cssi/SciSciGPT-SciSciNet huggingface dataset:
The synoptic climatology of polar-low outbreaks over the Gulf of Alaska and the Bering Sea

The synoptic environments conducive to the development of polar-low outbreaks are investigated for the North Pacific region, including the Gulf of Alaska and the Bering Sea. Two case studies of polar low outbreaks are presented, using standard synoptic data, all available ship reports and satellite imagery. One case occurred over the Bering Sea, and the other over the Gulf of Alaska. The case studies show that the environments conducive to the development of strong polar lows include: a deep outflow of arctic air over open water and a cold-core, closed low aloft. Additionally, forcing from a small-scale vortex aloft is associated with the formation of strong polar lows. When synoptic conditions are favorable for the formation of polar lows, a series of them often develop in close proximity to each other. Furthermore, once favorable environmental conditions have developed, they often persist for several days and can result in several polar-low outbreaks. To develop a climatology of the synoptic environments conducive to the formation of polar lows over the Gulf of Alaska, 500 mb height, temperature, 1000–500 mb thickness and surface pressure data were composited for days when mature polar lows were present. The composite studies reveal the presence of significant negative anomalies centered over the northern Gulf of Alaska in the 500 mb temperature, height and thickness fields. These results indicate the presence of enhanced positive vorticity and the potential for deep convection over the area. The evolution of the negative-height anomaly indicates the development of a trough that results in a northerly component of the flow aloft over the Aleutian Islands and Alaska Peninsula as much as three days prior to the outbreak of polar lows. Strong northerly surface flow across open water indicated by the surface pressure composite results in small static stabilities at low levels and in the development of baroclinicity in the boundary layer through the modifying effects of surface fluxes of sensible and latent heat. Finally, a comparison is made between the climatology of polar lows over the Gulf of Alaska and over the Norwegian and Barents Seas. DOI: 10.1111/j.1600-0870.1987.tb00310.x
The role of microvilli in the agglutination of cells by concanavalin A

Abstract Morphological correlates of lectin agglutinability were examined in eight cell lines of varying sensitivity to agglutination by concanavalin A (ConA). The number of microvilli on the surface of cells growing in monolayers was positively correlated with agglutinability. However, when cells were brought into suspension, they all developed numerous microvilli which persisted when the cells were treated with ConA regardless of whether or not they were agglutinated by the lectin. Treatment of cells with dibutyryl cyclic AMP (db-cAMP) and theophylline caused a parallel decrease in agglutinability and numbers of microvilli in monolayer cultures, but suspended cells from control and treated cultures were identical in appearance in the absence or presence of ConA. The surface morphology of cells agglutinated by ConA was very similar to that of cells that spontaneously agglutinated in the absence of the lectin, and surface bound ConA was rapidly withdrawn from microvilli on all cell types. Neither the morphology of cells nor the surface distribution of ConA can explain observed differences in agglutinability.
Neural network based transient stability assessment of electric power systems

Abstract In this paper a systematic procedure to design an intelligent neurocontroller to assess the dynamic security of interconnected power systems is presented. This approach focuses on the integration of modern control theory together with the adaptive networks to determine critical clearing time for power systems.
Role of Myosin Light Chain Phosphorylation in the Regulation of Cytokinesis

Phosphorylation of regulatory light chain (RMLC) of myosin II at Ser19/Thr18 is likely to play important roles in controlling the morphological changes seen during cell division of cultured mammalian cells. Phosphorylation of RMLC regulates the activity of myosin II, an essntial motor for cytokinesis, and phosphorylation of RMLC shows dramatic changes during mitosis. Two exzymes, myosin phosphatase and kinase, control phosphorvlation of RMLC. Myosin phosphatase is activated during mitosis, apparently as a result of mitosis-specific phosphorylation of the myosin phosphatase targeting subunit (MYPT). This activation of myosin phosphatase is likely to result in RMLC dephosphorylation, causing the disassemly of stress fibers and focal adhesions during prophase. The phosphorylation of MYPT is lost in cyotokinesis, which would decrease myosin phosphatase activity. At the same time, ROCK (Rho-kinase) probably phosphorylates MYPT at its inhibitory sites, further decreasing the activity of myosin phosphatase. These changes in MYPT phosphorylation would raise RMLC phosphorylation, leading to the activation of myosin II for cyotokinesis. RMLC phosphorylation is also regulated by several RMLC kinases including ROCK (Rho-kinase), MLCK and citron kinase, all of which are localized at cleavage furrows. Future studies should examine whether these multiple kinases are redundant or whether they control distinct aspects of cell division.
Highly localized surface oxide thickening on polycrystalline silicon thin films during cyclic loading in humid environments

