cssi/SciSciGPT-SciSciNet huggingface dataset:
Laparoscopic Removal of Common Duct Stones

Transcystic duct choledochoscopy is a safe and effective modality for clearing the common bile duct of stones encountered during laparoscopic cholecystectomy. The authors present early clinical experience with this new technique as developed at Cedars-Sinai Medical Center in Los Angeles.
Enhanced optical absorption in ultrathin silicon films using embedded silica-coated silver nanoparticles

Abstract Silver nanospheres with silica shells (Ag@SiO2) embedded into the absorber layer are explored as a plasmonic optical absorption enhancement method for thin-film photovoltaic cells. We observe dramatically enhanced absorption of the solar spectrum into a semiconductor medium by embedding a single monolayer of Ag@SiO2 nanoparticles in the central region of ultrathin mixed-phase amorphous/microcrystalline silicon (a/ μ c-Si) films. Optical absorption measurements indicate that integration of Ag@SiO2 nanoparticles increased absorption in the 400–1100 nm portion of the solar spectrum by 26% and 88% for 290 nm and 100 nm thick a/ μ c-Si thin films, respectively, in comparison to control films without any nanoparticles. This enhancement is concentrated in the longer wavelength range where the photon energy to bandgap ratio is higher, potentially yielding even larger increases in net device efficiency. Taking into account the interference of light within thin films, we show that parasitic losses due to particle absorption are minimal, consisting
Improving Pregnancy Outcomes with One-Carbon Metabolic Nutrients

Folate, vitamin B12, vitamin B6, and choline—collectively known as one-carbon or methyl nutrients—are involved in many biological processes vital to development, including nucleotide synthesis, methylation reactions, neurotransmitter production, lipid production and transport, and amino acid metabolism. The demand for these nutrients is particularly high during pregnancy, when cells of the placenta and fetus are undergoing rapid division. As such, pregnant women need to consume more of these nutrients to meet their higher requirements. Vegetables, fruits, legumes, and grains are rich sources of folate and vitamin B6, whereas vitamin B12 and choline are found most abundantly in animal products. Fortified foods and prenatal supplements are also an important source of folate, vitamin B12, and B6 for pregnant women. Deficiency of these nutrients is suggested to contribute to preeclampsia, preterm birth, birth defects, fetal growth retardation, and other adverse pregnancy outcomes, some of which can significantly affect the long-term health of mothers and their children. Clinicians who work with women of reproductive age should understand the role of these nutrients in fetal development and promote their greater intake to optimize pregnancy outcomes.
Hybrid Control of Vibratory Networks with Semiresonant Latches

A Semiresonant Latch (SRL) is a simple switching device that has emerged independently in several disparate areas of vibration engineering. It has equivalent realizations in both electrical and mechanical systems, and constitutes an extremely energy-efficient technique for imposing feedback on vibratory networks. Due to their low power demands, SRLs are useful in applications where the availability of energy for control is limited. SRLs influence the dynamics of vibratory systems by forcing near-instantaneous polarity reversals in the dynamic states of the network with which the devices are colocated. Due to the fact that they exhibit controlled state jumps, SRL-controlled networks can be modeled as hybrid systems. In this paper, we draw commonality between a number of different technologies which can all be classified as SRLs, and establish a standard hybrid system-theoretic framework in which to appraoch all such control problems. Due to space limitations, the scope of this paper is limited primarily to mechanical realizations of SRLs, and to networks in which only one SRL is embedded. We then illustrate how the same, Single Degree-of-Freedom (SDOF) SRL-controlled system can be controlled to accomplish disturbance rejection, energy harvesting, and equilibrium adaptation objectives. For the first two objectives, we re-cast ad-hoc techniques currently used for SRL control, in the context of the hybrid system framework. The use of SRLs to achieve the third objective (equilibrium adaptation) appears to be novel.
Guest Exchange through Facilitated Transport in a Seemingly Impenetrable Hydrogen-Bonded Framework.

A new inclusion compound consisting of a guanidinium 1,3,5-tri(4-sulfophenyl)benzene (G3TSPHB) host framework containing isophorone guests that surround isolated and seemingly inaccessible pockets was amenable to guest exchange with hexafluorobenzene (HFB) through a single crystal–single crystal transformation (SCSCT). Single-crystal X-ray diffraction of intermediate transformation states, from the parent compound G3TSPHB·(isophorone)3.7·(methanol)5.4 to the final state G3TSPHB·(isophorone)3.1·(HFB)2·(methanol)2, indicated a crystal symmetry change from monoclinic to hexagonal prior to full incorporation of HFB. Optical microscopy during the SCSCT revealed the formation of lamellae, which expanded and then coalesced into a single crystal when the phase transformation was complete. In situ Raman microscopy revealed changes in the orientation of isophorone guests during the transformation that suggested a pathway for HFB entry into the host cavities. The SCSCT occurs more rapidly than expected on the basis ...
Adapting Meaningful Learning Strategies for an Introductory Laboratory Course: Using Thin-Layer Chromatography to Monitor Reaction Progress

