cssi/SciSciGPT-SciSciNet huggingface dataset:
Cell spreading as a hydrodynamic process

Many cell types have the ability to move themselves by crawling on extra-cellular matrices. Although cell motility is governed by actin and myosin filament assembly, the pattern of the movement follows the physical properties of the network ensemble average. The first step of motility, cell spreading on matrix substrates, involves a transition from round cells in suspension to polarized cells on substrates. Here we show that the spreading dynamics on 2D surfaces can be described as a hydrodynamic process. In particular, we show that the transition from isotropic spreading at early time to anisotropic spreading is reminiscent of the fingering instability observed in many spreading fluids. During cell spreading, the main driving force is the polymerization of actin filaments that push the membrane forward. From the equilibrium between the membrane force and the cytoskeleton, we derive a first order expression of the polymerization stress that reproduces the observed behavior. Our model also allows an interpretation of the effects of pharmacological agents altering the polymerization of actin. In particular we describe the influence of Cytochalasin D on the nucleation of the fingering instability.
Interference effects in reticon photodiode array detectors.

A detector system incorporating the Reticon RL1024S photodiode array has been constructed at the National Oceanic and Atmospheric Administration Aeronomy Laboratory as part of a double spectrograph to be used to study the Earth’s atmosphere from ground-based and aircraft-based platforms. To determine accurately the abundances of atmospheric trace gases, this new system must be able to measure spectral absorptions as small as 0.02%. The detector, manufactured by EG&G Reticon, exhibits superior signal-to-noise characteristics at the light levels characteristic of scattered skylights, but interference in the passivating layer (a thin layer of SiO2 that is deposited during the manufacture to protect the silicon active area from water vapor) causes major problems in achieving the required precision. The mechanism of the problems and the solution we have implemented are described in detail.
Curricular Progress Assessments: The MileMarker

A challenge in pharmacy education is to document student learning and retention. With the unveiling of the Standards 2007 by the Accreditation Council for Pharmacy Education, the impetus has been placed on colleges and schools of pharmacy that must meet those standards. One possible response to this challenge is administering progress examinations to assess a student's knowledge base at specified points in the curriculum. The University of Houston College of Pharmacy has developed an annual comprehensive assessment to evaluate student learning and retention at each level of the didactic portion of the curriculum. The development, utilization, and results of MileMarker Assessments are described.
Small bowel obstruction secondary to incomplete removal of a ventriculoperitoneal shunt: case report.

Small bowel obstruction and partial enteral loss secondary to entrapment by an incompletely removed ventriculoperitoneal shunt is a previously unreported hazard. (Neurosurgery 26:526-528, 1990)
Differences between Dialysis Modality Selection and Initiation

Background Although dialysis modality education is associated with higher rates of peritoneal dialysis (PD) use, some patients start hemodialysis (HD) therapy despite initially selecting PD as their modality of choice. This study seeks to identify predictors of this discrepancy. Study Design Retrospective cohort study. Setting & Participants 217 patients who received dialysis modality education at the University of Rochester between January 2004 and September 2009 and subsequently started dialysis therapy. Predictors Demographic (age, race, sex, and timing of education), social (education, income, insurance, marital, employment, and smoking status), and clinical data (estimated glomerular filtration rate, cause of end-stage renal disease [ESRD], number of comorbid conditions, and number of nephrology visits). Outcome HD use at initiation and day 91 of dialysis therapy in patients initially selecting PD. Results Of 217 patients receiving education and starting dialysis therapy, at the time of education, 124 chose PD, 52 were undecided, and 41 chose HD. Modality distribution at the time of dialysis therapy initiation was 150 with HD and 67 with PD. Of 124 patients who chose PD at the time of education, 59 started dialysis therapy with PD and 65 started with HD. On day 91, a total of 60 patients were on PD therapy and 55 were on HD therapy. Nine patients had either died, undergone transplant, or not yet reached 91 days of dialysis therapy. On multivariable analysis, nonglomerular cause of ESRD, age older than 75 years, and not being employed predicted starting with HD therapy, whereas age older than 75 years, nonwhite race, and nonglomerular cause of ESRD predicted HD use at day 91. Limitations Single-center observational study. Conclusions This study shows that patients choosing PD after dialysis education may not start with this modality and identifies several predictors of this mismatch. Further investigation into predictors of this discrepancy and strategies promoting a PD start in patients selecting this modality are warranted.
MRI myocardial tagging.

MRI myocardial tagging is now a well-developed method for evaluation of regional myocardial contraction. A series of progressively more refined imaging strategies, combined with advances in analytic strategies have provided a strong armamentarium of methods. Important insights into normal human physiology of left ventricular systolic and diastolic function have been developed using one-dimensional, two-dimensional and three-dimensional analyses of myocardial deformation. In disease states, improved understanding and detection of early alterations in myocardial function in hypertensive heart disease has been possible. In addition, improved understanding of effects of ischemia and infarction on regional function has been possible. Further, after acute myocardial infarction, clearer definition of the natural history of contractile dysfunction in the infarct region and the zone adjacent to the infarct have been possible. Similarly, effects on regional function of a number of important pharmacologic agents used for treatment, such as angiotensin converting enzyme inhibitors, beta blockers and angiotensin receptor blockers have been characterized. In the cardiomyopathies, myocardial tagging has permitted more reliable assessment of heterogeneity of segmental function, especially in hypertrophic cardiomyopathy. Finally, initial applications of myocardial tagging to assessment of right ventricular regional function in hypertrophied hearts with and without major congenital abnormalities have generated advances in understanding of effects of hypertrophy on right ventricular function.J. Magn. Reson. Imaging 1999;10:609–616. © 1999 Wiley-Liss, Inc.
WAIS subtest score distributions of institutionalized retardates.

