cssi/SciSciGPT-SciSciNet huggingface dataset:
Properties of adenylate cyclase and cyclic nucleotide phosphodiesterase in hamster isolated capillary preparations

Abstract Capillaries isolated by collagenase digestion of hamster epididymal fat pads were used to examine the properties of endothelial adenylate cyclase and cyclic nucleotide phosphodiesterase. Adenylate cyclase activity in capillary homogenates was increased by 10 μM GTP or 100 μM isoproterenol. Lower concentrations of the catecholamine and 5.7 μM prostagladin E1 did not stimulate endothelial adenylate cyclase activity unless GTP was included in the assay system. The effects of isoproterenol on capillary adenylate cyclase activity were blocked by propranolol, but were not affected by phentolamine. Phosphodiesterase activity in endothelial homogenates showed anomalous kinetic behavior with either cyclic AMP or cyclic GMP as the enzyme substrate. At substrate concentrations below 1 μM, capillary phosphodiesterase activity hydrolyzed cyclic GMP 2–6 times faster than cyclic AMP. However, at high substrate levels, e.g., 100 μM, cyclic AMP and cyclic GMP were degraded at similar rates. Hydrolysis of 1 μM cyclic AMP by capillary homogenates was stimulated by 0.1 and 1 μM cyclic GMP. Caffeine, 1-methyl-3-isobutylxanthine, papaverine and dipyridamole SQ 20009 were effective inhibitors of capillary phosphodiesterase activity. In contrast, imidazole enhanced the activity of the enzyme. The presence of adenylate cyclase and phosphodiesterase activities in enzyme. The presence of adenylate cyclase and phosphodiesterase activities in hamster isolated capillaries is consistent with a role for cyclic AMP in the regulation of endothelial function. Moreover, the experiments described here indicate that hamster isolated capillaries are useful model systems for studying the metabolism of vascular endothelium.
Acceptable Versus Straightforward Game Forms: An Example

The description of social decision mechanisms as non-cooperative game forms has recently been the subject of much research. This note concerns two properties of game forms which have attracted particular interest. Hurwicz and Schmeidler (1978) studied game forms which are acceptable in the sense that every profile of player characteristics admits a Nash equilibirum and every Nash equilibrium outcome is Pareto optimal. Gibbard (1973) termed a game form straightforward if there is a dominant strategy for each player characteristic. To avoid repetition, in this paper the term straightforward will be applied only to game forms with the additional property that every dominant strategy equilibrium is Pareto optimal. This note describes an example of a natural economic decision problem for which there exist non-dictatorial acceptable game forms and non-dictatorial straightforward game forms, but no non-dictatorial game forms have both properties. In other words, any game form with well behaved dominant strategy equilibria must have badly behaved non-dominant strategy equilibria. Moreover, there
Analysis of stable two-dimensional patterns in contractile cytogel

Contractile actomyosin systems play a central role in the generation of intracellular patterns. Models for pattern formation have benefited greatly from the application of mechanochemical theory. However, investigations of the patterns have been primarily qualitative in nature; the two-dimensional nature of the evolving patterns has not yet been addressed mathematically, nor has the evolution of stable heterogeneous steady-state solutions. We consider these issues, supporting our analytical predictions with numerical simulations in one and two spatial dimensions. We show how, for certain gels, the two and three-dimensional tensor equation which describes a balance of forces can be reduced to a reaction-diffusion equation.
Numerical Simulation of Pre- and Postsurgical Flow in a Giant Basilar Aneurysm

Computational modeling of the flow in cerebral aneurysms is an evolving technique that may play an important role in surgical planning. In this study, we simulated the flow in a giant basilar aneurysm before and after surgical takedown of one vertebral artery. Patient-specific geometry and flowrates obtained from magnetic resonance (MR) angiography and velocimetry were used to simulate the flow prior to and after the surgery. Numerical solutions for steady and pulsatile flows were obtained. Highly three-dimensional flows, with strong secondary flows, were computed in the aneurysm in the presurgical and postsurgical conditions. The computational results predicted that occlusion of a vertebral artery would result in a significant increase of the slow flow region formed in the bulge of the aneurysm, where increased particle residence time and velocities lower than 2.5 cm/s were computed. The region of slow flow was found to have filled with thrombus following surgery. Predictions of numerical simulation methods are consistent with the observed outcome following surgical treatment of an aneurysm. The study demonstrates that computational models may provide hypotheses to test in future studies, and might offer guidance for the interventional treatment of cerebral aneurysms.
RADIATIVELY SELF-COOLED PENNING-TRAPPED ELECTRONS : A NEW WAY TO MAKE GAS-PHASE NEGATIVE IONS FROM NEUTRALS OF LOW ELECTRON AFFINITY

We present a new method for attachment of self-cooled electrons to gas-phase neutrals of potentially low electron affinity. The cyclotron frequency of electrons in a Penning trap operated at 3 T is...
WE-B-I-618-02: Digital Image Displays — Resolution, Brightness, and Grayscale Calibration

