV events (HR 1.5, 95% CI, 1.2-1.9), and an 80% greater risk of incident HF (HR 1.8, 95% CI, 1.3-2.5). Further adjustment for estimated glomerular filtration rate (eGFR) attenuated these associations to 1.6 (1.3-1.9) for mortality, 1.3 (1.0-1.6) for CV events and 1.5 (1.1-2.1) for incident HF. Stratification by eGFR >60 mL/min per 1.73m 2 or 2 did not affect these associations ( P interaction > .3 for all outcomes). Conclusions Among persons with stable CHD, higher PTX3 concentrations were associated with increased risk for all-cause mortality, CV events, and incident HF independently of systemic inflammation. Adjustment for eGFR modestly attenuated these associations, suggesting that future studies of PTX3 should adjust for kidney function.
Using a Think-Aloud with Diverse Students: Three Primary Grade Students Experience Chrysanthemum

Many struggling readers, students with English as a second language, and children with disabilities do not engage in the strategies that good readers use when reading for understanding. Reading comprehension depends upon the students’ ability to successfully use strategies to monitor and control their own comprehension. Teachers need to help students develop skills that will aid in reading comprehension. The think-aloud is one strategy that can help struggling readers improve fluency and comprehension. One of the most important components to determine the success of the think-aloud is the teacher’s ability to model and facilitate the think-aloud procedure. The teacher needs to have a basic understanding of what is meant to be accomplished using this method. This article profiles how three teachers model and facilitate a think-aloud with three struggling readers.
Generalized Langevin equation approach to higher-order classical response: second-order-response time-resolved Raman experiment in CS2

A simple, systematic generalized Langevin equation approach for calculating classical nonlinear response functions is formulated and discussed. The two-time Poisson brackets appearing at second and higher order are rendered tractable by a physically motivated approximation. The method is used to calculate the fifth order (second order response) Raman response of liquid CS2. Agreement with simulation is good, but the simplicity of the theoretical expression suggests that the path to obtaining qualitatively new information about liquids with the fifth order experiment is uncertain. Further applications of the basic approach are suggested.
Effect of a single irrigation at different reproductive growth stages on soybean planted in early and late June

When subsurface irrigation sources are lacking, storage of precipitation in farm ponds and lakes may provide a source for irrigation, but the amount of water available may be limited. Deficit irrigation at selected growth stages may help avoid crop stress at critical times. The objective of this study was to determine the effect of timing of a single irrigation on soybean cultivars planted at two dates. The experiment was conducted from 1987 to 1990 on a Parsons silt loam (fine, mixed, thermic Mollic Albaqualf) near Parsons, Kansas. The experiment was designed as a split-plot with the eight whole plots being a factorial arrangement of irrigation treatments and planting dates and subplots were soybean [Glycine max (L.) Merr.] cultivars. The four irrigation treatments were: (1) no irrigation, (2) 2.5 cm at growth stage R1 to R2 (beginning to full bloom), (3) 2.5 cm at R4 (full pod), and (4) 2.5 cm at R6 (full seed). The two planting dates were early and late June. The three, maturity group IV, soybean cultivars were Crawford, Douglas, and Sparks. In the less stressful years, 1987 and 1989, yield was unaffected by irrigation when soybean cultivars were planted in early June, but irrigation increased yield of late-June-planted soybean by 0.4 Mg ha–1 or more. In 1988 and 1990, climatic conditions were dry and hot. This resulted in low yields, but regardless of planting date, soybean responded to irrigation applied at any growth stage in 1988 and at R6 in 1990. Yield increases from irrigation appear to be more related to increasing seeds per plant than seed weight. Selection of the timing of a single irrigation between growth stages R1, R4, and R6 may not result in large yield differences because all increased the number of seeds per plant. Irrigation at R6 also increased average seed weight. With typical weather conditions in the mid-latitude section of the eastern Great Plains, soybean planted in late June are more likely to benefit from a single irrigation than those planted in early June.
The immune system and memory consolidation: a role for the cytokine IL-1β

