cssi/SciSciGPT-SciSciNet huggingface dataset:
Drug-induced depression of gamma efferent activity—II. Central action of nicotine☆

Abstract Nicotine, which produces a generalized depression of spontaneous γ efferent activity by reflex action in the cat under chloralose-urethane anesthesia, has now been shown to be capable of affecting γ discharge also by a central action. The evidence for this central action is threefold. First, there is a hexamethonium-resistent component of nicotine-induced γ depression after intravenous injection of doses above 80 μg/kg, whereas the γ depressant effect of sebacylcholine, a peripherally acting nicotinic stimulant, could always be blocked by hexamethonium. Second, nicotine elicits γ depression when injected into the lateral ventricle of the brain in amounts of 1–5 μg/kg. Third, this effect, elicited from a yet unspecified region bordering the ventricular space, yields to blockade by the centrally acting nicotine antagonist mecamylamine given by either route, but persists in presence of peripheral nicotine block induced by hexamethonium. The γ depression ensuing upon intracerebroventricular injection resembled that following intravenous injection of nicotine. It was often preceded by brief acceleration and occurred bilaterally in extensor as well as flexor fibers. With the fusimotor innervation intact, spindle afferent discharge paralleled the changes in γ activity. Both the dynamic and static responses of group Ia units were reduced during the γ depression. The central site of the γ depressant effect of nicotine must differ from that of chlorpromazine, since chlorpromazine still depressed γ firing when the nicotine effect was abolished by mecamylamine. Both nicotinic and muscarinic cholinergic antagonists left spontaneous γ activity unaffected, indicating that the neurocircuits sustaining this activity have no cholinergic neurons. Cholinergic mechanisms, on the other hand, may be involved in the central control of γ discharge, as the centrally induced γ depression after nicotine injection does suggest.
A Class of Static and Dynamic Hierarchical Interconnection Networks

A TCN is a hierarchical interconnection network where isomorphic clusters are connected using a complete graph at the highest level of hierarchy. We extend the concept of TCN to the dynamic domain and reduce the hardware complexity in the static domain. The resulting networks outperform both its non-hierarchical and hierarchical counterparts, while improving on the congestion and fault-tolerance characteristics of the latter; they also have optimal connectivity, high bisection width, low degree, cost and diameter, and low average distance under both uniform and non-uniform traffic. For instance, with dynamic clusters we obtain the same delay as the corresponding non hierarchical multistage network at 1/2 the cost; while the maximum and average delays are typically 2/3 and 3/4 of those in a comparable HMIN, at approximately the same cost. In the static case, using hypercube clusters, the degree, diameter and cost are approximately 1/2, 3/4 and 3/8 of the same parameters in a comparable size hypercube; while the diameter and average distance are typically 1/2 and 3/4 of those in traditional HINs. In case of mesh clusters, the diameter and cost are reduced even further, by an amount proportional to their square root.
Correspondence between rates of host plant consumption and responses to the Acalymma vittatum male-produced aggregation pheromone

Abstract In field studies, wind-directed traps were used to investigate the resource-based properties of the male-produced aggregation pheromone of Acalymma vittatum (F.) (Coleoptera: Chrysomelidae). Responses to early season overwintered field-collected male A. vittatum without food were compared with those feeding on pollen, and in turn these were compared with those feeding on cucurbit seedlings. These comparisons were modelled after transitions as they would occur at the initiation of A. vittatum host plant colonization. In another experiment, colony-reared male A. vittatum that had been fed only near isogenic lines of potted cucumber (Cucumis sativus) seedlings that either lacked or contained cucurbitacin were placed as bait in the traps. Using the inverse relationship, which is understood for A. vittatum, between previous exposure and the phagostimulant response to cucurbitacin, rates of foliage consumption could be manipulated. The interaction between relative rates of host plant consumption of the males used as lures and responses to the pheromone could thus be tested. The use of A. vittatum reared entirely without dietary cucurbitacin as bait also enabled evaluation of the potential role of cucurbitacin in pheromone biosynthesis. Trap responses were closely correlated with the rates of feeding of the beetles in the trap lures, but cucurbitacin was neither a precursor nor a prerequisite for the pheromone. Implications for early season field colonization and the adaptive significance of this pheromone are discussed.
Sensation-Seeking, Risk-Taking, and Problematic Financial Behaviors of College Students

College students are at especially high risk for serious financial problems due to easy availability of credit cards, rising tuition, and a declining economy. Arnett (Am Psychol 55:469–480, 2000) proposed 18–25 year olds may be considered emerging adults and are characterized by less stable financial situations than those who perceive themselves to be adults. A survey was given to 450 students at two Mississippi universities. The results showed student financial behaviors were related to age, gender, public assistance, adult status, sensation-seeking, and potential for problem gambling. This study is unique in that it investigated the relationship of emerging adult/adult status and other individual and socio-demographic variables to financial behaviors among college students, a conceptualization that has not been explored in the past.
Hydrodynamics of Liquid Helium II

