cssi/SciSciGPT-SciSciNet huggingface dataset:
Symbolic boundaries, subcultural capital and prescription drug misuse across youth cultures.

Prescription drug misuse among young adults has surged over the past decade. Yet the contexts surrounding this misuse remain unclear, particularly the subcultural contexts. Many young urban adults participate in youth cultures. This article describes the subcultural contexts of prescription drug misuse in youth subcultures. Drawing on ethnographic data collected over 12 months from different youth cultural scenes, the authors describe the subcultural bases of prescription drug misuse. The symbolic boundaries and subcultural capital inherent in these scenes shape the ways youth think about drugs and behave accordingly. While young adults are often lumped together by theorists, ethnographic data show considerable variation across these subcultures with regard to what may enable or inhibit prescription drug misuse. The broader subcultural ethos in each scene, as well as attitudes towards other types of drugs, frame the ways that prescription drugs are perceived and used in each of these settings. The findings highlight the role of symbolic boundaries and subcultural capital in shaping routine practices of drug use among young adults. These data show that education campaigns about prescription drug misuse should take into account the variability in youth cultural scenes to maximise the efficacy of these messages aimed at young adults.
Short characteristic integration of radiative transfer problems: formal solution in two-dimensional slabs.

Abstract A short characteristic method based on parabolic approximation of the source function is developed and applied to the solution of the two-dimensional radiative transfer problem on Cartesian meshes. The method is significantly faster for the evaluation of multidimensional radiation fields than those currently in use. Convergence as a functional of the grid resolution is discussed and linear and parabolic upwind interpolation are compared.
Telomerase and Telomere-Associated Proteins: Structural Insights into Mechanism and Evolution

Recent advances in our structural understanding of telomerase and telomere-associated proteins have contributed significantly to elucidating the molecular mechanisms of telomere maintenance. The structures of telomerase TERT domains have provided valuable insights into how experimentally identified conserved motifs contribute to the telomerase reverse transcriptase reaction. Additionally, structures of telomere-associated proteins in a variety of organisms have revealed that, across evolution, telomere-maintenance mechanisms employ common structural elements. For example, the single-stranded 3' overhang of telomeric DNA is specifically and tightly bound by an OB-fold in nearly all species, including ciliates (TEBP and Pot1a), fission yeast (SpPot1), budding yeast (Cdc13), and humans (hPOT1). Structures of the yeast Cdc13, Stn1, and Ten1 proteins demonstrated that telomere maintenance is regulated by a complex that bears significant similarity to the RPA heterotrimer. Similarly, proteins that specifically bind double-stranded telomeric DNA in divergent species use homeodomains to execute their functions (human TRF1 and TRF2 and budding yeast ScRap1). Likewise, the conserved protein Rap1, which is found in budding yeast, fission yeast, and humans, contains a structural motif that is known to be critical for protein-protein interaction. In addition to revealing the common underlying themes of telomere maintenance, structures have also elucidated the specific mechanisms by which many of these proteins function, including identifying a telomere-specific domain in Stn1 and how the human TRF proteins avoid heterodimerization. In this review, we summarize the high-resolution structures of telomerase and telomere-associated proteins and discuss the emergent common structural themes among these proteins. We also address how these high-resolution structures complement biochemical and cellular studies to enhance our understanding of telomere maintenance and function.
Statistical implications of pyrene and phenanthrene sorptive phenomena: effects of sorbent and solute properties.

A 3 × 2 factorial experiment in a generalized randomly complete block was conducted to assess the effects of soil type, soil preparation, and solute concentration on the sorptive behavior of pyrene (PYR) and phenanthrene (PHE). Three bulk soils were treated to remove the soil organic matter (SOM) or clay fractions, then spiked with an initial PYR/PHE concentration of either 3 or 15 mg/L. On average, 98.3% PYR and 91.3% PHE were sorbed to the bulk soils in 24 h, with 4.96 mg PYR kg−1 soil and 22.48 mg PHE kg−1 soil desorbed after three successive 24-h desorption steps. Both clay minerals and SOM greatly contributed to the sorptive behavior. For example, an average 95.1% and 96.1% of the initial PYR sorbed to the clay-removed and SOM-removed subsoils, respectively. Conversely, 16.5 mg/kg and 12.9 mg/kg of the sorbed PYR was desorbed from the clay-removed and SOM-removed subsoils, respectively.
Analysis and Measurement Of Self Mixing Of Transmitter Leakage in WCDMA Receivers

In this paper we analyze and measure the distortion due to self-mixing of transmitter (TX) leakage in WCDMA mobile receivers (RX). The self-mixing is primarily due to the second order non linearity of the mixer, which is very significant in WCDMA receivers due to the high power of the TX leakage signal. Existing published work has analyzed the dependence of this distortion, on the TX leakage power and second order non-linearity of the mixer. We go one step further and derive closed form expression for this distortion as a function of the power level of the TX, the second order nonlinearity of the mixer, and the number of equal power WCDMA channels in the TX leakage signal. This is also verified against measurements on a WCDMA receiver Chip
An introduction to the perplex number system

