cssi/SciSciGPT-SciSciNet huggingface dataset:
Functional properties and developmental regulation of nicotinic acetylcholine receptors on embryonic chicken sympathetic neurons

Measurement of acetylcholine (ACh)-induced currents indicates that the sensitivity of embryonic sympathetic neurons increases following innervation in vivo and in vitro. We have used single-channel recording to assess the contribution of changes in ACh receptor properties to this increase. Early in development (before synaptogenesis), we detect three classes of ACh-activated channels that differ in their conductance and kinetics. Molecular studies indicating a variety of neuronal receptor subunit clones suggest a similar diversity. Later in development (after innervation), changes in functional properties include increases in conductance and apparent mean open time, the addition of a new conductance class, as well as apparent clustering and segregation of channel types. These changes in channel function are compatible with the developmental increase in ACh sensitivity.
Surprising Reaction of Non-Nucleophilic Bases with 1-Hydrosiloles: Addition and Not Deprotonation1

The reaction of 1-R-(Ph4-silole), (R = Ph (1), Me (2), (Ph4-silole = 2,3,4,5-tetraphenyl-1-silacyclopentadiene), with sodium bis(trimethylsilyl)amide in THF yields only nucleophilic substitution products, 1-R-1-(bis(trimethylsilyl)amino)-(Ph4-silole). 1-H-(Ph4-silole) (3) reacts with sodium bis(trimethylsilyl)amide in THF to give the observed anionic intermediate, 1-bis(trimethylsilyl)amino-2-sodio-2,3,4,5-tetraphenyl-1-silacyclopent-3-ene (14), the result of hydride migration of the initially formed pentacoordinate intermediate. Quenching of 14 with methyl iodide gives two geometrical isomers of 1-(bis(trimethylsilyl)amino)-5-methyl-2,3,4,5-tetraphenyl-1-silacyclopent-3-ene (9a,b) in a ratio of 1:1. When a good leaving group (R = Cl, 4) is on the silicon, displacement of the chloride by the bis(trimethylsilyl)amide group takes place, affording 1-(bis(trimethylsilyl)amino)-(Ph4-silole) (10). The substitution products can be explained by a pathway involving pentacoordinate anionic intermediates that underg...
Bicarbonate availability for vocal fold epithelial defense to acidic challenge.

Objectives:Bicarbonate is critical for acid-base tissue homeostasis. In this study we investigated the role of bicarbonate ion transport in vocal fold epithelial defense to acid challenges. Acidic insults to the larynx are common in gastric reflux, carcinogenesis and metastasis, and acute inflammation.Methods:Ion transport was measured in viable porcine vocal fold epithelium. First, 18 vocal folds were exposed to either the carbonic anhydrase antagonist acetazolamide or to vehicle. Second, 32 vocal folds were exposed to either a control buffer or a bicarbonate-free buffer on their luminal or basolateral surface or both. Third, 32 vocal folds were challenged with acid in the presence of bicarbonate-free or control buffer.Results:The vocal fold transepithelial resistance was greater than 300 Ω*cm2, suggesting robust barrier integrity. Ion transport did not change after exposure to acetazolamide (p > 0.05). Exposure to bicarbonate-free buffer did not compromise vocal fold ion transport (p > 0.05). Ion transp...
Advances in the use of high hydrostatic pressure for processing cereal grains and legumes.

On a world scale, cereal grains and legumes are the main source of calories in the human diet. They provide most of the energy needed and about 8% of the proteins and vitamins. Grains usually undergo some type of processing involving heat treatment, which improves digestibility and removes allergens. Recent studies have demonstrated that under optimal conditions, high hydrostatic pressure (HHP), a promising nonthermal technology applied to food products, may inactivate the anti-nutritional factors of grains while preserving food quality and constituents. During HHP treatment, allergenic proteins from rice grains are solubilized, particularly the 7S globulins; while no apparent alteration in color, shape, or size of treated seeds occurs at moderate pressure. The vegetable protein in soybeans (tofu) is usually preserved if refrigerated under vacuum conditions; however, tofu subjected to HHP treatment has been shown to reduce microbial population while increasing protein digestibility. Other constituents of grains such as vitamin A are not significantly affected, while water soluble vitamins (B1, B6, and C) are well retained (85%). Other applications of HHP for cereals include wheat and barley flours, and activity of amylases. A further possibility of creating new textured products from doughs subjected to HHP is being studied as well.
Conserving resources after carotid endarterectomy: Selective use of the intensive care unit