Introductory-level laboratory courses provide students with hands-on experience using the discipline’s tools and theories. These courses often rely on recipe-based experiments due to the constraint...
Financial Adequacy Affects Changes in Temporal Focus and Goal Striving Strategies Throughout Life

Drawing from Resource Scarcity Theory (e.g., Shah, Mullainathan, & Shafir, 2012) and Motivational Theory of Life Span Development (e.g, Heckhausen, Wrosch, & Schulz, 2010), the purpose of this stud...
Unpacking the Influence of Informational, Organizational, and Structural Factors on the Longitudinal Change of the NPO Follower-Followee Network on Twitter

A growing body of research has treated interorganizational networks as dynamic systems of communication. However, most longitudinal network studies have confounded the processes of new tie formation and old tie maintenance, resulting in an incomplete understanding of the processes of network change. Based on the multitheoretical multilevel framework, this study examines how different factors shape new tie formation and existing tie maintenance of a follower-followee network among 184 environmental nonprofit organizations on Twitter from 2014 to 2017. Actor-oriented modeling results demonstrated that organizations were more likely to form new ties with other organizations that more actively tweeted, shared similar organizational age and geographic location, and were already popular in the network. However, tie maintenance only correlated with geographic location and popularity. Organizations were particularly likely to dissolve existing ties with organizations of the same age. This study advances research on interorganizational communication, social networks, collective action, and networked relationship management.
Invertibility of switched linear systems

We address the invertibility problem for switched systems, which is the problem of recovering the switching signal and the input uniquely given an output and an initial state. In the context of hybrid systems, this corresponds to recovering the discrete state and the input from partial measurements of the continuous state. In solving the invertibility problem, we introduce the concept of singular pairs for two systems. We give a necessary and sufficient condition for a switched system to be invertible, which says that the individual subsystems should be invertible and there should be no singular pairs. When the individual subsystems are invertible, we present an algorithm for finding switching signals and inputs that generate a given output in a finite interval when there is a finite number of such switching signals and inputs. Detailed examples are included.
Intergranular fracture in bicrystals

Abstract Fracture experiments, at elevated temperatures, were carried out on bicrystals of copper containing silica particles. Fracture in each instance was intergranular. In all cases except one, fracture was caused by cavitation. The cavities grew either by diffusional transport or by plastic flow. In the rate equation for time to fracture, diffusional growth led to a linear stress dependence and an activation energy equal to that for boundary self-diffusion. Growth by plastic flow was manifested by a non-linear stress dependence and a higher activation energy. In one instance, when fracture occurred in only a few seconds, grain boundary separation was caused by the incompatibility of matrix slip at the grain boundary. Data in the literature indicates that the diffusional mechanism for the growth of cavities is suppressed in polycrystals; an explanation for this anamolous behavior is given. It is postulated that diffusional growth of cavities is possible in polycrystals in a hydrostatic state of stress.
C0 Interior Penalty Methods

C 0 interior penalty methods are discontinuous Galerkin methods for fourth order problems. In this article we discuss various aspects of such methods including a priori error analysis, a posteriori error analysis and fast solution techniques.
Identifying the Implementation Conditions Associated With Positive Outcomes in a Successful Nursing Facility Demonstration Project.

BACKGROUND AND OBJECTIVES To identify the implementation barriers, facilitators, and conditions associated with successful outcomes from a clinical demonstration project to reduce potentially avoidable hospitalizations of long-stay nursing facility residents in 19 Indiana nursing homes. RESEARCH DESIGN AND METHODS Optimizing Patient Transfers, Impacting Medical quality, Improving Symptoms-Transforming Institutional Care (OPTIMISTIC) is a multicomponent intervention that includes enhanced geriatric care, transition support, and palliative care. The configurational analysis was used to analyze descriptive and quantitative data collected during the project. The primary outcome was reductions in hospitalizations per 1,000 eligible resident days. RESULTS Analysis of barriers, facilitators, and conditions for success yielded a model with 2 solution pathways associated with a 10% reduction in potentially avoidable hospitalizations per 1,000 resident days: (a) lower baseline hospitalization rates and investment of senior management; or (b) turnover by the director of nursing during the observation period. Conditions for success were similar for a 20% reduction, with the addition of increased resident acuity. DISCUSSION AND IMPLICATIONS Key conditions for successful implementation of the OPTIMISTIC intervention include strong investment by senior leadership and an environment in which baseline hospitalization rates leave ample room for improvement. Turnover in the position of director of nursing also linked to successful implementation; this switch in leadership may represent an opportunity for culture change by bringing in new perspectives and viewpoints. These findings help define the conditions for the successful implementation of the OPTIMISTIC model and have implications for the successful implementation of interventions in the nursing facility more generally.
Teaching to Catholic Mission in Professional Education: A Comprehensive Model for the Integration of Catholic Social Teaching

