cssi/SciSciGPT-SciSciNet huggingface dataset:
HRTEM study comparing naturally and experimentally weathered pyroxenoids

The mineralogy and chemistry of both naturally and experimentally weathered MnSiO3 chain silicate minerals (rhodonite and pyroxmangite) were compared. In natural MnSiO3, high-resolution transmission-electron microscope observations reveal that alteration begins at grain boundaries and planar defects parallel to the silicate chains that represent junctions between regions with different chain periodicities. Dissolution along these defects results in elongate etch pits that may be partly filled by smectite. Smectite (Ca0.3Mn2.2Zn0.4Al0.1Si4O10(OH)2) also develops in larger etches at grain boundaries. The Zn apparently released by weathering of coexisting sphalerite, may facilitate crystallization of manganesesmectite; rhodochrosite is also an initial product. X-ray diffraction patterns from highly altered materials reveal only rhodochrosite and quartz. Simplified reactions are H2CO3(aq)+4MnSiO3(s)=Mn3Si4O10(OH)2(s)+MnCO3(s) accompanied by 3H2CO3(aq)+Mn3Si4O10(OH)2(s)=3MnCO3(s)+4SiO2(s)+4H2O(1) Pyroxenoid dissolution is incongruent under experimental conditions. A 3–7 nm-thic layer of amorphous silica is present at the mineral surface after ∼ 2000 h of reaction in acidic and near-neutral pH solutions that were undersaturated with respect to bulk amorphous silica. This thin layer of polymeric silica, which is absent on unreacted grains, is interpreted to have formed largely by incongruent dissolution at the mineral surface as protons in solution rapidly exchange for near-surface Mn. The layer may also contain silica readsorbed back onto the surface from solution. The net result is that silica from the pyroxenoid is redistributed directly into reaction products. Upon aging in air for a year, leached layers partially recrystallize. Both natural and experimental reactions produce secondary products by direct modification of the pyroxenoid surface. Manganese does not change oxidation state in the early stages of weathering in either setting. Unlike orthosilicates, compositional variations exert only a secondary control on chain silicate dissolution rates. For all chain silicate minerals, depolymerization of the silicate anion probably limits overall dissolution rates. As the thickness of the modified layer increases, rates may be further suppressed by diffusion (through the leached surface in the case of experimental reactions, and through secondary minerals in the case of natural weathering). The rates for wollastonite are exceptional in that the mineral dissolves more rapidly than other chain silicates and because leaching reactions are more pronounced. Natural surface modification reactions appear to be distinctive in that they occur in the presence of higher concentrations of metal cations. Clay mineral formation may be promoted by periodic drying.
Role of ascorbic acid in procollagen expression and secretion by human intestinal smooth muscle cells.

The role of ascorbate in the production and secretion of procollagen by human intestinal smooth muscle cells and the conditions in culture for optimal ascorbate bioefficacy were studied. Procollagen synthesis and secretion were determined by the incubation of cells with L-[5-3H]proline, and the quantitation of radiolabelled procollagen bands in the cell layer and the culture medium by polycrylamide slab gel electrophoresis and densitometry. When cells were cultured without ascorbate in the culture medium, procollagen secretion into the medium was 75% less than in cells receiving fresh ascorbate daily. In the cell layer, in contrast, procollagen accumulation was fourfold greater in the scorbutic cells than in the ascorbate-replete cells. These findings contrasted with those in a control line of scorbutic human dermal fibroblasts in which a 95% decrease in procollagen secretion was not associated with any procollagen accumulation in the cells. In the intestinal smooth muscle cells, the absence of ascorbate resulted in a 25 and 50% decrease in steady-state levels of procollagen I and III mRNA, respectively, compared to a 40 and 75% decrease in fibroblasts. Heat inactivation of the serum in the culture medium augmented the promotion of procollagen secretion by ascorbate two- to fourfold. L-ascorbate phosphate did not increase the activity of L-ascorbate when replaced in medium either daily or every 4 days, and its efficacy was not augmented by serum heat inactivation. The changing of culture medium induced collagen secretion in the absence of ascorbate, but this process was markedly enhanced by ascorbate and induced a transient decrease in the steady-state levels of both procollagen and nonprocollagen mRNAs. The predominant action of L-ascorbate on HISM cells in vitro is to promote procollagen secretion and not procollagen synthesis. L-ascorbate-phosphate is not an adequate substitute for L-ascorbate in this cell line. © 1995 Wiley-Liss, Inc.
Bibliography of comparative and veterinary dermatology, part 16.

The first installment of this continuing feature appeared in the jan.-Feb. 1977 issue (p. 37); part 2, March (p. 143); part 3, April (p. 218); part 4, May (p. 287); part 5, June (p. 401); part 6, July-August (p. 505); part 7, September (p. 601); part 8, October (p. 683); part 9, November (p. 764); part 10, December (p. 844); part 11, Jan.-Feb. 1978 (p. 58); part 12, March (p. 142); part 13, April (p. 228); part 14, May (p. 342); and part 15, June (p. 404).
Self-inactivating retroviral vector-mediated gene transfer induces oncogene activation and immortalization of primary murine bone marrow cells.