Abstract A retrospective review was undertaken of a random sample ( N = 73) comprising 50% of carotid endarterectomies performed during 1986 to evaluate the necessity of routine postoperative intensive care unit (ICU) admission after carotid endarterectomy. Severity of illness was determined with use of the Acute Physiology Score of the APACHE II system. The Therapeutic Index Scoring System was used to quantify postoperative services used. Postoperative morbidity was analyzed. Financial impact was extrapolated with use of 1990 billing data. Length of ICU stay was 24.5 hours. Only 13 of 73 patients (18%) required ICU services. In 10 (77%) of these patients therapy was initiated in the recovery room and discontinued in six patients within 3 hours of ICU admission. Only two patients required ICU services for 16 hours after surgery. The mean Acute Physiology Score was low (4.96) and could not identify patients who required unique ICU services. Neurologic deficits were seen in five patients (6.9%). In three cases deficits were recognized in the recovery room; deficits developed in two patients after discharge from the ICU. Observation in the recovery room with transfer of stable patients would have eliminated ICU admission in 60 patients (82%). In 1990 the incremental ICU charge was $720/patient day. This represents 12.5% of the hospital charges for carotid endarterectomy. The ICU is an expensive and highly used hospital resource. Only a few patients need unique ICU services after carotid endarterectomy, and this is usually apparent within 2 hours of surgery. Prolonged recovery room observation or use of intermediate care units can avoid ICU admission for most patients undergoing carotid endarterectomy thereby conserving this precious hospital resource. (J VASC SURG 1991;14:796-802.)
Early mechanical restraint improves border zone function during infarction induced ventricular remodeling

VAD usage and the necessity for device change-out(DCO). Between January 1, 2000 and December 31, 2002, 58 patients underwent implantation of the Heartmate LVAD. 8 implants were a part of the REMATCH trial and 50 were bridge to transplantation. 9 patients required DCO for device failure. 4 patients required a second DCO. Inflow valve dysfunction was the etiology in 7 devices, motor malfunction in 4 devices, and infection in 2. The 30 day mortality was 8.6% (5/58) after first implant, 22.2% (2/9) after first DCO, and 0% (0/4) after second DCO. The mean implant to failure time was 332 days (range: 15–632 days). Mean time to failure of the inflow valve was 408 days (range: 240–632). Mean time to failure of motor malfunction was 285 days (range: 15–439). One patient that had change-out for infection died within 30 days and the second survived to successful transplantation. Of 50 bridge to transplant patients, the longest implant free of device failure was 681days. 6 of the 8 REMATCH patients were 30-day survivors and all 6 had DCOs. Three had a second DCO. All 6 were long-term survivors. Based on clinical input, the manufacturer made technological changes, which greatly enhanced the durability. All 7 inflow valve failures were in the original VE series, with no such failures with the newer XVE series. Conclusion: Device dysfunction sufficient to cause DCO may occur with prolonged periods of VAD support. The more successful the clinical results become, the more likely it will be that the ultimate durability of any device will be reached. Device modifications give promise to greater device longevity and modifications of initial surgical techniques may assist in the ease of subsequent device change-out procedures.
Citizenship and social justice in urban science education

This article describes, and then applies a newly developed framework for classroom citizenship as an entry point into addressing social justice issues in urban science classrooms. The author provides in‐depth descriptions of cogenerative dialogues, coteaching, and cosmopolitanism (3Cs), and presents this triad of tools as an approach to research/practice that addresses full participation of youth in an urban physics classroom. By describing the 3Cs, in an urban classroom, the author presents under‐discussed issues that inhibit urban youth from fully participating in urban science classrooms, as an inhibitor to social justice within the classroom.
Optimal broadcasting in hypercubes with link faults using limited global information

Abstract We propose a fault-tolerant broadcasting algorithm for hypercubes with link faults. This algorithm is based on an extended spanning binomial tree structure that still keeps the simplicity of conventional binomial-tree-based broadcasting. In addition, it is optimal in the sense that exactly n steps are required to complete a broadcast in an n-dimensional injured hypercube with up to n − 2 faulty links. We also show that n − 2 is the maximum number of faulty links that can be tolerated in any optimal broadcast scheme in an n-dimensional hypercube. To implement the proposed algorithm each node keeps information of nearby faulty links in terms of addresses for those faulty adjacent m-subcubes that contain at least m − 1 faulty links.
Outcome in children with fetal mild ventriculomegaly : a case series

Mild enlargement of the lateral ventricles is associated with schizophrenia and other neurodevelopmental disorders. While it has been hypothesized that ventricle abnormalities associated with neurodevelopmental disorders arise during fetal brain development, there is little direct evidence to support this hypothesis. Using ultrasound, it is possible to image the fetal ventricles in utero. Fetal mild ventriculomegaly (MVM) has been associated with developmental delays in early childhood, though longer-term neurodevelopmental outcome has not been studied. Follow-up of five children (aged 4--9 years) with mild enlargement of the lateral ventricles on prenatal ultrasound and two unaffected co-twins is reported: one child had attention deficit hyperactivity disorder (ADHD), one had autism, and two had evidence of learning disorders. These cases suggest that the mild enlargement of the lateral ventricles associated with these neurodevelopmental disorders arises during fetal brain development and can be detected with prenatal ultrasound. In addition, the presence of mildly enlarged, asymmetric ventricles in two children on prenatal ultrasound and on follow-up MRI at age 6 years indicates that ventricle structure present in utero can persist well into childhood brain development. The study of fetal ventricle development with ultrasound may provide important insights into neurodevelopmental disorders and allow the identification of children at high risk.
Laminar Fluid Diffusion Interface Preconditioning of Serum and Urine for Reagent-Free Infrared Clinical Analysis and Diagnostics