Professional education programs have the dual challenge of fulfi lling the mission of two entities: their sponsoring institution and their profession. This may appear to be an inconvenient and even daunting burden. But, upon consideration, it becomes evident that the two missions are compatible and present rich and strategic opportunities to enhance the other. This article describes how one school of professional education creatively met this dual call to mission to pursue excellence in its educational program. Through a comprehensive model using the rich resource of Catholic Social Teaching, this school discovered new ways to enrich and distinguish how it educates and prepares a cadre of professionals to serve and lead in their profession and their community. The model, focused on social justice, holistically addresses faculty development, curriculum development, and student engagement. This case study presents rationale, strategies, and outcomes to inform and inspire other Catholic-sponsored professional education programs.
Ecological uncertainty favours the diversification of host use in avian brood parasites.

Adaptive responses to ecological uncertainty may affect the dynamics of interspecific interactions and shape the course of evolution within symbioses. Obligate avian brood parasites provide a particularly tractable system for understanding how uncertainty, driven by environmental variability and symbiont phenology, influences the evolution of species interactions. Here, we use phylogenetically-informed analyses and a comprehensive dataset on the behaviour and geographic distribution of obligate avian brood parasites and their hosts to demonstrate that increasing uncertainty in thermoregulation and parental investment of parasitic young are positively associated with host richness and diversity. Our findings are consistent with the theoretical expectation that ecological risks and environmental unpredictability should favour the evolution of bet-hedging. Additionally, these highly consistent patterns highlight the important role that ecological uncertainty is likely to play in shaping the evolution of specialisation and generalism in complex interspecific relationships. Nearly 17% of all bird species are hosts to obligate brood parasites like the common cuckoo. Antonson et al. show that parasite species hedge their reproductive bets by outsourcing parental care to a greater variety of host species when the rearing environment for their young is more unpredictable.
Evaluating the relationships between specific drainage area characteristics and soil metal concentrations in long-established bioswales receiving suburban stormwater runoff.

Bioswales are used to attenuate stormwater pollution, but their long-term sustainability regarding sequestered metals is relatively unknown, and a clear rationale for prioritizing soil management is lacking. Impervious areas draining into four 14-year-old suburban bioswales were delineated, for which surface soils (top 10 cm; 72 samples) were sampled; soils from 4 adjacent reference sites were also sampled. Total and water soluble metals (Cd, Cu, Pb, Zn) were quantified, and the relationships between metal concentrations and drainage area characteristics evaluated. Annual metal loads were estimated using regional runoff data to simulate current and future metal concentrations; risks to soil biota were assessed by comparing metal concentrations to ecological screening levels. The drainage areas' percent imperviousness (37-71%) and ratios of impervious drainage area to bioswale area (2.0-5.7) varied, owing to differing proportions of rooftops, paved surfaces, lawns, and natural soils. Total Cu and Zn ranged from 10.0 to 43.2 mg/kg dry soil, and 15.6 to 129.5 mg/kg dry soil, respectively. Across all bioswales, total Zn was positively correlated to percent impervious area (r = 0.32, p = 0.0073), the ratio of connected impervious drainage area to infiltration area (r = 0.32, p = 0.0073), and percent drainage area as paved surfaces (r = 0.46, p = 5.6 E-05), but negatively correlated to percent drainage area as lawns (r = -0.48; p = 2.4 E-05). Water soluble metal concentrations were orders of magnitude lower than total metals. Given annual metal loads (0.2-0.4 mg Cu/kg dry soil; 1.5-3.1 mg Zn/kg dry soil), replacing bioswale soils to constrain metal concentrations would be unnecessary for decades. Taken together, this study proposes a transferable approach of estimating, then verifying via sampling and analysis, bioswale soil metal concentrations, such that soil management decisions can be benchmarked to ecological screening levels.
Concordance probability as a meaningful contrast across disparate survival times.

The performance of time-to-event models is frequently assessed in part by estimating the concordance probability, which evaluates the probabilistic pairwise ordering of the model-based risk scores ...
Emerging dominance of Paratrochammina simplissima (Cushman and McCulloch) in the northern Gulf of Mexico following hydrologic and geomorphic changes