Insertional mutagenesis leading to insurgence of leukemia has been shown as a consequence of retroviral (RV)-mediated gene transfer in animal models and in clinical trials of gene therapy for X-linked severe combined immunodeficiency. Aberrant expression of oncogenes neighboring the γ-RV vector insertion site via induction by the enhancer element of the viral long terminal repeats (LTRs) is thought to have played a role in leukemogenesis. Consequently, RV vectors devoid of LTR enhancer elements could prove as safer tools for gene transfer. To test this hypothesis, we evaluated the immortalization ability of two RV vectors: one carrying the full-length Moloney leukemia virus (MLV) LTR and one with the same LTR in which the enhancer element was deleted [MLV self-inactivating (SIN)]. Unexpectedly, transduction with MLV SIN resulted in an only slightly and not significant decreased immortalization frequency of primary bone marrow (BM) cultures (about 37%) compared to transduction with MLV (about 48%). Similar to MLV, immortalization by MLV SIN is likely caused by insertional activation of oncogenes including Evi1, Mds1, Mef2c, and Hoxa7. Our results indicate that the MLV SIN, devoid of the LTR enhancer element, was still able to immortalize BM cells by activating nearby gene expression, indicating the need of an accurate selection of the internal promoter to obtain safer SIN RV vectors.
An Outsider within Perspective to Organizational Communication Explicating the Communicative Practices of Co-Cultural Group Members

Drawing from muted group and standpoint theories, this article advances an outsider within perspective describing the ways that traditionally marginalized group members communicate in mainstream or...
Interferon in the treatment of hairy-cell leukemia

The introduction of alpha interferon in 1984 initiated a new and exciting turnaround in the treatment of hairy-cell leukemia. Until that time splenectomy was the only known effective therapy for this disease. Interferon proved to benefit hairy-cell leukemia patients with active disease, whether or not they had undergone prior splenectomy. However, most interferon-induced responses were partial and were of relatively short duration. Purine analogues such as cladribine and pentostatin have since been found to be more effective than alpha interferon and, therefore, have now replaced interferon as first-line therapy for hairy-cell leukemia. At the present time, interferon has a relatively limited role in the treatment of hairy-cell leukemia and it is reserved for a group of selected patients who have failed nucleoside analogue therapy. In this chapter, we discuss the efficacy of interferon and its response duration, toxicity and possible mechanism of action in patients with hairy-cell leukemia.
Epidemiology, Laboratory Detection, and Therapy of Penicillin-resistant Streptococcal Infections

Streptococci cause a wide range of infections in humans including respiratory tract infections, endocarditis, meningitis, bacteremias, and skin and soft tissue lesions. Mutations in the penicillin binding proteins target sites in these organisms have recently caused resistance to penicillins and cephalosporins. The passage of resistant genetic material from one streptococcal species to another has been recognized as one of the mechanisms by which this resistance has occurred and spread. Such resistance has been a particular problem in Streptococcus pneumoniae and viridans group streptococci with penicillin resistance levels in excess of 25%, now common in both groups of organisms worldwide. Fourth-generation cephalosporins, with their enhanced antibacterial activity against Gram-positive organisms (cefpirome > cefepime) and their increased stability to the beta-lactamases produced by many bacterial species, offer a new option for the treatment of potentially life-threatening infections such as pneumococcal pneumonia and meningitis with or without bacteremia. Clinical trials are currently in place to evaluate the role of these agents in these, and other, indications of Gram-positive infections. Prior studies of cefpirome therapy for infections caused by Streptococcus spp. were successful, and recent expanded in vitro investigations profess a future for expanded use of cefpirome to treat infections produced by several Gram-positive species.
Effects of dietary selenium on lipid peroxidation, mitochondrial function and protein profiles in the heart of the myopathic syrian golden hamster (BIO 14.6)

Male, weanling myopathic Syrian Golden Hamsters (BIO 14.6 strain) were fed a selenium-adequate diet (controls) or this diet supplemented with 1.0 ppm selenium (treated) for 30 days. Se-treated animals exhibited a 50% reduction in lipid peroxidation in heart homogenates relative to controls and a 61% increase in mitochondrial glycerophosphate acyltransferase activity. Gel electrophoresis revealed no alterations in cardiac protein profiles from treated or control animals. These data suggest that the selenium prevents peroxidative injury and maintains mitochondrial function in the absence of alterations in cardiac proteins.
Effects of exogenous GM1 and GD1a on S20Y neuroblastoma cells

The effects of exogenous GM1 and GD1a on S20Y murine neuroblastoma cells were assessed by monitoring morphology, tumorigenicity, mitotic index, and plating efficiency. S20Y cells were seeded at a density equivalent to 5 X 10(4) cells per 35-mm tissue culture dish; 38-42 hr after seeding (preconfluent stage) the cells were treated for 12 hr with 100 micrograms of ganglioside per ml of medium in which the serum content was reduced from 10% to 0.5%. Analysis of the cell lipids indicated that added ganglioside became tightly associated with the membrane during the 12-hr exposure. GM1 treatment resulted in increased projections on the cell surface and fine structures projecting from the cell processes. GD1a treatment resulted in a reduction in the cellular mitotic index. Plating efficiency was reduced by both GM1 and GD1a. Neither ganglioside affected tumorigenicity of the S20Y cells. Twelve hours after removal of the added ganglioside and exposure of the cells to normal medium, the ganglioside composition of the membranes from treated cells approached that of the controls, and the ganglioside-induced effects had been reversed. These results suggest that addition of specific gangliosides induces different cellular responses and that these changes are dependent upon the continued presence of the ganglioside.
Photophysical studies of uranyl complexes. 3. Photodecomposition of the uranyl complexes of ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid

Abstract The photodecomposition of the two title compounds has been carried out at 254 nm, and a single decarboxylation of the ligand was observed in each case. The decarboxylated complexes that resulted were characterized by visible and infrared spectroscopy, and it was concluded that uranium(IV) products were produced as a result of the reaction. The quantum yield of the ethylenediaminetetraacetic acid (EDTA) complex was found to be 0.84 ± 0.02, and the quatum yield of the diethylenetriaminepentaacetic acid (DTPA) was 0.50 + 0.01. The photoproducts could be isolated free from starting material or secondary photoproducts, since these other materials were not water-soluble. When the photoproduct was obtained in solid form, however, it formed as a plastic-like material, and this observation suggested polymerization of the uranium(IV) complexes due to radical reactions that occurred during the photolysis process.
Does alcohol consumption reduce human capital accumulation? Evidence from the College Alcohol Study

It is often conjectured that a significant cost of youthful drinking is the future labour market consequences of having accumulated a lower stock of human capital. While several studies have investigated the effect of youthful drinking on the quantity of human capital stock accumulated, measured by years of education completed or high-school graduation, this paper investigates the effect of alcohol consumption on the quality of human capital stock accumulated as measured by college students GPA. Using data from the Harvard School of Public Health's College Alcohol Study, the indirect effect of the quantity of alcohol consumed on GPA is estimated through hours spent studying as well as the direct effect. Results show that the net total effect of alcohol consumption on GPA is negative for the sample of college students, and that the main effect is via a reduction in the hours spent studying. This finding confirms that high levels of alcohol consumption have an overall negative consequence for academic achie...
Resolution of fibronectin and other uncharacterized proteins by two-dimensional polyacrylamide electrophoresis with thiourea

Abstract Several proteins, which are recognized components of serum, are not resolved by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) under standard conditions. One major example is fibronectin, which is detected in fairly high concentration (milligram range) by immunoassays, while undetectable in 2D-PAGE gels. Following several experiments with a combination of zwitterionic and chaotropic substances we obtained a good resolution of the protein in gels containing 0.5 M thiourea plus 8 M urea. By this technique, fibronectin was, for the first time, found to be microheterogeneous between pI values of 5.3 and 5.6 . Besides fibronectin we detected three other families of uncharacterized proteins with Mr of 130 000, 110 000 and 34 000 respectively, whose identity and function are currently under investigation.
International Asset Allocation With Regime Shifts

Correlations between international equity market returns tend to increase in highly volatile bear markets, which has led some to doubt the benefits of international diversification. This article solves the dynamic portfolio choice problem of a U.S. investor faced with a time-varying investment opportunity set modeled using a regime-switching process which may be characterized by correlations and volatilities that increase in bad times. International diversification is still valuable with regime changes and currency hedging imparts further benefit. The costs of ignoring the regimes are small for all-equity portfolios but increase when a conditionally risk-free asset can be held. In standard international portfolio choice models such as Sercu (1980) and Solnik (1974a), agents optimally hold the world market portfolio and a series of hedge portfolios to hedge against real exchange rate risk. From the perspective of these models, investors across the world display strongly homebiased asset choices. One popular argument often heard to rationalize the “home bias puzzle” relies on the asymmetric correlation behavior of international equity returns. A number of empirical studies document that correlations between international equity returns are higher during bear markets than during bull markets. 1 If the diversification benefits from international investing are not forthcoming at the time that investors need them the most (when their home market experiences a downturn), the strong case for international investing may have to be reconsidered. Our goal is to formally evaluate this claim. To quantify the effect of these asymmetric correlations on optimal portfolio choice, we need a dynamic asset allocation model that accommodates time-varying correlations and volatilities. In the standard portfolio choice models and their empirical applications [French and Poterba (1991), Tesar and Werner (1995)], correlations
Self-Administered Misoprostol or Placebo Before Intrauterine Device Insertion in Nulliparous Women: A Randomized Controlled Trial