Digital radiographs from CR, DR, RF, and XA systems are displayed on monitors when the exam is performed, when a radiologist interprets the examination, and when the referring physician or surgeon review the image. The various monitors used typically vary in image quality. Display resolution is influenced by pixel size and viewing distance. Displayed field of view varies with the monitor array size and image zoom. Image brightness influences low contrast detection, peripheral vision, and may effect observer fatigue. The display grayscale influence contrast and may alter the appearance for different viewers unless matched on all monitors. The requirements for resolution, brightness, and grayscale are considered for various situations including RF and XA exam room displays, technologist QC stations, radiologists reading stations, general clinic review stations, surgical display, and conference case presentation. Educational Objectives: 1. Understand how pixel size and viewing distance influence resolution in relation to visual limits of the human eye. 2. Understand how image brightness influences observer performance. 3. Learn how the grayscale characteristics of clinical display systems can be calibrated to match diagnostic systems. 4. Learn the performance characteristics of displays now available for various applications.
Pseudo-umbilical surfaces in euclidean spaces

BY BANG-YEN CHENRecently, the author introduced the notion of αth curvatures of first and secondkinds for surfaces in higher dimensional euclidean space [2, 3]. The main purposeof this paper is to study these curvatures more detail. In §1, we derive someintegral formulas for the αth curvatures of first and second kinds. In §2, we getsome applications of these formulas to pseudo-umbilical surfaces.
OVARIECTOMY SENSITIZES A DELETERIOUS INTERACTION BETWEEN ETHANOL WITHDRAWAL AND AGING TO A GREATER DEGREE AFTER ABRUPT TERMINATION THAN GRADUAL TERMINATION OF ETHANOL

We have demonstrated that abrupt termination of chronic ethanol diet creates lipid peroxidation in young adult rats in a manner protected by endogenous estrogen [(17(-estradiol (E2)]. In this study, we tested whether ovariectomy exacerbates a deleterious interaction between ethanol withdrawal (EW) and age at the levels of oxidative stress using a 3 month ethanol diet paradigm. 5-, 12-, and 16-month-old ovariectomized rats with oil pellet or E2 replacement received a liquid ethanol (6.5%) or control dextrin diet for 3 months. One group was terminated from the ethanol diet by step-down concentrations of ethanol. Another group was terminated from the ethanol diet abruptly. Cerebellum, cortex, hippocampus were collected to assess the levels of carbonyls as a marker of oxidative damage to protein. Compared to groups with control dextrin diet and gradual termination of ethanol diet, EW groups showed a greater increase in protein carbonyls. Such phenomenon was more profound in older rats vs younger rats and more profound in ovariectomized rats vs in ovary intact rats. This increase in carbonyl contents was partially prevented by E2 implantation. These findings suggest that ovariectomy sensitizes brain to a deleterious interaction of EW with age in a manner that is more prominent after abrupt termination than a gradual termination of ethanol of long term ethanol diet (supported by NIAAA AA013864 and AA015982).
The Complementarity View: Exploring a Continuum in Political—Administrative Relations

The politics–administration dichotomy has drawn criticism from contemporary public administration scholars largely because of its lack of descriptive accuracy and particular normative inclinations. In their search for an alternative model to the dichotomy, some scholars developed what is widely known today as complementarity. Although this emerging view received an enthusiastic welcome from many scholars and practitioners, more research has yet to be done to address its conceptual and empirical shortcomings. Using survey data collected from a nationwide sample of city managers, this study explores empirical foundations of the complementarity view of the politics–administration relationship. Specifically, the author first identifies a politics–management continuum based on a review of public administration literature on the complementarity view and then analyzes survey data to see whether the relationship between elected officials and public administrators is characterized by complementarity. The results of the analysis generally support the complementarity view, in that the responses of city managers mostly parallel the idea of a continuum in elected official–public administrator relationships, a continuum that moves from politics on one end to management on the other end, with various policy and administration activities in the middle. This paper aims to make a conceptual and empirical contribution to an important question in public administration.
A Role for Loop F in Modulating GABA Binding Affinity in the GABAA Receptor

Abstract The brain's major inhibitory neuroreceptor is the ligand-gated ion channel γ‐aminobutyric acid (GABA) type A receptor (GABAR). GABARs exist in a variety of different subunit combinations that act to modulate the physiological behavior of GABAR by altering its pharmacological profile, as well as its affinity for GABA. While the α 1 β 2 γ 2 subtype is one of the most prevalent GABARs, the less populous α 6 β 3 δ subtype has much higher GABA sensitivity. Previous studies identified residues crucial for GABA binding; however, the specific molecular differences responsible for this diverse sensitivity are not known. Furthermore, the role of loop F is a divisive subject, with conflicting evidence for ligand binding function. Using homology modeling, ligand docking, and molecular dynamics simulations, we investigated the GABA binding sites of the two receptor subtypes. Simulations identified seven residues that consistently interacted with GABA in both subtypes: αF65, αR132, βL99, βE155, βR/K196, βY205, and βR207. Residue substitution at position β196 (arginine in α 6 β 3 δ, lysine in α 1 β 2 γ 2 ) resulted in a shift in GABA binding. However, the major difference between the two binding sites was the magnitude of loop F involvement, with a greater contribution in the α 6 β 3 δ receptor. Free energy calculations confirm that the α 6 β 3 δ binding pocket has an increased affinity for GABA. Thus, the possible role for loop F across the GABAR family is to modulate GABA affinity.
Fiscal Pressure?: The Impact of Elder Recruitment on Local Expenditures Daniel R. Mullins

