cssi/SciSciGPT-SciSciNet huggingface dataset:
Biosynthesis of Lipoprotein by Rat Intestinal Mucosa

Abstract Lymph chylomicrons are at the lipid-rich end of the spectrum of the lipoproteins. The nature of their protein moiety and its biosynthesis have not yet been fully elucidated. Observations are reported on the incorporation of radioactive leucine into a "lowest density lipoprotein" by mucosal cells of the small intestine isolated from the rat during absorption of fat. The amino acid incorporation exhibited the characteristic energy requirement and sensitivity to inhibitors of other systems for biosynthesis of proteins. The protein moiety was not homogeneous, but appeared to consist of a small number of species that could be separated by thin layer electrophoresis in starch granules. Similar, but nonidentical, electrophoretic patterns were obtained with the residual soluble intracellular protein of the intestinal mucosa and with chylomicrons of intestinal lymph. The lowest density lipoprotein was isolated from a homogenate of the mucosal cells. After removal of lipids by extraction with organic solvents, the protein moiety exhibited several unusual properties in addition to its affinity for lipids: (a) a predominance of apolar amino acids, (b) resistance to fractionation procedures involving ionic properties, (c) considerable solubility in organic solvents, and (d) peculiarities of the peptide map that were related to the foregoing features. Peptide maps were obtained after proteolytic digestion of the protein moieties of the lowest density lipoprotein fraction, the residual soluble protein, and lymph chylomicrons by means of two-dimensional electrophoresis and chromatography. Unusual maps were obtained in which most of the peptide fragments failed to move upon electrophoresis over a broad pH range, but were readily resolved by chromatography in organic solvents. Strong, although imperfect, resemblance was noted among the peptide maps of all three protein fractions. Preliminary studies of low and high density lipoproteins of rat serum revealed different, more complex peptide maps. No definitive conclusion could be drawn about the specificity of the protein which becomes associated with lipid during absorption through the intestinal mucosa. A speculative interpretation of the aforementioned similarity in peptide maps led us to suggest that lipids in transit become associated with some of the more abundant soluble proteins of the mucosal cells and that the resulting lipoprotein complexes appear in the chylomicrons of intestinal lymph. Thin layer methods of chromatography and electrophoresis were extensively employed. Their convenience and great sensitivity permitted detailed studies to be carried out on submilligram quantities of material.
A Niche Maintaining Germ Line Stem Cells in the Drosophila Ovary

Stromal cells are thought to generate specific regulatory microenviroments or "niches" that control stem cell behavior. Characterizing stem cell niches in vivo remains an important goal that has been difficult to achieve. The individual ovarioles of the Drosophila ovary each contain about two germ line stem cells that maintain oocyte production. Here we show that anterior ovariolar somatic cells comprising three cell types act as a germ line stem cell niche. Germ line stem cells lost by normal or induced differentiation are efficiently replaced, and the ability to repopulate the niche increases the functional lifetime of ovarioles in vivo. Our studies implicate one of the somatic cell types, the cap cells, as a key niche component.
Influential nodes in a diffusion model for social networks

We study the problem of maximizing the expected spread of an innovation or behavior within a social network, in the presence of “word-of-mouth” referral. Our work builds on the observation that individuals’ decisions to purchase a product or adopt an innovation are strongly influenced by recommendations from their friends and acquaintances. Understanding and leveraging this influence may thus lead to a much larger spread of the innovation than the traditional view of marketing to individuals in isolation. In this paper, we define a natural and general model of influence propagation that we term the decreasing cascade model, generalizing models used in the sociology and economics communities. In this model, as in related ones, a behavior spreads in a cascading fashion according to a probabilistic rule, beginning with a set of initially “active” nodes. We study the target set selection problem: we wish to choose a set of individuals to target for initial activation, such that the cascade beginning with this active set is as large as possible in expectation. We show that in the decreasing cascade model, a natural greedy algorithm is a 1-1/ e-e approximation for selecting a target set of size k.
Nonlinear Effects Involved in the Generation of Type III Solar Radio Bursts

Recent observations of the simultaneous measurement of plasma waves and radiation, and electrons and radiation during type III bursts are reviewed. One-dimensional quasilinear relaxation results are considered and found to be in reasonable agreement with observations, but often inconsistent when weak turbulence wave-wave and strong turbulence processes are included. Strong turbulence processes are considered and soliton collapse is found to be important, but the steady-state plasma wave distribution in a plasma of three-dimensionally collapsing solitons is presently unknown. Radiation processes are considered from both weak and strong turbulence. Subsidiary problems such as the origin of observed and inferred plasma wave clumping are briefly considered and directions for future research are suggested.
Topical Engagement on Twitter: Using Consistency of Activity as a Means of User Segmentation

