cssi/SciSciGPT-SciSciNet huggingface dataset:
Computational analysis of GAL pathway pinpoints mechanisms underlying natural variation

Quantitative traits such as human height are measurable phenotypes that show continuous variation over a wide phenotypic range. Enormous effort has recently been put into determining the genetic influences on a variety of quantitative traits, including human genetic diseases, with mixed success. We identified a quantitative trait in a tractable model system, the GAL pathway in yeast, which controls the uptake and metabolism of the sugar galactose. GAL pathway activation depends both on galactose concentration and on the concentrations of competing, preferred sugars such as glucose. Natural yeast isolates show substantial variation in the behavior of the pathway. All studied yeast strains exhibit bimodal responses relative to external galactose concentration, i.e. a set of galactose concentrations existed at which both GAL-induced and GAL-repressed subpopulations were observed. However, these concentrations differed in different strains. We built a mechanistic model of the GAL pathway and identified parameters that are plausible candidates for capturing the phenotypic features of a set of strains including standard lab strains, natural variants, and mutants. In silico perturbation of these parameters identified variation in the intracellular galactose sensor, Gal3p, the negative feedback node within the GAL regulatory network, Gal80p, and the hexose transporters, HXT, as the main sources of the bimodal range variation. We were able to switch the phenotype of individual yeast strains in silico by tuning parameters related to these three elements. Determining the basis for these behavioral differences may give insight into how the GAL pathway processes information, and into the evolution of nutrient metabolism preferences in different strains. More generally, our method of identifying the key parameters that explain phenotypic variation in this system should be generally applicable to other quantitative traits. Author summaryMicrobes adopt elaborate strategies for the preferred uptake and use of nutrients to cope with complex and fluctuating environments. As a result, yeast strains originating from different ecological niches show significant variation in the way they induce genes in the galactose metabolism (GAL) pathway in response to nutrient signals. To identify the mechanistic sources of this variation, we built a mathematical model to simulate the dynamics of the galactose metabolic regulation network, and studied how parameters with different biological implications contributed to the natural variation. We found that variations in the behavior of the galactose sensor Gal3p, the negative feedback node Gal80p, and the hexose transporters HXT were critical elements in the GAL pathway response. Tuning single parameters in silico was sufficient to achieve phenotype switching between different yeast strains. Our computational approach should be generally useful to help pinpoint the genetic and molecular bases of natural variation in other systems.
Differential effects of recent versus past traumas on mood, social support, binge drinking, emotional eating and BMI, and on neural responses to acute stress.

Traumatic stress is associated with risk of psychiatric and physical illnesses. However, the differential and separable effects of past versus recent traumas on maladaptive coping and neural respon...
The Role of Top Management Team Cognitive Diversity in a Global Sample of Innovative Firms: A Review

This chapter used secondary sources to examine the role of cognitive diversity among top management teams in a global sample of 38 innovative firms (19 headquartered in the United States and 19 headquartered in other countries). Top management team demographics—generation, firm tenure, gender, and race—were collected, and firms were classified into four business life cycles. Firms in the Maturity phase had less generational and geographic dispersion, but more gender and racial diversity, so that cognitive diversity might facilitate continuous innovation aimed at marketplace relevancy. Innovative Start-ups were geographically dispersed but more cohort, gender, and racially concentrated. Perhaps this lack of cognitive diversity was necessary to maintain focus on the new business for survival in the early years. Limitations and future research directions were presented.
Propofol-induced uric acid crystals: A case of cloudy urine

Propofol is an intravenous anesthetic agent commonly used intraoperatively as well as in the intensive care unit. Known short-term effects of propofol can include apnea, hypotension, and bradycardia. In children, the rarer adverse sequelae of intravenous anesthetics have received little attention. We present the case of a thirteen-year-old male who incidentally developed uric acid crystals in his urine following a short-duration propofol infusion.
Exploring the Association between Multimorbidity and Cognitive Impairment in Older Adults Living in the Community: A Review of the Literature:

Two-thirds of older adults have multimorbidity (MM), or co-occurrence of two or more medical conditions. Mild cognitive impairment (CI) is found in almost 20% of older adults and can lead to furthe...
Constructing Robots for Undergraduate Projects Using Commodity Aluminum Build Systems

In this paper, we outline our experiences constructing two robots for undergraduate student projects using different commodity aluminum construction systems, Actobotics and goBilda. These building systems have gained popularity for use in high school robotics competitions. For our work, we adopt these modular build systems to construct robots used for undergraduate projects and as research robots. These building systems provide aluminum components that can be used to construct robot chassis and have the benefit of being reusable. We evaluate the benefits and drawbacks of each system. In addition to the evaluation of the construction systems used, we outline integration of embedded computers running ROS and the characteristics of each system.
Geriatric All-Terrain Vehicle Trauma: An Unhelmeted and Severely Injured Population.

