cssi/SciSciGPT-SciSciNet huggingface dataset:
Developing an Automatic System for Classifying Chatter About Health Services on Twitter: Case Study for Medicaid

Background: The wide adoption of social media in daily life renders it a rich and effective resource for conducting near real-time assessments of consumers’ perceptions of health services. However, its use in these assessments can be challenging because of the vast amount of data and the diversity of content in social media chatter. Objective: This study aims to develop and evaluate an automatic system involving natural language processing and machine learning to automatically characterize user-posted Twitter data about health services using Medicaid, the single largest source of health coverage in the United States, as an example. Methods: We collected data from Twitter in two ways: via the public streaming application programming interface using Medicaid-related keywords (Corpus 1) and by using the website’s search option for tweets mentioning agency-specific handles (Corpus 2). We manually labeled a sample of tweets in 5 predetermined categories or other and artificially increased the number of training posts from specific low-frequency categories. Using the manually labeled data, we trained and evaluated several supervised learning algorithms, including support vector machine, random forest (RF), naive Bayes, shallow neural network (NN), k-nearest neighbor, bidirectional long short-term memory, and bidirectional encoder representations from transformers (BERT). We then applied the best-performing classifier to the collected tweets for postclassification analyses to assess the utility of our methods. Results: We manually annotated 11,379 tweets (Corpus 1: 9179; Corpus 2: 2200) and used 7930 (69.7%) for training, 1449 (12.7%) for validation, and 2000 (17.6%) for testing. A classifier based on BERT obtained the highest accuracies (81.7%, Corpus 1; 80.7%, Corpus 2) and F1 scores on consumer feedback (0.58, Corpus 1; 0.90, Corpus 2), outperforming the second best classifiers in terms of accuracy (74.6%, RF on Corpus 1; 69.4%, RF on Corpus 2) and F1 score on consumer feedback (0.44, NN on Corpus 1; 0.82, RF on Corpus 2). Postclassification analyses revealed differing intercorpora distributions of tweet categories, with political (400778/628411, 63.78%) and consumer feedback (15073/27337, 55.14%) tweets being the most frequent for Corpus 1 and Corpus 2, respectively. Conclusions: The broad and variable content of Medicaid-related tweets necessitates automatic categorization to identify topic-relevant posts. Our proposed system presents a feasible solution for automatic categorization and can be deployed and generalized for health service programs other than Medicaid. Annotated data and methods are available for future studies. Trial Registration:
How Social Ties with Undocumented Immigrants Motivate Latinx Political Participation

Prior research suggests social ties with undocumented immigrants among Latinxs may increase political engagement despite constraints undocumented social networks may introduce. We build on prior re...
Exploring Amateur Performance in Athletic Tests Using Wearable Sensors

The growing market for sports analytics has spurred more interest than ever in quantifying athletic performance. This trend, alongside the proliferation of new wearable technologies, has expanded the possibilities for both professional and amateur athletes to instrument themselves and collect meaningful data. The reactive strength index (RSI) can be used to communicate this kind of data by presenting a person’s ability for rapid movement. A user study was conducted in which young adults of amateur athletic status performed a jumping exercise to assess the feasibility of using a commercial off-the-shelf inertial measurement unit (IMU) to measure this metric compared to the usual method of using a force plate. Results suggest that the measurement of meaningful RSI improvements is possible using inexpensive IMUs with comparable results to costly force plates.
The Explanatory Generalized Graded Unfolding Model: Incorporating Collateral Information to Improve the Latent Trait Estimation Accuracy:

Collateral information has been used to address subpopulation heterogeneity and increase estimation accuracy in some large-scale cognitive assessments. The methodology that takes collateral informa...
Orthostatic Headaches Associated With Spontaneous Intracranial Hypotension and Autonomic Dysfunction-A Case Series in Young Patients

Background: Orthostatic headaches can be noted in spontaneous intracranial hypotension and orthostatic intolerance. We present a case series of young patients diagnosed with spontaneous intracranial hypotension and were treated for the same but subsequently developed orthostatic intolerance. Methods: We retrospectively reviewed charts for seven young patients with orthostatic headaches related to spontaneous intracranial hypotension and orthostatic intolerance. Results: Patients were diagnosed with spontaneous intracranial hypotension. Diagnosis was confirmed by identifying epidural contrast leakage and three of seven patients were noted to have early renal contrast excretion on computerized tomography myelography. Patients were treated with epidural blood patches. All patients showed persistent symptoms of autonomic dysfunction after treatment of spontaneous intracranial hypotension and orthostatic intolerance was confirmed with head-up tilt table test. Conclusions: Patients with spontaneous intracranial hypotension failing to improve following epidural blood patching should be evaluated for orthostatic intolerance.
Rubella in the distant past as a possible cause of congenital malformations

Abstract Four cases of congenitally malformed infants whose mothers had rubella within 2 years preceding, but not during, the period of their gestation have come to our attention. Rubella had occurred in 3 of the mothers during a former pregnancy. This report provides evidence that these malformations were not the consequence of an intrauterine infection of the fetus with rubella virus. A survey of other mothers who had given birth to rubella syndrome children demonstrated a small but probably insignificant increase in fetal abnormality in subsequent births.
Dizziness and panic in China: associated sensations of zang fu organ disequilibrium.