In this paper we introduce a measure for the consistency of Twitter user behavior as a way of measuring engagement with a topic. Using this measure of topical engagement, we filter tweets collected from over 90,000 Nigerian users over a three-year period concerning that country’s head of state, President Goodluck Jonathan. We show that this measure effectively identifies a small set of highly engaged users that produce a disproportionate amount of activity, both in tweet volume and mentions of other users. Additionally, we show preferential within-group activity, with these users disproportionately mentioning other highly engaged users. Lastly, we show the potential of using changes in the percentage of engaged users within the overall user set for gauging the significance of events that occurred in Nigeria over the 2011 to early 2013 period.
Influence of thermal phase fluctuations on the spectral function for a two-dimensional d-wave superconductor

We study the spectral function of a two-dimensional superconductor in a regime of strong phase fluctuations. Although the developed approach is valid for any symmetry, we concentrate on d -wave superconductors. We obtain analytical expressions for the single electron Green's function below the transition temperature and have worked out a way to extrapolate it for a finite temperatures above T{sub c}. The suggested approach is easily generalizable for other models with critical fluctuations.
Polymers and Soft Matter

Within the context of this Handbook, the combined areas ofpolymers and soft matter encompasses a vast range of complex materials, including both synthetic and natural polymers, many biological materials, and complex fluids such as colloids and viscoelastic media. What distinguishes these materials from most of those considered in other chapters of this Handbook is the macromolecular or supermolecular nature of the basic components of the material. In addition to the usual atomic level interactions responsible for chemically specific material behavior, as is found in all materials, these macromolecular and supermolecular objects exhibit topological features that lead to new, larger scale, collective nonlinear and nonequilibrium behaviors that are not seen in the constituents. As a consequence, these materials are typically characterized by a broad range of both length and time scales over which phenomena of both scientific and engineering interest can arise. In polymers, for instance, the organic nature of the molecules is responsible for both strong (intramolecular, covalent) and weak (intermolecular, van der Waals) interactions, as well as interactions of intermediate strength such as hydrogen bonds that are common in macromolecules of biological interest. In addition, however, the long chain nature of the molecule introduces a distinction between dynamics that occur along the chain or normal to it; one consequence of this is the observation of certain generic behaviors such as the “slithering snake” motion, or reptation, in polymer dynamics.
High speed buffers for op-amp characterization

Techniques for testing the frequency response of an operational amplifier (op-amp) sometimes require a buffer in the feedback path. This buffer is needed to prevent an inadvertent forward signal path from the input of the op-amp to the output of the op-amp through the feedback circuitry. The buffer must have very good linearity and a higher bandwidth than the op-amp under test. Three CMOS buffer designs are presented. Simulation results show total harmonic distortion of about 1% at frequencies as high as 10 MHz into a load capacitance at 5 pF. The buffers settle to within 1% of the final voltage in fewer than 20 ns. >
Vortex contribution to specific heat of dirty d-wave superconductors: Breakdown of scaling

Abstract We consider the problem of the vortex contribution to thermal properties of dirty d -wave superconductors. In the clean limit, the main contribution to the density of states in a d -wave superconductor arises from extended quasiparticle states which may be treated semiclassically, giving rise to a specific heat contribution δC(H) ∼ H 1/2 . We show that the extended states continue to dominate the dirty limit, but lead to a H log H behavior at the lowest fields, H c1 ∼ H ≪ H c2 . This crossover may explain recent discrepancies in specific heat measurements at low temperatures and fields in the cuprate superconductors. We discuss the range of validity of recent predictions of scaling with H 1/2 T in real samples.
On the enhanced passivity of pneumatically actuated impedance-type haptic interfaces

The stable simulation of high-stiffness surfaces remains a challenge in impedance-type haptic simulations of mechanical environments. In this paper, the authors propose an approach to achieving a stable, high-stiffness surface in a haptic interface by leveraging the open-loop properties of pneumatic actuators. By using the open-loop component of the actuator stiffness as a primary component of stiffness simulation in a haptic interface, the system requires a comparatively small component of simulated stiffness from the closed-loop control of the actuator. A passivity analysis is presented describing how the presence of an open-loop stiffness enhances the range of passivity of haptically simulated high-stiffness surfaces. Experimental results both with and without a human operator are presented that demonstrate the effectiveness of the approach and its enhanced passivity relative to motor-actuated devices.
Re-evaluating the environment in developmental evolution

This manuscript reviews our growing understanding of the role of environmental conditions in shaping development and developmental evolution. It then discusses how this enhanced understanding increasingly questions our intuitive notions of the environment as separable from - and external to - organisms, as a selective force that is passive rather than generative, and as an external agent that organisms respond to, rather than one that organisms actively modify to suit their responses. Throughout I highlight examples of case studies in evo devo and beyond that - by integrating a revised evaluation of the environment into their research programs - have been able to advance long-standing and critical questions in the biological sciences. I end by summarizing several theoretical frameworks that are already well in place to guide a more systemic re-integration of the role of environmental conditions in evo devo.
Real‐Time Realities: The Application of Commercial Information Technology to Combat Control Systems

