cssi/SciSciGPT-SciSciNet huggingface dataset:
Fast Ignitron Trigger Circuit Using Insulated Gate Bipolar Transistors

This paper describes a low cost, easy-to-implement circuit for triggering ignitrons in plasma physics experiments and other pulsed power applications. Using insulated gate bipolar transistors (IGBTs) for rapid switching, the circuit delivers >2 peak current from a 0.1-μF capacitor to the ignitron trigger pin with a rise time of ~ 0.6 μs. The trigger circuit is isolated from the ignitron by a pulse transformer. Details of the circuit design and practical considerations for working with IGBTs are discussed. Sources of inductance in the system are identified, and leakage inductance associated with the pulse transformer is shown to be the primary factor limiting the pulse rise time.
Improving GA search reliability using maximal hyper-rectangle analysis

In Genetic algorithms it is not easy to evaluate the confidence level in whether a GA run may have missed a complete area of good points, and whether the global optimum was found. We accept this but hope to add some degree of confidence in our results by showing that no large gaps were left unvisited in the search space. This can be achieved to some extent by inserting new individuals in big empty spaces. However it is not easy to find the biggest empty spaces, particularly in multi-dimensional problems. For a GA problem, however, it is not necessary to find the exact biggest empty spaces; a sufficiently large empty space is good enough to insert new individuals. In this paper, we present a method to find a sufficiently large empty Hyper-Rectangle for new individual insertion in a GA while keeping the computational complexity as a polynomial function. Its merit is demonstrated in several domains.
The Impact of Wireless Technology Feedback on Inventory Management at a Dairy Manufacturing Plant.

Replacing the method of counting inventory from paper count sheets to that of wireless reliably reduced the elapsed time to complete a daily inventory of the storage cooler in a dairy manufacturing plant. The handheld computers delivered immediate prompts as well as auditory and visual feedback. Reducing the time to complete the daily inventory allowed the production planner to prepare the day's manufacturing schedule earlier in the day, thereby leading to more efficient downstream processes. The two inefficiencies noted with the original paper count sheets, such as flipping pages to locate an item in relation to its storage location and hand-entered data into the computer inventory tables, were eliminated immediately at implementation. The role of the organizational behavior management practitioner in designing work procedure changes using technical solutions, requiring a minimum of training, to accelerate key operational processes was examined.
Bi-directional Regulation between Tyrosine Kinase Etk/BMX and Tumor Suppressor p53 in Response to DNA Damage

Etk/Bmx, a member of the Tec family of nonreceptor tyrosine kinases, has been implicated in the regulation of various cellular processes including proliferation, differentiation, motility, and apoptosis. Here, we report the identification of Tec family kinases as the potential interacting proteins of the tumor suppressor p53 by an Src homology 3 domain array screening. Etk is physically associated with p53 through its Src homology 3 domain and the proline-rich domain of p53. Induction of p53 expression by DNA damage inhibits Etk activity in several cell types. Down-regulation of Etk expression by a specific small interfering RNA sensitizes prostate cancer cells to doxorubicin-induced apoptosis, suggesting that inhibition of Etk activity is required for apoptosis in response to DNA damage. We also show that Etk primarily interacts with p53 in the cytoplasm and that such interaction leads to bidirectional inhibition of the activities of both proteins. Overexpression of Etk in prostate cancer cells results in inhibition of p53 transcriptional activity and its interaction with the mitochondrial protein BAK and confers the resistance to doxorubicin. Therefore, we propose that the stoichiometry between p53 and the Tec family kinases in a given cell type may determine its sensitivity to chemotherapeutic drugs.
Preoperative two-dimensional echocardiographic prediction of prosthetic aortic and mitral valve size in children.

