cssi/SciSciGPT-SciSciNet huggingface dataset:
Realizing the Potential of Carotid Artery Stenting Proposed Paradigms for Patient Selection and Procedural Technique

Carotid artery stenting, compared with carotid endarterectomy, is emerging as an effective and less invasive method of revascularization for extracranial carotid artery stenosis. Carotid stenting is established as the treatment of choice for certain high-risk patient subsets, and ongoing clinical trials are evaluating this method across a broader clinical spectrum, including asymptomatic patients. For carotid stenting to reach its full potential, an acceptable risk of periprocedural complications, particularly in low-risk patients, must be ensured (the “3% rule”). The present article provides an in-depth review of carotid stenting, with special emphasis on the process of risk stratification pertaining to clinical, anatomic, and procedural considerations necessary to optimize procedural safety and patient outcomes.
The Arachne Myth in Oral and Written Literature

In his paper, "The Arachne Myth in Oral and Written Literature," Jose Manuel Pedrosa explores the folktale about a person who prides himself being the most intelligent individual and whom the gods punish with a metamorphosis into spider. Pedrosa discusses similar myths in existence in modern oral traditions and in literary works such as the Bible, Ovid's Metamorphoses, the Quran, and Garcia Marquez's masterpiece Cien anos de soledad. The universality of the myth is underlined by the existence of a folktale registered among the Bubi people of Equatorial Guinea. Not known about it until the twentieth century, the oral transmission or survival of this tale proves of extraordinary importance and the reason why the Bubi text may be considered a rare record and a true jewel capable of providing valuable information about the folk myths and basic beliefs that have inspired many geniuses of Western literature. Jose Manuel Pedrosa, "The Arachne Myth in Oral and Written Literature" page 2 of 9 CLCWeb: Comparative Literature and Culture 7.1 (2005):
A Comparison of Bacteria Counts in Whole and Skim Milk, Separator and Centrifuge Cream

Summary These results indicate quite strongly that there are usually less or only slightly more bacteria in separator cream than in the whole milk from which separated. Also that centrifugally raised cream in closed container showed from six to twenty-five times as many bacteria as were found in the original milk. The skim milk usually contained fewer bacteria than the whole milk. There does not appear to be any sharp relation between increase in butter fat, at least above 25. per cent, and the percentage of bacteria found in the cream. These results for separator cream are in quite close agreement with the findings of other investigators who actually worked on separator cream. The results obtained on centrifuge cream are also very similar to those reported by other writers on this class of product. The comparison between the two types of cream from the same whole milk indicates that it is erroneous to interpret the results on centrifuge cream as comparable to what would be found in commercial separator cream. From this and other investigations on commercial separated cream it would appear desirable to have a common bacteriological standard for market whole milk and cream.
Cytogenetic and mutagenic effects of DDT and DDE in a Chinese hamster cell line.

Abstract The mutagenic and cytogenetic effects of the chlorinated hydrocarbon 1,11-trichloro-2,2-bis( p -chlorophenyl)ethane] (DDT), and its metabolite [1,1-dichloro-2,2-bis( p -chlorophenyl)ethylene] (DDE) were investigated in vitro using a Chinese hamster cell line. A forward mutation system utilizing the 8-azaguanine sensitive to 8-azaguanine resistant marker was used as the index of mutagenic action. Methyl methanesulfonate (MMS) was used as the positive control. In all experiments, DDE consistently produced a significant increase in the mutation frequency over the control level, while DDT proved inactive. Resultsof the cytogenetic studies indicated that DDE-treated cells had a significant increase in chromosome aberrations over those occuring in the control population; exchange figures and chromatid breaks wre evident. DDT produced no significant increase in chromosome abnormalities. The Chinese hamster cell populations exposed to DDE also manifested an increased number of polyploid cells over the control level.
3-D world modeling for an autonomous robot

This paper presents a methodology for a concise representation of the 3-D world model for a mobile robot, using range data. The process starts with the segmentation of the scene into "objects" that are given a unique label, based on principles of range continuity. Then the external surface of each object is partitioned into homogeneous surface patches. Contours of surface patches in 3-D space are identified by estimating the normal and curvature associated with each pixel. The resulting surface patches are then classified as planar, convex or concave. Since the world model uses a volumetric representation for the 3-D environment, planar surfaces are represented by thin volumetric polyhedra. Spherical and cylindrical surfaces are extracted and represented by appropriate volumetric primitives. All other surfaces are represented using the boolean union of spherical volumes (as described in a separate paper by the same authors). The result is a general, concise representation of the external 3-D world, which allows for efficient and robust 3-D object recognition.
Photosynthetic physiology and physicochemical forcing in the Arabian Sea, 1995

