cssi/SciSciGPT-SciSciNet huggingface dataset:
The Chinese E-Commerce Search Advertising Business: A Case Study of Taobao

Given the rapid growth of the e-commerce market in China, there is a growing need to understand the characteristics of the search advertising strategy employed by dominant e-commerce firms in China. This paper presents a case study to understand the search advertising strategy employed by Taobao based on two sample data sets obtained from the online shopping site taobao.com operated under the Chinese e-commerce giant Alibaba. The first data set contains features about the advertisements displayed after the customer’s search using keyword(s). The second data set contains features about the advertisements clicked by customers. These features and the features specific to customers such as their location, time of search, and time of clicking an advertisement in the data sets are studied to reveal insights into the online advertising strategy employed by Taobao in response to customer searches. The results of data analysis show that there is often a relationship among the variables such as the number of advertisements displayed, prices of advertised products, whether a keyword was used in the search, the time elapsed between the start of search and when an advertisement was clicked, the number of keywords used in search, the likelihood of clicking on an advertisement, and price discounts of advertised products. Specific relationships between these variables are formulated as hypothesis and then tested. The insights gained from the test results can be used to develop better business models for sponsored search advertising. Keywords: Online Search, Sponsored Search, Online Advertising, Taobao To cite this document: Joseph Richards and Min Li, "The Chinese E-Commerce Search Advertising Business: A Case Study of Taobao", Contemporary Management Research, Vol.14, No.2, pp. 121-142, 2018. Permanent link to this document: http://dx.doi.org/10.7903/cmr.18285
The Hamlin Garland Papers: Adapting Former Processing Activities to New Contexts

AbstractThe Hamlin Garland papers first came to the University of Southern California (USC) in 1940 and since then, various library staff, researchers, and student workers have applied different and sometimes conflicting processing strategies over a period of almost 80 years. In 2017, a National Historical Publications and Records Commission (NHPRC) grant made possible the digitization and description of Garland’s correspondence. This gave current USC archivists the opportunity to address some of the issues and threats facing the Garland papers, while also providing new methods of access and discovery to this valuable collection.
The Spread and Mutation of Science Misinformation

As the media environment has shifted towards digitization, we have seen the roles of creating, curating and correcting information shift from professional “gatekeeper” journalists to a broader media industry and the general public. This shift has led to the spread of misinformation. Though political “fake news” is currently a popular area of study, this study investigates another related phenomenon: science misinformation. Consistent exposure to science misinformation has been shown to cultivate false beliefs about risks, causes and prevalence of illnesses and disincentivize the public from implementing healthy lifestyle changes. Despite the need for more research, science misinformation dissemination studies are scarce. Through a case study that traces the spread of information about one specific article through hyperlink citations, this study adds valuable insights into the inner workings of media networks, conceptualizations of misinformation spread and methodological approaches to multi-platform misinformation tracing. The case study illustrates the over-reliance of media sources on secondary information and the novel phenomenon of constantly mutating online content. The original misinformant is able to remove misleading information, and as a result, all of the subsequent articles end up referencing misinformation to a source that no longer exists. This ability to update content online breaks the information flow process: news stories no longer represent a snapshot in time but instead living, mutating organisms, making any study of media networks increasingly complex.
Popular support for legislatures in Asia

Legislatures have long served as the fundamental organ of democratic rule. They bring together disparate views and competing preferences in one venue as an effort to introduce a equitable means of ...
Pseudo-topotactic growth of diamond nanofibers

Abstract We report pseudo-topotactic growth of single-crystal diamond fibers by nanosecond laser melting of amorphous carbon nanofibers (CNFs) and crystalline multi-wall carbon nanotubes (MWCNTs). A rapid laser melting in a super undercooled state and subsequent quenching convert the tips of CNFs and MWCNTs into phase-pure nanodiamonds along the growth directions. Subsequent laser pluses melt regions below nanodiamonds that provide seeds for epitaxial growth. By repeating this process, the length of nanodiamond fibers can be increased, as each pulse results in ∼50 nm nanodiamond region, depending upon the initial size of CNFs and MWCTs. This conversion process can be carried at ambient temperature and pressure in air. The epitaxial nature of nanodiamond fibers has been confirmed by systematic electron-back-scatter-diffraction studies along the fiber in high-resolution scanning electron microscopy, and high-resolution TEM imaging and diffraction. The nature of C–C bonding characteristics was studied by high-resolution electron-energy-loss spectroscopy to establish the formation of diamond phase by the characteristic peak at 292 eV for sp3 bonding (σ∗), and absence of 284 eV peak for sp2 (π∗) graphitic bonding. The characteristic diamond Raman peak at 1332 cm−1 is found to downshift to 1321 cm−1 because of phonon confinement in nanodiamonds associated with nanofibers. These nanodiamond structures can be doped with both n- and p-type dopants with concentrations far higher than thermodynamic solubility limit due to solute trapping during quenching from the liquid phase. Thus, these nanodiamond structures provide ideal platform for nanosensing, computing and communication, including efficient field emitting devices.
Applying a Bookmarking Approach to Setting Clinically Relevant Interpretive Standards for the Spinal Cord Injury: Functional Index/Capacity Basic Mobility and Self-Care Item Bank Scores