The perplex number system is a generalization of the abstract logical relationships among electrical particles. The inferential logic of the new number system is homologous to the inferential logic of the progression of the atomic numbers. An electrical progression is defined categorically as a sequence of objects with teridentities. Each identity infers corresponding values of an integer, units and a correspondence relation between each unit and its integer. Thus, in this logical system, each perplex numeral contains an exact internal representational structure; it carries an internal message. This structure is a labeled bipartite graph that is homologous to the internal electrical structure of a chemical atom. The formal logical operations are conjunctions and disjunctions. Combinations of conjunctions and disjunctions compose the spatiality of objects. Conjunctions may include the middle term of pairs of propositions with a common term, thereby creating new information. The perplex numerals are used as a universal source of diagrams. The perplex number system, as an abstract generalization of concrete objects and processes, constitutes a new exact notation for chemistry without invoking alchemical symbols. Practical applications of the number system to concrete objects (chemical elements, simple ions and molecules, and the perplex isomers, ethanol and dimethyl ether) are given. In conjunction with the real number system, the relationships between the perplex number system and scientific theories of concrete systems (thermodynamics, intra-molecular dynamics, molecular biology and individual medicine) are described.
Ras Effector Switching Promotes Divergent Cell Fates in C. elegans Vulval Patterning

The C. elegans vulva is patterned by epidermal growth factor (EGF) activation of Ras to control 1° fate, and 1° fate induces antagonistic Notch-dependent 2° fate. Furthermore, a spatial EGF gradient, in addition to inducing 1° fate, directly contributes to 2° fate via an unknown pathway. We find that in addition to its canonical effector, Raf, vulval Ras utilizes an exchange factor for the Ral small GTPase (RalGEF), such that Ras-RalGEF-Ral antagonizes Ras-Raf pro-1° fate activity. Consistent with its restricted expression pattern, Ral participates in EGF pro-2° activity. Thus, we have delineated a Ras effector-switching mechanism whereby position within the morphogen gradient dictates that Ras effector usage is switched to RalGEF from Raf to promote 2° instead of 1° fate. Our observations define the utility of Ras effector switching during normal development and may provide a possible mechanistic basis for cell and cancer-type differences in effector dependency and activation.
Propagation variability assessments of ship defense HEL and HPM performance in worldwide maritime boundary layer environments at wavelengths of 1.0642 μm, 2.141 μm, 3.16 mm and 12.2 cm

This study quantifies the variability in ship defense high energy laser (HEL) and high power microwave (HPM) performance due to atmospheric effects in the marine boundary layer relative to a commonly defined standard atmosphere. The atmosphere effects are defined using the worldwide probabilistic climatic database available in the High Energy Laser End-to-End Operational Simulation (HELEEOS) model. The expected propagation performance is assessed at 4 wavelengths (1.0642 μm, 2.141 μm, 3.16 mm, and 12.2 cm) across the world's oceans and mapped on a 1° × 1° grid. Scenarios evaluated are primarily near-surface and horizontal over ranges up to 9000 meters in which anticipated clear air aerosols and thin layers of fog, light rain, and various cloud types occur. Seasonal (summer and winter) and boundary layer variations for a range of relative humidity percentile conditions are considered to determine optimum employment techniques to exploit or defeat the environmental conditions. Optical turbulence impacts and numerous atmospheric particulate/hydrometeor distributions are evaluated based on their wavelength-dependent scattering and absorption effects on HEL/HPM engagement. HELEEOS includes a fast-calculating, first principles, worldwide surface to 100 km, atmospheric propagation and characterization package. This package enables the creation of profiles of temperature, pressure, water vapor content, optical turbulence, atmospheric particulates and hydrometeors as they relate to line-by-line layer transmission, path and background radiance at wavelengths from the ultraviolet to radio frequencies. Physics-based cloud and precipitation characterizations are coupled with physically correct temperature and moisture vertical lapse rates to create realistic atmospheric boundary layer effects. HELEEOS characterizes maritime aerosol environments using the Advanced Navy Aerosol Model (ANAM) or various representations of maritime particulates from the Global Aerosol Dataset (GADS). In the lowest 50 m, HELEEOS defines maritime optical turbulence with the Navy Surface Layer Optical Turbulence (NSLOT) model.
Invariant recognitive of cluttered scenes by a self-organizing ART architecture: CORT-X boundary segmentation