A brief account of macroscopic hydrodynamic theory of liquid helium II which describes most of the experimental observations on the thermal and mechanical behavior of liquid helium below the Svlvania Electr point is given. (A.C.)
Predicament and promise: The internal evaluator as ethical leader

Internal evaluators encounter risks but also significant opportunities to strengthen organizational and professional ethics. Potential contributions depend, in part, on the conjunction of ethics and evaluation in the role of the internal evaluator as the person specially commissioned to investigate value and render judgment based on evidence gathered. At the same time, risks increase when evaluation and ethics are brought together. In the words of one evaluator, “These are rather dangerous moments because a lot of energy is created when an evaluator expresses ethical values such as these. We have a great deal of power, whether we like to think so or not” (Cartland, 2010). This article clarifies the risks in order to free up the potential. © Wiley Periodicals, Inc., and the American Evaluation Association.
Fetal tissue engineering: in utero tracheal augmentation in an ovine model.

Abstract Background/Purpose: This study was aimed at comparing fetal tissue engineering with autologous free grafting in an ovine model of in utero tracheal repair. Methods: Chondrocytes were isolated from both elastic and hyaline cartilage specimens harvested from fetal lambs and expanded in vitro. Cells were seeded dynamically onto biodegradable scaffolds, which then were maintained in a rotating bioreactor for 6 to 8 weeks. Constructs subsequently were implanted into fetal tracheas (n = 15), in a heterologous fashion (group I). In group II, fetuses (n = 5) received autologous free grafts of elastic cartilage harvested from the ear as tracheal implants. In vivo specimens were harvested for histologic analysis at different time-points postimplantation. Results: In the 12 of 15 surviving fetuses of group I, all constructs were found to resemble normal hyaline cartilage, engraft well despite their heterologous origin, and display time-dependent epithelialization derived from the native trachea. All autologous free grafts were engrafted and epithelialized at birth, retaining histologic characteristics of elastic cartilage, but were more deformed than engineered constructs. Of the lambs allowed to reach term, 5 of 5 in the engineered group and 4 of 5 in the free graft group could breathe spontaneously. Conclusions: (1) Tissue-engineered cartilage, as well as autologous free grafts, can be implanted successfully into the fetal trachea, resulting in engraftment and function. (2) Engineered cartilage provides enhanced structural support after implantation into the fetal trachea when compared with free grafts. Prenatal tracheoplasty may prove useful for the treatment of severe congenital tracheal malformations. J Pediatr Surg 37:1000-1006. Copyright 2002, Elsevier Science (USA). All rights reserved.
Anesthesia and Supportive Care During and After Cardiac Surgery

Abstract Since the establishment of open-heart surgery in 1953, surgical mortality has been reduced considerably, undoubtedly due to greater experience in anesthetic management, more complete and curative surgical repair, and improved postoperative care. This review outlines the principles of anesthesia and supportive care as they relate to the changes taking place in the human body during and after operation. A patient undergoing a cardiac operation needs light anesthesia, controlled ventilation with adequate oxygenation, and abolition of vagal stimulation. Monitoring must be sufficient to provide information on the changes taking place within the patient. An understanding of the pathophysiology of acquired and congenital heart disease and of the associated metabolic and electrolyte changes is imperative for the management of the patient during anesthesia and in the postoperative period. Perfusion produces a highly abnormal state, and the severity of complications varies with its duration. Postoperative care is closely related to the events occurring during operation, but careful observation to detect trends early, leading to preventive rather than curative treatment, may minimize serious developments.
Conditions That Promote Teacher Learning for Effective Chemistry Teaching.

AbstractThis article describes a professional development program that inspired some high school teachers to drastically reshape their teaching of chemistry toward a more learner-centered practice. Through interviews, they identified a freedom to explore and a sense of being trusted and respected as key aspects that supported this new approach. Rather than advocating a single outcome, the expectation is that teachers will refine their practice in ways that are important for their own contexts.
Image algebra preprocessor for the MasPar parallel computer

The development of a preprocessor for image algebra on the MasPar computer, a SIMD processor array, is discussed. One of the parallel languages used on the MasPar is MPL, a parallel version of the programming language C. This machine and language were chosen because of the close correspondence between MPL and image algebra and, as a result, MPL is easily extended to include image algebra. The preprocessor consists of three primary components: the lexical analyzer, the parser, and the code generator. The lexical analyzer converts the input stream into tokens the parser recognizes. The parser checks the program for syntax errors.The code generator produces MPL source code which is then compiled and run on the MasPar. The architecture of the MasPar computer is reviewed, and in particular the structures used for routing data through the array are examined. The parallel language MPL is also reviewed, with attention given to the methods in which the extensions to C in MPL interact with the MasPar architecture. The close correspondence between MPL and image algebra is specifically discussed. The authors present the structure and development of the image algebra preprocessor, including possible future extensions. Examples of image algebra preprocessor code and the corresponding MPL code produced by the preprocessor are given.
Proteomic profiling of intact proteins using WAX-RPLC 2-D separations and FTICR mass spectrometry.

