cssi/SciSciGPT-SciSciNet huggingface dataset:
Promotion of Family Recreation for a Nature-Based Destination

The promotion of intergenerational family recreation in a nature-based tourism destination could be an effective vehicle in the provision of a healthy youth development. Nature-based recreation participation in particular often offers opportunities for a family to grow together and maintain its cohesiveness. The purpose of this study is to explore the factors associated with the motivation to visit a nature-based destination for family recreation. A total of 1282 surveys were administrated and data were analyzed. The results of the study indicated that there is a relationship between the characteristics of visitation and the motivation for family recreation in a natural tourism destination. Travel distance, education background, marital status, visiting status, and group type are significant predictors of the motivation for family recreation. Further, the study revealed that travelers with children reported less satisfaction of their visitation than those without children. Research limitations and implica...
Meßgeräte und Meßsysteme

Die Mestechnik bietet heute fur akustische Messungen eine grose Auswahl empfindlicher Mikrofone, Beschleunigungsaufnehmer, Mesgerate und Signalanaly-satoren, die eine genaue Analyse der Schallfelder sowohl im Innenraum des Fahrzeugs als auch in seiner Umgebung ermoglichen. Dabei hat sich in den letzten Jahren — wie uberall in der Mestechnik — eine Verschiebung zu digitalen Mesgeraten und rechnergestutzten Methoden ergeben.
Questions on the Vitamin E Study

In Reply.— Regarding the efficacy of a few early intramuscular injections of vitamin E to decrease the incidence and severity of intraventricular hemorrhage reported by Speer et al,1 Jansen adds his concerns to those already expressed in the commentary by Phelps.2 The intraventricular hemorrhage data were a retrospective study, the inborn and outborn infants were not randomly separated into control and treatment groups, and the small numbers resulted in some nonsignificant differences between control infants and treated infants.
Partnership Allocation of Selected Real Estate Tax Credits

There is surprisingly little material available that speaks to the proper allocation of tax credits within a partnership. This paper seeks to fill that gap, discussing both the general rule applicable to the allocation of tax credits as well as the special rule applicable to the allocation of investment tax credits including the rehabilitation tax credit. In addition, the application of tax credit recapture is considered including partnership transactions that can trigger credit recapture.
Jimmy’s Baby Doll and Jenny’s Truck: Young Children’s Reasoning About Gender Norms

To assess the flexibility of reasoning about gender, children ages 4, 6, and 8 years (N = 72) were interviewed about gender norms when different domains were highlighted. The majority of participants at all ages judged a reversal of gender norms in a different cultural context to be acceptable. They also judged gender norms as a matter of personal choice and they negatively evaluated a rule enforcing gender norms in schools. Older children were more likely to show flexibility than younger children. Justifications obtained from 6- and 8-year-olds showed that they considered adherence to gender norms a matter of personal choice and they viewed the rule enforcing gender norms as unfair.
Cardiorespiratory Fitness May Help in Protecting Against Depression Among Middle School Adolescents

PURPOSE: Cross-sectional studies demonstrate a robust association between depression, physical activity, and cardiorespiratory fitness in adolescents, but longitudinal evidence that can better parse the direction of these effects is scarce and conflicting, and no such studies in adolescents have considered the importance of fitness (as opposed to physical activity per se) for preventing depression. Therefore, the present study sought to determine if cardiorespiratory fitness in the first year of middle school (sixth grade) would protect against developing depression a year later (seventh grade), even after controlling for other risk factors (i.e., preexisting depression levels and weight status). METHODS: Participants (N = 437 with 54.9% female) were recruited from six different middle schools during their sixth-grade year and reassessed during the seventh grade. At each assessment, participants completed self-report measures of depression and fitness. Participants were also weighed and were asked to complete a shuttle-run at both points. RESULTS: A cross-lagged panel model indicated that cardiorespiratory fitness in the sixth grade was associated with significantly less depression by the seventh grade in girls, even after controlling for preexisting depression and weight. The effect was in the same direction for boys, but was nonsignificant. In both cases, effects were modest to small. CONCLUSIONS: Cardiorespiratory fitness had a small, but significant protective effect against developing depression in middle school girls, and may have a similar but smaller effect in boys. Promotion of cardiorespiratory fitness can be an important strategy for preventing depression in middle school adolescents, but needs to be coupled with interventions that more directly address symptom treatment. Language: en
An overview of industrial software documentation practice

A system documentation process maturity model and assessment procedure were developed and used to assess 91 projects at 41 different companies over a seven year period. During this time the original version evolved into a total of four versions based on feedback from industry and the experience gained from the assessments. This paper reports the overall results obtained from the assessments which strongly suggest that the practice of documentation is not getting a passing grade in the software industry. The results show a clear maturity gap between documentation practices concerned with defining policy and practices concerned with adherence to those policies. The results further illustrate the need to recognize the importance of improving the documentation process, and to transform the good intentions into explicit policies and actions.
Neural network solution for finite-horizon H ∞ state feedback control of nonlinear systems