In China, distress is commonlyexperienced as dizziness that can develop intoacute episodes resembling Western panicattacks. These distressing sensations occur ina unique cultural context with a distinctiveset of associated symptoms, beliefs andpurported etiologies. The experience ofillness is informed by traditional Chinesemedicine (TCM), an indigenous theory thatelaborates a system of organ functioning calledzang fu. Depending on the implicatedzang fu organ disequilibrium, dizzinessand panic present with a specific constellationof associated physical and mental symptoms. This paper presents a clinical survey ofpsychiatric disorders that demonstratesdizziness to be characteristic of Chineseanxiety states, most particularly panic. Threespecific cases of dizziness-focused panicascribed to different states of zang fudisequilibrium are described. In a typicalpattern, initial dizziness and associatedsymptoms intensify until they generalize intopanic attacks. The degree of dizziness andpanic corresponds to the state ofdisequilibrium of the zang fu organsystem as well as instability of the social,interpersonal and environmental context of thepatient. This paper elucidates the dynamicinterpretants of dizziness in the Chinesecontext to contribute to a medical anthropologyof this sensation.
Efficient and final causes of alcohol consumption.

Keywords: Alcohol demand; alcohol purchase task; behavioral economics; delay discounting; molar analysis; teleological behaviorism
Severe eating disorder initially diagnosed in a 72-year-old man.

Objective: Eating disorders in our society mainly affect young women. Cases in males are far less common, and reported cases in elderly males are rare. Method: We report the case of 72-year- old male admitted to a geriatric psychiatry service for grave passive neglect with mild dementia thought to be due to nutritional deficiency. Results: The patient was found to have an eating disorder not otherwise specified, most closely resembling anorexia nervosa, which was believed to be the cause of the nutritional problem. Conclusion: This case highlights the need for diagnostic awareness regarding eating disorders in patients of all ages and of both genders. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2008
Effects of Boundary Films on the Frictional Behavior of Rough-Surface Contacts in Incipient Sliding

Research has shown that the interfacial shear strength in an asperity contact is generally a linear function of the asperity pressure with a maximum value below the shear strength of the substrate material. Research further suggests that the properties of the surface-film materials in the micro-contact largely govern the shear-strength-pressure relation and the maximum attainable interfacial shear strength. This paper studies the effect of boundary films on the frictional behavior of rough-surface contacts in incipient sliding. Two parameters are used to describe the shearing properties of the boundary film. One is the shear-strength-pressure proportionality constant and the other, the ratio of the maximum interfacial shear strength to the substrate shear strength. The study uses an asperity-based mathematical model for frictional sliding-contact of nominally flat elastic-plastic rough surfaces incorporating the above interfacial shearing properties in the asperity contacts. A sequence of parametric studies is carried out to study the frictional behavior of the contact system. The parameters include surface plasticity index, contact load, and boundary film properties. More details of the results along with literature studies and references are presented in a full paper [1].Copyright © 2005 by ASME
DNA Replication Efficiency Depends on Transcription Factor-Binding Sites

Naturally arising variants of simian virus 40 (SV40), generated by serial passage of the virus at high multiplicities of infection, provide important insight into the role of transcription factor-binding sites in enhancing DNA replication. Although the variants that arise from numerous recombination events are the result of selective pressure to replicate more efficiently than the other variants in the infection, there is no transcription pressure. Therefore, it is interesting that a minimum of two viral Sp1 transcription factor-binding sites are retained and that host AP-1 and NF-1 transcription factor-binding sites are incorporated into the 100-bp regulatory region that maximizes DNA replication in these variants. We cotransfected COS-1 cells (that provide viral large T antigen for DNA replication) to examine the effect of transcription factor-binding sites on the replication of plasmid constructs that contain the SV40 origin of replication ( ori ). The level of relative replication efficiency (RRE) depends on the number and type of transcription factor-binding sites. Replication increases as the number of transcription factor-binding sites increases within the regulatory region of the variants; AP-1 sites are more effective than NF-1 transcription factor-binding sites. Competition between constructs in transfections magnifies the difference in their RREs. The results indicate that transcription factor-binding sites play an important role in enhancing DNA replication.
Political Exclusion and the Lack of Democratisation: Cross-National Evaluation of Nepali Institutions using a Majoritarian–Consensus Framework