Interleukin-1 beta (IL-1beta), known to play a role in orchestrating the physiological and behavioral adjustments that occur during sickness, has also been shown to significantly influence memory consolidation. To support this assertion we present neurobiological evidence that the substrates for IL-1beta to influence memory processing and neural plasticity exist. We then present behavioral evidence that central IL-1beta administration and agents that induce central IL-1beta activity impair the consolidation of memories that depend on the hippocampal formation but have no effect on the consolidation of hippocampal-independent memories. Further, we demonstrate that the impairments in hippocampal-dependent memory consolidation produced by agents that induce IL-1beta activity are blocked by antagonizing the actions of IL-1beta. Finally, we discuss these data in terms of their implications for a physiological role of IL-1beta in memory consolidation processes and a potential role of IL-1beta in producing memory impairments associated with stress, aging, Alzheimer's disease, and AIDS related dementia complex.
Ethical Issues Relating to the Health Effects of Long Working Hours

Considerable research evidence has accumulated indicating that there is an increased likelihood for illness and injury among employees working in long-hour schedules and schedules involving unconventional shift work (e.g., night and evening shifts). In addition, studies show that fatigue-related errors made by employees working in these kind of demanding schedules can have serious and adverse repercussions for public safety. As the result of these concerns, new protective legislation is being advocated in the United States, for instance, to restrict the hours of work among nurses and other health-care professionals. This article reviews the history of concerns about long working hours and the current scientific evidence regarding their effects on workers’ health. The ethical implications of unconventional shift work and long work-hour schedules are considered. Relevant ethical considerations involve mandatory or unpaid overtime and the possibility of employer coercion, the political basis for government regulation of working hours, potential limits on voluntary assumption of risk, societal benefits accruing from the equitable distribution of available working hours, gender-based inequities related to working hours, and employer responsibilities for protecting individuals who are not employees from the spillover effects of demanding work schedules.
Retinal Pathology in GM1 Gangliosidosis, Type II

In lysosomal diseases, morphologic in­ volvement of ocular tissues is a well-known finding. The various forms of mucopolysaccharidoses chiefly affect the cornea and to a lesser degree the retina, whereas sphingolipidoses involve predominantly the retina, ac­ counting for the cherry-red spot which oc­ curs typically in Tay-Sachs disease, but also in other diseases of this group. Its discov­ ery by Tay in 1881 engendered continued interest in the investigation and led to the concept of cerebroretinal degenerations, with emphasis on neuronal pathology. Aside from GM2-gangliosidosis, neuronal ceroid-lipofuscinosis, metachromatic leukodystrophy and sphingomyelinosis, all mentioned by Cogan and Kuwabara, GMi-gangliosidosis or generalized gangliosidosis has also been shown to affect the retina. In the infantile form, or type I, cherry-red spots occur in about 50% of the patients, and in the reti­ nal cells specific lipid inclusions can be demonstrated by light and electron micros­ copy." This type also encompasses deposi­ tion of mucopolysaccharides in visceral or­ gans and in mesenchymal structures of the eye. The juvenile form, or type II, of GMigangliosidosis, however, does not appear to produce visceral organ involvement and is not accompanied by ophthalmoscopic abnor­ malities. The retinal neurons, nevertheless, may harbor excess gangliosides, presumably GMi, in the form of membranous cytoplasmic bodies (MCB) and of other types of secondary and tertiary lysosomes.
Abstract 4464: Genetic variants at chromosome 8q24, colorectal epithelial cell proliferation, and risk for incident, sporadic colorectal adenomas