WAIS subtest scores for three samples of institutionalized retardates, from the East Coast (n = 509), West Coast (n = 436), and Midwest (n = 113) were compared. The Midwest sample norms diverged most from the remaining two sets, but the most significant finding was the heterogeneity of the intrarest variance, suggesting the influence of exogenous factors related to the institutional setting.
Estimation of the Long Term Correlation Coefficients by Simulation

This paper proposes a simulation method for obtaining the estimate of the long term correlation coefficients between different low-frequency wave-induced loads acting on a ship hull. They are essential part of the load combination procedures in design and strength evaluations. Existing theory is limited to linear time-invariant systems with weakly stationary stochastic inputs such as waves during a single sea state (short-term). The simulation treats the non-stationary wave elevations during the ship’s entire life (long-term) as a sequence of different stationary Gaussian stochastic processes. Different sea states (HS , T0 , Wave Direction) are sampled, using rejection sampling, from the joint probability density functions fitted to every Marsden zone on the ship’s route. The time series of the loads are simulated from the load spectra for each sea state, including the effects of loading condition, heading, speed, seasonality and voluntary as well as involuntary speed reduction. The estimates of the correlation coefficients are then calculated from these time series. The simulation time can be significantly reduced (to the order of seconds rather than hours and days) by introducing the seasonal variations into a single voyage. It is proven that the estimate of the correlation coefficient, obtained by simulating only a single voyage, approaches the true correlation coefficient in probability as the number of simulated load values increases. The simulation method can also be used for finding the long-term exceedance probabilities of the peak values of individual loads as well as for analyzing various load combinations (linear and nonlinear). Related concepts and limitations of this method are demonstrated by an example of a containership operating between Boston, MA and Southampton, UK.Copyright © 2010 by ASME
Separating the Knowledge Layers: Cognitive Analysis of Search Knowledge Through Hierarchical Goal Decompositions

Hierarchical goal decompositions have proved to be a useful method to make explicit the knowledge required by users to perform tasks in a wide range of applications such as computer-aided drafting (CAD) systems. This analysis method progressively decomposes a given task starting from the task layer on the top of the decomposition, to the keystroke layer at the bottom. The analysis enables a close inspection of the knowledge required to perform the task at each layer of the decomposition. In this paper we show how the method of hierarchical goal decomposition can be used to understand more precisely the knowledge that is required to perform information search tasks. The analysis pinpoints: (1) the critical strategies in the intermediate layers of knowledge that are known by experts searchers; (2) why such knowledge is difficult to acquire by novice searchers; (3) how the analysis provides testable predictions of behavior based on the acquisition of different types of knowledge. We conclude by discussing the advantages provided by hierarchical goal decompositions, and how such an approach can lead to the design of systems and training.
Fear and Safety Engage Competing Patterns of Theta-Gamma Coupling in the Basolateral Amygdala

Theta oscillations synchronize the basolateral amygdala (BLA) with the hippocampus (HPC) and medial prefrontal cortex (mPFC) during fear expression. The role of gamma-frequency oscillations in the BLA is less well characterized. We examined gamma- and theta-frequency activity in recordings of neural activity from the BLA-HPC-mPFC circuit during fear conditioning, extinction, and exposure to an open field. In the BLA, slow (40-70 Hz) and fast (70-120 Hz) gamma oscillations were coupled to distinct phases of the theta cycle and reflected synchronous high-frequency unit activity. During periods of fear, BLA theta-fast gamma coupling was enhanced, while fast gamma power was suppressed. Periods of relative safety were associated with enhanced BLA fast gamma power, mPFC-to-BLA directionality, and strong coupling of BLA gamma to mPFC theta. These findings suggest that switches between states of fear and safety are mediated by changes in BLA gamma coupling to competitive theta frequency inputs.
Severe Idiopathic Constipation Is Associated With a Distinctive Abnormality of the Colonic Myenteric Plexus