OBJECTIVES: To estimate the effects of self-administered misoprostol compared with placebo before intrauterine device (IUD) insertion in nulliparous women. METHOD: Nulliparous women requesting either the copper T380A or levonorgestrel IUD were randomized to self-administer either 400 mug of misoprostol or placebo (vaginally or buccally) 3-4 hours before the IUD insertion appointment. The primary outcome was health care provider-perceived ease of insertion recorded on a visual analog scale (anchors: 0 extremely easy 100 impossible). Patients completed questionnaires addressing pain using a validated visual analog scale (anchors: 0 none 100 worst imaginable) before insertion immediately postinsertion and before clinic discharge. RESULTS: Of the 108 women enrolled in the study 54 received misoprostol and 54 received placebo. There was no significant difference in perceived ease of insertion between the two groups (25.0 mm [standard error 3.5] compared with 27.4 mm [standard error 3.5] P=.64). Patients who received misoprostol before IUD insertion had significantly higher pain scores before placement (17.1 mm [standard error 3.5] compared with 4.7 mm [standard error 2.0] P=.003). Groups did not differ in perception of pain during IUD insertion (58.4 mm [standard error 3.3] compared with 56.9 mm [standard error 3.0] P=.74). There were two expulsions in the misoprostol group and none in the placebo group. Failed insertions need for adjuvant pain medication and need for cervical dilation or ultrasonographic guidance did not differ between the two groups. CONCLUSION: Self-administered misoprostol before IUD insertion does not ease IUD insertion or reduce patient-perceived pain in nulliparous women. These data do not support the routine use of misoprostol before IUD insertion in nulliparous women. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov www.clinicaltrials.gov NCT00886834. LEVEL OF EVIDENCE: I.
Exploiting hydrodynamic instabilities. Resonant heat transfer enhancement

Abstract We introduce here the concept of resonant heat transfer enhancement based on excitation of shear-layer instabilities present in internal separated flows. Exploitation of natural instabilities requires: creation of a system with separated flow; determination of the system's resonant frequency; and excitation of that frequency with appropriate modulation. The resulting large scale motions lead to significant lateral mixing and correspondingly dramatic heat transfer enhancement. The method is applicable both in laminar and turbulent flows. Results, experimental and numerical, for a subcritieal grooved channel flow and a cross flow around a cylinder are presented. For the case of grooved channel, up to three-fold enhancement of heat transfer is observed when the flow is modulated at the system's natural frequency.
Global health: Why cultural perceptions, social representations, and biopolitics matter

Global health: Why cultural perceptions, social representations, and biopolitics matter, by Mark Nichter, Tuscon, Arizona, The University of Arizona Press, 2008, 268 pp., including notes, US$65.00 ...
Structure and phase transitions of the lanthanide metals

The structures and phase transitions of the lanthanide metals can be related to f orbital contributions to the bonding. With increasing availability of the f orbitals the structure sequence hexagonal closest packed, double hexagonal closest packed, δ-samarium, cubic closest packed, and body-centered cubic is observed. Increases in temperature and/or pressure result in an increased availability of the f orbitals resulting in predictable phase transitions.
Pharmacologic preservation of the hemostatic system during cardiac surgery.

Abstract Bleeding after cardiac surgery remains a major potential problem. Numerous pharmacologic approaches to attenuating hemostatic system activation in cardiac surgery patients have been studied to further improve patient management. Therapeutic approaches studied include inhibiting thrombin generation or activation, preserving platelet function, and decreasing the need for transfusion of allogeneic blood products. Pharmacologic approaches to reduce bleeding and transfusion requirements in cardiac surgery patients are based on either preventing or reversing the defects associated with the CPB-induced coagulopathy. The increasing use of platelet inhibitors (clopidogrel and IIb/IIIa receptor antagonists) and new anticoagulants (low–molecular weight heparins, pentasaccharide, recombinant hirudin, bivalirudin, and argatroban) also pose interesting problems in managing cardiac surgery patients. Aprotinin and lysine analogues (ϵ-aminocaproic acid and tranexamic acid) have become mainstay therapeutic agents to prevent bleeding and the potential need for allogeneic transfusion. Newer therapies that are important to consider include the potential of recombinant activated factor VIIa as a therapy for refractory bleeding after cardiac surgery.
Photothermal spectroscopy as a sensitive spectroscopic tool

Photothermal spectroscopy has emerged as a popular spectroscopic technique over the past decade because it is convenient and sensitive. It is convenient since a wide range of samples of all phases from highly opaque, light- scattering or reflective to highly transparent materials can be measured to some level of accuracy over a broad spectral range with little or no sample preparation. It is sensitive since, in principle, it is a 'zero background' technique, unlike the tradition extinction technique to measure absorption. However, in practice, various sources of noises become significant when the absorption approaches the part-per-million level or below, and various considerations of noise suppression and signal enhancement are essential to exploit photothermal spectroscopy, in particular, photoacoustic spectroscopy and probe-beam deflection spectroscopy. The authors consider here the physical basis for signal generation and enhancement, as well as noise sources and reduction schemes for pulsed and continuous-modulated excitations. Examples of experimental techniques are given to illustrate the points
The gas amplification factor in xenon filled proportional counters

Abstract The gas amplification factor in a variety of commercial xenon filled proportional counters has been found to obey equally well both the Diethorn equation and the Zastawny equation over the range of variables studied. Constants appropriate to each equation have been determined for both Xe-5%CO 2 and Xe-10%CH 4 fill gases.
The cuticular pattern in an insect: The behaviour of grafts in segmented appendages

Abstract Skin-grafting experiments have been performed on the appendages of Rhodnius and Triatoma. The formation of folds of cuticle and a changed orientation of the bristles after moulting were used as criteria for incompatibility. Grafts which did not cause these changes were said to ‘take’. Grafts implanted in a way which disturbs the relative position in the axis of the segment do not take. Grafts moved around a segment take. Grafts between different segments of appendages take, provided they occupy similar positions in the axis of the segment. Grafts between the same segment in different appendages also take, provided they are in similar relative positions in the axis of the segment. The results are consistent with there being a gradient repeating in segmental appendages in a way comparable to that postulated to exist in the abdominal segments. The parallel between the gradient described here and the ‘prepattern’ concept derived from genetics is discussed.
Influence of absorbable dusting powders on wound infection.