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Three polymorphic sites at chromosome 8q24 (rs7837328, rs10808555, and rs6983267) have been associated with risk for colorectal adenomas. It was also previously reported that the rs6983267 single nucleotide polymorphism (SNP) may enhance Wnt signaling, which regulates cell proliferation. To investigate associations between the 8q24 variants and colorectal epithelial cell proliferation in the normal-appearing colorectal mucosa, as well as risk for colorectal adenoma, we analyzed data from a previously conducted pilot, colonoscopy-based case-control study of incident, sporadic colorectal adenoma among the White participants (n = 90 cases, 132 controls). Proliferation was measured in biopsies of the normal-appearing mucosa of the rectum, sigmoid colon, and cecum using immunohistochemistry for proliferating cell nuclear antigen (PCNA) and calculated as a labeling index averaged across all three colorectal sites. Each SNP was associated with risk for colorectal adenoma in the same direction as previously reported; the odds ratios (ORs) for those homozygous for the rs7837328, rs10808555, and rs6983267 risk alleles relative to those heterozygous or homozygous for the non-risk alleles combined were, respectively, 2.07 (95% confidence interval [CI] 1.07-3.97), 2.37 (CI 0.97-5.76), and 1.55 (CI 0.86-2.79). Colorectal epithelial cell proliferation tended to be higher among those homozygous for the risk alleles (alleles A, G, and G for SNPs rs7837328, rs10808555, and rs6983267, respectively) compared to those heterozygous or homozygous for the non-risk alleles combined; in the cases and controls combined, for those with the rs7837328 AA genotype proliferation was 6.7% higher (p = 0.40), for those with the rs10808555 GG genotype it was 16.5% higher (p = 0.12), and for those with the rs6983267 GG genotype it was 1.2% higher (p = 0.87). These preliminary findings, which are consistent with previously reported direct associations between genetic variants at chromosome 8q24 and risk for colorectal adenoma, suggest that the genetic variants may also be associated with higher levels of colorectal epithelial cell proliferation in humans, thus providing support for the hypothesis that 8q24 variants may increase risk via enhanced Wnt signaling. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4464. doi:1538-7445.AM2012-4464
Bermuda Carbonate Platform: Quantitative Analysis of Depositional Environments: ABSTRACT

The responses to attrition and redistribution of the skeletal elements of the major sediment-contributing taxa govern interpretation of the depositional environments of skeletal carbonate sediments. The sediments, biotas, and physical conditions of the Bermuda platform provide data for such an integrated interpretation. Inward from the margin of the Bermuda carbonate platform there is a succession of environments: (1) a reef-front terrace; (2) a reef tract; and (3) a shallow central lagoon. The southwestern half of the lagoon is characterized by reef flats and clusters of patch reefs; these subdivide the lagoon into small basins. The northeastern half occupies a single large basin. The beaches of the Bermuda Islands, a series of Pleistocene dune ridges on the southern edge of the platform, constitute a fourth environment. Carbonate muds are found on deeper bottoms in the more protected basins, molluscan-algal sands in the less protected basins and at the shallower depths, and coralline-foraminiferal-algal sands in the reef tract and reef-front terrace. Trend-surface analysis of sedimentary and biotic data (based on approximately 300 grab samples and supported by direct observations made by snorkeling and SCUBA diving), stratified according to depth, indicates a clear correlation with factors in the physical environment. The sediment textural parameters are related to those organisms contributing to the sediment and are related to the depositional environment by discriminant function and factor analysis. Artificial "sediment" obtained from the breakdown of hard parts of assemblages of Bermuda organisms in laboratory tumbling-barrel experiments compare closely with sediments on the platform. The sedimentary record is a product of (1) the ecologically controlled distribution of organisms, (2) the size distributions resulting from the breakdown of the hard parts of the major sediment contributors, (3) the sorting and transport of the skeletal detritus, and (4) the degree of mixing of sediments derived from different environments. End_of_Article - Last_Page 553------------
Development of RF MEMS phase shifters using polymer and ferroelectric thin film

High performance of RF MEMS phase shifters using polymer bridges and ferroelectric thin film has been demonstrated in this research. To reduce the operating voltage for the RF MEMS phase shifters, polymer bridges and ferroelectric thin film have been implemented. The phase shifter fabricated on a quartz substrate is capable of continuous change in phase up to about 90o (at 15 GHz) with a maximum actuation voltage of 20V. Using polymer as the bridge materials contributes to the reduction in actuation voltage due to their low Young's modulus.
Changes in the mode of Southern Ocean circulation over the last glacial cycle revealed by foraminiferal stable isotopic variability