Abstract Preoperative two-dimensional echocardiograms (2D-ECHOs) were done on 18 patients to determine the accuracy of assessing the mitral and aortic anulus diameter in children undergoing valve replacement. Fourteen patients underwent primary valve replacement and four underwent repeat valve replacement. The mean age was 11.5 years (range 2 to 17 years). The 2D-ECHO measured mitral or aortic valve anulus was compared with the external diameter of the largest prosthetic valve that could be inserted. There was a strong correlation ( r = 0.99, p r = 0.16, p = NS) was poor for those undergoing repeat valve replacement. In conclusion, 2D-ECHO prediction of prosthetic mitral and aortic valve size is accurate in children undergoing primary valve replacement but is poor in those undergoing repeat valve replacement.
A Single Amino Acid Mutation in the Drosophila Myosin SH1 Domain Severely Affects Muscle Function, Myofibril Structure, Myosin Enzymatic Activity, and Actin Sliding Velocity

Hereditary inclusion-body myopathy type III (IBM-3) is caused by a single amino acid Glu706Lys substitution in the SH1 helix of the myosin head. The SH1 domain has been proposed to play a key role in the conformational changes that occur in the myosin head during force generation which is coupled to ATP hydrolysis. We are using an integrative approach to study the structure-function relationship of the myosin SH1 domain in the Drosophila model system. We constructed a gene encoding myosin with the single amino acid mutation and expressed it in place of wild-type myosin heavy chain by germline transformation and crossing into a line that lacks myosin in its flight and jump muscles. The homozygous flies are flightless and their jump abilities are also greatly reduced. The indirect flight muscle fibers of young flies show considerable ultrastructural disarray, with some regions of missing thick and thin filaments, and myofibrils that are not uniform in width. Our initial study showed that actin sliding velocity and basal and actin stimulated ATPase were reduced more than 70% compared to wild-type indirect flight muscle myosin. Homology models indicate that the surface charge change of the substitution in the highly conversed SH1 region could destabilize the helix, which is critical for the converter domain to rotate to its full range of movement during the power-stroke. This structural change would affect the lever arm swing, resulting in dysfunctional myosin. Given that human IBM-3 is mild in childhood but severe during aging, with the accumulation of inclusion bodies, we are investigating whether inclusion bodies or aggregates appear in aged mutant Drosophila muscle tissues.
Enhancing Patient Safety: A New Movement in Health Care

Interest in patient safety has created a window of opportunity to bring to bear research results on the human contribution to safety and to failure. Given the unique aspects of different health care settings, how can we use this knowledge base to recognize opportunities for and obstacles to progress on patient safety?
Analysis of the Cu-3 Wt pct Ti cellular interphase boundary by various models

The cellular-interlamellar interface in Cu-3 wt pct Ti is modeled employing three different theoretical approaches, which are then compared to experimental observations obtained by transmission electron strain contrast and high-resolution microscopy. The simplest modeling technique used is interfacial superposition, which is shown to give useful information on the general nature of the interface. Van der Merwe’s ideal interfacial-configuration model, which calculates the relative energies of different misorientations and dilatations, establishes three nearby energy minima over azimuthal rotations of less than 1 deg for a given interlamellar habit plane. This is too small a rotation to differentiate by experiment alone. From this ideal interfacial-configuration model, a different orientation relationship than previously reported in the literature is proposed that more closely represents the experimental observations when combined with O-lattice calculations, viz., (111)α ‖ (010)β with [-101]α ‖ [501]β, where α is the fcc matrix, and β is the Cu4Ti orthorhombic phase. Probable defect networks were determined by the O-lattice method for the new and previously proposed orientation relationships (ORs).
A hybrid communication solution to distributed moving query monitoring systems

Location-based services is emerging as an important application area for mobile devices. Mobile users can issue location-based queries to probe their surroundings. The interested objects could be either static, such as gas stations, or moving, such as vehicles. We focus on the moving monitoring queries on moving objects. Due to the continuous nature of the query, existing solutions require the query issuer and the objects to frequently update their locations. This leads to high communication cost. We propose a hybrid solution, which employs two ways of communicating: on-demand access and a broadcast channel. We also design two different indexes: the Grid Index and the Direction Index, to facilitate data retrieval from the broadcast channel. We compare the hybrid solution to an existing distributed solution using simulation and analysis. Our solution achieves 30-60% savings in communication cost. We conclude that the hybrid solution with the is more scalable and desirable for medium-to-large-scale deployments.
Slicing Skew-tableau Frames

