cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface barriers and surface conductance

Synopsis A brief review is given of the effect of a space-charge barrier layer at the free surface of a semiconductor on various properties: (1) contact potential, (2) change in contact potential with illumination, (ΔC.P.) L , (3) rectification, (4) electron transfer reactions, including adsorption, (5) surface life-time and photo conductivity, (7) surface conductance, including the channel effect in NPN transistors, (8) effect of an external transverse electric field on surface conductance (field effect). Recent measurements made at Illinois of changes of surface conductance of germanium with ambient are described. Ambients were changed in a cycle similar to that used by Brattain: sparked O 2 , dry O 2 , wet O 2 , dry O 2 . These measurements combined with calculations of surface conductance by J. R. Schrieffer enable one to estimate the height of the surface barrier and the way the height changes with ambient. Changes of the order of 0.3 eV are found. An inversion layer of p -type conduction on an n -type sample is frequently observed with sparked O 2 and dry O 2 . Simultaneous measurements of photoconductivity, (ΔC.P.) L , and of the field effect enable one to correlate these quantities with the barrier. The field effect changes sign when the surface conductance is a minimum. Effective mobility of the induced charge is less than the theoretical maximum.
Hybrid atrial fibrillation ablation via direct right atrial approach: first-ever case.

A 60-year-old female with persistent atrial fibrillation (AF) and flutter was referred for hybrid AF ablation. She had an occluded inferior vena cava filter from a history of deep vein thrombosis and pulmonary embolism. Via a right mini-thoracotomy, the pericardium was accessed …
THE LAPAROSCOPIC BOARI FLAP

Purpose: Laparoscopic management of ureteral pathologies, such as ureteropelvic junction obstruction, ureteral calculi and retroperitoneal fibrosis, has proved to be highly effective. We present our initial experience with the laparoscopic Boari flap in regard to feasibility, safety and short-term results.Materials and Methods: Three patients who presented with distal ureteral obstruction underwent preoperative radiographic evaluation, including excretory urography, computerized tomography and retrograde pyelography, that showed upper urinary tract dilatation at the site of obstruction. The contralateral upper urinary tract was normal in all cases. Ureteroureterostomy and ureteroneocystostomy was not feasible because of stricture length and a laparoscopic Boari flap procedure was performed. Renal function, symptom improvement and radiological studies, including excretory urography and cystography, were assessed 3 and 6 months postoperatively.Results: All procedures were successfully performed without any ...
p204 Is Required for the Differentiation of P19 Murine Embryonal Carcinoma Cells to Beating Cardiac Myocytes ITS EXPRESSION IS ACTIVATED BY THE CARDIAC GATA4, NKX2.5, AND TBX5 PROTEINS

Among 10 adult mouse tissues tested, the p204 protein levels were highest in heart and skeletal muscle. We described previously that the MyoD-inducible p204 protein is required for the differentiation of cultured murine C2C12 skeletal muscle myoblasts to myotubes. Here we report that p204 was also required for the differentiation of cultured P19 murine embryonal carcinoma stem cells to beating cardiac myocytes. As shown by others, this process can be triggered by dimethyl sulfoxide (DMSO). We established that DMSO induced the formation of 204RNA and p204. Ectopic p204 could partially substitute for DMSO in inducing differentiation, whereas ectopic 204 antisense RNA inhibited the differentiation. Experiments with reporter constructs, including regulatory regions from the Ifi204 gene (encoding p204) in P19 cells and in cultured newborn rat cardiac myocytes, as well as chromatin coimmunoprecipitations with transcription factors, revealed that p204 expression was synergistically transactivated by the cardiac Gata4, Nkx2.5, and Tbx5 transcription factors. Furthermore, ectopic p204 triggered the expression of Gata4 and Nkx2.5 in P19 cells. p204 contains a nuclear export signal and was partially translocated to the cytoplasm during the differentiation. p204 from which the nuclear export signal was deleted was not translocated, and it did not induce differentiation. The various mechanisms by which p204 promoted the differentiation are reported in the accompanying article (Ding, B., Liu, C., Huang, Y., Yu, J., Kong, W., and Lengyel, P. (2006) J. Biol. Chem. 281, 14893-14906).
Numerical simulation of hypersonic inlet flows with equilibrium or finite rate chemistry

An efficient numerical program incorporated with comprehensive high temperature gas property models has been developed to simulate hypersonic inlet flows. The computer program employs an implicit lower-upper time marching scheme to solve the two-dimensional Navier-Stokes equations with variable thermodynamic and transport properties. Both finite-rate and local-equilibrium approaches are adopted in the chemical reaction model for dissociation and ionization of the inlet air. In the finite rate approach, eleven species equations coupled with fluid dynamic equations are solved simultaneously. In the local-equilibrium approach, instead of solving species equations, an efficient chemical equilibrium package has been developed and incorporated into the flow code to obtain chemical compositions directly. Gas properties for the reaction products species are calculated by methods of statistical mechanics and fit to a polynomial form for C(p). In the present study, since the chemical reaction time is comparable to the flow residence time, the local-equilibrium model underpredicts the temperature in the shock layer. Significant differences of predicted chemical compositions in shock layer between finite rate and local-equilibrium approaches have been observed.
2',5'-linked DNA is a template for polymerase-directed DNA synthesis.