Abstract Previous studies on very high-cycle fatigue behavior of thin silicon (Si) films suggest a strong environmental dependence of the degradation mechanism, the precise nature of which is still the subject of debate. This is partly due to contradictory evidence on the presence of thick post-cycling surface oxides. In the present study, 2 μm thick polycrystalline Si structures subjected to fully reversed stresses at 40 kHz are used to investigate fatigue degradation in a harsh environment (80 °C, 90% relative humidity). Transmission electron microscopy (TEM) on vertical through-thickness slices reveals highly localized thick oxides (∼50 nm) in the area of large cyclic stress, but not in control specimens. Such localized oxides are likely to be missed with horizontal TEM slices, as done in previous studies. This study highlights the challenges in characterizing nanometer-scale phenomena with micron-scale specimens, and confirms the viability of the reaction-layer fatigue mechanism for the high-cycle/very high-cycle fatigue behavior of micron-scale silicon.
Serious Overestimation in Quantitative PCR by Circular (Supercoiled) Plasmid Standard: Microalgal pcna as the Model Gene

Quantitative real-time PCR (qPCR) has become a gold standard for the quantification of nucleic acids and microorganism abundances, in which plasmid DNA carrying the target genes are most commonly used as the standard. A recent study showed that supercoiled circular confirmation of DNA appeared to suppress PCR amplification. However, to what extent to which different structural types of DNA (circular versus linear) used as the standard may affect the quantification accuracy has not been evaluated. In this study, we quantitatively compared qPCR accuracies based on circular plasmid (mostly in supercoiled form) and linear DNA standards (linearized plasmid DNA or PCR amplicons), using proliferating cell nuclear gene (pcna), the ubiquitous eukaryotic gene, in five marine microalgae as a model gene. We observed that PCR using circular plasmids as template gave 2.65-4.38 more of the threshold cycle number than did equimolar linear standards. While the documented genome sequence of the diatom Thalassiosira pseudonana shows a single copy of pcna, qPCR using the circular plasmid as standard yielded an estimate of 7.77 copies of pcna per genome whereas that using the linear standard gave 1.02 copies per genome. We conclude that circular plasmid DNA is unsuitable as a standard, and linear DNA should be used instead, in absolute qPCR. The serious overestimation by the circular plasmid standard is likely due to the undetected lower efficiency of its amplification in the early stage of PCR when the supercoiled plasmid is the dominant template.
Natural Convection in Shallow Enclosures With Differentially Heated Endwalls

We consider a low-aspect-ratio two-dimensional rectangular cavity, differentially heated with an arbitrarily large horizontal temperature difference. Steady-state results obtained from numerical solutions of the transient Navier--Stokes equations are given for air using the ideal gas law and Sutherland law transport properties. We clarify the different flow regimes possible by using numerical results for aspect ratios 0.025less than or equal toAless than or equal to1 and for Rayleigh numbers (based on height) 10/sup 2/less than or equal toRaless than or equal to10/sup 9/. We present Nusselt numbers, and temperature and velocity distributions, and compare them with existing data. At high Ra in the Boussinesq limit we show the existence of weak secondary and tertiary flows in the core of the cavity. In addition we present novel solutions in the non-Boussinesq regime. We find that the classical parallel flow solution, accurate in the core of the cavity in the Boussinesq limit, does not exist when variable properties are introduced. For higher Rayleigh numbers, we generalized the well-known analytical boundary layer solution of Gill. The non-Boussinesq solutions show greatly reduced static pressure levels and lower critical Rayleigh numbers.
Seedling establishment in a masting desert shrub parallels the pattern for forest trees

The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in intact stands vs. small-scale disturbances at four contrasting sites for nine growing seasons following emergence after a mast year. The primary cause of first-year mortality was post-emergence cache excavation and seedling predation, with contrasting impacts at sites with different heteromyid rodent seed predators. Long-term establishment patterns were strongly affected by rodent activity in the weeks following emergence. Survivorship curves generally showed decreased mortality risk with age but differed among sites even after the first year. There were no detectable effects of inter-annual precipitation variability or site climatic differences on survival. Intraspecific competition from conspecific adults had strong impacts on survival and growth, both of which were higher on small-scale disturbances, but similar in openings and under shrub crowns in intact stands. This suggests that adult plants preempted soil resources in the interspaces. Aside from effects on seedling predation, there was little evidence for facilitation or interference beneath adult plant crowns. Plants in intact stands were still small and clearly juvenile after nine years, showing that blackbrush forms cohorts of suppressed plants similar to the seedling banks of closed forests. Seedling banks function in the absence of a persistent seed bank in replacement after adult plant death (gap formation), which is temporally uncoupled from masting and associated recruitment events. This study demonstrates that the seedling establishment syndrome associated with masting has evolved in desert shrublands as well as in forests.
Predictors of Success In a Dietetic Internship/Master of Science Degree Program