Abstract Objectives To develop clinically relevant interpretive standards for the Spinal Cord Injury – Functional Index/Capacity (SCI-FI/C) Basic Mobility and Self-Care item bank scores. Design Modified “bookmarking” standard-setting methodology, including 2 stakeholder consensus meetings with individuals with spinal cord injury (SCI) and SCI clinicians, respectively, and a final, combined (consumers and clinicians) “convergence” meeting. Setting Two SCI Model System centers in the United States. Participants Fourteen adults who work with individuals with traumatic SCI and 14 clinicians who work with individuals with SCI. Main Outcome Measures Placement of bookmarks between vignettes based on SCI-FI Basic Mobility and Self-Care T scores. Bookmarks were placed between vignettes representing “No Problems,” “Mild Problems,” “Moderate Problems,” and “Severe Problems” for each item bank. Results Each consensus group resulted in a single set of scoring cut points for the SCI-FI/C Basic Mobility and Self-Care item banks. The cut points were similar but not identical between the consumer and clinician groups, necessitating a final convergence meeting. For SCI-FI/C Basic Mobility, the convergence group agreed on cut scores of 61.25 (no problems/mild problems), 51.25 (mild problems/moderate problems), and 41.25 (moderate problems/severe problems). For SCI-FI/C Self-Care, the convergence group agreed on cut scores of 56.25 (no/mild), 51.25 (mild/moderate), and 38.75 (moderate/severe). Conclusions The results of this study provide straightforward interpretive guidelines for SCI researchers and clinicians using the SCI-FI/C Basic Mobility and Self-Care instruments. These results are appropriate for the full bank, computer adaptive test, and short-form versions of the SCI-FI/C Basic Mobility and Self-Care item banks.
Memory Reactivation during Learning Simultaneously Promotes Dentate Gyrus/CA2,3 Pattern Differentiation and CA1 Memory Integration.

Events that overlap with previous experience may trigger reactivation of existing memories. However, such reactivation may have different representational consequences within the hippocampal circuit. Computational theories of hippocampal function suggest that dentate gyrus and CA2,3 (DG/CA2,3) are biased to differentiate highly similar memories, whereas CA1 may integrate related events by representing them with overlapping neural codes. Here, we tested whether the formation of differentiated or integrated representations in hippocampal subfields depends on the strength of memory reactivation during learning. Human participants of both sexes learned associations (AB pairs, either face-shape or scene-shape), and then underwent fMRI scanning while they encoded overlapping associations (BC shape-object pairs). Both before and after learning, participants were also scanned while viewing indirectly related elements of the overlapping memories (A and C images) in isolation. We used multivariate pattern analyses to measure reactivation of initial pair memories (A items) during overlapping pair (BC) learning, as well as learning-related representational change for indirectly related memory elements in hippocampal subfields. When prior memories were strongly reactivated during overlapping pair encoding, DG/CA2,3 and subiculum representations for indirectly related images (A and C) became less similar, consistent with pattern differentiation. Simultaneously, memory reactivation during new learning promoted integration in CA1, where representations for indirectly related memory elements became more similar after learning. Furthermore, memory reactivation and subiculum representation predicted faster and more accurate inference (AC) decisions. These data show that reactivation of related memories during new learning leads to dissociable coding strategies in hippocampal subfields, in line with computational theories. SIGNIFICANCE STATEMENT The flexibility of episodic memory allows us to remember both the details that differentiate similar events and the commonalities among them. Here, we tested how reactivation of past experience during new learning promotes formation of neural representations that might serve these two memory functions. We found that memory reactivation during learning promoted formation of differentiated representations for overlapping memories in the dentate gyrus/CA2,3 and subiculum subfields of the hippocampus, while simultaneously leading to the formation of integrated representations of related events in subfield CA1. Furthermore, memory reactivation and subiculum representation predicted success when inferring indirect relationships among events. These findings indicate that memory reactivation is an important learning signal that influences how overlapping events are represented within the hippocampal circuit.
NATURAL HISTORY AND PREDICTORS OF VISION LOSS IN EYES WITH DIABETIC MACULAR EDEMA AND GOOD INITIAL VISUAL ACUITY.