BACKGROUND All-terrain vehicle (ATV) use is widespread, however, little is known about injury patterns and outcomes in geriatric patients. We hypothesized that geriatric patients would have distinct and more severe injuries than non-geriatric adults after ATV trauma. METHODS A retrospective cohort study was performed using the National Trauma Databank comparing non-geriatric (18-64) and geriatric adults (≥65) presenting after ATV trauma at Level 1 and 2 trauma centers from 2011 to 2015. Demographic, admission, and outcomes data were collected, including injury severity score (ISS), abbreviated injury scale (AIS) score, discharge disposition, and mortality. We performed univariate statistical tests between cohorts and multiple logistic regression models to assess for risk factors associated with severe injury (ISS>15) and mortality. RESULTS 23,568 ATV trauma patients were identified, of whom 1,954 (8.3%) were geriatric. Geriatric patients had higher rates of severe injury(29.2 v 22.5%,p 3) (36.2 vs 30.2%,p<0.001). Helmet use was significantly lower in geriatric patients (12.0 v 22.8%,p<0.0001). On multivariate analysis age increased the odds for both severe injury (OR 1.50, 95% CI 1.31-1.72, p<0.0001) and mortality (OR 5.07, 95% CI 3.42-7.50, p<0.0001). CONCLUSIONS While severe injury and mortality after ATV trauma occurred in all adults, geriatric adults suffered distinct injury patterns and were at greater risk for severe injury and mortality. LEVEL OF EVIDENCE Level IV STUDY TYPE: Retrospective review of National Database.
Latinos and the Skin Color Paradox

For African Americans and Latinos, skin color is a significant predictor of many social and economic stratification variables including income, education, housing, occupational status, spousal status, poverty rates, criminal justice sentencing, and rates of depression. Given these patterns, some scholars have surprisingly found that skin color is not a significant predictor of many political attitudes for African Americans, and called this phenomenon the “skin color paradox.” This article investigates the role of skin color, race, and national origin in predicting political marginality and political commonality among Latinos. The models suggest that skin color is not a significant predictor of political attitudes, consistent with the skin color paradox theory but that national origin does predict some political attitudes.
Temporal Compositional Processing by a DSOM Hierarchical Model

Any intelligent system, whether human or robotic, must be capable of dealing with patterns over time. Temporal pattern processing can be achieved if the system has a short-term memory capacity (STM) so that different representations can be maintained for some time. In this work we propose a neural model wherein STM is realized by leaky integrators in a self-organizing system. The model exhibits compositionality, that is, it has the ability to extract and construct progressively complex and structured associations in an hierarchical manner, starting with basic and primitive (temporal) elements.
Brazing Alloy Design for Metal/Ceramic Joints

Etude de l'assemblage des ceramiques par brasage et choix de l'alliage utilise. Les resultats d'essais de mouillage sur le nitrure de silicium montrent que Ti et Zr sont des additifs interessants pour ces alliages. On presente les resultats de l'analyse microstructurale, de la MEB et de l'analyse par microsonde electronique des echantillons mouilles
Time to positivity for detection of bacteremia in neonates.

The blood culture results of all samples obtained from newborns at Grady Memorial Hospital, Atlanta, Ga., during a 6-month period were analyzed to determine the time required for a blood culture to become positive, the time at which a culture could safely be considered negative, and the spectrum of isolated organisms. During the study period, 1,248 samples were submitted from all nurseries and processed by an automated detection instrument (BACTEC NR660). Of the 1,248 samples, 98 (7.8%) were positive by the end of a 7-day processing period; 29 of the 98 were classified as definite bacterial pathogens, 52 were classified as possible bacterial pathogens, 9 were classified as yeasts, and 8 were classified as contaminants. Virtually all organisms (28 of 29) categorized as definite pathogens were identified by day 2 of processing, and all were identified by day 4. All isolates of group B streptococcus, Escherichia coli, Klebsiella species, and Staphylococcus aureus were identified by day 2. Of all positive blood cultures, 79% were identified by day 2, 88% were identified by day 3, and 94% were identified by day 4. Of the 21 isolates identified after day 2, the only definite pathogen was from a sick baby in the intensive care unit. From among the 870 term low-risk newborns cultured because of maternal risk factors, only four possible pathogens were identified after day 2. The positive and negative predictive values of blood culture at days 2 and 4 were 92 and 99%, respectively.We conclude that, in our institution, (i) a 2-day processing period is sufficient to detect positive blood cultures in the asymptomatic term infant, (ii) a 4-day processing period will detect virtually all clinically important infections, and (iii) clinical yield from continuing blood culture processing beyond 4 days does not justify the time and cost involved.
Position Statement: Increasing Test Coverage in a VLSI Design Course