Abstract Going beyond examining single institutions, which is not sufficient to establish a polity's effect on exclusion, the article adapts Lijphart's majoritarian–consensus framework, which analyses ten influential institutions, to evaluate the Nepali polity. The cross-national evaluation shows that the Nepali institutions are not inclusive. As some individual Nepali institutions are exclusionary, combining individual and collective analysis establishes the net effect of political institutions as exclusionary. This study demonstrates that collective political institutions in new multicultural democracies can be evaluated in terms of inclusion/exclusion. Such evaluations are useful in providing the basis for reforming polities to include minorities and consolidate and deepen democracy.
Periodic divisible-by-finite automorphism groups are finite

In [9], D. J. S. Robinson showed that Aut G, the group of automorphisms of a group G, cannot be an infinite Cernikov group. A natural question therefore arises as to whether Aut G can ever be an infinite, periodic divisible-by-finite group. Here, and throughout this paper, we shall call a (multiplicative) group A divisible, if A is abelian and every element of A has an n th root for every natural number n. It is shown in [2] that some infinite divisible groups occur as automorphism groups of abelian groups and further examples of divisibleby-finite automorphism groups are given in this paper. However, our main result establishes the following generalization of [9, Theorem A]:
Productivity and Reproductivity: Fertility and Professional Achievement among Research Scientists

Data for a group of research chemists are examined to test the hypothesis that marital fertility is associated with lower levels of research productivity and to assess the extent to which the fertility-productivity relationship varies by sex. The results show a negative relationship between fertility and productivity among the scientists; the relationships for the sexes are similar in direction and magnitude. We argue that previous studies of the impact of marital fertility on career attainments have failed to find the expected negative association because they have dealt with workers who cannot freely invest extra time and energy in work efforts and because they have used inadequate measures of attainment such as occupational mobility rather than more direct measures of job performance. The idea that occupational success is negatively associated with fertility is a classical hypothesis in social demography. Ambition for social achievement, it is reasoned, motivates couples to limit the number of their children in order to free the time, energy, and money which are usually required to rear a large family, for economic and occupational pursuits (Berant; Westoff et al.). Investing these resources in occupational activities should result in superior economic or occupational performance, which should in turn be reflected by later career success. The hypothesized negative association between career success and fertility should be due in part to deliberate attempts by ambitious couples to limit their fertility and in part to the advantages which extra resources confer on couples who have fewer children, regardless of the reasons for their lower fertility. *We are grateful to Paul D. Allison and Paula M. Hudis for their comments on a previous draft of this paper.
Task Equivalence and a Failure to Detect Interference Effects among the Logical Memory Stories of the Wechsler Memory Scale—Revised

66 healthy young adults, matched on age, sex, and education, were administered the Logical Memory passages of the Wechsler Memory Scale—Revised in standard order (A + B) or reverse order (B + A). Recall of both stories was similar regardless of the order of administration, suggesting that the stories were equivalent in task difficulty. Despite equivalence of story difficulty, proactive interference was not observed in this sample. These results are discussed within the context of previous research, and suggestions for further research are made.
The Trouble with Triples: Elucidating the Behavior of Trinucleotide Repeats in Chromatin

Trinucleotide repeats (TNRs) occur throughout the genome and their expansion can affect varied cellular processes such as gene expression, mRNA processing, and protein folding. TNR expansion, facilitated by formation of stable non-canonical secondary structures (e.g. hairpins), has been linked to several neurodegenerative diseases, such as Huntington's Disease, Myotonic Dystrophy (both caused by expansion of CAG•CTG repeats), and Fragile X Mental Retardation (caused by expansion of CGG•CCG repeats). TNR structure and expansion has been studied in vitro using both oligonucleotides and TNRs incorporated into plasmids; however, genomic DNA is packaged into chromatin, and little is know about the effect of packaging on the ability of repetitive DNA to expand. Previous studies have shown that disease-length, expanded CAG•CTG repeats readily incorporate into the basic unit of chromatin packing, the nucleosome core particle (NCP), composed of 146 base pairs of DNA wrapped around a core of eight histone proteins. However, long CGG•CCG repeats exclude NCP formation. Here, we seek to investigate not only the properties associated with shorter repeats (those that have not expanded) incorporated into NCPs, but also the effect of the flanking, disease-associated gene sequence. To assess the global forces regulating interaction between the TNRs and the histone core, we performed competitive nucleosome exchanges to determine the efficiency with which various TNR sequences incorporate into NCPs. We then used enzymatic and chemical probing to determine the effect of histone occupancy on the TNRs, including the formation of possible non-canonical structures. Understanding the intricacies underlying the interaction between unexpanded TNRs and the histone core is important to understanding how TNRs expand in the genome.
Microlithon alteration associated with development of solution cleavage in argillaceous limestone: textural, trace-elemental and stable-isotopic observations