We analyzed the clinical, radiographic, esophageal manometric, and pathologic features of 26 women with severe, idiopathic constipation. Twenty-four patients were between 19 and 39 yr of age. Stool frequency was once every 5–28 days. On barium enema examination, 9 of 24 patients had colons of increased length and 4 of these 9 patients had colons of increased width (>10 cm). Radionuclide solidmeal gastric-emptying studies were normal in 23 patients tested. Esophageal manometry demonstrated high-amplitude waves in 10 of 22 patients and long-duration waves in 3 of these 10 patients. Rectal biopsy specimens showed normal submucosal neurons in all patients and melanosis coli in 6. Twelve patients underwent subtotal colectomies for constipation. Conventional light microscopy using hematoxylin and eosin serial sections showed (a) melanosis coli in 4 patients; (b) normal smooth muscle in 11; (c) thinning of the circular muscle in 1; and (d) no apparent abnormalities of the myenteric plexus in any. In contrast, silver stains of the myenteric plexus showed (a) quantitatively reduced numbers of argyrophilic neurons in 10 patients; (b) morphologically abnormal argyrophilic neurons in 11; (c) decreased numbers of axons in 11; and (d) increased numbers of variably sized nuclei within ganglia in all 12. A coded analysis of the silver stains of colons from 8 patients with constipation and 19 control cases demonstrated that the pathologic abnormalities of severe idiopathic constipation could be differentiated from controls. Thus, severe idiopathic constipation is associated with a pathologically identifiable abnormality of the myenteric plexus. This abnormality appears different from anything previously described in intestinal pseudoobstruction.
Study on Mathematical Model of Cylindricality Error

According to the standard definition of cylindricality error, set up any space surface cylindricality errors of least squares mathematics model. The coordinate origin of the model can be freely selected, nor equal angle interval among discrete sampling points. Analysis by computer simulation, results show that the model developed is right and pratical. On the basis of mathematical models, using four direct algorithm for unconstrained optimization, cylindricality errors can be evaluated in accordance with the minimum conditions. Mathematical models can be used for three-coordinate measuring machine and also available for other intelligent instrument for measuring parts of the cylindricality errors.
Suggested Intense Positron Source based on (micropole) undulator induced pair production

Abstract The construction of an Intense Positron Source (IPS) is suggested. The intensity of the produced positrons is to exceed that of any other existing source by orders of magnitude. The instantaneous intensity is to be 10 3 to 10 6 times higher yet. Fast positrons are to be produced in pulses of time duration ≈ 1 ns to 10 ps. Slow positron pulses of order ≲ 100 ps are expected. The phase space density of positrons at production will be in excess of what can be achieved by other methods. The IPS is to consist of 1) an undulator (usually a micropole undulator, i.e. an undulator with submillimeter period) in which gamma rays in the MeV range will be generated by electron beams circulating in a storage ring; 2) a heavy metal target, in which e + e − pairs will be produced by the generated gamma rays; 3) moderators to thermalize the produced positrons; and 4) a transport system through which the slow positrons will move. Spinoff benefits provided by the suggested device include the following: The equipment may be used to create (or destroy) nuclear isotopes in a controlled manner (i.e. without producing unwanted species); to produce (or destroy) in a controlled way chemical elements; to produce well collimated intense photon beams in the multi 100 MeV range for nuclear physics research, with intensities many orders of magnitude higher than can be achieved today; to generate intense bursts of neutrons; to supply fast positrons produced at high intensities (10 16 to 10 17 s −1 ) and within a small transverse phase space, to future high energy colliders, thereby perhaps even eliminating the need for damping rings.
Uptake and metabolism of [3H]norepinephrine in the cerebral hemispheres of chick embryos.

— The uptake and metabolism of [3H]norepinephrine were studied in slices of cerebral hemispheres removed from chick embryos at 10, 15 and 20 days of embryonic age, as well as from 90-day-old hens. Brain tissue from all age groups concentrated [3H]norepinephrine to much greater levels at 37°C than at 0°C. There was a marked increase in the rate of accumulation of [3H]norepinephrine in tissues from 10 to 15 days of embryonic age, with no further increase in the rate observed from 15 to 20 days of embryonic age. Tissue slices were incubated for 20 min with [3H]norepinephrine, and the deaminated metabolites of norepinephrine were separated by paper chromatography. In tissues from all age groups, the neutral metabolites were produced in greater amounts than the acid metabolites. A significant increase in the amounts of deaminated metabolites formed was observed in the period from 10 to 15 days of embryonic age and a significant decrease in the amounts formed was observed in the period from 15 to 20 days of embryonic age. The deamination at 20 days was very similar to that observed in the adult. A significant decrease in the level of the deaminated metabolites was noted in all age groups in response to cocaine (an inhibitor of neuronal uptake mechanisms), an observation suggesting that mechanisms for neuronal uptake of NE are functional by 10 days of embryonic development in the chick. However, a significant increase in the level of deaminated metabolites in response to reserpine (an inhibitor of uptake of NE into storage granules) was observed only in slices taken from 20-day embryos and from the 90-day-old hen. The effect in the hen was more prominent than in the 20-day embryo. These results were interpreted to indicate that mechanisms for the uptake of NE develop at an earlier embryonic age than mechanisms for the storage of NE and that mechanisms for storage continue to develop after hatching.
The effect of pressure on the formation of alkali metal borate ion pairs at 25°C