It is argued that test and verification (validation) have a lot in common. The test problem is a (small) subset I of the verification problem. The concept of justification is useful for both problems. Practical formal Bbolean equivalence checking tools draw heavily on algorithms from the test field. ATPG techniqu~s are beginning to be applied to other verification problems. A VLSI design course should, therefore, emphasize both manufacturing test and design verification as necessary to produce a quality ptoduct, and these topics should comprise a significant part of the content of the course.
Spectroscopic characterization of Pr 3+ :ZnSe crystals fabricated via post-growth thermal diffusion

We demonstrate post-growth thermal diffusion rates of praseodymium ions into ZnSe. Near and middle infrared luminescence spectra and kinetics of Pr:ZnSe crystals were studied at RT.
The electrical properties of dislocations in silicon—I: The effects on carrier lifetime

Abstract Lifetime measurements were made on both n-type and p-type silicon which contained dislocation densities of the order of 107 per cm2. The dislocations were introduced by plastic deformation at 750°. A theory for transient recombination, based on R ead 's hypothesis of a potential barrier at the dislocation, is developed to explain the experimental data. The theory and the measurements show that the potential barrier inhibits the capture of majority carriers causing long lifetimes to be observed. Also, it is shown that for small excess carrier densities, the lifetime is independent of the dislocation density and only weakly dependent on the majority carrier density. An analysis of the data in n-type silicon reveals that the dislocation has an acceptor level which is approximately 0.52 eV below the conduction band, and which has a capture cross section for electrons of approximately 10−15 cm2. In p-type silicon the dislocation is found to have a donor level whose location is not as well defined. The donor state was measured at 0.50 eV, 0.42 eV and 0.38 eV above the valence band in 200 Ω-cm, 50 Ω-cm, and 10 Ω-cm material respectively. The donor state's capture cross section for holes is about 10−16 cm2 for all three resistivities. It is suggested that in p-type material the donor states lie in a band rather than at a discrete level.
Feature selection for high-dimensional data: a fast correlation-based filter solution

Feature selection, as a preprocessing step to machine learning, is effective in reducing dimensionality, removing irrelevant data, increasing learning accuracy, and improving result comprehensibility. However, the recent increase of dimensionality of data poses a severe challenge to many existing feature selection methods with respect to efficiency and effectiveness. In this work, we introduce a novel concept, predominant correlation, and propose a fast filter method which can identify relevant features as well as redundancy among relevant features without pairwise correlation analysis. The efficiency and effectiveness of our method is demonstrated through extensive comparisons with other methods using real-world data of high dimensionality
Synaptotagmin SYTA Forms ER-Plasma Membrane Junctions that Are Recruited to Plasmodesmata for Plant Virus Movement

Summary Metazoan synaptotagmins are Ca 2+ sensors that regulate exocytosis and endocytosis in various cell types, notably in nerve and neuroendocrine cells [1, 2]. Recently, the structurally related extended synaptotagmins were shown to tether the cortical ER to the plasma membrane in human and yeast cells to maintain ER morphology and stabilize ER-plasma membrane (ER-PM) contact sites for intracellular lipid and Ca 2+ signaling [3, 4]. The Arabidopsis synaptotagmin SYTA regulates endocytosis and the ability of plant virus movement proteins (MPs) to alter plasmodesmata to promote virus cell-to-cell transport [5, 6]. Yet how MPs modify plasmodesmata, the cellular functions of SYTA and how these aid MP activity, and the proteins essential to form plant cell ER-PM contact sites remain unknown. We addressed these questions using an Arabidopsis SYTA knockdown line syta-1 and a Tobamovirus movement protein MP TVCV [5, 7]. We report here that SYTA localized to ER-PM contact sites. These sites were depleted and the ER network collapsed in syta-1 , and both reformed upon rescue with SYTA. MP TVCV accumulation in plasmodesmata, but not secretory trafficking, was also inhibited in syta-1 . During infection, MP TVCV recruited SYTA to plasmodesmata, and SYTA and the cortical ER were subsequently remodeled to form viral replication sites adjacent to plasmodesmata in which MP TVCV and SYTA directly interacted caged within ER membrane. SYTA also accumulated in plasmodesmata active in MP TVCV transport. Our findings show that SYTA is essential to form ER-PM contact sites and suggest that MPs interact with SYTA to recruit these sites to alter plasmodesmata for virus cell-to-cell movement.
Complex and Contradictory: The Doing of Gender on Regional Development Boards

Recognizing gender as a social construction, in this article we explore the complex, and in many ways contradictory, ‘doing’ of gender on regional development boards in Australia. While the number of women on these boards has risen over the past decade, the overwhelming sense of these organizations is one of homogeneity. The individuals on these ministerially appointed boards are awarded institutional privilege. Their roles provide them with status and benefits and their membership positions them as leaders within the (masculine) hegemony. This space is not, however, uniformly masculinized. With the limited resources at their disposal and little public recognition of their roles, the boards have limited agency. These poorly resourced boards are populated by women and men board members, while vested with important titles, are relatively powerless and are expected to undertake duties and display behaviour that is more consistent with a feminized role. The doing of gender can also be seen in the primacy of the economic over the social in regional development, where the economic is strongly associated with creating employment, especially in industries where men have traditionally dominated, rather than in the more feminized domains of services. This doing of gender points to the persistence of conservative gender patterns reinforcing a masculinized model of business. The contradiction here is that while they subscribe to this masculinized model, they are unable to deliver on outcomes because they do not have direct control over resources.
The algorithmic complexity of neural spike trains increases during focal seizures