Benthic foraminiferal oxygen and carbon isotopic records from Southern Ocean sediment cores show that during the last glacial period, the South Atlantic sector of the deep Southern Ocean filled to roughly 2500 m with water uniformly low in δ13C, resulting in the appearance of a strong mid-depth nutricline similar to those observed in glacial northern oceans. Concomitantly, deep water isotopic gradients developed between the Pacific and Atlantic sectors of the Southern Ocean; the δ13C of benthic foraminifera in Pacific sediments remained significantly higher than those in the Atlantic during the glacial episode. These two observations help to define the extent of what has become known as the ‘Southern Ocean low δ13C problem’. One explanation for this glacial distribution of δ13C calls upon surface productivity overprints or changes in the microhabitat of benthic foraminifera to lower glacial age δ13C values. We show here, however, that glacial–interglacial δ13C shifts are similarly large everywhere in the deep South Atlantic, regardless of productivity regime or sedimentary environment. Furthermore, the degree of isotopic decoupling between the Atlantic and Pacific basins is proportional to the magnitude of δ13C change in the Atlantic on all time scales. Thus, we conclude that the profoundly altered distribution of δ13C in the glacial Southern Ocean is most likely the result of deep ocean circulation changes. While the characteristics of the Southern Ocean δ13C records clearly point to reduced North Atlantic Deep Water input during glacial periods, the basinal differences suggest that the mode of Southern Ocean deep water formation must have been altered as well.
An Approximate Hotelling's T2 Test for Matched Group Designs with SPSS:

This paper describes the procedures that may be used to compute Hotelling's T2 for matched group designs using the RELIABILITY routine of SPSS. Modifications of a normal SPSS job necessary for the test are described. An example data set is used to illustrate the procedure.
Isolation of a mRNA instability sequence that is cis-dominant to the ompA stability determinant in Escherichia coli

Abstract Transcriptional fusions with ompA and bla have been used to identify a novel mRNA instability element. A 287-nucleotide (nt) sequence containing a repetitive extragenic palindrome (REP) from the chloramphenicol acetyltransferase (cat) gene was inserted into the 3' untranslated region (UTR) of the ompA gene. In one orientation, the insert had no effect on the half-life of the ompA-cat chimeric transcript. In the other orientation, however, the sequence functioned as a destabilizing element and was dominant to the 5′-UTR ompA and REP stability elements. The orientation-dependent effect of the instability sequence suggests that sequence rather than structure alone is important to the function of the instability determinant. In addition, the instability sequence also destabilized an ompA-bla fusion construct when fused to its 3′-UTR region. A sensitive RNA ligation/PCR amplification technique was developed and used to analyze RNA decay intermediates. The results indicated that degradation of the chimeric transcript initiated within the 287-nt inserted sequence.
Semicircular beam-scanning metamaterial antenna with magnetic slot feed

Metamaterials have enabled many new applications and devices since their introduction, with metamaterial-enhanced antennas as one of the primary examples. Here, we describe an extension of previous work for a reconfigurable beam-scanning antenna constructed from a dynamically switchable near-zero-index metamaterial by constructing the lens so as to restrict scanning to a 180° arc in the azimuthal plane by the addition of a PEC ground plane. This modified lens can then be excited by a magnetic slot aperture cut into a substrate-integrated waveguide. This lens, although having restricted functionality compared to the original, allows for reduced design and implementation complexity.
Communication at the Crossroads of Ecology, Development, and Education: The Tutorial Learning System of Columbia.

In his Nobel Peace Prize acceptance speech, Gore (2007) spoke about collective action to bring about major changes in the usage, protection, and management of the environment. Collective action requires communication among all, including traditionally marginalized populations such as Indigenous people, women, youths, and children. The wisdom of all is needed. Diverse viewpoints and knowledge need to mingle. However, mere coming together can result either in beneficial action or contentious debate. It is the nature of such communication and the values that guide it that are central to the outcome. This article explores the values that guide participatory communication and the contribution of local knowledge in the service of ecological sustainability and development. To do so, it describes an innovative educational program in Columbia, called the Tutorial Learning System, dedicated to developing the prerequisite capabilities.
Lignin yield maximization of mixed biorefinery feedstocks by organosolv fractionation using Taguchi Robust Product Design

Lignin, isolated from switchgrass (Panicum virgatum) and tulip poplar (Liriodendron tulipifera) using organosolv fractionation is currently being explored for its potential use in the production of value-added chemicals and bio-based polymers. Taguchi Robust Product Design (TRPD) was applied to maximize lignin yield from the fractionation process. The following four controllable design factors were used in the TRPD: process temperature (120 °C, 140 °C and 160 °C), fractionation time (56 and 90 min), sulfuric acid concentration (0.025 M, 0.05 M and 0.1 M), and feedstock type (switchgrass/tulip poplar chip ratios of 10/90, 50/50 and 90/10). Process noise was induced in the experiment by using either the mass- or volume-based feedstock charges of switchgrass and tulip poplar chips. A maximum mean lignin yield of 78.63 wt% and signal-to-noise ratio of 37.90 was found at a 90 min runtime, a process temperature of 160 °C, a sulfuric acid concentration of 0.1 M, and a feedstock composition of 10% switchgrass and 90% tulip poplar. Process temperature was the most significant factor that influenced lignin yield. This study may provide a pathway for industrialists and researchers interested in maximizing lignin yield in the organosolv fractionation process.
Discharge-rate dependence of refractory behavior of cat auditory-nerve fibers.