Using special decompositions of the frame into zigzag paths, a simple algorithm is given for reducing the enumeration of skew-tableaux to the enumeration of k-tuples of linear partitions. This gives a direct combinatorial method for obtaining the homomorphic image of a frame in the ring Z[x1x2, ...] of polynomials in an infinite sequence of independent indeterminates xi and thus gives a combinatorial interpretation to the non-zero terms that arise from the classical expression for a skew Schur function as a determinant of homogeneous symmetric functions (or of elementary symmetric functions). In the special case of tableau frames, it provides direct combinatorial significance to the signed Kostka numbers of the second kind. Also, skew-tableaux are generalized by defining arena maps, i.e. row monotonic mappings that can fail to be strictly increasing on columns only in specified ways, and the algorithm is extended to include their enumeration.
Air Quality Predictions Using a Fixed Layer-Depth Vertical Structure in the Urban Airshed Model

A model with a varying layer-depth structure tends to have excessive vertical diffusion but can accommodate a well-defined mixing height. It also requires a modified vertical wind field to minimize possible local accumulation or drainage of species mass. A model with a fixed layer-depth structure may require many layers to better resolve the mixing height and contains an explicit challenge to define the thickness of the lowest layer that carries most precursor emission sources. This challenge, also present implicitly in the varying layer-depth case, could be ad dressed only if well-resolved mixing information or the eddy diffusivity profile under realistic physical environments were available, especially at night and in the morning. The impact on air quality predictions of using a fixed layer-depth and a varying layer-depth structure in the Urban Airshed Model is compared. Under the given input information and existing model assumptions, the fixed layer-depth ap proach yields substantially higher hourly c...
WHEN ARE ANEUPLOID CELLS CLINICALLY SIGNIFICANT

Some workers suggest a causal relationship between multiple miscarriages or offspring with trisomy 21 and low frequency hyperdiploidy in the parents. Others consider low frequency aneuploidy of no clinical significance. We compared the frequency of aneuploid cells in five groups of subjects, karyotyped from 1978-83: 79 parents of trisomy 21 patients, 164 other 1st and 2nd degree relatives of Downs patients, 702 subjects with multiple miscarriage, 341 phenotypically and karyotypically normal control parents (e.g., parent of a dysmorphic child or member of a translocation family), and 1,165 others (e.g., chromosomally normal dysmorphic and retarded individual, etc.). In all, 47,595 cells were analyzed from 2,451 subjects. A cell was called hyperdiploid only if the extra chromosome(s) was recognizable and structurally normal.
Genetically Encoded Singlet Oxygen Generator (SOG) Requiring No Exogenous Cofactors

Controlled local photogeneration of singlet oxygen (1O2, the metastable excited state of O2) is useful for generating electron-microscopic contrast, rapidly inactivating proteins of interest, reporting protein proximities over tens of nanometers, and ablating cells by photodynamic damage. The best previous genetically targetable SOG was the biarsenical dye ReAsH bound to tetracysteine motifs, but this system has modest quantum efficiency (0.024), requires antidotes to prevent toxicity, is limited by background staining, and is difficult to extend to intact multicellular organisms. We now report that Arabidopsis phototropin, a blue light photoreceptor containing flavin mononucleotide (FMN) as its chromophore, can be engineered into a small (106-residue) SOG (“miniSOG”), which absorbs maximally at 448 and 473 nm with extinction coefficients of 16,700 and 13,600 M-1cm-1 respectively. Quantum yields for fluorescence and 1O2 generation are 0.30 and 0.47. MiniSOG binds endogenous FMN very tightly (dissociation constant ∼ 10-10 M), so bacteria and mammalian cells upregulate their total FMN to keep miniSOG saturated, without any obvious toxicity in the absence of illumination. Although the green fluorescence of miniSOG is weak and bleachable, it shows that fusions of miniSOG to a variety of proteins in mammalian cells appear to localize correctly, even inside organelles when appropriate. After fixation, illumination of miniSOG to generate 1O2 efficiently polymerizes diaminobenzidine into an osmiophilic deposit, enabling correlative electron microscopy. In an initial biological application, electron microscopy shows that a cell-adhesion molecule, SynCAM1, fused to miniSOG, predominantly localizes to the presynaptic side of cortical neuron synapses. This compact SOG relying only on ubiquitous endogenous FMN will greatly expand the utility of imaging and ablation techniques based on 1O2.
Displacement current and surface flashover