Several states and cities have developed policies designed to attract retirees, hoping to position their communities as future homes for the retirement years of high-spending, low-service-consuming elders. In this article, attention is focused on issues of public expenditures. Although near-retirement-age populations seem to have lower demands for public goods, these preferences quickly change, and communities with larger proportions of postretirement people in their population spend more for public services. Political tensions may result. Thus there may be no economic boom in attracting retirement or preretirement-age populations to a community.
Transference number measurements of TiO2-BaO melts by stepped-potential chronoamperometry

TiO2–BaO melts have been under investigation as candidate electrolytes for the electrolytic production of titanium. Transference number measurements have been made by stepped-potential chronoamperometry at two compositions: 67 mol% TiO2 (1328<T<1487°C) and 73 mol% TiO2 (1210<T<1477°C). A theoretical analysis of the technique, capable of distinguishing between variations in ion density and variations in net free-charge density, is presented.
Re-exposure of captive house finches that recovered from Mycoplasma gallisepticum infection.

Fourteen house finches were reinoculated (re-exposed) with 0.05 ml (3.24×105 colony forming units/ml) of Mycoplasma gallisepticum (MG) in the conjunctival sac of each eye. All birds used in this reinoculation study had recovered from previous infection between 27 and 83 days after inoculation. Recovery was based on the absence of clinical signs of conjunctivitis and/or the inability to detect MG in conjunctival or choanal samples. Birds were maintained in individual cages under controlled environmental conditions at temperature 21–24 C, relative humidity 70%, and a light cycle adjusted to ambient values. They were divided into three groups, (A, B, and C). Five birds each were reinoculated 219 days (7.3 mo, group A) and 314 days (10.47 mo, group B) after the original infection. The final group of four birds was reinoculated at 425 days after experimental infection (14.17 mo, group C). Although the birds were randomly assigned to the three groups, the duration of the disease state (number of days until clin...
Derivatization of peptides to enhance ionization effiency and control fragmentation during analysis by fast atom bombardment tandem mass spectrometry

Novel and simple procedures for preparing ethyl-triphenylphosphonium derivatives of peptides are described. These procecores allow an ethyl-triphenylphosphonium moiety to be selectively attached to either the N- or C-terminus. The resulting derivatives contain a positive charge at a fixed position and have significant hydrophobic character. Modification of peptides by these chemical methods significantly enhances the efficiency of fast atom bombardment ionization, especially of hydrophilc peptides. Moreover, upon collisionally activated dissociation, the deriva-tized peptides generate a predictable series of sequence ions from either the C-terminus or the N-terminus, depending on the location of the ethyl-triphenylphosphonium moiety.
GameX: a platform for incremental instruction in computer graphics and game design

Recent trends have resulted in an increased focus on game design as a topic for teaching in higher education [Deutsch 2002]. Although many game engines currently exist, few of these were designed with educational goals in mind. We distinguish between industry-oriented engines and instructional game engines designed to teach a range of concepts. The features needed to teach game development to college undergraduates in engineering and the humanities are explored. Specifically, we develop a platform that supports incremental education in game design. GameX, an open source instructional game engine, was developed with this approach in mind and was used to initiate the Game Design Initiative at Cornell University (GDIAC).
Asymmetric modelling of the revenue-expenditure nexus: evidence from aggregate state and local government in the US

This study examines the time series dynamics between US aggregate state and local government receipts and expenditures in differentiating between four hypotheses related to the revenue-expenditure nexus: tax-spend, spend-tax, fiscal synchronization and institutional separation hypotheses. Unlike previous research at the state and local level, the possibility of asymmetries in the budgetary process is explored using the threshold autoregressive (TAR) and momentum threshold autoregressive (MTAR) cointegration framework of Enders and Siklos (2001). The results indicate the absence of any asymmetries (TAR or MTAR) in the adjustment towards budgetary equilibrium. The symmetric error correction model provides support for the spend-tax hypothesis.
The effect of amiloride analogs on taste responses in gerbil.

Abstract Amiloride analogs that were designed to inhibit three types of Na + transport systems (the epithelial Na + channel, the Na + H + antiporter, and the Na + Ca ++ exchanger) were applied to the tongue of the gerbil to determine their effects of electrophysiological taste responses to NaCl, CaCl 2 , sucrose, and glutamic acid. The pattern of responses from the chorda tympani nerve indicates that the taste of NaCl is almost totally accounted for by the epithelial Na + channel. Phenamil, an amiloride analog which specifically blocks the epithelial Na + channel at low concentrations, suppressed the taste responses to 0.03 M NaCl by 97%. The pattern of responses also indicates that the Na + H + antiporter and the Na + Ca 2+ exchanger do not mediate salt taste in the gerbil. None of the amiloride analogs blocked taste responses to CaCl 2 , sucrose, or glutamic acid. It is concluded that the salty taste of NaCl in the gerbil is almost totally mediated by the epithelial Na + channel, and the kinetics of this channel are identical to amiloride-sensitive sodium channels in other systems.
Activity of the Agrobacterium T-DNA transfer machinery is affected by virB gene products.