We investigated the combination of weak anion exchange (WAX) fractionation and on-line reversed-phase liquid chromatography (RPLC) separation using a 12 T FTICR mass spectrometer for the detection of intact proteins from a Shewanella oneidensis MR-1 cell lysate. This work aimed at optimizing intact protein detection for profiling proteins at a level that incorporates their modification state. A total of 715 intact proteins were detected, and the combined results from the WAX fractions and the unfractionated cell lysate were aligned using LC-MS features to facilitate protein abundance measurements. Protein identifications and post-translational modifications were assigned for ∼10% of the detected proteins by comparing intact protein mass measurements to proteins identified in peptide MS/MS analysis of an aliquot of the same fraction. Intact proteins were also detected for S. oneidensis lysates obtained from cells grown on 13C-, 15N-depleted media under aerobic and sub-oxic conditions. The strategy can be r...
Modeling and measurement of radio propagation in rectangular tunnels at low frequencies

Radio propagation in tunnels has been investigated for decades and many methods for modeling tunnel propagation have been proposed. Most of the methods, however, assume that the wavelengths of interest are much less than the tunnel dimensions, which limits their application to relatively high frequency signals. In this paper, we investigate a numerical method that can be applied to analyze power attenuation at low frequencies as wavelengths are comparable to tunnel dimensions. The method is based on numerically solving the complex boundary conditions for frequencies of interest. We validate the method with wideband (spanning from 25 MHz to 1525 MHz) propagation measurements in a rectangular tunnel without an arched ceiling.
Vaccination considerations in the asplenic patient

Overwhelming postsplenectomy sepsis is a rare but devastating and often lethal disease. Although vaccines are available, their proper use may be questioned. Standardization of protocols for the immunization of asplenic patients should be universal, thus, likely improving on their use. This article reviews the vaccines to be administered to the asplenic patient.
ILIO-ILIAC ARTERIOVENOUS FISTULA FOLLOWING INTERVERTEBRAL DISC SURGERY.

Summary The clinical and roentgenographic findings of an ilio-iliac arteriovenous fistula nine years following intravertebral disc surgery are described. The mode of injury is discussed, and the vascular injuries following disc surgery are reviewed.
Electrical activity and insulin release in pancreatic beta cells

Abstract The pancreatic beta cell, which is responsible for insulin secretion from the islets of Langerhans, exhibits a complex pattern of membrane-potential oscillations called bursting. These oscillations are induced by glucose and are strongly correlated with the release of insulin. Recently a number of the ion channels which are responsible for carrying membrane currents in the beta cell have been uncovered. This has led to several hypothesized mechanisms for bursting and a good deal of mathematical modeling. In this paper the progress in understanding bursting in the beta cell is reviewed, including the impact of the discovery of the ATP-inactivated, ADP-modulated channel on modeling and the effect of single-channel events on electrical activity.
Correlates of gut community composition across an ant species (Cephalotes varians) elucidate causes and consequences of symbiotic variability

Insect guts are often colonized by multispecies microbial communities that play integral roles in nutrition, digestion and defence. Community composition can differ across host species with increasing dietary and genetic divergence, yet gut microbiota can also vary between conspecific hosts and across an individual's lifespan. Through exploration of such intraspecific variation and its correlates, molecular profiling of microbial communities can generate and test hypotheses on the causes and consequences of symbioses. In this study, we used 454 pyrosequencing and TRFLP to achieve these goals in an herbivorous ant, Cephalotes varians, exploring variation in bacterial communities across colonies, populations and workers reared on different diets. C. varians bacterial communities were dominated by 16 core species present in over two-thirds of the sampled colonies. Core species comprised multiple genotypes, or strains and hailed from ant-specific clades containing relatives from other Cephalotes species. Yet three were detected in environmental samples, suggesting the potential for environmental acquisition. In spite of their prevalence and long-standing relationships with Cephalotes ants, the relative abundance and genotypic composition of core species varied across colonies. Diet-induced plasticity is a likely cause, but only pollen-based diets had consistent effects, altering the abundance of two types of bacteria. Additional factors, such as host age, genetics, chance or natural selection, must therefore shape natural variation. Future studies on these possibilities and on bacterial contributions to the use of pollen, a widespread food source across Cephalotes, will be important steps in developing C. varians as a model for studying widespread social insect-bacteria symbioses.
Groupwise successive interference cancellation for multirate CDMA based on MMSE criterion

In this work, groupwise successive interference cancellation scheme for multirate CDMA signals is proposed. The proposed detector operation is based on the minimum mean square error (MMSE) criterion. It has the promise of decision feedback interference cancellation for superior performance compared to the linear MMSE detection at the cost of a moderate increase in complexity. In groupwise detection, users are grouped according to their processing gain or data rate, i.e., users with the same processing gain or data rate are grouped together, then detected. Users with the lowest processing gain or highest data rate are detected first, neglecting the presence of the other users in the system. Interference between the groups is cancelled in a successive order. The BER of the groupwise successive MMSE interference canceler is compared with the BER multirate linear MMSE detector and multirate decorrelating detector. The results show that the groupwise successive MMSE interference canceler yields better performance than the multirate linear MMSE detector and multirate decorrelating detector. When the system is highly loaded, the groupwise successive MMSE interference canceler can offer a better performance than the multirate linear MMSE detector and the multirate conventional detector.
Computable error bounds for approximate periodic solutions of autonomous delay differential equations

