cssi/SciSciGPT-SciSciNet huggingface dataset:
Hybrid TE-TEA CO_2 laser

The author describes a new form of hybrid TE-TEA carbon dioxide laser for heterodyne applications in which the cw section is replaced by a transversely excited, pulsed, low-pressure section. (AIP)
Reply to comment by William P. Johnson et al. on “Transport and fate of bacteria in porous media: Coupled effects of chemical conditions and pore space geometry”

[1] We are grateful for this opportunity to address the comment of Johnson et al. [2009] on our manuscript. Their comment concerns the nature of colloid association with solid surfaces via the secondary energy minimum. There are currently different opinions in the literature on this topic. Johnson et al. [2007] have assumed that colloids associated with collector surfaces via the secondary minimum are ‘‘freely mobile’’ in the presence of fluid drag and can therefore only be immobilized in stagnation regions. In contrast, we have applied a torque balance approach to determine locations where colloid retention is theoretically possible when the driving (hydrodynamic) torque is less than the resisting (adhesive) torque [Bradford et al., 2007; Torkzaban et al., 2007, 2008]. Each of these points of view will be discussed below.
HideM: Protecting the Contents of Userspace Memory in the Face of Disclosure Vulnerabilities

Memory disclosure vulnerabilities have become a common component for enabling reliable exploitation of systems by leaking the contents of executable data. Previous research towards protecting executable data from disclosure has failed to gain popularity due to large performance penalties and required architectural changes. Other research has focused on protecting application data but fails to consider a vulnerable application that leaks its own executable data.In this paper we present HideM, a practical system for protecting against memory disclosures in contemporary commodity systems. HideM addresses limitations in existing advanced security protections (e.g., fine-grained ASLR, CFI) wherein an adversary discloses executable data from memory, reasons about protection weaknesses, and builds corresponding exploits. HideM uses the split-TLB architecture, commonly found in CPUs, to enable fine-grained execute and read permission on memory. HideM enforces fine-grained permission based on policy generated from binary structure thus enabling protection of Commercial-Off-The-Shelf (COTS) binaries. In our evaluation of HideM, we find application overhead ranges from a 6.5% increase to a 2% reduction in runtime and observe runtime memory overhead ranging from 0.04% to 25%. HideM requires adversaries to guess ROP gadget locations making exploitation unreliable. We find adversaries have less than a 16% chance of correctly guessing a single gadget across all 28 evaluated applications. Thus, HideM is a practical system for protecting vulnerable applications which leak executable data.
Copper adsorption by esterified and unesterified fractions of Sphagnum peat moss and its different humic substances

Abstract The Cu(II) binding properties of Canadian Sphagnum peat moss, humic acid and humin extracted from the peat moss were investigated. Batch pH profile experiments indicated that the adsorption of Cu(II) is pH dependent. At pH 4.0 and 5.0 about 99% of Cu(II) was bound by all three biomasses. Time-dependent experiments showed that the binding of Cu(II) is very rapid. The Cu(II) binding capacities at pH 4.0 were 16.1 mg per gram peat moss, 28.2 mg per gram humic acid, and 17.9 mg per gram humin. More than 90% of Cu(II) bound to the biomasses was recovered by treatment with 0.1 M HCl. We showed that carboxyl groups on these humic substances are responsible for some of the Cu(II) binding by esterifying them with methanol in the presence of trimethoxymethane (trimethyl orthoformate) and observing a decrease in Cu(II) binding. Infrared analysis confirmed the esterification and base hydrolysis of the esterified biomasses corroborated that esterification (and not degradation) had occurred since the metal-binding ability was regained. Our results provide important information on the interaction of Cu(II) ions with Sphagnum peat moss and its humic fractions. This may have practical applications for the removal of hazardous copper ions from contaminated water supplies.
Characterization of nanoprobe uptake in single cells: spatial and temporal tracking via SERS labeling and modulation of surface charge.

Abstract A critical aspect for use of nanoprobes in biomedical research and clinical applications involves fundamental spatial and temporal characterization of their uptake and distribution in cells. Raman spectroscopy and two-dimensional Raman imaging were used to identify and locate nanoprobes in single cells using surface-enhanced Raman scattering detection. To study the efficiency of cellular uptake, silver nanoparticles functionalized with three different positive-, negative-, and neutrally charged Raman labels were co-incubated with cell cultures and internalized via normal cellular processes. The surface charge on the nanoparticles was observed to modulate uptake efficiency, demonstrating a dual function of the surface modifications as tracking labels and as modulators of cell uptake. These results indicate that the functionalized nanoparticle construct has potential for sensing and delivery in single living cells and that use of surface-enhanced Raman scattering for tracking and detection is a practical and advantageous alternative to traditional fluorescence methods. From the Clinical Editor Cell labeling and tracking methods are commonly required in biomedical research. This paper presents specific functionalized nanoparticle constructs with potential for sensing and delivery in single living cells. The use of surface-enhanced Raman scattering enables tracking and detection of these cells as a practical alternative to traditional fluorescence methods.
Gravity Studies of C. elegans