Pressure dependent UV-visible spectrophotometric measurements were used to determine\(\Delta \bar V^ * \) and\(\Delta \bar \kappa ^ * \) for the formation of alkali metal borate ion pairs. The association constant for each ion pair was measured at 25°C and at ionic strengths of 0.1 and 1.0m over a pressure range of 1 to 2000 atm. The pressure dependence of the apparent association constants, KA(P)/KA(1), have been fitted to $$[RT/(P - 1)]ln[K_A (P)]/[K_A (1)] = - \Delta \bar V^0 + \Delta \bar \kappa ^0 [(P - 1)/2]$$ to determine\(\Delta \bar V^0 and \Delta \bar \kappa ^0 \). The\(\Delta \bar V^0 \) for the alkali metal borate ion pairs range from 5–9 cm3-mol−1. The association constants were also measured as a function of ionic strength at 1 atm. Extrapolation to I=0 yielded KA of 2.12, 0.66, 0.76 and 1.12 for [LiB(OH)4], [KB(OH)4], [RbB(OH)4] and [CsB(OH)4], respectively. The trend generally indicates less ion pairing and a smaller volume change for the ion pair formation as the size of the cation increases. The concept of localized hydrolysis is used to explain the trend observed in the equilibrium constant of the ion pair as the cation size is changed.
A TEST OF SCHILLING'S INTERFIRM PRODUCT MODULARITY MODEL: THE BICYCLE DRIVETRAIN INDUSTRY 1980-1990.

We empirically test an existing theoretical model of interfirm product modularity (Schilling, 2000) with an unusual case of de-modularization of a dominant design in a mature industry. We find that...
A Calibrated Hot-Box Approach for Steady-State Heat-Transfer Measurements in Air Duct Systems

A procedure for measurement of steady-state heat transfer through the walls of air duct systems under actual operating conditions and configuration is described. The procedure uses two independent measurement techniques. A calibrated hot box is the primary measurement technique and an airstream temperature-drop measurement provides a secondary technique. The calibrated hot box is a heavily insulated box which is sealed around a duct conveying cold air. A temperature controller and electric resistance heaters maintain the box temperature as close as possible to ambient temperature. Thus, the laboratory space acts as a guard for the box. The energy input to the box is measured with a wall-hour meter. The total energy input, corrected for the heat transfer through the box wall, represents the heat transfer through the test system. The temperature-drop technique uses thermocouples to measure the temperature difference between two stations in the test duct and orifice plates to measure airflow. The heat transfer from this technique is compared with calibrated hot-box measurements. An automatic data collection system is used so that tests can be conducted over a long period of time to assure steady-state conditions and to determine reproducibility. Verification of the calibrated hot-box technique is achieved by testingmore » a specially constructed section of duct whose heat transfer can be readily calculated. Experimental and calculated data are presented for this duct system.« less
Flagella-independent surface motility in Salmonella enterica serovar Typhimurium

Flagella are multiprotein complexes necessary for swimming and swarming motility. In Salmonella enterica serovar Typhimurium, flagella-mediated motility is repressed by the PhoP/PhoQ regulatory system. We now report that Salmonella can move on 0.3% agarose media in a flagella-independent manner when experiencing the PhoP/PhoQ-inducing signal low Mg2+. This motility requires the PhoP-activated mgtA, mgtC, and pagM genes, which specify a Mg2+ transporter, an inhibitor of Salmonella’s own F1Fo ATPase, and a small protein of unknown function, respectively. The MgtA and MgtC proteins are necessary for pagM expression because pagM mRNA levels were lower in mgtA and mgtC mutants than in wild-type Salmonella, and also because pagM expression from a heterologous promoter rescued motility in mgtA and mgtC mutants. PagM promotes group motility by a surface protein(s), as a pagM-expressing strain conferred motility upon a pagM null mutant, and proteinase K treatment eliminated motility. The pagM gene is rarely found outside subspecies I of S. enterica and often present in nonfunctional allelic forms in organisms lacking the identified motility. Deletion of the pagM gene reduced bacterial replication on 0.3% agarose low Mg2+ media but not in low Mg2+ liquid media. Our findings define a form of motility that allows Salmonella to scavenge nutrients and to escape toxic compounds in low Mg2+ semisolid environments.
Specific and non specific immunologic reactivity of regional lymph node lymphocytes in human malignancy

The in vitro blastogenic responses of lymphocytes from peripheral blood leukocytes (PBL) and lymph-node leukocytes (LNL) of cancer patients were examined simultaneously in paired studies. The lymph nodes were obtained at the time of surgical tumor extirpation from the area draining or adjacent to the tumor, but were determined to be tumor-free. There was an inverse relationship between the responses of PBL and LNL to tumor cells (TC). In those subjects where the PBL responses to TC were positive (stimulation index >3), the responses of LNL were usually negative and significantly lower. In those subjects where the LNL responses to TC were positive, the PBL responses were usually negative and significantly lower. A positive response by LNL to TC correlated with a significantly higher mixed lymphocyte culture response among LNL than among PBL. There was no correlation of these responses to TC with the PBL or LNL responses to phytohemagglutinin. There was a trend for the PBL response to TC to be higher than that of the LNL in patients with gastrointestinal cancer and melanoma and lower than that of LNL in patients with breast and squamous cell carcinoma. Stage of disease and age also influenced these results.
Effects of Sulphate, Iron and Hydrogen on the Microbiological Conversion of Acetic Acid to Methane*