A number of reagent-free infrared spectroscopic diagnostic and analytical methods have been established previously making use of dry biofluid films. For example, this approach has successfully measured high concentration analytes of serum and urine. However, a number of low concentration diagnostically relevant analytes presently elude detection by infrared spectroscopy. This is due in part to their relatively low concentration and in part to spectral interference by other strongly absorbing constituents. The applicability of the technique would be broadened substantially if it were possible to concentrate and separate lower concentration analytes, e. g., serum creatinine and urine proteins, from the obscuring presence of relatively high concentration compounds. One possible means to achieve this is through microfluidic sample preconditioning based on laminar fluid diffusion interfaces. The objective of this study was therefore to qualitatively assess the performance of this technology in preferentially separating certain serum and urine analytes of clinical interest that presently lie just below the threshold of detection by infrared spectroscopy. Observations from simulated and genuine urine and serum samples strongly suggest that this process should improve existing accuracy and extend the range of detectable analytes.
SHORT‐TERM BONUS PLAN ADOPTION AND STOCK MARKET PERFORMANCE—PROXY AND INDUSTRY EFFECTS: A NOTE

This note extends previous studies and further examines the market reaction to short-term executive compensation plan introduction by using a larger sample and controling for proxy and industry effects. Results indicate significantly positive abnormal returns not due to proxy or industry effects in the four months before adoption and the month of adoption. The price adjustment is not instantaneous. Firms adopting short-term compensation plans also experience significantly positive abnormal returns ten months after announcement, associated with positive unexpected earnings in that month.
Chronic graft-versus-host disease and pulmonary function.

Pulmonary complications are a major cause of morbidity and mortality in bone marrow transplant recipients. Earlier series, consisting mainly of adults, have shown evidence of obstructive changes of pulmonary functions in association with chronic graft-versus-host disease (CGVHD). We longitudinally evaluated spirometry in 46 patients who received bone marrow transplants as children or as young adults to determine whether they had similar abnormalities. Group mean FEV1/FVC, and percent predicted FVC, FEV1, and FEF25-75 values did not demonstrate obstructive changes in association with CGVHD in this patient population. Our findings suggest that younger patients with CGVHD, as a group, may fare better than older bone marrow transplant recipients with CGVHD. However, due to small sample sizes, it cannot be conclusively stated that the pulmonary function parameters analyzed do not differ in the two patient groups. © 1992 Wiley-Liss, Inc.
Eliminating Asthma Disparities: Introduction to the Chicago Story

The problem of inner-city asthma, as studied in Chicago, IL, is introduced. Chicago has a high incidence of asthma, but prevalence, morbidity, and mortality rates vary by neighborhood and are highest in neighborhoods with the lowest socioeconomic status. Efforts in Chicago to mitigate these gaps have been extraordinary, but data suggest that there are challenges to improvement in removing disparities.
Pregnancy at or beyond age 40 years is associated with an increased risk of fetal death and other adverse outcomes.

Objective The objective of the study was to determine the frequency of fetal death in women 40 years of age or older (AMA). Study Design Retrospective study of all singleton pregnancies delivered at our institution between the years 1989 and 2004 was performed. The primary outcome measure was the risk of fetal death at various gestational ages. We also investigated the frequency of maternal comorbidities, preterm delivery (PTD), and low and very low birth weights (LBW, VLBW). Results Data were available for 126,402 singleton deliveries. AMA was an independent risk factor for fetal death at 28-31 weeks (adjusted odds ratio [AOR] 2.93, 95% confidence interval [CI] 1.76-4.92), 32-36 (AOR 1.73, 95% CI 1.05-2.83), 37-39 weeks (AOR 1.63, 95% CI 0.97-2.75), and 40-41 weeks (AOR 2.28, 95% CI 1.18-4.4). AMA was associated with increased rates of PTD, LBW, and VLBW. Conclusion AMA is associated with an increased rate of fetal death and other adverse obstetrical outcomes. Antepartum fetal surveillance may be warranted in these women.
Eye on the Gemba: Using Student-Created Videos and the Revised Bloom's Taxonomy to Teach Lean Management

Developing exercises that lead students to use higher order thinking skills is a challenge for faculty in any discipline. An excellent way to approach this problem is to use the Revised Bloom's Taxonomy as a guide. In the taxonomy, the highest level of learning is to create. The author describes an assignment that builds on the use of lecture, tests, and games represented in different levels in the taxonomy by giving students the opportunity to develop, revise, and create videos illustrating lean terms. This enables students to understand these terms better, which will help them when they are in the gemba, or workplace, solving real problems.
Beliefs about expectations moderate the influence of expectations on pain perception.