Caenorhabditis elegans is an important model organism in many fields of research. This microscopic worm possesses a primitive nervous system composed of just 302 neurons that shares many features across various species. Despite the simplicity of its nervous system, C. elegans exhibits many sensory modalities and behaviors, allowing researchers to perform relatively simple yet highly insightful experiments that probe both the evolution and function of the nervous system. An important unresolved question is whether or not C. elegans detects or responds to gravity. The detection of gravity is a poorly understood phenomenon despite its ubiquity. By analyzing gravitational field detection in C. elegans, we will improve our understanding of how more complex nervous systems are capable of detecting and responding to the force of gravity.Comparing the velocities of living and dead C. elegans, it is apparent that living samples were actively swimming in the direction of gravity. their average downward velocity was twice that of our dead samples, suggesting that the C. elegans nervous system is capable of detecting gravity.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Quantitative determination of the oxidation state of iron in biotite using X-ray photoelectron spectroscopy: I. Calibration

Abstract X-ray photoelectron spectroscopy (XPS) analyses of Fe(III)/ΣFe were calibrated with nine single crystals of biotite of known Fe(III)/ΣFe content. Peak shape parameters for the component Fe2+ and Fe3+ Fe 3p peaks were obtained by a constrained least squares fitting method that minimized the difference between Fe(IIl)/EFe determined by XPS and wet chemistry /electron microprobe (WCEM) analyses. Fe2+ and Fe3+ peak separation was estimated from the separation of minima in the second derivative of Fe 3p spectra. The single set of derived peak parameters yielded a good linear correlation (r = 0.87) between XPS and WCEM values over the sample range of 2–20% Fe(RI)/ΣFe. Target transformation factor analysis of a time series of spectra for a sample displaying progressive oxidation during XPS analysis resulted in Fe2+ and Fe3+ component peak shapes largely consistent with the constrained least squares fitting method. Peak asymmetry for the Fe3+ component was the only parameter that differed for the two methods. Beam damage, which appeared to be restricted to three single crystals with low ΣFe, low Fe/Mg, and high Fe(II)/ΣFe, caused increases in Fe(III)/ΣFe that were proportional to the duration of sample exposure.
The 1.8 Å crystal structure and active-site architecture of β-ketoacyl-acyl carrier protein synthase III (FabH) from Escherichia coli

Abstract Background: β-Ketoacyl-acyl carrier protein synthase III (FabH) initiates elongation in type II fatty acid synthase systems found in bacteria and plants. FabH is a ubiquitous component of the type II system and is positioned ideally in the pathway to control the production of fatty acids. The elucidation of the structure of FabH is important for the understanding of its regulation by feedback inhibition and its interaction with drugs. Although the structures of two related condensing enzymes are known, the roles of the active-site residues have not been experimentally tested. Results: The 1.8 A crystal structure of FabH was determined using a 12-site selenium multiwavelength anomalous dispersion experiment. The active site (Cys112, His244 and Asn274) is formed by the convergence of two α helices and is accessed via a narrow hydrophobic tunnel. Hydrogen-bonding networks that include two tightly bound water molecules fix the positions of His244 and Asn274, which are critical for the decarboxylation and condensation reactions. Surprisingly, the His244→Ala mutation does not affect the transacylation reaction suggesting that His244 has only a minor influence on the nucleophilicity of Cys112. Conclusions: The histidine and asparagine active-site residues are both required for the decarboxylation step in the condensation reaction. The nucleophilicity of the active-site cysteine is enhanced by the α-helix dipole effect, and an oxyanion hole promotes the formation of the tetrahedral transition state.
Calcium-sensing receptor and calcimimetic agents

Calcium-sensing receptor and calcimimetic agents. Recognizing the role of the extracellular calcium-sensing receptor (CaR) in mineral metabolism greatly improves our understanding of calcium homeostasis. The biology of the low affinity, G-protein-coupled CaR and the effects of its activation in various tissues are reviewed. Physiological roles include regulation of parathyroid hormone (PTH) secretion by small changes in ionized calcium (Ca2+) and control of urinary calcium excretion with small changes in blood Ca2+. The CaR also affects the renal handling of sodium, magnesium and water. Mutations affecting the CaR that make it either less or more sensitive to Ca2+ cause various clinical disorders; heterozygotes of mutations causing the CaR to be less sensitive to extracellular Ca2+ cause familial hypocalciuric hypercalcemia, while the homozygous form results in severe infantile hyperparathyroidism. Mutations causing increased sensitivity of the CaR to extracellular Ca2+ produce hereditary forms of hypoparathyroidism. Disorders, such as primary and secondary hyperparathyroidism, may exhibit acquired abnormalities of the CaR. Calcimimetic drugs, which amplify the sensitivity of the CaR to Ca2+, can suppress PTH levels, leading to a fall in blood Ca2+. Experiences with this agent in patients with secondary and primary hyperparathyroidism and parathyroid carcinoma are summarized. In animals and humans with hyperparathyroidism, this agent produces a dose-dependant fall in PTH and blood Ca2+, with larger doses causing more sustained effects. The treatment has been short-term except for one patient followed for more than 600 days for parathyroid carcinoma; nonetheless the drug did not cause major side-effects and appears to be safe. Further long-term controlled studies are needed with calcimimetic agents of this type.
Cerebral Energy Levels during Trimethaphan-induced Hypotension in the RatEffects of Light versus Deep Halothane Anesthesia