Abstract A descriptive model for auditory-nerve (AN) refractory periods is described. The model assumes that interspike intervals consist of a constant-length absolute refractory period (ARP), followed by random-length relative refractory period (RRP) and a random-length waiting time to the next spike. Both the RRP and waiting time are exponentially distributed. This model fits AN hazard functions sufficiently well to provide estimates of the ARP and RRP durations for each fiber. The ARP is found to be constant, independent of discharge rate, with mean value between 0.56 and 0.86 ms in data from 7 experiments. The RRP decreases in duration as discharge rate increases; RRP mean length is less than 2 ms in most cases. There is an additional, slow component of recovery, lasting 20–40 ms, which is not modeled. The variation in RRP with discharge rate is shown to be capable of accounting for the deviation of AN regularity from that predicted for a Poisson process. Finally, properties of peaks seen in hazard functions just at the end of the ARP are described; these peaks are not included in the model, but are shown to be especially prominent in low and medium spontaneous rate fibers.
Dextromethorphan reduces intravenous cocaine self-administration in the rat

Dextromethorphan is a widely used antitussive agent with non-competitive antagonistic effects at the excitatory amino acid receptors of the NMDA type. Since excitatory amino acid neurotransmission has been implicated in cocaine dependence, the aim of the present study was to evaluate the effects of acute systemic administration of dextromethorphan in rats trained to self-administer cocaine intravenously. The experiments were designed to evaluate the effects of dextromethorphan on responding for cocaine and cocaine reward magnitude. The hypothesis was that dextromethorphan could attenuate specific aspects of cocaine-seeking behavior thus providing a preclinical rationale for its clinical use. The results reported reveal that acute pretreatment with dextromethorphan (10-50 mg/kg i.p.) significantly reduced cocaine self-administration in rats self-administering the drug intravenously in a simple continuous reinforcement schedule. In addition, acute pretreatment with an effective dose of dextromethorphan (25 mg/kg) decreased cocaine self-administration in rats tested at various doses of cocaine (0.12-0.5 mg/injection). Finally, dextromethorphan (25 mg/kg) also reduced the absolute reward magnitude of cocaine as measured by responding for cocaine in a progressive ratio schedule. These results encourage further experimental and clinical studies to evaluate the potential use of dextromethorphan during various phases of the natural history of cocaine dependence in humans.
Performance analysis of a parabolic trough solar collector with a porous absorber receiver

Abstract The thermal performance of a parabolic trough solar collector with an innovative porous absorber receiver is investigated. A one-dimensional finite-difference computer program is used to compute steady-state fluid velocity and transient temperature distributions along the line of vertical symmetry near the midpoint of the collector. Parametric studies are conducted to determine the influence of mass flow rate, acceptance angle, receiver dimensions, and material properties on the thermal efficiency. Numerical results for thermal efficiency show the potential for marked improvement over commercially available parabolic trough collectors for a wide range of fluid outlet temperatures.
Dynamic Value Pricing on I-15 in San Diego: Impact on Travel Time and Its Reliability

Selected results are presented of the Traffic Study, one of 12 studies conducted by San Diego State University for the I-15 Congestion (Value) Pricing Project in San Diego, a 3-year demonstration. The focus is on the project's impact on travel times and their distribution on both the main lanes and the express lanes of I-15 for both ExpressPass and FasTrak phases of the project. Specifically addressed is the issue of reliability of on-time arrival enjoyed by the FasTrak subscribers and the high variability of travel times for the I-15 travelers who use only main lanes of I-15 for their commute. Examination of the ramp and freeway delays shows that in the worst-case scenario, FasTrak subscribers who use express lanes can save up to 20 min avoiding delay on the I-15 main lanes. This finding agrees with the drivers' perceptions about their time savings when using FasTrak. Travel-time changes during the duration of the project also are examined. There were substantial year-to-year changes in travel times alon...
Metropolitan-scale Transport and Dispersion from the New York World Trade Center Following September 11, 2001. Part I: An Evaluation of the CALMET Meteorological Model