Abstract Grand Bay estuary in coastal Mississippi and Alabama (USA) has undergone significant geomorphic changes over the last few centuries as a result of anthropogenic (bridge, road, and hardened shoreline construction) and climatic (extreme storm events) processes, which reduce freshwater input, sediment supply, and degrade barrier islands. To investigate how geomorphic changes may have altered the Grand Bay estuary, sediment push cores were collected for foraminiferal, sedimentological (organic matter content, grain-size distribution), and radiochemical (210Pb,137Cs, and 7Be) analyses. Clay normalized geochronologies were determined with a constant rate of supply model. Based on downcore age-depth relationships, select intervals were analyzed for foraminifera in order to assess alterations in the microfossil assemblage in Grand Bay estuary over the 20th Century. All estuarine samples were low diversity (species richness: 1–10; Fisher's alpha diversity: 0.14–1.75); two species, Ammotium salsum and Paratrochammina simplissima, dominated all downcore assemblages. Paratrochammina simplissima increased in abundance up-core from a minor subsidiary species (median = 4.7% at 19–20 cm) to dominant or co-dominant with A. salsum over the 20th and early 21st Centuries in six cores, comprising up to 60.7% of a single sample. The emerging dominance of P. simplissima since ~1950 along with the reduction of brackish-estuarine taxa and introduction of calcareous species signifies increased salinity and less marsh organic matter preserved in the sediments. While seasonal dissolution limits our ability to chronologically constrain the introduction of calcareous species, P. simplissima, a species not referenced in taxonomic data from the northern Gulf of Mexico until 2012, is well constrained, following its first occurrence in the 1930s.
Determining the yield stress of a Biopolymer-bound Soil Composite for extrusion-based 3D printing applications

Abstract Biopolymer-bound Soil Composite (BSC) is a novel class of construction materials with potential use in extraterrestrial infrastructure development and more sustainable construction on Earth. Little is known about the rheological properties of this new material and its suitability for extrusion-based 3D printing (E3DP). This paper presents methods for testing BSC yield stress and proposes hydrodynamic and frictional yield stress models for predicting the static and dynamic yield stress of BSC mixtures. Using experimental results, a soil volume fraction range for BSC is identified that may be suitable for E3DP based on extrudability and shape stability requirements.
CONCRETE SLAB PERFORMANCE ON EXPANSIVE SOILS

The paper presents results from observations of 69 residences and their foundation slabs which are razed for a highway expansion. All houses were constructed in accordance with FHA standards and varied in age from 5 yr to 15 yrs at the time of demolition. Over 60% of the structures and interior damage due to foundation movements. Ninety percent of the slabs had movement cracks. Differential slab movements correlated to superstructure distress. Concrete and construction quality, within the limits investigated, did not appear related to movements or superstructure behavior. /Author/
Treatment Decisions Based on Scalar and Functional Baseline Covariates

The amount and complexity of patient-level data being collected in randomized-controlled trials offer both opportunities and challenges for developing personalized rules for assigning treatment for a given disease or ailment. For example, trials examining treatments for major depressive disorder are not only collecting typical baseline data such as age, gender, or scores on various tests, but also data that measure the structure and function of the brain such as images from magnetic resonance imaging (MRI), functional MRI (fMRI), or electroencephalography (EEG). These latter types of data have an inherent structure and may be considered as functional data. We propose an approach that uses baseline covariates, both scalars and functions, to aid in the selection of an optimal treatment. In addition to providing information on which treatment should be selected for a new patient, the estimated regime has the potential to provide insight into the relationship between treatment response and the set of baseline covariates. Our approach can be viewed as an extension of "advantage learning" to include both scalar and functional covariates. We describe our method and how to implement it using existing software. Empirical performance of our method is evaluated with simulated data in a variety of settings and also applied to data arising from a study of patients with major depressive disorder from whom baseline scalar covariates as well as functional data from EEG are available.
Protein Structure Hierarchy

The complexity of protein structures requires a description of their structural components. This chapter describes the elements of protein secondary structure — regular local structural patterns — such as helices, sheets, turns, and loops. Helices and sheets tend to fall into specific regions in the {o, Ψ} space of the Ramachandran plot (see Figures 3.18 and 3.19). The corresponding width and shape of each region reflects the spread of that motif as found in proteins.
The Explicit Costs of Government Deposit Insurance

The Diamond–Dybvig model is often cited as a theoretical justification for government-provided deposit insurance. Guaranteeing bank deposits removes the temptation for individual depositors to run on the bank and thereby precludes the need to ever use the deposit insurance. Hence, deposit insurance provides a costless solution to the threat of bank runs. In practice, however, government-provided deposit insurance is not a costless solution as it is frequently invoked to cover the losses of failed banks. We maintain that potential alternatives to government deposit insurance should be compared to the current system rather than to a theoretically optimal system of insurance. Focusing on the FDIC, we consider the differences between deposit insurance in theory and practice, review how the explicit cost of providing deposit insurance has changed over time, and consider implicit costs from taxpayer backing and suboptimal assessment rates.
Integrated Service Process Adaptation