Hypotension may be expected to produce less perturbation of metabolism in the brain when cerebral metabolic rate is lowered by deep anesthesia. Male Wistar rats having unilateral carotidartery ligation were exposed to mean arterial pressure (MAP) of 40 torr for 22 min by an intravenous infusion of trimethaphan during anesthesia with halothane, 0.6 or 2 per cent, in oxygen. Cortical tissue metabolite levels on the side of the ligated carotid artery were more abnormal in rats receiving halothane, 0.6 per cent, than in those receiving halothane, 2 per cent. Values at halothane, 0.6 per cent, were adenosine triphosphate (ATP), 1.71 +/- 0.05 (+/-SEM) mumol/g, phosphocreatine (PCr) 1.97 +/- 0.07 mumol/g. and lactate 16.5 +/- 5.1 mumol/g; corresponding values at halothane, 2 per cent, were ATP 2.27 +/- 0.02, PCr 4.02 +/- 0.23, and lactate 4.75 +/- 0.9 mumol/g. ATP and PCr values were significiantly lower (P less than 0.05) and the lactate value was significantly higher with halothane, 0.6 per cent, than with halothane 2 per cent. Cerebral oxygen consumption decreased 47 per cent in rats anesthetized with halothane, 2 per cent. Preservation of cortical metabolite levels in deeply anesthetized animals suggests a protective effect of cerebral metabolic depression.
Glycoprotein IIb/IIIa inhibitors and the guidelines for treatment of non–ST-elevation myocardial infarction

In a recent study published in the Journal [(1)][1]Peterson et al. found that with regard to use of glycoprotein (GP) IIb/IIIa inhibitors there was a low adherence to American College of Cardiology/American Heart Association guidelines (published in 2000) for treatment of non–ST-elevation
Creativity support: the mixed-initiative composition space

Creativity support is an important and challenging emerging area of research. combinFormation is being developed as a tool to support creativity through a mixed-initiative composition space. The system combines searches and information feeds, representing relevant information collections as compositions of image and text surrogates. The composition space affords human manipulation. This method has been shown to support information discovery in The Design Process, an interdisciplinary undergraduate course. In this demo, we demonstrate how combinFormation can be used to explore and discover information in digital libraries such as ACM Digital Library and the International Children's Digital Library.
A THEORETICAL STUDY OF THE LIMITING HEAT TRANSFER COEFFICIENT IN FLUIDIZED BEDS

Abstract A new model is presented to describe the heat transfer process occurring in fluidized beds under the limiting condition of very short contact times between the heat transfer surface and the emulsion phase. Unlike other work in this area the proposed model assumes that the particles are in constant motion close to the surface throughout the heat transfer process. The effect of the non-continuum gas film assumption (the Smoluchowski effect) when particles are very close to the surface is found to be of secondary importance when compared with the movement of particles close to the surface. Expressions for both the instantaneous and time averaged heat transfer coefficients for individual and a spatial distribution of parlicles are presented.
Cosmetic selection in the sensitive-skin patient

The incidence of sensitive skin is increasing with great rapidity in the United States and Japan. This increase may be due in part to recognition of the condition, an increase in the number of skin products used on a daily basis by persons in developed countries, and other unidentified influences. Sensitive skin may be due to enhanced immune responsiveness, altered neurosensory input, and/or diminished barrier function. Guidelines for cosmetic and skin care product selection in the sensitive-skin patient include a paucity of ingredients, a minimum of potential allergens, a reduction in cutaneous irritants, and restoration of the cutaneous barrier. This article presents a thought pattern for addressing cosmetics issues in the sensitive-skin patient.
Guidance, Navigation, and Control Technology Assessment for Future Planetary Science Missions

Future planetary explorations envisioned by the National Research Council's (NRC's) report titled Vision and Voyages for Planetary Science in the Decade 2013-2022, developed for NASA Science Mission Directorate (SMD) Planetary Science Division (PSD), seek to reach targets of broad scientific interest across the solar system. This goal requires new capabilities such as innovative interplanetary trajectories, precision landing, operation in close proximity to targets, precision pointing, multiple collaborating spacecraft, multiple target tours, and advanced robotic surface exploration. Advancements in Guidance, Navigation, and Control (GN&C) and Mission Design in the areas of software, algorithm development and sensors will be necessary to accomplish these future missions. This paper summarizes the key GN&C and mission design capabilities and technologies needed for future missions pursuing SMD PSD's scientific goals.
LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS ON MOTILE CELLS OF PORPHYRIDIUM PURPUREUM (RHODOPHYTA)1,2

SUMMARY Motile cells of the unicellular red alga, Porphyridium purpureum (Bory) Drew & Ross were studied using light, interference, and electron microscopy. In liquid culture, moving cells possessed a mucilaginous stalk which extended from one end of the cell and tapered to a point. On tin agar surface, distinct trails were left by moving cells. With interference microscopy, the trails appeared to be shallow grooves. Microscopy of shadowed replicas confirmed that moving cells produced a shallow groove as they moved across agar. Ultrastructure observations revealed that cells moving on agar exhibited morphological polarity. Large vesicular elements containing fibrillar material similar to that in the cellular sheath was associated with the posterior area of the motile cells.
ICA mixture model for unsupervised classification of non-Gaussian classes in multi/hyperspectral imagery