In this article, neural networks are used to approximately solve the finite-horizon optimal H∞ state feedback control problem. The method is based on solving a related Hamilton Jacobi Isaacs equation of the corresponding finite-horizon zero-sum game. The neural network approximates the corresponding game value function on a certain domain of the state-space and results in a control computed as the output of a neural network. It is shown that the neural network approximation converges uniformly to the game-value function and the resulting controller provides closed-loop stability and bounded L2 gain. The result is a nearly exact H∞ feedback controller with time-varying coefficients that is solved a priori offline. The results of this article are applied to the rotational/translational actuator benchmark nonlinear control problem.
An integrated synchronization and consistency protocol for the implementation of a high-level parallel programming language

This paper presents experimental results that characterize the performance of the integrated synchronization and consistency protocol used in the implementation of Jade, an implicitly parallel language for coarse-grain parallel computation. The consistency protocol tags each replica of shared data with a version number. The synchronization algorithm computes the correct version numbers of the replicas of shared data that the computation will access. Because the protocol piggybacks the version number information on the synchronization messages, it generates fewer messages than standard update and invalidate protocols. This paper characterizes the performance impact of the consistency protocol by presenting experimental results for several Jade applications running on the iPSC/860 under several different Jade implementations.
A numerical method for finding multiple co-existing solutions to nonlinear cooperative systems

In this paper, a local min-orthogonal method is developed to solve cooperative nonlinear elliptic systems for multiple co-existing solutions. A characterization of co-existing critical points of a dual functional is established and used as a mathematical justification for the method. The method is then implemented to numerically solve two coupled nonlinear Schrodinger equations which model spatial vector solitons propagating in a saturable bulk nonlinear medium for multiple co-existing solutions.
The effects of temperature on bighorn population estimates in Yellowstone National Park

The effects of temperature on bighorn population estimates for Yellowstone National Park's Mt. Evert's winter range were examined. Based on work by Houston (1982), a bipartite relationship was hypothesized, whereby the effects of temperature upon the observability of sheep was predicted to be significantly different in those portions of the temperature spectrum where snowmelt occurs. Analyses of the regressions of bighorn numbers observed on mean daily ground temperature supported this hypothesis. At temperatures less than 0°C, counts increased significantly with temperature at a rate of 3.15∶1, but were found to underestimate bighorn numbers and be unreliable as estimators of population trend. Counts conducted at 0° to 7°C increased with temperature at a significantly greater rate of 18.53∶1. However, correction for population increases suggested this relationship reflected the intercorrelation of temperature and year; a result of selecting increasingly better census conditions over time. It was concluded that no additional benefit accrued from further increases in temperature once snowmelt occurred and that counts conducted at 0° to 7°C (the period between snowmelt and spring migration) were equally reliable. The importance of regarding snowmelt as a threshold value was underscored by the vastly different conclusions regarding bighorn population trends which have been drawn by different researchers from very nearly the same data. While previous research concluded that apparent population increases were the result of temperature-biased data, this study concluded that the apparently sigmoidal population growth was real.
Systematic Embryology of the Araceae

Embryological data of systematic significance to the family Araceae are reviewed and analyzed, with special attention given to the determination of character-state polarities. Character-states considered primitive within the family include: presence of endothecial thickenings; binucleate, starchless pollen; anatropous, crassinucellate ovules with a thick nucellar cap and a single, unbranched funicular bundle; solanad or caryophyllad embryogeny; helobial endosperm development, with 2–8 cells in the chalazal chamber andab initio cellular division in the micropylar chamber; and endosperm present in ripe seeds. The phylogenetic implications of these conclusions are discussed, and promising avenues for future research are indicated.
Evaluation of MOST functions and roughness length parameterization on sensible heat flux measured by large aperture scintillometer over a corn field

Abstract As part of a comprehensive study investigating how subsurface drainage systems affect the energy and water balances on land surfaces, a large aperture scintillometer (LAS) was used to determine the sensible heat and momentum fluxes over a corn (Zea mays) field. To keep the flux footprint of the observation within the 22 ha field boundary, the LAS had to be placed at a height no greater than 1.8 m above displacement height. As a result, the surface layer was mostly near-neutral at the LAS path height. Sensible heat fluxes were derived from the LAS measurements (HLAS) using four different Monin–Obukhov Similarity Theory (MOST) functions for temperature (fT). While correlating well with the sensible heat fluxes measured by the Eddy covariance system (HEC), the values of HLAS were systematically higher if the rule of thumb formula for estimating the roughness length (z0) was used. The use of this rule of thumb formula led to higher estimates than the EC measurements of the frictional velocity u*, to which HLAS is particularly sensitive under near-neutral conditions. With a modified formula for z0, a better agreement between HLAS and HEC is achieved for all the fT functions tested. Using the fT function (W71) proposed by Wyngaard et al. (1971) and the improved estimate of z0, HLAS agreed with HEC within 32 W m−2 and with a regression slope of 1.0 ± 0.05.
Use of airborne imaging spectrometer data to map minerals associated with hydrothermally altered rocks in the northern grapevine mountains, Nevada, and California