Abstract Comparison of microlithons (the rock between adjacent cleavage domains) in strongly cleaved argillaceous limestone with samples of uncleaved limestone from the same stratigraphic horizon (Lower Devonian Kalkberg Formation, Hudson Valley of eastern New York) indicates that the process of cleavage formation results in significant changes in microlithon fabric and in the chemistry of microlithon calcite. Petrographic observation indicates that at least 50% of the calcite in microlithons is recrystallized as calcite fibers whose long axes are subparallel to cleavage domains. The fibrous calcite occurs as overgrowths on larger grains, in thin bed-parallel veins, and in ‘diffuse extension zones’ (areas of the microlithons in which inequant crystals of microcrystalline calcite are aligned parallel to cleavage domains). Chemical analyses show that calcite in microlithons of strongly cleaved limestone is enriched in Mn and Sr relative to calcite in uncleaved limestone. δ 18 O and possibly δ 13 C values for calcite in strongly cleaved rock are significantly smaller than values for calcite in uncleaved rock. These results indicate that microlithon calcite is completely recrystallized (i.e. much more calcite is recrystallized than is visible in thin section) and that it underwent exchange with a fluid external to the local rock system. Calculation of the water/rock ratio suggests that 0.1–2.6 volumes of water may have exchanged with the calcite during cleavage formation. Comparison of the minimum integrated and the inferred instantaneous water/rock ratios suggests that bulk fluid flow occurred during microlithon recrystallization. Comparison of the amount of shortening across cleavage domains with the amount of extension in microlithons, and of the volume of calcite dissolved in domains with the amount of fibrous (presumably added) calcite in microlithons, suggests that microlithons are a major sink for the calcite dissolved in domains during cleavage formation, and that at this locality, development of disjunctive solution cleavage in the Kalkberg Formation resulted in volume-constant plane strain.
Modeled interactions of mesoscale eddies with the East Pacific Rise: Implications for larval dispersal

Larval transport from distant populations is essential for maintenance and renewal of populations in patchy and disturbed ecosystems such as deep-sea hydrothermal vents. We use quasi-geostrophic modeling to consider the potential for long-distance dispersal of hydrothermal vent larvae in mesoscale eddies interacting with the northern East Pacific Rise. Modeled eddy dynamics were similar to the observed propagation dynamics of Tehuantepec eddies, including their ability to cross the ridge. Simulated surface anticyclones were associated with coherent cyclones in the deep layer with relatively strong current velocities that could significantly increase the dispersal potential of passive particles. Eddy interactions with ridge topography further enhanced tracer dispersal along the ridge axis through shearing and elongation of the eddy core. Simulations suggest that the passage of an eddy would result in local loss from the vent field and aggregate transport with potential enhancement of dispersal between vent fields separated by up to 270 km. Based on the latitude at which most Tehuantepec eddies cross the ridge, eddy-induced flows would enhance connectivity between the 13°N, 11°N, and 9°N vent fields along the East Pacific Rise asymmetrically with higher transport from northern vent fields to southern vent fields.
Phototransistor-based optoelectronic tweezers for dynamic cell manipulation in cell culture media

Optoelectronic tweezers (OET), based on light-induced dielectrophoresis, has been shown as a versatile tool for parallel manipulation of micro-particles and cells (P. Y. Chiou, A. T. Ohta and M. C. Wu, Nature, 2005, 436, 370–372).1 However, the conventional OET device cannot operate in cell culture media or other high-conductivity physiological buffers due to the limited photoconductivity of amorphous silicon. In this paper, we report a new phototransistor-based OET (Ph-OET). Consisting of single-crystalline bipolar junction transistors, the Ph-OET has more than 500× higher photoconductivity than amorphous silicon. Efficient cell trapping of live HeLa and Jurkat cells in Phosphate Buffered Saline (PBS) and Dulbecco's Modified Eagle's Medium (DMEM) has been demonstrated using a digital light projector, with a cell transport speed of 33 µm/sec, indicating a force of 14.5 pN. Optical concentration of cells and real-time control of individually addressable cell arrays have also been realized. Precise control of separation between two cells has also been demonstrated. We envision a new platform for single cell studies using Ph-OET.
Evaluations of Consumers’ Preference Structure for Locally-Produced Beef

This study assesses how locality of production, method of production, and price of beef and beef products influence purchasing preferences. Consumers were surveyed for demographic, economic, and taste and preference characteristics. A conjoint analysis is implemented to analyze the effect of various product attributes on consumers’ beef purchases. The results reveal that the most important of the attributes for consumers is the distance of origin. Consumers consider beef locally grown if the beef is produced within an 85-mile radius, and the distance of origin accounts for 60% of the total importance from all attributes.
Evolution of photo-stimulated luminescence of EB-PVD/(Ni, Pt)Al thermal barrier coatings