Genomes are composed of nucleic acids bearing 3‘,5‘-phosphodiester-linked sugars. The 2‘,5‘-phosphodiester linkage is a fundamental alternative to the natural linkage and is the predominant product of most nontemplate, nonenzymatic oligomerizations of nucleotide monomers. This fact suggests a chemical bias for the formation of 2‘,5‘-phosphodiester bonds, an important consideration in the context of molecular evolution on Earth or elsewhere. Although 2‘,5‘-linked RNA occurs naturally, it is evidently not used to encode genetic information. Nevertheless, the capacity of the 2‘,5‘-phosphodiester linkage to serve as a genetic material has been probed in laboratory experiments. Initial studies examined both self-pairing and pairing with natural nucleic acids. These studies showed that, while 2‘,5‘-linked DNA and RNA form double and triple helices with themselves, their interactions with natural nucleic acids are asymmetricpairing is seen with 3‘,5‘-linked RNA but not DNA. Although the ability to form a stable ...
Priming by natural category membership in the left and right cerebral hemispheres.

Abstract The cerebral representation of category information was examined in a single word priming paradigm, during which the N400 component of the event-related potential (ERP) was recorded. The visual half-field paradigm was employed in order to selectively stimulate the two hemispheres. To investigate which aspects of category membership are relevant in producing priming, two types of related stimuli were presented. In one condition pairs of exemplars had a higher amount of feature overlap (e.g., MOSQUITO-FLEA) than in the other (e.g., SOFA–VASE). Significant priming was obtained only for stimuli in the high feature overlap condition and then only when these were presented to the left visual field (LVF)/right hemisphere (RH). This finding was interpreted within our recent model of semantic memory wherein the right hemisphere represents items on the basis of distributed individual features, whereas the left hemisphere (LH) represents semantic information locally, within a spreading activation system, where priming occurs exclusively through associative links. It was concluded that knowledge regarding category membership is maintained in the RH, on the basis of feature coding.
Spectral hole burning in the dielectronic recombination from a continuum of finite bandwidth

The presence of an electric field converts the intermediate autoionizing Rydberg nl states, through which dielectronic recombination passes, into nk Stark states, which have autoionization and capture rates in excess of the radiative decay rates and contribute to dielectronic recombination. In zero field the high l states do not contribute to dielectronic recombination, but the conversion to Stark states makes it possible and raises the dielectronic recombination rate. However, an electric field can also result in coupling to loss channels which locally reduce the dielectronic recombination rate. We have observed holes in the spectrum of dielectronic recombination from the Ba 6p{sub 3{approx}}{sub sol{approx}}{sub 2}8g continuum of finite bandwidth via the intermediate 6p{sub 1{approx}}{sub sol{approx}}{sub 2}ng states. The holes appear when an electric field is applied, and we attribute them to interaction with rapidly decaying 6p{sub 3{approx}}{sub sol{approx}}{sub 2}8l states, which diverts flux from dielectronic recombination.
Ethmoidal dural arteriovenous fistulae: an assessment of surgical and endovascular management.

Objective Endovascular treatment of ethmoidal dural arteriovenous fistulae (DAVFs) has become technically feasible, but its relative risks and benefits have not justified its use. We present a series of patients with ethmoidal DAVFs treated almost exclusively with surgery at an institution where expert endovascular therapy was available. Surgical risks, treatment efficacy, and patient outcomes were determined for comparison with published endovascular data. Methods Sixteen patients with ethmoidal DAVFs were treated during a 17-year period from 1982 to 1999. In three patients, feeding arteries from the internal maxillary artery were embolized; no ophthalmic artery embolizations were performed. A low bifrontal surgical approach was used in most patients to expose, coagulate, and divide the fistulous site. Results Ethmoidal DAVFs were occluded grossly and angiographically in all 16 patients. There was no treatment-associated neurological morbidity, and clinical outcomes were good in all but one patient who was comatose initially. Conclusion Review of our surgical experience with ethmoidal DAVFs as well as published endovascular results for these lesions suggests that endovascular management of ethmoidal DAVFs has a small but clinically significant risk to vision, is rarely effective in curing the fistula, and does not eliminate the need for surgery. In contrast, surgical management has no associated risk to vision, is highly effective at obliterating the fistula, and can contribute to good clinical outcomes in most patients. For these reasons, surgical management of ethmoidal DAVFs remains the treatment of choice.
Transition from In Situ to Invasive Testicular Germ Cell Neoplasia is Associated with the Loss of p21 and Gain of mdm-2 Expression