Abstract The Arabian Sea, characterized by strong seasonal monsoonal forcing as well as prolific mesoscale features, is a complex hydrographic environment for phytoplankton photosynthesis. Previous studies have demonstrated seasonal cycles in both primary production and photosynthetic biomass that may be related to patterns of photosynthetic efficiency, but the magnitude of water column efficiency is high throughout the year suggesting that other mechanisms may be operating. To uncover the patterns and regulation of photosynthetic efficiency on the synoptic scale (basin-wide, seasonal dynamics), here we focus on the relationship between physicochemical forcing such as nitrate concentrations and mixed layer depth and photophysiology. These observations, which are from a transect from the coast of Oman to about 1400 km offshore in the Arabian Sea at 65E, were made on five US JGOFS Arabian Sea Process cruises conducted between March and December 1995. Parameters of photosynthesis as quantified by pigmentation, photosynthesis-irradiance curves and spectral absorption properties were spatially and temporally variable, but demonstrate several marked trends. During the early Southwest Monsoon, when nitrate concentrations were elevated, maximum quantum yield of carbon uptake ( φ C,max , 0.051±0.024 mol C mol Q −1 ) and light-utilization coefficients ( α B , 0.040±0.016 mg C mg Chl a −1 h −1 (μmol Q m −2 s −1 ) −1 ) were increased and non-photosynthetic pigment indices (NPP i , 0.339±0.089 g g −1 ) and chlorophyll a -specific mean absorption ( σ Chl a , 0.032±0.012 m 2 mg Chl a −1 ) were typically reduced compared to the Spring and Fall intermonsoon seasons ( φ C,max , 0.020±0.009; α B , 0.025±0.011; NPP i , 1.065±0.173; σ Chl a , 0.058±0.018). These patterns are in part driven by some significant correlations between mixed layer depth and nitrate concentrations and NPP i , φ C,max , α B and σ Chl a at the synoptic scale. However, other factors not measured here such as time-lagged processes may also be important to the overall variability of photosynthetic physiology. In general, photosynthetic efficiency as measured by φ C,max suggests phytoplankton populations that are exceptionally photosynthetically efficient during the SW Monsoon period, while at other times of the year efficiency may be a contributing factor to the limitation of primary production.
High concentration versus incremental induction of anesthesia with sevoflurane in children: A comparison of induction times, vital signs, and complications

Abstract Study Objective : To compare sevoflurane induction times and complications in children during a high concentration, primed-circuit method and an incremental induction technique. Design : Randomized, prospective open-label study. Setting : Academic university hospital. Patients : 40 unpremeditated ASA physical status I and II children age 4 months to 15 years undergoing elective surgical procedures with general anesthesia. Interventions : Patients were randomized to one of two study groups. In the high concentration group, the anesthesia circuit was primed with 8% sevoflurane in a 2:1 nitrous oxide:oxygen (N 2 O:O 2 ) mixture. Patients breathed this gas mixture spontaneously until loss of the eyelash reflex. In the incremental group, the face mask was applied and 1% sevoflurane in a 2:1 N 2 O:O 2 mixture was administered. In this group, the sevoflurane concentration was increased by 1% every 2 to 3 breaths. Gas flows of 6 L/min were administered to both groups during the study period. Following loss of the eyelash reflex, the sevoflurane concentration was decreased to 5% until a depth of anesthesia sufficient to start an intravenous catheter was achieved. Measurements and Main Results : Induction cooperation, induction time (face mask application to loss of the eyelash reflex), one-minute vital signs [blood pressure, heart rate, oxygen saturation via pulse oximetry (SpO 2 )], induction complications. Induction of anesthesia was faster in the high concentration group than in the incremental group (mean (SD) 42 (9) sec vs. 66 (12) sec, respectively; p 2 differences during induction. No patients required treatment for hypotension or bradycardia. Conclusions : In healthy pediatric patients undergoing mask induction of general anesthesia with sevoflurane, the induction time can be significantly shortened without an increase in the frequency of airway or vital sign complications using a high concentration, primed circuit technique compared with a conventional, incremental induction method.
Planet hunters and seafloor explorers: legitimate peripheral participation through practice proxies in online citizen science

Making visible the process of user participation in online crowdsourced initiatives has been shown to help new users understand the norms of participation [2]. However, in many settings, participants lack full access to others' work. Merging the theory of legitimate peripheral participation [18] with Erickson and Kellogg's theory of social translucence [10, 11, 16] we introduce the concept of practice proxies: traces of user participation in online environments that act as resources to orient newcomers towards the norms of practice. Through a combination of virtual [14] and trace ethnography [12] we explore how new users in two online citizen science projects engage with these traces of practice as a way of compensating for a lack of access to the process of the work itself. Our findings suggest that newcomers seek out practice proxies in the social features of the projects that highlight contextualized and specific characteristics of primary work practice.
Application of Exploration Play-Analysis Techniques to the Assessment of Conventional Petroleum Resources by the USGS

Exploration play-analysis methods are designed for individual or conceptual exploration plays to assess conventional petroleum resources. Play-analysis techniques usually are applied to a small area of appraisal, such as a geologic trend comprising a series of stratigraphic traps or structural traps. Play-analysis procedures, incorporating Monte Carlo techniques, also have been applied to entire geologic horizons, formations, or stratigraphic units of a geologic basin or province. The application of exploration play-analysis techniques to broad frontier provinces for the assessment of conventional petroleum resources by the USGS are reviewed and the results for the Natl. Petroleum Reserve of Alaska (NPRA) and the William O. Douglas Arctic Wildlife Range (WODAWR) are discussed. 15 refs.
Feeding Cholesterol and Tallow in Liquid Diets to Veal Calves