Abstract Three flightlines of Airborne Imaging Spectrometer (AIS) data, acquired over the northern Grapevine Mountains, Nevada, and California, were used to map minerals associated with hydrothermally altered rocks. The data were processed to remove vertical striping, normalized using an equal area normalization, and reduced to reflectance relative to an average spectrum derived from the data. An algorithm was developed to automatically calculate the absorption band parameters band position, band depth, and band width for the strongest absorption feature in each pixel. These parameters were mapped into an intensity, hue, saturation (IHS) color system to produce a single color image that summarized the absorption band information, This image was used to map areas of potential alteration based upon the predicted relationships between the color image and mineral absorption band. Individual AIS spectra for these areas were then examined to identify specific minerals. Two types of alteration were mapped with the AIS data. Areas of quartz-sericite-pyrite alteration were identified based upon a strong absorption feature near 2.21 μm, a weak shoulder near 2.25 μm, and a weak absorption band near 2.35 μm caused by sericite (fine-grained muscovite). Areas of argillic alteration were defined based on the presence of montmorillonite, identified by a weak to moderate absorption feature near 2.21 μm and the absence of the 2.35 μm band. Montmorillonite could not be identified in mineral mixtures. Calcite and dolomite were identified based on sharp absorption features near 2.34 and 2.32 μm, respectively. Areas of alteration identified using the AIS data corresponded well with areas mapped using field mapping, field reflectance spectra, and laboratory spectral measurements.
Restricting fourth-order gravity via cosmology

The cosmology of general fourth-order corrections to Einstein gravity is considered, both for a homogeneous and isotropic background and for general tensor perturbations. It is explicitly shown how the standard cosmological history can be (approximately) reproduced and under what condition the evolution of the tensor modes remain (approximately) unchanged. Requiring that the deviations from general relativity are small during inflation sharpens the current constraints on such corrections terms by some thirty orders of magnitude. Taking a more conservative approach and requiring only that cosmology be approximately that of general relativity during big bang nucleosynthesis, the constraints are improved by 4--6 orders of magnitude.
Antidepressants and testicular cancer

Purpose Re-examine association of fluoxetine and paroxetine with risk of testicular cancer noted in drug screening, with 4 years more follow-up and expanded study of these and other antidepressant drugs.
Development of a Contingency Model Organizational Assessment Survey for Management Consultants

The development of an Organizational Assessment Package (OAP) for use by Air Force management consultants is presented. Development was based on a contingency model of effectiveness with separate inventories measuring the major components of the model. Data were collected using the OAP from 4,786 Air Force military and civilian personnel. Factor analyses resulted in 22 factors which were orthogonal within each inventory. Internal consistency indices were computed using the coefficient alpha formula for the highest loading items which defined each factor. Some redundancy between inventories was identified and recommendations for items and factors for an operational OAP were made.
Calcite-dolomite-magnesite stability relations in solutions: the effect of ionic strength

Abstract The effect of total solution concentration on the Ca: Mg ratio at the magnesitedolomite and the dolomite-calcite boundaries in CaCl2MgCl2CO2 solutions has been determined between 280 and 420°C. Below about 410° a decrease in the total concentration of the solutions produces a displacement of both boundaries toward lower values of the Ca:Mg ratio. Observed displacements are small but increase with decreasing temperature.
Flow in a two-dimensional channel with a rectangular cavity

Flow structure in rectangular cavity in lower wall of two dimensional channel for various aspect ratios and Reynolds numbers
Specifications For Diamond-Turned Surfaces

The surfaces of diamond machined optics are described in terms of the spatial frequency of the errors. Certain of these errors which are unique to diamond machined optics, such as, the highly correlated errors due to tool advance and the error due to machine centering uncertainty, are discussed in detail. The imaging effects of the errors are derived. A framework for specifying diamond machined optics, based on the imaging effects is presented.© (1979) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Piloted Evaluation of Damage Accommodating Flight Control Using a Remotely Piloted Vehicle

Toward the goal of reducing the fatal accident rate of large transport airplanes due to loss of control, the NASA Aviation Safety Program has conducted research into flight control technologies that can provide resilient control of airplanes under adverse flight conditions, including damage and failure. As part of the safety program s Integrated Resilient Aircraft Control Project, the NASA Airborne Subscale Transport Aircraft Research system was designed to address the challenges associated with the safe and efficient subscale flight testing of research control laws under adverse flight conditions. This paper presents the results of a series of pilot evaluations of several flight control algorithms used during an offset-to-landing task conducted at altitude. The purpose of this investigation was to assess the ability of various flight control technologies to prevent loss of control as stability and control characteristics were degraded. During the course of 8 research flights, data were recorded while one task was repeatedly executed by a single evaluation pilot. Two generic failures, which degraded stability and control characteristics, were simulated inflight for each of the 9 different flight control laws that were tested. The flight control laws included three different adaptive control methodologies, several linear multivariable designs, a linear robust design, a linear stability augmentation system, and a direct open-loop control mode. Based on pilot Cooper-Harper Ratings obtained for this test, the adaptive flight control laws provided the greatest overall benefit for the stability and control degradation scenarios that were considered. Also, all controllers tested provided a significant improvement in handling qualities over the direct open-loop control mode.
Synthesis of leukotrienes by freshly harvested endothelial cells.