The Navy is steward to the most lethal arsenal of national and combat power ever amassed. The command responsibilities associated with such destructive force require us to always be in complete positive control over these weapons. The Navy, to meet this mission requirement, traditionally developed its systems using special purpose technology to achieve "Deterministic Control." Control system technologies are fielded in all aspects of shipboard combat systems with specific challenges in timing and safety in the surface anti-air warfare systems, the submarine launched ballistic missile systems, and air launched missile systems. Today's naval combat system is a highly complex, computer-based control system that is evolving within the framework of the commercial computer industry. This paper will briefly describe some critical and unique characteristics of a large-scale digital weapon control system and identify emerging technologies that have the potential to respond to the Navy's warfighting needs.
Health Effects of Air Pollution:\\ A Statistical Review

Summary We critically review and compare epidemiological designs and statistical approaches to estimate associations between air pollution and health. More specifically, we aim to address the following questions: 1 Which epidemiological designs and statistical methods are available to estimate associations between air pollution and health? 2 What are the recent methodological advances in the estimation of the health effects of air pollution in time series studies? 3 What are the the main methodological challenges and future research opportunities relevant to regulatory policy? In question 1, we identify strengths and limitations of time series, cohort, case-crossover and panel sampling designs. In question 2, we focus on time series studies and we review statistical methods for: 1) combining information across multiple locations to estimate overall air pollution effects; 2) estimating the health effects of air pollution taking into account of model uncertainties; 3) investigating the consequences of exposure measurement error in the estimation of the health effects of air pollution; and 4) estimating air pollution-health exposure-response curves. Here, we also discuss the extent to which these statistical contributions have addressed key substantive questions. In question 3, within a set of policy-relevant-questions, we identify research opportunities and point out current data limitations.
The HSO-SOH Isomers Revisited: The Effect of Tight d Functions†

The tight d-augmented correlation consistent basis sets, cc-pV(n+d)Z, and standard correlation consistent basis sets, cc-pVnZ, where n = D(2), T(3), Q(4), and 5, for the second-row atoms have been used to re-examine the relative energy of the HSO and SOH isomers using Hartree−Fock, coupled cluster with single and double excitation, and coupled cluster with single, double, and perturbative triple excitation levels of theory. Geometries, dissociation energies, and vibrational frequencies have also been determined for each species. The relative energies of the two isomers converge more rapidly and smoothly for the new tight d-augmented sets than for the standard sets. The impact of the tight d function is most significant upon dissociation energies at the double-ζ and triple-ζ levels for HSO, with differences of 5.46 and 2.57 kcal/mol, respectively, and less significant for SOH, with differences of 1.90 and 1.20 kcal/mol. The impact of the additional d functions in the basis set upon vibrational frequencies ...
Instance Weighting for Patient-Specific Risk Stratification Models

Accurate risk models for adverse outcomes can provide important input to clinical decision-making. Surprisingly, one of the main challenges when using machine learning to build clinically useful risk models is the small amount of data available. Risk models need to be developed for specific patient populations, specific institutions, specific procedures, and specific outcomes. With each exclusion criterion, the amount of relevant training data decreases, until there is often an insufficient amount to learn an accurate model. This difficulty is compounded by the large class imbalance that is often present in medical applications.In this paper, we present an approach to address the problem of small data using transfer learning methods in the context of developing risk models for cardiac surgeries. We explore ways to build surgery-specific and hospital-specific models (the target task) using information from other kinds of surgeries and other hospitals (source tasks). We propose a novel method to weight examples based on their similarity to the target task training examples to take advantage of the useful examples while discounting less relevant ones.We show that incorporating appropriate source data in training can lead to improved performance over using only target task training data, and that our method of instance weighting can lead to further improvements. Applied to a surgical risk stratification task, our method, which used data from two institutions, performed comparably to the risk model published by the Society for Thoracic Surgeons, which was developed and tested on over one hundred thousand surgeries from hundreds of institutions.
Adhesion characteristics of visible light-cured denture base material bonded to resilient lining materials.

Abstract This investigation compared the adhesion of resilient lining materials to Triad visible light-cured denture base material. The liners used were Tru-Soft, Molloplast-B, and Esscheem. Cylindrical samples were made from Triad VLC material and were sectioned to produce a flat bonding surface, which was roughened and treated with Triad bonding agent. Resilient liners 3 mm thick were processed according to the manufacturer's recommendations and samples were stored at 37 ° ± 1 °C in distilled water for 48 hours and 30 days. Tensile bond strength was determined by using an Instron Universal testing machine for the three resilient liners.
On the operating regimes of cocurrent upward gas—liquid—solid systems with liquid as the continuous phase

Le mouvement des particules solides est represente par trois regimes operationnels liquides et solides de base: le regime lit garnissage, le regime du lit en expansion et le regime de transport. Ces interrelations permettent de definir et de quantifier des limites pour le choix de la correlation a utiliser sans faire appel a des extrapolations
Reactivity of NH3 and HCN during low-grade fuel combustion in a swirling flow burner