A neural network architecture is outlined that self-organizes invariant pattern recognition codes of noisy images. The processing stages are figure-ground separation, boundary segmentation, invariant filtering, and self-organization of a pattern recognition code by an ART 2 network. The article describes a new circuit for boundary segmentation, called the CORT-X filter, that detects, regularizes, and completes sharp (even one- pixel wide) image boundaries in up to 50% noise, while simultaneously suppressing the noise. The CORT-X filter achieves this competence by using nonlinear interactions between multiple spatial scales to resolve a design trade-off that exists between the properties of boundary localization, boundary completion, and noise suppression. The processing levels of the COR T-X filter are analogous to those of the Grossberg-Mingolla Boundary Contour System, but contain only feedforward operations that are easier to implement in hardware. The network nodes in these levels are analogous to cortical simple cells, complex cells, hypercomplex cells, and unoriented and oriented cooperative cells.
Nineteenth century roots of American world power relations: a study in historical political geography

Abstract This study is basically concerned with the spatial distribution of economic development and its relationship to the geopolitical processes as they emerge in the setting of the American landscape of the 19th century and their impact on 20th-century world power relations. The various historical processes are discussed as they relate to the rapid economic expansion and the westward movement of the frontier on the American continent and their influence on the geopolitical role America projects in today's world affairs. American ascendancy to national power, due in part to the closing of the frontier in the 1890s and increasing economic nationalism, resulted in expanding economic and later political penetration overseas and went hand in hand with naval exigency. The Spanish-American War at the end of the 19th century marked a turning-point in the world-wide geopolitical power position of the United States. The war left an important impact on domestic as well as on foreign policy and made the United States a world power to be reckoned with. It is the author's contention that 20th-century American foreign policy, especially those aspects sometimes referred to as a policy of containment against any one power wishing to achieve hegemony, either in the Americas, the European or the Pacific realms, ‘in a coalition hostile to her own interests’, has been concerned with these issues ever since independence was achieved. Its full implementation obviously had to wait until the United States had become a formidable economic, political and military power and thus could influence world-wide power decisions.
CULTURAL ISSUES IN COMPREHENSIVE SCHOOL REFORM

This article's primary interest is an exploration of the complexities of educational and social conditions encountered by African American males in public schools. It focuses on the ability and effectiveness of comprehensive school reform to overcome the barriers to learning that hinder the urban Black male student, such as concentrated poverty, drug use, and violence. Current trends in comprehensive school reform tend to overlook the importance of cultural relevancy and student/teacher cultural synchronization in educating Black males. As such, this article argues that efforts for the reform of policy and practice be conjoined with the recruitment of educators and school staff. Specifically, this article addresses the effectiveness of recruiting well-educated African American male teachers to teach in schools with large populations of African American male students.
DEVELOPMENT OF AN INLAND MARINE TRANSPORTATION RISK MANAGEMENT INFORMATION SYSTEM

Historically, inland marine transportation has been one of the most efficient and reliable modes of commercial freight transportation. However, hazardous material shipments have become more common on inland waterways, creating concerns about the dissemination of shipment information to land-based emergency responders immediately following an incident. Marine transportation accidents have demonstrated that a spill involving hazardous materials near a major urban area can have devastating consequences. For these reasons a prototypical decision support system for inland marine transportation risk management has been developed. The system is designed to support real-time response as well as planning decisions such as risk resource allocation and evaluation of potential response strategies. It can be applied to barge accidents as well as counterterrorism planning activities. The system is based on the integration of geographic information systems (GIS), database management systems, Global Positioning Systems, and the Internet. In the event of an incident, this system enables en route responders to view incident details via an Internet GIS map service. The map service contains data that describe land use, population, and dispersion results for air and surface water at downstream intakes. To illustrate system capability, a recent accident is re-created to show how the response could have been improved with system access. A case study showing planning applications is also provided.
Electrical effects of subgrain boundaries, twins, dislocations, and Te precipitation on long-wavelength IR HgCdTe photodiode arrays

HgCdTe crystals have a high density of intrinsic material defects generated either during the growth process itself or subsequent annealing steps. An understanding of the relationships between these material imperfections and the electrical performance of long-wavelength infrared (LWIR) HgCdTe photodiodes provides guidance in the choice of the growth technique and subsequent processing to minimize electrically detrimental defects. It also sets limits of material perfection required to achieve a specified performance level. Understandings of these relationships have been gained for subgrain boundaries, twins, dislocations, and Te precipitation in LWIR HgCdTe n-on-p photodiodes. Measurements of bias dependent dark current, responsivity, and noise as functions of defect density were performed on both arrays and test structures. This paper emphasizes the direct relationship between material defects and array performance. Wherever possible, the reader is referred to more detailed discussions. All the diodes reported in this study were planar, ion implanted structures using vacancy doped material. All reported measurements were taken at 77 K.
Fixed exchange rates: Credibility, flexibility and multiplicity