Abstract Of individuals who applied to a Combined Dietetic Internship (DI)/Masters degree (MS) program between 1988 and 1992, approximately 1/3 (64) participated in the study. Thirty-seven of these applicants attended the program. Data consisted of scores derived from applicant files, a short questionnaire, and grade point averages (GPA) of subjects who attended the program. The predictor variables included every item on a rating form used by a student selection committee. Due to the large number of predictor variables, Principle Factor Analysis was used to group related variables, decreasing the number of variables to be entered into Stepwise Logistic Regression. The four factors identified were Graduate Record Exam-Analytical scores (GRE-A), GRE-Verbal scores (GRE-V), GPA, and Reason for Application. Using Stepwise Logistic Regression, none of the four factors were significantly correlated (p> .05) with the completion of the MS degree. Using the data of subjects who attended the program, the four factors were entered into Correlation Analysis. Two factors were significantly correlated, GRE-A Factor with GPA after the Internship (r =0.33, p=.046) and the MS degree (r=0.61, p=.003) and GRE-V Factor with GPA after MS degree (r=0.45, p=.04). The GPA and Reason factors did not significantly correlate (p>.05) with any of the variables. Current selection criteria may not accurately predict whether an applicant will complete a MS degree program. However, GRE analytical and verbal scores are important criteria since significant correlations were observed between GRE-A with GPA after the DI and MS, and GRE-V with GPA after the MS.
Some evidences of spin-optical phonon relaxation

Abstract The exponential terms in the measured relaxation rates of Sm3+ in LaEs, Er3+ in LaEs and Yb3+ in YbEs have been identified as arising from the spin-optical phonon relaxation process.
Negative-Ion formation in the explosives RDX, PETN, and TNT by using the reversal electron attachment detection technique.

First results of a beam-beam, single-collision study of negative-ion mass spectra produced by attachment of zero-energy electrons to the molecules of the explosives RDX, PETN, and TNT are presented. The technique used is reversal electron attachment detection (READ) wherein the zero-energy electrons are produced by focusing an intense electron beam into a shaped electrostatic field which reverses the trajectory of electrons. The target beam is introduced at the reversal point, and attachment occurs because the electrons have essentially zero longitudinal and radial velocity. The READ technique is used to obtain the “signature” of molecular ion formation and/or fragmentation for each explosive. Present data are compared with results from atmospheric-pressure ionization and negative-ion chemical ionization methods.
Dynamics and equilibrium for the formation of fluorescent Lewis acid-base exciplexes and triplexes between 9-aminophenanthrene and aliphatic amines

The excited singlet states of 9-aminophenanthrene and its N-aminoalkyl derivatives are strongly fluorescent in cyclohexane. Addition of low concentrations of Et3N, Pr2NH, or PrNH2 results in a red shift of the emission maximum and moderately decreased fluorescence intensity. Analysis of the fluorescence behavior using a combination of singular value decomposition with self-modeling and kinetic analysis provides evidence for the sequential formation of 1 ∶ 1 (exciplex) and 1 ∶ 2 (triplex) complexes between the excited 9-aminophenanthrene and ground-state alkylamine, both of which are strongly fluorescent. Both the formation and decay of the exciplex and triplex are dependent upon the extent of amine N-alkylation. Rate constants and equilibrium constants for complex formation follow the order 1° ∼ 2° > 3°, analogous to that for the formation of ground-state complexes between amines and the soft Lewis base HgBr2. Similarly, N-aminoalkyl derivatives of 9-aminophenanthrene form intramolecular exciplexes. Excited-state complex formation is attributed to a Lewis acid–base interaction between the excited aminophenanthrene (lone-pair acceptor) and ground-state amine (lone-pair donor). The factors which determine the stability of excited-state Lewis acid–base complexes are characteristic of the specific excited-state acceptor. No universal scale of lone-pair donor strength can be expected to describe the formation of such complexes.
Neurogenic Detrusor Overactivity Is Associated with Decreased Expression and Function of the Large Conductance Voltage- and Ca2+-Activated K+ Channels

Patients suffering from a variety of neurological diseases such as spinal cord injury, Parkinson’s disease, and multiple sclerosis often develop neurogenic detrusor overactivity (NDO), which currently lacks a universally effective therapy. Here, we tested the hypothesis that NDO is associated with changes in detrusor smooth muscle (DSM) large conductance Ca2+-activated K+ (BK) channel expression and function. DSM tissue samples from 33 patients were obtained during open bladder surgeries. NDO patients were clinically characterized preoperatively with pressure-flow urodynamics demonstrating detrusor overactivity, in the setting of a clinically relevant neurological condition. Control patients did not have overactive bladder and did not have a clinically relevant neurological disease. We conducted quantitative polymerase chain reactions (qPCR), perforated patch-clamp electrophysiology on freshly-isolated DSM cells, and functional studies on DSM contractility. qPCR experiments revealed that DSM samples from NDO patients showed decreased BK channel mRNA expression in comparison to controls. Patch-clamp experiments demonstrated reduced whole cell and transient BK currents (TBKCs) in freshly-isolated DSM cells from NDO patients. Functional studies on DSM contractility showed that spontaneous phasic contractions had a decreased sensitivity to iberiotoxin, a selective BK channel inhibitor, in DSM strips isolated from NDO patients. These results reveal the novel finding that NDO is associated with decreased DSM BK channel expression and function leading to increased DSM excitability and contractility. BK channel openers or BK channel gene transfer could be an alternative strategy to control NDO. Future clinical trials are needed to evaluate the value of BK channel opening drugs or gene therapies for NDO treatment and to identify any possible adverse effects.
Exploring the limits to sustainable energy consumption for organisms and devices