Sulphate stimulated the rate of conversion of acetic acid to methane in enriched cultures as well as in liquid from anaerobic fermenters fed with wastes, but the effect depended on the soluble iron content of the culture. At low soluble iron contents, i.e. 0–02–0–05 mM, sulphate had little or no immediate (after 7–10 d) effect, but at 0–5 mM or higher soluble iron content, sulphate (0–6 mM or more) significantly increased the rate of acetic acid conversion over that obtained with 0–5 mM soluble iron without sulphate. Long-term continuous culture tests (100–160 d) showed that 0–6 mM or more sulphate increased the maximum growth rate of the culture from 0–07–0–08 d without sulphate to 0–14–0–16/d, even at iron levels of 0–02–0–05 mM. Hydrogen was inhibitory to the conversion of acetic acid to methane under all conditions tested, but stimulated the reduction of sulphate when present.
The in vitro effects of clonidine and dexmedetomidine on human myometrium.

Background: α 2 -adrenergic agonists have been used extensively in the field of anaesthesia. Their direct effect on the human myometrium was investigated in this in vitro study, as this may have clinical repercussions in obstetric anaesthesia. Method: Strips of pregnant human myometrium obtained from six individuals at elective caesarean section were mounted on the Mulvany myograph in Krebs solution to which increasing concentrations of clonidine and dexmedetomidine (1×10 −11 to 1×10 −6 g/mL) were added. Results: Dexmedetomidine increased uterine contractility at simulated clinical plasma concentrations (1×10 −9 g/mL). These effects were seen with clonidine only at much higher tissue bath concentrations (1×10 −7 g/mL). Conclusion: The effect of dexmedetomidine on human myometrium has profound implications in obstetric anaesthesia and needs further clinical investigation.
DEVELOPMENTS ON AN UNSTEADY BOUNDARY-LAYER ANALYSIS: INTERNAL AND EXTERNAL FLOWS

Abstract A boundary-layer solution procedure for two-dimensional, compressible unsteady flows has been developed for non-Cartesian generalized grids consistent with first-order boundary-layer theory. The scheme is applicable to both internal and external unsteady flows. Example results demonstrate advantages of using a non-Cartesian grid for external flows. Boundary-layer solutions were reported for the first time for a number of flows that had been computed only by quite different approaches, including the numerical solutions to the Navier-Stokes equations. The results computed for several test cases were found to be in good agreement with data available in the literature.
Synergy in lipofection by cationic lipid mixtures: Superior activity at the gel-liquid crystalline phase transition

Some mixtures of two cationic lipids including phospholipid compounds (O-ethylphosphatidylcholines) as well as common, commercially available cationic lipids, such as dimethylammonium bromides and trimethylammonium propanes, deliver therapeutic DNA considerably more efficiently than do the separate molecules. In an effort to rationalize this widespread "mixture synergism", we examined the phase behavior of the cationic lipid mixtures and constructed their binary phase diagrams. Among a group of more than 50 formulations, the compositions with maximum delivery activity resided unambiguously in the solid-liquid crystalline two-phase region at physiological temperature. Thus, the transfection efficacy of formulations exhibiting solid-liquid crystalline phase coexistence is more than 5 times higher than that of formulations in the gel (solid) phase and over twice that of liquid crystalline formulations; phase coexistence occurring at physiological temperature thus appears to contribute significantly to mixture synergism. This relationship between delivery activity and physical property can be rationalized on the basis of the known consequences of lipid-phase transitions, namely, the accumulation of defects and increased disorder at solid-liquid crystalline phase boundaries. Packing defects at the borders of coexisting solid and liquid crystalline domains, as well as large local density fluctuations, could be responsible for the enhanced fusogenicity of mixtures. This study leads to the important conclusion that manipulating the composition of the lipid carriers so that their phase transition takes place at physiological temperature can enhance their delivery efficacy.
Relative Heterothallism and Production of Hybrid Perithecia by Auxotrophic Mutants of Glomerella cingulata from Apple

Glomerella cmgulata is a homothallic species but produces a ridge of fertile perithecia at a frontier between certain wild-type strains on agar. To account for the presence or absence of perithecia earlier workers suggested that alleles at A and B loci control the formation of perithecia at mycelial frontiers in + and – strains. We propose that G. cingulata actually demonstrates “relative heterothallism”. Of 7 induced nutritionally deficient mutants (auxotrophs) in 2 wild-type strains from apple, only one methionine (met-1) and one arginine (arg) mutant in only one wild-type strain gave a heavy ridge of perithecia at their junctures. Neither the met-l nor arg mutations have been identified as those in the A or B locus. The perithecia were either homozygous (selfs) for met-1 or arg, or heterozygous (hybrids). Paired met-1 and arg segregants from hybrid perirhecia as well as diauxotrophic strains from met-l or arg mutants also gave hybrids of selfs. Specific nutritional deficiencies in certain wild-type strains which can direct sexuality are not yet known. Genetic studies are now feasible in G. cingulata to define enzymatic factors responsible for pathogenicity.
Intracranial estradiol benzoate implants and lordosis behavior of ovariectomized guinea pigs.