Following the collapse of the New York City World Trade Center towers on September 11, 2001, Local, State and Federal agencies initiated numerous air monitoring activities to better understand the impact of emissions from the disaster. A study of the estimated pathway that a potential plume of emissions would likely track was completed to support the U.S. EPA’s initial exposure assessments. The plume from the World Trade Center was estimated using the CALMET-CALPUFF dispersion modeling system. The following is the first of two reports that compares several meteorological models, including the CALMET diagnostic model, the Advanced Regional Prediction System (ARPS) and 5th Generation Mesoscale Model (MM5) in the complex marine-influenced urban setting of NYC. Results indicate wind speed, in most cases, is greater in CALMET than the two mesoscale models because the CALMET micrometeorological processor does not properly adjust the wind field for surface roughness variations that exits in a major built-up urban area. Small-scale circulations, which were resolved by the mesoscale models, were not well simulated by CALMET. Independent wind observations in Lower Manhattan suggest that the wind direction estimates of CALMET possess a high degree of error because of the urban influence. Wind speed is on average 1.5 ms−1 stronger in CALMET than what observations indicate. The wind direction downwind of the city is rotated 25–34 clockwise in CALMET, relative to what observations indicate.
MODELING RICE GRAIN YIELD RESPONSE TO NITROGEN FERTILIZATION FOR DELAYED-FLOOD PRODUCTION

Nitrogen (N) fertilization decisions are important for farm profit and environmental stewardship. The objective of this research was to evaluate and compare three models (linear-plateau, quadratic-plateau, and quadratic) that can potentially be used to describe rice yield response to N fertilization. Fertilizer N response trials of four newly released rice cultivars from seven sites located in both Mississippi and Louisiana over a two-year period were used. Similar R2 values indicated that each model fit the data equally well. The linear-plateau model had a tendency to produce lower estimates of the economical optimum N rate (EONR) while providing high estimates of yield at the EONR which, in turn, produced higher economic returns compared with other models. All models were equally stable with respect to input and output cost changes. The model used to predict EONR and economic estimates should be considered when evaluating published planning budgets supplied by economists to producers.
Waist Circumference, Body Mass Index, and Survival in Systolic Heart Failure: The Obesity Paradox Revisited

Abstract Background Higher body mass index (BMI) is associated with improved heart failure (HF) survival, but the role of waist circumference (WC) in HF outcomes has not been studied. Methods and Results A total of 344 patients with advanced systolic HF had WC and BMI measured at presentation. High WC was defined as ≥88 cm in women and ≥102 cm in men, and high BMI as ≥25 kg/m 2 . Two-year urgent heart transplant (UT)–free survival in high vs normal WC groups was 77.9% vs 64.3% ( P = .025) and in high vs normal BMI was 89.8% vs 58.2% ( P Conclusions High WC, an alternative anthropometric index of obesity more specific to abdominal adiposity, high BMI, and the combination of high WC/high BMI were each associated with improved outcomes in this advanced HF cohort, lending further support for an obesity paradox in HF. The role of body composition in HF survival should be a focus of future investigation.
Design of a novel small peptide targeted against a tumor-specific receptor.

EGFRvIII is the most common deletion variant of the epidermal growth factor receptor and is found in cancers of the brain, breast, ovary, and lung. The complete absence of the receptor in healthy tissues makes it an ideal tumor marker. We sought to design a peptide ligand against EGFRvIII for development as a diagnostic imaging agent. We used the concept of hydropathic complementarity to search for sequences whose amino acid sidechains display a reciprocal pattern of hydropathicity to those of the deletion junction of EGFRvIII. The resulting peptide (PEPHC1) was synthesized and tested for binding to EGFRvIII and EGFR. In in vitro assays, PEPHC1 bound the recombinant EGFRvIII extracellular domain or full-length EGFRvIII solubilized from cell membranes in preference to native EGFR. These results demonstrate the utility of hydropathic complementarity as a basis for the design of highly specific ligands that may prove useful as tumor-targeting agents.
Dose-ranging studies of clofilium, an antiarrhythmic quaternary ammonium.