In this paper, we prove a result that says: Given an approximate solution and frequency to a periodic solution of an autonomous delay differential equation that satisfies a certain noncriticality condition, there is an exact periodic solution and frequency in a neighborhood of the approximate solution and frequency and, furthermore, numerical estimates of the size of the neighborhood are computed. Methods are outlined for estimating the parameters required to compute the errors. An application to a Van der Pol oscillator with delay in the nonlinear terms is given.
An Analysis of the Americans With Disabilities Act (ADA) in the Twenty-First Century

Abstract In this paper, the author overviews the key components of the ADA. A discussion is offered on why and how persons with disabilities are discriminated against. The standard stereotypes often heard about persons with disabilities are offered. Critical United States Supreme Court decisions are presented; these decisions have greatly limited the power of the ADA in protecting the rights of persons with disabilities. Even though the United States Supreme Court has narrowed the impact of the ADA in American life, a number of Equal Employment Opportunity Commission (EEOC) cases are presented, suggesting this federal agency is attempting to protect persons with disabilities against discrimination. The final part of the paper deals with the topic of advocacy; advocacy may well be one of the most effective tools to help insure that the rights of people with disabilities are protected in the 21st century.
Chlamydia pneumoniae impairs the innate immune response in infected epithelial cells by targeting TRAF3

Type I IFNs are induced during microbial infections and have well-characterized antiviral activities. TRAF3 is a signaling molecule crucial for type I IFN production and, therefore, represents a potential target for disarming immune responses. Chlamydia pneumoniae is a human pathogen that primarily infects respiratory epithelial cells; the onset of symptoms takes several weeks, and the course of infection is protracted. C. pneumoniae has also been associated with a variety of chronic inflammatory conditions. Thus, typical C. pneumoniae infections of humans are consistent with an impairment in inflammatory responses to the microorganism. We demonstrate that infection of epithelial cells with C. pneumoniae does not lead to IFN-β production. Instead, infected cells are prevented from activating IFN regulatory factor 3. This effect is mediated by C. pneumoniae-dependent degradation of TRAF3, which is independent of a functional proteasome. Hence, it is likely that C. pneumoniae expresses a unique protease targeting TRAF3-dependent immune effector mechanisms.
Genome-wide analysis of chromatin architecture in Oxytricha trifallax: a single-celled eukaryote with 16,000 tiny chromosomes

The pond-dwelling ciliate Oxytricha trifallax is a model system for the study of gene regulatory mechanisms. It possesses a heterochromatin-rich germline micronucleus, and a transcriptionally active somatic macronucleus (MAC). The MAC genome is highly fragmented, consisting of >16,000 unique “nanochromosomes”, with a mean size of 3.2kb. Consequently, only a limited number of nucleosomes can be accommodated in short nanochromosomes. Nanochromosome size does not vary in multiples of ~147bp corresponding to mono-nucleosome-sized DNA, suggesting that nucleosome depleted regions may be especially prevalent. This unusual genome architecture presents novel challenges for the regulation of gene expression. The efficacy and prevalence of chromatin-mediated gene regulation thus remain unclear in Oxytricha. In addition, the paucity of non-coding DNA suggests that promoters in Oxytricha are highly compact, and may be organized differently from other eukaryotes. Our study aims to uncover how the chromatin structure of promoters and coding regions is constrained by chromosome length in the vegetative Oxytricha MAC. To address this, we characterize the chromatin landscape of the MAC through genome-wide mapping of nucleosome positions and DNase I hypersensitive sites. By integrating these studies with existing RNA Polymerase II ChIP-seq and mRNA-seq data, we investigate how chromatin organization varies with nanochromosome length, gene number, and transcriptional output. These data will also be coupled with transcription start site annotations to define promoter architecture in the Oxytricha MAC, including the presence and position of regulatory motifs, the distribution of transcription start sites within a promoter, and local chromatin accessibility. Together, this integrated analysis will test the contribution of chromatin structure to gene expression regulation, and illuminate the variation of eukaryotic gene regulatory mechanisms.
Communication without Constellation? Habermas's Argumentative Turn in (and Away from) Critical Theory