Abstract Experiments are described which were designed to assess the suitability of photo-stimulated luminescence piezo-spectroscopy (PLPS) measurements as a basis for non-destructive inspection (NDI) and determination of life remaining of thermal barrier coatings (TBCs). Thermal cyclic tests were conducted on 7 wt.% Y 2 O 3 stabilized ZrO 2 (YSZ) electron beam physical vapor deposited (EB-PVD)/(Ni, Pt)Al/CMSX-4 TBCs at two temperatures 1151 and 1121 °C. The evolution of PLPS spectral characteristics (peak frequency shift, peak width and area ratio of peaks) was studied as a function of thermal cycles. It was observed that the average thermally grown oxide (TGO) stress and its standard deviation, and the area ratio of peaks show systematic change with thermal cycling, indicating that these characteristics can be used for NDI and determination of life remaining. The average TGO stress increases initially and then decreases monotonically with thermal cycling. The rate of change in the stress can be related to specimen life: the shallower the slope, the higher the life. The peak area ratio also decreases monotonically with cycling. The average TGO stress changes in a systematic manner versus remaining life fraction independent of temperature. Remaining life predictions were made based on average stress versus life fraction, which resulted in life assessments within ±13% of actual values excluding one specimen with abnormal behavior.
Complex sexual courtship displays by luminescent male marine ostracods

In the western Caribbean Sea, about an hour after the sun sets, a complex and ritualized light show of precise, vertically placed luminescent pulses erupts over shallow grassbeds. These are among the most complex displays known in marine systems. Displays consist of repeated trains of secreted bioluminescent pulses in a specific pattern ejected into the water column as courtship signals by male Vargula annecohenae, which are small (<2 mm) myodocopid ostracod crustaceans. Although these animals display in near darkness, we have used image intensification and infrared videography and three-dimensional analysis in the lab to demonstrate that each luminescent display train, which can be up to 60 cm long, consists of two distinct luminescent and swimming phases. The first, or 'stationary,' phase consists of three (usually) bright, longer pulses placed close together, with the male swimming in a looping pattern. We hypothesize that this pattern acts as an attention-grabbing signal for receptive females. The stationary phase is followed by the 'helical phase,' which consists of about a dozen evenly placed dimmer, shorter pulses secreted by an individual male rapidly spiraling upward in a helical pattern. We hypothesize that this phase, which has very uniform interpulse intervals and distances, helps an approaching female target and intercept the rapidly moving male. Here we provide details of these two phases, and produce a three-dimensional model of a multiply-displaying male.
Temporal Horizons and Presidential Election Forecasts

In this article we present a simple forecasting model that has been successful at predicting past presidential elections. The two variables included in the model are cumulative per capita income growth and presidential approval. These "fundamental" variables predict the vote especially well when measured shortly in advance of the election, when the outcome is already becoming clear in the polls. Their predictive power drops quite quickly as one steps back from the election, however; readings of income growth and approval taken early in the election year only modestly predict readings of the same variables just prior to the election. Thus we turn to leading economic indicators that allow us to forecast presidential elections by giving advance indication of changes in the economy and approval during the election year. For 1996, our model offers a cautious prediction of a Clinton victory.
Effect of backleak in nephron dynamics

The effect of transepithelial solute, i.e., sodium chloride, backleak is taken into consideration in the spatiotemporal evolution of the chloride concentration along the thick ascending limb of a single nephron. The importance of the mechanism and of its mathematical modeling is argued on physiological grounds. The backleak "strength" is found to significantly modify the threshold for the appearance of temporally oscillatory behavior in the chloride concentration in the thick ascending limb which has previously been experimentally observed in normotensive rats.
968-26 In Vitro Antiproliferative Effect of Antisense Oligonucleotides: Are the Effects Specific and Reproducible?

The involvement of proto-oncogenes in cell proliferation is well documented. One of these, the oncogene c-myb is a DNA-binding protein that regulates cell growth and differentiation. In-vitro studies have shown marked inhibition of smooth muscle cell (SMC) proliferation using antisense (AS) c-myb oligonucleotides. The purpose of this study was to determine whether the in-vitro anti proliferative effect of AS oligonucleotides is specific and reproducible. Rat aortic SMC were plated at a 1:3 split ratio in 1% fetal bovine serum (FBS), and made quiescent 24 hr later by changing the medium to 1% control process serum replacement II. Cells were stimulated with PDGF (2 ng/ml), and at the same time, oligonucleotides were added. Cell proliferation was determined by measuring 3 H-Thymidine uptake at 18–22 hr. To compare the specificity of the antiproliferative effects. 20 μM of AS c-myb and several control oligos were used. These included (Batch A): 18-mer sense (5) c-myb. 19-mer mouse antisense and four-base mismatch AS to IL-lβ, and 18- and 16-mer human AS to CML. To determine the reproducibility of the AS effect, the same 18-mer AS c-myb and scrambled (Sc) lS-mer from another source (B) were used under exactly the same conditions. To further evaluate the reproducibility of the AS effect, two different preparations (Batch C) of the same 18-mer AS and S c-myb from the initial manufacturer were tested under exactly the same culture conditions. Conclusions This study shows: 1) that antisense oligonucleotides produce a non-specific in-vitro antiproliferative effect and 2) the in-vitro results may vary with respect to source and batches of oligonucleotides. The lack of consistency in results raises significant questions about clinical therapeutic potential.
System integration for image production and real-time control