Abstract Adult ovariectomized Hartley guinea pigs were bilaterally implanted in the ventromedial-arcuate area, caudal anterior hypothalamus, basal anterior hypothalamic-preoptic area or midbrain with stainless steel cannulae with removable inserts. At 0 h, the animals received inserts containing crystalline estradiol benzoate or cholesterol followed 36 h later by a systemic injection of 0.6 mg progesterone. Estradiol benzoate implants in the ventromedial-arcuate area facilitated estrous behavior in 79% of animals. Median characteristics of estrous behavior, classified as ‘good-excellent’, shown by these animals were latency after progesterone injection= 3h and duration= 6h. Implants of estradiol benzoate in the basal anterior hypothalamic-preoptic area resulted in display of estrous behavior in 89% of animals. The behavior shown by these animals was categorized as ‘good’ and latency= 6h and duration= 6h. Implants of estradiol benzoate in caudal anterior hypothalamus (nucleus supra-opticus diffusus) resulted in heat in 50% of animals. Heat was classified as ‘poor’ in these animals and latency= 6h and duration= 4.5h. Maximum lordosis did not vary according to brain region and was about 6 sec for all animals facilitated by intracranial estradiol benzoate. No animals displayed estrous behavior after receiving midbrain implants of estradiol benzoate. None of the cholesterol implanted animals displayed heat. The data are consistent with the concept that there are discrete estradiol-sensitive areas in the basal hypothalamus and basal anterior hypothalamic-preoptic area with a region of relatively poor sensitivity in between.
Vanadium(I) Chloride and Lithium Vanadium(I) Dihydride as Selective Epimetallating Reagents for π- and σ-Bonded Organic Substrates†‡

Subvalent vanadium(I) salts, of empirical formulas, VCl, vanadium(I) chloride and LiVH2, lithium vanadium(I) dihydride, whose efficient preparation, structural constitution and mode of reaction toward certain organic substrates have been described in a preceding article, are here evaluated in their reactions toward a wide variety of π- and σ-bonded organic substrates, namely carbonyl, imine, azo, alkene, 1,3-diene, nitrile π-bonds and C–X, C–O, C–N and N–N σ-bonds. Compared with the high reactivity of CrCl and LiCrH2 reagents in attacking both types of bonds, the VCl and LiVH2 reagents were much milder and selective in epimetallating π-bonds, often forming the 1:1 adduct of LiVH2 and π-bonded substrate as the major product. Finally, the vanadium reagents showed little tendency to cleave C–O, C–S and C–N bonds and a smaller scope in cleaving C–X bonds than their chromium counterparts. Because of their selectivity these vanadium reagents offer the following preparative promise: 1) smooth McMurry carbonyl coupling to their reductive dimers; 2) deoxygenation of epoxides; 3) selective aromatic C–X reduction; 4) high yields of epimetallated carbonyls or imines as intermediates to -hydroxy and -amino acids; 5) 1,4-reductions of 1,3-alkadienes; 6) reductive dimerization of nitriles to ketones; 7) 1,4 or 1,n-epimetallations leading to acyloins or indoles; and 8) reductive dimerizations of azines to produce unusual imidazole derivatives. In explaining the greater kinetic stability of the 1:1 LiVH2 adduct with carbonyl or imine substrates it is pointed out that such epimetallated adducts from LiVH2 would likely be diamagnetic, whereas such adducts from LiCrH2 have an unpaired electron on the Cr center and hence would rupture, so that the electron would be on the C center.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Negotiating cultural differences in urban science education: an overview of teacher’s first-hand experience reflection of cogen journey

Classrooms across the United States increasingly find immigrant science teachers paired with urban minority students, but few of these teachers are prepared for the challenges such cultural assimilation presents. This is particularly true in secondary science education. Identifying potential prospects for culturally adaptive pedagogy in science education is important for students and teachers alike because it provides means for increasing marginalized students’ access to science fields. In this autoethnography, I document my experience as an immigrant science teacher in an urban intermediate school in New York City. Although I possessed the content knowledge highly valued by the current neoliberal agenda, I lacked the cultural adaptivity necessary to foster a successful learning environment. I utilized cogenerative dialogue (cogen) as a tool to ameliorate instances of cultural misalignments and improve teaching and learning in my classroom. The results of the study show that the interstitial culture produced through the implementation of the different forms of cogen became a reference point to draw upon in improving the overall learning environment.
Notes on neotropical Vaccinieae (Ericaceae). VIII. New species of Cavendishia from northwestern South America

Recent field collecting in northwestern South America has resulted in the discovery of numerous new Ericaceae. Twelve new species ofCavendishia are herein described. Line drawings and SEM micrographs are included to illustrate certain taxonomically important features.
Microstructure of ambient and supercritical water. Direct comparison between simulation and neutron scattering experiments