Abstract Surgical glove dusting powders are commonly used as mold-release agents and to facilitate donning. Cornstarch and CaCO 3 are commonly used absorbable dusting powders. This experimental study demonstrates that these absorbable dusting powders significantly potentiate bacterial growth and enhance a wound's inflammatory response. The infection-potentiating effects of CaCO 3 are significantly greater than those of cornstarch.
Reduction of False Positives by Internal Features for Polyp Detection in CT-Based Virtual Colonoscopy

In this paper, we present a computer-aided detection (CAD) method to extract and use internal features to reduce false positive (FP) rate generated by surface-based measures on the inner colon wall in computed tomographic (CT) colonography. Firstly, a new shape description global curvature, which can provide an overall shape description of the colon wall, is introduced to improve the detection of suspicious patches on the colon wall whose geometrical features are similar to that of the colonic polyps. By a ray-driven edge finder, the volume of each detected patch is extracted as a fitted ellipsoid model. Within the ellipsoid model, CT image density distribution is analyzed. Three types of (geometrical, morphological and textural) internal features are extracted and applied to eliminate the FPs from the detected patches. The presented CAD method was tested by a total of 153 patient datasets in which 45 patients were found with 61 polyps of sizes 4–30 mm by optical colonoscopy. For a 100% detection sensitivity (on polyps), the presented CAD method had an average FPs of 2.68 per patient dataset and eliminated 93.1% of FPs generated by the surface-based measures. The presented CAD method was also evaluated by different polyp sizes. For polyp sizes of 10–30 mm, the method achieved mean number of FPs per dataset of 2.0 with 100% sensitivity. For polyp sizes of 4–10 mm, the method achieved 3.44 FP per dataset with 100% sensitivity.
The cytoarchitecture of gabaergic neurons in rat spinal cord

Glutamic acid decarboxylase (GAD), the enzyme that synthesizes the transmitter gamma-aminobutyric acid (GABA), has previously been localized within synaptic terminals in rat spinal cord by immunocytochemistry. In the present study, GAD was localized within the somata and dendrites of GABA neurons following colchicine injections into rat lumbar spinal cord. All regions of the spinal gray matter contained GAD-positive somata except the motoneuron pools (lamina IX). GAD-positive somata also were observed in the ependymal layer and in the dorsolateral funiculus. Small GAD-positive somata, averaging 9 X 13 micrometer in size, were located in laminae I-III, and the size of GAD-positive somata increased for cells located in progressively more ventral laminae, reaching a maximum in lamina VII where somal size averaged 12 X 19 micrometer. Lamina I contained two classes of GAD-positive cell bodies; lenticular shaped, intermediate size neurons that were reminiscent of stalked cells, and a smaller cell type that was elongated in the sagittal plane. GAD-positive somata in laminae II and III had the size and position of islet cells. In laminae IV-VI, GAD-positive somal profiles averaged 12 X 17 micrometer in size. Lamina IV neurons were concentrated along laminar edges, while those in laminae V and VI were distributed more homogeneously. In lamina VIII, GAD-positive cell bodies appeared in groups of 3 or 4 and were smaller than those in lamina VII. Lamina X contained GAD-positive somal profiles averaging 12 X 16 micrometer in size. In the ependymal layer, there were two types of cerebrospinal fluid (CSF)-contacting neurons that contained GAD; one spherical and the other elongated. Both types sent extensions into the central canal where these processes expanded into 4-5 micrometer-wide end bulbs. CSF-contacting cells with sizes and shapes similar to the GAD-positive ones were seen to receive synapses in electron micrographs. The widespread distribution of GABA neurons in spinal cord was suggestive of diverse functions for these cells, encompassing conventional synaptic roles and, perhaps, an involvement in hormonally modulated communication via GABAergic, CSF-contacting neurons.
27 PEDIATRIC EMERGENCY ROOM UTILIZATION BY DIAGNOSIS AND SEX

A previous study of utilization patterns in the Wyler Children's Hospital Emergency Room established that males consistently visit more often than females. Data collected from 1807 consecutive visits from August 1 thru August 15, 1977 were reviewed by diagnosis and sex to determine if particular disease categories account for this difference. 53.2% of the visits studied were male while the population served was 50.5%. This difference was significant at the p <.003 level. Diagnoses reviewed showed a male predominance for simple lacerations with 67 of 107 visits (p=.016) and acute asthmatic episodes with 58 of 84 visits (p <.003). These were the third and sixth most common diagnoses made respectively. None of the other common diagnostic categories demonstrated a statistically significant difference from the population served. Urinary tract infections which accounted for only 14 visits during the study were strongly weighted toward females with 13 (p=.003). These data confirm the observation that males use the emergency room more than females. During the study period, this difference was attributable to the larger number of males requiring treatment for acute asthmatic episodes and simple lacerations.
Radiofrequency catheter ablation in the treatment of supraventricular tachycardia in the elderly