An approach to integration of software and hardware for image production closely coupled with real-time control of an instrument is described. Image production includes reconstruction, processing, display, archiving and export. Feedback of information from images to instrument control is an essential feature, often with a human operator in the loop. Real-time control requires guaranteed response to external events, support for multiple processors and a variety of interfaces to instrumentation. Image production involves implementation of reconstruction and processing algorithms, a windows system, and network support. Both functions need a consistent user interface and an adaptable programming environment . The UNIX operating system running on a network of workstations meets the needs of image production and is very well suited to user interface and software development for both imaging and control. However, high performance real-time control is not possible under most available UNIX systems, but can be accomplished using a real-time kernel running on separate hardware. This suggests a multi-processor approach based on inter-process communication between the workstation and control environments. The architecture consists of three hardware layers (UNIX workstations, board-level microcomputers, and digital signal processors) and four software layers. The real-time software layers are DSP microcode and the microprocessor code. The lower layer of workstation software is a multi-tasked command-driven program tailored for instrument control and image production. The top layer of workstation software consists of an icon or menu driven user interface. A research instrument for nuclear magnetic resonance imaging will serve as an example of this approach.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Thermodynamics of Carbon Monoxide Binding by Helical Hemoprotein Models: the Effect of a Competing Intramolecular Ligand

Abstract Ferrous hemoprotein models 1 and 2 exhibit bis-histidine/mono-histidine coordination equilibrium in aqueous solution. Carbon monoxide binds more tightly to 1 than to 2, a result of stronger Fe(II)–His coordination in 2 arising from interactions between the Trp side chain and the porphyrin ring. Coordination of the more weakly bound histidine ligands to Fe(II) in 1 is shown to be enthalpically favored but entropically disfavored due to the accompanying change in peptide conformation from random coil to α-helix. We demonstrate that competition from the intramolecular His ligand in 1 reduces ΔH° of CO binding compared to the mono-His coordinated form of the compound, an effect which is largely compensated by the positive entropy term due to unwinding of the peptide helix. Trading enthalpic stabilization of an Fe-ligand bond for an entropy gain due to a protein conformational change may be a common mode of action for hemoproteins which function as small molecule sensors.
Ecological Studies and Mathematical Modeling of Cladophora in Lake Huron: 5. Model Development and Calibration

The development of a mathematical model for calculating the spatial distribution and temporal variation in Cladophora biomass and selected forms of phosphorus at a site on Lake Huron is described. The model is intended for use in evaluating the utility of various phosphorus management strategies in reducing the nuisance growth of Cladophora in the Great Lakes. The model is composed of a transport component which accounts for bulk transfer and exchange of phosphorus within the system and a kinetic component which describes chemical and biological reactions. The kinetic component includes the effects of light, temperature, and internal phosphorus levels on Cladophora growth rate, aspects of phosphorus uptake, and the impact of sloughing and self-shading on standing crop. The numerical value of coefficients associated with kinetic equations have been independently determined through laboratory studies. The model has been calibrated to a data set collected in the vicinity of the Harbor Beach, Michigan, wastewater treatment plant. A satisfactory fit was achieved for model calculations and observed levels of Cladophora biomass, internal phosphorus, and soluble reactive phosphorus. The model has few degrees of freedom because the coefficient values were fixed from field and laboratory measurements. A standing crop of Cladophora biomass of 300 gDW/m2 with an internal phosphorus level of 0.35%P was characteristic of stations in the vicinity of the nutrient source. Soluble reactive phosphorus levels fluctuated widely due to mixing of the effluent plume with offshore waters, but averaged approximately 30 μgP/L. A distinct spatial trend was observed with Cladophora biomass, internal phosphorus, and soluble reactive phosphorus decreasing with distance from the point source of nutrients. The opportunity for model verification by perturbation through phosphorus removal is discussed.
Prospective Maritime Jurisdictions in the Polar Seas

ABSTRACT The maps illustrate the possible extent of the 200-nautical-mile exclusive economic zone in the polar regions. They also show the 500 m and 2,500 m isobaths as they relate to prospective economic zones. Equidistance lines are shown between countries, and where negotiated maritime boundaries exist these too are shown. The maps and accompanying text indicate where disputes may eventually arise over maritime jurisdictions as nations begin claiming sovereignty over offshore areas.
PI3K isoform dependence of PTEN-deficient tumors can be altered by the genetic context