Abstract This paper surveys recent work on the sustainability of fixed exchange rates. It considers a dynamic version the Barro-Gordon framework, in which the level of a state variable (in this case debt) determines the pay-offs available to the government at each point in time. Multiple equilibria and self-fulfilling runs are possible, but only at certain levels of debt. A surprise devaluation can either increase or decrease future expected devaluation relative to a no-devaluation situation.
The tungsten-tungsten triple bond. XV. Synthesis, structure and reactivity of 1,2-W2[CH(SiMe3)2]2(NMe2)4: the remarkable inertness of a sterically-encumbered tungsten-amido complex

Abstract Addition of 1,2-W 2 Cl 2 (NMe 2 ) 4 (W≡W) to a toluene slurry of LiCH(SiMe 3 ) 2 (2 equiv) results in the formation of 1,2-W 2 [CH(SiMe 3 ) 2 ] 2 (NMe 2 ) 4 (W≡W) ( I ) in 79% isolated yield. Compound I has been characterized by 1 H and 13 C NMR, IR, elemental analysis and single-crystal X-ray diffraction. The molecule exists exclusively in the gauche conformation in solution and in the solid state with WW = 2.320(1) A. Compound I is very sterically encumbered as evidenced by: (1) large WWC angles, 110°, at the disyl ligand; (2) skewing of the NC 2 planes of the NMe 2 ligands off the WW vector; (3) anomalously large barriers to WNM 2 bond rotation in solution; (4) the inertness of I towards CO 2 and alcohols. However, compound I reacts with acetic anhydride to form 1,2-W 2 [CH(SiMe 3 ) 2 ] 2 (O 2 CMe) 4 (W≡W) ( II ) in 31% isolated yield. Compound II has been characterized by 1 H and 13 C NMR, IR, and elemental analysis. The mechanistic implications of these studies with regard to alcoholysis and CO 2 insertion reactions of other 1,2-W 2 R 2 (NMe 2 ) 4 compounds are discussed. Crystal data for 1,2-W 2 [CH(SiMe 3 ) 2 ] 2 (NMe 2 ) 4 at −140°C: space group P 2 1 / n , a = 12.555(3), b = 18.699(5), c = 15.214(4) A, β = 95.24(1)° and Z = 4.
Faster, more accurate, parallelized inversion for shape optimization in electroheat problems on a graphics processing unit (GPU) with the real-coded genetic algorithm

Purpose – Inverting electroheat problems involves synthesizing the electromagnetic arrangement of coils and geometries to realize a desired heat distribution. To this end two finite element problems need to be solved, first for the magnetic fields and the joule heat that the associated eddy currents generate and then, based on these heat sources, the second problem for heat distribution. This two-part problem needs to be iterated on to obtain the desired thermal distribution by optimization. Being a time consuming process, the purpose of this paper is to parallelize the process using the graphics processing unit (GPU) and the real-coded genetic algorithm, each for both speed and accuracy. Design/methodology/approach – This coupled problem represents a heavy computational load with long wait-times for results. The GPU has recently been demonstrated to enhance the efficiency and accuracy of the finite element computations and cut down solution times. It has also been used to speedup the naturally parallel g...
Cross-National Variations in Student Employment and Academic Performance: The Roles of National Context and International Law

Most existing research indicates that working students perform more poorly than do full-time students on standardized achievement tests. However, we know there are wide international variations in this gap. This article shows that national and international contexts help to explain the gap in the academic performance between working and nonworking middle-school students. We combined data from the 2003 Trends in International Mathematics and Science Study eighth-grade assessment with the country-specific information on socioeconomic and educational conditions, as well as the timing of each country’s ratification of an international treaty regulating child labor. Our multilevel analyses show that, while student employment is generally negatively associated with academic performance, this negative association is smaller in countries that by 1995 had ratified the International Labour Organisation’s Convention 138 on child labor. These findings highlight the role of national and international policy in structu...
Focused-electron-beam-induced processing (FEBIP) for emerging applications in carbon nanoelectronics

Focused-electron-beam-induced processing (FEBIP), a resist-free additive nanomanufacturing technique, is an actively researched method for “direct-write” processing of a wide range of structural and functional nanomaterials, with high degree of spatial and time-domain control. This article attempts to critically assess the FEBIP capabilities and unique value proposition in the context of processing of electronics materials, with a particular emphasis on emerging carbon (i.e., based on graphene and carbon nanotubes) devices and interconnect structures. One of the major hurdles in advancing the carbon-based electronic materials and device fabrication is a disjoint nature of various processing steps involved in making a functional device from the precursor graphene/CNT materials. Not only this multi-step sequence severely limits the throughput and increases the cost, but also dramatically reduces the processing reproducibility and negatively impacts the quality because of possible between-the-step contamination, especially for impurity-susceptible materials such as graphene. The FEBIP provides a unique opportunity to address many challenges of carbon nanoelectronics, especially when it is employed as part of an integrated processing environment based on multiple “beams” of energetic particles, including electrons, photons, and molecules. This avenue is promising from the applications’ prospective, as such a multi-functional (electron/photon/molecule beam) enables one to define shapes (patterning), form structures (deposition/etching), and modify (cleaning/doping/annealing) properties with locally resolved control on nanoscale using the same tool without ever changing the processing environment. It thus will have a direct positive impact on enhancing functionality, improving quality and reducing fabrication costs for electronic devices, based on both conventional CMOS and emerging carbon (CNT/graphene) materials.
Energy and economic evaluation for corn and grain sorghum processing for cattle