The interspike interval spike trains of spontaneously active cortical neurons can display nonrandom internal structure. The degree of nonrandom structure can be quantified and was found to decrease during focal epileptic seizures. Greater statistical discrimination between the two physiological conditions (normal vs seizure) was obtained with measurements of context-free grammar complexity than by measures of the distribution of the interspike intervals such as the mean interval, its standard deviation, skewness, or kurtosis. An examination of fixed epoch data sets showed that two factors contribute to the complexity: the firing rate and the internal structure of the spike train. However, calculations with randomly shuffled surrogates of the original data sets showed that the complexity is not completely determined by the firing rate. The sequence-sensitive structure of the spike train is a significant contributor. By combining complexity measurements with statistically related surrogate data sets, it is possible to classify neurons according to the dynamical structure of their spike trains. This classification could not have been made on the basis of conventional distribution-determined measures. Computations with more sophisticated kinds of surrogate data show that the structure observed using complexity measures cannot be attributed to linearly correlated noise or to linearly correlated noise transformed by a static monotonic nonlinearity. The patterns in spike trains appear to reflect genuine nonlinear structure. The limitations of these results are also discussed. The results presented in this article do not, of themselves, establish the presence of a fine-structure encoding of neural information.
Creative Leadership: Making Good News

President Friedlaender, fellow members of the American Orthopaedic Association, colleagues, and distinguished guests: It is a tremendous honor and privilege for me to address you as the incoming president of the American Orthopaedic Association. The list of the 123 giants of our profession who have served in this role before me is truly awe-inspiring. I respect each of these individuals immensely for their contributions to our profession and I especially cherish and am eternally grateful to the handful from whom I have had the great fortune of receiving mentorship. I feel honored to have the opportunity to add my thoughts and comments to theirs, yet decidedly inadequate to live up to their legacies. Thus, it is with equal measures of excitement and trepidation that I speak this morning. As a means of introducing you to what I have termed creative leadership, as well as a base from which to construct the practical meaning of that term, I will share two brief stories: It is March 1865. In Glasgow, Scotland, Joseph Lister prepares to treat a patient with an open tibial fracture. In the Royal Glasgow Infirmary where Lister worked at the time, almost half of surgery patients died from infection. In some hospitals in Europe, as many as 80% died. While surgeons regretted this high death rate, they trained themselves to accept this unpleasant aspect of their work. After all, they thought, nothing could be done about these infections, because they arose spontaneously. Lister, however, was not convinced of the inevitability of infection. He turned against conventional wisdom and had, for some time, been searching for a way of preventing infection—an antisepsis method. Lister began this day by washing his hands and wearing clean clothes. Lister’s practices were scoffed at by most of his colleagues, who considered it a status …
The bauschinger effect of reverse yield stress reduction on radial crack growth of a cylindrical pressure vessel

Abstract A compressive hoop stress is often introduced intentionally in a high-pressure vessel to increase its resistance against fracture in radial directions. The effect is maximized when the hoop stress at the bore reaches the compressive yield stress. This autofrettage process becomes less effective if the compressive yield strength of the material decreases following a plastic strain in tension during pressurization. This reduction in compressive yield strength may cause reverse-yielding of the material near the bore. The adverse effect due to reverse-yielding on the subcritical crack growth characteristics of a radial crack emanating from the bore of a pressurized cylinder are studied in this paper. The explicit expression approximating crack-face nodal weight functions is used to compute the mode I stress intensity factors for a radial crack subject to a combination of internal pressure with complex residual stresses. The reduction of yield strength of high-strength steels may cause an increase in stress intensity by an order of magnitude for a shallow crack. The strain-hardening tends to reduce the adverse effect. An estimate of the effect on fatigue lives is also presented.
Age differences in inhibition: Possible causes and consequences

Abstract The relations among age, inhibition, perceptual speed, susceptibility to interference, and working memory were examined in a sample of 301 adults age 20 to 90. Younger adults were found to have more efficient inhibitory mechanisms than were older adults. Significant inhibition, however, was found in all age groups, including the older age group. Older adults were also found to be more susceptible to interference from irrelevant information. There was a small negative relation between interference and inhibition, suggesting that participants with the most efficient inhibitory functioning may be the least susceptible to interference. Perceptual speed, an index of processing efficiency, was found to mediate nearly all of the age-related variance in inhibition and interference. Interference, but not inhibition, was found to mediate some of the age-related variance in working memory.
Infrared spectroscopy of matrix-isolated carbon clusters, with emphasis on C8 and C9