Conventional remote sensing classification techniques model the data in each class with a multivariate Gaussian distribution. Inadequacy of such algorithms stems from Gaussian distribution assumption for the class-component densities, which is only an assumption rather than a demonstrable property of natural spectral classes. In this paper, we present an Independent Component Analysis (ICA) based approach for unsupervised classification of multi/hyperspectral imagery. ICA employed for a mixture model, estimates the data density in each class and models class distributions with non-Gaussian structure (i.e. leptokurtic or platykurtic p.d.f.), formulating the ICA mixture model (ICAMM). It finds independent components and the mixing matrix for each class, using the extended information-maximization learning algorithm, and computes the class membership probabilities for each pixel. We apply the ICAMM for unsupervised classification of images from a multispectral sensor - Positive Systems Multi-Spectral Imager, and a hyperspectral sensor - Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). Four feature extraction techniques: Principal Component Analysis, Segmented Principal Component Analysis, Orthogonal Subspace Projection and Projection Pursuit have been considered as a preprocessing step to reduce dimensionality of the hyperspectral data. The results demonstrate that the ICAMM significantly outperforms the K -means algorithm for land cover classification of remotely sensed images.
Thyroid hormones augment catecholamine-stimulated brown adipose tissue thermogenesis in the ovine fetus.

The effects of exogenous changes in thyroid status on in vitro brown adipose tissue (BAT) cellular respiration and thermogenic enzymes (sodium-potassium ATP' ase and alpha-glycerophosphate dehydrogenase) were studied in fetal sheep. Thyroidectomy and insertion of a constant infusion pump followed by 8 days of infusion of either T3 (n = 7) or vehicle (n = 4) were performed in fetal lambs at 119-121 days gestation. The animals were then killed, and perirenal BAT was removed for study. T3 infusion resulted in a mean plasma T3 concentration of 322 +/- 52 ng/dl compared to levels at the limits of detection (9 ng/dl) in the vehicle-infused animals. Basal respiration values with or without ouabain were similar in the two groups. Maximum mean norepinephrine (NE; 10(-6) M)-stimulated respiration (110.2 +/- 11.6 microliter O2/10(6) cells X h) in the T3-treated group was greater than stimulated mean respiration (55.3 +/- 15.6 microliter O2/10(6) cells X h) in the untreated animals (P less than 0.02). NE-stimulated respiration in the presence of ouabain (i.e. nonsodium transport-dependent respiration) was increased in the T3-treated animals (P less than 0.01), while sodium transport-dependent respiration was not different. (Bu)2cAMP-stimulated respiration was greater in the T3-treated group (P less than 0.001), while alpha-glycerophosphate substrate respiration was not different. Mitochondrial alpha-glycerophosphate dehydrogenase and Na-K-ATPase activities were similar. These studies demonstrate that BAT catecholamine-stimulated respiration is influenced by thyroid status in the ovine fetus. The increase in both NE- and (Bu)2cAMP-stimulated respiration suggests a postreceptor effect on intracellular metabolism, though an effect on beta-adrenergic receptors also might have occurred. Neither sodium transport (NA-K-ATPase)-dependent respiration nor mitochondrial alpha-glycerophosphate dehydrogenase appear to be involved. These data suggest that the relative hyperthyroid state that occurs in the newborn of both man and sheep may be important through its effects on BAT metabolism to insure adequate temperature regulation during neonatal adaptation.
Fine structure of the apex of absorptive cells from rat small intestine

These cells were studied in rats, using buffered osmium or aldehyde fixatives followed by osmium. Three groups of filaments and the terminal web were visualized in the apex. One group, seen in aldehyde-fixed tissue formed the cores and rootlets of the microvilli; they showed no continuity with other filaments. Another group formed the desmosomal web, best seen in tissue stained en bloc with uranyl acetate of phosphotungstic acid (PTA). The third group appeared as short, branched profiles between the rootlets after staining with PTA. The terminal web appeared as a dense layer with gaps, extending out to the zonula adhaerens. It seemed to embed the rootlets penetrating between their filaments. Although it appeared granular with the techniques used here, it is probable that at the molecular level the terminal web is formed by elongated branching elements. By supporting the rootlets and microvilli, the terminal web endows the apex with mechanical stability and anchors it to the body of the cell.
Histochemical Localization of Oxidative Enzyme Systems in the Human Anterior Pituitary

The anterior pituitaries of 30 persons were studied histochemically for the activities of DPNH and TPNH diaphorases, and of succinic, lactic, malic, β-hydroxybutyric, glutamic, isocitric and glucose-6-phosphate dehydrogenases. While the qualitative pattern of enzyme activity in the basophils, acidophils and chromophobes was similar, the intensity of the reaction varied with the enzymes and the cell types. The basophilic cells showed the strongest activity in all reacting systems. The acidophils generally had less activity than the basophils but considerably more activity than the chromophobe cells. These results and their significance are discussed.
Computer-Aided Customized Shape Design of an N95 Filtering Facepiece Respirator