Abstract Five grain processing alternatives were compared for corn and grain sorghum in feedlots of 5000 and 20,000 head capacity. Cattle growth responses for each processed grain were obtained from the published literature and 1980 energy and economic grain processing budgets were obtained from feedlots and commercial mill construction firms. Net value per t of processed grain dry matter ranged from $7.71 to a negative $9.35 for 5000 head feedlots, and from $9.33 to a negative $8.50 for 20,000 head feedlots. Processing energy cost per t of grain dry matter for a 20,000 head feedlot was $0.08, 2.96, 0.20, 0.11 and 0.33, respectively, for dry processed, steam flaked, reconstituted, early harvest-ground-ensiled and early harvest-acid treated grains. Comparable values for a 5000 head feedlot were $0.08, 4.25, 0.23, 0.13 and 0.46 per t. Reconstitution appeared to represent the most favorable processing alternative for either grain or size of feedlot combination. Energy balance data indicated that for each MJ of energy applied to processing, 3.5, 32.6, 23.3 or 2.1 MJ of empty body energy were recovered in cattle fed reconstituted, early harvest-ground-ensiled, steam flaked or early harvest-acid treated corn, respectively. Energy balance was more favorable for grain sorghum that corn. Interest cost on grain in storage greatly detracted from the economic value of the early harvested systems and would need to be offset by alternative purchasing systems and/or purchase of grain at harvest when prices are usually lower.
Multi-sensor networked estimation in electric power grids

The performance of a continuous-discrete Kalman filter using multi-sensor observations with irregular sampling patterns is analyzed in terms of the dynamics of the associated (predicted) error-covariance matrix. Irregular sampling may occur as a result of differences in sampling rates and/or lack of synchrony in a geographically-distributed power system. Alternatively, it may also be caused by intermittency (i.e., packet-loss) in the communication link between a sensor and an estimation/control center. We show that the ensemble-and time-averaged error covariance depends only on system parameters and on the characteristic function of the irregular sampling interval of the multi-sensor sampling pattern. We obtain lower and upper bounds on the average error covariance, as well as a necessary condition for its stability, expressed in terms of the region of convergence of the sampling interval characteristic function.
Statistical analysis of affect of parameter variations on double-negative behavior of metamaterials

Non-metallic double-negative (DNG) metamaterials can be formed by three-dimensional (3D) periodic arrays of non-metallic spheres. Since such metamaterials usually show DNG behavior in the neighborhood of the Mie resonances of the spheres, even small variations in their geometric and electromagnetic material parameters affect their DNG behavior significantly. Practically, all fabrications induce these variations in the form of tolerances. This paper presents a statistics-based analysis of the affect of fabrication tolerances on the effective constitutive parameters and DNG bandwidths of non-metallic metamaterials. Results show that even 3% variation in the geometric and electromagnetic material parameters may extinguish the DNG behavior of a non-metallic metamaterial.
Adaptive voltage tracking control of zeta buck-boost converters

Compensators and PI controllers have been designed and used for control of Zeta converters. However, frequent voltage variations in some applications such as maximum power point tracking of solar power require a high profile voltage tracking control. In addition, load resistance and inductor current influence the performance of conventional controllers. This paper illustrates the design and application of a model reference adaptive controller for output voltage tracking of a zeta converter. The results, compared with a PI controller, demonstrate a close tracking profile with minimal control effort and elimination of the load resistance dependencies.
The structure of Selmer groups

Our objective in this paper is to prove a rather broad generalization of some classical theorems in Iwasawa theory.
Victim and offender accounts of interpersonal conflict: autobiographical narratives of forgiveness and unforgiveness.