Introduction: The tumor suppressor gene p53 has been shown to transcriptionally regulate expression of the cell cycle dependent kinase inhibitor p21. p53 is in turn regulated by the ubiquitin ligase mouse double minute-2 (mdm-2). We have set out to examine p21 expression in testicular germ cell tumors and its relationship with p53 and mdm-2 expression. Methods: Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded tissue for p53, p21, and mdm-2 in 31 testicular germ cell tumors, which included 17 pure seminomas and 14 mixed germ cell tumors composed predominantly of embryonal carcinoma. Twenty-seven cases contained adjacent areas of intratubular germ cell neoplasia (ITGCN). Results: 17 out of 17 seminomas and 14 out of 14 embryonal carcinomas expressed p53 in both ITGCN and the invasive tumor. In contrast, none of the 17 seminomas and only 2 of 14 embryonal carcinomas revealed positive staining for p21 protein. p21 expression was noted in 18 of 27 cases (67%) of ITGCN, and in 16 of these cases (89%) the corresponding invasive tumor had lost p21 expression. In nine additional cases p21 expression was absent in both the invasive and intratubular tumor. mdm-2 expression was present in 8 out of 17 (47%) seminomas and 13 out of 14 (93%) embryonal carcinomas but was present in only 2 out of 27 (7%) cases of ITGCN. Statistically significant associations for loss of p21 and gain of mdm-2 expression in invasive tumors were present (P < .0001). Conclusions: The co-expression of p53 and p21 in ITGCN is consistent with preservation of p53-directed induction of p21. The loss of p21 expression in invasive tumors suggests a disruption of the p53 regulatory pathway. The inverse correlation of p21 and mdm-2 expression in both ITGCN and invasive tumors could indicate that loss of the functional p53 regulatory pathway may be correlated with the onset of mdm-2 expression. These results raise the possibility that the loss of p21 expression may be associated with the development of invasive germ cell tumors from ITGCN. Persistent p53 expression in the presence of mdm-2 suggests that in testicular germ cell tumors, while mdm-2 can block the transactivation potential of p53, it can no longer target p53 for degradation.
The Analysis of Metals at a Distance Using Laser-Induced Breakdown Spectroscopy

Laser-Induced Breakdown Spectroscopy (LIBS) has been used to provide a rapid analysis of metals at distances between 0.5 and 2.4 m from the focusing lens and light-collection optics. The laser sparks were generated with the use of pulses from a Nd:YAG laser, and the spark light was collected by the use of a fiber optic cable. The wide acceptance angle of the cable relaxed the constraint that the spark be formed at a precise location for maximum light-collection efficiency and allowed the detection system to be placed remote from the sample. The identification of the main elemental component of eight metals using lines over a 40-nm spectral region was demonstrated by the use of a single laser pulse to record each spectrum. The accuracy and precision of analysis of the minor constituents of steel were determined, and the effect of surface contamination was examined. The application of LIBS to some industrial monitoring situations is discussed.
Cataract-Linked γD-Crystallin Mutants Have Weak Affinity to Lens Chaperones α-Crystallins

To test the hypothesis that α-crystallin chaperone activity plays a central role in maintenance of lens transparency, we investigated its interactions with γ-crystallin mutants that cause congenital cataract in mouse models. Although the two substitutions, I4F and V76D, stabilize a partially unfolded γD-crystallin intermediate, their affinities to α-crystallin are marginal even at relatively high concentrations. Detectable binding required further reduction of γD-crystallin stability which was achieved by combining the two mutations. Our results demonstrate that mutants and possibly age-damaged γ-crystallin can escape quality control by lens chaperones rationalizing the observation that they nucleate protein aggregation and lead to cataract.
Numerical analysis of black hole evaporation

Black hole formation and/or evaporation in two-dimensional dilaton gravity can be described, in the limit where the number [ital N] of matter fields becomes large, by a set of second-order partial differential equations. In this paper we solve these equations numerically. It is shown that, contrary to some previous suggestions, black holes evaporate completely a finite time after formation. A boundary condition is required to evolve the system beyond the naked singularity at the evaporation end point. It is argued that this may be naturally chosen so as to restore the system to the vacuum. The analysis also applies to the low-energy scattering of [ital S]-wave fermions by four-dimensional extremal, magnetic, dilatonic black holes.
What Every Graduating Medical Student Should Know About Urology: The Stakeholder Viewpoint

OBJECTIVES What should every medical student know about urology upon graduating from medical school? To answer this question, we conducted a survey of key stakeholders in an effective medical student education in urology. METHODS Directors of the generalist residencies in the United States (emergency medicine, family medicine, internal medicine, and pediatrics), directors of urology residencies, medical student educators in urology, and applicants to the 2006 urology residency match were invited to complete an online survey. Participants were asked to select the 5 most important topics to be included in a core urology curriculum for all medical students. RESULTS Among 1859 stakeholders surveyed, response rates by stakeholder cohort ranged from 67% to 26% (overall 44%). There was marked homogeneity among participant groups as to what respondents considered to be the most important topics for a core urology curriculum for medical students. Based on aggregate data, the 8 most commonly cited topics included urinary stone disease (75% of respondents), hematuria (65%), urinary tract infections in adults (53%), benign prostatic hyperplasia (52%), urinary incontinence (45%), prostate cancer (45%), screening with prostate-specific antigen (33%), and testis torsion (24%). CONCLUSIONS This survey has identified the most important urology topics about which medical students should learn before graduation. Work is currently under way under the aegis of the American Urological Association to develop materials to standardize student education in these core topics across the United States.
BULK FLOW REDUX