A respirator protects its user by sealing the user’s face and filtering hazardous particles from environment. However, faceseal leakages of users-respirators always happen. First, this study investigated a computer-aided technique for designing a well fitted N95 filtering facepiece respirator (FFR) for a subject. The customized N95 FFR includes a customized contact area, a center filtering area, two straps and a nasal clip. Five base contact areas of National Institution for Occupational Safety and Health (NIOSH) headforms were created and the customized contact area was modeled using the mapping relationship between the subject and a NIOSH headform. The center filtering area was designed by considering constraints of N95 FFR shape. Second, this study used simulation-based approaches, including the FE method and computational fluid dynamics (CFD) method, to assess the performance of the customized N95 FFR on the subject. The contact pressure and the faceseal leakage from the subject-customized N95 FFR combination were compared with the results from the subjectexisting N95 FFRs combinations. The comparison showed that the customized N95 FFR provided the subject an optimized contact pressure distribution and no faceseal leakage.
Prinzmetal's Angina: Atypical Angiographic Features of Atypical Angina Pectoris

Clinicians have puzzled over the coronary physiology associated with atypical angina pectoris for the past century. Recent recognition of coronary artery spasm, which has been so thoroughly documented with coronary angiography, has resolved many of these conceptual difficulties. However, several features of coronary artery spasm, both spontaneous and secondary to provocation with ergonovine maleate, remain poorly understood. This paper addresses the management problems associated with spontaneously occurring spasm in the setting of pre-existent atherosclerotic coronary artery disease, angiographically severe spasm unassociated with symptoms of angina pectoris or signs of myocardial ischemia, and the precipitation of angina pectoris by ergonovine maleate administration unaccompanied by demonstrable epicardial coronary artery spasm. The rationale, indications and therapeutic efficacy of a new class of agents known as slow channel inhibitors of calcium antagonists are discussed.
Breast Cancer Mortality in Black and in White Women: A Historical Perspective by Menopausal Status

To examine racial/ethnic differences in breast cancer mortality over time by menopausal status, data from published U.S. Vital Statistics tables (1950-1992) and the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute (1973-1991) were used to calculate age-adjusted breast cancer mortality and incidence rates. Overall, breast cancer mortality rates for white women were relatively stable from 1950 to 1992. In contrast, breast cancer mortality rates for black women increased during this period. Among premenopausal women there was no difference in breast cancer mortality between black and white women from 1950 to about 1975. However, after 1975, mortality rates in black premenopausal women increased, whereas those in white women decreased. Among postmenopausal women, breast cancer mortality was substantially lower in blacks than in whites in 1950. Between 1950 and 1992, rates in blacks increased and eventually exceeded rates in whites, which remained stable during this period. This excess in breast cancer mortality in black women is not explained by changes in breast cancer incidence rates. There is an unexplained epidemic of breast cancer mortality in black women that appears to differ somewhat by menopausal status. Reasons for temporal increases in breast cancer mortality seen only among black women need to be identified, as do reasons for the heterogeneity of trends by menopausal status.
Shorter length dialysis sessions are associated with increased mortality, independent of body weight

Hemodialysis patients have high rates of mortality that may be related to aspects of the dialytic procedure. In prior studies, shorter length dialysis sessions have been associated with decreased survival, but these studies may have been confounded by body size differences. Here we tested whether in-center three-times-weekly hemodialysis patients with adequate urea clearances but shorter dialysis session length is associated with mortality independent of body size. Data were taken from a large national cohort of patients from a large dialysis organization undergoing three-times-weekly in-center hemodialysis. In the primary analysis, patients with prescribed dialysis sessions greater and less than 240min were pair-matched on post-dialysis weight as well as on age, gender, and vascular access type. Compared to prescribed longer dialysis sessions, session lengths less than 240min were significantly associated with increased all-cause mortality (adjusted hazard ratio 1.26). The association was consistent across strata of age, gender, and dialysis post-weight. Secondary analyses found a dose–response between prescribed session length and survival. Thus, among patients with adequate urea clearance, shorter dialysis session lengths are associated with increased mortality independent of body weight.
Influence of gastric inhibitory polypeptide (GIP) and glucose on the regulation of glucagon secretion by pancreatic alpha cells.

The effects of glucose and GIP on glucagon secretion were studied in perifused microdissected murine pancreatic islets. Glucagon levels were determined in effluent samples collected at 1-min intervals by radioimmunoassay using the glucagon-specific antibody, 30 K. There was no significant difference in the total amount (7740 ± 212 pg vs 8630 ± 36 pg, n = 10) of glucagon secreted over a 20 min period when the glucose concentration was alternately shifted between 5.5 mM and 11.1 mM, respectively. However, 22.2 mM glucose profoundly suppressed glucagon secretion. The suppressive effect of high glucose on glucagon release was partially, yet significantly, reversed by the presence of GIP, as glucagon secretion increased from a non-detectable level at 22.2 mM glucose alone to 10,175 ± 145 pg, n = 10 (P < 0.01). The glucagonotropic effect of GIP was dose-dependent in the range of 2 · 10−9–2 · 10−7 M, at 11.1 mM glucose. Our data show that GIP is able to substantially reverse the suppressive effect of a high glucose load on glucagon secretion.
The Politics of River Trade: Tradition and Development in the Upper Plata, 1780–1870