This article contrasts the recent communicative and epistemological conceptualizations of Jurgen Habermas with those provided by earlier critical theorists such as Walter Benjamin, Max Horkheimer, and Theodor Adorno. I argue that Habermas's “argumentative turn” breaks sharply with certain basic assumptions about language, discourse and knowledge common to his predecessors. While the earlier theorists were operating with assumptions derived from the “declarative” rhetorical lineage of German early romanticism and Hegelian Marxism, Habermas has returned to the hegemonic assumptions of Western “demonstrative” rhetoric. His prioritizing of oral argumentative discourse over written forms of nonargumentative “indirect communication” leaves little space for the kind of “constellational” cognition and “combinational” articulation considered essential by the earlier theorists. Some of the theoretical and political implications of Habermas's argumentative turn away from declarative critical theory are then discussed.
Race and the CIO: The Possibilities for Racial Egalitarianism During the 1930s and 1940s

minority workers in practice, have undergone immense change. During the 1930s and 1940s, many individuals and groups who supported racial equal ity, including W. E. B. Du Bois, considered the CIO the leading organiza tion in the struggle for Black freedom. Today, many people, including Herbert Hill, consider the CIO unions of the 1930s and 1940s barely better than the racially discriminatory American Federation of Labor (AFL) unions that excluded African-American workers from union membership and employment. In this latter rendition, CIO unions, even during their prime, were merely another vehicle for maintaining white employment, white possession of more desirable jobs, and other white privileges, their differences from AFL unions largely due to the industrial milieu in which the CIO operated. Thus, the CIO unions were themselves a major obstacle to African-American advancement-part of the problem, not part of the
TRANSFER CONDITIONS OF LATINA/O COMMUNITY COLLEGE STUDENTS: A SINGLE INSTITUTION CASE STUDY

This study reported in this article examined the transfer process for Latina/o students at Esperanza Community College. Esperanza is one of the 108 community colleges in California with one of the largest concentrations of Latina/o students. In California, 42 out of every 100 Latina/o public high school graduates pursue some form of higher education. For most, the community college is the entry point, Of these, 32 out of every 100 students begin their pursuit of higher education at a California community college. An average of three Latina/o students transfers to a university. Recommendations considered essential to create a prevailing community college transfer culture are offered.
A CDK-related kinase regulates the length and assembly of flagella in Chlamydomonas

Little is known about how cells regulate the size of their organelles. In this study, we find that proper flagellar length control in Chlamydomonas reinhardtii requires the activity of a new member of the cyclin-dependent kinase (CDK) family, which is encoded by the LF2 (long flagella 2) gene. This novel CDK contains all of the important residues that are essential for kinase activity but lacks the cyclin-binding motif PSTAIRE. Analysis of genetic lesions in a series of lf2 mutant alleles and site-directed mutagenesis of LF2p reveals that improper flagellar length and defective flagellar assembly correlate with the extent of disruption of conserved kinase structures or residues by mutations. LF2p appears to interact with both LF1p and LF3p in the cytoplasm, as indicated by immunofluorescence localization, sucrose density gradients, cell fractionation, and yeast two-hybrid experiments. We propose that LF2p is the catalytic subunit of a regulatory kinase complex that controls flagellar length and flagellar assembly.
Infrared Radiative Properties of the Antarctic Plateau from AVHRR Data. Part I: Effect of the Snow Surface

The effective scene temperature, or ‘‘brightness temperature,’’ measured in channel 3 (3.5‐3.9 mm) of the Advanced Very High Resolution Radiometer (AVHRR) is shown to be sensitive, in principle, to the effective particle size of snow grains on the Antarctic plateau, over the range of snow grain sizes reported in field studies. In conjunction with a discrete ordinate method radiative transfer model that couples the polar atmosphere with a scattering and absorbing snowpack, the thermal infrared channels of the AVHRR instrument can, therefore, be used to estimate effective grain size at the snow surface over Antarctica. This is subject to uncertainties related to the modeled top-of-atmosphere bidirectional reflectance distribution function resulting from the possible presence of sastrugi and to lack of complete knowledge of snow crystal shapes and habits as they influence the scattering phase function. However, when applied to NOAA-11 and NOAA-12 AVHRR data from 1992, the snow grain effective radii of order 50 mm are retrieved, consistent with field observations, with no apparent discontinuity between two spacecraft having different viewing geometries. Retrieved snow grain effective radii are 10‐20mm larger when the snow grains are modeled as hexagonal solid columns rather than as spheres with a Henyey‐ Greenstein phase function. Despite the above-mentioned uncertainties, the retrievals are consistent enough that one should be able to monitor climatically significant changes in surface snow grain size due to major precipitation events. It is also shown that a realistic representation of the surface snow grain size is critical when retrieving the optical depth and effective particle radius of clouds for the optically thin clouds most frequently encountered over the Antarctic plateau.
Iso-index coupled-wave electrooptic filter

A new optical filter, first demonstrated more than a decade ago and recently extended to other frequencies and materials, is based on the accidental isotropy of refractive indexes that occurs in certain uniaxial semiconductors near the band edge. This paper shows how coupling of light energy can take place between ordinary and extraordinary polarizations at the isotropic point by application of a dc electric field. When placed between crossed polarizers, these materials can thus act as narrow-band filters. The field-of-view characteristics have been analyzed; and it is concluded that this type of filter can, in principle, accommodate a 2π field with less than 20 percent increase in passband over that of the narrow-field condition. It is noted, in particular, that AgGaS 2 exhibits the required change of sign of its birefringence at a wavelength of 4970 A (blue-green), with a rate of change that could provide a passband of only 0.2 A in a 1 cm sample.
A multi-plane state machine agent model