Background Expectations congruently influence, or bias, pain perception. Recent social psychological research reveals that individuals differ in the extent to which they believe in expectation biases and that individuals who believe in expectation biases may adjust for this bias in their perceptions and reactions. That is, idiosyncratic beliefs about expectations can moderate the influence of expectations on experience.
A self-contained system for observing and quantifying the behavior of Atlantic cod, Gadus morhua, in an offshore aquaculture cage

Abstract A self-contained data collection system is described that was used to investigate the behavior of Atlantic cod ( Gadus morhua ) in an offshore net pen (Sea Station 3000) located 13 km off the coast of New Hampshire, USA. The entire system was housed inside a modified U.S. Coast Guard (USCG) navigational buoy that was retrofitted for this purpose. Power was provided by a combination of eight 12 V batteries, two solar panels and a wind generator. The behavior of the population of cod as a whole, during daylight hours, was monitored using four waterproof cameras connected to a four channel digital video recorder. The behavior of 4–12 individual fish implanted with ultrasonic transmitters was continuously recorded, during each of four study periods, using a HTI model 291 ultrasonic telemetry system. Laboratory studies showed no influence of transmitter implantation on swimming or feeding behavior. Transmitters were programmed to “ping” at intervals between 1.7 and 3.3 s and they typically lasted for about one month. The system successfully detected and plotted 84.9 ± 6.0% of transmissions, resulting in an average of 1283.4 ± 252.5 positional fixes for each animal, during each hour of the study. This preliminary evaluation of cod behavior in a net pen demonstrated that they are diurnally active and have a tendency to mill about, rather than school. Cod predominately used the lower half of the cage, except when rising to the feeding area during periods when feed was delivered. The system that was developed proved to be ideal for investigating the behavior of fish within a net pen, and it can be used by both inshore and offshore farms to gather behavioral data that can lead to improvements in the efficiency of aquaculture operations.
On Stoffregen's Definition of Affordances

Stoffregen (2003) has proposed a formal definition of affordances as emergent or relational properties of animal-environment systems. This definition contrasts with Turvey's (1992) formal definition of affordances as properties of the environment. In this commentary, my purpose is not to take sides on this issue but instead to bring to light what I believe to be a crucial flaw in Stoffregen's definition. Specifically, I show that Stoffregen's definition places no constraint on which relational or emergent properties legitimately deserve to be counted as affordances, thus allowing any relational property that can be predicated of an animal-environment system to be considered as an affordance. As such, Stoffregen's definition lacks any substantive linkage to the "opportunity for action" notion that has accounted for the scientific utility of the concept to date, a linkage I suggest should be preserved in any definition of affordances.
Liquid-phase sintered iron aluminide-ceramic composites

Abstract Iron aluminide intermetallics, which exhibit excellent oxidation and sulfidation resistance, were found to be suitable as the matrix phase in metal matrix composites, or the binder in hard metals (or cermets). In particular, ceramics such as TiB2, ZrB2, TiC and WC could all be liquid-phase sintered with an Fe-40 at% Al iron aluminide. The processing and properties of such iron aluminide composites were assessed. Density, hardness, bend strength, and fracture toughness data are presented. Nearly complete densification was achieved for ceramic volume fractions up to 60%. For iron aluminide-tungsten carbide composites containing 60 vol% WC, room temperature three-point bend strengths and fracture toughnesses reached 1460 MPa and 20 MPa m 1 2 , respectively. Consistent with the high fracture toughness values, the fracture surfaces showed evidence for ductile deformation of the iron aluminide binder.
Vertical column electrophoresis in sephadex G-200.

Abstract A method for electrophoretic separation in a vertical column packed with Sephadex G-200 superfine media is described. Collection of electrophoretically separated components is accomplished by converting the column to an eluting system after electrophoresis. The method has been used successfully to isolate human galactose-1-phosphate uridyltransferase. The application of a human serum sample was used to demonstrate the fractionation potential of the method.
Plastic deformation modeling of AL-6XN stainless steel at low and high strain rates and temperatures using a combination of bcc and fcc mechanisms of metals

Abstract Combination of physically based constitutive models for body centered cubic (bcc) and face centered cubic (fcc) metals developed recently by the authors [Voyiadjis, G.Z., Abed, F.H., 2005. Microstructural based models for bcc and fcc metals with temperature and strain rate dependency. Mech. Mater. 37, 355–378] are used in modeling the plastic deformation of AL-6XN stainless steel over a wide range of strain rates between 0.001 and 8300 s−1 at temperatures from 77 to 1000 K. The concept of thermal activation analysis as well as the dislocation interaction mechanism is used in developing the plastic flow model for both the isothermal and adiabatic plastic deformation. In addition, the experimental observations of AL-6XN conducted by Nemat-Nasser et al. [Nemat-Nasser, S., Guo, W., Kihl, D., 2001. Thermomechanical response of AL-6XN stainless steel over a wide range of strain rates and temperatures, J. Mech. Phys. Solids 49, 1823–1846] are utilized in understanding the underlying deformation mechanisms. The plastic flow is considered in the range of temperatures and strain rates where diffusion and creep are not dominant, i.e., the plastic deformation is attributed to the motion of dislocations only. The modeling of the true stress–true strain curves for AL-6XN stainless steel is achieved using the classical secant modulus for the case of unidirectional deformation. The model parameters are obtained using the experimental results of three strain rates (0.001, 0.1, and 3500 s−1). Good agreement is obtained between the experimental results and the model predictions. Moreover, the independency of the present model to the experiments used in the modeling is verified by comparing the theoretical results to an independent set of experimental data at the strain rate of 8300 s−1 and various initial temperatures. Good correlation is observed between the model predictions and the experimental observations.
Antimicrobial prophylaxis in pediatric critical care