PURPOSE To identify clinical and anatomic factor-associated vision loss in eyes with treatment-naive diabetic macular edema and good initial visual acuity. METHODS Retrospective cohort study after long-term history of eyes with untreated center-involving diabetic macular edema and baseline visual acuity ≥ 20/25 seen at the University of California, Davis Eye Center between March 2007 and March 2018. We collected characteristics including diabetes type, hemoglobin A1c, presence of visual symptoms, visual acuity, and diabetic retinopathy severity; and spectral-domain optical coherence tomography biomarkers including central subfield thickness, intraretinal cyst size, intraretinal hyperreflective foci, disorganization of retinal inner layers, and outer layer disruptions to determine factors associated with vision loss as defined by DRCR Protocol V as threshold for initiating aflibercept therapy. RESULTS Fifty-six eyes (48 patients) with untreated diabetic macular edema and mean baseline visual acuity of logMAR 0.05 ± 0.05 (Snellen 20/22) were followed for an average of 5.1 ± 3.3 years, with a median time to vision loss of 465 days (15 months). Older age (hazard ratio [HR] 1.04/year, P = 0.0195) and eyes with severe NPDR (HR 3.0, P = 0.0353) or proliferative diabetic retinopathy (HR 7.7, P = 0.0008) had a higher risk of a vision loss event. None of the spectral-domain optical coherence tomography biomarkers were associated with vision loss except central subfield thickness (HR 0.98, P = 0.0470) and cyst diameter (HR 1.0, P = 0.0094). CONCLUSION In eyes with diabetic macular edema and good initial vision, those with older age and worse diabetic retinopathy severity should be monitored closely for prompt treatment initiation when vision loss occurs.
Assessing the Effects of COVID-19 on Romantic Relationships and the Coping Strategies Partners Use to Manage the Stress of a Pandemic

As a result of the COVID-19 pandemic, romantic partners and families were forced to develop new routines under increasingly stressful circumstances. These conditions had the potential to introduce ...
Chaos Theory in the Chaotic Marketplace: Re-examining Marketplace Theory in the Networked Era

The marketplace metaphor’s meaning has never been static. Enlightenment-based assumptions about truth and rationality justices installed into the theory’s foundations have been criticized by scholars and, in the networked era, are becoming more suspect. Chaos theory provides a lens through which to revise marketplace theory. Chaos theory identifies that Enlightenment-era positivistic, reductionist thinking leaves unaccounted for variables and does not allow for linear outcomes. A chaos-infused marketplace accounts for human diversity and revises truth assumptions.
Stock-Option Financing in Pre-IPO Companies

In this Closer Look, we examine a new industry that has arisen in recent years to facilitate the financing of stock-option exercises for employees and executives of pre-IPO companies. These capital providers allow individuals to exercise and retain their stock option awards, meaning the employee can continue to participate in any future appreciation of the shares while still receiving the money needed to exercise the award, pay taxes, and in some cases extract additional capital to finance personal expenditures. We consider the economic implications of this market from the perspectives of employees and employers, as well as the financial model of the capital providers that participate in this space. We ask: • For which employees does stock-option financing make sense? • Is the growth of this industry driven by large increases in private company valuations, or would it continue in the absence of these forces? • Why haven’t more traditional lenders entered the market? Would more competition drive down lending rates and the returns these vendors enjoy? • What impact does early exercise of stock options have on incentive programs?
The Effect of Predator Competition on the Stability of Sea Star - Mussel Population Dynamics

Experimental evidence has shown that the ochre sea star (Pisaster ochraceus) is capable of a developmental response to an increase in mussel biomass. This plasticity of growth allows sea stars to increase in size which, in turn, enhances their mussel feeding rate. A developmental response allows sea stars to stabilize a fast-growing mussel population. This article presents a deterministic model based on energy flow mechanisms that simulates the effect of predator competition for prey on the predatory developmental response. Predator competition was simulated by considering scenarios consisting of different sea star densities. The model predicted that a low sea star density will lead to: 1) a high abundance of mussels regardless of the initial average sea star size, and 2) a large average predator size due to the low competition for prey. The model predicts a significant reduction in average sea star size if sea star density increases, if mussel density is low, or if the mussels are of a small size. These results are consistent with empirical evidence which shows that sea stars can shrink in order to survive in an environment that does not provide the necessary energy to sustain their growth. Bifurcation analysis identified a value of predator density below which sea star-mussel coexistence is possible, and above which mussels can escape predation and their density grows to the carrying capacity of the environment.
Radiolabeled Antibodies for Therapy of Infectious Diseases

Novel approaches to the treatment of infectious diseases are urgently needed. This need has resulted in renewing the interest in antibodies for therapy of infectious diseases. Radioimmunotherapy (RIT) is a cancer treatment modality that utilizes radiolabeled monoclonal antibodies. During the last decade we have translated RIT into the field of experimental fungal, bacterial, and HIV infections. In addition, successful proof of principle experiments with radiolabeled pan-antibodies that bind to antigens shared by major pathogenic fungi have been performed in vitro. The armamentarium of pan-antibodies would result in reducing our dependence on microorganism-specific antibodies and thus would speed up the development of RIT for infections. We believe that the time is ripe for deploying RIT in the clinic to combat infectious diseases.
State Information in Bayesian Games