Abstract Thirty-six Holstein bull calves were raised to 16 wk on five liquid diets containing skim milk plus either 3.5% milk fat, 3.5% tallow, 3.5% tallow and .2% cholesterol, 7.0% tallow, or 7.0% tallow and .2% cholesterol. Diets were fed at 10% of body weight by nipple pail to preserve the esophageal groove reflex. Intakes of dry matter, gains of body weight, and feed refusals were greater for calves fed 7.0% tallow. Concentrations of lipid and cholesterol in blood plasma increased markedly (2 to 3 times) in calves fed cholesterol. Thyroxine and triiodothyronine concentrations in plasma were highest in calves showing the most growth response. Weight of liver was elevated both by feeding high tallow and by feeding cholesterol. Liver fat was elevated more by feeding .2% cholesterol than by doubling dietary fat. Yield of trimmed veal was 14% greater when diets included cholesterol and 7.0% tallow or 7.0% tallow than when they were 3.5% tallow or milk fat. Feeding liquid tallow can be successful in veal production when ingredient costs are advantageous. Economics of ingredient selection is discussed. Further research utilizing different concentrations of tallow and higher intake is needed.
Identifying the n = 2 reaction mechanism of FAD through voltammetric simulations

In a previous study [E.T. Smith, C.A. Davis, M.J. Barber, Anal. Biochem. 323 (2003) 114–121], cyclic voltammograms were simulated using DigiSim software for reaction mechanisms involving multiple electron transfer steps coupled to proton transfer. Specifically, the overall reaction mechanism of the form: FAD + 2e − +2 H + FADH2 was used to simulate experimental reduction potentials as a function of pH. Experimental observations for free FAD were simulated based on selected reduction potentials and acid dissociation constants for three different reaction mechanisms. In this study, these three reaction mechanisms were examined further using simulations of concentration profiles to identify species that are present in significant concentrations during the electron transfer process. These concentration profiles can then be used as working curves to identify reaction mechanisms and equilibrium constants. For example, two of the three reaction mechanisms, both of which involve a redox reaction coupled to a single proton, indicate significant formation of the semiquinone species at the electrode surface at high pH and low potentials. Previous spectroscopic studies of flavoproteins with an n = 2 reaction mechanism have been unable to detect the formation of a semiquinone under any experimental conditions. Thus, the most reasonable pathway for a proton-coupled n =2 reaction mechanism is likely to involve two protons. © 2005 Elsevier B.V. All rights reserved.
Transmission Line Design Mechanical Design of Spans With Supports at Unequal Elevations

The purpose of this paper is to derive a practical method of design based upon the catenary formulas for spans whose supports are not at the same elevation. It is furthermore intended completely to formulate the method for applying it to any cable which is suspended freely or is uniformly loaded, as well as for obtaining its characteristics after the temperature or loading conditions of the cable have changed. After a brief survey of the present need for more accurate methods of mechanical design of transmission line cables, the several formulas which are adapted to spans with supports at unequal elevations are given, and the method of using them is fully explained. All such special formulas are fully derived in the appendix. The first method given depends somewhat upon interpolated values from the symmetrical span data. A second pure interpolation method is next described which has the advantage of being shorter than the first as well as more accurate, since it depends upon fewer interpolated values from mathematical tables. The use of these two methods is then fully illustrated by the solution of three typical spans. Data for the cable used in symmetrical spans are first given, and from these the solution for the span with supports at unequal elevation is obtained. For the purpose of comparison the computations used in obtaining the desired values by each method are given in full for one of the spans chosen.
Inhibition of viral hemagglutination by brain ganglioside.

Abstract A purified preparation of brain ganglioside, a macromolecular glycolipid whose structure has been recently considerably clarified, is here shown to act as an inhibitor of PR8 influenza virus hemagglutination. Purified fractions separated from the intact ganglioside by stepwise hydrolytic cleavage, have also been tested. The neuraminic acid-hexosamine moiety appears to be essential for the inhibition. The possibility is considered that this moiety, present in both gangliosides and mucoproteins, is associated with both the attachment of the virus particle to the host cell and the transfer of the virus nucleic acid into the cell.
Using Electronic Mail (E-mail) Surveys for Geographic Research: Lessons from a Survey of Russian Environmentalists∗

The expansion of the Internet and e-mail access around the globe, especially into less-developed areas, raises the question of how geographers might use this technology for research purposes and the development of appropriate methodologies. This paper identifies three ways in which the use of e-mail surveys for geographic research differs from traditional mail surveys. First, there are substantial differences in selecting an appropriate sample population. Second, electronic medium considerations such as alphabet character translation, survey format, and receiving end conditions pose unique data collection challenges. Third, ascertaining that e-mail addresses to be included in a survey are operative is discussed as a useful means of maximizing the potential of an e-mail survey. Examples from an e-mail survey of environmentalists in Russia illustrate these points.
Relationships Between Personality and Preferred Substance and Motivations for Use Among Adolescent Substance Abusers