Abstract The experimentally measured major gas species profiles in the near-burner region provide insight on flame structure and pollutant formation mechanisms during pilot-scale biomass, coal, and biomass-coal cofiring tests. All tests involved separately metered but jointly fed coal and biomass in a variable-swirl burner. Locally fuel-rich regions form under overall fuel-lean conditions, as is typical of such flames, although there are no regions of the combustor that indicate average oxygen concentration reaches zero. The data strongly suggest that instantaneous oxygen concentrations reach zero, so the average finite values are indicative of turbulent intermittency between fuel-rich and fuel-lean eddies. Such intermittency impacts the entire flame structure in these and many previously published flames, though this feature may not be widely appreciated. Detectable HCN concentrations appear in the fuel-rich eddies in the coal-dominated flames with little or no detectable NH3 whereas NH3 appears in the biomass-dominated flames with little or no detectable HCN. These data indicate that biomass predominantly forms NH3 whereas coal predominantly forms HCN as stable, fuel-rich, gas-phase compounds. Kinetics calculations demonstrate that NH3 has higher thermal stability and is more reactive within the flame front than HCN. Both species have similar conversion to NO at the same temperatures. The results confirm that NOx precursor formation depends on the parent fuel and form of nitrogen, at least for the coal and biomass fuels investigated here.
Parathyroid Hormone Treatment for Osteoporosis

Purpose of reviewThere has recently been a dramatic expansion of clinical investigation of parathyroid hormone (PTH). There are no other anabolic agents on the horizon at the current time but clearly there are a large number of questions that remain about this powerful agent for osteoporosis.Recent
THE CHINESE STATE ENTERPRISE: OPERATING IN A NON‐MARKET ECONOMY

The exogenous factors influencing state enterprise managerial decision making in the People's Republic of China are identified. These environmental forces are categorized as governmental and sociocultural in nature. Governmental influences are the centralized management of the economy, the dual command structure found in the Chinese state enterprises, state enterprise financing, product quality, and state enterprise production quotas. Sociocultural influences are morality, deference to authority, risk avoidance, long term view, community versus individual orientation and the legal system.
Binding of rigid dendritic ruthenium complexes to carbon nanotubes.

of the nanotube’s ends are functionalized with this large (5.8 nm), optically active, rigid supramolecular complex. We study the binding capacity with UV-vis and atomic absorption spectroscopy. Imaging the functionalized nanotubes with scanning electron microscopy and atomic force microscopy (AFM) yields direct confirmation of end functionalization. Statistical analysis of the AFM images shows the morphology of the functionalized ends is consistent with the nanotubes binding to one of the endo- or exoreceptors around the dendrimer. Implications of these results toward efficient nanomanufacturing of carbon nanotube devices are discussed.
A faster algorithm to recognize undirected path graphs

Let F be a finite family of nonempty sets. The undirected graph G is called the intersection graph of F if there is a bijection between the members of F and the vertices of G such that any two sets Fi and Fj (for i≠j) have a nonempty intersection if and only if the corresponding vertices are adjacent. We study intersection graphs where F is a family of undirected paths in an unrooted, undirected tree; these graphs are called (undirected) path graphs. They constitute a proper subclass of the chordal graphs. Gavril [Discrete Math. 23 (1978) 211–227] gave the first polynomial time algorithm to recognize undirected path graphs; his algorithm runs in time O(n4), where n is the number of vertices. The topic of this paper is a new recognition algorithm that runs in time O(mn), where m is the number of edges.
Common and specific liability to addiction: approaches to association studies of opioid addiction.

Abstract Background Opioid addiction, whether to opiates such as heroin and morphine, and/or to non-medical use of opioids, is a major problem worldwide. Although drug-induced and environmental factors are essential for the liability to develop opioid addiction, the genetic background of an individual is now known also to play a substantial role. Methods The overall goal of this article is to address the common and specific liabilities to addiction in the context of approaches to studies of one addiction, opioid addiction. Literature on identifying genetic variants that may play a role in the development of opioid addiction was reviewed. Results A substantial number of genetic variants have been reported to be associated with opioid addiction. No single variant has been found in any of the reported GWAS studies with a substantial effect size on the liability to develop heroin addiction. It appears that there is a complex interaction of a large number of variants, some rare, some common, which interact with the environment and in response to specific drugs of abuse to increase the liability of developing opioid addiction. Conclusions In spite of the inherent difficulties in obtaining large well-phenotyped cohorts for genetic studies, new findings have been reported that are being used to develop testable hypotheses into the biological basis of opioid addiction.
Primary and secondary dextrocardia. Their differentiation and the role of cineangiocardiography in diagnosing associated congenital cardiac defects.