With more automation in inter-organizational supply chains and proliferation of Web services technology, the need for organizations to link their business services and processes is becoming increasingly important. Using adapters to reconcile incompatibilities between multiple interacting business processes is an efficient and low-cost way to enable automatic and friction-free supply chain collaboration in an IT-enabled environment. My dissertation proposes a new framework and novel techniques for integrated service process adaptation. For the control flow adaptation, we propose an algorithm based on Message Interaction Graph to create an optimal adapter. For message adaptation, we identify a set of extendible message adaptation patterns to solve typical message mismatches. In addition new message adapter can be generated on the fly so as to integrate control flow considerations into message adaptation. Finally we design another algorithm to integrate individual message adaptation patterns with control flow adapters to create a full adapter for multiple processes. We implement all these algorithms in a Java-based prototype system and show the advantages of our methods by performance experiment and case study.
Student performance studying ethics in the context of internet use

The effectiveness of teaching ethical analysis concurrently with Internet use and development was studied in a course designed to: heighten the awareness of ethical issues surrounding the use of the Internet; aid students in making ethical decisions about their own computer use; and improve the critical analysis skills of the Internet user. First-year undergraduates completing this course improved their performance on standardized tests in moral reasoning (DIT) and Internet skills (Tek.Xam). The methodology of this pilot study could be used to form a larger study to encourage broad use of such a model.
Development and Inequity: The Case of Tubuai, a Welfare Economy in Rural French Polynesia

Social scientists note that development encourages the growth of wealth differences and structured social inequality in peasant communities. Recognizing this, some have advocated welfare and equity-oriented development strategies. It is proposed that development on Tubuai, an island society dominated by a welfare economy, approximates such strategies and that this case can be examined to assess their value. The structure of household socioeconomic differentiation which has emerged in response to new economic opportunities is described. The paper then examines the impact of a new potato cash-cropping project, documenting the structure of differential participation and isolating household level factors which are strongly associated with variable levels of development participation. It is argued that although development strategies are welfare and equity-oriented, development does not have a broad base of participation among Tubuai families and that a small segment of the population is expanding cultivation ...
Robotic Tasks for Chemical, Biological, Radiological, Nuclear and Explosive Incident Response

Chemical, biological, radiological, nuclear and explosive (CBRNE) incident response varies dramatically based upon the hazardous material, the incident size and the response duration. Robots can facilitate response planning, maintaining situational awareness, removing responders from dangerous situations and allowing for immediate site feedback prior to human responder entry. This paper presents eight robotic tasks informed by a cognitive task analysis and an information flow analysis. These analyses were conducted in order to inform the design of a system of multiple robots and the associated human–robotic interfaces required to support the CBRNE response command hierarchy. The cognitive task analysis was conducted over 3 years, and incorporated direct CBRNE response personnel feedback and CBRNE incident exercise observations. This paper presents the identified tasks and how robots can augment the existing human-based CBRNE incident response by improving the provided information and the speed at which in...
On Pade-type model order reduction of J-Hermitian linear dynamical systems ⋆

A simple, yet powerful approach to model order reduction of large-scale linear dynamical systems is to employ projection onto block Krylov subspaces. The transfer functions of the resulting reduced-order models of such projection methods can be characterized as Pade-type approximants of the transfer function of the original large-scale system. If the original system exhibits certain symmetries, then the reduced-order models are considerably more accurate than the theory for general systems predicts. In this paper, the framework of J-Hermitian linear dynamical systems is used to establish a general result about this higher accuracy. In particular, it is shown that in the case of J-Hermitian linear dynamical systems, the reduced-order transfer functions match twice as many Taylor coefficients of the original transfer function as in the general case. An application to the SPRIM algorithm for order reduction of general RCL electrical networks is discussed.
The Demand for Money: A General-Equilibrium Inventory-Theoretic Approach

There are two schools of thought in monetary theory; according to one school, the rate of interest is determined by the supply and demand for money; according to the other, the rate of interest is determined in the market for loanable funds. The conventional wisdom says that there is no difference between the two. For the money market coupled with the commodities market is exactly the same system as the securities (loans) market coupled with the commodities market (by Walras' Law).3 But this ignores one anomaly of the securities market (which is one manifestation of an anomaly noticed in a different context by Bent Hansen)4 and which is a key structural element in all Keynesian models. An increase in the supply of bonds in the Keynesian model creates an equal and opposite desire on the part of individuals qua savers to trade money for bonds, while it leaves unchanged the willingness of individuals qua money holders to make such trades. A special decomposition of the securities market results (which will be explained more precisely in the next section); this decomposition gives a structure to Keynesian systems which denies the importance of financial flows-and also differentiates in a real sense the standard monetary theory from a theory of the supply and demand for loanable funds. In general, this decomposition will not exist in money markets and is only present in the traditional analysis because of highly special assumptions or, more likely, because of a misrepresentation of the nature of the demand for money. There is, it should be noted, a difference between monetary demand and the demand for the standard commodity. For it is not the case that an individual is unhappy if he does not hold a precise amount of money, which is the amount of money demanded; rather, each individual has some rule of behaviour which, in the long run, in conjunction with his pattern of monetary flows, determines the average amount of money which he will hold. Although other types of behaviour are certainly possible descriptions of reality, standard monetary theory has pictured money as an inventory and the rule of behaviour governing the quantity held as an S-s policy. The " demand for money " has been taken to be the long-run average quantity of money which people with such policies and given patterns of
The Arithmetic Theory of Loop Groups. II. The Hilbert-Modular Case