There has been increasing interest in the use of isoform-selective inhibitors of phosphatidylinositide-3-kinase (PI3K) in cancer therapy. Using conditional deletion of the p110 catalytic isoforms of PI3K to predict sensitivity of cancer types to such inhibitors, we and others have demonstrated that tumors deficient of the phosphatase and tensin homolog (PTEN) are often dependent on the p110β isoform of PI3K. Because human cancers usually arise due to multiple genetic events, determining whether other genetic alterations might alter the p110 isoform requirements of PTEN-null tumors becomes a critical question. To investigate further the roles of p110 isoforms in PTEN-deficient tumors, we used a mouse model of ovarian endometrioid adenocarcinoma driven by concomitant activation of the rat sarcoma protein Kras, which is known to activate p110α, and loss of PTEN. In this model, ablation of p110β had no effect on tumor growth, whereas p110α ablation blocked tumor formation. Because ablation of PTEN alone is often p110β dependent, we wondered if the same held true in the ovary. Because PTEN loss alone in the ovary did not result in tumor formation, we tested PI3K isoform dependence in ovarian surface epithelium (OSE) cells deficient in both PTEN and p53. These cells were indeed p110β dependent, whereas OSEs expressing activated Kras with or without PTEN loss were p110α dependent. Furthermore, isoform-selective inhibitors showed a similar pattern of the isoform dependence in established Kras(G12D)/PTEN-deficient tumors. Taken together, our data suggest that, whereas in some tissues PTEN-null tumors appear to inherently depend on p110β, the p110 isoform reliance of PTEN-deficient tumors may be altered by concurrent mutations that activate p110α.
Packing columns for capillary electrochromatography

Considering the current interest in capillary electrochromatography (CEC), performed in packed columns, we present the different methods used to pack capillary columns for use in CEC. General considerations on column packing are given and the column fabrication process is discussed in sufficient detail to allow instruction to those who are not experienced in the field. Five different packing methods are discussed to deliver packing material into the capillary column from a practical view point: slurry pressure packing, packing with supercritical CO2, electrokinetic packing, using centripetal forces, and packing by gravity. Entrapment of particulate material by sintering and sol-gel technology is also mentioned. Although slurry pressure packing procedures are most common, higher separation efficiencies are obtained using other packing approaches. Electrokinetic packing seems to be the simplest technique to deliver the packing material into the capillary columns. Nevertheless, as with the other packing techniques, skill and experience are required to complete all the steps involved in the fabrication of packed columns for CEC.
Carbon monoxide poisoning. Early awareness and intervention can save lives

PREVIEWEach year, particularly during the heating season, thousands of people are poisoned by carbon monoxide, with potentially devastating outcomes. Initial diagnosis can be difficult because symptoms closely resemble those of influenza and are often misinterpreted. Dr Tomaszewski discusses diagnosis and treatment, including the benefits and risks of hyperbaric oxygen therapy.
Greedy Motion Planning for Simultaneous Signal Landscape Mapping and Receiver Localization

Greedy motion planning strategies to enhance situational awareness in an opportunistic navigation (OpNav) environment are considered. An OpNav environment can be thought of as a radio frequency signal landscape within which a receiver locates itself in time and space by extracting information from ambient signals of opportunity (SOPs). The receiver is assumed to draw only pseudorange observations from the SOPs. The following problem is considered. A receiver with no a priori knowledge about its own initial states nor the initial states of multiple SOPs, except for one, is dropped in an OpNav environment. Assuming that the receiver can prescribe its maneuvers, what greedy (i.e., one-step look-ahead) motion planning strategy should the receiver adopt so to optimally build a high-fidelity signal landscape map of the environment while simultaneously localizing itself within this map in time and space with high accuracy? Several information-based and innovation-based motion planning strategies are studied. It is shown that with proper reformulation, the innovation-based strategies can be cast as tractable convex programs, the solution of which is computationally efficient. Simulation results are presented comparing the various strategies and illustrating the improvements gained from adopting the proposed strategies over random and predefined receiver trajectories.
Organising principles for international advocacy associations

Recent decades have witnessed a significant increase in the number of voluntary non-profit associations established to address solutions to major international social problems. Many of these associations concentrate on advocacy work, as opposed to service delivery, and are international in scope rather than based in a single country. This paper is concerned with the challenges to organising this particular type of voluntary association.
Selectivity nomographs for classical filters

Nomographs for determining the filter order of classical filters based on selectivity requirements are presented. The selectivities for a variety of standard classical filters are summarized in equation form and the general selectivity nomograph is constructed. The selectivity equations are then converted into nomograph form by applying the relationship between the transfer function and the response slope. Design examples are presented to demonstrate the usefulness of the selectivity nomographs. These nomographs can be used to gauge filter performance and combined with optimization techniques can yield superior classical filter designs.
A circuit which expands the count storage capacity of a multichannel analyzer

Abstract A circuit has been designed which allows the experimenter to store up to 1010 counts/channel in a 105 count capacity multichannel analyzer. The circuit uses the analyzer's second subgroup to store the overflow counts of the first subgroup. The circuit was designed to be used with an analyzer operating in the multichannel scaling mode.
Oogenesis in the ocelliless mutant of Drosophila melanogaster Meigen (Diptera: Drosophilidae)