This paper presents a framework for implementing collaborative network agents. Agents arc assembled dynamically from components into a structure described by a multi-plane state machine model. This organization lends itself to an elegant implementations of remote control, collaboration, chcckpointing and mobility, defining features of an agent system. It supports techniqucs, like agent surgery difficult to reproduce with other approaches. The reference implementation for our model, the Bond agent system, is distributed under an open source license and can be downloaded from http;llbond.cs.purdue.edu.
Poly(4‐vinylpyridine)

[9017-40-7] (C7H7N)n (MW n(105.15)) (·HCl) [29323-87-3] (C7H8ClN)n (MW n(141.60)) (pyridine functional group in easily regeneratable solid form;1 acid scavenger;2 basic catalyst for Knoevenagel reactions;2 acid salts are mild acid catalysts3) Alternate Names: P(4-VP); Reillex™. Physical Data: Reillex 402: d 0.45 g cm−3. Reillex 425: d 0.29 g cm−3. Solubility: insol all solvents; polymer swells when added to aqueous and nonaqueous solvents. Form Supplied in: Reillex 402: 60 mesh, off-white granular powder. Reillex 425: 18–50 mesh, off-white beads. Drying: water may be removed from the polymer with toluene or other solvents that form water azeotropes. Analysis of Reagent Purity: aqueous titration with acid; Reillex 402 has 8.8 mequiv/g H+ capacity and Reillex 425 has 5.5 mequiv/g H+ capacity. Handling, Storage, and Precautions: extremely stable polymer best stored in tightly closed containers; after use the free base form of the polymer can be regenerated for further use by treatment with aqueous NaOH.
An attempt to make an issue less murky: a comparison of four systems for infection precautions.

Birnbaum and others1 recently published an article about adoption of guidelines for Universal Precautions (UP) and Body Substance Isolation (BSI) in Canadian acute-care hospitals. The authors pointed out that terminology was used inconsistently among the Canadian hospitals and that there was considerable confusion about the meaning of different terms. As two of the developers of the BSI system,2-6 we have been impressed that the philosophical differences among the isolation systems are also misinterpreted by many. The primary purpose of an isolation system, and why and when and it is implemented, form the bases for the philosophical differences among the different systems. Failing to understand the fundamental differences leads practitioners incorrectly to apply the methods of the system in use at their facilities and also leads to inconsistency in practice among healthcare workers.
Characterization of nonlinear behavior in a tunable phase shifter using ferroelectric PZT thin-film capacitors and its effect on system performance

In this paper, the nonlinear behavior in a tunable phase shifter using ferroelectric lead zirconate titanate (PZT) thin-film capacitors is described. The phase shifter is of reflection-type consisting of a coplanar waveguide Lange coupler and two ferroelectric PZT varactors on high resistivity silicon substrate. The nonlinearity is characterized by measuring the AM/AM and AM/PM transfer curves of the device, a technique that is commonly used to characterize power amplifiers. The responses of the device to two-tone and quadrature-amplitude-modulation waveforms are then estimated according to the measured transfer curves.
Novel GaAs Schottky barrier diode structures

Design of Schottky barrier diodes for use in high frequency applications is limited by the tradeoff between V/sub 0/, the inverse slope parameter, and the R/sub s/C/sub j0/ product. This, in turn limits the minimum noise and conversion loss of the receivers which use these devices. Two technologies, the graded doped barrier diode and the Schottky barrier membrane diode, which enhance the performance of the device by reducing parasitic elements, are discussed. The graded doped barrier diode (GDB) has reduced the minimum possible R/sub s/C/sub j0/ for a given V/sub 0/. For a receiver using a standard device, the GDB will provide an improvement in noise without sacrificing conversion loss. The Schottky barrier membrane diode greatly reduces the skin effect resistance. Compared to a standard device, this structure will yield a significant improvement in conversion loss. GaAs membranes of 2.7- mu m thickness have been fabricated and the current research emphasis is on the formation of the ohmic contact. Very recent work on ohmic contracts has provided many possible solutions, and these contact technologies are being evaluated for use in this device. Successful fabrication of a Schottky barrier membrane diode will greatly improve the sensitivity of submillimeter-wavelength heterodyne receivers. >
Phenotypic evolution and the genetic architecture underlying photoperiodic time measurement