Two-player zero-sum repeated games are well understood. Computing the value of such a game is straightforward. Additionally, if the payoffs are dependent on a random state of the game known to one, both, or neither of the players, the resulting value of the game has been analyzed under the framework of Bayesian games. This investigation considers the optimal performance in a game when a helper is transmitting state information to one of the players. Encoding information for an adversarial setting (game) requires a different result than rate-distortion theory provides. Game theory has accentuated the importance of randomization (mixed strategy), which does not find a significant role in most communication modems and source coding codecs. Higher rates of communication, used in the right way, allow the message to include the necessary random component useful in games.
Chapter 6 Glycoproteins in inflammatory bowel disease

Publisher Summary Idiopathic inflammatory bowel disease, including Crohn's disease and ulcerative colitis, involve most frequently the terminal ileum and colon. An important component of the normal colon that serves to maintain its integrity is the dense layer of glycoproteins that coats the colonic surface. Structural changes of colonic mucin glycoproteins in association with idiopathic inflammatory bowel disease have been demonstrated using a broad range of approaches including chromatographic separation based on size or ionic charge, biochemical structural analyses, immunological and histochemical assays. In addition to changes in the glycan structures of glycoproteins in the colonic mucus, structural changes were also detected in serum immunoglobulin G (IgG) from patients with inflammatory bowel disease. These changes are characterized by an increased proportion of IgG structures lacking D-galactose (Gal) [l l-13]. This abnormality was more frequently detected in Crohn's disease than in ulcerative colitis. Furthermore, while the Gal deficiency of IgG was found to be proportional with the severity of disease in Crohn's disease, no such relationship was detected in ulcerative colitis.
Smart pixel devices and free-space digital optics applications

We have investigated optoelectronic techniques for transferring the 2D output pages of a volume optical memory to a much smaller number of spatially parallel optical or electronic output lines, each operating at a very high data rate. The smart pixel detector array converts the data to electronic form, performs error correction and formatting, and transmits it in parallel optoelectronic form for input to a network or transfer to another storage device or processor. We are designing these smart pixel systems.
Direct reduction of antigen receptor expression in polyclonal B cell populations developing in vivo results in light chain receptor editing

Secondary Ab V region gene segment rearrangement, termed receptor editing, is a major mechanism contributing to B lymphocyte self-tolerance. However, the parameters that determine whether a B cell undergoes editing are a current subject of debate. We tested the role that the level of BCR expression plays in the regulation of receptor editing in a polyclonal population of B cells differentiating in vivo. Expression of a short hairpin RNA for κ L chain RNA in B cells resulted in reduction in levels of this RNA and surface BCRs. Strikingly, fully mature and functional B cells that developed in vivo and efficiently expressed the short hairpin RNA predominantly expressed BCRs containing λ light chains. This shift in L chain repertoire was accompanied by inhibition of development, increased Rag gene expression, and increased λ V gene segment-cleavage events at the immature B cell stage. These data demonstrated that reducing the translation of BCRs that are members of the natural repertoire at the immature B cell stage is sufficient to promote editing.
Racismo Epistémico, Islamofobia Epistémica y Ciencias Sociales Coloniales

Este articulo trata sobre la manera como el racismo epistemico configura las discusiones actuales sobre la islamofobia. La primera parte es una discusion sobre el racismo epistemico en el sistema-mundo. La segunda aborda la politica identitaria hegemonica masculina en Occidente y las respuestas fundamentalistas que se le han dado. La tercera tiene que ver con la islamofobia epistemica y las ciencias sociales occidental-coloniales
Comparisons of substance abuse, high-risk sexual behavior and depressive symptoms among homeless youth with and without a history of foster care placement.

AbstractAims and objectives: The purpose of this study was to compare prevalence of substance use, high-risk sexual behaviors, and depression symptoms between homeless youth with and without a history of foster care placement. Background: Approximately 26,000 young persons exit foster care annually in the United States. Once they ‘age out’ of foster care, however, many young persons do not have access to comprehensive health care. They also are at risk for substance abuse, homelessness, or mental illness. Because persons with a history of foster care are at risk for negative psycho-social outcomes, it is unclear if these young people might be different than homeless youth without this history. Design: The design is descriptive and cross-sectional. Methods: A total of 156 homeless young persons, of whom 44 had a history of foster care placement, were recruited from a drop-in center that caters to homeless youth and young adults. Results: The sample was majority male and white; ages were 16–25. Significantl...
Preventing "the needless peril of the coal mine": the Bureau of Mines and the campaign against coal mine explosions, 1910-1940.