High-voltage vacuum insulator failure is generally due to surface flashover rather than insulator bulk breakdown. Vacuum surface flashover is widely believed to be initiated by a secondary electron emission avalanche along the vacuum-insulator interface. This process requires a physical mechanism to cause secondary electrons emitted from the insulator surface to return to that surface. Here, it is shown that when an insulator is subjected to a fast high-voltage pulse, the magnetic field due to displacement current through the insulator can provide this mechanism. This indicates the importance of the voltage pulse shape, especially the rise time, in the flashover initiation process.
INHERITANCE OF FERTILITY RESTORATION INVOLVING WILD ABORTIVE CYTOPLASMIC MALE STERILITY SYSTEM IN RICE (Oryza sativa L.)

Inheritance of fertility restoration was studied in crosses involving ten elite restorer lines of rice viz. BR6839-41-5-1R, BR7013-62-1-1R, BR7011-37-1-2R, BR10R, BR11R, BR12R, BR13R, BR14R, BR15R and BR16R and one male sterile line Jin23A with WA sources of cytoplasmic male sterility. The segregation pattern for pollen fertility of F 2 and BC 1 populations of crosses involving Jin23A indicated the presence of two independent dominant fertility restoring genes. The mode of action of the two genes varied in different crosses revealing three types of interaction, i.e. epistasis with dominant gene action, epistasis with recessive gene action, and epistasis with incomplete dominance. DOI: http://dx.doi.org/10.3329/bjpbg.v24i1.16997
The Predictive Utility of Conduct Disorder Symptoms in Preschool Children: A 3-Year Follow-Up Study

Conduct disorder (CD) symptoms often emerge during the preschool years, but it is not clear whether they predict later symptoms. The present study examined whether age 3 CD symptoms predict age 6 CD symptoms beyond oppositional defiant disorder (ODD) and attention-deficit/hyperactivity disorder—hyperactive/impulsive (ADHD—HI) symptoms. Participants were 216 preschool children (M Age = 44.19 months), including an externalizing sample (n = 161) and a comparison group (n = 55). Parents were administered a diagnostic interview when children were 3 years old and again 3 years later. The externalizing sample exhibited more CD symptoms than the comparison sample. In the externalizing sample, initial CD symptoms predicted later CD symptoms above and beyond ODD and ADHD HI symptoms; this relation was stronger for boys than for girls. Stealing, property destruction, and fighting independently predicted later CD symptoms. CD symptoms also predicted subsequent ADHD HI symptoms and predicted ODD symptoms at a level that approached significance. Results support the predictive validity of CD symptoms in preschool.
Microstructures of a Ni-9.6 at.% Ta-16.6 at.% Cr alloy after aging up to 1000 hours from 600 to 1,000°C

Abstract The effects of aging of a Ni-rich Ni-Ta-Cr alloy on the microstructure (using optical and scanning electron microscopy) and hardness are presented. In the solution-annealed condition (1280°C, 4 h) the microstructure consisted of a face-centered cubic matrix and about 10% of a Ni 3 Ta type phase, which contained some Cr; the hardness was about 530 DPH. No change in the microstructure nor significant change in hardness occurred upon aging at 600°C for 1,000 h. Aging from 700 to 1000°C produced a significant decrease in hardness, to about 330 DPH after 1000 h. A lamellar product formed, usually initiating at the secondary particles present in the solution-annealed condition. At longer times and higher temperatures, a coarser lamellar product formed. The results of qualitative EDS analysis of the phases are reported.
Further exploration of the object-image metric with image registration in mind