Abstract Two cases are presented to illustrate the differential diagnosis of primary and secondary dextrocardia. As an example of the former, Case 1 demonstrated features of isolated dextrocardia without heterotaxy of other organs. Investigation revealed serious intracardiac malformations usually seen in such cases, consisting in this instance of tricuspid, atrial and ventricular septal defects, corrected transposition of the great vessels and patent ductus arteriosus. By way of contrast, Case 2 represents secondary dextrocardia as a result of congenital agenesis of the left lung. Diagnosis in this instance was established by use of bronchography. The necessity of employing a variety of radiographic technics for differentiation of primary and secondary dextrocardia is stressed, and the value of cineangiocardiography in delineating associated congenital cardiac defects is demonstrated.
The DNA-Dependent Protein Kinase Participates in the Activation of NFκB Following DNA Damage

Abstract The NFkB transcription factor is activated by diverse stimuli, including Ionizing Radiation (IR) and the cytokine TNFα. The role of DNA-PK, a protein kinase involved in the response to DNA damage, in the activation of NFκB by IR and TNFα was examined. In M059K cells, which express DNA-PK, NFκB was activated by both TNFα and IR. In M059J cells, which do not express DNA-PK, IR did not activate NFκB, whereas TNFα induction of NFκB was still observed. In HeLa cells, wortmannin, an inhibitor of DNA-PK, blocked the induction of NFκB by IR but not by TNFα. DNA-PK also phosphorylated the NFκB inhibitory proteins IkB-α and IkB-β in vitro, and deletion analysis demonstrated that DNA-PK phosphorylates 2 distinct regions of IkB-β. These results indicate that DNA-PK participates in the activation of NFκB by IR but not by TNFα.
Rethinking Layoff and Severance Benefits: A Model for Managing Layoff in Today's Workplace.

Still-rising national jobless rates are surpassing 8.9%. This translates to millions of ill-prepared job seekers, raising complex questions about how to manage layoffs. Even if workers receive severance benefits, most struggle with how to move on and find jobs. Rather than focusing primarily on work skills and practices within individual organizations, we need to rethink employment and learn to understand how to negotiate continuous changes in the work environment and in the workplace.
Stochastic analysis of a two-unit redundant system with two types of failure

Abstract The present paper investigates a stochostic model of a two-unit warm standby system with a single repair facility. Before repair, the failed unit is sent for fault detection to decide whether it failed due to machine defect or critical human error. The probability of having machine defect and C.H.E. has been fixed. Using the regenerative point technique in the Markov renewal process various measures of system effectiveness are obtained.
Macrocheilia from labial gland hyperplasia treated by plastic surgery

Summary A case of macrocheilia resulting from hyperplasia of the labial glands is reported. Cosmetic and psychologic difficulties led the patient to seek therapy. The shift in the concept of the underlying disease is discussed. The histologic picture is presented. The results of correction by plastic surgery were completely satisfactory.
Tests of proton-nucleus elastic scattering theory

Abstract Many numerical applications of the multiple scattering theories of Glauber and Kerman, McManus and Thaler have in the last few years been applied to proton elastic scattering at intermediate energies for the purpose of studying nuclear matter density distributions. The desire to describe more complicated reactions microscopically is also in evidence. Thus, the need for tests of the accuracy of the multiple scattering theories and the various approximations employed in numerical analyses is of paramount importance. Several such tests are proposed and some recent results are reviewed.
An ultraviolet spectrophotometric method for the determination of small amounts of vanadium in ores and steel

Abstract The method proposed is suitable for a quick routine determination of small amounts of vanadium in certain ores and steel. The interference of chromium in the final determination of vanadium using the ultraviolet spectra was eliminated by the use of an ion-exchange resin. Reproduceability of results was found to be acceptable for a colorimetric method.
Targeting of embryonic and postnatal autonomic and enteric neurons with a vasoactive intestinal peptide transgene.

Abstract : The neuropeptide vasoactive intestinal peptide (VIP) is expressed in several distinct sites in the CNS, in cholinergic and enteric ganglia, and in a small subpopulation of neurons within sympathetic ganglia. Previous studies on the human VIP gene indicate that transcription in neural crest-derived neuroblastoma and pheochromocytoma cell lines is controlled in part by multiple regulatory elements located along 4.5 kb of upstream 5′ flanking sequence. In the current studies, transgenic mice were created with a chimeric gene consisting of 16.5 kb of the mouse VIP gene fused to the β-galactosidase reporter. In situ hybridization analysis in adult mice indicated that reporter gene expression was correctly targeted to neurons in the esophagus, stomach, small intestine, and colon. No expression was observed in the brain, including regions that contain abundant VIP-expressing cells, such as the thalamus, amygdala, cerebral cortex, hippocampus, and suprachiasmatic nucleus. Analysis of transgene expression in neonatal and embryonic day 13.5 mice revealed a near perfect correlation between VIP and β-galactosidase gene expression in cranial cholinergic ganglia and the superior cervical ganglia, and lack of transgene expression in sensory ganglia and in nonneuronal tissue. Potential ectopic transgene expression was observed in neonates, in the cerebellar external granule layer and in a small subpopulation of neurons in the olfactory epithelium. We conclude that the 16.5 kb of VIP gene used in these studies contains sequences sufficient for directing expression specifically to VIP neurons in the PNS, and that sequences located elsewhere on the gene are required for proper CNS expression. The VIP gene sequences used here should be capable of targeting other gene products to specific populations of embryonic and adult peripheral neurons without causing significant expression in the CNS.
Reducing the risk of breast cancer.