The oriT (origin of transfer) sequence and mob (mobilization) genes of plasmid RSF1010 can functionally replace transfer DNA (T-DNA) borders to generate an RSF1010 intermediate transferable to plants through activities of the tumor-inducing (Ti)-plasmid virulence (vir) genes of Agrobacterium tumefaciens. Because the Ti plasmid virB gene products are hypothesized to form a membrane-localized T-DNA transport apparatus, we investigated whether specific virB genes were needed for RSF1010 transfer. Here we report that transformation of Nicotiana tabacum leaf explants by an RSF1010-derivative plasmid (pJW323) requires the essential virulence genes virB9, virB10, and virB11, consistent with the hypothesis that both the T-DNA and RSF1010 transfer intermediates utilize the same transport machinery. Further, while pJW323 is transferred into plant cells by Agrobacterium strains harboring both pJW323 and pTiA6, the initiation of crown gall tumors (i.e., T-DNA transfer) is greatly suppressed. Coordinate overexpression of the virB9, virB10, and virB11 gene products relieves pJW323-mediated oncogenic suppression and restores tumorigenicity, but does not increase the transfer frequency of pJW323 into plant cells. We propose that the virB9, virB10, and virB11 gene products function coordinately and stoichiometrically to enhance DNA transfer in a fashion specific for the T-DNA intermediate.
An Exploratory Optimization Plus Kalman Filtering Based Method for Parameter Estimation in Model Based Diagnostics

Physics based models can be used to detect and isolate system faults. As a machine degrades, system outputs deviate from desired outputs, generating residuals defined by the error between sensor measurements and corresponding model simulated signals. Residuals contain valuable information to interpret system states and parameters. A framework for parameter estimation and system identification of non-linear dynamical systems is presented with focus on DC motors and 3-phase induction motors. Tuning combines artificial intelligence techniques like Quasi-Monte Carlo sampling (Hammersley sequencing) and Genetic Algorithm (NSGA II) with an Extended Kalman filter (EKF) that utilizes the system dynamics information via physical models. A tentative Graphical User Interface (GUI) simplified interactions between machine operator and module. Implementation details and results comparing healthy and faulty systems are included.Copyright © 2011 by ASME
Near- versus mid-infrared diffuse reflectance spectroscopy for the quantitative determination of the composition of forages and by-products

The objective of this work was to explore the relative value of near- and mid-infrared diffused reflectance spectroscopy in determining the composition of forages and by-products. Sixty-seven sampl...
The crystal ball of research: how to use it to learn about the user community

With computing becoming more diverse and ubiquitous, it will be increasingly important in the future for user services departments to learn about the characteristics and needs of the people we serve. As a research psychologist working at Yale's Computer Center, I have spent much of my time during the past year developing a research program to do just that. This paper will detail the development of the research agenda, describing the process involved, the program itself, and results we've obtained so far. I will end by offering suggestions on how other universities can develop their own user research programs.
Mohs Micrographic Surgery: How ACMS Fellowship Directors Practice

BACKGROUND Mohs micrographic surgery (MMS) is widely employed in the removal of skin cancer. As this technique becomes more widely employed, it is useful to establish the patterns of care provided by American College of Mohs Surgery (ACMS)-approved fellowship directors. OBJECTIVE To compile and analyze data collected annually by the ACMS to determine practice patterns and trends in MMS as performed by ACMS-approved fellowship directors. MATERIALS AND METHODS A retrospective study of case logs from 50 fellowship directors obtained from the ACMS detailing case volume, type of cancer treated, location, lesion size, wound size, number of stages, referral percentage, and type of repairs performed. RESULTS Annual case volume per surgeon has increased linearly. The incidence of squamous cell carcinoma treated using MMS is rising steadily. The size of lesions treated using MMS has decreased slightly over several decades, as has the number of stages of MMS taken per lesion. The majority of MMS performed by fellowship directors is for skin cancer on the face. Dermatologic surgeons perform most of their own reconstructions. Academic and private fellowship practice patterns are nearly identical. CONCLUSIONS ACMS-approved fellowship directors use MMS mainly for facial skin cancers, and they perform most of their own reconstructions. Practice patterns for most fellowship directors are similar. Private fellowships and academic fellowships are similar in scope and practice. CONCLUSIONS The authors have indicated no significant interest with commercial supporters.
Accessibility now!: teaching accessible computing at the introductory level

As ASSETS attendees, we are clearly interested in promoting accessibility in computing. One way to do this is to teach courses on the topic. Most such courses are aimed at upper-level students. But why wait? It's possible to teach accessibility immediately at the introductory level, thereby affecting a greater number of students. I offer a description of a course in computer science that accomplishes this.
Effects of Ca2+ ionophore A23187 and Ca2+ deficiency on pancreatic phospholipids and amylase release in vitro.