An object-image metric is an extension of standard metrics in that it is constructed for matching and comparing configurations of object features to configurations of image features. For the generalized weak perspective camera, it is invariant to any affine transformation of the object or the image. Recent research in the exploitation of the object-image metric suggests new approaches to Automatic Target Recognition (ATR). This paper explores the object-image metric and its limitations. Through a series of experiments, we specifically seek to understand how the object-image metric could be applied to the image registration problem-an enabling technology for ATR..
Patterning nano-domains with orthogonal functionalities: Solventless synthesis of self-sorting surfaces

Vapor deposited functional polymer thin films can undergo rapid covalent functionalization. Patterning of two functional layers displaying orthogonal reactivity enables sorting of aqueous mixtures of dyes and nanoparticles, such as quantum dots, onto selective areas of nanopatterned surfaces.
CORTICOSTEROIDS IN HUMAN BLOOD. II. FREE AND CONJUGATED 17-HYDROXYCORTICOSTEROIDS IN ESSENTIAL HYPERTENSION.

Metabolism of corticosteroids in hypertension was further investigated. Plasma levels of “free”, “polar free”, glucuronide, and solvolyzable conjugate fractions of 17-hydroxycorticosteroids (17-OH-CS) were estimated by methods recently developed in this laboratory in 17 patients with benign uncomplicated essential hypertension and 60 normotensive control subjects. The results obtained revealed the following statistically significant differences between the 2 groups: 1) levels of 17-OH-CS glucuronides were lower in hypertensives than in normotensives; 2) levels of solvolyzable (presumably sulfate) conjugated 17-OH-CS were higher in hypertensives; 3) the ratio of glucuronides to “sulfates,” which was therefore markedly lower in hypertensives, correlated fairly well (inversely) with the blood pressure of these patients; 4) the ratio of free to solvolyzable steroids in hypertensives was decreased; 5) the ratio of polar free to free 17-OH-CS in hypertensives was increased; 6) preliminary investigation into the...
Investigation of porphyrins and metalloporphyrins by liquid matrix-assisted laser desorption mass spectrometry

Laser desorption mass spectrometry with liquid matrix-assistance has been used to study a series of selected porphyrins and metalloporphyrins. This work presents the results of using a liquid matrix with fibrous material as the substrate for liquid matrix assisted laser desorption of porphyrins and metalloporphyrins. The liquid matrices used for porphyrin studies were o-nitrophenyl octyl ether (NPOE) and 15-crown-5. The use of a liquid matrix with soft laser ionization enhances molecular ion formation. We also have investigated the use of NPOE as a liquid matrix for identifying mixtures of up to six porphyrins in a single shot spectrum without prior separation. The (M + H)+ peak of each metalloporphyrin component in the mixture is clearly indicated in the spectra and no obvious interference effects were observed.
Inadequate visualization and reporting of ventricular function from transthoracic echocardiography after cardiac surgery.

Objectives The purpose of this study was to determine the incidence of and risk factors for inadequate reporting of ventricular function from transthoracic echocardiography after cardiac surgery. Design and Setting A retrospective study of cardiac surgical patients at 1 university hospital. Patients The first 300 consecutive patients who had transthoracic echocardiogram within the first 7 days after cardiac surgery. Interventions None. Measurements and Main Results The primary outcomes for this study were inadequate visualization of the left ventricle, the right ventricle, or both ventricles. Analysis of data from 300 patients identified inadequate imaging of the left ventricle in 50 (17%) cases, inadequate imaging of the right ventricle in 112 (37%) cases, inadequate imaging of both ventricles in 37 (12%) cases, and inadequate imaging of either the left or right ventricle in 125 (42%) cases. Increasing age, earlier postoperative day, male sex, and median sternotomy were associated with inadequate imaging. Conclusions Transthoracic imaging is often inadequate in patients who have undergone recent cardiac surgery. Patient and surgical characteristics influence reporting of right and left ventricular function.
Change in New York's Juvenile Corrections System