De 1906 a 1910, de nombreux mineurs moururent aux Etats-Unis a cause d'explosions dans les mines. Des etudes scientifiques effectuees par des geologues demontrerent que la poussiere de charbon etait tres explosive. Des mesures preventives, soutenues par le Bureau des Mines, s'imposerent alors afin de reduire la perte des ressources et des hommes
Mate desertion and reproductive effort in the snail kite

Trivers' (1972) mate desertion model was tested by relating measures of reproductive effort for snail kites, Rostrhamus sociabilis, to the sex of the deserting parent. Deserters incubated, brooded and chased potential predators as frequently as did non-deserting mates. Only provisioning of nestlings differed significantly between deserters and their mates, correctly predicting which individual deserted at all nests. Reduced feeding by deserters became established within the first 2 weeks after hatching. Cluster analysis sorted three of four nests deserted by males into one cluster and the other male-deserted nest, which was deserted later in the nesting cycle than all others, clustered with non-deserting nests. Daily energy expenditure was measured throughout the nesting cycle to estimate reproductive effort: at three of four nests, deserters expended less energy than their mates prior to desertion, but in one case, cumulative energy investments did not predict which mate should have deserted. Differences in reproductive effort between mates may have predicted which mate deserted because (1) cumulative reproductive effort is a good indicator of the costs and benefits of desertion, and (2) deserters may assess the potential for deserting by testing their mate's abilities to care for the young. The influence of other factors affecting the costs and benefits of mate desertion decisions by snail kite parents is also discussed.
Force and myosin light chain phosphorylation in dog airway smooth muscle activated in different ways

To assess activation mechanisms of dog trachealis muscle and test whether isometric force generation could be separated from myosin light-chain (MLC) phosphorylation, force and phosphorylation were measured in the presence of wortmannin (a light-chain kinase inhibitor) or Y-27632 (a rho-kinase inhibitor) during electrically stimulated tetani and sustained contractures induced by acetylcholine, KCl, or calyculin A, a light-chain phosphatase inhibitor which caused irreversible contractures and both di- and mono-phosphorylation of light chain. Phosphorylation was not much more than half under any circumstances. A nearly constant proportionality between steady force and phosphorylation existed over a 9-fold force range during contractures and 25-sec tetani, except that force correlated best with the di-phosphorylated light chain produced by calyculin A. Phosphorylation was disproportionately higher than force at the outset of tetani, and this disproportion was exaggerated by Y-27632. The results suggest that about half the light chain is sequestered from kinases and that mechanical activation is tightly linked to phosphorylation, except at the outset of stimulation.
Does music instruction improve fine motor abilities

The fine motor abilities of children who participated in two years of piano instruction and those who had never received formal music training were compared before and after the instruction. A significant improvement in fine motor skills was found only for the children who received the lessons, and a significant difference in the speed of response was found between the two groups at the end of the two years of instruction. The innumerable opportunities to assess, refine, and time their motor responses to specific stimuli during musical practice and the availability of constant evaluative feedback (i.e., sound) may allow musicians to improve the accuracy and speed of perceiving and responding to relevant stimuli.
Stimulation of Pancreatic Growth by Cholecystokinin Is Mediated by High-Affinity Receptors on Rat Pancreatic Acinar Cells

Abstract Pancreatic acinar cells possess both high and low affinity receptors for cholecystokinin. The cholecystokinin analog caerulein, which exerts a trophic effect on the rat pancreas, acts as an agonist at both types of receptors. In contrast, the synthetic analog CCK-JMV-180, which also acts as an agonist at high affinity receptors, opposes the action of caerulein on the low affinity receptors. We report that infusion of either caerulein or CCK-JMV- 180 into rats increases [3H]-thymidine incorporation into pancreatic DNA and causes the pancreatic weight as well as content of DNA, RNA, and protein to increase. CCK-JMV-180 also stimulates in-vitro incorporation of [3H]-thymidine into DNA of cultured rat acini. The finding that both caerulein and CCK-JMV-180 exert the same trophic effect on pancreatic acinar cells indicates that this effect is mediated via high affinity acinar cell cholecystokinin receptors.
Public Administrators’ Use of Social Media Platforms Overcoming the Legitimacy Dilemma?

Previous research incorporates Habermas’ theory of communicative action with implications of social media for public discourse, yet few studies consider the theory’s relevance and applicability to ...
MASS TRANSFER AND POLARIZATION AT A ROTATING DISK ELECTRODE

Abstract Measured limiting currents for deposition of copper on a rotating copper disk from aqueous copper sulphate solutions are found to agree satisfactorily with values calculated with consideration of the concentration dependence of the physical properties of the solution. The observed electrode polarization can be traced mainly to the ohmic potential drop in these solutions of low electrical conductivity.
Role of the C-terminal G3 domain in sorting and secretion of aggrecan core protein and ubiquitin-mediated degradation of accumulated mutant precursors.