This study examined the utility of Cloninger's tridimensional personality theory (1986, 1987a) in predicting preferred substance of abuse and self-reported motivations for use among a sample of 200 adolescent substance abusers and 200 matched community control adolescents. Two primary hypotheses were tested: (1) Cloninger's type II profile is more strongly associated with stimulant use, and his type I profile is more strongly associated with substances having sedative-hypnotic effects; and 2) type II individuals will report motivations for use that focus primarily on obtaining positive rewards, whereas type I individuals will report motivations primarily concerning negative reinforcement or the avoidance of problems and negative life experiences. Our results did not show strong associations between Cloninger's Harm Avoidance and Reward Dependence dimensions and preferred substance or motivations for use. However, in partial support of the hypotheses examined here, we did find that individuals low in novelty seeking (NS) tended to prefer alcohol and marijuana, whereas those high in NS endorsed a wider range of preferred substances. High NS was associated with significantly greater stimulant use and motivations focused on obtaining positive rewards, whereas low NS was associated with greater sedative use and motivations related to avoiding negative emotions or negative life experiences.
Heme oxygenase-1 upregulation protects against intestinal ischemia/reperfusion injury: A laboratory based study

Abstract Objectives Tissue damage caused by ischemia/reperfusion injury (IRI) of the intestine may lead to organ dysfunction in several clinical conditions, and is associated with increased incidence of chronic rejection after transplantation. Heme oxygenase-1 (HO-1) is a stress-inducible protein capable of modulating inflammation, oxidative stress, and cell death. The aim of the present study was to assess the effects of HO-1 upregulation on intestinal IRI. Methods Lewis rats (seven groups, n =6 each) underwent intestinal warm ischemia induced by clamping the superior mesenteric artery and by ligating the inferior mesenteric artery for 60min. After 120 or 240min of reperfusion, tissue samples were collected for analysis. Cobalt protoporphyrin (CoPP) was administered IP at 10 or 20mg/kg 24h before IRI, to induce HO-1 upregulation. Control animals received vehicle alone. Tissue injury measurements included the following: histological changes, tissue myeloperoxidase (MPO) activity, nitrate/nitrite levels, and IL-6 levels. Results A significant HO-1 upregulation was demonstrated in pre-treated animals ( p p p p Conclusions Induction of HO-1 by CoPP administration before IRI was resulted in a significant reduction of intestinal tissue injury. Developing strategies to induce HO-1 upregulation before surgery will be important to reduce IRI in the clinical setting.
Evolutionary Algorithm for Performance-Based Shear Wall Placement in Buildings Subjected to Multiple Load Types

Shear walls have very high in-plane stiffness and strength, which can be used to simultaneously resist large horizontal loads and support gravity loads, making them quite advantageous in many structural engineering applications. Structures must perform safely when subjected to numerous types of loading while still remaining aesthetic and fully functional. The nature of shear wall design in building structures is a difficult task, particularly if one wants to place the shear walls in such a way that the cost is minimal while still satisfying specific performance objectives when subjected to natural and human-induced loads. This paper presents the concept and formulation of an evolutionary algorithm for shear wall placement for several different load types under competing objectives and several simplified illustrative examples are presented for demonstration purposes. The example applications include cases for (1) static wind load; (2) dynamic blast load for a small car load of explosives; and (3) dynamic blast load for a semitrailer load of explosives. A three-dimensional finite-element model was developed and applied to analyze the performance requirements and was fully coupled in time with the evolutionary algorithm in order to identify the optimal solution. The evolutionary algorithm coupled with the numerical structural model presented herein shows promise for many different building subassemblies and components beyond shear walls. It is envisioned that this type of algorithm can be extended to include all types of building assemblies (i.e., columns and beams), resulting in an increased general robustness of building regardless of hazard type.
A role-based delegation framework for healthcare information systems

As organizations implement information strategies that call for sharing access to resources in the networked environment, mechanisms must be provided to protect the resources from adversaries. The proposed delegation framework addresses the issue of how to advocate selective information sharing in role-based systems while minimizing the risks of unauthorized access. We introduce a systematic approach to specify delegation and revocation policies using a set of rules. We demonstrate the feasibility of our framework through policy specification, enforcement, and a proof-of-concept implementation on specific domains, e.g. the healthcare environment. We believe that our work can be applied to organizations that rely heavily on collaborative tasks.
Producing simple utterances: Details of the planning process