Energy consumption accounts for a significant portion of a product's environmental impacts. Biological research suggests the existence of a fundamental energetic limit. After reviewing research into the influence of thermodynamic and economic principles on living systems' evolution, a biological principle explaining the existence of a mass-specific energy consumption rate limit for living systems is identified and quantified. These findings lead to a potential sustainable engineering principle and metric. Simple assessments of consumer goods and vehicles illustrate the principle's application. Discussions of this biologically inspired limit and the general value of seeking environmental design guidance from living systems close this paper.
Soliton-breather approach to classical sine-Gordon thermodynamics.

Thermodynamics of the Boltzmann gas consisting of solitons, antisolitons, and breathers of the classical sine-Gordon system is studied by taking their interactions into account. A compact expression for the thermodynamic potential is obtained, which agrees with that obtained from the classical limit of the Bethe-ansatz formulation of the quantum sine-Gordon thermodynamics. We further find that the average number of breathers excited at low temperatures (m\ensuremath{\ll}T\ensuremath{\ll}M, where m and M are the phonon and the soliton masses, respectively) is half the total number of degrees of freedom of the system.
A model for detecting early metabolic changes in neonatal asphyxia by 1H-MRS.

In newborn rabbits, the early cerebral metabolic changes caused by hypoxic-ischemic (H-I) insult was examined by using volume localized 1H-MRS (STEAM). Partial ischemia was caused by unilateral carotid artery ligation, and hypoxia was induced by 10% oxygen inspiration for 150 minutes. Lactate immediately increased after hypoxia induction and almost disappeared 120 to 150 minutes after removal of hypoxia in both H-I and hypoxia-only experiments. Lactate production correlated well with decrease of the blood oxygen saturation. More lactate was produced on ischemic side 50 minutes post-hypoxia induction in H-I study. Ischemia alone did not cause any significant lactate production. Lactate caused by hypoxia can be dynamically monitored by localized 1H-MRS. Existence of regional ischemia can induce greater anaerobic glycolysis and may affect the pattern of brain injury under hypoxia. 1H-MRS is a sensitive tool to detect the acute metabolic changes caused by H-I insult.
Advances in Attenuation Correction Techniques in PET

Molecular imaging using PET has evolved from a vigorous academic field into the clinical arena. Considerable advances have been made in the design of high-resolution standalone PET and combined PET/CT units dedicated to clinical whole-body scanning. Likewise, much worthwhile research focused on the development of quantitative imaging protocols incorporating accurate data correction techniques and sophisticated image reconstruction algorithms. Since its inception, photon attenuation in biological tissues has been identified as the most important physical degrading factor affecting PET image quality and quantitative accuracy. Various strategies have been devised to determine an accurate attenuation map to enable correction for nonlinear photon attenuation in whole-body PET studies. This article presents the physical and methodological basis of photon attenuation and summarizes state-of-the-art developments in algorithms used to derive the attenuation map aiming at accurate attenuation compensation of PET data. Future prospects, research trends, and challenges are identified, and directions for future research are discussed.
Mini-implant anchorage for the orthodontic practitioner

Mini-implant-enhanced anchorage has become a popular concept in orthodontics over the past years. Although these systems are routinely used in university settings, there is some reservation because of lack of information in private practices. This article will introduce the concept of mini-implant anchorage to the orthodontic practitioner.
Elevated transforming growth factor beta levels in the plasma of cytokine-treated cancer patients and normal allogeneic stem cell donors

Background: Allogeneic blood stem-cell donors demonstrate more vigorous mobilization of CD34 + cells to the circulation in response to cytokine administration than do autologous donors. Transforming growth factor (TGF- &#103 1) has been implicated as a mobilization inhibitor. A study was designed to determine whether plasma TGF- &#103 1 levels are elevated in cytokine-mobilized autologous cancer donors compared with cytokine-mobilized normal donors. Methods: Plasma collected from 29 autologous cancer donors and 33 normal allogeneic stem-cell donors following administration of mobilizing cytokines just prior to the first collection was assayed for TGF- &#103 1 using a sandwich-type ELISA. Plasma from three volunteers not treated with cytokine was also analyzed. Comparisons were made using the Student's t test on log-transformed data. Results: Average TGF- &#103 1 levels in the plasma of cancer patients were significantly higher than in allogeneic stem-cell donors (4.4 ng/mL versus 7.2 ng/mL; p = 0.038). Th...
AN IMPROVED ELECTRONIC DEW-POINT HYGROMETER