Recent research results suggest that the risk of breast cancer can be reduced. In this review I will focus on chemoprevention, emphasizing evidence from randomized clinical trials, and in addition summarize the evidence regarding preventive strategies involving surgery and lifestyle changes (Table 1). Chemoprevention Tamoxifen and Risk Reduction The risk of breast cancer is related to levels of endogenous1,2 and exogenous3–5 hormones. Tamoxifen and raloxifene, which are selective estrogen-receptor modulators, can be used to test the hypothesis that the risk of breast cancer can be reduced by estrogen antagonists.6 Tamoxifen is active against advanced breast cancer7 and is . . .
When Good Teaching Leads to Bad Results: The Disasters of 'Well-Taught' Mathematics Courses

This article describes a case study in mathematics instruction, focusing on the development of mathematical understandings that took place in a 10-grade geometry class. Two pictures of the instruction and its results emerged from the study. On the one hand, almost everything that took place in the classroom went as intended—both in terms of the curriculum and in terms of the quality of the instruction. The class was well managed and well taught, and the students did well on standard performance measures. Seen from this perspective, the class was quite successful. Yet from another perspective, the class was an important and illustrative failure. There were significant ways in which, from the mathematician's point of view, having taken the course may have done the students as much harm as good. Despite gaining proficiency at certain kinds of procedures, the students gained at best a fragmented sense of the subject matter and understood few if any of the connections that tie together the procedures that they...
Dynamics of a Tethered Chromophore Imbedded in a Self-Assembled Monolayer

We report the first measurements on the dynamical response of alkanethiol/gold monolayers using a depth-selective tethered probe molecule technique, where 5% of the monolayer is comprised of the probe. Our transient spectroscopic data indicate that, for the first ∼10 CH 2 groups above the gold surface, the local environment is highly rigid, and from these same data, we recover an average tilt angle of 26°, in exact agreement with steady state measurements.
Classification of bacteria by pyrolysis-capillary column gas chromatography-mass spectrometry and pattern recognition

Abstract Pyrolysis followed by capillary column gas chromatography-mass spectrometry has been applied to the classification of five bacterial species of the genus Flacobacterium . Data were subjected to computerized pattern recognition using the ARTHUR software package. The results indicate that classification potential is greatly improved by the use of mass fragmentography. Other factors such as growth media, harvesting and storage conditions were found to be relatively unimportant.
Air pollution: the pathobiologic issues.

AbstractIn defining the adverse effects of ambient levels of ozone on the human lung, research has tended to emphasize direct cause and effect responses. However, disease is generally multicausative and the lung has relatively few ways to respond to injury. Moreover, all adult lungs have some disease. Thus, pathogenesis is more appropriately addressed by asking “What role does the agent in question play in the causation, promotion, facilitation, and/or exacerbation of disease that is present?” Our recent studies of the lungs of 107 ostensibly healthy youths between 14 and 25 years of age (violent death cases in Los Angeles County) add suggestive evidence to epidemiologic and experimental data indicating that air pollution is adversely affecting the human lung. We found 80% of the youths with some degree of presumably subclinical Centriacinar Region disease and, in 27%, the Centriacinar Region disease was severe and extensive. Centriacinar Region disease has been linked to infectious organisms, cigarette s...
STUDIES ON THE PARADOXICAL EFFECT OF ETHANOL ON LACTATE IN TYPE I GLYCOGENOSIS

Ethanol, by generating NADH, raises lactate levels in normals but, uniquely and paradoxically, lowers the high lactate of Type I glycogenosis patients. This phenomenon was investigated in 4 patients. The lactate/pyruvate (L/P) ratios in the patients were high, 30:1 vs. 14:1 in normals. Since the L/P relationship is expressed by the equation L = P × K NADH/NAD+, the L/P ratio, in effect, reflects the NADH/NAD+ ratio. Ethanol decreased lactate (5.3 ± 0.4 mM/L, mean ± SEM, to 2.4 ± 0.1, p < 0.02), but pyruvate fell even more (0.18 ± 0.01 mM/L to 0.03 ± .01, p < .005) thus further raising the L/P ratio (30:1 to 81:1, p < .005). This demonstrated that as in the normal, the oxidation of ethanol had generated NADH. Glucose was unchanged. The high lactate in Type I glycogenosis derives from hepatic glycogenolysis. Using a constant infusion of 14C lactate, we found that, although glycogenolysis continued, the fall in lactate, after ethanol, reflected decreased formation rather than increased utilization. The increased NADH could cause less lactate to form by diverting carbon flow to the synthesis of triglyceride. Triglyceride did rise. We conclude that the NADH/NAD+ ratio may have a critical role in the biochemical abnormalities in this disorder.
Monolithic free-space interconnects with substrate-mode holographic optical elements