Subjects produced subject-verb sentences of prespecified structure, such asThe man is kicking, in response to pictures. The amount of information required to identify the pictured actor or action and to retrieve a name for the actor was varied. The following results, based on subject response latencies, were obtained. Experiment I demonstrated that only some initial amount of verb information processing occurs before and delays the initiation of such subject-verb sentences. Experiment II demonstrated that verb information processing is initiated only after the subject of the sentence has been identified. Finally, Experiment III demonstrated that verb information processing is initiated in parallel with the retrieval of the name for the subject of the sentence.
The emergence of zoning policy games in exurban jurisdictions: Informing collective action theory

Abstract Theoretical urban policy literature predicts the likelihood of free riding in the management of common goods such as forested open space; such outcome is often characterized as a Prisoner's Dilemma game. Numerous cases exist in which neighboring jurisdictions cooperate to maintain public goods, challenging the expected results, yet theoretical explanations of these cases have not been fully developed. In this paper, we use an agent-based model to explore how underlying micro-behaviors affect the payoffs obtained by two neighboring municipalities in a hypothetical exurban area. Payoffs are measured in terms of regional forested space and of local tax revenue at the end of the agent-based simulations; the municipalities affect these payoffs through their choice of residential zoning policies and the spillover effect between the neighboring jurisdictions. Zoning restrictions influence the conversion of farmland into residential subdivisions of different types, and consequently the location of heterogeneous residential households in the region. Developers and residents respond to the changing landscape characteristics, thus establishing a feedback between early and future land-use patterns. The structure of the simulated payoffs is analyzed using standard game theory. Our analysis shows that a variety of games, in addition to Prisoner's Dilemma, can emerge between the neighboring jurisdictions. Other games encourage coordination or subsidization, offering some explanations for the unexpected observations. The game realized in any given context depends on the initial characteristics of the landscape, the value given to the objectives each township seeks to maximize, and the income distribution of the population.
Diet and esophageal cancer: A case-control study

Abstract A case control study of osophageal cancer was conducted among black male and female residents of Washington, D.C., to assess the influence of the intake of food groups, alcohol, and smoking to the esophageal cancer. Twenty-three pairs (23 cases and 23 controls) were interviewed. Cases ate more pork (p
B cell precursors in senescent mice exhibit decreased recruitment into proliferative compartments and altered expression of Bcl-2 family members

Abstract In vitro, aged pro-B cells generally exhibit limited expansion in response to IL-7 when compared to young pro-B cells. CFSE-labeling in vitro indicated that aged mice have a lower frequency of pro-B cells which are capable of undergoing extensive proliferation upon stimulation with exogenous IL-7. Protein levels of the survival molecule Bcl-x L were consistently reduced in IL-7 expanded aged pro-B cells. Levels of both Bcl-2 and Baxα proteins were variable in aged B cell precursors. The expansion of aged pro-B cells in response to IL-7 in vitro correlated inversely with the ratio of the pro-apoptotic protein Baxα to the survival protein Bcl-2. Expansion of aged pro-B cells in vitro is likely dictated by both recruitment of pro-B cells into proliferative compartments and their survival; in aged B cell precursors, the latter is favored by low Baxα to Bcl-2 protein ratios.
Many objective visual analytics: rethinking the design of complex engineered systems

Many cognitive and computational challenges accompany the design of complex engineered systems. This study proposes the many-objective visual analytics (MOVA) framework as a new approach to the design of complex engineered systems. MOVA emphasizes learning through problem reformulation, enabled by visual analytics and many-objective search. This study demonstrates insights gained by evolving the formulation of a General Aviation Aircraft (GAA) product family design problem. This problem's considerable complexity and difficulty, along with a history encompassing several formulations, make it well-suited to demonstrate the MOVA framework. The MOVA framework results compare a single objective, a two objective, and a ten objective formulation for optimizing the GAA product family. Highly interactive visual analytics are exploited to demonstrate how decision biases can arise for lower dimensional, highly aggregated problem formulations.
Transcriptional and Translational Regulation of β-Cell Differentiation Factor Nkx6.1

In the mature pancreas, the homeodomain transcription factor Nkx6.1 is uniquely restricted to β-cells. Nkx6.1 also is expressed in developing β-cells and plays an essential role in their differentiation. Among cell lines, both β- and α-cell lines express nkx6.1 mRNA; but no protein can be detected in the α-cell lines, suggesting that post-transcriptional regulation contributes to the restriction of Nkx6.1 to β-cells. To investigate the regulator of Nkx6.1 expression, we outlined the structure of the mouse nkx6.1 gene, and we identified regions that direct cell type-specific expression. Thenkx6.1 gene has a long 5′-untranslated region (5′-UTR) downstream of a cluster of transcription start sites.nkx6.1 gene sequences from −5.6 to +1.0 kilobase pairs have specific promoter activity in β-cell lines but not in NIH3T3 cells. This activity is dependent on sequences located at about −800 base pairs and on the 5′-UTR. Electrophoretic mobility shift assays demonstrate that homeodomain transcription factors PDX1 and Nkx2.2 can bind to the sequence element located at −800 base pairs. In addition, dicistronic assays establish that the 5′-UTR region functions as a potent internal ribosomal entry site, providing cell type-specific regulation of translation. These data demonstrate that complex regulation of both Nkx6.1 transcription and translation provides the specificity of expression required during pancreas development.
Electrical Conduction in a Noncircular Rod