Participants wrote 2 narratives that described an incident in which they angered or hurt someone (offender) or in which someone angered or hurt them (victim) and the offense was forgiven or not forgiven. Victims portrayed the offense as continuing (open), and offenders portrayed the offense as over (closed). Forgiveness narratives portrayed offenses as closed and with positive outcomes; however, for some victims, forgiveness coincided with continued anger, suggesting incomplete forgiveness. Dispositional empathy was associated with more benign interpretations of offenses, and situational empathy (e.g., for the offender) was associated with victims' forgiveness. In contrast, offenders' empathy for victims was associated with less self-forgiveness. Thus, both victim or offender role and forgiveness must be considered to understand narratives of interpersonal offenses.
Crush Analyses of Multi-Level Equipment

Non-linear large deformation crush analyses were conducted on a multi-level cab car typical of those in operation by the Southern California Regional Rail Authority (SCRRA) in California. The motivation for these analyses was a collision, which occurred in Placentia, CA, on April 23, 2002. The final deformed state of the leading cab car was unusual. This behavior contrasted with previous testing and analysis experience of single level equipment in collisions. This investigation explores the structural response of multi-level car structures. The structure of the multi-level equipment differs from single level equipment in that a significant change occurs in the load path from where load enters through the coupler and is subsequently reacted aft of the body bolster of the car. This change in load path results from a change in geometry of the car to accommodate quarter point doors and the upper level of the car. Load enters at the typical coupler height but descends to the lower platform level of the car through a transition structure. To better understand the influence of the varied geometry, a series of calculations were performed to obtain the force-crush characteristics and modes of deformation for the cab car subjected to a series of different initial conditions. Crush models were developed of both the lead and trailing end of the car, as well as the center section of the car. In addition to these sub-models, a full car model was constructed. Results from the sub-model analyses indicate that the longitudinal strength of the trailing end is comparable to that of the lead end, and the center section of the car is significantly stronger than either end. This suggests that crush will most likely occur at the ends of the car when it is overloaded. Initial conditions similar to the Placentia, CA accident were also investigated to better understand the atypical mode of deformation that occurred. These results indicated that the multi-level equipment can resist high force levels for longer crush distances than single level platform vehicles but will eventually experience softening behavior, which will result in focused crush at one end of a car.
Membrane insertion and lateral mobility of synthetic amphiphilic signal peptides in lipid model membranes

Amphiphilic signal sequences with the potential to form alpha-helices with a polar, charged face and an apolar face are common in proteins which are imported into mitochondria, in the PTS permeases of bacteria, and in bacterial rhodopsins. Synthetic peptides of such sequences partition into the surface region of lipid membranes where they can adopt different secondary structures. A finely controlled balance of electrostatic and hydrophobic interactions determines the 'affinity' of amphiphilic signal peptides for lipid membranes, as well as the structure, orientation and depth of penetration of these peptides in lipid bilayer membranes. The ability of an individual peptide to associate with lipid bilayer membranes in several different modes is, most likely, a general feature of amphiphilic signal peptides and is reflected in several common physical properties of their amino acid sequences.
Private Insurance, Selection, and Health Care Use

Observed differences in medical utilization between the privately insured and uninsured reflect the combined effects of self-selection and insurance incentives (moral hazard). This article provides a Bayesian framework for decomposing the disparity into incentive and selection components. The effect of self-selection in private insurance on the number of doctor visits is estimated using a multiyear sample of the U.S. adult non-Medicare population obtained from the Medical Expenditure Panel Survey. We use a flexible econometric framework based on the “Roy model” and develop a Markov chain Monte Carlo algorithm. We estimate the distribution of treatment effects and find strong evidence indicating selection, which accounts, on average, for 50% or more of the observed disparity in doctor visits.
Long-term influences of livestock management and a non-native grass on grass dynamics in the Desert Grassland

Abstract Density of 23 perennial grass species was measured in 25 permanent plots nine times between 1972–2000. Grass density was not related to the intensity of livestock grazing. Only one species expressed a difference between the summer rest and no summer rest with heavier stocking grazing treatments: bush muhly (Muhlenbergia porteri Scribn. ex Beal) density was less under the no summer rest with heavier stocking treatment. Beginning in 1975, the non-native Lehmann lovegrass (Eragrostis lehmanniana Nees) spread from distant seedings to one plot, and by 1991, it was the dominant species on most plots. The density of native species was not related to the length of time that the non-native lovegrass was present on a plot. In general, native species declined prior to the arrival and increase of the non-native lovegrass.
Occipitocervical fusion with a five-millimeter malleable rod and segmental fixation