Abstract Endothelial cells produce endothelin, a powerful vasoconstrictor. We report the release of additional vasoconstrictor material in conditional filtrate from freshly harvested cells, which we identified as leukotrienes by radioimmunoassay (RIA) and by high pressure liquid chromotography (HPLC). The material was collected in cell free filtrates by superfusion of freshly harvested bovine endothelial cells attached to cytodex-3 microcarrier beads. Cells and beads form a dense network on filter paper permitting collection of cell free filtrate. The amount of leukotrienes in conditioned filtrate was 158 ± 21 picograms/million cells. The calcium ionophore A23187 stimulated the release of leukotrienes (392.0 ± 47.6). The peak of leukotriene production occurred within an hour after incubation of cells slowly declining thereafter. Conditioned filtrate to which indomethacian had been added caused coronary vasoconstriction in the perfused rat heart preparation, as did synthetic leukotrienes C + , D + and E + . It was found by RIA and HPLC that some of the constrictor effect of conditioned filtrate derived from leukotrienes.
Traffic control in ATM networks

Abstract This paper presents a framework to study the problem of traffic control in ATM networks. Bursty traffic sources are modelled by Interrupted Bernoulli Processes. Probability of violation and dimensioning issues are addressed for the leaky bucket mechanism and the (L,M,T) mechanism, proposed by the authors. We present two schemes to demonstrate that improved statistical multiplexing can be achieved if the traffic control mechanisms are not used in isolation for each session, rather they are used on groups of sessions. In the first scheme, traffic control is performed on the aggregate traffic of a group. In the second scheme, traffic control is performed on single sessions with information about the status of all the sessions of the group being available and used at each traffic control mechanism. Numerical examples that illustrate the improvement in statistical multiplexing as a result of the above schemes are presented.
Rethinking the Canonical Text of Pushkin’s Boris Godunov

O f all the magnificent poetry and prose written by Alexander Pushkin, his personal favorite was Boris Godunov-an historical drama set in early modern Russia's darkest hour, the "Time of Troubles" (1598-1613).1 Boris Godunov was Pushkin's "most ambitiously planned" and "most carefully executed work," and it was considered by the poet to be his magnum opus. Although the play is generally considered to be "one of the great masterpieces of Russian drama," it puzzled many of Pushkin's contemporaries and is still considered to be "problematic" if not downright "incomprehensible" by leading scholars and critics.2 How then can we explain Pushkin's own strong attachment to the play? This article will attempt to provide some answers by focusing on the original version of Boris Godunov, completed in 1825, which greatly pleased and excited Pushkin's contemporaries, rather than the far less popular censored version published in 1831-the text usually studied by scholars. To this day Pushkin's original play remains virtually unknown and has generally been ignored even by critics and scholars aware of its existence. Careful examination of the original play, Pushkin's own historical perspective on the events of the Time of Troubles, and the peculiar circumstances in which he wrote Boris Godunov will not only help explain why it was the poet's favorite work but also demonstrate the need to rethink some basic
Does Campaign Length Matter? Testing for Cross-National Effects

Our findings suggest that there are systematic differences in the ways that voters use the real values of economic variables when casting a vote depending on how long they have had to learn about the true state of the economy. It is possible that in campaigns of sufficient length voters may have more time to be exposed to competing campaign messages and to learn about the true state of the economy and the true policy positions of candidates. We tested this assertion on 113 elections in thirteen democracies. The test results in a confirmation of the hypothesis. In longer campaigns, voters rely more heavily on the true values of economic conditions to inform their evaluations of parties in power. In shorter campaigns, these effects are mostly absent. Campaign length seems to matter for voter learning.
The people's liberation movement in Bosnia and hercegovina, 1941–45: What did it mean to fight for a multi‐national state?