Abstract Infrared spectra of neutral linear all-carbon clusters, produced by laser ablation of graphite, have been investigated in Ne, Ar and Kr matrices. The effects of thermal annealing on the infrared intensities have been used together with results from recent high level ab initio and density functional theory (DFT) calculations to locate several heretofore unknown infrared bands of linear C 8 and C 9 clusters. Specifically, two infrared bands located at 2071.5 cm −1 and 1710.5 cm −1 (Ar matrix), are shown to be well correlated and to match closely the density functional theory (DFT) predictions of 2109 cm −1 (1366.3 km/mol) and 1703 cm −1 (984.8 km/mol) by Hutter, Luthi and Diederich (HLD) for the linear C 8 cluster. A moderately intense band has also been located at 2078 cm −1 (Ar matrix) and its shown to correlate well with the two known C 9 bands at 1601 cm −1 and 1998 cm −1 . This band is also shown to match well with the DFT predictions of HLD and is assigned to the v 5 mode of linear C 9 . Combination bands involving symmetric and asymmetric stretching modes have been observed for C 5 , C 6 , C 7 and C 9 and are used to estimate the totally symmetric frequencies for these species. Good agreement with theory ios found. Finally, anharmonicity constants for the prominent asymmetric stretching frequencies are determined from the overtone bands of C 3 , C 5 , C 6 , C 7 and C 9 .
Remote sensing may provide unprecedented hydrological data

Basic hydrological research and water resources management may reap tremendous benefits from remote sensing technology, studies are showing. Satellite coverage may allow unprecedented accuracy in the quantification of the global hydrological cycle, for example. Yet despite such benefits, few hydrologists currently use such data. This is partly because the needed tools and algorithms are not fully developed. Such development requires field experiments that combine remotely sensed data with detailed in situ observations. AGU's Remote Sensing in Hydrology Committee has constructed a Web site (http://Iand.gsfc.nasa.gov/RSHC.html) that gives an overview of many such experiments. Included on the site is information on each experiment's overall goal, the types of in situ and remotely sensed measurements taken, relevant climate and vegetation conditions, and so forth. Links to additional relevant Web sites are included. The site is designed to be a suitable starting point for those interested in learning more about remote sensing in hydrology. It lists members of the committee who can be contacted for further information. Hydrologists have recognized the potential of remote sensing technology since the 1970s. It offers a way to avoid the logistical and economic difficulties associated with obtaining continuous in situ measurements of various hydrological variables, difficulties that are particularly pronounced in remote regions. Microwave instruments in particular can potentially provide all-weather, areally averaged estimates of certain variables (such as precipitation, soil moisture, and snow water content) that have been essentially unattainable in the past. In remote sensing, the conversion of emitted and reflected radiances into useful hydrological data is a complex problem. The measured radiances, for example, reflect the integrated character of a pixel area, a scale inconsistent with the point measurements of traditional hydrology. To develop the needed algorithms, field experiments must be designed that combine relevant satellite measurements with traditional in situ measurements in regions that are al- ready well understood hydrologically. Such field experiments can lead to the development of hydrological models that are driven with remotely sensed data. Once the performance of these models is deemed acceptable in the heavily monitored basins, they can be "transported" for use in regions having little or no in situ measurement system. Author,5: Randal D. Koster, Paul R. Houser and Edwin T. Engman, Hydrological Sciences Branch, Laboratory for Hydrospheric Process, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA; William P. Kustas, Hydrology Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland, USA.
Rheological investigation of the shear strength, durability, and recovery of alginate rafts formed by antacid medication in varying pH environments

Abstract The mechanical response of alginate rafts formed by mixing liquid alginate antacid medication (Gaviscon® Extra Strength Liquid Antacid) with acidic solutions was investigated by deforming isolated rafts in a shear rheometer. As rafts were deformed to varying magnitudes of applied strain, rheological parameters were identified and related to the overall strength, durability, and recoverability of rafts formed at different pH (1.1–1.7) and aging conditions (0.5–4 h). Rafts formed in the lowest acidity solutions (pH 1.4, 1.7) were elastically weak ( G ′ 0 = 60 , 42 Pa for un-aged raft) yet maintained their elasticity during applied shear deformation to large values of strain (γc ∼ 90%, 50%, where G′ ≈ G″), and displayed a low-to-moderate level of elastic recovery following large-strain deformation. Rafts formed in the highest acidity solution had the greatest strength ( G ′ 0 = 500 Pa for un-aged raft and 21.5 kPa for rafts after 0.5 h of aging), reduced durability (γc ∼ 2.5%, independent of aging), and displayed the greatest recoverability. A trade-off existed between un-aged raft strength and durability while recovery was dependent on durability, solution pH, and age. Rheometry-based evaluations of alginate rafts could be used for the informed design of future gastric retention and antacid products.
Omelets from pasteurized frozen whole egg by use of fresh freeze dried or spray dried egg white