As so often happens in science, yesterday's conflicts become today's consensus. There is truth in both the bulk flow and receptor-mediated models of ER export. Receptor-mediated export is particularly appropriate for minor proteins, and the challenge here is to identify the receptors. Bulk flow is appropriate for abundant proteins, too many to permit receptor-mediated sorting. Here the challenge is to understand the features that permit exclusion from COPI-coated vesicles. It may well be that these are not the discrete signals that we are used to dealing with but more colligative properties of proteins that permit specific self-association.
Magnesium protoporphyrin monoester destruction by extracts of etiolated red kidney bean leaves

Abstract Cell-free extracts prepared from the leaves of etiolated red kidney bean (Phaseolus vulgaris) seedlings contain an enzyme which degrades Mg protoporphyrin monoester (Mg Proto ester). The activity is O2-dependent, heat- labile, and has a pH optimum at 7.5. The enzyme has been partially purified by gel filtration on Sephadex G-25. It is suggested that this enzyme may play a role in porphyrin turnover.
Communal and Exchange Approaches To Sexual Relations

Sexual relationships may be viewed from a communal perspective which emphasizes caring and concern for a partner's sexual needs and preferences, or else from an exchange perspective which emphasizes a quid pro quo approach. The purpose of the present investigation was to construct and validate an objective self-report instrument measuring communal and exchange approaches to sexual relations, the Sexual Relationship Scale (SRS). Reliability analyses indicated that the two SRS scales designed to measure communal and exchange approaches to sexual relations had reasonably strong internal consistency, and other analyses revealed that, among females, the two SRS subscales were essentially orthogonal to one another. In addition, it was found that the Sexual Relationship Scale correlated in predictable ways with measures of relationship orientation. Additional evidence indicated that men's and women's relationship satisfaction was influenced by their tendency to approach sexual relationships from either a communal or an exchange perspective.
On the interpretation of geopotential height tendency equations

Abstract The conceptual model for height tendency presented by Hirschberg and Fritsch directly links upper-level virtual temperature tendency with low-level height tendency, overlooking the essential dynamics of mass divergence. An analysis of the complete height tendency equation shows that upper-level virtual temperature change car only indirectly induce low-level height change by driving ageostrophic circulations. To avoid misconceptions about middle- and lower-tropospheric height tendency, the dynamics of height tendency are reviewed.
Hypericum perforatum (St John's Wort) for Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: A Randomized Controlled Trial

Context Stimulant medication can effectively treat 60% to 70% of youth with attention-deficit/hyperactivity disorder (ADHD). Yet many parents seek alternative therapies, and Hypericum perforatum (St John's wort) is 1 of the top 3 botanicals used. Objective To determine the efficacy and safety of H perforatum for the treatment of ADHD in children. Design, Setting, and Participants Randomized, double-blind, placebo-controlled trial conducted between March 2005 and August 2006 at Bastyr University, Kenmore, Washington, among a volunteer sample of 54 children aged 6 to 17 years who met Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria for ADHD by structured interview. Intervention After a placebo run-in phase of 1 week, participants were randomly assigned to receive 300 mg of H perforatum standardized to 0.3% hypericin (n = 27) or a matched placebo (n = 27) 3 times daily for 8 weeks. Other medications for ADHD were not allowed during the trial. Main Outcome Measures Performance on the ADHD Rating Scale–IV (range, 0-54) and Clinical Global Impression Improvement Scale (range, 0-7), and adverse events. Results One patient in the placebo group withdrew because of an adverse event. No significant difference was found in the change in ADHD Rating Scale–IV scores from baseline to week 8 between the treatment and placebo groups: inattentiveness improved 2.6 points (95% confidence interval [CI], −4.6 to −0.6 points) with H perforatum vs 3.2 points (95% CI, −5.7 to −0.8 points) with placebo (P = .68) and hyperactivity improved 1.8 points (95% CI, −3.7 to 0.1 points) with H perforatum vs 2.0 points (95% CI, −4.1 to 0.1 points) with placebo (P = .89). There was also no significant difference between the 2 groups in the percentage of participants who met criteria for improvement (score ≤2) on the Clinical Global Impression Improvement Scale (H perforatum, 44.4%; 95% CI, 25.5%-64.7% vs placebo, 51.9%; 95% CI, 31.9%-71.3%; P = .59). No difference between groups was found in the number of participants who experienced adverse effects during the study period (H perforatum, 40.7%; 95% CI, 22.4%-61.2% vs placebo, 44.4%; 95% CI, 25.5%-64.7%; P = .78). Conclusion In this study, use of H perforatum for treatment of ADHD over the course of 8 weeks did not improve symptoms. Trial Registration clinicaltrials.gov Identifier: NCT00100295
Clinicopathologic findings from lacrimal sac biopsy specimens obtained during dacryocystorhinostomy.