The general constitutive equations for galvanomagnetic effects in isotropic materials are applied to the study of electrical conduction in rods. It is shown that, in general, rectilinear current flow is not possible, unless the rod has a circular cross section or is an infinite parallel‐sided slab.
The role of habitat selection behavior in population dynamics: source -sink systems and ecological traps

Ecological traps, poor-quality habitat that nonetheless attract individuals, have been observed in both natural and human-altered settings. Until recently, ecological traps were considered a kind of source--sink system, but source-sink theory does not model maladaptive habitat choice, and therefore cannot accurately represent ecological traps or predict their population-level consequences. Although recent models of ecological traps addressed this problem, they used patch-based models containing only two habitats that were very different from one another, but were internally homogeneous. These sorts of patch models may not apply to many real populations, and using them for populations in landscapes with mosaic or gradient habitat structures may be misleading. I developed models that treat source -sink dynamics and ecological traps as special cases of a single process, in which the attractiveness and quality of the habitat are separate variables that can be either positively or negatively related, and in which habitat quality varies continuously throughout the landscape. As expected, sinks are less detrimental to populations than ecological traps, in which preferential use of poor habitat elevates extinction risk. Furthermore, ecological traps may be undetected, and may even appear to be sources, when population sizes are large, but may still prevent recovery in spite of the availability of high-quality habitat when populations drop below threshold levels. Conservation biologists do not routinely consider the possibility that apparent sinks are actually traps, but since traps should be associated with the rapidly changing and novel habitat characteristics primarily produced by human activities, ecological traps should be considered an important and potentially widespread conservation concern.
Frequency of 13q Abnormalities Among 203 Patients With Retinoblastoma

We studied peripheral blood lymphocyte karyotypes of 203 patients with retinoblastoma. Twelve (5.9%) had a constitutional chromosomal abnormality involving 13q, of whom six had unilateral and six had bilateral disease. Two patients had mosaic deletions, eight had nonmosaic deletions, one had a de novo translocation, and one had a 13q14 deletion and a de novo direct insertion (10;6). Of the total, 4.9% of unilateral and 7.5% of bilateral patients had 13q abnormalities. None of 19 familial retinoblastoma patients had a visible cytogenetic abnormality. The unilateral patients with 13q abnormalities represent prezygotically determined (potentially heritable) cases which would have been classified as postzygotic (sporadic) without cytogenetic analysis. The observed 1% frequency of mosaic deletions is lower than that previously reported.
Visual Recognition As Soon as You Know It Is There, You Know What It Is

What is the sequence of processing steps involved in visual object recognition? We varied the exposure duration of natural images and measured subjects' performance on three different tasks, each designed to tap a different candidate component process of object recognition. For each exposure duration, accuracy was lower and reaction time longer on a within-category identification task (e.g., distinguishing pigeons from other birds) than on a perceptual categorization task (e.g., birds vs. cars). However, strikingly, at each exposure duration, subjects performed just as quickly and accurately on the categorization task as they did on a task requiring only object detection: By the time subjects knew an image contained an object at all, they already knew its category. These findings place powerful constraints on theories of object recognition.
Young Adults and Parental Divorce: Exploring Important Issues

In this article, the potential impact ofparental divorce on the lives of young adult offspring is discussed. Parental divorce may upset both social and psychological aspects of the transition to adulthood process. The family roles young adults are expected to assume could be altered by the break-up, as could opportunities for particularyoung adult pursuits, such as advanced education. Heightened adjustment problems also are likely to result, as divorce produces additional life changes during the highly transitional period of early adulthood. Qualitative data from an exploratory study of 39 college students, ages 18-23, illustrate many of the relevant issues. Suggestions for future research are provided.
Stacked Density Estimation

In this paper, the technique of stacking, previously only used for supervised learning, is applied to unsupervised learning. Specifically, it is used for non-parametric multivariate density estimation, to combine finite mixture model and kernel density estimators. Experimental results on both simulated data and real world data sets clearly demonstrate that stacked density estimation outperforms other strategies such as choosing the single best model based on cross-validation, combining with uniform weights, and even the single best model chosen by "cheating" by looking at the data used for independent testing.
Device and Technology Challenges for Nanoscale CMOS

With the introduction of 90 nm node technology, silicon CMOS is already at the nanoscale. There is no doubt that the semiconductor industry desires to stay on the historical rate of cost/performance/density improvement as exemplified by the International Technology Roadmap for Semiconductors (ITRS). The challenges for continued device scaling are daunting. At the highest level, the challenges are: (1) delivering cost/performance improvement while at the same time containing power consumption/dissipation, (2) control of device variations, and (3) device/circuit/system co-design and integration. New devices and new materials offer new opportunities for solving the challenges of continued improvement. In this talk, we give an overview of the device options being considered for CMOS logic technologies from 45 nm to 22 nm and beyond. Technology options include the use of device structures (multi-gate FET) and transport-enhanced channel materials (strained Si, Ge). Beyond the 22 nm node, research are underway to explore even more adventurous options such as III-V compound semiconductors as channel materials, metal Schottky source/drain. Beyond that time horizon, there is the question of whether new materials and fabrication methods such as carbon nanotubes, semiconductor nanowires and self-assembly techniques will make an impact in nanoscale CMOS technologies. We survey the state-of-the-art of these emerging devices and technologies and discuss the research opportunities going forward. We conclude with a discussion of the interaction between device design and the circuit/system architecture and how this interaction will change the landscape of technology development in the future.
In Harm's Way: Childbearing Women and Nicotine