A wide variety of higher plants, vertebrates, and arthropods use the length of day to synchronize growth, development, reproduction, dormancy, and migration with the changing seasons. In the pitcher-plant mosquito, Wyeomyia smithii, critical photoperiod mediating the onset and maintenance of larval diapause has evolved about 10 standard deviations in mean critical photoperiod between the ancestral, Gulf Coast populations, and the derived, Canadian populations. We are seeking to understand how this evolution has been accomplished at both the genetic and the physiological levels. At the genetic level, average heterozygosity at protein-coding loci decreases with latitude of origin, while genetic variation for photoperiodic response increases with latitude of origin, particularly within the formerly glaciated regions of North America. Hybridization experiments reveal widespread genetic differences in critical photoperiod due to epistasis. We ascribe the increase in genetic variation in photoperiodic response, despite directional and stabilizing selection to the contrary, to the release of additive from epistatic variance during successive founder events in W. smithii’s northward dispersal following recession of the Laurentide Ice Sheet, and to the resulting genetic drift and reorganization of genetic architectures in descendent populations. At the physiological level, northern populations of W. smithii, as well as northern populations of spider mites, flies, moths, and beetles in both North America and Europe show a declining expression of the rhythmic component of photoperiodic response. In Drosophila melanogaster, when the epistatic coupling between the period locus and photoperiodic response is disrupted, the critical photoperiod is shifted towards shorter daylengths; analogously in W. smithii, when epistatic interactions are disrupted in the recombining generations of hybrid populations, the critical photoperiod is shifted towards shorter daylengths. The implications here are (1) that in W. smithii, it is the epistatic modification of the photoperiodic response curve by the circadian clock that is being disrupted in the recombining generations and (2) that post-glacial range expansion into the North-Temperate Zone by arthropods in general may involve uncoupling of the circadian and photoperiodic clocks. Despite the tremendous advances that have been made in understanding circadian rhythmicity at the molecular level, virtually nothing is known about how or whether any of the downstream ‘clock-controlled genes’ connect with photoperiodic time measurement. Except in W. smithii, little is known about how this connection changes with seasonal adaptation of photoperiodic response through evolutionary time. It is our goal and desire that our top–down approach to the evolution of photoperiodic time measurement will meet and mesh with the bottom–up approach that is being developed so fruitfully for circadian clocks.  2001 Elsevier Science Ltd. All rights reserved.
Cell labeling and proximity dependent biotinylation with engineered monomeric streptavidin

Because streptavidin is a homotetramer, it can bind multiple biotinylated ligands and cause target aggregation. To allow biotin detection without clustering, we previously engineered monomeric streptavidin (mSA) that is structurally similar to a single streptavidin subunit. Introducing the S25H mutation near the binding site increases the biotin dissociation half-life t1/2 to 83 minutes. The slowly dissociating mutant, mSA2, is useful in imaging studies because it allows stable labeling of biotinylated targets. We show that mSA2 conjugated with Alexa 488 binds biotinylated receptors on HEK293 with high specificity, and bound mSA2–Alexa488 does not dissociate significantly during an imaging study lasting 50 minutes. As a structural monomer, mSA2 can be fused to other proteins to create bifunctional molecules. We tested the use of mSA2 in proximity dependent biotinylation, in which mSA2 is fused to a peptide or a protein that binds a protein of interest (POI) and is used to recruit photoactivatable biotin (PA-biotin) to the target molecule. Once the resulting cluster of interacting proteins is subjected to UV-initiated distance-dependent biotinylation, subsequent affinity purification of biotinylated proteins on streptavidin beads can identify protein molecules that interact with POI. In addition to proteins that directly interact with the mSA2 fusion, mSA2 also induces biotinylation of other proteins that are associated through a series of noncovalent interactions. We show that mSA2 fused to an antibody recognition domain can be recruited to the kinase Erk-2 using a commercially available antibody and induce biotinylation of a known Erk-2 substrate, GST-Elk-1. Therefore, mSA2 can be used to implement proximity dependent biotinylation and detect transient enzyme-substrate interactions.
Minority Carrier Lifetimes in InSb/InAsSb Quantum Dot and InAsSb nBn Photodetectors

The energy level scheme and the minority carrier lifetime in a type-II midwave InSb/InAs 0.92 Sb 0.08 quantum dot structure were compared with bulk InAs 0.915 Sb 0.085 using photoluminescence, absorption, and optical modulation response. Two hole energy levels separated by ~65 meV were identified in the quantum dots, and a decrease of the hole energy barrier with increasing temperatures was observed. The quantum dot minority carrier lifetime increased from 700 ns at 77 K to 1230 ns at 175 K, and is significantly longer than the bulk InAs 0.915 Sb 0.085 lifetime of 300 ns. By insertion of quantum dots in the bulk material, the dominating recombination mechanism changed from the Shockley-Read-Hall to radiative recombination.
Inferring Clinical Workflow Efficiency via Electronic Medical Record Utilization

Complexity in clinical workflows can lead to inefficiency in making diagnoses, ineffectiveness of treatment plans and uninformed management of healthcare organizations (HCOs). Traditional strategies to manage workflow complexity are based on measuring the gaps between workflows defined by HCO administrators and the actual processes followed by staff in the clinic. However, existing methods tend to neglect the influences of EMR systems on the utilization of workflows, which could be leveraged to optimize workflows facilitated through the EMR. In this paper, we introduce a framework to infer clinical workflows through the utilization of an EMR and show how such workflows roughly partition into four types according to their efficiency. Our framework infers workflows at several levels of granularity through data mining technologies. We study four months of EMR event logs from a large medical center, including 16,569 inpatient stays, and illustrate that over approximately 95% of workflows are efficient and that 80% of patients are on such workflows. At the same time, we show that the remaining 5% of workflows may be inefficient due to a variety of factors, such as complex patients.
Encapsulation of Cells in Agarose Beads