PurposeTo retrospectively review the pathologic diagnoses and clinical characteristics of patients undergoing dacryocystorhinostomy (DCR).MethodsSpecimens accessioned between 1991 and 2001 in a single ophthalmic pathology laboratory were reviewed. All of the specimens included a lacrimal sac biopsy
Low perceived social support and post-myocardial infarction prognosis in the enhancing recovery in coronary heart disease clinical trial: the effects of treatment.

Objective In post hoc analyses, to examine in low perceived social support (LPSS) patients enrolled in the Enhancing Recovery in Coronary Heart Disease (ENRICHD) clinical trial (n = 1503), the pattern of social support following myocardial infarction (MI), the impact of psychosocial intervention on perceived support, the relationship of perceived support at the time of MI to subsequent death and recurrent MI, and the relationship of change in perceived support 6 months after MI to subsequent mortality. Methods Partner status (partner, no partner) and score ( 12 = moderate support) on the ENRICHD Social Support Instrument (ESSI) were used post hoc to define four levels of risk. The resulting 4 LPSS risk groups were compared on baseline characteristics, changes in social support, and medical outcomes to a group of concurrently enrolled acute myocardial infarction patients without depression or LPSS (MI comparison group, n = 408). Effects of treatment assignment on LPSS and death/recurrent MI were also examined. Results All 4 LPSS risk groups demonstrated improvement in perceived support, regardless of treatment assignment, with a significant treatment effect only seen in the LPSS risk group with no partner and moderate support at baseline. During an average 29-month follow-up, the combined end point of death/nonfatal MI was 10% in the MI comparison group and 23% in the ENRICHD LPSS patients; LPSS conferred a greater risk in unadjusted and adjusted models (HR = 1.74-2.39). Change in ESSI score and/or improvement in perceived social support were not found to predict subsequent mortality. Conclusions Baseline LPSS predicted death/recurrent MI in the ENRICHD cohort, independent of treatment assignment. Intervention effects indicated a partner surrogacy role for the interventionist and the need for a moderate level of support at baseline for the intervention to be effective.
Changes in proteins and peroxidases induced by compatible pollination in the ovary of Nicotiana tabacum L. ahead of the advancing pollen tubes

Proteins and peroxidases produced by the ovules and placenta of tobacco (Nicotiana tabacum L.) in response to compatible pollination were analyzed by two-dimensional polyacrylamide gel electrophoresis and by enzyme staining in flat-bed native isoelectric focusing gels. For two-dimensional gels, ovaries were sampled at 36 h after pollination, at which time pollen tubes have penetrated much of the length of the style but have not yet entered the ovary. At least 11 major proteins from pollinated ovaries had no detectable counterparts in unpollinated ovaries. These showed a range of molecular mass and pI. For peroxidase isozyme assays, ovaries were sampled at 0, 12, 24, 36 and 48 h after pollination. At 45–50 h, pollen tubes were beginning to enter the top of the ovary but could still be separated from the ovules and placenta during sampling. Ovules and placentae from unpollinated pistils showed only one form of peroxidase, whereas those from pollinated pistils showed additional isozymes at pH 5.4 and pH 10.0. Both new isozymes increased in staining intensity over the first 36 h after pollination. At 48 h, however, the acidic peroxidase had continued to increase, while the basic component had declined so as to be barely detectable. The observations are discussed in relation to accumulating evidence that some form of pollination-induced signal reaches the ovary ahead of the advancing pollen tubes. The nature of this signal and possible involvement of peroxidases are also briefly discussed.
Non-contact measurement of oil tube thread and the application

The paper presents a detecting method for oil tube thread, which combines optical techniques and image processing techniques to measure the physical dimension of tube thread and give further analysis. The relevant technqiues such as projection of tube thread, feature of thread image and image processing are discussed, the way for thread image measuring and calibration is introduced in detail. The measurement accuracy is also considered. Finally the application of the measurement is illustrated.
Cerium under the lens

Eric J. Schelter ponders on cerium's rather puzzling redox reactivity, and the varied practical applications that have emerged from it.
Visiting Knowledge in Anthropology: An Introduction

It is symptomatic of my dilemma in introducing this special issue of Ethnos that the title of this project went through a half-dozen different iterations before settling at ‘Revisiting the Anthropo...
Equilibrium sedimentation in density gradients of DNA preparations from animal tissues.