The Politics of River Trade: Tradition and Development in the Upper Plata, 1780-1870. Thomas Whigham. Albuquerque: University of New Mexico Press, 1991. 274 pp. $50.00 (cloth). ISBN 0-8263-1312-4.
Licensed Nurse Staffing and Health Service Availability in Residential Care and Assisted Living

Objectives: To create data-driven typologies of licensed nurse staffing and health services in residential care and assisted living (RC/AL). Design: Cluster analysis was used to describe the patterns of licensed nurse staffing and 47 services and the extent to which these clusters were related. Setting: RC/AL communities in the United States. Participants: A convenience sample of administrators and healthcare supervisors from 89 RC/AL communities in 22 states. Measurement: RC/AL characteristics, licensed nurse staffing (total number of hours that registered nurses (RNs) and licensed practical nurses (LPNs) worked), number of hours that contract nurses worked, and availability of 47 services. Results: Analysis revealed four licensed nurse staffing clusters defined according to total number of hours and the type of nurse providing the hours (RN, LPN, or a mix of both). They ranged from no or minimal RN and LPN hours to high nursing hours with a mix of RNs and LPNs. The 47 services clustered into five clusters: basic services; technically complex services; assessments, wound care, and therapies; testing and specialty services; and gastrostomy and intravenous medications. The availability of services was related to the presence of nurses (RNs and LPNs) except for the gastrostomy and intravenous medication services, which were not readily available. Conclusion: The amount and skill mix of licensed nurse staffing varies in RC/AL and is related to the types of services available. These findings may have implications for resident care and outcomes. Future work in this area, including extension to include nonnurse direct care workers, is needed.
Down-regulation of vitamin D receptor in mammospheres: implications for vitamin D resistance in breast cancer and potential for combination therapy.

Vitamin D signaling in mammary cancer stem cells (MCSCs), which are implicated in the initiation and progression of breast cancer, is poorly understood. In this study, we examined vitamin D signaling in mammospheres which are enriched in MCSCs from established breast cancer cell lines. Breast cancer cells positive for aldehyde dehydrogenase (ALDH+) had increased ability to form mammospheres compared to ALDH− cells. These mammospheres expressed MCSC-specific markers and generated transplantable xenografts in nude mice. Vitamin D receptor (VDR) was significantly down-regulated in mammospheres, as well as in ALDH+ breast cancer cells. TN aggressive human breast tumors as well as transplantable xenografts obtained from SKBR3 expressed significantly lower levels of VDR but higher levels of CD44 expression. Snail was up-regulated in mammospheres isolated from breast cancer cells. Inhibition of VDR expression by siRNA led to a significant change in key EMT-specific transcription factors and increased the ability of these cells to form mammospheres. On the other hand, over-expression of VDR led to a down-regulation of Snail but increased expression of E-cad and significantly compromised the ability of cells to form mammospheres. Mammospheres were relatively insensitive to treatment with 1,25-dihydroxyvitamin D (1,25D), the active form of vitamin D, compared to more differentiated cancer cells grown in presence of serum. Treatment of H-Ras transformed HMLEHRas cells with DETA NONOate, a nitric oxide (NO)-donor led to induction of MAP-kinase phosphatase -1 (MKP-1) and dephosphorylation of ERK1/2 in the mammospheres. Combined treatment of these cells with 1,25D and a low-concentration of DETA NONOate led to a significant decrease in the overall size of mammospheres and reduced tumor volume in nude mice. Our findings therefore, suggest that combination therapy using 1,25D with drugs specifically targeting key survival pathways in MCSCs warrant testing in prospective clinical trial for treatment of aggressive breast cancer.
THE EFFECT OF CRITERION SCORE GROUPING UPON ITEM PARAMETER ESTIMATION

The differential effect of three grouping procedures upon the first two moments of the sampling distributions of the parameters X50 and β of the item characteristic curve were investigated empirically. The results of the study indicated that differences in the variances of β and X50 as well as in the bias of X50 could be attributed to differences in grouping procedures. Item parameter estimates possessing the minimum bias and variance within the study were those yielded by the grouping procedure which used equally spaced criterion score intervals and the same number of subjects within each interval.
Single pediatric center experience with multiple device implantation for complex secundum atrial septal defects.

Objectives: We analyzed the efficacy and complications of placing multiple transcatheter devices to correct complex ASD in a primarily pediatric population. Background: Limited pediatric information exists regarding the safety and efficacy of using multiple devices for secundum atrial septal defects (ASD) when multiple defects are present. Methods: Cath lab, echo, and clinical data were reviewed for 238 patients who underwent device closure of secundum ASD from 2000 to 2007 at a single pediatric center. Of those requiring multiple devices (n = 15), residual shunting and complications were assessed. Results: 238 patients (mean age 12 yrs; 80% 15 yrs, with a median age of 10.8 yrs (range 2–31). There was no compromise or obstruction to surrounding structures, and no device embolization or erosion was noted. A tiny thrombus was observed on the right sided screw of one device with no clinical sequelae. One patient (age 31 yrs) died at home 30 days post procedure from cardiac tamponade. Autopsy revealed the 3 intact devices in stable position without evidence of erosion. Latest available echo follow-up for the group revealed functional resolution of atrial level shunting in all patients. Conclusion: Multiple devices can safely and effectively be implanted in the pediatric population to close complex ASD. © 2008 Wiley-Liss, Inc.
Ultrasonographic ear length measurement in normal second- and third-trimester fetuses