Abstract After a theoretical discussion of the basic physical principles involved in the dew-point method of hygrometry, which serves to establish the inherent advantages of the technique, the paper describes the operating principles and the design of an improved, automatic, electronic dew-point hygrometer for laboratory or field use. The instrument makes use of photoelectric detection of condensation on a cooled, polished metal mirror combined with a radio-frequency induction heating system and an all-electronic proportional heat-control servo system. The instrument makes possible the continuous and automatic measurement of atmospheric water-vapor under all conditions of temperature with nearly constant accuracy and small lag.
H2O grain size and the amount of dust in Mars' Residual north polar cap

In Mars' north polar cap, the probable composition of material residual from the annual condensation cycle is a mixture of fine dust and H2O grains of comparable size and abundance. However, metamorphism of such material will gradually lower its albedo by increasing the size of the H2O grains only. If the cap is undergoing net annual sublimation (as inferred from water vapor observations), late summer observations should be of old ice with H2O grain sizes of 100 microns or more. Ice of this granularity containing 30 percent fine dust has a reflectivity similar to that of dust alone; the observed albedo and computed ice grain size imply dust concentrations of 1 part per 1000 or less. The brightness of the icy areas conflicts with what would be expected for a residual cap deposited by an annual cycle similar to that observed by Viking and aged for thousands of years. The residual cap surface cannot be 'old dirty' ice. It could be old, coarse, and clean; or it could be young, fine, and dirty. This brings into question both the source of the late summer water vapor and the formation rate of laminated terrain.
Microstructures from a directionally solidified NiAl-Cr eutectic deformed at room temperature

Directionally solidified alloys based on the NiAl-Cr eutectic have shown promise as high temperature structural materials. This eutectic is characterized by a fibrous microstructure consisting of chromium rods embedded within a NiAl matrix. The reinforcing metal phase provides improvements in the elevated temperature strength and the room temperature fracture toughness of the NiAl matrix. The fracture toughness of the NiAl-Cr eutectic is much greater than that of NiAl. The directionally solidified NiAl-Cr eutectic has a fracture toughness of approximately 18--21 MPa[radical]m while polycrystalline NiAl has a fracture toughness of 6 MPa[radical]m. Single crystals of NiAl oriented with a [001] notch plane have a fracture toughness of 8 MPa[radical]m. Recently, the fracture resistance of fibrous NiAl-refractory metal eutectics has been described by crack trapping and crack bridging mechanisms. However, mechanical property data for NiAl-Cr eutectic are sparse, especially those generated at room temperature. Typically, the fracture behavior is characterized by scanning electron microscopy (SEM) and optical microscopy. To complement these existing data, observations of the deformation and fracture behavior by transmission electron microscopy (TEM) are reported here.
Evaluating the relationship between ecological and habitat conditions using hierarchical models

Understanding the relationship between an index of biological community state and habitat is important for policy makers and environmental managers. A common approach to modeling this relationship is to use regression. However, this simple method becomes complicated when the data are clustered and have both within-cluster and between-cluster spatial correlation. This article proposes a Bayesian hierarchical model that incorporates both types of spatial correlation. This model yields both an understanding of the within-cluster relationships as well as an overall relationship between these variables. We apply this method to evaluate the relationship between the index of biotic integrity (a common measure of fish condition) and the qualitative habitat evaluation index (a common measure of habitat quality). This method allows us to show that there is a relationship between the biological community state and habitat and that this relationship varies across river basins, while accounting for the within- and between-spatial correlations.
Improved outcomes with early vocal fold medialization for vocal fold paralysis after thoracic surgery

Objective: To determine the clinical impact of early versus late surgical therapy for new onset unilateral vocal cord paralysis (UVCP) after thoracic surgery. Study design: Patients diagnosed with new onset UVCP after esophagectomy, pneumonectomy or pulmonary lobectomy were reviewed to determine the incidence of pneumonia, need for postoperative bronchoscopy and length of stay (LOS). Comparisons were made between patients undergoing early (≤4 days after thoracic procedure) versus late rehabilitation (≥5 days after thoracic procedure) of their UVCP with vocal cord medialization. Results: Some 86 patients (27 esophagectomies, 43 pneumonectomies and 16 lobectomies) with new onset UVCP were examined. A total of 32 patients (37.2%) underwent early vocal cord medialization and 54 (62.8%) underwent late repair. The pneumonia rate for patients undergoing early vocal cord medialization (6.3%) was significantly lower than the rate for vocal cord medialization (37.0%, P=0.001, χ2). Early medialization patients required fewer postoperative bronchoscopies (mean number of bronchoscopies, 0.26) than late medialization patients (mean bronchoscopies, 0.94, P=0.013). The median LOS was significantly decreased for early versus late medialization patients in both pneumonectomy (reduction in LOS of 8 days) and lobectomy groups (reduction in LOS of 7 days). Conclusions: Early vocal cord medialization decreases the pneumonia rate, the requirement for postoperative bronchoscopies and the LOS for patients suffering from new onset UVCP after thoracic surgery. Significance: Consideration should be given to early medialization for new onset UVCP when medically sound.
Language barriers to health care in the United States.