Experiments on the equilibrium sedimentation in CsCl density gradients of the DNA from adult mouse tissues, three tumors, mouse tissue culture cells, and from three different tissues of the monkey, the guinea-pig, and the alligator are described. The DNA banding patterns were characteristic for each species. Bimodal distributions were observed for mouse and guinea-pig DNA. The mean buoyant densities of the principal and the satellite mouse DNA bands were 1·701 and 1·690 g cm −3 , respectively. The mean buoyant density of the major guinea-pig DNA band was 1·697 g cm −3 , and that of the minor band was 1·703 g cm −3 . A single band was found in the case of monkey or alligator DNA but these differed in mean buoyant density and in band variance. The mean buoyant densities and the band variance were the same for the differentiated tissues of a given animal species.
The Fallacy of Begging the Question

Begging the question — roughly, positing in the premises what is to be proved in the conclusion — is a perplexing fallacy.1 Are not question-begging arguments valid? Yes, we may find ourselves saying, but they are fallacious despite their validity, owing to their inability to establish the truth of a conclusion which is not already known. But are not question-begging arguments sometimes effective in bringing an audience to an awareness of the truth of the conclusion ? How can a dialectical maneuver which is capable of effecting epistemic progress be a fallacy, an illegitimate maneuver? In such cases of success, we can reply, the audience was simply in need of some logical coaching — a question-begging argument is of its very nature ill-suited for producing new knowledge in someone who is being fully rational. But then are not all valid arguments question-begging, since the conclusions are at least implicitly contained in the premises in such a way that a fully rational individual can never augment his knowledge through such arguments? No, we may answer, only those valid arguments in which the proposition constituting the conclusion appears, whether distinguised or not, as a distinct premise are question-begging; if several premises go together to imply a conclusion, the argument does not beg the question, But why is it legitimate to posit premises which more-or-less implicitly contain the conclusion, while it is illegitimate to posit premises which more-or-less explicitly contain the conclusion ? Because, we are tempted to say, a question-begging argument is one in which what is to be proved in the conclusion is posited in the premises, and this positing must be more-or-less explicit in order for a fallacy to be committed!
X-ray study and electrical properties of system BaxSr(1−x)MoO3

Abstract The two molybdates (IV) BaMoO 3 and SrMoO 3 form an unlimited series of solid solutions of the type Ba x Sr (1− x ) MoO 3 . Thermal e.m.f. and resistivity measurements on several compounds of this system were performed. The pure compounds BaMoO 3 and SrMoO 3 were found to have a perovskite structure between room temperature and 1000°C. The cell constants vary linearly with temperature.
Robotic preparation of Sodium Acetate C 11 Injection for use in clinical PET

Abstract Sodium Acetate C 11 Injection is a radiopharmaceutical commonly used for clinical studies with positron emission tomography (PET). We have designed a fully-automated robotic system for the compounding of this 20-minute half-lived tracer in the clinical setting. The system is comprised of five modular workstations that are configured in a flexible manner to accommodate all of the steps in the production of the labeled drug. The Trapping Station isolates cyclotron-produced [ 11 C]CO 2 gas from the target and directs carbonation of methylmagnesium Grignard in diethyl ether. The Heating Station hydrolyzes the intermediate, and removes ether and unreacted [ 11 C]CO 2 from the mixture. The Extraction Station removes ionic and organic contaminants from the drug using solid-phase extraction (AG 11A8 and C18 resin). The Filtration Station sterilizes the radiopharmaceutical, and tests membrane patency post filtration. The Assay Station measures the weight and radioactivity content of the Final Product Container, facilitating calculation of activity concentration in a remote manner. Rapid quality control methodology has also been developed that is suitable for pre-release analysis of the drug product. For a 7.5 min irradiation with a 40 μA proton beam, 223–300 mCi of Acetate C 11 Injection with purity meeting USP standards is produced within 23 min. This robotic system is a reliable method for producing Sodium Acetate C 11 Injection, USP in the clinical setting with minimal personnel exposure. Moreover, its design flexibility permits synthesis of additional 11 C- or 18 F-labeled PET tracers within the same shielded hot cell.
Saturn's Temperature Field from High-Resolution Middle-Infrared Imaging

Saturn was imaged between 8 and 24.5 micrometers at ∼3000-kilometer resolution with the Keck I Telescope. Saturn's atmosphere has zonal temperature bands, which are mostly uncorrelated with visible cloud reflectivity, strong 100-millibar zonal temperature oscillations near 32°S, a warm south polar cap, and a compact hot point within 3° of the south pole.
Apoptosis and cell proliferation in proliferative retinal disorders: PCNA, Ki-67, caspase-3, and PARP expression.

Purpose: To assess the incidence of cell proliferation and apoptosis in epiretinal membranes from eyes with proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR), and macular pucker (MP) and to further investigate the potential involvement of key executors of apoptosis. Methods: Epiretinal membranes were obtained from the eyes of 23 patients who underwent vitrectomy surgery for recurrent retinal detachment due to PVR (n = 16), traction retinal detachment due to PDR (n = 5), and macular pucker (n = 2). Cell proliferation was evaluated by Ki-67 and PCNA (proliferation cell nuclear antigen) immunostaining. Apoptosis was assessed by TUNEL (terminal deoxynucleotidyl transfrase-dUTP-nick end labeling). The expression of caspase-3 and PARP (poly-ADP-ribose-polymerase) was detected using antibodies against activated caspase-3 and p85 fragment of PARP. Cytokeratin and activated caspase-3/PARP, GFAP (glial fibrillary acidic protein) and activated caspase-3/PARP double staining were used to...
A multilevel model of the impact of farm-level best management practices on phosphorus runoff.