Abstract The Ca 2+ ionophore A23187 elicits a transient increase in pancreatic amylase release in vitro, and this is accompanied by a transient decrease in phosphatidyl inositol concentration. Effects of ionophore A23187 and carbachol on amylase release and phosphatidylinositol breakdown are dependent on medium Ca 2+ . These results suggest that major secretagogue-induced, pancreatic phospholipid changes follow, rather than precede, changes in Ca 2+ in the pancreas.
The Drug Involvement Scale for Adolescents (Disa)

This article specifically addressed the need for a multidimensional approach to measuring adolescents' drug involvement. The Drug Involvement Scale for Adolescents (DISA) was theoretically specified and its measurement properties were tested using Confirmatory Factor Analyses and traditional procedures with 705 high-risk and typical high school students. Five first-order dimensions, Drug Access, Alcohol Use, Other Drug Use, Drug Use Control Problems and Adverse Drug Use Consequences, and a hierarchical model of Drug Involvement demonstrated a good fit between model and data. Further, the DISA demonstrated good internal consistency (alpha = .91); correlated as expected with known correlates of adolescent drug use; discriminated drug involvement between high-risk and typical high school students; and predicted later drug involvement and known drug-related consequences among adolescents. The results suggest the DISA should be useful for capturing a multidimensional view of adolescent drug involvement in both etiologic and prevention studies. A major advantage of the DISA is its brevity: twenty-two indicators constructed from twenty-nine items.
Hydrolysis of Ribulose-1,5-bisphosphate Carboxylase by Endoproteinases from Senescing Barley Leaves

The hydrolysis of (14)C-labeled ribulose-1,5-bisphosphate carboxylase (RuBPCase) by two partially purified endoproteinases from senescing barley (Hordeum vulgare v. Numar) leaves is described. The major thiol proteinase, EP(1), exhibits biphasic kinetics which appear to be caused by a region of the large subunit of RuBPCase that is highly sensitive to attack by EP(1). This proteinase further hydrolyzes both the large and small subunit to smaller peptides. A second proteinase, EP(2), appears to convert the small subunit of RuBPCase rapidly to a 13.7-kilodalton fragment during initial stages of hydrolysis and then to degrade both this fragment and the large subunit. The presence of a third endoproteinase, EP(3), was discovered when [(14)C]RuBPCase, which appeared to be homogeneous by sodium dodecyl sulfate polyacrylamide electrophoresis, seemed to undergo very low but significant rates of "autolysis." The large molecular weight fragments produced by EP(3) were different from those of EP(1) and EP(2).
Memory System Optimization for FPGA-Based Implementation of Quasi-Cyclic LDPC Codes Decoders

Designers are increasingly relying on field-programmable gate array (FPGA)-based emulation to evaluate the performance of low-density parity-check (LDPC) codes empirically down to bit-error rates of 10-12 and below. This requires decoding architectures that can take advantage of the unique characteristics of a modern FPGA to maximize the decoding throughput. This paper presents two specific optimizations called vectorization and folding to take advantage of the configurable data-width and depth of embedded memory in an FPGA to improve the throughput of a decoder for quasi-cyclic LDPC codes. With folding it is shown that quasi-cyclic LDPC codes with a very large number of circulants can be implemented on FPGAs with a small number of embedded memory blocks. A synthesis tool called QCSyn is described, which takes the H matrix of a quasi-cyclic LDPC code and the resource characteristics of an FPGA and automatically synthesizes a vector or folded architecture that maximizes the decoding throughput for the code on the given FPGA by selecting the appropriate degree of folding and/or vectorization. This helps not only in reducing the design time to create a decoder but also in quickly retargeting the implementation to a different (perhaps new) FPGA or a different emulation board.
Xenograft Models for Liver Metastasis: Relationship between Tumor Morphology and Adenovirus Vector Transduction

The improvement of initial tumor cell transduction with viral vectors is a major task in tumor gene therapy. We have developed mouse tumor models with hepatic metastases to study transduction of tumor cells after systemic adenovirus vector application. The tumor models were established by intraportal transplantation of human tumor cell lines into immunodeficient mice. Liver metastases derived from cervix, colon, breast, and liver cancer lines were analyzed for distribution of extracellular matrix, vascularization, and transgene expression after tail vein injection of adenovirus vectors. Overall, xenografts resembled the morphology of corresponding tumors in cancer patients. Adenovirus-mediated gene delivery depended on tumor vascularization and direct contact between blood vessels and tumor cells. These models represent important tools for studying and improving tumor gene therapy approaches.
Conformations of the central transforming region (Ile 55-Met 67) of the p21 protein and their relationship to activation of the protein.