In the United States cigarette smoking accounts for 11% of deaths of women. Approximately one of every four women smoke. Among pregnant women, 20-50% smoke, although prevalence rates vary depending upon income, age, and educational level. Spontaneous quit rates are highest among pregnant smokers. Interventions have been used to assist pregnant women to stop smoking, and the use of a combination of methods has yielded the highest quit rates among pregnant women, but postpartum relapse rates provide a glimpse of the short-term benefit of these intense efforts. Smoking cessation interventions for pregnant women must be considered within the larger context of women's lives to promote permanent smoking cessation.
Glycomics of proteoglycan biosynthesis in murine embryonic stem cell differentiation.

stem cells (mESCs) differentiate to embryoid bodies (EBs) and to extraembryonic endodermal cells (ExE) to better understand the role of GAGs in stem cell differentiation. Hyaluronan synthesis was enhanced by 13- and 24-fold, most likely due to increased expression of hyaluronan synthase-2. Chondroitin sulfate (CS)/dermatan sulfate (DS) synthesis was enhanced by 4- and 6-fold, and heparan sulfate (HS) synthesis was enhanced by 5- and 8-fold following the transition from mESC to EB and ExE. Transcripts associated with the synthesis of the early precursors were largely unaltered, suggesting other factors account for enhanced GAG synthesis. The composition of both CS/DS and HS also changed upon differentiation. Interestingly, CS type E and highly sulfated HS both increase as mESCs differentiate to EBs and ExE. Differentiation was also accompanied by enhanced 2-sulfation in both CS/DS and HS families. Transcript levels for core proteins generally showed increases or remained constant upon mESC differentiation. Finally, transcripts encoding selected enzymes and isoforms, including GlcNAc4,6-O-sulfotransferase, C5-epimerases, and 3-O-sulfotransferases involved in late GAG biosynthesis, were also enriched. These biosynthetic enzymes are particularly important in introducing GAG fine structure, essential for intercellular communication, cell adhesion, and outside-in signaling. Knowing the changes in GAG fine structure should improve our understanding the biological properties of differentiated stem cells.
A permanent, functional, esthetic incisal-angle restoration

C o m p o s i t e , filled, and unfilled resins are currently in use as esthetic restorative materials for the incisal angle of anterior teeth. Pins, positive internal retention, and acid etching techniques are used to retain the acrylic resins. Some physical properties of the available resins lessen their acceptability as permanent functional restorations. This report proposes a Class IV cast gold restoration with a facing as an alternative. The composite, filled, and unfilled resins leave much to be desired with respect to permanence (Figs. 1, A and B), and are considered interim treatment? The resins have little potential for protecting the enamel incisal edge from occlusal abrasion. The Class IV pinledge inlay is a functional, permanent, esthetic alternative for restoring the incisal angle of anterior teeth. Esthetics are satisfied in the cast proximal incisal restoration when the contour of a labial void in the gold is restored with a self-curing methyl methacrylate acrylic resin. Deficiencies in the resin materials have become obvious with extended clinical exposure. The current status of the acrylic resins, as stated by the Council on Dental Materials and Devices, is as follows: "[their use] as an esthetic material in restorative dentistry has not been completely successful . . . . The direct filling resins, like the silicate cements, are not very satisfactory in Class IV restorations but are frequently used. ''~ There is much less resistance to the abrading forces of occlusion than was first thought. One manufacturer admits to this fact and urges prudence in planning restorations that will function in occlusionY The filled and composite resins have provided greater resistance to abrasion than has the unfilled material, as proved in conventional laboratory abrasion tests4: In support, others have shown the composite resins to be highly resistant to indentation, which would be proportional to abrasion resistance found clinically?, '; Long-term clinical studies of the filled material have been disappointing. However, there is increasing evidence that contraindicates the use of composite resins for Class I I and most Class I restorations. 7 In
Inhibition of "self" engulfment through deactivation of myosin-II at the phagocytic synapse between human cells.