Abstract Objectives . The purpose of this study was to evaluate the efficacy and safety of radiofrequency catheter ablation for the treatment of supraventricular tachycardias in an elderly (≥70 years of age) group of patients. Background . Supraventricular tachycardias are the most common form of cardiac arrhythmia and affect all age groups. Although usually well tolerated in youth, supraventricular tachycardias may be associated with disabling symptoms and have lifethreatening potential 10 the elderly. In addition, antiarrhythmic agents are less well tolerated and may be associated with a higher incidence of toxicity in the elderly. Methods . From May 1989 to March 1993, 454 patients underwent a radiofrequency catheter ablation procedure at the University of California, San Francisco, for the treatment of symptomatic supraventricular tachycardia. Sixty-seven of these patients were ≥70 years of age and constituted the study group. Patients underwent one of the following catheter ablation procedures: complete atrioventricular (AV) junctional ablation for ventricular rate control in patients with atrial fibrillation (37 patients), AV node modification for the treatment of AV node reentrant tachycardia (17 patients), accessory pathway ablation (9 patients), ablation of the “slow zone” to cure atrial flutter (4 patients) and atrial tachycardia ablation (1 patient). One patient underwent ablation for both AV node reentrant tachycardia and atrial flutter. Results . Success was achieved in 67 (98.5%) of 68 ablation procedures. There were no procedural or early deaths. The overall complication rate was 7.4%, and only one patient (1.5%) had long-term sequelze (permanent cardiac pacing for complete heart block). At a mean (±SD) follow-np of 22.1 ± 12.9 months, 63 (94%) of 67 patients were alive, with no antiarrhythmic agents for the treatment of their presenting arrhythmia. Conclusions . In this series radiofreqnency catheter ablation appears to be an effective and safe treatment option for elderly patients (≥70 yean of age) with a variety of symptomatic, drug-resistant supraventricular tachycardias. Because of the high incidence of severe symptoms associated with tachycardic episodes, the expense and the possible severe proarrhythmic problems associated with antiarrhythmic medications in this age group, catheter ablation may be considered an early rather than a “last resort” treatment option.
Partial nephrectomy for renal cortical tumors: pathologic findings and impact on outcome.

Abstract Objectives To review the experience with partial nephrectomy for the diagnosis and treatment of renal cortical tumors at the Memorial Sloan-Kettering Cancer Center with a particular focus on the histologic findings at the time of surgery. Methods The results of 292 consecutive partial nephrectomies were reviewed. Demographic data, perioperative complications, and disease status were recorded. The specimens were reviewed for histologic subtyping in accordance with the Heidelberg classification for renal cortical tumors. The probabilities of recurrence and disease-specific death were assessed with the cumulative incidence estimate. Results The median follow-up was 25.3 months (range 1 to 155). A total of 246 patients (87%) were diagnosed with a renal cortical tumor, 1 patient (less than 1%) was diagnosed with another cancer, and 34 (12%) were diagnosed with benign lesions. The most frequent histologic finding among the renal cortical tumor subgroup was conventional clear cell carcinoma in 148 cases (51%), followed by papillary carcinoma in 54 (18%), oncocytoma in 32 (11%), and chromophobe carcinoma in 21 (7%). Bilateral disease and multifocality were most prevalent in the conventional and papillary subtypes, respectively. The 5-year probability of recurrence and disease-specific death was 12% and 8%, respectively, for the conventional clear cell type. No local or distant disease recurrence was observed in any other renal cortical tumor subtypes. Conclusions Partial nephrectomy should be considered a diagnostic and therapeutic surgical approach for renal cortical masses. Conventional clear cell carcinoma is the most frequent histologic subtype and is associated with a less favorable outcome compared with papillary carcinoma and chromophobe carcinoma. Radical nephrectomy for renal lesions that could be removed by partial nephrectomy will risk renal impairment in a substantial proportion of patients with benign disease.
Retrograde facilitation of memory by triazolam: effects on automatic processes.

Rationale: Retrieval processes have been implicated as a potential mechanism by which benzodiazepines can produce retrograde memory facilitation. Objectives: This study tested the degree to which benzodiazepine-induced retrograde facilitation of memory was due to an enhancement of automatic retrieval processes. Methods: Forty healthy adults were randomly assigned to one of three dose conditions (double-blind), under which they received 0.0 mg (placebo), 0.125 mg, or 0.25 mg of the short-acting benzodiazepine triazolam (Halcion). Subjects studied a list of words just prior to dose administration. One hour after dose administration, subjects performed a word-stem completion task which tested their retrieval of the studied words. A process-dissociation procedure was used to estimate the degree to which retrieval was under the influence of memory processes that were automatic (i.e., unintentional) versus controlled (i.e., intentional). Results: Subjects who received active doses of triazolam displayed a greater probability of using studied words as stem completions. Estimates of memory processes showed a greater influence of automatic influences during memory retrieval under triazolam doses. Conclusions: The findings indicate that retrograde memory facilitation following benzodiazepine administration does not necessarily reflect an improved ability to intentionally retrieve information but could instead reflect increased responsiveness to cues that automatically elicit retrieval of pre-drug information.
Contextual Poverty, Nutrition, and Chronic Kidney Disease