In this paper the characteristics and methods of forming substrate-mode holographic optical elements are described. These components use total internal reflection to translate an optical beam, and holographic elements to couple light in and out of the guiding substrate. These gratings also have several useful polarization properties which are then discussed and demonstrated. The paper concludes with a description of the application of polarization-sensitive substrate-mode holographic elements to an optical bus system.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Correspondence between effectiveness and staff use of instructions for severely retarded persons.

Abstract While professionals and paraprofessionals working with mentally retarded persons have become involved in extraordinarily diverse areas affecting the lives of their clients, including the social, political, economic, and educational areas, the latter has received the perponderance of professional attention. Within this area, the focus of attention has typically been on the manipulation of consequences to modify the behavior of mentally retarded persons. The present study, though, examined whether staff tended to use the most effective forms of a common antecedent event (instructions) while teaching students. The findings show that the most common form of instruction (verbal instruction) was not the most effective form of instruction used by staff for nine groups of mentally retarded persons. In each cause, at least one of four other types of antecedents was more effective. Discussion centers around the appropriate identification and use of specific types of instruction for the nine subgroups of mentally retarded persons observed.
Recent advances in oscillographic polarography

Abstract The following topics in oscillographic polarography are reviewed: methods of measurement, characteristic features of oscillographic waves, the RANDLES-SEVCIK equation, the theory of the capacity current, distortions caused by the capacity current, the influence of the resistance of the measuring circuit, the influence of the anodic process in the multi-sweep method, the influence of the irreversibility of the cathodic process, and fluctuations in the drop time in the case of the multisweep method.
Nonequilibrium melting of the two dimensional electron crystal

We observe nonequilibrium melting of the two dimensional electron crystal on the surface of liquid helium. Melting is indicated by a sharp change in the magnetoresistance. The temperature and electric field at which melting occurs depends upon the applied magnetic field. A model is presented involving magnetic field induced shear melting.
Prospective Associations Among Borderline Personality Disorder Symptoms, Interpersonal Problems, and Aggressive Behaviors

This study examined the prospective relationships among borderline personality disorder (BPD) symptoms, interpersonal problems, and types of aggressive behaviors (i.e., experiencing psychological and physical victimization and perpetrating psychological and physical aggression) in a psychiatric sample (N = 139) over the course of 2 years. We controlled for other PD symptoms and demographic variables. BPD symptoms at baseline were associated with interpersonal sensitivity, interpersonal ambivalence, interpersonal aggression, need for social approval, and lack of sociability 6 months later. In turn, interpersonal sensitivity predicted not experiencing physical aggression, interpersonal aggression predicted experiencing physical aggression and perpetrating both psychological and physical aggression, need for social approval predicted experiencing both psychological and physical aggression, and lack of sociability predicted perpetrating physical aggression 2 years later. Results demonstrated that interpersonal problems mediated the relationship between BPD and later violent behaviors. Our findings suggest the importance of distinguishing between these groups of aggressive behaviors in terms of etiological pathways, maintenance processes, and treatment interventions.
Anthrax Lethal Toxin Downregulates Claudin-5 Expression in Human Endothelial Tight Junctions

Vascular leakage pathologies such as pleural effusion and hemorrhage are hallmarks of anthrax pathogenesis. We previously reported that anthrax lethal toxin (LT), the major virulence factor of anthrax, reduces barrier function in cultured primary human microvascular endothelial cells. Here, we show that LT-induced barrier dysfunction is accompanied by the reduced expression of the endothelial tight junction (TJ) protein claudin-5 but no change in the expression of other TJ components occludin, ZO-1, ZO-2, or the adherens junction (AJ) protein VE-cadherin. The downregulation of claudin-5 correlated temporally and dose-dependently with the reduction of transendothelial electrical resistance. LT-induced loss of claudin-5 was independent of cell death and preceded the appearance of actin stress fibers and altered AJ morphology. Pharmacological inhibition of MEK-1/2, two kinases that are proteolytically inactivated by LT, showed a similar reduction in claudin-5 expression. We found that LT reduced claudin-5 mRNA levels but did not accelerate the rate of claudin-5 degradation. Mice challenged with LT also showed significant reduction in claudin-5 expression. Together, these findings support a possible role for LT disruption of endothelial TJs in the vascular leakage pathologies of anthrax.
MATRIX REPRESENTATION OF POLARIZATION