Aggrecan is a complex multidomain macromolecule that undergoes extensive processing and post-translational modification. A thorough understanding of the events and signals that promote translocation of aggrecan through the secretory pathway is lacking. To investigate which features of the C-terminal G3 region are necessary for successful translocation of the core protein, a number of deletion constructs based on the chick aggrecan cDNA sequence were prepared and transiently expressed in COS-1 cells and the natural host, embryonic chick chondrocytes; stable cell lines were established as well. The present results clearly establish a precise requirement for that portion of the G3 C-lectin domain encoded by exon 15 for: (i) translocation from the endoplasmic reticulum (ER) to the Golgi, (ii) secretion from the cell, (iii) galactosylation of chondroitin sulfate (CS) chains, (iv) generation of Ca+2-dependent galactose binding ability. Furthermore, in the absence of this subdomain there is excess accumulation in the ER of expression products leading to a stress-related response involving the chaperones Grp78 and protein disulfide isomerase, followed by degradation via a ubiquitin-proteosome pathway. All of these events in the model system faithfully mimic the naturally occurring nanomelic mutant, which also elicits a ubiquitin-mediated degradation response due to the accumulation of the truncated core protein precursor. This study represents the first report of the mode of degradation of overexpressed or misfolded proteoglycans and suggests that, although proteoglycans follow different glycosylation pathways from other glycoproteins, they are monitored by an ER surveillance system similar to that which detects other misfolded proteins.
Irritable bowel syndrome.

Patients with different irritable bowel symptoms and normal subjects were compared to determine whether subtypes of irritable bowel syndrome (IBS) could be distinguished on the basis of colonic motility or psychological test scores. A provocative test involving stepwise distension of the rectosigmoid area revealed two types of colonic motility. Slow contractions having durations of at least 15 sec and occurring at irregular intervals were more frequent in IBS patients than in normals but did not differentiate constipation from diarrhea. Fast contractions having durations of less than 15 sec and occurring in runs at frequencies of 6–9 cpm were more frequent in patients with diarrhea than in normals or constipated IBS patients. Constipated patients showed no more fast contractions than normals. Severity of bowel symptoms was correlated with the overall amount of motility (motility index) in patients with diarrhea but not in patients with constipation. Patients with IBS showed significantly elevated levels on the following psychological traits: anxiety, interpersonal sensitivity, depression, hostility, and somatization of affect. However, there were no significant trait differences between patients with diarrhea and those with constipation. Also, there was no correlation between amount of psychopathology and either colonic motility or severity of symptoms in the whole group of IBS patients.
Assessment of Urologists' Practice Preferences for the Management of Benign Prostatic Hyperplasia in the Veterans Administration Program

Abstract Objective: The goal of this study was to assess diagnostic and treatment modality preferences of urologists for the management of benign prostatic hyperplasia (BPH) in the Veterans Administration (VA) patient population. Methods: A self-administered mail survey was sent to 294 urologists who provide services to the VA population in 149 VA medical centers across the United States. The survey contained descriptions of simulated BPH cases, for which the urologists were asked to indicate their preferences in diagnostic tests and treatment options. The survey also gathered information on the frequency of failed initial therapy and demographic and practice information. A nonresponse survey was conducted to estimate nonresponse bias. Results: The response rate was 39.0%. There were no significant differences between nonrespondents and respondents on selected important demographic and practice variables. Respondents generally selected practices that were consistent with clinical guidelines for recommended tests, but their preferences for optional tests varied. Alpha-blockers were the most preferred treatment option, regardless of disease severity. The second most preferred option in mild BPH was watchful waiting, whereas in both the moderate and severe cases it was transurethral resection of the prostate. The respondents reported a treatment failure rate of 41.1%. The most common switch in therapy was from alpha-blockers to surgery. Urologists were in moderate agreement in terms of their preference for diagnostic tests and in substantial agreement on treatment preferences. Conclusions: This study provides insight into the preferences of VA urologists regarding the diagnosis and management of BPH. However, the results need to be validated by assessment of the VA clinical records of actual new patients with BPH.
Cation-dependent prolactin activation of guanylate cyclase.

Summary Prolactin enhanced guanylate cyclase [E.C.4.6.1.2]two- to threefold in ovary, testis, mammary gland, liver and kidney. Dose response relationships revealed that maximal activation of this enzyme was at a concentration of one nanomolar and that increasing prolactin's concentration to the millimolar range caused no further increase in activity. There was an absolute cation requirement for prolactin's enhancement of guanylate cyclase. Calcium or manganese allowed prolactin to increase guanylate cyclase activity. Greater enhancement of this enzyme's activity by prolactin was observed when manganese was the co-factor. The data in this investigation suggest that guanylate cyclase may play a role in the mechanism of action of prolactin.
Halo formation in intense electron beams in high-power klystron amplifiers

An important issue in the design of high-power microwave sources is how to prevent high-intensity relativistic electron beams from forming halos because they cause electron beam losses and radio-frequency pulse shortening. In this paper, we study the behavior of a high-intense electron beam under a current-oscillation-induced mismatch between the beam and the magnetic focusing field, using a 2D self-consistent electrostatic model. For high-intensity electron beams, it is found from the self-consistent simulations that sizable halos appear after the beam envelope undergoes several mismatched oscillations, depending on the amplitude of mismatched beam envelope oscillations. Detailed simulation results are presented for the choice of system parameters corresponding to the 50 MW, 11.4 GHz periodic permanent magnetic focusing klystron experiment at the Stanford Linear Accelerator Center. Moreover, it is found that the process of halo formation in a uniform-solenoidal focusing klystron is essentially the same as in the PPM focusing klystron with comparable system parameters.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Mutants of the visual pathway of Drosophila melanogaster.