49.6 million Americans speak a language other than English at home. Yet many patients who need medical interpreters have no access to them. Dr. Glenn Flores writes that language barriers can have deleterious effects.
A TECHNIQUE FOR HYPOPHYSECTOMY OF THE RAT

The hypophysectomized rat has become of great value as a test animal in studies of the pituitary gland and its relations to the other organs of internal secretion. To be of greatest usefulness, a large number of these animals is desirable. However, in our attempts to product a colony of hypophysectomized animals the available descriptions proved inadequate, and it was found necessary to modify the various techniques in order to develop an operation which was simple and rapid, and yet which totally removed the gland. The need for large numbers of these test animals seems to justify the following detailed account of the procedure, which aims to remove the anterior and posterior lobes of the hypophysis, leaving the pars tuberalis, the pituitary stalk, and the diaphragma sellae intact. Phillip E. Smith (4), in 1930, described a parapharyngeal approach for hypophysectomy of the rat, and in the same year Richter and Wislocki (3) suggested improvements in the method. Recently Koyama (2) has published an ingeniou...
Resist Technology For Submicrometer Optical Lithography

This paper reviews the impact of advances in photoresists and processing on submicrometer imaging using optical lithography. Among the topics discussed for the extension of single-layer resists into the submicrometer regime are the use of dyes, the development of materials for the deep-UV region, image reversal, and contrast-enhancement layers. Approaches to dealing with substrate topographical effects, such as multilayer resists and antireflection coatings, are reviewed. Future directions to extend optical lithography further and address current problems are discussed.
Renal hemodynamic effects of lovastatin in a renal ablation model.

Abstract Objectives Patients with renal mass reduction of more than 50% are at increased risk for progressive renal failure. Lipid-lowering agents have been shown to preserve renal function in various models of chronic renal failure. This study was performed to evaluate the hemodynamic effects of lovastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, in the remnant kidney model. Methods Two groups of animals were studied. Group 1 (n = 9) served as controls and group 2 (n = 14) received lovastatin, 15 mg/kg/day orally, for 2 weeks after renal ablation. Glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, ultrasonic flow probe), and 24-hour protein excretion were measured in anesthetized rats. Results Two weeks after renal ablation, GFR was 0.28 ± 0.09 mL/min/gkw (gram kidney weight) in group 1, whereas in group 2, lovastatin preserved GFR at 0.58 ± 0.3 mL/min/gkw ( P P P Conclusions Lovastatin preserves renal function in a renal ablation model after 2 weeks of treatment. It specifically increased total RBF. Therefore, in addition to its known cholesterol lowering effect, lovastatin also has the direct renal hemodynamic effect of increasing RBF and maintaining GFR.
Tropical Cyclone Intensification from Asymmetric Convection: Energetics and Efficiency

Abstract Prior studies of the linear response to asymmetric heating of a balanced vortex showed that the resulting intensity change could be very closely approximated by computing the purely symmetric response to the azimuthally averaged heating. The symmetric response to the purely asymmetric part of the heating was found to have a very small and most often negative impact on the intensity of the vortex. This result stands in contrast to many previous studies that used asymmetric vorticity perturbations, which suggested that purely asymmetric forcing could lead to vortex intensification. The issue is revisited with an improved model and some new methods of analysis. The model equations have been changed to be more consistent with the anelastic approximation, but valid for a radially varying reference state. Expressions for kinetic and available potential energies are presented for both asymmetric and symmetric motions, and these are used to quantify the flow of energy from localized, asymmetric heat sour...
Liver fat has a stronger association with risk factors for type 2 diabetes in African-American compared with Hispanic adolescents.

Context: Although overweight and obese African-Americans (AAs) have less visceral adipose tissue (VAT) and liver fat (LF) than Hispanics, they have a similar risk for type 2 diabetes. Objective: We examined ethnic differences in the association between VAT and LF with risk factors for type 2 diabetes to help explain this paradox. Design: We conducted a cross-sectional study in an academic pediatric care facility. Subjects: Subjects were overweight and obese AA (n = 131; 15.5 ± 3.3 years old) and Hispanic adolescents (n = 227; 14.7 ± 3.0 years old). Main Outcome Measures: Outcome measures included insulin sensitivity (SI), acute insulin response (AIR), and disposition index (DI) by frequently sampled iv glucose tolerance test and minimal modeling. Results: LF, not VAT, was inversely associated with SI, and the effect of high LF compared with low was more pronounced in AAs (Pinteraction < .05). In Hispanics, high LF was associated with a 24% lower SI (P < .01) and a 31% increase in AIR (P < .01) and was not...
Analysis of a method and a system to determine heat transfer and properties of fluids in the absence of temperature measurements and a modified Fourier Equation