Clofilium, a new quaternary ammonium antiarrhythmic without apparent ganglion-blocking effect, was evaluated in 25 patients, 22 with a history of ventricular arrhythmias and three with paroxysmal supraventricular arrhythmias. The study, including programmed atrial and ventricular stimulation, was carried out before and after infusion of 20 to 240 µg/kg IV as a single dose. Continuous Holter monitoring was carried out the day before the study through the fourth day after study, and laboratory parameters were monitored for up to 2 wk. There were no changes in intra-atrial and intraventricular conduction times or in AH or HV intervals. There were increases in QT interval, atrial effective refractory period, and ventricular refractory period. The atrioventricular nodal effective refractory period was unchanged. No side effects were noted, nor were changes in blood pressure or laboratory parameters. Monitoring revealed no change in frequency of premature ventricular complexes between the 24 hr before drug infusion and the 96 hr thereafter. In one patient refractoriness of the His-Purkinje system was increased and in two patients atrial fibrillation converted to sinus rhythm after clofilium. Three patients had sustained ventricular tachycardia with programmed stimulation before clofilium infusion; none had more than three repetitive ventricular responses after it. Clofilium increases atrial and ventricular effective refractory period without changing conduction time and, despite no apparent change in premature ventricular complex frequency, it can abolish the ability to induce ventricular tachycardia by programmed stimulation and is also well tolerated. Clinical Pharmacology and Therapeutics (1984) 35, 193–202; doi:10.1038/clpt.1984.26
Alliances and networks

This paper introduces a social network perspective to the study of strategic alliances. It extends prior research, which has primarily considered alliances as dyadic exchanges and paid less attention to the fact that key precursors, processes, and outcomes associated with alliances can be defined and shaped in important ways by the social networks within which most firms are embedded. It identifies five key issues for the study of alliances: (1) the formation of alliances, (2) the choice of governance structure, (3) the dynamic evolution of alliances, (4) the performance of alliances, and (5) the performance consequences for firms entering alliances. For each of these issues, this paper outlines some of the current research and debates at the firm and dyad level and then discusses some of the new and important insights that result from introducing a network perspective. It highlights current network research on alliances and suggests an agenda for future research. © 1998 John Wiley & Sons, Ltd.
Biphoton in a two-level cooled atomic ensemble

The temporal correlation of biphotons, generated from a two-level cooled atomic system, displays a photon anti-bunching effect, which corresponds to the interference between two types of nonlinear four-wave mixing processes occurring in such a medium.
Spray/jet cooling for heat flux high to 1kW/cm/sup 2/

High heat fluxes from relatively small surfaces as high as to 1kW/cm/sup 2/ are needed to be removed in the cooling of microelectronic chips. Spray cooling and jet cooling with high CHF and small wall temperature rise are attractive for use. To combine the advantages of spray and jet cooling together to reach the maximum cooling capacity, the present work designed new spray head including micro nozzle array and piezoelectric plate's vibration. The experimental results point out that this is a promising method using micro nozzle array and piezoelectric plate to break bulk liquid or streams into micro droplets. In this way the diameter of liquid droplets, velocity, and their locations can easily be controlled. Spray head A has a higher heat transfer coefficient with low wall superheat by forming a stable thin liquid film on the heated surface.
Suppression of natural killer cell-mediated bone marrow cell rejection by CD4+CD25+ regulatory T cells.

Naturally occurring CD4+CD25+ T regulatory (Treg) cells have been shown to inhibit adaptive responses by T cells. Natural killer (NK) cells represent an important component of innate immunity in both cancer and infectious disease states. We investigated whether CD4+CD25+ Treg cells could affect NK cell function in vivo by using allogeneic (full H2-disparate) bone marrow (BM) transplantation and the model of hybrid resistance, in which parental marrow grafts are rejected solely by the NK cells of irradiated (BALB/c × C57BL/6) F1 recipients. We demonstrate that the prior removal of host Treg cells, but not CD8+ T cells, significantly enhanced NK cell-mediated BM rejection in both models. The inhibitory role of Treg cells on NK cells was confirmed in vivo with adoptive transfer studies in which transferred CD4+CD25+ cells could abrogate NK cell-mediated hybrid resistance. Anti-TGF-β mAb treatment also increased NK cell-mediated BM graft rejection, suggesting that the NK cell suppression is exerted through TGF-β. Thus, CD4+CD25+ Treg cells can potently inhibit NK cell function in vivo, and their depletion may have therapeutic ramifications for NK cell function in BM transplantation and cancer therapy.
Sensitivity Analysis of the Nonparametric Nearest Neighbor Technique to Estimate Soil Water Retention