How is it possible to build a nation‐state from a country inhabited by three nations, rather than one principal nation? To liberate this country from its neighbours yet at the same time unite it with them? To lead a national‐liberation movement encompassing nationalist extremists from opposing camps? These questions confronted the Communist Party of Yugoslavia in Bosnia and Hercegovina during World War II, when it successfully defeated the German and Italian invaders and Serb and Croat extremists (Chetniks and Ustasas) to found the Republic of Bosnia and Hercegovina as a member of the federal Yugoslav state. The untold story of this victory, seemingly against all odds, is the subject of this article.
A STRUCTURED APPROACH TO THE AUTOMATIC PLANNING OF MACHINING OPERATIONS FOR ROTATIONAL PARTS BASED ON COMPUTER INTEGRATION OF STANDARD DESIGN AND PROCESS DATA

The traditional procedure for developing a manufacturing process plan involves a number of interconnected steps beginning with the initial design and culminating in the instructions for the machine that makes the part. When performed manually, the procedure is very tedious, time consuming, and often, inconsistent. This paper presents an alternative method, called the Automated Machining-Operations Process-Planning System (AMOPPS), to automatically generate the process plan and the numerical control (NC) instructions to machine a part that has been previously designed by a computer-aided design (CAD) system. AMOPPS combines preset planning logic and data from three databases (viz., workpiece material, machine tool, and cutting tool) with appropriate data from a CAD database and information from the user about the workpiece to calculate the optimal machining parameters, print a process plan, print the corresponding NC program listing, and provide an on-screen animation of the cutting passes. Although AMOPPS is a prototype, it can be extended by adding other modules, and it does provide a structure through which a fully integrated manufacturing system can be developed.
IM-08INFLAMMATION DRIVER, NF-kB, IS ASSOCIATED WITH POOR OUTCOME GROUP A EPENDYMOMA AND REGULATES A KEY IMMUNE SUPPRESSIVE SIGNALING PATHWAY INVOLVED IN THE TUMOR MICROENVIRONMENT.

Inflammation has been identified as a hallmark of high-risk Group A ependymoma (EPN). An initial study from our lab showed Group A was distinguished from Group B by an inflammatory immune phenotype. Given that inflammation has been identified as a causative factor in a number of other tumor types we concluded that Group A may also be influenced by inflammation. Investigation of this hypothesis revealed that tumor cells were releasing an inflammation-associated protein called interleukin-6 (IL-6). This converted surrounding myeloid cells in the tumor to release inflammatory effector IL-8 via activation of a key tumor cell and immune cell functional regulator called STAT3. We sought to investigate the mechanism driving IL-6 production in Group A EPN. We analyzed our molecular dataset and identified genes that are dysregulated in Group A EPN compared to other EPN subtypes and additionally are also dysregulated compared to all other childhood brain tumor types. A large number of these genes are associated with NF-kB activity, also a regulator of inflammation, which is known to drive IL-6 production. We also found that one gene was significantly underexpressed in Group A EPN than all other tumor types, LDOC1, a known suppressor of NF-kB transcription. This provided rationale to explore NF-kB signaling and its role in driving inflammation in Group A EPN. Using our newly developed Group A EPN line, 811, we found loss of NF-kB, through genetic knockdown of RELA, a key NF-kB protein, decreased proliferation and induced apoptosis. Furthermore, loss of NF-kB resulted in decreased STAT3 signaling suggesting its role in driving the inflammatory signaling. We conclude that NF-kB to important in Group A EPN survival and is implicated in the immune suppressive phenotype observed in Group A. Effective design of Group A-targeted immunotherapy for children with EPN may require blockade of this potentially immunosuppressive pathway.
Effusion chemistry in the GaTe-Ga system

Abstract Gallium telluride is an important example for understanding the high temperature chemistry of III–VI phases. It is used in optical recording devices and a variety of thin-film ternary-phase applications. In this work, the vaporization chemistry and vapor pressure of Ga-Te samples with initial mole fractions of Te of 0.503 ± 0.002 and 0.436 ± 0.003 were studied in the temperature range 921–1102 K by the simultaneous Knudsen effusion and Volmer (torsion) effusion method. A new phase, GaTe0.96 ± 0.02(s), was discovered and modification to published phase diagrams of Ga-Te was made. Two quadruple points were observed: [liquid (L2) with 10mol% Te, monotectic liquid (L1) with 30 mol% Te, GaTe0.096 ± 0.02(s), and vapor at 1029 ± 12 K and 0.22(+0.10/−0.09) Pa]; [(L2), GaTe0.96 ± 0.02(s), GaTe(s), and vapor at 968 ± 42 and 0.026(+0.094/−0.022)Pa]. Chemical analyses of starting materials and residues showed the effusion of GaTe(s) and GaTe0.96 ± 0.02(s) to be incongruent, but that of the latter is very close to being congruent. Vaporization reactions and their ΔH°(298K) were established in five composition and temperature ranges. On the basis that ΔH°(298 K) of GaTe(s) and 1 2Te 2 (g) are −78.8 ± 2.4 and 84.2 ± 0.4 kJmol−1, respectively, then the ΔH°(298K) of GaTe(s) and GaTe0.96 ± 0.02(s) are −104 ± 15 and −101 ± 15 kJ mol−1, respectively.
A new one-point quadrature, quadrilateral shell element with drilling degrees of freedom