Molecular dynamics simulations of SPC, SPC/E, TIP4P, and ST2 water models are performed at ambient and two supercritical conditions make a direct comparison with recent microstructural data obtained by neutron diffraction with isotopic substitution (NDIS) experiments. The models generally fail to accurately predict details of the NDIS results at supercritical conditions, even though they are somewhat successful at ambient conditions. The failure is not as pronounced as that expected by Postorino et al. because of an unusual density dependence in the structure predicted by two of the models. We also evaluate a model for supercritical water denoted SPCG, a modification of the SPC and SPC/E models, in which the dipole moment is reduced to the bare dipole moment of water. For this model, the predicted structure at supercritical conditions is in much better agreement with experiment. A geometric definition of hydrogen bonding is used to gain insight into the angular dependence of the H...O pair distribution function g{sub OH}(r,{omega}). The simulation results for the five models indicate a strong orientational dependence for the g{sub OH}(r,{omega}) along the H-bonding orientations, with an approximately constant relative strength from ambient to supercritical conditions, suggesting that the angle-averaged radial distribution function, g{sub OH}(r), andmore » its volume integral over the first solvation shell, n{sub OH}(r), may not in themselves be good measures of the strength of the H-bonding. 46 refs., 15 figs., 2 tabs.« less
Some applications of attribute prediction theory to psychophysics

The following development is a coordination of certain aspects of mental test methods and psychophysics. The biserial and triserial prediction equations of the Katzell-Cureton theory are utilized to reformulate the determination of absolute and differential limens from data produced by the constant method.
Distributed control agents approach to energy management in electric shipboard power system

The automatic reconfiguration of electric shipboard power systems is an important step toward improved fight-through and self-healing capabilities of naval warships. The improvements are envisioned by redesigning the electric power system and its controls. This paper presents a new scheme for an energy management system in the form of distributed control agents. The control agents' task is to ensure supply of the various load demands while taking into consideration system constraints and load priorities. A graph theoretic self-stabilizing maximum flow algorithm for the implementation of the agents' strategies has been developed to find a global solution using local information and a minimum amount of communication. A case study using the distributed agents within a multilayer system architecture to function as energy management system is presented.
Dansylation of Unactivated Alcohols for Improved Mass Spectral Sensitivity and Application to Analysis of Cytochrome P450 Oxidation Products in Tissue Extracts

Chemical derivatization is useful for improving the ionization characteristics of poorly or nonionizable analytes in liquid chromatography−mass spectrometry (LC-MS). Dansyl chloride has been widely used as a derivatizing reagent for fluorescence detection and for facilitating the MS detection of phenols and amines, but not for general alcohols. A new dansylation method for improving the mass spectral sensitivity of unactivated alcohols was developed. The dansylated derivative was formed after incubation of the test compound cholesterol and excess dansyl chloride in CH2Cl2 in the presence of 4-(dimethylamino)-pyridine (DMAP) plus N,N-diisopropylethylamine at 65 °C for 1 h, with an overall yield of 96%. The versatility of dansylation was investigated by utilizing representative lipid compounds (containing different numbers of hydroxy groups) for dansylation. All dansylated derivatives of the selected compounds were detected by LC-MS/MS in the electrospray ionization (ESI) positive ion mode. Validation of th...
Engineering the Assembly Pathway of the Baculovirus‐Insect Cell Expression Systema

The synthesis of complex biological structures such as antibodies using recombinant DNA technology is a major biotechnological advance. Active murine antibody (IgG) oligomers, composed of two heavy (H) and two light (L) polypeptide chains, have been expressed and secreted by the baculovirus-insect cell expression system. Unfortunately, expression of the functional antibodies is accompanied by the formation of abnormal protein complexes and aggregates in which the polypeptide chains are bound together into incorrect associations. The formation of these abnormal complexes or protein aggregates in insect cells may be caused by insufficient intracellular levels of two catalytic proteins, immunoglobulin binding protein (BiP or GRP78), and protein disulfide isomerase (PDI). Consequently, we obtained the genes coding for murine BiP and PDI and cloned the genes into the baculovirus vector (Autographa californica nuclear polyhedrosis virus) to obtain AcBB-BiP and AcBB-PDI. Infection of Spodoptera frugiperda (Sf-9) insect cells with these two baculoviruses yielded recombinant proteins of the correct size that were recognized by antibodies to these proteins. Cloning these genes into the baculovirus vector is one approach to engineering the assembly pathway in order to lower aggregation and increase production of functionally active proteins and oligomers.
Roentgen Manifestations of Pulmonary Blastoma

Pulmonary blastomas manifest as well-demarcated lesions with occasional lobulation and cavitation. These lesions vary in size and are generally found in the periphery of the lung. The tumors pathologically contain malignant glands within a comparatively less malignant stroma and are differentiated from carcinosarcomas. Nineteen previous examples have been reported, and the case history of the twentieth follows.
Abortion attitudes and discrepant behaviour: some theoretical issues

Three broad conceptions of attitude formation and structure: conditioning and reinforcement; incentives and conflict : and cognitive consistency; are the basis for an examination of our attitudes toward induced abortion. The discrepancy between stated attitudes toward abortion and observed behaviour is viewed from the perspective of the same three theoretical positions. Also discussed are the variations of abortion decision-making and post-abortal sequelae pre dicted by the three theories. The theoretical issues, and implications from them, are discussed throughout the paper at both the individual and the societal level.
Application of Slow Space Charge Waves on an IREB to Collective Ion Acceleration