Abstract We construct fundamental domains for arithmetic subgroups of loop groups of Hilbert-modular type.
A Survey of One Class of 7-Jointed Serially Connected Robots: Type-Synthesis to Obtain Controllably Dexterous Workspace

Etude d'une classe de robots formes d'un mecanisme en serie a sept articulations. Synthese du type afin d'obtenir un espace de travail ou l'on puisse controler la dexterite
Analysis of In-Service Traffic Sign Retroreflectivity and Deterioration Rates in Texas

Roadway traffic signs are a fundamental medium for conveying critical information to the road user. In 2009, the Manual on Uniform Traffic Control Devices (MUTCD) set minimum retroreflectivity requirements for such signs. Developing sign management strategies on the basis of service life is one approach to achieving compliance with minimum MUTCD sign retroreflectivity requirements. Generating deterioration rates and prediction models from a sample of in-service sign measurements is one method for establishing expected service life. In 2009, researchers collected a sample of 859 ASTM D4956 Type III retroreflectivity signs in seven regions of Texas. The objective of this study was to assess the compliance of Type III signs throughout Texas and to generate useful data that would improve sign maintenance practices. The overall sign sample compliance rate was 99%. The observed likelihood of failure was 2% for signs that were between 10 and 12 years old and 8% for signs that were 12 to 15 years old. The linear ...
The Style and Substance of API Names

Naming is a non-optional and cross-cutting design decision in professional and end-user programming activities. From assembly language to Yahoo Pipes, names are utilized for labeling and differentiation. Yet, we know little about how these names are selected or how naming impacts use and other aspects of de-sign. My research goal is to develop a theory of application programming interface (API) naming that bridges both software engineering and human-computer interaction. Towards this end, I am studying people (perceptions), information (naming strategies in the wild), and technology (name analysis algorithms and lightweight interactions to support naming decisions).
Chronic neonatal nicotine upregulates heteromeric nicotinic acetylcholine receptor binding without change in subunit mRNA expression.

Abstract Smoking during pregnancy chronically exposes the fetus to nicotine resulting in long-term behavioral and cognitive deficits. Nicotine binds to neuronal nicotinic acetylcholine receptors (nAChRs), pentameric ligand-gated ion channels widely expressed in the nervous system. Chronic nicotine upregulates high-affinity nAChRs in animals and smokers. Here we determined if chronic nicotine treatment during a developmental period corresponding to the human third trimester regulates nAChR expression. Rat pups were intubated orally three times per day with or without nicotine (6 mg/kg/day) from postnatal day 1 to 8. Subunit mRNA expression was assessed by in situ hybridization. Expression of heteromeric and homomeric nAChR receptor was evaluated by autoradiography using 125 I-epibatidine and 125 I-αbungarotoxin, respectively. nAChR expression was analyzed in cortex, hippocampus, thalamus and medial habenula from autoradiograms using computer assisted image analysis. Nicotine induced significant upregulation of heteromeric but not homomeric nAChRs in hippocampus, cortex and thalamus without changes in subunit mRNA expression. No effect of chronic nicotine on receptor expression was detected in the medial habenula, suggesting that nicotine's effect was mainly on α4β2-type heteromeric nAChRs. The nicotine-induced upregulation was reversed after nicotine withdrawal. Receptor blockade by DHβE, an antagonist for heteromeric α4/β2 nAChRs, did not prevent upregulation but increased expression to a similar degree as nicotine. Combination of both drugs had a cumulative effect. Thus, although transient, intermittent nicotine exposure as seen in smoking mothers is sufficient to upregulate heteromeric nAChRs during a critical period of brain development and could contribute to the behavioral deficits found in children whose mother smoked.
Automatic blocking of QR and LU factorizations for locality

QR and LU factorizations for dense matrices are important linear algebra computations that are widely used in scientific applications. To efficiently perform these computations on modern computers, the factorization algorithms need to be blocked when operating on large matrices to effectively exploit the deep cache hierarchy prevalent in today's computer memory systems. Because both QR (based on Householder transformations) and LU factorization algorithms contain complex loop structures, few compilers can fully automate the blocking of these algorithms. Though linear algebra libraries such as LAPACK provides manually blocked implementations of these algorithms, by automatically generating blocked versions of the computations, more benefit can be gained such as automatic adaptation of different blocking strategies. This paper demonstrates how to apply an aggressive loop transformation technique, dependence hoisting, to produce efficient blockings for both QR and LU with partial pivoting. We present different blocking strategies that can be generated by our optimizer and compare the performance of auto-blocked versions with manually tuned versions in LAPACK, both using reference BLAS, ATLAS BLAS and native BLAS specially tuned for the underlying machine architectures.
Urban greenspace composition and landscape context influence natural enemy community composition and function