Nutrition plays an important role in CKD outcomes. One of the strongest factors that affects nutrition is socioeconomic status as evidenced by the large body of epidemiologic data showing that income and education are directly associated with diet quality. Apart from individual-level markers of socioeconomic status such as income and education, contextual factors such as availability of and transportation to food outlets that provide healthy food options and the density of fast-food restaurants within particular regions markedly affect the ability of individuals to comply with nutrition recommendations. This is particularly true for nutrition guidelines most specific to individuals with CKD such as the consumption of protein, saturated fat, sodium, and phosphorus, all of which have been shown to affect CKD health and are influenced by the availability of healthy food options within individual neighborhood food environments. Because of the strong association of contextual poverty with the diet quality, any serious attempt to improve the diet of CKD patients must include a discussion of the environmental barriers that each individual faces in trying to access healthy foods, and health care providers should take account of these barriers when tailoring specific recommendations.
Topological Consistency in Skeletal Modeling With Convolution Surfaces

A skeletal model consists of a collection of geometric primitives, such as points, lines, and triangles, that specifies the topology of an object. The skeleton is can be used to define surfaces, resulting in a solid model of the object. Of the various surface models that have been used for skeletal models, the convolution surface has some attractive properties. The convolution surface is an implicit surface that has been formulated for various geometric primitives such as lines, triangles, etc. Modeling with convolution surfaces guarantees a continuous and smoothly blended surface that is relatively easy to deform and intuitive to specify. However, when two skeleton elements are placed close to each other, unwanted blending can occur and the topology of the final shape becomes difficult to control. To be useful in conceptual engineering design, a skeletal modeler must ensure that the topology of surfaces generated agrees with that of the skeleton. Ensuring a match between the topology of the convolution surface and its skeleton is a challenging problem. In this paper, we propose a method based on Morse theory for ensuring topological consistency. By adjusting the parameters of the convolution surfaces, the topology of the final composite surface can be forced to match its root skeleton.© 2008 ASME
Reduction Potential of the Sulfhydryl Radical: Pulse Radiolysis and Laser Flash Photolysis Studies of the Formation and Reactions of ·SH and HSSH·-in Aqueous Solutions

Formation and reactions of the ·SH/·S- and HSSH·-/HSS·2- radicals in aqueous solutions have been studied by excimer laser flash photolysis and by pulse radiolysis. Acidic H2S solutions can be photolyzed with 193 nm laser pulses and produce a transient species with λmax at 240 nm, ascribed to the ·SH/·S- radical. Solutions of SH- can be photolyzed also with 248 nm laser pulses to produce the ·SH/·S- radical. The same radical is formed by oxidation of SH- ions with SO4·- and CO3·- radicals. At pH > 5, ·SH/·S- reacts with SH- (kf = 4 × 109 L mol-1 s-1, kr = 5 × 105 s-1) to form HSSH·-/HSS·2-, with λmax at 380 nm. Both ·SH/·S- and HSSH·-/HSS·2- react rapidly with O2; the former produces SO2·- (k = 5 × 109 L mol-1 s-1), and the latter produces O2·- (k = 4 × 108 L mol-1 s-1). Both radicals react with olefinic compounds. The monomeric radical oxidizes Fe(CN)64-, SO32-, ClO2-, and chlorpromazine. The dimeric radical is a weaker oxidant toward ferrocyanide but reduces N-methylpyridinium compounds. The reduction po...
Competing through development capability in a manufacturing-based organization

I n a competitive environment that is global, intense, and dynamic, developing new products and processes is increasingly a foc,l point of competition. Firms that get to market faster and more efficiently with products that are well matched to the needs and expectations of target customers create significant competitive leverage. Firms that are slow to market with products that match neither customer expectations nor the products of their rivals are destined to see their market position erode and financial performance falter. In a turbulent environment, excelling at product and process development has become a requirement for being a player in the competitive game; doing development extraordinarily well can provide a sustainable competitive advantage.
On the elastic stabilization of precipitates against coarsening under applied load

Abstract A simple procedure is developed for examining the stability against coarsening of two misfitting spherical precipitates subjected to an applied uniaxial tensile stress. Analytic expressions are obtained defining regions of stability and metastability. It is found that the applied stress can act to stabilize the precipitates for certain precipitate orientations with respect to the applied stress and destabilize the precipitates for other orientations. Conditions are also delineated in which small precipitates should be expected to grow at the expense of larger precipitates. These results are found to be in agreement with experiment for an applied stress field less than a threshold stress.
Biomarkers of AKI: A Review of Mechanistic Relevance and Potential Therapeutic Implications