Single shot time resolved techniques have been developed and applied to the measurement of the phase velocity, frequency, and coherence of space charge waves on an IREB. We report results for the time evolution of the wave phase velocity as a function of the beam and wave parameters. The application of slow space charge waves to collective ion acceleration will be summarized and a description presented of an experiment to demonstrate the viability of the use of space charge waves for ion acceleration.
Cobalt tris(mercaptoimidazolyl)borate complexes: synthetic studies and the structure of the first cobaltaboratrane

The paramagnetic complexes (TmtBu)CoX (X = Cl, Br, I) have been readily prepared and structurally characterized and provide a convenient entry into cobalt(II) tris(mercaptoimidazolyl)borate chemistry. A number of derivatives, including mononuclear triphenylphosphine adducts [(TmtBu)Co(PPh3)]X and dinuclear compounds [Co2(TmtBu)2X]Y, have been prepared in order to ascertain whether cobalt is a reliable surrogate for zinc in biological systems, particularly in sulfur-rich coordination environments. The structure of the first cobaltaboratrane is also reported.
Uninvited Comments From an Uninvited Guest

pose I should be used to it because there seems to be a quota on the number of educators and educational researchers invited to education summits. Worse yet is that many of the contemporary educational problems faced by the nation are in schools that serve our poor inner-city and rural populations, particularly our minority and immigrant populations. The summits are particularly lacking in scholars of color and other educational specialists with ideas about ways to improve schooling for these groups, acknowledged as the least well served in our nation. Maybe it is just as well I was not invited because I would have raised too many difficult questions and made too many negative comments to get along with the industrial and political leaders of the nation. Had I been given the opportunity, I would have asked first: Why is business so keen on judging education in the U.S. to be a failure? We all admit that public education has its warts and something needs to be done about them, but the overall system of public education in the U.S. does not seem to be causing business any harm. On the other hand, a case could be made that business is slandering public education and causing considerable harm to public education! We shall look at these issues next.
Jaw registrations and articulators.

The number and types of records of jaw relationships that a dentist makes for a prosthodontic patient are the products of his philosophy of occlusion and the type of equipment he uses. The three major types of articulators and their use are discussed.
Scalable load balancing strategies for parallel A* algorithms

Abstract In this paper, we develop load balancing strategies for scalable high-performance parallel A* algorithms suitable for distributed-memory machines. In parallel A* search, inefficiencies such as processor starvation and search of nonessential spaces (search spaces not explored by the sequential algorithm) grow with the number of processors P used, thus restricting its scalability. To alleviate this effect, we propose a novel parallel startup phase and an efficient dynamic load balancing strategy called the quality equalizing (QE) strategy. Our new parallel startup scheme executes optimally in Θ(log P) time and, in addition, achieves good initial load balance. The QE strategy prossess certain unique quantitative and qualitative load balancing properties that enable it to significantly reduce starvation and nonessential work. Consequently, we obtain a highly scalable parallel A* algorithm with an almost-linear speedup. The startup and load balancing schemes were employed in parallel A* algorithms to solve the Traveling Salesman Problem on an nCUBE2 hypercube multicomputer. The QE strategy yields average speedup improvements of about 20-185% and 15-120% at low and intermediate work densities (the ratio of the problem size to P), respectively, over three well-known load balancing methods-the round-robin (RR), the random communication (RC), and the neighborhood averaging (NA) strategies. The average speedup observed on 1024 processors is about 985, representing a very high efficiency of 0.96. Finally, we analyze and empirically evaluate the scalability of parallel A* algorithms in terms of the isoefficiency metric. Our analysis gives (1) a Θ(P log P) lower bound on the isoefficiency function of any parallel A* algorithm, and (2) a general expression for the upper bound on the isoefficiency function of our parallel A* algorithm using the QE strategy on any topology-for the hypercube and 2-D mesh architectures the upper bounds on the isoefficiency function are found to be Θ(P log2P) and Θ(P[formula]), respectively. Experimental results validate our analysis, and also show that parallel A* search has better scalability using the QE load balancing strategy than using the RR, RC, or NA strategies.
Neutron resonance spectroscopy: Aluminum

The results are presented for high resolution neutron time of flight measurements on $^{27}\mathrm{Al}$ from 4 to 420 keV. The $R$-matrix multilevel shape analysis was used to obtain the resonance parameters for seven levels to 220 keV. We determined the strength functions as $10^{4}S_{0}=({3.25}_{\ensuremath{-}1.7}^{+4.5})$ and $10^{4}S_{1}=({1.8}_{\ensuremath{-}1.1}^{+3.5})$. A channel radius of 4.2 fm was used in the calculation of $p$-strength function. The (${E}_{0}, l, J, {\ensuremath{\Gamma}}_{n}$) choices were (5.895, 1, 1, 0.017), (34.59, 0, 2, 3.0), (85.69, 0, 3, 11.0), (119.6, 1, 2, 3.6), (142.0, 0, 3, 19.0), (158.2, 1, 3, 3.2), and (202.2, 0, 2, 14.5), where ${E}_{0}$ and ${\ensuremath{\Gamma}}_{n}$ are in keV.