Patients admitted to the pediatric intensive care unit are at increased risk of developing infections that may exacerbate their already labile conditions. Different strategies are used to prevent infection in patients and their contacts in this setting. They include the implementation of infection control policies and the use of immunotherapy and prophylactic antimicrobials. The following is a review of the different chemotherapeutic approaches established or suggested to prevent infection in these highly susceptible hosts. The conditions in which these interventions may be used consist of surgical wound infections, solid organ transplantation, cardiac disease suitable for endocarditis prophylaxis, and pathogen-or host-specific situations in which prophylaxis may be required. Chemoprophylactic strategies used to prevent infection in contacts, including hospital personnel, in situations in which the offending organism is highly transmissible or virulent also are described.
The problem of a self-gravitating scalar field

In this paper we begin the study of the global initial value problem for Einstein's equations in the spherically symmetric case with a massless scalar field as the material model. We reduce the problem to a single nonlinear evolution equation. Taking as initial hypersurface a future light cone with vertex at the center of symmetry, we prove, the local, in retarded time, existence and global uniqueness of classical solutions. We also prove that if the initial data is sufficiently small there exists a global classical solution which disperses in the infinite future.
Identifying hearing loss: parents' needs.

Universal neonatal hearing screening programs are being established across the country at a rapidly accelerating rate, prompted by professional endorsement, legislated mandates, and available techn...
Magnetically targeted delivery of therapeutic agents to injured blood vessels for prevention of in-stent restenosis.

Magnetic guidance is a physical targeting strategy with the potential to improve the safety and efficacy of a variety of therapeutic agents — including small-molecule pharmaceuticals, proteins, gene vectors, and cells — by enabling their site-specific delivery. The application of magnetic targeting for in-stent restenosis can address the need for safer and more efficient treatment strategies. However, its translation to humans may not be possible without revising the traditional magnetic targeting scheme, which is limited by its inability to selectively guide therapeutic agents to deep localized targets. An alternative two-source strategy can be realized through the use of uniform, deep-penetrating magnetic fields in conjunction with vascular stents included as part of the magnetic setup and the platform for targeted delivery to injured arteries. Studies showing the feasibility of this novel targeting strategy in in-stent restenosis models and considerations in the design of carrier formulations for magnetically guided antirestenotic therapy are discussed in this review.
Cyclic Nucleotide Phosphodiesterase: High Activity in a Mammalian Photoreceptor

Purified outer segments of bovine rods exhibit phosphodiesterase activity against adenosine and guanosine cyclic 3',5'-monophosphates (cyclic AMP and cyclic GMP). The enzyme hydrolyzed cyclic GMP more rapidly than cyclic AMP at low substrate concentrations. The presence of high phosphodiesterase activity in this highly specialized organelle suggests that this enzyme may function in control of cyclic nucleotide concentration during visual excitation or adaptation.
Radioactive hazard of potable water in Virginia and Maryland

Only a few studies have examined instances of prolonged exposure to radionuclide concentrations found in natural settings. Radium in domestic water in Florida counties has been correlated with a higher than normal incidence of leukemia. A similar study in Iowa towns reported on a correlation between radium and increases in lung, bladder and breast cancer. Radium and radon in domestic water has been correlated with the development of lung cancer in a study of several Texas counties. A correlation has been found between radon in home water supplies in Maine and the incidence of lung cancer. Starting in the winter of 1986-87, the Center of Basic and Applied Science conducted a study of indoor radon and soil radon. Most of the study homes are in Fairfax County in northern Virginia, and the immediately adjacent Montgomery County in southern Maryland. Approximately 650 homeowners agreed to participate in the radon-in-water study. The study group now includes approximately 1,400 people, over 1,000 of whom have consumed their present water supply for 5 or more years, and over 700 of whom have consumed this water for 10 or more years.
The electron temperature and optical emission structure of the central component of CTB 80

Optical spectra on the central component of the galactic supernova remnant CTB 80 are presented. Long slit CCD spectra reveal relative line-intensity variations among individual filaments, the presence of Balmer-dominated emission in the core's east and west optical lobes, and no radial velocities in excess of 300 km/s. Aperture spectrophotometry of the temperature-sensitive forbiddden O III lines suggests Te = 25,000 K, thus favoring a shock-heated interpretation for the remnant's optical core emission. These results indicate that fundamental differences exist betweem the optical emission of CTB 80's central core component and the Crab Nebula, despite similarities in these remnants' radio and X-ray properties. The optical emission from CTB 80's core is likely to be a direct result of the interaction of an active pulsar with its adjacent partially neutral interstellar medium. The size of CTB 80's outer structure and the absence of either high velocity or enhanced abundances in the region local to CTB 80's pulsar argue for a considerably larger age for CTB 80 than the Crab Nebula's 1000 yr. A qualitative picture for CTB 80 that can plausibly explain many of the core's properties is proposed.
Changing Meanings of Electoral Marginality in U.S. House Elections, 1824-1978