Abstract Objective: We sought to develop a nomogram for fetal ear length measurements from a large population of healthy second- and third-trimester fetuses and to investigate the correlation of fetal ear length with other standard fetal biometry measurements, as follows: biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length. Study Design: Ear length measurement was obtained prospectively in 4240 singleton fetuses between 15 and 40 weeks' gestational age. Either complete data for normal karyotype on amniocentesis or normal infant examination at birth or both were available in 2583 cases. These constituted the final study population. Results: A nomogram was developed by linearly regressing ear length on gestational age (Ear length [in millimeters] = 1.076 × Gestational age [in weeks] – 7.308). There was a high correlation between ear length and gestational age ( r = 0.96; P =.0001). Conclusion: The results of this study provide normative data on growth of fetal ear length from 15 to 40 weeks' gestation. Good correlation was also observed between ear length and other fetal biometric measurements (biparietal diameter, head circumference, abdominal circumference, femur length, and humerus length). (Am J Obstet Gynecol 2000;183:230-4.)
Synthesis, Structural Investigation, and Reactivity of Neutral and Cationic Bis(guanidinato)zirconium(IV) Complexes

The mono(guanidinato) complex Cp(guan)ZrCl2 (1; guan = η2-(iPrN)2C(NMe2)) was prepared by treatment of CpZrCl3 (Cp = η5-C5H5) with the in situ generated lithium guanidinate salt 2. The dimethylamino group of 1 resists quaternization by alkylating and silylating reagents. Complex 1 undergoes ligand redistribution when treated with 2 equiv of MeLi, but reaction with 2 equiv of MeMgCl affords the dimethyl derivative Cp(guan)ZrMe2 (3). Insertion of 2 equiv of diisopropylcarbodiimide into the Zr−N bonds of (Me2N)2ZrCl2(THF)2 produces the bis(guanidinato)zirconium dichloride complex (guan)2ZrCl2 (4). Alkylation of 4 with 2 equiv of MeLi or PhCH2MgCl affords the dialkyl derivatives (guan)2ZrMe2 (5) and (guan)2Zr(CH2Ph)2 (6), respectively. Variable-temperature NMR experiments on 6 reveal a limiting C2-symmetric solution structure at 253 K. Complex 5 undergoes reaction with electrophiles (Me3SiOTf (OTf = OSO2CF3), B(C6F5)3, [Ph3C][B(C6F5)4]) to yield stable products of methide abstraction: neutral complexes (guan...
Endoscopic retrograde cholangiopancreatography in the diagnosis and management of pancreatic diseases

Endoscopic retrograde cholangiopancreatography (ERCP) has been used for diagnosis and treatment of pancreatic diseases for over 20 years. ERCP has been most intensely investigated for acute biliary pancreatitis. Randomized trials have proven that its use will decrease morbidity and have suggested a decrease in mortality for patients with severe gallstone pancreatitis. ERCP is also valuable in detecting and treating main pancreatic duct leaks with transpapillary stenting. Symptomatic pseudocysts, which may be seen in either acute or chronic pancreatitis, can be drained via the papilla or through creation of a cystogastrostomy or cystoduodenostomy with a needle-knife sphincterotome. Endoscopic treatment of patients with recurrent acute pancreatitis presumed due to pancreas divisum and sphincter of Oddi dysfunction remains controversial. Dominant pancreatic strictures or calculi in the setting of chronic pancreatitis may be treated with stenting and removal of calculi to improve abdominal pain. Finally, diagnosis of pancreatic cancer by brush cytology and palliative management of biliary obstruction with various plastic and expandable metal sents have simplified management of this difficult problem.
Fatal cardiovascular collapse following acute colchicine ingestion.

Background: A previously published prognostic rule predicts 100% survival after ingestion of cochicine doses less than 0.5 mg/kg and 100% mortality after ingestion of more than 0.8 mg/kg. This rule inaccurately predicted survival in a recent case. Case Report: We present a case of fatal colchicine poisoning in an adult who ingested a maximum of 39.6 mg of colchicine (0.40 mg/kg). He subsequently developed hypotension which was refractory to fluid resuscitation and infusion of vasopressors. He died of cardiovascular collapse approximately 35 hours after ingestion. Discussion: Fatal outcomes are possible even with colchicine doses less than 0.5 mg/kg. Physicians caring for colchicine-poisoned patients must be prepared for the possibility of acute cardiovascular collapse and ventricular dysrhythmias regardless of the reported dose of colchicine.
Supersymmetric contributions to weak decay correlation coefficients

We study supersymmetric contributions to correlation coefficients that characterize the spectral shape and angular distribution for polarized µ- and beta-decays. In the minimal supersymmetric standard model (MSSM), one-loop box graphs containing superpartners can give rise to non-(V-A)[direct-product](V-A) four-fermion operators in the presence of left-right or flavor mixing between sfermions. We analyze the present phenomenological constraints on such mixing and determine the range of allowed contributions to the weak decay correlation coefficients. We discuss the prospective implications for future µ- and beta-decay experiments, and argue that they may provide unique probes of left-right mixing in the first generation scalar fermion sector.
On the Effective Transfer Impedance of Thin Coaxial Cable Shields