Abstract In this paper we discuss the development of a new four-node general shell element with single point quadrature used for the analysis of non-linear geometrical and material problems. One of the main features of the present development is the implementation of a rotation component around the shell normal (i.e. drilling rotation) to Belytschko's family of shell elements. Thus, at each node, six degrees of freedom (i.e. three translations and three rotations) make the element easy to connect to space beams, stiffeners or intersecting shells. A projection scheme for warping correction is proposed so that the element is accurate for both flat and warped configurations. All locking phenomena (such as transverse shear, in-plane shear and membrane locking) are controlled by an assumed strain method. Also, a physical stabilization approach for control of spurious zero-energy modes is proposed without requiring any artificial stabilization parameters. This approach is inexpensive and accurate because it updates and stores hourglass stresses only at the mid-surface rather than at all the integration points through the shell thickness. To demonstrate the features of the new shell element, it was applied to the analysis of large-scale, non-linear, static, dynamic and impact problems using elastic, isotropic/anisotropic elastoplastic and composite damage models. The element performed well for the problems that sometimes cause difficulties for other shell element techniques.
Candidate THz sources: The history and future (?) of velocity-modulated devices

Compelling applications for terahertz technology include medical diagnostics and imaging, extremely wideband communication (XWB), pollution monitoring and security threat detection. One impediment is a lack of practical sources in the 1-10THz frequency range. Room-temperature CW operation, high spectral purity, tunability, and power levels above the milliwatt range are additional requirements that compound the challenge. Continued scaling of feature sizes will enable traditional semiconductor devices to provide good small-signal performance at THz frequencies, but practically obtaining the desired output power levels is much less certain. Traditional coherent optical sources encounter downward frequency scaling difficulties as the energy state differences approach 25meV (corresponding to approximately 6THz, or 50μm free-space wavelength). Electronic devices dependent on velocity modulation obey rather different scaling laws and are strong candidates for bridging the "terahertz gap." As relatively few contemporary engineers are familiar with vacuum electronic devices (VEDs), and fewer still with velocity modulation, this paper reviews the history of velocity-modulated VEDs, starting with the observations of Barkhausen and Kurz in 1919, and proceeding to practical devices, such as the klystron, magnetron, traveling-wave tube (TWT) and backward-wave oscillator (BWO). We additionally consider how modern process technology enables a reconceiving of classical VEDs to produce devices capable of practical operation in the 1-10THz region.
Pink and Blue Collar Jobs: Children's Judgments of Job Status and Job Aspirations in Relation to Sex of Worker

Past work shows that even young children know that occupations are differentially linked to men and women in our society. In our research, we studied whether 6- and 11-year-old children's (a) beliefs about job status and (b) job interests would be affected by the gendered nature of jobs. When asked about familiar occupations, children gave higher status ratings to masculine jobs and expressed greater interest in jobs culturally associated with their own sex. To circumvent the extant confounds between job gender and job status in our culture, we also developed a new methodology in which novel jobs were portrayed with either male or female workers. Older children rated novel jobs portrayed with male workers as having higher status than the identical jobs portrayed with female workers. Portrayal sex had no effect on children's own interests in these novel jobs at either age. Methodological, theoretical, and educational issues are discussed in relation to sex-role development and vocational aspirations.
A spin-label assay for metal ion chelation and complex formation.

Abstract The electron spin resonance (ESR) lines of nitroxide spin labels are broadened by electron spin exchange reactions that take place during collisions with paramagnetic ions. The degree of line broadening is greatly reduced when the paramagnetic ion forms a coordination bond with certain functional groups on organic molecules. These observations form the basis for a spin-label assay for metal ion chelation and complex formation. This paper describes the characteristics of such an assay for divalent nickel ions and the spin label TEMPONE (2,2,6,6-tetramethylpiperidone-N-oxyl). The chelation of Ni2+ by cysteine and the interaction of Ni2+ with sodium dodecyl sulfate micelles and phospholipid vesicles are demonstrated. In addition to monitoring interactions of paramagnetic ions, the assay also allows the detection of interactions of nonparamagnetic ions that compete with the paramagnetic ions for binding sites. A kinetic analysis of competition between Ni2+ and Zn2+ ions for binding sites on phospholipid vesicles is presented. There are several advantages of the spin-label line-broadening assay compared to other conventional assays for metal chelation and complex formation. The line-broadening assay does not require that the sample be optically clear or chemically defined, it requires only very small quantities of material, it can detect as little as 0.4 to 1 μmol of complexing agent, and it may be utilized in complex biological systems including subcellular organelles and macromolecules.
On precision droplet-based net-form manufacturing technology

AbstractHigh-precision droplet-based net-form manufacturing of structural components is gaining considerable academic and industrial interest owing to the promise of improved component quality resulting from rapid solidification processing and the economic benefits associated with fabricating a structural component in one integrated operation. A droplet-based net-form manufacturing technique is under development by the authors which is termed precision droplet-based net-form manufacturing (PDM). As the technique exploits the capillary instability phenomenon of liquid jets for producing uniform liquid metal droplets, it allows for a greater control of the thermal state and mass flux of the droplets and thus the microstructure of the deposit can be readily tailored. The principle and the associated technical issues are described and discussed in detail in this paper. Recent progress in the development of PDM is also presented. The preliminary results demonstrated the following four important facts: (a) molt...
The Nepali State and the Dynamics of the Maoist Insurgency