Gary Jacobson (1987a, 1987b) has suggested that increased vote proportions for incumbent House candidates during the 1960s and 1970s have not resulted in greater electoral safety, primarily because of greater observed volatility in interelection vote swings occurring during the same era. Using data on House elections from 1824 to 1978, we find that both "marginal" and "safe" incumbents are much more vulnerable to electoral defeat during the 19th century than during the 20th century. This pattern seems to be explained by greater homogeneity of interelection vote swings during the 20th century. Overall, our results lend strong support to Jacobson's assertion that the meaning of electoral marginality varies substantially over time.
Understanding the Impact of Direct-to-Consumer (DTC) Pharmaceutical Advertising on Patient-Physician Interactions: Adding the Web to the Mix

As a growing number of people go on-line for health- and drug-related information, pharmaceutical companies devote significant resources to direct-to-consumer (DTC) promotions on the Web. Little is known about how DTC advertising of prescription drugs on the Web impacts patient—physician interactions, however. This study identified and investigated the influence of credibility perception of the Web for information related to prescription drugs, overall attitudes toward DTC advertising, and age on consumers' inquiries and requests for prescription drugs advertised on the Web. Findings of this study suggest that Web credibility and attitudes toward DTC advertising in general exert significant influence on consumer response to DTC advertising on the Web in the form of patient—physician interactions.
Investigating the Epidemiology of Repeat Chlamydia trachomatis Detection after Treatment by Using C. trachomatis OmpA Genotyping

Repeat Chlamydia trachomatis detection frequently occurs within months after C. trachomatis infection treatment. The origins of such infection (persistence versus reinfection from untreated or new partners) are varied and difficult to determine. C. trachomatis strains can be differentiated by sequencing the ompA gene encoding the outer membrane protein A (OmpA). We used OmpA genotyping to investigate the epidemiology of repeat C. trachomatis detection after treatment in C. trachomatis-infected subjects seen at a sexually transmitted diseases clinic. Subjects were enrolled, tested for C. trachomatis, treated with azithromycin, and scheduled for a 6-month follow-up for repeat C. trachomatis testing. OmpA genotyping was performed on C. trachomatis-positive urogenital specimens obtained from patients at enrollment and follow-up. The enrollment visit OmpA genotypes for C. trachomatis were determined for 162 subjects (92% female, 94% African American). C. trachomatis was detected at follow-up in 39 subjects (24%). The OmpA genotype distribution at enrollment did not differ in those with versus those without repeat C. trachomatis detection. Of the 35 subjects with C. trachomatis strains genotyped at enrollment and follow-up, 7 (20%) had the same ompA sequence at both visits, while 28 (80%) had discordant sequences. A new sexual partner was reported more often in subjects with discordant C. trachomatis strains than in those with concordant strains (13 [46%] versus 1 [14%]; P = 0.195). Half of the subjects with discordant C. trachomatis strains who reported sexual activity since treatment denied a new sexual partner; 62% of these subjects reported that their partner was treated. Our study demonstrates that most repeat C. trachomatis detections after treatment were new infections with a different C. trachomatis strain rather than reinfection with the same strain. OmpA genotyping can be a useful tool in understanding the origins of repeat C. trachomatis detection after treatment.
Experiments on Simulated Circumstellar Clusters

Solid grains in a gas cloud ejected from a star condense in a hot gaseous medium with all elements present in their cosmic abundances. A study of this phenomena requires knowledge of the initial clusters that form from a multielement refractory system. Experiments on SiO, Mg + SiO and Fe + SiO clusters in a nitrogen matrix have been performed. Much of the results for the first two systems have been reported. These will be summarized and the iron silicate experiments described. A flow system with a quadrupole mass spectrometer detector has been built to study the temperature dependence of clusters in the gas phase. The systems to be studied are various combinations of Si, O, Mg, Fe and ultimately Ca and C. These six elements constitute the major fraction of refractory cosmic species.
The Mechanisms of RNA SHAPE Chemistry

The biological functions of RNA are ultimately governed by the local environment at each nucleotide. Selective 2′-hydroxyl acylation analyzed by primer extension (SHAPE) chemistry is a powerful approach for measuring nucleotide structure and dynamics in diverse biological environments. SHAPE reagents acylate the 2′-hydroxyl group at flexible nucleotides because unconstrained nucleotides preferentially sample rare conformations that enhance the nucleophilicity of the 2′-hydroxyl. The critical corollary is that some constrained nucleotides must be poised for efficient reaction at the 2′-hydroxyl group. To identify such nucleotides, we performed SHAPE on intact crystals of the Escherichia coli ribosome, monitored the reactivity of 1490 nucleotides in 16S rRNA, and examined those nucleotides that were hyper-reactive toward SHAPE and had well-defined crystallographic conformations. Analysis of these conformations revealed that 2′-hydroxyl reactivity is broadly facilitated by general base catalysis involving mu...
Water Wave Pressure on Horizontal Plate