Abstract Pasteurized frozen whole egg (PWE) was evaluated for use as the principle ingredient of omelets. Three types of omelets were used in the evaluation: plain, utilizing beaten whole egg; puffy, normally prepared with yolks and whites whipped separately; and 10-min omelets prepared similarly to puffy omelets except that 40g of flour was added. Sensory evaluation compared omelets made from PWE and reference omelets made from fresh eggs for acceptability, color, flavor, moistness, and tenderness. Scoring was from 0 to 6 with reference equal to 4.0. Color of plain omelets made from PWE was significantly darker than the reference omelets. Acceptability and other sensory factors of puffy and 10-min omelets made from PWE were not significantly different than comparable reference omelets when 17.3% of the pasteurized or fresh whole egg was replaced with fresh egg white or reconstituted freeze-dried egg white for leavening. Reconstituted spray-dried egg white required substitution of 23.1% of the PWE to produce puffy or 10-min omelets which were equal to reference omelets.
Kinematic GPS for Differential Positioning: Resolving Integer Ambiguities on the Fly

In kinematic GPS, the initial integer ambiguity must be resolved either by a static survey over time, or by instant calibration with a known baseline or an antenna exchange. While these standard methods require maintaining a baseline stationary to an earth-fixed reference frame during the initialization, there are situations when at least one of the receivers may be constantly in motion. This paper proposes two ideas for adapting standard kinematic techniques to situations that do not naturally allow for the constraint of a fixed baseline. The first calls for extracting the information needed to resolve the integer ambiguity from the very data collected while the kinematic survey is in progress. The second idea addresses the use of the antenna exchange technique for mobile platforms where the original locations of the antennas are not likely to remain stationary during the physical exchange. Both ideas count on information from additional measurements to augment their respective measurement models.
Information Literacy: The Missing Link in Early Childhood Education

The rapid growth of information over the last 30 or 40 years has made it impossible for educators to prepare students for the future without teaching them how to be effective information managers. The American Library Association refers to those students who manage information effectively as information literate. Information literacy instruction has been a priority in many secondary schools since the American Association of School Libraries published the Information Literacy Standards for Student Learning in 1998. Although these standards were written for grades K-12, information literacy is still not the focus in many early childhood classrooms. This article discusses the importance of information literacy instruction in early childhood education. Research suggests that early information literacy instruction, using informational texts and collaborative, teacher–librarian curriculum planning, promotes critical thinking and increases the ability to problem-solve—two skills necessary for survival in today’s Information Age.
Plant cellular responses to water deficit

Water availability and drought limit crop yields worldwide. The responses of plants to drought vary greatly depending on species and stress severity. These responses include changes in plant growth, accumulation of solutes, changes in carbon and nitrogen metabolism, and alterations in gene expression. In this article, we review cellular and molecular responses to water deficit, and their influence on plant dehydration tolerance.
Template-based procedures for neural network interpretation

Abstract Although neural networks often achieve impressive learning and generalization performance, their internal workings are typically all but impossible to decipher. This characteristic of the networks, their opacity , is one of the disadvantages of connectionism compared to more traditional, rule-oriented approaches to artificial intelligence. Without a thorough understanding of the network behavior, confidence in a system’s results is lowered, and the transfer of learned knowledge to other processing systems – including humans – is precluded. Methods that address the opacity problem by casting network weights in symbolic terms are commonly referred to as rule extraction techniques. This work describes a principled approach to symbolic rule extraction from standard multilayer feedforward networks based on the notion of weight templates , parameterized regions of weight space corresponding to specific symbolic expressions. With an appropriate choice of representation, we show how template parameters may be efficiently identified and instantiated to yield the optimal match to the actual weights of a unit. Depending on the requirements of the application domain, the approach can accommodate n -ary disjunctions and conjunctions with O( k ) complexity, simple n -of- m expressions with O( k 2 ) complexity, or more general classes of recursive n -of- m expressions with O( k L+ 2 ) complexity, where k is the number of inputs to an unit and L the recursion level of the expression class. Compared to other approaches in the literature, our method of rule extraction offers benefits in simplicity, computational performance, and overall flexibility. Simulation results on a variety of problems demonstrate the application of our procedures as well as the strengths and the weaknesses of our general approach.
Prostitution, AIDS, and preventive health behavior

Although considerable attention has been placed on the role of prostitutes in the AIDS epidemic, little attention has been directed to features of prostitutes' work lives which are relevant to the control of AIDS. This article reviews several aspects of prostitution in the United States which have implications for control of the epidemic. The article first reviews the epidemiology of human immunodeficiency virus (HIV) infection among prostitutes. The legalized system of prostitution in Nevada serves as a basis for comparison to illegal prostitution. This article examines the effectiveness of mandatory testing of prostitutes for monitoring and controlling the epidemic. And finally, a peer education approach as a means to control HIV infection among prostitutes is explored.
Brain and gastrointestinal cholecystokinin receptor family: structure and functional expression.