Conservation research has historically been aimed at preserving high value natural habitats, but urbanization and its associated impacts have prompted broader mandates that include the preservation and promotion of biodiversity in cities. Current efforts within urban landscapes aim to support biodiversity and diverse ecosystem services such as storm water management, sustainable food production, and toxin remediation. Arthropod natural enemies provide biocontrol services important for the ecosystem management of urban greenspaces. Establishing habitat for these and other beneficial arthropods is a growing area of urban conservation. Habitat design, resource inputs, management, and abiotic conditions shape the value of greenspace habitats for arthropods. In general, larger patches with diverse plant communities support a greater abundance and diversity of natural enemies and biocontrol services, yet opposing patterns or no effects have also been documented. The surrounding landscape is likely a contributor to this variation in natural enemy response to patch-scale habitat design and management. Looking across rural–urban landscape gradients, natural enemy communities shift toward dominance by habitat generalists and disturbance tolerant species in urban areas compared to rural or natural communities. These changes have been linked to variation in habitat fragmentation, plant productivity and management intensity. In landscape-scale studies focusing solely within cities, variables such as impervious surface area and greenspace connectivity affect the community assembly of natural enemies within a patch. Given these findings, a greater mechanistic understanding of how both the composition and spatial context of urban greenspaces influence natural enemy biodiversity–biocontrol relationships is needed to advance conservation planning and implementation.
Outcome of portal-systemic shunt surgery for portal hypertension associated with intrahepatic obstruction in patients with agnogenic myeloid metaplasia

Life-threatening portal hypertension (PHN) in patients with chronic myeloproliferative disorders may result from increased portal flow caused by marked splenomegaly or an increased resistance to portal flow from either a large vein thrombosis or an intrahepatic obstruction usually associated with agnogenic myeloid metaplasia (AMM). The former cause is correctable by splenectomy alone, whereas the latter requires portal-systemic shunt surgery. Few data exist regarding the outcome of portal-systemic shunt surgery in patients with AMM and intrahepatic obstruction. During the past 25 years, 13 patients with chronic myeloproliferative disorders underwent portal-systemic shunt surgery at our institution. The cause of PHN was intrahepatic obstruction in ten patients and hepatic vein thrombosis in three. Ten of the thirteen patients had AMM as initial diagnosis. Only one patient had intraoperative complications, and four patients had either sepsis or thrombosis during the postoperative period. Twelve patients survived the postoperative period and had a median postsurgical survival of 3 years (range, 0.25 to 19 years). The long-term complications of the operation were very few and included hepatic encephalopathy (one patient), portal vein thrombosis (one patient), and shunt occlusion (one patient). The procedure was successful in alleviating complications of PHN in all but one patient. Deterioration of hepatic function and subsequent hepatomegaly were unusual. Portal-systemic shunt surgery seems to be a useful option in patients with AMM and lifethreatening PHN from intrahepatic obstruction. © 1994 Wiley-Liss, Inc.
Temperature fields due to jet induced mixing in a typical OTV tank

The Eclipse Code is being developed as a general tool for analysis of cryogenic propellant behavior in spacecraft tankage. The focus of the work being reported is on prediction of temperature fields due to introduction of a cold jet along the centerline of a typical Orbit Transfer Vehicle tank. A brief description of the formulations used for modeling heat transfer and turbulent flow is presented. Code performance is verified through comparison to experimental data for mixing in small scale tanks. An unexpected difficulty in computing long duration flows is reviewed. Preliminary results for a partially filled full scale tank are obtained by approximating the free surface by a spherical solid boundary.
Building Supportive School Environments for Alternative Education Youth.

This article reports findings from a study of an alternative educational program for at-risk secondary students, comparing student perceptions of their public school environment, measured upon intake in the alternative school, with their perceptions of the alternative school environment after four and eight months of attendance in the program. Student perceptions of teacher support in the alternative school environment were significantly more positive than their perceptions of the public school environment. Another purpose was to assess the relation between student perceptions of various aspects of the school environment with specific academic, behavioral, and socioemotional variables. The implications of these findings and future research inquiries are addressed.
Increase in levels of cyclic AMP during avian limb chondrogenesis in vitro.