: Multilevel or hierarchical models have been applied for a number of years in the social sciences but only relatively recently in the environmental sciences. These models can be developed in either a frequentist or Bayesian context and have similarities to other methods such as empirical Bayes analysis and random coefficients regression. In essence, multilevel models take advantage of the hierarchical structure that exists in many multivariate datasets; for example, water quality measurements may be taken from individual lakes, lakes are located in various climatic zones, lakes may be natural or man-made, and so on. The groups, or levels, may effectively yield different responses or behaviors (e.g., nutrient load response in lakes) that often make retaining group membership more effective when developing a predictive model than when working with either all of the data together or working separately with the individuals. Here, we develop a multilevel model of the impact of farm level best management practices (BMPs) on phosphorus runoff. The result of this research is a model with parameters which vary with key practice categories and thus may be used to evaluate the effectiveness of these practices on phosphorus runoff. For example, it was found that the effect of fertilizer application rate on farm-scale phosphorus loss is a function of the application method, the hydrologic soil group, and the land use (crop type). Further, results indicate that the most effective method for controlling fertilizer loss is through soil injection. In summary, the resultant multilevel model can be used to estimate phosphorus loss from farms and hence serve as a useful tool for BMP selection.
Differential heparin inhibition of skeletal muscle alpha-dystroglycan binding to laminins.

The laminin binding properties of α-dystroglycan purified from rabbit skeletal muscle membranes were examined. In a solid phase microtiter assay, 125I-laminin (laminin-1) bound to purified α-dystroglycan in a specific and saturable manner with a half-maximal concentration of 8 nM. The binding of 125I-α-dystroglycan to native laminin and merosin (a mixture of laminin-2 and −4) was also compared using the solid phase assay. The absolute binding of 125I-α-dystroglycan to laminin (6955 ± 250 cpm/well) was similar to that measured for merosin (7440 ± 970 cpm/well). However, inclusion of 1 mg/ml heparin in the incubation medium inhibited 125I-α-dystroglycan binding to laminin by 84 ± 4.3% but inhibited 125I-α-dystroglycan binding to merosin by only 17 ± 5.2%. Similar results were obtained with heparan sulfate, while de-N-sulfated heparin, hyaluronic acid, and chondroitin sulfate had no differential effect. These results were confirmed by iodinated laminin and merosin overlay of electrophoretically separated and blotted dystrophin-glycoprotein complex. In contrast to the results obtained with skeletal muscle α-dystroglycan, both laminin and merosin binding to purified brain α-dystroglycan was significantly inhibited by heparin. Our data support the possibility that one or more heparan sulfate proteoglycans may specifically modulate the interaction of α-dystroglycan with different extracellular matrix proteins in skeletal muscle.
Phase-slip mechanism in ultrasmall Josephson junctions with fluctuating coupling

Abstract The rate of the phase-slip in an overdamped Josephson junction in the presence of both the thermal quasiparticle noise and the critical current fluctuations is calculated. Dramatic increase of the standard Kramers rate is predicted for large intensity of the critical current noise. For a temperature-independent noise intensity, produced by quantum ionic tunneling processes in the junction barrier, significant departures from the Arrhenius law take place in the T -dependence of the rates below a characteristics temperature which may exceed the temperature for the crossover from the thermal activation to the macroscopic quantum tunneling.
PtSiO2: III. Activity and selectivity for some hydrogenation reactions

Abstract The activities and selectivities of the series of Pt SiO 2 catalysts described in Parts I [Uchijima, T., Hermann, J. M., Inoue, Y., Burwell, R. L., Jr., Butt, J. B., and Cohen, J. B., J. Catal. 50, 111 (1977)] and II [Sashital, S., Cohen, J. B., Burwell, R. L., Jr., and Butt, J. B., J. Catal. 50, 111 (1977)] have been determined for the hydrogenation of cyclopropane, methylcyclopropane, and propene. All three reactions are found to be mildly structure sensitive under the conditions of investigation, with variations in the turnover numbers by a factor of about; 3 over the range of metal exposure. Activation energies were essentially the same for the three reactions and in all cases were independent of the percentage of Pt exposed. On this basis, a simple geometric correlation is shown to provide a reasonable explanation of the data, except where significant strain exists within the metal crystallites. It is also shown that an excellent correlation of activity vs metal vibrational amplitude is obtained for these catalysts.
Short form of α9 promotes α9β1 integrin-dependent cell adhesion by modulating the function of the full-length α9 subunit

The α9β1 integrin is a multifunctional receptor that interacts with a variety of ligands including vascular cell adhesion molecule 1, tenascin-C, and osteopontin. A 2.3-kb truncated form of α9 integrin subunit cDNA was identified by searching the Medline database. This splice variant, which we called the short form of α9 integrin (SFα9), encodes a 632-aa isoform lacking transmembrane and cytoplasmic domains, and its authentic expression was verified by PCR and Western blotting. SFα9 is expressed on the cell surface but cannot bind ligand in the absence of the full-length α9 subunit. Over-expression of SFα9 in cells expressing full-length α9 promotes α9-dependent cell adhesion. This promoting effect of SFα9 requires the authentic cytoplasmic domain of the co-expressed full-length α9 subunit. Thus, SFα9 is a novel functional modulator of α9β1 integrin by inside-out signaling.
On the boundary conditions for envelope-function approaches for heterostructures