The technique to determine by capacitance measurements heat transfer, thermal transport and dielectric properties of fluids introduced recently is now analyzed for a simple system of spherical geometry. The temperature distribution under programmed heat input to a fluid annulus between solid walls is computed by finite difference method for the determination of the capacitance time function of the arrangement. A system of heavy wall structure and heated long enough will produce a capacitance-time curve which is a function of thermal conductivity only. Thermal diffusivity is of influence in thin wall systems. The capacitance change of a heavy wall arrangement is related to the thermal conductivity of the test fluid by a modified Fourier equation. This equation describes the heat flow through the fluid layer but includes the thermal expansion of the solid walls. The change of geometry with Δ T is therefore accounted for. For other multicomposite structures the Fourier equation must be further modified by including the thermal expansion of all materials of the structure and possibly also their compressibilities.
238 RIBOFLAVIN INFLUENCE ON HEPATIC AND BRAIN RESPONSES TO TRYPTOPHAN IN NEONATAL GERBILS

Tryptophan (T) photooxidized in the presence of riboflavin (R) alters hepatic function in developing animals. Solutions of T (48 um/ml) were either exposed to (+L) or protected from (-L) light for 12 hours (in the presence, +R, or absence, -R, of 1 mg/ dl of R). Two-week old suckling gerbils were randomly assigned to daily intraperitoneal injections of T+R+L, T+R-L, T+L, T-L or were untreated for 7 d (4 mM/kg−1d−1 of T). Animals were killed on day 8 and assessed for: serum γ-glutamyl transferase; serum, liver and brain T conc; body, brain & liver weight. Data (X±SD): γ-GT activity and brain T conc were significantly increased in the presence of R and either +L or -L. Serum and liver concentrations of T were similar amongst the treatment regimens. Liver T was greater in the treated animals than in those untreated. Our data suggest the role of R in the alteration of hepatic function; further, both R and L alter brain conc of T in the developing gerbil. The clinical implications of the infusion of amino acids in the presence of R and L must be considered.
Recursive Path Models When Both Predictor and Response Variables are Categorical

Recursive path analysis is a useful tool for inference on a sequence of three or more response variables in which the causal effects of variables, if any, are in one direction. The primary objective in such analysis is to decompose the total effect of each variable into its direct and indirect components. Methods for recursive analysis of a chain of continuous variables are well developed but there is a lack of uniform methodology when the variables are categorical. In this paper we propose an approach for categorical response variables that is based on generalized linear models. The proposed method has the flexibility of allowing the use of common categorical data models such as the Poisson, Probit and logistic regression models, along with definitions of direct and indirect effects in terms of relative risks and odds ratios. The method can be implemented easily using standard statistical software such as the GENMOD procedure of SAS. This proposed method is illustrated using real data.
Using petrophysics and cross-section balancing to interpret complex structure in a limited-quality 3-D seismic image

A study was done to characterize deep, prolific Ellenburger gas reservoirs at Lockridge, Waha, West Waha, and Worsham‐Bayer fields in Pecos, Ward, and Reeves counties in West Texas. A major effort of the study was to interpret a 176-mi2 3-D seismic data volume that spanned these fields. Well control defined the depth of the Ellenburger, the principal interpretation target, to be 17 000–21 000 ft (5200–6400 m) over the image area. Ellenburger reflection signals were weak because of these great target depths. Additionally, the top of the Ellenburger had a gentle, ramp‐like increase in acoustic impedance that did not produce a robust reflection event. A further negative influence on seismic data quality was the fact that a large portion of the 3-D seismic area was covered by a variable surface layer of low‐velocity Tertiary fill that was, in turn, underlain by a varying thickness of high‐velocity salt/anhydrite. These complicated near‐surface conditions attenuated seismic reflection signals and made static c...
Income and price elasticities of demand at low levels of real income

Abstract For levels of real per capita income starting at 3% of the U.S. per capita income in 1975, income and price elasticities of demand are tabulated. The prominent role of food consumption for low-income households is emphasized.
Emotion-Provoking Personalization of News: Informing Citizens and Closing the Knowledge Gap?

Emotion is often treated as unconducive to rationality and informed citizenship. For this reason, journalistic styles that personalize issues and elicit emotion are typically not taken seriously as information sources. The experimental study reported here tested these sentiments through the knowledge gap hypothesis. Eight investigative news stories, arguably important to informed citizenship (e.g., child labor, corruption in public housing administration, lethality of legal drugs), were each presented in two versions. One featured emotional testimony of ordinary people who experienced the issue, and the other did not—resembling the traditional view of news as cold hard facts. Emotional versions were associated with smaller knowledge gaps between higher and lower education groups. Moreover, the size of knowledge gaps varied across three memory measures: free recall, cued recall, and recognition. Contrary to the inimical role that is traditionally assigned to emotion, these findings suggest a facilitative r...
Dietary glycine and threonine interactive effects in broilers