WITH the objective of analysing visual processes, we have attempted to generate mutants of Drosophila melanogaster with single-step lesions on the genes controlling the visual pathway1. One of these (x-7) had an abnormal electroretinogram (ERG) consisting apparently of responses from the photoreceptor layer alone. Similar ERGs could be obtained from the mutants tan1,2 and ebony2. Indeed, the mutants x-7 and tan seemed to be allelic1. We now have new mutants, and ERG characteristics suggest genetic blocks in the visual pathway of several of them.
Nano-dispersed Particulate Ceramics in Poly-Lactide-Co-Glycolide Composites Improve Implantable Bone Substitute Properties

Metallic materials widely used in orthopedic applications have much stronger mechanical properties (such as elastic modulus) than natural bone, which can weaken the newly formed bone interface due to stress-shielding. Because natural bone is under continuous physiological stresses (such as compression, tension, torsion, and/or bending), the mechanical properties of orthopedic implant materials should closely match those of living bone. This is necessary to minimize stress and strain imbalances during physiological loading conditions which will lead to implant failure. The objective of the present study was to characterize the mechanical properties of PLGA with well-dispersed nanophase titania. The dispersion of titania in PLGA was controlled by sonication and was characterized by field emission scanning electron microscopy and image analysis. For this purpose, two major stresses (compression and tension) that natural bone experiences under physiological loading conditions were characterized using an Instron Material Testing System. The results showed that nano-dispersed titania particles in PLGA increased the compressive and tensile modulus of such scaffolds compared to pure PLGA scaffolds and the more agglomerated ceramics in PLGA scaffolds. The mechanisms behind these results were also speculated. Since the predominant feature of nano-particles lies in their ultra-fine dimension, a large fraction of filler atoms can reside at the PLGA-ceramic interface which can lead to a stronger interfacial interaction, but only if the nano-particles are well dispersed at the nanometer level in the surrounding polymer matrix. As the interfacial PLGA-ceramic structure plays a critical role in determining the mechanical properties of composites, nano-composites with a great number of smaller interfaces could be expected to provide unusual properties, and the shortcomings induced by the heterogeneity of conventional (or micron) particle filled composites would also be avoided. Therefore, coupled with prior studies demonstrating greater osteoblast functions, the combination of PLGA with a strong and biocompatible well-dispersed nano-ceramic phase may provide better candidate materials for orthopedic applications.
Solid-state optical coupling for surface plasmon resonance sensors

An optical coupling methodology using a removable and strippable polymer is reported. Poly(dimethylsiloxane) films (PDMS) are used to bond two optical components and are compared to the coupling provided by conventional refractive index matching oils and gels. The detection limit and sensitivity of the solid-state PDMS coupled optical components are investigated, using a commercially available surface plasmon resonance (SPR) instrument. Films are prepared either by an in situ curing of the PDMS pre-polymer and cast between the prism and the gold-coated glass slide of an SPR sensor or using a self standing thin film of pre-cured PDMS sandwiched between the two optical components. Both approaches lead to an efficient optical and mechanical coupling. The PDMS films may be stripped and removed very easily from the optical component surfaces after usage, due to their very low surface adhesion characteristics, reducing the messiness of the conventional optical oils and gels. The response of the PDMS-coupled SPR sensors is validated with calibration curves for both increasing sucrose and ethanol/water mass fractions. This work presents the first application of an all solid-state polymer film as an optical coupling medium in SPR and may find applications in other optical networks.
Discovery of cross-tie walls at saw-tooth magnetic domain boundaries in permalloy films

Scanning electron microscopy with polarization analysis was used to image the surface magnetic domain structure of permalloy films (350 A Ni83Fe17) in ultrahigh vacuum. These thin-film materials are used in a variety of magnetoresistive sensing applications, which depend on the state of the domains present in the film. In the demagnetized state of the films, saw-tooth domain boundaries separating two large approximately head-on domains were observed. At high magnification, cross-tie walls were seen with a periodic vortex structure along the straight edges of the saw-tooth domain boundaries.
A Parsimonious Model for Gene Regulation by miRNAs