The GTP-binding p21 protein, encoded by the ras-oncogene, becomes transforming if amino acid substitutions are made at critical positions in the polypeptide chain, e.g., at Gly 12, Gly 13, Ala 59, Gln 61 and Glu 63. Most of these substitutions occur in two phosphate-binding loop regions, Tyr 4-Thr 20, herein designated as segment 1, and Ile 55-Met 67, herein designated as segment 2. These two segments are homologous to two corresponding regions in the two purine nucleotide binding proteins, bacterial elongation factor (EF-tu) (Val 12-Thr 28 corresponds to segment 1; His 78-Ile 92 corresponds to segment 2) and adenylate kinase (ADK) (Lys 9-Cys 25 corresponds to segment 1 and Tyr 95-Arg 107 corresponds to segment 2). We find that the conformations of the segment 1 region in the p21 protein, EF-tu and ADK are similar to one another and that the conformation of the segment 2 region of EF-tu is superimposable on that of segment 2 of ADK. Furthermore, the relative position of the two segments in EF-tu is strikingly similar to that of the two segments in ADK. In the originally proposed X-ray structure for the p21 protein, the conformation of segment 2 in the p21 protein is not similar to that found for the other two proteins, and its disposition relative to segment 1 and the remainder of the protein is also different from that observed for the other two proteins. We previously computed the low-energy conformations for segment 2 in the p21 protein using conformational energy calculations based on ECEPP (Empirical Conformational Energy Program for Peptides) with Gln, Pro, Leu, Lys, and Arg at positions 61. We also predicted that the position of segment 2 in the p21 protein adopts a position and conformation identical to the ones observed in EF-tu and ADK in the activated protein. We now find that the computed global minimum lowest-energy structure is superimposable on segment 2 of EF-tu and on the 95-107 sequence of ADK and that our predicted position for this segment in the activated protein coincides with that found in a more recent X-ray crystallographic structure for the p21 protein.
Autologous buccal mucosal graftfor urethral reconstruction

Abstract Objectives. The search for an adequate tissue for reconstruction of the urethrain those patients with a paucity of local skin continues. Over the past 18 months, the use of buccal mucosa as a substitution for urethra was evaluated. Methods. Six patients who had complex hypospadias had buccal mucosa grafts for urethral reconstruction. All patients had had previous surgery for repair of chordee or significant complications from previous surgery with a result of lack of penile skin. Patients were operated on and followed for 8 to 17 months. Results. Buccal mucosa was used as a rolled tube in 4 patients, an onlay graft in 1, and a folded tube in 1. A urethrocutaneous fistula that was repaired 6 months after the buccal surgery was the only complication. Conclusions. By virtue of its tissue characteristics, ease of handling, and ease ofharvest, buccal mucosa is an excellent tissue for urethral reconstruction.
Aquaculture in Open Systems

Aquaculture systems are very diverse in their design and function. The three most basic categories of culture systems are open, semiclosed and closed systems. Open system culture generally refers to fish farming in natural water bodies such as oceans, bays, estuaries, coastal lagoons, lakes, or rivers. Semiclosed systems are those in which the culture water makes one pass through the system and is discharged. Systems of this nature are referred to as flow-through or once-through systems. The raceway falls into this category. Closed systems are those where the water is reconditioned and recirculated to the culture unit(s). A more recent term for this type system is the closed recirculating system. Various combinations of the latter two system types are in everyday use. The combinations are limited only by the imagination of the aquaculturist. Open system culture is the subject of this chapter. Other systems types are discussed in later chapters.
Metabolic and environmental regulation of 3-methylcrotonyl-coenzyme A carboxylase expression in Arabidopsis.

3-Methylcrotonyl-coenzyme A carboxylase (MCCase) is a nuclear-encoded, mitochondrial biotin-containing enzyme composed of two types of subunits: the biotinylated MCC-A subunit (encoded by the gene At1g03090) and the non-biotinylated MCC-B subunit (encoded by the gene At4g34030). The major metabolic role of MCCase is in the mitochondrial catabolism of leucine, and it also might function in the catabolism of isoprenoids and the mevalonate shunt. In the work presented herein, the single-copy gene encoding the Arabidopsis MCC-A subunit was isolated and characterized. It contains 15 exons separated by 14 introns. We examined the expression of the single-copy MCC-A and MCC-B genes in Arabidopsis by monitoring the accumulation of the two protein and mRNA products. In addition, the expression of these two genes was studied in transgenic plants containing the 1.1- and 1.0-kb 5′ upstream sequences of the two MCCase subunit genes, respectively, fused to the β-glucuronidase gene. Light deprivation induces MCCase expression, which is suppressed by exogenous carbohydrates, especially sucrose. Several lines of evidence indicate that the suppressor of MCCase expression is synthesized in illuminated photosynthetic organs, and can be translocated to other organs to regulate MCCase expression. These results are consistent with the hypothesis that the suppressor of MCCase expression is a carbohydrate, perhaps sucrose or a carbohydrate metabolite. We conclude that MCCase expression is primarily controlled at the level of gene transcription and regulated by a complex interplay between environmental and metabolic signals. The observed expression patterns may indicate that one of the physiological roles of MCCase is to maintain the carbon status of the organism, possibly via the catabolism of leucine.
Silent and Infertile An Intersectional Analysis of the Experiences of Socioeconomically Diverse African American Women With Infertility