Although occipitocervical fusion is frequently used for instability of the upper cervical spine and the occipitocervical articulation, most currently used techniques have one or more of the following disadvantages: the necessity for sublaminar wires, the use of occipital screws, a fixed angle of instrumentation, or the necessity for routine postoperative halo immobilization. Moreover, many reported techniques are associated with a high rate of nonunion or instrumentation failure. We present our experience with a technically simple method of obtaining rigid occipitocervical arthrodesis using a 5-mm malleable rod that is fixed to the skull by a pair of wires passed through four suboccipital burr holes. Segmental spinal fixation is achieved with Wisconsin interspinous wires and is occasionally supplemented with sublaminar wires. Supplemental autogenous bone graft is used in all cases. A cervical collar is routinely used for postoperative immobilization. The results of treatment were retrospectively reviewed in 16 patients with an average age of 49.4 years (range, 9-69). Mean follow-up was 24 months (range, 12-36 mo). The indication for fusion was instability of the occiput-C1-C2 complex as a result of Chiari malformation, rheumatoid disease, skull base tumor resection, basilar invagination, ankylosing spondylitis, Down's syndrome, cervical laminectomy, and trauma. The average number of levels fused was 5.4 (range, O-C3 to O-T3). Successful occipitocervical arthrodesis was achieved in all but one of the surviving patients. The single patient with a pseudarthrosis was successfully managed with supplemental bone grafting and halo immobilization. There were two deaths from medical complications in chronically ill patients. Other complications included one postoperative instrumentation loosening, one myocardial infarction, and one superficial occipital decubitus. In conclusion, rodding and segmental interspinous wiring is an effective, technically simple method of obtaining rigid occipitocervical fixation, which obviates the need for bulky orthoses.
Simultaneous concentration and separation of coumarins using a molecular micelle in micellar affinity gradient focusing.

We report the use of a molecular micelle for the simultaneous separation and concentration of neutral and hydrophobic analytes using micellar affinity gradient focusing (MAGF). The technique, MAGF, combines the favorable features of micellar electrokinetic chromatography and temperature gradient focusing. The focusing of neutral coumarin analytes was accomplished by the use the molecular micelle, poly(sodium undecenyl sulfate) (poly-SUS). Concentration enhancements of 10−25-fold/min were achieved for focusing of the coumarin dyes. The effect of varying the temperature gradient on the resolution of two of the coumarin dyes was also investigated, demonstrating that improved resolution could be achieved by reducing the steepness of the temperature gradient. In addition, with scanning-mode MAGF (in which the peaks are sequentially scanned past a fixed detection point by varying the buffer counterflow velocity), the use of poly-SUS was shown to produce repeatable and quantitative analyte peaks, making quantita...
Developing Research Agendas on Whole School Improvement Models: The Model Providers' Perspective.

The current education policy environment places a heavy emphasis on scientifically based research. This article examines how whole school improvement models approach the development of a research agenda, including what influences and challenges model providers face in implementing their agenda. Responses also detail the advantages and disadvantages model providers see in using internal and external research teams to carry out their research agenda. In addition, the article addresses common themes about how model providers believe their research agenda interacts with the public realm, including how education consumers use research in selecting a whole school improvement model and how their models are portrayed in systematic reviews of their models' research.
Stimulation of endothelial secretion of tissue-type plasminogen activator by repetitive stretch.

Abstract Endothelial cells (EC) synthesize many of the fibrinolytic components and anticoagulants present in plasma. EC have been demonstrated to release tissue type plasminogen activator (t-PA) and its rapid inhibitor type 1 plasminogen activator inhibitor (PAI-1). In vivo, EC lining a blood vessel are exposed to the forces of the circulation, predominantly shear stress and pulsatile stretch. We have previously reported that repetitive stretch of EC in culture will stimulate prostacyclin secretion. In this study, the effects of cyclic stretch on the production of t-PA and PAI-1 by cultured EC were examined. EC harvested from human saphenous vein were seeded in culture plates with flexible membrane bottoms and grown to confluence. Vacuum (−20 kPa) was used to deform the membrane bottoms to 24% maximum strain. EC in the experimental group were subjected to 24% maximum strain at 60 cycles/min (0.5 sec elongation alternating with 0.5 sec relaxation), while control EC were grown on the same membranes but kept stationary in the same incubator. After 1, 3, and 5 days, the cell numbers were counted and the media were collected and analyzed for t-PA and PAI-1 by ELISA. The result shows a significant increase in t-PA production with the cyclic stretch on Days 3 and 5. There was no significant difference in PAI-1 levels in stretched versus stationary EC. We concluded that cyclic stretch of EC in vitro can selectively stimulate t-PA production and may account for the relative nonthrombogenicity of the endothelium in vivo.
Women and War in Latin America, 1950–2000

War is broadly and historically considered to be the most masculine of domains, and histories of war tend to reflect this conception. As the historian's lens adjusts to focus on women and war, it expands the scope through which to study war and we engage more closely with categories of people not traditionally viewed as central to war stories: mothers of soldiers, prostitutes, rape victims. Scholarship on war, even when it includes women, tends to focus upon the great powers. With further adjustments to the historical lens, Latin American wars also come into view. Women have long participated in struggles for liberation and other wars in Latin America, yet scholarship on this history is still fairly new and emergent. This article provides a synthesis of scholarship on women and war in Latin America from 1950 to 2000. Such a synthesis entails going beyond the more familiar accounts of women as maternal peacemakers or combatants to include women's support for military dictatorships, prostitutes’ work as rebel spies, and maternal anti-draft activists. As we incorporate a broader array of women's roles in war, we stand to gain new insights into the history of war itself – how war has been conducted, the mundane but absolutely essential tasks required to keep a military functioning, and the popular support necessary to fill the ranks.
Session lengths and IP address usage of smartphones in a university campus WiFi network: Characterization and analytical models