AKI is a common clinical condition associated with a number of adverse outcomes. More timely diagnosis would allow for earlier intervention and could improve patient outcomes. The goal of early identification of AKI has been the primary impetus for AKI biomarker research, and has led to the discovery of numerous novel biomarkers. However, in addition to facilitating more timely intervention, AKI biomarkers can provide valuable insight into the molecular mechanisms of this complex and heterogeneous disease. Furthermore, AKI biomarkers could also function as molecular phenotyping tools that could be used to direct clinical intervention. This review highlights the major studies that have characterized the diagnostic and prognostic predictive power of these biomarkers. The mechanistic relevance of neutrophil gelatinase–associated lipocalin, kidney injury molecule 1, IL-18, liver-type fatty acid–binding protein, angiotensinogen, tissue inhibitor of metalloproteinase-2, and IGF-binding protein 7 to the pathogenesis and pathobiology of AKI is discussed, putting these biomarkers in the context of the progressive phases of AKI. A biomarker-integrated model of AKI is proposed, which summarizes the current state of knowledge regarding the roles of these biomarkers and the molecular and cellular biology of AKI.
Spectral responses of sustaining fibers in the optic tracts of crayfish (Procambarus)

Spectral response curves were recorded for 60–70 individual sustaining fibers in the optic nerve of the crayfish Procambarus. These cells belong to at least 8 of the 14 classes of sustaining fibers described by Wiersma and Yamaguchi (1966) on the basis of receptive fields. About 90 percent of the cells receive predominant input from yellow-green receptors and are maximally sensitive at 560 to 570 nm; a much smaller number receive principal input from blue receptors and are maximally sensitive near 460 nm.
Removal and formation of chlorinated triclosan derivatives in wastewater treatment plants using chlorine and UV disinfection

Triclosan, a common antimicrobial agent, may react during the disinfection of wastewater with free chlorine to form three chlorinated triclosan derivatives (CTDs). This is of concern because the CTDs may be photochemically transformed to tri- and tetra-chlorinated dibenzo-p-dioxins when discharged into natural waters. In this study, wastewater influent, secondary (pre-disinfection) effluent, and final (post-disinfection) effluent samples were collected on two occasions each from two activated sludge wastewater treatment plants, one using chlorine disinfection and one using UV disinfection. Concentrations of triclosan and three CTDs were determined using ultra performance liquid chromatography-triple quadrupole mass spectrometry with isotope dilution methodology. Triclosan and the CTDs were detected in every influent sample at levels ranging from 453 to 4530 and 2 to 98 ng L(-1), respectively, though both were efficiently removed from the liquid phase during activated sludge treatment. Triclosan concentrations in the pre-disinfection effluent ranged from 36 to 212 ng L(-1), while CTD concentrations were below the limit of quantification (1 ng L(-1)) for most samples. In the treatment plant that used chlorine disinfection, triclosan concentrations decreased while CTDs were formed during chlorination, as evidenced by CTD levels as high as 22 ng L(-1) in the final effluent. No CTDs were detected in the final effluent of the treatment plant that used UV disinfection. The total CTD concentration in the final effluent of the chlorinating treatment plant reached nearly one third of the triclosan concentration, demonstrating that the chlorine disinfection step played a substantial role in the fate of triclosan in this system.
RELATIONSHIP BETWEEN ACTIVITY OF PYRUVATE KINASE AND AGE OF THE NORMAL HUMAN ERYTHROCYTE.

MATURE erythrocytes of human beings derive energy chiefly through anaerobic glycolysis. Pyruvate kinase catalyses a key1,2, adenosine triphosphate-generating glycolytic reaction. We have examined the relationship between the activity of pyruvate kinase and the age of the normal human red cell.
Chaotic emergence and the language of thought

Abstract The purpose of this paper is to explore the merits of the idea that dynamical systems theory (also known as chaos theory) provides a model of the mind that can vindicate the language of thought (LOT). I investigate the nature of emergent structure in dynamical systems to assess its compatibility with causally efficacious syntactic structure in the brain. I will argue that anyone who is committed to the idea that the brain's functioning depends on emergent features of dynamical systems should have serious reservations about the LOT. First, dynamical systems theory casts doubt on one of the strongest motives for believing in the LOT: principle P, the doctrine that structure found in an effect must also be found in its cause. Second, chaotic emergence is a double‐edged sword. Its tendency to cleave the psychological from the neurological undermines foundations for belief in the existence of causally efficacious representations. Overall, a dynamic conception of the brain sways us away from realist co...
The Acoustic Results of a United Technologies Scale Model Helicopter Rotor Tested at DNW

In a major cooperative program between U.S. Government agencies (represented by the U.S. Army Aeroflightdynamics Directorate and NASA Ames and Langley Research Centers) and United Technologies Corp., a 1/6 geometrically and aeroelastically scaled UTC model helicopter rotor was tested in the open-jet anechoic test section of the Duits-Nederlandse Windtunnel in the Netherlands. As the fourth entry under the Aerodynamic and Acoustic Testing of Model Rotors Program, several comprehensive acoustic and aerodynamic databases were obtained relating the important aerodynamic phenomena to both the near- and far-field acoustic radiation. In particular, high speed impulsive noise and blade-vortex interaction are of primary interest. This paper provides an initial summary of the acoustic measurements acquired for some of the different configurations tested. A review of the baseline swept tip rotor acoustic characteristics in the regimes of high speed forward flight, where high speed impulsive noise dominates, and low speed descent, where severe blade vortex interaction noise occurs, is presented. The trends of these primary noise sources are studied as the first step in validating the data for release and application.