To date, the preponderance of research on infertility in the United States has been conducted with affluent, White couples seeking advanced medical interventions. However, racial/ethnic minorities are equally, if not more, likely to experience infertility in the United States. Drawing on qualitative interviews with 50 African American women of different socioeconomic backgrounds, our study uses an intersectional framework to explore the experiences of African American women who cope with infertility. First, we found that experiencing infertility greatly impaired women’s sense of self and gender identity. Moreover, the imperative to be an African American mother was influenced by an interplay of gendered, racial, and religious mandates. Second, women’s relationships with friends and family members were characterized by a deep sense of silence and isolation; several explanations for this finding are proposed, including stereotypes about African American women’s sexuality. Third, interactions with medical pr...
Defectives at the World's Fair Constructing Disability in 1904

ABSTRACTFrom displays of so-called defectives and primitives at the 1904 St. Louis World's Fair, early 20th-century authorities shaped a definition of abnormality that they showed to a curious public. Complementing these displays were discourses about disability that proposed schemes for education, custody, sterilization, and even extermination. Like the displays of defectives, the discourses about defectives paralleled discourses about primitive races that appeared at the turn of the century to rationalize American imperialism. Together, the displays and discourses of defectives and primitive races shaped an understanding of science and education. In so doing, they also provided American elites a way of distinguishing between improvable and unimprovable inferiors (see Note).
Vulnerability and the Patient–Practitioner Relationship: The Roles of Gatekeeping and Primary Care Performance

Objectives. We examined whether patients’ perceptions of their relationships with primary care practitioners (PCPs) vary by vulnerability status and assessed the extent to which gatekeeping arrangements and primary care performance moderate potential disparities. Methods: We used the nationally representative 1996–1997 Community Tracking Study Household Survey as our data source. Results. Whites reported better patient–practitioner relationships than minorities. Requirements that patients select a PCP and obtain referral authorization neither reduced nor exacerbated racial disparities in the patient–practitioner relationship. On the other hand, access to and continuity with a PCP substantively reduced disparities, especially for the most vulnerable group. Conclusions. Enhancing primary care performance may reduce some of the barriers to care experienced by vulnerable populations, thereby improving patients’ relationships with their PCPs.
Governing agriculture-forest landscapes to achieve climate change mitigation

Abstract This introduction to the special section on “Governing Agriculture-Forest Landscapes to Achieve Climate Change Mitigation” reviews external interventions to improve forest conditions and reduce deforestation, and by extension, influence carbon storage in agriculture-forest landscapes. The review is based on a careful survey of 123 cases of project-based and policy interventions to influence land use and forest cover outcomes. We propose that outcomes of interventions can be explained in terms of rights, incentives, and technologies related to land use and apply this framework to examine 12 types of interventions in agriculture-forest landscapes. The analysis of the identified 123 cases raises concerns about consistency of data and comparability of cases. Our preliminary evidence suggests limited association between the stated objective of an intervention and its success. This evidence also suggests that smaller scale and effective enforcement may be positively associated with improved forest outcomes. But the effectiveness of interventions across different agriculture-forest landscapes varies and available evidence does not permit easy generalizations. The variable effects of interventions across different agriculture-forest landscapes point to the need to better understand the forms and functions of interventions and to problems associated with assessing their relative efficacy.
Static analysis for inference of explicit information flow

This paper proposes a new static analysis for inference of explicit information flow. The analysis is context-sensitive, cubic, and works both on complete programs and software components. We perform experiments on several Java components which show that the analysis is precise and practical. Thus, the analysis can be incorporated in program understanding and verification tools and help verify security properties in a light-weight, practical manner.
Factors influencing burrow length and depth of ground-dwelling squirrels

We reviewed the literature on burrows of North American ground-dwelling squirrels to assess factors influencing burrow length and depth. Prior research suggested that soil characteristics and burrow age can influence burrow dimensions; we extended these findings by evaluating the influence of body size, temperature stress, and degree of sociality. We found that body size was positively correlated with burrow length and depth, probably because larger species require more space for underground activities. This relationship did not hold for Marmota monax and M. flaviventris, for unknown reasons. Burrow length scaled allometrically with body mass (b = 0.72), possibly because the metabolic effects of limited ventilation in burrows placed a constraint on burrow length. Temperature stress was not related to burrow depth, perhaps because of the insulation provided by snow and soil. The more highly social species excavated longer burrow systems, probably because of the greater space needs of multiple residents per burrow.
Characteristics of human knee muscle coordination during isometric contractions in a standing posture: the effect of limb task.