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) act with the Argonaute family of proteins to regulate target messenger RNAs (mRNAs) posttranscriptionally. SiRNAs typically induce endonucleolytic cleavage of mRNA with near-perfect complementarity. For targets with less complementarity, both translational repression and mRNA destabilization mechanisms have been implicated in miRNA-mediated gene repression, although the timing, coupling, and relative importance of these events have not been determined. Here, we review gene-specific and global approaches that probe miRNA function and mechanism, looking for a unifying model. More systematic analyses of the molecular specificities of the core components coupled with analysis of the relative timing of the different events will ultimately shed light on the mechanism of miRNA-mediated repression.
TIME‐GCM study of the ionospheric equatorial vertical drift changes during the 2006 stratospheric sudden warming

This modeling study quantifies the daytime low-latitude vertical E×B drift changes in the longitudinal wave number 1 (wn1) to wn4 during the major extended January 2006 stratospheric sudden warming (SSW) period as simulated by the National Center for Atmospheric Research thermosphere-ionosphere-mesosphere electrodynamics general circulation model (TIME-GCM), and attributes the drift changes to specific tides and planetary waves (PWs). The largest drift amplitude change (approximately 5 m/s) is seen in wn1 with a strong temporal correlation to the SSW. The wn1 drift is primarily caused by the semidiurnal westward propagating tide with zonal wave number 1 (SW1), and secondarily by a stationary planetary wave with zonal wave number 1 (PW1). SW1 is generated by the nonlinear interaction of PW1 and the migrating semidiurnal tide (SW2) at high latitude around 90–100 km. The simulations suggest that the E region PW1 around 100–130 km at the different latitudes has different origins: at high latitudes, the PW1 is related to the original stratospheric PW1; at midlatitudes, the model indicates PW1 is due to the nonlinear interaction of SW1 and SW2 around 95–105 km; and at low latitudes, the PW1 might be caused by the nonlinear interaction between DE2 and DE3. The time evolution of the simulated wn4 in the vertical E×B drift amplitude shows no temporal correlation with the SSW. The wn4 in the low-latitude vertical drift is attributed to the diurnal eastward propagating tide with zonal wave number 3 (DE3), and the contributions from SE2, TE1, and PW4 are negligible.
Multiple-Level Organization of a Great Railroad

Concluding his sophisticated analysis of the Pennsylvania Railroad's organizational structure (cf. BUSINESS HISTORY REVIEW, Summer, 1961), the anonymous reporter for the RAILROAD GAZETTE described in a supplementary article, reproduced here following Professor Jenks' interpretative comments, the decentralized management of the Pennsylvania's western divisions.
Enhanced benzene formation on Pt/H-mordenite and Pd/H-mordenite

The distribution of methylcyclopentane (MCP) ring enlargement (RE) products between benzene (Bz) and cyclohexane (CH) provides information on the reaction mechanism. The Bz/CH ratio is in excess of the calculated and experimentally determined equilibrium ratio. This implies that benzene is a primary product; it eliminates the possibility of direct hydride ion transfer to carbenium ions as the prevailing mechanism. The results are consistent with the concept that metal-proton adducts are instrumental in bifunctional catalysis.
Biotic and abiotic immobilization of ammonium, nitrite, and nitrate in soils developed under different tree species in the Catskill Mountains, New York, USA

Nitrogen retention in soil organic matter (SOM) is a key process influencing the accumulation and loss of N in forest ecosystems, but the rates and mechanisms of inorganic N retention in soils are not well understood. The primary objectives of this study were to compare ammonium (NH4 1 ), nitrite (NO2 � ), and nitrate (NO3 � ) immobilization among soils developed under different tree species in the Catskill Mountains of New York State, and to determine the relative roles of biotic or abiotic processes in soil N retention. A laboratory experiment was performed, where 15 N was added as NH4 1 ,N O2 � ,o r NO3 � to live and mercury-treated O horizon soils from three tree species (American beech, northern red oak, sugar maple), and 15 N recoveries were determined in the SOM pool. Mercuric chloride was used to treat soils as this chemical inhibits microbial metabolism without significantly altering the chemistry of SOM. The recovery of 15 N in SOM was almost always greater for NH4 1 (mean 20%) and NO2 � (47%) than for NO3 � (10%). Ammonium immobilization occurred primarily by biotic processes, with mean recoveries in live soils increasing from 9% at 15min to 53% after 28 days of incubation. The incorporation of NO2 � into SOM occurred rapidly (o15min) via abiotic processes. Abiotic immobilization of NO2 � (mean recovery 58%) was significantly greater than abiotic immobilization of NH4 1 (7%) or NO3 � (7%). The incorporation of NO2 � into SOM did not vary significantly among tree species, so this mechanism likely does not contribute to differences in soil NO3 � dynamics among species. As over 30% of the 15 NO2 � label was recovered in SOM within 15min in live soils, and the products of NO2 � incorporation into SOM remained relatively stable throughout the 28-day incubation, our results suggest that NO2 � incorporation into SOM may be an important mechanism of N retention in forest soils. The importance of NO2 � immobilization for N retention in field soils, however, will depend on the competition between incorporation into SOM and nitrification for transiently available NO2 � . Further research is required to determine