In contrast to existing quantitative studies of the civil conflict in Nepal, we argue that combinations of motive and opportunity were crucial for the development of the Maoist insurgency and that these conditions stem largely from the nature of the Nepali state. The decade-long insurgency was characterized by two distinct dynamics. In the initiation period of the war (1996–2000), the insurgency was driven largely by newly enabled Maoist organizers capitalizing on the caste, ethnic, and economic divisions that had been codified over time by autocratic state-building efforts. In the more violent and geographically widespread maturation period of the war (2001–2006), the insurgency depended less on historical grievances than on the motivation of rebels and sympathizers by the often-indiscriminate violence perpetrated by the besieged Nepali state. We provide empirical evidence for this argument in a narrative section that contextualizes the Maoist insurgency as well as in a fuzzy-set qualitative comparative analysis (fsQCA) of data for the 75 Nepali districts in the two periods of the insurgency. fsQCA allows for the assessment of how combinations of the largely state-generated motivations and opportunities affected the dynamics of the insurgency.
Statistical thermodynamics of nonstoichiometry in nonmetallic binary compounds

Abstract A statistical thermodynamic analysis is given for an ordered, nonmetallic compound MX in which the predominant atomic point defects are vacancies. These are associated with singly-ionizable donor and acceptor levels and are assumed to be distributed at random over the available sites. Conduction band electrons and valence band holes are considered to be present. The partition function for the Gibbs free energy is constructed as the sum of two parts: A configurational entropy times the temperature and an excess Gibbs free energy. Utilizing the fact that both these parts must be homogeneous functions of the first degree in the numbers of defects of each kind, fixes the composition dependence of the excess Gibbs free energy when expressed accurate to the 1st power of the defect numbers and forces the densities of states in the conduction and valence bands to be expressed as functions of the numbers of defects. The resulting equations reduce to those previously obtained only in the case of nondegenerate semiconductor with small defect concentrations.
Enzyme immobilization on grafted polymeric microspheres

Abstract Radiation-mediated grafting of polyacrolein onto poly(methyl methacrylate) microspheres has been shown to activate the particles for chymotrypsin (EC 3.4.21.1) immobilization. Treatment of porous polystyrene/magnetite particles with polyacrolein produced very small enzyme loading enhancement and significantly increased substrate diffusional resistance.
Synthesis, biological activity, and DNA-damage profile of platinum-threading intercalator conjugates designed to target adenine.

PT-ACRAMTU {[PtCl(en)(ACRAMTU)](NO3)2, 2; ACRAMTU = 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea, 1, en = ethane-1,2-diamine} is the prototype of a series of DNA-targeted adenine-affinic dual intercalating/platinating agents. Several novel 4,9-disubstituted acridines and the corresponding platinum−acridine conjugates were synthesized. The newly introduced 4-carboxamide side chains contain H-bond donor/acceptor functions designed to promote groove- and sequence-specific platinum binding. In HL-60 (leukemia) and H460 (lung) cancer cells, IC50 values in the micromolar to millimolar range were observed. Several of the intercalators show enhanced cytotoxicity compared to prototype 1, but conjugate 2 appears to be the most potent hybrid agent. Enzymatic digestion assays in conjunction with liquid chromatography−electrospray mass spectrometry analysis indicate that the new conjugates produce PT-ACRAMTU-type DNA damage. Platinum-modified 2‘-deoxyguanosine, dG*, and several dinucleotide fragments, d(NpN)*, ...
Interaction of T3 and carbohydrate in the induction of lipogenic enzymes.

Abstract The response of hepatic lipogenic enzymes to T3 in animals on a regular diet is amplified. On a high carbohydrate diet the response becomes linear with a leftward shift in the T3 dose response curve. This interaction between thyroid hormone and carbohydrate feeding is not a primary result of an increase in insulin secretion. Additional studies in the aging animal have shown that the known decline in basal lipogenic enzymes is paralleled by a decline in response to thyroid hormone as well as a decline in response to carbohydrate feeding. Nevertheless, the amplification phenomenon persists suggesting that T3 interacts with a carbohydrate generated signal in a multiplicative fashion. The decline in response to T3 and carbohydrates is probably due to an age-related decrease in the generation of this signal. Preliminary studies in isolated hepatocytes have shown that increases in glucose concentrations perse can induce malic enzyme. These cells also exhibit a multiplicative interaction between T3 and glucose.
Computational photography and compressive holography