Abstract Cholecystokinin was one of the first gastrointestinal peptides discovered in the mammalian brain. In the central nervous system there is evidence for CCKA and CCKB receptor subtypes. The CCKA receptors occur in a few localized areas of the central and peripheral nervous systems where they modulate feeding and dopamine-induced behavior. CCKB receptors occur throughout the central nervous system where they modulate anxiety, analgesia, arousal, and neuroleptic activity. We have recently purified and cloned a CCKA receptor cDNA from rat pancreas that allowed isolation of an identical cDNA from rat brain by using the polymerase chain reaction. Using low-stringency hybridization screening of cDNA libraries from rat brain and AR42-J cells, which possess large numbers of CCKB receptors, we identified previously unreported cDNAs, the sequence of which were identical in both tissues. The cDNA sequence encodes a 452-amino acid protein that is 48% identical to the CCKA receptor and contains seven transmembrane domains characteristics of guanine nucleotide-binding regulatory protein-coupled receptors. COS-7 cells transfected with this cDNA expressed binding sites for agonists and antagonists characteristic of a CCKB receptor subtype. We conclude that this cDNA isolated from rat brain and AR42-J cells is a receptor of the CCKB subtype and that the respective cDNAs for both CCKA and CCKB are identical in the brain and gastrointestinal system.
Utilization of a formative evaluation card in a psychiatry clerkship.

This article discusses how formative feedback to medical students during their clinical rotations facilitates their successfully meeting the rotation’s educational objectives. To help students initiate mid-rotation feedback and to help preceptors structure that feedback, the authors designed the Instant Feedback Card (IFc). The goal of this study was to examine the degree to which the IFc facilitated the formative feedback process from the perspectives of both students and faculty. The IFc contains a checklist of the 13 clinical competencies that are also used to provide summative evaluations to students. One hundred and sixty-five medical students completing a 6-week psychiatry clerkship between January and December 2004 were given an IFc to present to their inpatient preceptor at one of their two inpatient sites. At the end of each 3-week inpatient rotation, all students were e-mailed a brief questionnaire about the formative feedback received during the preceding rotation. At the end of the 12-month study period, faculty were emailed a brief questionnaire about how useful the IFc was in helping to facilitate the feedback process. One hundred thirty-eight students (80%) participated in the study and returned 267 questionnaires (1.9/student, 97% response rate). Two hundred five students indicated on 77% of the questionnaires returned that they received mid-rotation feedback and of those, 84% revealed that feedback was helpful. Eighty-five percent of the students received mid-rotation feedback when they used the IFc and only 69% received mid-rotation feedback without the IFc. A majority of the 14 faculty serving as inpatient preceptors during the study period found the cards useful for stimulating feedback discussions, for reducing the stress of providing feedback and for getting students to request feedback. The results of this pilot study are not definitive, but they do indicate that the Instant Feedback card (IFc) did facilitate the process and structure of providing and receiving formative feedback as indicated by a significantly greater number of students receiving formative feedback when they used the IFc.
The Taylor-Proudman Balance and the Solar Rotational Data

For the Sun (and because of the presence of buoyancy), the implications of the Taylor-Proudman balance (TPB, a balance between the pressure, Coriolis, and buoyancy forces in the radial and latitudinal momentum equations) differ fundamentally from those of an incompressible fluid. The TPB now only determines the latitudinal variations of the solar entropy in terms of the rotation law and known functions of r. As a consequence of the TPB, the energy equation is in fact an equation for the angular velocity, Ω(r, θ)=Ω0(ω0(r)+ω2(r)P2(cos θ)), where P2(cos θ) is the second-order Legendre polynomial. In agreement with data from the Solar Oscillations Investigations project (SOI) Michelson Doppler Imager (MDI) on board SOHO, we assume that ω0(r) is constant with r, and solve the equation for ω2(r) with a simple, heuristic expression for the convective flux [if ω0(r) is constant, then ∂Ω/∂r vanishes for θc=547, P2(cos θc)=0, in remarkable agreement with Kosovichev's results inferred from isocontours for Ω(r, θ)]. For values of the meridional motions that are not too large, solutions for ω2(r) exist that agree with these isocontours. These solutions are such that the latitudinal variation of the convective flux, arising from the latitudinal variations of the entropy, required by the TPB, are significantly reduced.
Nanotechnology for missiles