Abstract Female fruitflies homozygous for the sex-linked gene ocelliless (oc) are sterile. Their ovaries contain normal sized eggs in which are found reduced numbers of beta yolk spheres. These are abnormally large and differ in their cytochemical properties. Normal beta yolk spheres are rich in glycogen, are intensely PA/S-positive, and are made up of particles that bind lead citrate. Giant yolk spheres from the mutant give weak PA/S reactions and bind little lead. The chorion of oc eggs is also defective.
Developmental changes in infant-stranger interaction

Although considerable attention has been given to the phenomenon of “stranger anxiety,” we still do not know some of the behavioral characteristics of strangers associated with infants' wariness of strangers and how these may change with development. We also have not systematically examined the ways in which adults may vary their behavior as a function of the age of the child. The following study addresses these issues. Seventy-five infants (25 in each group of 6-, 12-, and 18-month-olds) were videotaped interacting with three strangers sequentially. One stranger (the “standard stranger”) interacted with all of the infants first. The other strangers ( N = 50) each interacted with three infants, one from each age group. The videotapes were coded for various aspects of infant and stranger behavior. Six-month-olds were more positive with strangers who showed more positive affect and who did not touch them. In contrast, 12- and 18-month-olds' reactions were related to aspects of the stranger behavior such as controllability and sensitivity. Strangers behaved very differently with 18-month-olds than with the younger infants, allowing them more control in the interaction. Maternal reports of their infants' reactions to strangers obtained before the laboratory visit were significantly related to infant behavior observed in the lab.
Heterogeneous Samples in Organizational Research

The utility of heterogeneous versus homogeneous samples in comparative organizational research is appraised through a path analytic comparison of the relationships between organizational size, spatial, vertical and horizontal differentiation established with samples representing different degrees of homo-heterogeneity. A causal model is estimated on data of 115 business and government organizations. The estimated parameters of the model are compared to those of Blau and Schoenherr based on a homogeneous sample of employment agencies, and Mileti, Gillespie, and Haas's sample of mixed government agencies. The findings suggest the potential utility of increasing our use of heterogeneous samples in comparative organizational research.
Prenatal opiate exposure impairs radial arm maze performance and reduces levels of BDNF precursor following training

Abstract Prenatal exposure to opiates, which is invariably followed by postnatal withdrawal, can affect cognitive performance. To further characterize these effects, we examined radial 8-arm maze performance and expression of brain derived neurotrophic factor (BDNF) in male rats prenatally exposed to the opiate l -α-acetylmethadol (LAAM). Female rats received 1.0 mg/kg/day LAAM or water via daily oral gavage for 28 days prior to breeding, during breeding, and throughout pregnancy. Pups were fostered to non-treated lactating dams at birth and underwent neonatal opiate withdrawal. At 5–6 months, prenatal water- and LAAM-exposed males ( n = 6 each; non-littermates) received radial arm maze training consisting of ten trials a day for five days and three retention trials on day six. Rats prenatally exposed to LAAM had poorer maze performance, decreased percent correct responding and more reference and working memory errors than prenatal water-treated controls. However, they were able to acquire the task by the end of training. There were no differences between the groups on retention 24 h after testing. Following retention testing, hippocampi were removed and protein extracted from cytosol and synaptic fractions. Western blots were used to measure levels of mature and precursor BDNF protein, as well as the BDNF receptor TrkB. BDNF precursor protein was significantly decreased in the synaptic fraction of trained prenatal LAAM-treated rats compared to prenatal water-treated trained controls. No effects were found for the full-length or truncated TrkB receptor. In untrained rats, prenatal treatment did not affect any of the measures. These data suggest that prenatal opiate exposure and/or postnatal withdrawal compromise expression of proteins involved in the neural plasticity underlying learning.
A single turnover investigation of the palladium on phosphinated oxide catalysts

Abstract A series of catalysts composed of Pd metal supported on inorganic oxides having pendant phosphine groups on their surfaces was subjected to single turnover (STO) reaction characterization. It was found that the nature of the oxide support and the pendant phosphine both influence STO product formation. Alumina-supported catalysts produce less isomerization than do those supported on silica-magnesia or silica. Alkyldiarylphosphinecontaining catalysts give more stable metal alkyl formation than those having a triarylphosphine group.
Early invasive strategies for acute coronary syndromes

Early coronary angiography and percutaneous or operative revascularization is now the treatment of choice for both ST- and non-ST-segment elevation acute coronary syndromes (ACS). In non-ST-segment elevation ACS this strategy produces a 18% to 22% reduction in ischemic outcomes at 6 months and prevents 1.7 deaths, 2.0 nonfatal infarcts and 20 readmissions per 100 treated patients at 1-year follow-up. Early angiography allows definition of coronary anatomy and assessment of left ventricular function, both important predictors of long-term risk. Intracoronary stenting and intravenous glycoprotein IIb/IIIa antagonists have improved outcome in percutaneous revascularization and should be used in the majority of ACS patients undergoing PCI. Initial costs are higher with an early invasive strategy; however, these are offset by reductions in rehospitalizations and later ischemic complications.