As lasers, photosensors, and computational imaging techniques improve, holography becomes an increasingly attractive approach for imaging applications largely reserved for photography. For the same illumination energy, we show that holography and photography have nearly identical noise performance. Because the coherent field is two dimensional outside of a source, there is ambiguity in inferring the three-dimensional structure of a source from the coherent field. Compressive holography overcomes this limitation by imposing sparsity constraints on the three-dimensional scatterer, which greatly reduces the number of possibilities allowing reliable inference of structure. We demonstrate the use of compressive holography to infer the three-dimensional structure of a scene comprising two toys.
Progress in Science and Science at the Non-Western Peripheries

Assuming that progress in science means effectiveness at problem-solving, this paper discusses how a progressive scienti?c tradition can be created by a peripheral scienti?c community. A mechanism of peripheral scienti?c growth is proposed, and it is illustrated with an Indian case study. The conclusion of the paper is that scienti?c collaboration between metropolitan and peripheral research communities is frequently characterized by a persistent inequality of intellectual authority due to inequalityin their epistemic transactions.
Enhancing adherence to combination antiretroviral therapy in non-adherent HIV-positive men

This paper describes a preliminary study aimed at testing the efficacy of a brief medication counselling and behavioural intervention in improving adherence to combination antiretroviral medication therapy and prophylactic treatment among non-adherent men living with HIV. Twenty-one non-adherent HIV-positive men obtaining primary care clinical services at a Veterans Affairs Medical Center were recruited by health care providers. Intervention participants were primarily African-Americans with histories of intravenous drug use. During a period of five months, participants were provided with monthly medication counselling and a weekly medication pill organizer. Participants were compared with 21 non-adherent matched controls receiving standard pharmacy care including review of medications. Intervention and control subjects were compared on several variables: medication refill timeliness, appointment attendance, hospitalizations and opportunistic infections. Medical information was obtained from hospital and pharmacy records at baseline and post-intervention. Pre- to post-intervention rates of adherence to medication refills and clinic appointments increased significantly among intervention participants. Relative to matched controls, intervention participants also significantly increased drop-in visits and showed fewer hospitalizations. Intervention participants also showed significant decreases in the number of opportunistic infections. Results suggest that exposure to medication counselling and behavioural interventions increase adherence, with associated reductions in negative clinical outcomes.
Neonatal cord serum levels of ob (Obese) gene product `leptin'(LPT) : Its relationship to birth weight, gestational age, maternal diabetes and obesity. † 417

Neonatal cord serum levels of ob (Obese) gene product `leptin'(LPT) : Its relationship to birth weight, gestational age, maternal diabetes and obesity. † 417
The World Bank ' s Africa Virtual University Project: a revisit

Purpose – The main purpose of using technology in the delivery of virtual learning programs in higher education in Africa is to ensure access and equity as a strategy to develop human resources. Examining how specific educational innovations in higher education are working is necessary. The purpose of this study is to examine the World Bank ' s education policies in Africa with special focus on AVU Kenyatta University Project. In addition, the paper seeks to critically examine the use of information technology (IT) distance learning project initiated by the World Bank in Kenya. The project served as an important pioneering role to eLearning in Africa. Design/methodology/approach – To achieve the primary purpose of the study, a critical analysis of relevant literature was conducted. The literature search included computerized search of accessible and available material on AVU and distance education in Africa. Findings – The results of the study show that AVU ' s design and implementation in Africa was init...
Investigation of induced circular dichroism of benzo(a)pyrene cyclodextrin complexes

This study focuses on the inclusion complexes of α-,β- andγ-cyclodextrins with benzo (a) pyrene, as indicated by induced circular dichroism data. The benzo(a)pyrene complex exhibits a significant induced ellipticity in the presence ofγ-cyclodextrin, while the other two cyclodextrins did not produce a significant induced circular dichroism signal. In the presence of deuterium oxide, which is larger than the water molecule, the ellipticity is larger. The changes in ellipticity with increasing cyclodextrin concentration are observed to follow the changes in equilibrium of the pyrene-γ-cyclodextrin system. The study of these systems using circular dichroism measurements yields a method of estimating the possible stoichiometry of this complex.
Very efficient fluorescent background suppression in confocal Raman microscopy

Time-gated optical imaging is employed for the first time to achieve confocal Raman microscopy. The innovative laser design and a careful selection of the Kerr-gate material allows to reduce fluorescent background by 1000 times.
Exposure to Community Violence: Processes That Increase the Risk for Inner-City Middle School Children

An ecologically framed model is presented describing processes accounting for early adolescents' exposure to community violence in high-risk neighborhoods as a function of risk factors in four ecological domains assessed in the prior year. The model was tested for hypothesized pathways along which the combined domains of risk might operate. The children were interviewed about their exposure to community violence. Data on the risk factors were obtained from the children themselves and their parents, classmates, and teachers. All four domains--family and household context, negative parenting, deviant behavior of friends, and the children's own behavioral characteristics and cognition--contributed to the children's risk for exposure 1 year later. As hypothesized, deviant behavior of friends and the children's own behavior and cognition were found to mediate the effects of stressful family and household context and negative parenting on later risk for exposure.