The use of density matrix and Stokes parameters to describe polarization enables representation of cross sections of polarization-sensitive interactions in matrix form to be made. An extensive treatment of this representation mode is presented for photons, electrons, neutrons, and for photon-electron interactions. (D.L.C.)
Investigating faculty decisions to adopt Web 2.0 technologies: Theory and empirical tests

Abstract While students are increasing their use of emerging technologies such as text messaging, wikis, social networks, and other Web 2.0 applications, this is not the case with many university faculty. The purpose of this study was to assess faculty's awareness of the benefits of Web 2.0 to supplement in-class learning and better understand faculty's decisions to adopt these tools using the decomposed theory of planned behavior (DTPB) model. Findings indicated that while some faculty members feel that some Web 2.0 technologies could improve students' learning, their interaction with faculty and with other peers, their writing abilities, and their satisfaction with the course; few choose to use them in the classroom. Additional results indicated that faculty's attitude and their perceived behavioral control are strong indicators of their intention to use Web 2.0. A number of implications are drawn highlighting how the use of Web 2.0 could be useful in the classroom.
Zinc Concentrations in Hair, Plasma, and Saliva and Changes in Taste Acuity of Adults Supplemented with Zinc

The effect of zinc supplementation as zinc acetate (15 mg Zn/day for 5 weeks) was determined on stimulated parotid salivary zinc levels and taste acuity. In addition, zinc and copper levels of hair and plasma in 10 healthy subjects (five male and five female) between the ages of 17 and 37 years were studied. Presupplementation and 5 weeks postsupplementation levels were evaluated as well. Taste acuity for sweet improved with zinc supplementation and returned to presupplementation levels after supplementation ceased. No changes in plasma copper or salivary zinc levels were found with zinc supplementation although stimulated parotid saliva flow rate increased. Plasma zinc levels increased significantly while hair copper increased slightly with supplementation. All indices returned to presupplementation levels by 5 weeks after cessation of supplementation.
Physics based PBTI model for accelerated estimation of 10 year lifetime

Threshold voltages (V t ) in high κ nFETs are observed to shift under prolonged positive gate bias stressing. This bias induced V t shift (ΔV t ) is referred as PBTI and is an important reliability issue. In this paper, we extend a previously proposed PBTI model to include de-trapping kinetics. The proposed model is verified by comparing calculated results with PBTI data measured over a wide range of stress conditions. Using the proposed model, an accelerated method for estimating 10 year lifetime is presented. This method does not require a-priori knowledge of parameters and uses a combination of voltage ramp and constant voltage measurements to estimate model parameters with the total measurement time <; 1 hour. Using these extracted parameters and the model equations, 10 year lifetimes are estimated at different stress voltages.
Optical absorption and stimulated emission of neodymium in yttrium orthosilicate

A spectroscopic investigation of the biaxial crystal yttrium orthosilicate doped with Nd/sup 3+/(Nd/sup 3+/:Y/sub 2/SiO/sub 5/) has been performed. Spectrally and orientationally resolved emission cross sections necessary for the evaluation of laser performance on the Nd/sup 3+/ /sup 4/F/sub 3/2/-/sup 4/I/sub 9/2/ and /sup 4/F/sub 3/2-//sup 4/I/sub 11/2/ transitions have been determined. The Judd-Ofelt theory has been applied to measured values of optical absorption line strengths to obtain the orientation averaged intensity parameters: Omega /sub 2/-3.34*10/sup -20/ cm/sup 2/, Omega /sub 4/=4.35*10/sup -20/ cm/sup 2/, and Omega /sub 6/=5.60*10/sup -20/ cm/sup 2/. These Judd-Ofelt intensity parameter values are significantly different from those previously reported by A.M. Tkachuk et al. Using these intensity parameters, the Nd/sup 3+/ /sup 4/F/sub 2/ metastable state lifetime is predicted to be 225 mu s. Measured low Nd concentration /sup 4/F/sub 3/2/ lifetimes of 214 mu s indicate a high radiative quantum efficiency. Because of the Stark level splitting of the Nd/sup 3+/ /sup 4/F/sub 3/2/ and /sup 4/I/sub 9/2/ manifolds, laser operation at twice one of the Cs atomic resonance filter acceptance wavelengths is possible. >
Geospatial Information Technology, Rural Resource Development, and Future Geographies

Abstract Geospatial information technologies, particularly as they relate to remote sensing and geographic information science (GIScience) are providing new perspectives for understanding rural systems. By utilizing geospatial technologies with more integrative research approaches, geographers can ask more socially relevant and innovative questions about the human–environmental system. Within remote sensing alone, there has been a significant leap forward in usable sensor systems for analyzing human dimensions of rural areas through high spatial and spectral resolution approaches. The impact of various forcing factors (e.g., water availability) in Kansas and Botswana, for example, within the context of human–environmental interactions can be more fully understood using such geospatial technology approaches. At the same time, through new infospheres, cybergeography, and sensitivity to new attitudes in learning by millinneals, future geographies are created that demand more geographic management systems (GM...