In the present study the level of cAMP was measured during in vitro chondrogenesis of wing mesenchyme of stage 24 chick embryos and was found to increase significantly from 6.3 pmol/mg protein at the end of the first day of culture to 9.7 pmol/mg protein on the second day, when chondrogenic expression is first detected by the appearance of an Alcian blue staining extracellular matrix. Nonchondrogenic cultures derived from wings of stage 19 embryos had a lower level of cAMP (4.4 ± 0.07 pmol/mg protein). The level of CAMP in intact wings was 4.5 ± 0.4 pmol/mg protein and did not change between stages 19 trough 25. The correlation between increased levels of CAMP and the onset of chondrogenesis is consistent with a role of cAMP in the expression of differentiated functions in chondrocytes, as well as in some other cell types.
Child care subsidies and child care choices: The moderating role of household structure

Abstract A recent but growing literature has explored the implications of federally-funded child care subsidies for child well-being. While subsidies have been shown to move children into child care settings of higher observed quality, and high quality care has been associated with improved school readiness, some evidence suggests that subsidy use is associated with neutral or negative child outcomes. These findings may be explained by patterns of care choice among subsidy receiving mothers. This study investigates whether household structure moderates the association between subsidy receipt and choice of child care arrangement using samples drawn from two demographically distinct data sources: the exclusively urban Fragile Families and Child Wellbeing Study (FFCWS) and the nationally representative Early Childhood Longitudinal Study—Birth Cohort (ECLS-B). Results indicate that household structure alters the association between subsidy use and care arrangement, but the moderating role of household structure differs across the two samples. In the FFCWS, living with extended family increased the likelihood that mothers use subsidies for informal family, friend, and neighbor (FFN) care rather than center based care; in the ECLS-B, living with extended family decreased the likelihood of mothers using subsidies for informal FFN care versus center-based care. Findings suggest that household structure is an important moderator of subsidy use, but that its impact may depend on contextual and demographic factors.
Expansion of classical differential cross sections in legendre polynomials: Nonreactive scattering

Abstract The expansion of classical, nonreactive differential cross sections in a series of Legendre polynomials is described. The series coefficients can be determined from the deflection angles computed in classical trajectory studies. In general, nonreactive systems require more trajectories as well as more terms in the series than do reactive systems. Model calculations presented here show that 20000 trajectories are sufficient to give an accurate description of the cross section. This is comparable to other methods for displaying nonreactive differential cross sections.
Micromanipulation of Cyanelles and a Cyanobacterium into Higher Plant Cells

A cyanobacterium (WPI-I) and cyanelles of Glaucocystis nostochinearum Itz, have been introduced into epidermal cells of Allium cepa L. cv. Downing Yellow Globe bulb scales by microinjection. Uptake of cyanelles into protoplasts of Allium cepa and Daucus carota L. cv. Imperator 58 has also been induced with polyethylene glycol. Protoplasts were cultured until new cell walls were synthesized.
Genetic variation in the oyster, Crassostrea virginica (Gmelin), in relation to environmental variation

Four polymorphic loci in seven natural oyster (Crassostrea virginica Gmelin) populations of the Chesapeake Bay were analyzed by protein-gel electrophoresis for genetic variation. Samples of about 100 each were taken in 1977 along environmental gradients from stations in the James and Potomac rivers. The distribution of genotypes at four loci for each of the stations was nog significantly different from Hardy-Weinberg expectations. At two loci (Pgi andLap-2), a pool of all seven stations was also in equilibrium. Significant genetic differentiation between rivers was detected for two other loci (Pgm-1 andLap-1), and frequency of one genotype (Lap-1 95/95) was significantly correlated with mean temperature over the water monitoring period (1972–1977).
K + scattering from nuclei

Abstract The present status of the K + -nuclear scattering problem is discussed, and implications of the new data sets involving K + total, elastic, and quasi-free cross sections are pointed out.
Three's company: an unusual clue.

D O ous p ugg urs w the n t and c ni and e with o ent w aus c c itive p ona has a s ade. H a or c of c diog right v pir and m mp ssoc dia ( limb l elect varia ed in c (2:1) p a P l RESENTATION his case illustrates how a unique ECG pattern provide nusual clue to the diagnosis in a febrile patient. The p as a 30-year-old African woman who presented to mergency department after suffering 7 days of intermit evers, night sweats, increasing shortness of breath, alaise. She had a sharp, nonradiating chest pain w ying supine, and when she swallowed, she experien onspecific chest discomfort that created a sensation ullness. She denied recent weight loss. Other than nfant daughter, who had had a runny nose 2 weeks e he reported no close sick contacts. The patient, who had immigrated to the United S rom Kenya 12 years previously, worked in homeless ers as a social worker. She had received the B almette Guerin vaccination as a child, and she de xposures to tuberculosis. She reported having a posi urified protein derivative (PPD) tuberculin test in the ut she had not completed treatment for latent tubercul er medications included omeprazole and acetaminoph therwise, her medical history was unremarkable.
Venous Insufficiency at Work

Chronic venous disease of the lower limbs is one of the most common conditions affecting humankind. It has been postulated that certain workplace conditions may be risk factors for venous insufficiency and varicose veins in particular. This paper examines the evidence for a link between occupation and the prevalence of venous disease. It also reviews recent French research carried out to estimate the prevalence of chronic venous insufficiency in a working population; work and nonwork risk factors and the cost to industry from this condition are also examined.