Abstract It is shown that integration of the set of differential equations that describes semiconductor heterostructures within the envelope-function approach gives the proper boundary conditions for the envelope functions at abrupt interfaces. These boundary conditions are correct in the sense that they ensure the continuity of the (cell-averages of the) particle density and the probability current density. Proper symmetrization rules for the effective Hamiltonian can be inferred from the requirement to conserve the probability current density.
RTNS-II: Present Status

The present status of the RTNS-II facility is described and typical operating parameters are given. A brief discussion is given of the methods used in production of the TiT2 targets as well as their performance and tritium handling at RTNS-II. The various types of non-interactive beam diagnostics presently in use at the neutron sources are outlined. The on-line computer system which provides a time history of an irradiation and records target performance is described. Examples are listed of several representative experimental programs which have been carried out thus far at RTNS-II. These include both active and passive experiments. Finally, several of the major improvements to the facility made since the beginning of the experimental program are given.
Staying the Course in Times of Change Preparing Teachers for Language Minority Education

This article describes how passage of Proposition 227 (P-227), the popular California initiative restricting bilingual education, has influenced teacher preparation to authorize specialized instruc...
A fully-automated analyzer for determining haloacetic acid concentrations in drinking water.

Abstract A fully-automated, on-line, real-time analyzer has been developed for preconcentration and analysis of haloacetic acids (HAAs). Preconcentration of HAAs is achieved by sample acidification and solid phase extraction onto a hydrophobic polymeric resin using sequential injection analysis (SIA). The HAAs preconcentrate is then analyzed using post-column reaction-ion chromatography (PCR-IC), which is selective for HAAs. Systematic optimization of SIA preconcentration parameters are described followed by detailed method detection limit (MDL), accuracy, precision, and linearity studies. MDL values for the individual HAA9 species range from 0.4 to 0.9 μg L−1. Side-by-side comparison studies of HAAs analysis in 14 real-world drinking water samples from Alabama, Arkansas, Kentucky, Minnesota, Missouri, Mississippi, New York, Pennsylvania and Tennessee are presented that compare the optimized SIA-PCR-IC to USEPA Method 552.3. Trace levels of HAAs detected in select samples are reported, and the bias values calculated between the two methods are typically less than 5 μg L−1 for eight of the nine individual HAAs.
EFFECT OF TRUCK OPERATING WEIGHT ON HEAVY-DUTY DIESEL EMISSIONS

Heavy-duty diesel vehicles are substantial contributors of oxides of nitrogen (NOx) and particulate matter (PM) while carbon monoxide and hydrocarbon (HC) emissions from diesel vehicles receive less attention. Truck emissions inventories have traditionally employed average fuel economy and engine efficiency factors to translate certification into distance-specific (g/mi) data, so that inventories do not take into account the real effects of truck operating weight on emissions. The objective of this research was to examine weight corrections for class 7 and 8 vehicles (over 26 000 lb (11 793 kg) gross vehicle weight) from a theoretical point of view and to present a collection of original data on the topic. It was found by combining an empirical equation with theoretical truck loads that the NOx emissions increased by ∼54% for a doubling of test weight. Emissions data were gathered from specific tests performed using different test weights and using various test schedules, which can consist of cycles or ro...
Directed Electrodeposition of Polymer Films Using Spatially Controllable Electric Field Gradients

We report a method for the directed electrodeposition of polymer films in various patterns using spatially controllable electric field gradients. One- and two- dimensional surface electric field gradients were produced by applying different potential values at spatially distinct locations on an electrode surface. Variations in the resulting local electrochemical potentials were used to spatially manipulate the rate of electrodeposition of several polymers. By controlling the electric field gradient in the presence of sequentially varying deposition solutions, complex polymer patterns could be produced. One-dimensional structures consisting of alternating bands of polyaniline and either poly(phenylene) oxide or poly(aminophenylene) oxide were produced, as well as more complex two-dimensional structures. Film characterization was achieved through optical imaging, UV−vis spectroscopy, and ellipsometry. Results indicate that this directed deposition technique is a simple strategy to create complex, millimeter...
Chemotaxonomy of Subulitermes and Nasutitermes termine soldier defense secretions. Evidence against the hypothesis of diphyletic evolution of the Nasutitermitinae

The soldier defense secretions of advanced neotropical termites of the genus Subulitermes (Isoptera, Nasutitermitinae) contain diterpenes identicalto those found in Nasutitermes species, while soldiers of the primitive mandibulate nasute genera Cornitermes, Armitermes and Rhynchotermes lack diterpenoid compounds. It now appears improbable that the elongate nasus and intimately associated terpenoid defense secretions evolved from a primitive mandibulate ancestor independently along two phyletic branches. An alternate hypothesis is proposed in which morphological divergence from a common diterpene-producing ancestor may have occurred.