Simple rules are developed to estimate the maximum uplift pressures induced on the underside of a flat plate by various types of incident waves. Theoretical prediction techniques are provided for both the slow-rise pressure component and the fast-rise pressure component (impact) for different incident waves: standing waves, regular progressive waves, and dispersive waves, all in constant water depth. Laboratory experiments were conducted in a dispersive wave basin partially to check the validity of prediction techniques and partially to provide additional information so that the prediction techniques can be extended empirically to cover the more complicated but more practical situation of a plate in shoaling water. The fast-rise pressure should be of engineering concern not only because the magnitude of its peak is enormous but also because the magnitude of the corresponding impulse is significant. The slow-rise pressure component was found to range from one to two times the hydrostatic pressure.
p16 Modulates VEGF Expression via Its Interaction With HIF-1α in Breast Cancer Cells

The degree of tumor progression (such as growth, angiogenesis, and metastasis) directly correlates with the expression of vascular endothelial growth factor (VEGF), but inversely correlates with the expression of tumor-suppressor gene p16, therefore we examined whether the restoration of p16 in breast cancer cells would modulate VEGF expression. Adenoviral-mediated p16 expression downregulated VEGF gene expression in breast cancer cells, and inhibited breast cancer cell-induced angiogenesis by a dorsal air sac model in mice. Moreover, p16 appears to form a complex with HIF-1a, the transcription factor for the VEGF gene promoter. Taken together, the binding between p16 and HIF-1a protein may alter HIF-1a's ability to transactivate VEGF expression.
Characteristics of InGaN light-emitting diodes on GaN substrates with low threading dislocation densities

InGaN light-emitting diodes (LEDs) on GaN substrates with low threading dislocation densities (TDDs) were fabricated, and the characteristics of the LEDs were compared with those on sapphire substrates. LEDs with 3 nm-thick-quantum-wells (QWs) grown on GaN as well as on sapphire substrates showed a decrease of the external quantum efficiency (EQE) with increasing forward current, indicating that carrier localization is in play in both cases. The decrease in the EQE was, however, suppressed in LEDs grown on GaN substrates by adopting thicker QWs. The LED with 5 nm-thick-QWs on GaN substrate mounted p-side down and molded with epoxy showed EQE as high as 26% at 125 A/cm 2 . Cathodo luminescence (CL) observations revealed the formation of dark areas related to TDDs, and the dark areas deteriorated the EQE of the LED on the sapphire substrate.
The Localization and Mobility of MSH2 in Cells Undergoing Neoplastic Transformation

Genome instability is an underlying factor of all cancers. Defects in DNA repair mechanisms contribute significantly to this factor. Recent reports indicate the mechanical properties of cells change as they advance through different stages of neoplastic transformation. The main goal of this study is to investigate how changes in the intracellular environment and changes in DNA repair protein distribution are altered in cells undergoing neoplastic transformation. For this study we have chosen to use human mammary epithelial (HME) cells from the Weinberg line. Lipofection was used to transiently transfect enhanced green fluorescent protein (egfp) fusions to MSH2 mismatch repair proteins. We have measured the localization and diffusion of these fusions using fluorescence recovery after photobleaching (FRAP) and raster image correlation spectroscopy (RICS) on live cells maintained under appropriate environmental conditions. We have tested normal, immortal, and tumorigenic cells in this study. The acquired data was analyzed using custom written Matlab programs as well as commercially available software. Preliminary results show localization of the fusions to the nucleolus in all cell types tested. The surrounding nucleus generally has the weakest localization signal. We have also observed smaller diffusion coefficients in the nucleus of tumorigenic cells compared to normal cells. This work is supported by NSF Materials and Surface Engineering grant CMMI-1152781.
Assessment of diffusion and perfusion deficits in patients with small subcortical ischemia

BACKGROUND AND PURPOSE: Using perfusion- and diffusion-weighted MR imaging in acute ischemic stroke of the middle cerebral artery (MCA), previous studies have shown a typical pathophysiologic pattern that is characterized by a perfusion deficit larger than the diffusion lesion (mismatch), with the final lesion usually comprising the initial diffusion lesion (core) plus parts of the initial mismatch area. Little is known about underlying pathophysiology in small ischemic stroke. In this study, we used perfusion- and diffusion-weighted MR imaging to investigate the underlying pathophysiology of small subcortical ischemia. METHODS: Six consecutive patients (age range, 42–76 years) with small subcortical ischemia were examined by using a 1.5-T MR system 2–5, 22–55, and 144–392 hours after the onset of symptoms. T2-weighted, diffusion-weighted imaging at b=0 s/mm 2 and b=1000 s/mm 2 , and bolus-track perfusion-weighted imaging were performed. Lesion sizes were determined on the basis of T2-weighted findings as well as those of apparent diffusion coefficient (ADC) maps and CBF. RESULTS: In every patient, the initial CBF lesion was smaller than the initial ADC lesion. Both the CBF lesion and the ADC lesion increased in size from first to second examination. In all instances, however, the CBF lesion remained smaller than the ADC lesion. The CBF lesion observed during the acute phase and the one seen on the following days were both smaller than the final T2 lesion. CONCLUSION: Our data suggest that in contrast to previous findings in MCA ischemia in small subcortical infarcts tissue damage may spread beyond the area of the initial perfusion disturbance. In light of the small number of patients, further studies will have to address the relevance of this observation.
Review of the toxicity of multifunctional acrylates