It is shown that the effective transfer impedance per unit length of a thin coaxial cable shield is given by Zs h2/Ys, where ZS and Ys are, respectively, the cable's inductive transfer impedance per unit length and capacitive transfer admittance per unit length, and h is the axial propagation constant. This general result is illustrated by consideration of a specific shield model, the M-filar filamentary helix.
Augmentation of Pulmonary Epithelial Cell IL-8 Expression and Permeability by Pre-B-cell Colony Enhancing Factor

Previous studies in our lab have identified Pre-B-cell colony enhancing factor (PBEF) as a novel biomarker in acute lung injury (ALI). The molecular mechanism of PBEF involvement in the pathogenesis of ALI is still incompletely understood. This study examined the role of PBEF in regulating pulmonary alveolar epithelial cell IL-8 expression and permeability. Human pulmonary alveolar epithelial cells (cell line and primary cells) were transfected with human PBEF cDNA or PBEF siRNA and then cultured in the presence or absence of TNFα. PBEF and IL-8 expression were analyzed by RT-PCR and Western blotting. In addition, changes in pulmonary alveolar epithelial and artery endothelial cell barrier regulation with altered PBEF expression was evaluated by an in vitro cell permeability assay. Our results demonstrated that, in human pulmonary alveolar epithelial cells, the overexpression of PBEF significantly augmented basal and TNFα-stimulated IL-8 secretion by more than 5 to 10-fold and increased cell permeability by >30%; the knockdown of PBEF expression with siRNA significantly inhibited basal and TNFα-stimulated IL-8 secretion by 70% and IL-8 mRNA levels by 74%. Further, the knockdown of PBEF expression also significantly attenuated TNFα-induced cell permeability by 43%. Similar result was observed in human pulmonary artery endothelial cells. These results suggest that PBEF may play a vital role in basal and TNFα-mediated pulmonary inflammation and pulmonary epithelial barrier dysfunction via its regulation of other inflammatory cytokines such as IL-8, which could in part explain the role of PBEF in the susceptibility and pathogenesis of ALI. These results lend further support to the potential of PBEF to serve as a diagnostic and therapeutic target to ALI.
Functional Coverage Driven Test Generation for Validation of Pipelined Processors

Functional verification of microprocessors is one of the most complex and expensive tasks in the current system-on-chip design process. A significant bottleneck in the validation of such systems is the lack of a suitable functional coverage metric. This paper presents a functional coverage based test generation technique for pipelined architectures. The proposed methodology makes three important contributions. First, a general graph-theoretic model is developed that can capture the structure and behavior (instruction-set) of a wide variety of pipelined processors. Second, we propose a functional fault model that is used to define the functional coverage for pipelined architectures. Finally, test generation procedures are presented that accept the graph model of the architecture as input and generate test programs to detect all the faults in the functional fault model. Our experimental results on two pipelined processor models demonstrate that the number of test programs generated by our approach to obtain a fault coverage is an order of magnitude less than those generated by traditional random or constrained-random test generation techniques.
A Week at the Irente Rainbow School

In this chapter, readers are taken through a week in the life of the Irente Rainbow School, following teachers and students through their daily activities from arrival to dismissal. Mornings are predominately spent learning academic lessons, while afternoons are mostly spent in vocational and life-skills classes. The school takes a break for tea in midmorning in accordance with Tanzanian cultural norms, and it serves lunch to all present around noon. Students learn to care for their school and support each other in academic and vocational work. During academic lessons, they learn about math, literacy, and science; during vocational lessons, they learn about gardening, carpentry, visiting, cleaning, and sports. They study art, music, and games every week.
Learning Style and Adjustment Issues of International Students

Abstract Instructors can help international students to be successful at U.S. universities by determining, then explaining to them, their preferred learning styles. Such knowledge can assist college professors in adjusting their teaching styles to the students' learning styles. In this study, the authors examined the learning styles of international students enrolled in an MBA program. Although 80% of the students had learned by the lecture method in their home countries, the results of the Canfield Learning Styles Inventory (Canfield, 1992) indicated that they preferred to learn by direct experience.
A macroepigenetic approach to identify factors responsible for the autism epidemic in the United States

The number of children ages 6 to 21 in the United States receiving special education services under the autism disability category increased 91% between 2005 to 2010 while the number of children receiving special education services overall declined by 5%. The demand for special education services continues to rise in disability categories associated with pervasive developmental disorders. Neurodevelopment can be adversely impacted when gene expression is altered by dietary transcription factors, such as zinc insufficiency or deficiency, or by exposure to toxic substances found in our environment, such as mercury or organophosphate pesticides. Gene expression patterns differ geographically between populations and within populations. Gene variants of paraoxonase-1 are associated with autism in North America, but not in Italy, indicating regional specificity in gene-environment interactions. In the current review, we utilize a novel macroepigenetic approach to compare variations in diet and toxic substance exposure between these two geographical populations to determine the likely factors responsible for the autism epidemic in the United States.