Smart mobile handheld devices (MHDs) are being adopted at a fast speed. Compared to wireless non-handheld devices (NHDs), MHDs tend to be more mobile and can be used more opportunistically. In this paper, we study two important network usage characteristics of MHDs, namely session lengths and IP address usage, in a university campus WiFi network. Specifically, we analyze two five-week long DHCP traces collected from the network, characterize session lengths of MHDs, and develop two hyper-exponential models to capture the distribution of session lengths.We further characterize the IP address usage of MHDs, and develop two analytical models to predict the number of concurrent IP addresses that are being used by MHDs at one point of time. Goodness of fit tests indicate that our analytical models of session lengths provide good fit, and evaluation results demonstrate that the predictions from our models for IP address usage are accurate. Our results provide important insights on managing MHDs as they are being adopted rapidly in WiFi networks.
Modified bond moment theory for the spectroscopic determination of the CH bond moment

Abstract The CH bond moment, μCH, and its derivatives are calculated by a modified bond moment theory for the cases of methane and crystalline n-paraffins. In addition to the bond-stretching derivative, ∂μ CH ∂R the bond-bending derivatives ∂μ CH ∂x n and ∂μ CH ∂y n are also considered, where x n and y n are atomic displacements normal to the bond, and n labels the atoms of the molecule such that n = 1, 2 labels the end atoms of a bond, and n > 2 labels the nearest neighbors. Using experimental data from solid n-paraffins with 21 to 36 carbon atoms it is found that, in the CH2-group, μ CH ⋍ 0.01 debye and that the bond bending derivatives are about ten times larger than μCH and comparable in magnitude to ∂μ CH ∂R . Intensity formulas for methane are developed and its is tentatively suggested that μCH in methane is considerably smaller than the accepted value of 0.3 debye. This hypothesis could be checked if the infrared intensities of CD4 were known.
Adaptive Representations for Pattern Recognition

An adaptive method of generating a set of correlation patterns for measuring the characteristics of unknown patterns is discussed. The correlation patterns change with time to follow slow changes in the configuration of the inputs so that they remain optimum for the most recent inputs. The relationship between the changing set of measurement patterns and the actual identification process is discussed. Results of experiments with a simulated system are presented.
An evaluation of the abuse potential of modafinil using methylphenidate as a reference

Modafinil is a unique wake-promoting agent. Preclinical studies indicate a mechanism of action which is distinct from that of amphetamine or methylphenidate. To compare the pharmacodynamic profiles of modafinil, methylphenidate, and placebo in humans, a double-blind Latin square crossover study was conducted in 24 male volunteers with a history of polysubstance abuse that included the stimulant cocaine. Each subject was given single oral doses of methylphenidate (45 mg or 90 mg), modafinil (200 mg, 400 mg or 800 mg) and placebo. Measures of subjective, behavioural, and physiological responses were evaluated at fixed intervals during 72 h after each dosing occasion. Subjects discriminated both modafinil and methylphenidate from placebo. Subjects liked the effects of both drugs. However, modafinil differed from methylphenidate in its lack of a significant response on the Amphetamine Scale of the Addiction Research Center Inventory. The profile of physiological effects for modafinil differed from methylphenidate in that it showed greater inhibition of observed and reported sleep, less facilitation of orthostatic tachycardia and less reduction of caloric intake. These findings are consistent with preclinical pharmacological data suggesting that modafinil is not an amphetamine-like agent.
Big science victim of budget game

In an apparent effort to make certain that the newly proposed cuts in the federal budget reach all factions, except of course those that involve the military-industrial complex, David Stockman, the key player of the ‘budget game,’ has leaked to the press some of his plans that could virtually eliminate many parts of big science over the next decade. Two agencies that are important in this respect, and important to a large proportion of the geophysical community, are NASA and NOAA. There are portions of the budgets of both of these agencies that because of military significance will go unscathed. Unfortunately the ‘across-the-board’ cuts proposed by OMB Director Stockman will have to be concentrated on the rest that are relatively indefensible from a military standpoint and that turn out to be the most science intensive.
Comparison of Forward Selection, Backward Elimination, and Generalized Simulated Annealing for Variable Selection

Abstract In order to obtain quantitative information, it is often necessary for a chemist to employ regression methods. An algorithm is described for determining the optimal subset of variables which gives the best prediction in regression analysis. The procedure is based on the generalized simulated annealing method (GSA) of optimization. From a comparison study with standard methods of variable subset selection by forward selection and backward elimination, GSA is found to perform better. Three data sets are used for distinction purposes. Two of the data sets are relatively small, allowing comparison to the global variable subset obtained by computing all possible variable combinations.