Multifunctional acrylates and methacrylates (MFA) represent a class of materials with considerable chemical reactivity that are used in many applications with opportunity for contact exposure. They represent appreciable eye and skin contact hazards, and several members of the class may be absorbed from skin to cause systemic effects. A number of MFAs have been identified as sensitizers. While the acute toxicity of MFAs is certain, the effects of repeated or chronic exposure are less clear. Data are presented that suggest that MFAs are not appreciable fetotoxic or teratogenic hazards and do not elicit a strong carcinogenic response following chronic dermal exposure. The use of these data for product safety purposes and research needs is discussed.
The effects of ankle bracing on motion of the knee and the hip joint during trunk rotation tasks

Background. The use of prophylactic ankle braces is common during athletic activities since the ankle is one of the most commonly injured joints. Past studies have focused on the effects of ankle braces on ankle movement restriction, preventing injuries, proprioception, balance and athletic performance. However, the influence of ankle restriction on other joints has not been studied. The constraint of ankle movement may lead to an increased loading on the knee joint, which could be a potential risk of knee injuries during athletic activities. The primary goal of the current study was to determine quantitatively the effect of an ankle brace on the knee axial rotation during two different trunk turning tasks. Methods. Ten healthy subjects performed trunk turning movements while standing on one leg: turning sideways to catch a ball and turning sideways to touch a target with the shoulder. The tasks were performed with and without an ankle brace worn on the supporting leg. The trunk axial rotation in reference to the floor and three dimensional joint angular motions of the ankle, knee and hip were determined. Findings. The use of an ankle brace resulted in reduced trunk axial rotation during the ball catching tasks, and increased knee axial rotation during the target touching tasks. Interpretation. The results of this study showed that the effect of the ankle brace on the knee axial rotation depended on the context of the tasks performed. Under situations that required forceful trunk turning movement while standing on a single leg, the ankle braces may cause an increase in the knee axial rotation indicating higher risk of knee injury. 2004 Elsevier Ltd. All rights reserved.
NIH Budget Grows, but not R01 Success Rates

The principal source of U.S. funding for biomedical research has been the National Institutes of Health (NIH) and its main mechanism, the investigator-initiated, competitive, peer-reviewed R01 project grant. Data for funding such grants in fiscal year 2000 ([1][1]), just prepared by NIH for the
Static and Dynamic Effects of Health Policy: Evidence from the Vaccine Industry

Public policies designed to increase utilization of existing technologies may also affect incentives to develop new technologies. This paper investigates this phenomenon by examining policies designed to increase usage of preexisting vaccines. I find that these policies were associated with a 2.5-fold increase in clinical trials for new vaccines. For several diseases, the induced innovation is socially wasteful, though small in magnitude. In one case, however, the "dynamic" social welfare benefits from induced innovation exceed the policies' "static" benefits from increasing vaccination with existing technology. These findings underscore the importance of including technological progress in economic analysis of public policy.
Correlation of Diet, Other Chewing Activities and Periodontal Disease in North American Client-Owned Dogs:

In 1350 client-owned dogs in North America, the association of calculus, gingival inflammation and periodontal bone loss with diet (dry food only, or other than dry food only), and with access to other chewing materials was analyzed. There were few apparent differences seen in dogs fed dry food only compared with those fed other than dry food only. There was progressively less accumulation of calculus, less gingival inflammation and less periodontal bone loss in dogs that were given access to more types of chewing materials (rawhides, bones, biscuits, chew toys) compared with dogs given access to fewer or no chewing materials. When the effects of individual chewing materials were analyzed, access to rawhides overall had the greatest apparent periodontal protective effect, and this effect was more apparent in dogs fed dry food only compared with those fed other than dry food only.
Comentario a "Tasa de rendimiento de la educación, productividad y nivel de ingreso de la pequeña industria de Jorge Iván González.

Muestra como bajo ciertas condiciones del mercado las unidades si estan maximizando sus ganancias, esto no necesariamente significa un optimo social y tiene ademas ciertas implicaciones de politica con respecto a la pequena industria las cuales coinciden con algu
Nebraska Choice of Law: A Synthesis

Although U.S. choice-of-law (or conflict-of-laws) principles have been notoriously unstable and have led to unpredictable results, matters may be settling down to the point where conflicts rules or near-rules are emerging. To be sure, they are narrower rules than the ones that were employed by U.S. courts before the revolution began in the 1960's, but their emergence may foster increased predictability and stability in litigation. Nebraska makes for an interesting case study as much of its new conflicts jurisprudence can be distilled into rules or near-rules.