Phagocytosis of foreign cells or particles by macrophages is a rapid process that is inefficient when faced with “self” cells that display CD47—although signaling mechanisms in self-recognition have remained largely unknown. With human macrophages, we show the phagocytic synapse at cell contacts involves a basal level of actin-driven phagocytosis that, in the absence of species-specific CD47 signaling, is made more efficient by phospho-activated myosin. We use “foreign” sheep red blood cells (RBCs) together with CD47-blocked, antibody-opsonized human RBCs in order to visualize synaptic accumulation of phosphotyrosine, paxillin, F-actin, and the major motor isoform, nonmuscle myosin-IIA. When CD47 is functional, the macrophage counter-receptor and phosphatase-activator SIRPα localizes to the synapse, suppressing accumulation of phosphotyrosine and myosin without affecting F-actin. On both RBCs and microbeads, human CD47 potently inhibits phagocytosis as does direct inhibition of myosin. CD47–SIRPα interaction initiates a dephosphorylation cascade directed in part at phosphotyrosine in myosin. A point mutation turns off this motor's contribution to phagocytosis, suggesting that self-recognition inhibits contractile engulfment.
PREDICTING THE REDSHIFT 2 Hα LUMINOSITY FUNCTION USING [O iii] EMISSION LINE GALAXIES

Upcoming space-based surveys such as Euclid and WFIRST-AFTA plan to measure baryonic acoustic oscillations in order to study dark energy. These surveys will use IR slitless grism spectroscopy to measure redshifts of a large number of galaxies over a significant redshift range. In this paper, we use the Wide Field Camera 3 Infrared Spectroscopic Parallel Survey (WISP) to estimate the expected number of Hα emitters observable by these future surveys. WISP is an ongoing Hubble Space Telescope slitless spectroscopic survey, covering the 0.8–1.65 μm wavelength range and allowing the detection of Hα emitters up to z ~ 1.5 and [O iii] emitters to z ~ 2.3. We derive the Hα–[O iii] bivariate line luminosity function (LLF) for WISP galaxies at z ~ 1 using a maximum likelihood estimator that properly accounts for uncertainties in line luminosity measurements and we demonstrate how it can be used to derive the Hα luminosity function by exclusively fitting [O iii] data. Using the z ~ 2 [O iii] LLF and assuming that the relation between Hα and [O iii] luminosity does not change significantly over the redshift range, we predict the Hα number counts at z ~ 2—the upper end of the redshift range of interest for future surveys. For the redshift range 0.7 < z < 2, we expect ~3000 galaxies deg−2 for a flux limit of 3 × 10^(−16) erg s^(−1) cm^(−2) (the proposed depth of the Euclid galaxy redshift survey) and ~20,000 galaxies deg^(−2) for a flux limit of ~10^(−16) erg s^(−1) cm^(−2) (the baseline depth of the WFIRST galaxy redshift survey).
Dynamism, Capital Structure, and Performance in a Sub-Saharan Economy: Extending the Institutional Difference Hypothesis

Extant research examining the capital structure–performance relationship has been undertaken primarily in developed economies. These studies integrate agency theory considerations with the contingency perspective and suggest a positive interaction between sector dynamism, equity, and performance. Our study extends this research stream by examining the capital structure–performance link in a sub-Saharan economy, an underresearched but economically emerging region. Using logic undergirding a substantial stream of institutional theory-based studies that we term the institutional difference hypothesis, we argue that the implications of the capital structure–performance relationship are contingent on the extent of national-level institutional underdevelopment. Taking into account institutional differences between developed economies and those in the sub-Saharan region, we hypothesize a negative interaction between sector dynamism, equity, and firm performance in sub-Sahara. Using longitudinal data from Ghanaia...
Mechanistic Studies on Malate Dehydrogenase from Escherichia coli

Abstract Kinetic studies and chemical modification studies using diethylpyrocarbonate and iodoacetate were performed on malate dehydrogenase isolated from Escherichia coli . Product inhibition experiments indicate that this enzyme follows an ordered Bi Bi kinetic mechanism, similar to other dehydrogenases, while log V / K profiles reveal that one ionizing group with a p K a between 7.8 and 8.7 acts as a general acid/general base in the catalytic mechanism. Log V pro files indicate that malate binds to the correctly protonated form of the enzyme while binding of OAA is pH-independent. Chemical modification experiments implicate an activate site histidine residue is essential for catalytical activity. A primary kinetic isotope effect of 1.44 ± 0.14 on V / K using malate-2-d at pH 9.0 was measured while no isotope effect was observed on V max which is, again, similar to other dehydrogenases. This implies that proton abstraction is partially rate determining under nonsaturating conditions. Within experimental error, small isotope effects were observed on V and V / K (1.219 ± 0.188 and 1.078 ± 0.064, respectively) when NADD was utilized indicating that release of cofactor may be rate limiting.
The Rayleigh-Taylor instability in dusty plasmas

Abstract The Rayleigh-Taylor instability in dusty plasmas is analyzed. The presence of negatively charged dust substantially reduces the range of unstable wave numbers, while the opposite is true for positively charged dust. The charge on the dust grains is assumed to remain constant throughout wave growth. It is shown, on the basis of recent work by Havnes et al. ( Phys. Scr. 45 , 491, 1992) and Melandso et al. ( J. geophys. Res. , in press, 1993), that this assumption is valid only for wave frequencies much smaller (or much larger) than the charging frequency of the dust grains.