For the analysis of large DNA fragments using pulsed-field gel electrophoresis (PFGE), it is necessary to first embed the cells in agarose to prevent shearing of the DNA during protein extraction and restriction enzyme digestion. The speed and efficiency with which these steps are performed is based on the diffusion rate of the buffers and proteins in each step.
Gas discharge tube-based variable RF attenuator

In this paper, tunable RF attenuation using low temperature plasma technology is investigated theoretically and experimentally. Specifically, gas discharge tubes (GDTs) are employed as plasma cells and their impedance is tuned from a high level (zero current or off-mode) to a low level (DC discharge current or on-mode). A proof-of-concept prototype with two independently-controlled GDTs in a series-shunt topology results in a continuously variable attenuator with maximum attenuation of 20±1 dB in the 0.5–1.2 GHz range. The proposed GDT-based approach may be employed as an RF attenuation technology particularly in emerging applications where conventional techniques cannot be used due to high temperature and/or power.
Mastery-Based Virtual Reality Robotic Simulation Curriculum: The First Step Toward Operative Robotic Proficiency

Objective Hepatobiliary surgery is a highly complex, low-volume specialty with long learning curves necessary to achieve optimal outcomes. This creates significant challenges in both training and measuring surgical proficiency. We hypothesize that a virtual reality curriculum with mastery-based simulation is a valid tool to train fellows toward operative proficiency. This study evaluates the content and predictive validity of robotic simulation curriculum as a first step toward developing a comprehensive, proficiency-based pathway. Design A mastery-based simulation curriculum was performed in a virtual reality environment. A pretest/posttest experimental design used both virtual reality and inanimate environments to evaluate improvement. Participants self-reported previous robotic experience and assessed the curriculum by rating modules based on difficulty and utility. Setting This study was conducted at the University of Pittsburgh Medical Center (Pittsburgh, PA), a tertiary care academic teaching hospital. Participants A total of 17 surgical oncology fellows enrolled in the curriculum, 16 (94%) completed. Results Of 16 fellows who completed the curriculum, 4 fellows (25%) achieved mastery on all 24 modules; on average, fellows mastered 86% of the modules. Following curriculum completion, individual test scores improved (p Conclusions In a cohort of board-certified general surgeons who are novices in robotic surgery, a mastery-based simulation curriculum demonstrated internal validity with overall score improvement. Time to complete the curriculum was manageable.
Flavonoid intake is inversely associated with obesity and C-reactive protein, a marker for inflammation, in US adults.

Recent studies have demonstrated the importance of flavonoid intake and disease risk, however the association between flavonoid intake and obesity has not been evaluated in a nationally representative sample of US adults. The objective of the study was to evaluate the association between flavonoid consumption and established risk factors for obesity and obesity-related inflammation. Data from a nationally representative sample of 9551 adults who participated in the 2005–2008 National Health and Nutrition Examination Survey (NHANES) were analyzed. Flavonoid consumption was inversely associated with obesity in both men and women in multivariate models. Adults in the highest quartile of flavonoid intake had significantly lower body mass index and waist circumference than those in the lowest quartile of flavonoid intake (P<0.03 and P<0.04, respectively), and flavonoid intake was inversely related to C-reactive protein levels in women (p-trend, 0.01). These findings support a growing body of laboratory evidence that flavonoid consumption may be beneficial for disease prevention.
Multi-Wavelength Determination of Total Ozone and Ultraviolet Irradiance

An improved analysis of our multi-wavelength least square method of total ozone determination is given for various monochromator band passes. The refinements include use of new input data as described in another conference paper, improved instrument slit function characterization and absolute calibration. The requirements for a system which will simultaneously provide accurate ozone monitoring and ultraviolet spectral irradiance monitoring are defined.
A comprehensive study of real-world numerical bug characteristics

Numerical software is used in a wide variety of applications including safety-critical systems, which have stringent correctness requirements, and whose failures have catastrophic consequences that endanger human life. Numerical bugs are known to be particularly difficult to diagnose and fix, largely due to the use of approximate representations of numbers such as floating point. Understanding the characteristics of numerical bugs is the first step to combat them more effectively. In this paper, we present the first comprehensive study of real-world numerical bugs. Specifically, we identify and carefully examine 269 numerical bugs from five widely-used numerical software libraries: NumPy, SciPy, LAPACK, GNU Scientific Library, and Elemental. We propose a categorization of numerical bugs, and discuss their frequency, symptoms and fixes. Our study opens new directions in the areas of program analysis, testing, and automated program repair of numerical software, and provides a collection of real-world numerical bugs.