Abstract Little information is available regarding the interaction of dietary Thr and Gly on the potential metabolic sparing effects, live production, or breast meat yield of broilers. To test these potential interactions, 432 one-day-old Ross 308 male broilers were fed a common diet up to 21 d of age, and then fed 1 of 6 experimental diets. A factorial arrangement of treatments consisted of 3 dietary levels of standardized digestible Thr (0.57, 0.61, and 0.65%) in combination with 2 levels of total Gly + Ser (1.55 and 1.65%). Experimental diets were fed from 21 to 42 d of age, with live performance, carcass traits, and free blood plasma levels of Gly, Ser, and Thr serving as evaluation criteria. Interactions (P ≤ 0.05) were observed for BW gain, feed consumption, carcass and breast meat weight, and carcass yield, all showing improvements with increasing dietary Thr in combination with low dietary Gly + Ser treatments. Circulating plasma Gly, Ser, and Thr were affected by their respective dietary status.
Free-hand ultrasound scanning approaches for volume quantification of the mouse heart left ventricle

Two approaches for free-hand motion tracking that enable volumetric quantification of the murine heart were investigated. One approach used an instrumented, multijointed articulated arm attached to a 14 MHz ultrasound transducer array. A second approach used an E-beam transducer - a modified linear transducer array containing a main imaging array adjacent to three perpendicular tracking arrays. Motion between successive B-mode image frames was computed by tracking image speckle in each tracking array. Both tracking systems produced accurate results in a phantom validation study (4.50% error and 3.75% error for estimates derived using the articulated arm and E-beam tracking techniques, respectively). The tracking approaches also were tested in vivo on three mice. Results were compared to values obtained by mounting each mouse on a micromanipulator, adjusting its position by 0-5-mm increments, and acquiring B-mode images using a high-resolution ultrasound scanner. Left ventricular end diastolic volume (LVEDV) estimates differed from values obtained using the high-resolution scanner by a mean error of 18.2% and 2.60% for eight scans conducted on each of two mice using the articulated arm, and a mean error of 13.6%, 6.53%, and 12.58% for eight scans conducted on each of three mice using the E-beam
Structural patterns in the corpora pedunculata of orthoptera: A reduced silver analysis

The calyx region and pedunculus of the corpora pedunculata (“mushroom bodies”) were studied comparatively in reduced silver preparations of the brain from 16 species of Orthoptera representing four families (Acrididae, Gryllidae, Tettigoniidae, and Gryllacrididae). In the acridid grasshopper Melanoplus femurrubrum (de Geer), on which emphasis was placed, the concave primary calyx is bilayered and exhibits a special central zone. Globuli cell axons occur within both layers. The bulbous accessory calyx is unlayered and sends anterior extensions beneath the primary calyx. The main input tracts into primary and accessory calyx, respectively, are the tractus olfactorio-globularis and tritocerebral tract. The pedunculus consists of one barrel with three major fiber columns, of which two originate in the primary calyx and one in the accessory calyx. Its fibers display a coaxial arrangement, superimposed on the tripartite organization. Structural conditions in other acridids are similar. In the other families the calyx region similarly includes a bilayered primary calyx and unlayered accessory calyx. The latter, variable in form, is closely associated with the base of the primary calyx in tettigoniids and gryllacridids. The calyces receive the same major tracts as in acridids. The pedunculus is coaxially organized. These features are theorized to have originated as follows. In the progenitors of Orthoptera the corpora pedunculata included two mutually equivalent, bilayered calyces and a “double-barreled” pedunculus. The orthopteran primary calyx arose through coalescence of these calyces. Concomitantly, the two peduncular barrels fused into one. The accessory calyx originated at the base of the primary calyx, from the class of globuli cell axons of the latter's external layer. Probably this occurred in response to increased functional importance of tritocerebral input.
Coupling between microstrip lines with finite width ground plane embedded in polyimide layers for 3D-MMICs on Si

Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimeter-wave integrated circuits on CMOS (low resistivity) Si wafers. Thin film microstrip lines (TFMS) with finite width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS lines are susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and experimental measurements are used to show that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions.
A 3-D Magnetic Charge Finite-Element Model of an Electrodynamic Wheel

When a magnetic rotor is both rotated and translationally moved above a conductive, nonmagnetic, guideway eddy currents are induced that can simultaneously create lift, thrust, and lateral forces. In order to model these forces, a 3D finite-element model with a magnetic charge boundary has been created. The modeling of the rotational motion of magnets by using a fictitious complex magnetic charge boundary enables fast and accurate steady-state techniques to be used. The conductive regions have been modeled using the magnetic vector potential and nonconducting with the magnetic scalar potential. The steady-state model has been validated by comparing it with a Magsoft Flux 3D transient model (without translational velocity) and with experimental results. The 3D model is also compared with a previously presented 2D steady-state complex current sheet model.