Nanotechnology development is progressing very rapidly. Several billions of dollars have been invested in nanoscience research since 2000. Pioneering nanotechnology research efforts have been primarily conducted at research institutions and centers. This paper identifies developments in nanoscience and technology that could provide significant advances in missile systems applications. Nanotechnology offers opportunities in the areas of advanced materials for coatings, including thin-film optical coatings, light-weight, strong armor and missile structural components, embedded computing, and “smart” structures; nano-particles for explosives, warheads, turbine engine systems, and propellants to enhance missile propulsion; nano-sensors for autonomous chemical detection; and nano-tube arrays for fuel storage and power generation. The Aviation and Missile Research, Development, and Engineering Center (AMRDEC) is actively collaborating with academia, industry, and other Government agencies to accelerate the development and transition of nanotechnology to favorably impact Army Transformation. Currently, we are identifying near-term applications and quantifying requirements for nanotechnology use in Army missile systems, as well as monitoring and screening research and developmental efforts in the industrial community for military applications. Combining MicroElectroMechanical Systems (MEMS) and nanotechnology is the next step toward providing technical solutions for the Army’s transformation. Several research and development projects that are currently underway at AMRDEC in this technology area are discussed. A top-level roadmap of MEMS/nanotechnology development projects for aviation and missile applications is presented at the end.
Some Observations on Territoriality and Oviposition in Anax junius (Odonata: Aeshnidae)

The males of many odonate species show territoriality. According to Corbet et al. (1960), this aggressive behavior occurs above water and has the possible functions of: maintenance of food supply, initiation of dispersal, and prevention of interference with mating and oviposition. Johnson (1964) defines odonate territorial behavior as a species-specific interaction between males at the breeding site, especially noticeable when females are present. Sexually dimorphic color patterns common in odonate species function as sex recognition devices which initiate sex drive and aggressive behavior, while territoriality functions primarily to prevent over-competition for females at the breeding site (Johnson 1962).
Technical efficiency of Philippine agriculture

(1985). Technical efficiency of Philippine agriculture. Applied Economics: Vol. 17, No. 2, pp. 205-214.
A process approach to the implementation of new technology

Abstract This paper develops a process-oriented theoretical approach for understanding the implementation of new technology. Five processes - socialization, commitment, reward allocation, feedback and redesign, and diffusion - are conceptually related to the successful implementation of new technology. An approach for improving theoretical specification about implementing new technology is presented and illustrated with a case on vision systems technology.
Experience compiling Fortran to program dependence graphs

The program dependence graph (PDG) is being used in research projects for compilation to parallel architectures, program version integration and program semantics. This paper describes the methods used in a prototype Fortran-to-PDG translator called the PDG Testbed. Implementation decisions and details of the PDG Testbed project are described as a complement to the formal papers detailing the abstract PDG. In addition, experimental results are given that show the storage consumption for a PDG relative to a conventional internal representation as well as execution times for several analysis and optimization steps.
A Dimensional versus Attribute Approach For Disaggregate Choice Models

A fundamental issue facing choice modelers is to make a decision on what kind of independent variables to include in a choice model. With survey data, the two immediate options are: actual product attributes or underlying latent dimensions (factor scores). Using behavioral logic we argue that heterogeneity of consumer perceptions of variables and their saliences should be the key items moderating such a decision. We present empirical evidence to support our theory that dimensional (factor score) based models do better in terms of predictions than attribute based models in more heterogeneous populations. Empirical analysis shows that in segments (where consumer heterogeneity is lower) the predictive performance of attribute based models improves relative to the factor score model and may actually have a better predictive fit when the respondents are relatively homogeneous with respect to attribute ratings and saliences.
Growing up with The Calculus of Consent

It is fair to say that most of my academic life has been influenced by The Calculus of Consent: Logical Foundations of Constitutional Democracy (Buchanan and Tullock 1962) I was an undergraduate at Virginia Polytechnic Institute and State University (“Virginia Tech”) just after the Center for Study for Public Choice was founded there. I joined that university’s new graduate program in economics after a somewhat fortuitous contact with Charles Goetz, a founding member of the Center and former Buchanan student. The graduate courses were taught for the most part by scholars hired after the Center was up and running. I wrote my dissertation under James Buchanan’s guidance and a significant strand of the dissertation was influenced by a more or less casual conversation with Gordon Tullock while driving to a conference in Northern Virginia. In the late 1980s, after a decade of teaching at small private liberal arts, business, and engineering schools, I became a faculty member at the Center, shortly after it moved to George Mason University. The Calculus also clearly was very important to the careers of Buchanan and Tullock. Without that book, the names “Buchanan and Tullock” would not be closely linked in the minds of public choice or other scholars. Without the success of that book, it is likely that neither of these fine scholars would have had such a profound impact on economics and political science. This is not to say that they would not have been acknowledged as significant scholars without The Calculus, but it is to say that the success of that book lifted both men to a new level of prominence and placed them at the head of a two extremely fertile fields of research that grew rapidly for several decades. The new fields of inquiry came to be known as public choice and constitutional political economy. Without The Calculus, it is quite possible that the Public Choice Society would not have been founded, nor the Center for Study of Public Choice at Blacksburg. And it is doubtful