Abstract Different functional roles for the hands have been demonstrated, however leg control is not as well understood. The purpose of the present study was to evaluate bilateral knee neuromuscular control to determine if the limb receiving greater attention would have more well-tuned control compared to an unattended limb. Surface electrodes were placed on seven muscles of each limb, before standing on two force platforms. Visual feedback was given of the forces and moments of the "focus limb," but not the "unattended limb." Static isometric forces were matched with their focus limb, requiring their unattended limb to push in the opposite direction, using a combination of forward–backward–medial–lateral shear forces while muscle activity was collected bilaterally. There was a significant main effect for limb task ( p =0.02), with the medial hamstrings being more specific ( p =0.001) while performing the unattended limb and the lateral hamstring being more well-tuned ( p =0.007) while performing the focus limb task. The focus limb's medial and lateral gastrocnemius were principally active in the forwards direction, but only the unattended limb's lateral gastrocnemius was active in the backwards direction. Findings suggest unique neuromuscular control strategies are used for the legs depending on limb task.
Toward a theory of indexing—II

The purpose of this paper is to present the elements of a basis for a theory of information storage and retrieval. It is believed that this theory can best be formulated in terms of a general theory of indexing. After stating basic premises and defining essential concepts, the relationship between a theory of indexing and a theory of information storage and retrieval is considered. The similarities between the indexing process and the general communication process are discussed, and indexing is viewed as an order increasing (i.e., entropy decreasing) operation. The concept of a theoretical index is developed and contrasted with real-world indexing systems. The relationship between query formulation, retrieval, and benefit is discussed, and these notions are then related to the human performance variable. It is believed that the ideas presented in this paper provide a useful framework for more detailed investigations into the indexing process.
Variable phosphate-mediated regulation of vitamin D metabolism in the murine hypophosphatemic rachitic/osteomalacic disorders.

The familial hypophosphatemic (vitamin D-resistant) disorders are a variety of genetic and acquired syndromes that exhibit unexpected biochemical heterogeneity, manifest as variably abnormal or apparently normal regulation of 1,25-dihydroxyvitamin D [1,25-(OH)2D] production. Recently, we observed that Hyp and Gy mice, murine homologs of Xlinked hypophosphatemic rickets, exhibit similarly disparate regulation of vitamin D metabolism. While Gy mice under basal conditions maintain an appropriate elevation (relative to hypophosphatemia) of renal 25-hydroxyvitamin D (25OHD)-lα-hydroxylase, Hyp mice manifest only normal, not increased, enzyme activity. Whether such diversity results from maintenance of phosphate (P)-regulated 1,25-(OH)2D production in Gy mice and loss of this function in Hyp mice or from other variations remains unknown. Therefore, we examined the integrity of Pregulated enzyme activity in the Gy and Hyp mice by testing the effects of enzyme inhibition and alteration of the serum phosphorus con...
The Economics of Healthcare Rationing

This article examines the economics of healthcare rationing. We begin with an overview of the various dimensions across which healthcare rationing operates, or at least has the potential to operate, in the first place. We then describe the types of economic analyses used in healthcare rationing decision-making, with particular reference to cost-benefit analysis and cost-effectiveness analysis. We also discuss healthcare rationing in practice, such as how economic analyses inform decisions regarding which services to cover, and conclude by discussing various practical and conceptual challenges that may arise with economic analyses and that span both economics and ethics.
Improving performance of Java applications using a coprocessor

Summary form only given. Java technology is becoming a significant force stimulating the evolution of embedded systems. One of the problems in front of it is its poor performance. An important component of this performance problem is the overhead time spent during dynamic compilation. We demonstrate that a dual-processor heterogeneous architecture that employs both a conventional CPU and a Java coprocessor dedicated to compilation can be very effective in hiding the time spent in dynamic compilation. We propose two different profile-driven algorithms that make use of such a coprocessor based system, and evaluate them using a set of Java benchmarks. Our results clearly indicate that it is possible to improve overall performance by intelligently scheduling dynamic compilations on the coprocessor.
An IR study to optimize the absorption coefficient of cadmium stannate

Abstract Cadmium stannate (3Cd 2 SnO 4 /CdSnO 3 ) has been shown to exhibit broad band IR absorption over the wavelength range 3–12 μm. The intensity and position of the band maximum arise from “free” electrons present in the conduction band of the semiconductor. To enhance the absorption coefficient, we have studied the electron-donating properties of antimony dopant and the lattice defects arising from high temperature, vacuum and hydrogen exposure treatments. Our results demonstrate that appropriate dopant and treatment conditions generate cadmium stannate having an absorption coefficient value of greater than 3000 cm 2 g . In support of these findings, X-ray diffraction analysis has identified phase changes that occur in conjunction with variations in optical properties.
NON-RECURSIVE TRADE-OFFS FOR TWO-WAY MACHINES

If the machines of some type A have enough resources to (i) solve problems that no machine of type B can solve, and (ii) simulate any unary two-way deterministic finite automaton that has access to a linearly-bounded counter, then typically no recursive function can upper bound the increase in the size of description when a machine of type A is replaced by an equivalent machine of type B.
Business: The Ultimate Resource

Can any book that includes ultimate resource in the title ever live up to the hype? In this case, Business: The Ultimate Resource comes close to reaching such a lofty claim. The reference work cove...
Reduction of experimental necrotizing enterocolitis with anti-TNF-α

Necrotizing enterocolitis (NEC) is the most common gastrointestinal disease of premature infants. However, despite significant morbidity and mortality, the etiology and pathogenesis of NEC are poor...