A k-nearest neighbor (k-NN) nonparametric algorithm variant was earlier applied successfully to estimate soil water retention. In this study, we tested the sensitivity of that k-NN variant to different data and algorithm options, such as: (i) estimations made to soils with differing distribution of properties; (ii) the use of different sample weighting methods; (iii) the number of ensembles we developed; (iv) data density in the reference data set; (v) the presence of outliers in the reference data set; (vi) unequal weighting of input attributes; and (vii) the addition of locally specific data to the reference data set. We used a hierarchical set of input attributes and data set sizes to develop ensembles of predictions using multiple randomized subset selections. The k-NN technique performed comparably well as neural network models developed on the same data. Using .50 ensemble members did not improve the results any further. The k-NN technique showed little sensitivity to the choice of sample weighting methods and to suboptimal weighting of input attributes. Differences in data density in parts of the reference data set did not substantially impact estimation errors. Estimations substantially improved for locally specific data when some local samples were included in the reference data set, while estimations for other samples remained almost unaffected. The k-NN technique showsa large degree of stability and insensitivity to different settings and options, can easily adopt new data without the need to redevelop equations, and is an effective alternative to other techniques to estimate soil water retention.
Pleiotropic Effects of the Duplicate Maize FLORICAULA/LEAFY Genes zfl1 and zfl2 on Traits Under Selection During Maize Domestication

Phenotypic variation on which selection can act during evolution may be caused by variation in activity level of developmental regulatory genes. In many cases, however, such genes affect multiple traits. This situation can lead to co-evolution of traits, or evolutionary constraint if some pleiotropic effects are detrimental. Here, we present an analysis of quantitative traits associated with gene copy number of two important maize regulatory genes, the duplicate FLORICAULA/LEAFY orthologs zfl1 and zfl2. We found statistically significant associations between several quantitative traits and copy number of both zfl genes in several maize genetic backgrounds. Despite overlap in traits associated with these duplicate genes, zfl1 showed stronger associations with flowering time, while zfl2 associated more strongly with branching and inflorescence structure traits, suggesting some divergence of function. Since zfl2 associates with quantitative variation for ear rank and also maps near a quantitative trait locus (QTL) on chromosome 2 controlling ear rank differences between maize and teosinte, we tested whether zfl2 might have been involved in the evolution of this trait using a QTL complementation test. The results suggest that zfl2 activity is important for the QTL effect, supporting zfl2 as a candidate gene for a role in morphological evolution of maize.
S-Adenosyl-l-methionine (SAMe): from the bench to the bedside—molecular basis of a pleiotrophic molecule

S-Adenosyl-L-methionine (SAMe), a metabolite present in all living cells, plays a central role in cellular biochemistry as a precursor to methylation, aminopropylation, and transsulfuration pathways. As such, SAMe has been studied extensively since its chemical structure was first described in 1952. Decades of research on the biochemical and molecular roles of SAMe in cellular metabolism have provided an extensive foundation for its use in clinical studies, including those on depression, dementia, vacuolar myelopathy, liver disease, and osteoarthritis. This article provides an overview of the biochemical, molecular, and therapeutic effects of this pleiotrophic molecule.
Development and validation of a large scale ICU simulation model with blocking

Intensive Care Units (ICUs) are specialized healthcare delivery units for patients that require the highest level of monitored care. ICUs are typically integrated into larger healthcare facilities and their operation is dependent on the operational status of other inpatient units and departments of the host facility. As patients transition between units, a lack of available beds in a requested unit may cause patients to stay in a level of care other than that which is clinically indicated, leading to unnecessary or unwarranted costs without improving medical outcomes. The simulation modeling work presented in this paper is part of a multidisciplinary research project aimed towards patient delays. We describe the design and validation of a large scale ICU simulation model that includes various inpatient units and departments of the hospital. We describe the (i) input data analysis, (ii) modeling of patient flow, and (iii) validation of the simulation model.