From the late 1960s to 1984, the New York State juvenile corrections system has undergone significant change. Following a period of reductions in institutional populations and increases in community-based programs, the state experienced significant growth in the number of secure facilities, the number of youths housed in secure settings, and the total residential population. The purpose of this paper is to describe and document the changing nature of the juvenile system and to focus on the dynamic forces behind the change process. This paper, based on the observations of policymakers active in the juvenile corrections area, points to the importance of several key policy decisions which have fundamentally altered the shape of the residential services component of the juvenile corrections system. Also emphasized is the importance of a wide range of less obvious factors that policymakers have found influential both through their impact on policy decisions and through their direct effect on the system. Consid...
Similarity of isozyme pattern of serum lactate dehydrogenase following treatments with o,o,s-trimethyl phosphorothioate and paraquat

Abstract Oral administration of O,O,S-trimethyl phosphorothioate (OOS-TMP) causes delayed mortality and lung injury in rats. The present study was carried out to determine whether serum lactate dehydrogenase (LDH) activity and its isozyme pattern were capable of detecting lung injury and possible other organ damages caused by OOS-TMP. Carbon tetrachloride (CCl4, 1 ml kg , i.p., 24 h) and paraquat (25 mg kg , i.p., 48 h) were selected as standard chemicals for liver injury, and lung and kidney injuries, respectively. The activity of serum LDH increased to 4 times above control following treatment of rats with OOSTMP (20 mg kg , p.o., 72 h). Treatment with CCU increased the activity to 8 times while paraquat only slightly increased the activity. Isoelectrophoresis of serum samples showed that OOS-TMP increased the activities of isozymes LDH 1 and LDH 2. This isozyme pattern was similar to the pattern of paraquat but quite different from the pattern in animals treated with CCl4, where LDH 5 was most predominant, or in control animals. Thus, the isozyme pattern strongly suggests that OOS-TMP causes the similar organ damage evoked by paraquat, lung and kidney.
Development and evaluation of the Osteoporosis Self-Efficacy Scale.

The Osteoporosis Self-Efficacy Scale was developed as a measure of self-efficacy, or confidence, for behaviors related to physical activity and calcium intake. An item pool of 21 statements, responded to on a visual analog self-report format, was reviewed by a panel of expert judges. The revised item stems were tested with a sample of 201 women, ages 35 to 95. Concurrent data on sport, leisure, and exercise activity and calcium in diet and dietary supplements were collected from the respondents. Factor analysis of responses to the self-efficacy items revealed a logical, theoretically meaningful two-factor structure, one for physical activity and one for calcium intake. Internal consistency estimates for each of the two factors were in the .90s. Convergent and discriminant validity analyses as well as hierarchical regression analyses to explain self-reports of physical activity and calcium intake were supportive. The final version of the brief, psychometrically sound scale contains items reflecting initiation, maintenance, and persistence at osteoporosis preventive behaviors; thus, the Osteoporosis Self-Efficacy Scale is a potentially beneficial research instrument.
Interactions between enkephalin and γ-aminobutyric acid in the larval tiger salamander retina

Abstract Both double-label and intracellular electrophysiological recording techniques were utilized to investigate the interactions between enkephalin and γ-aminobutyric acid in the larval tiger salamander retina.Double-label studies revealed that the vast majority ( 96% ) 96%) of enkephalin-immunostained amacrine cells also exhibit high affinity uptake of [ 3 H]γ-aminobutyric acid. Electrophysiological evidence demonstrated that morphine and γ-aminobutyric acid exert opposite effects on a population of On-Off ganglion cells. γ-Aminobutyric acid decreased the activity of these cells, while enkephalin increased their activity. These findings support the idea that opiate-mediated pathways inhibit GABAergic pathways in the vertebrate retina.
Multivalent Binding and Diffusion of Isolated Kinetochore Particles on Microtubule Lattice in Vitro

The kinetochore is a protein complex that connects spindle microtubules and centromere DNA. During mitosis, kinetochores establish correct bi-oriented attachment of spindle on sister chromatids, and mediate the segregation of sister chromatids in anaphase. Throughout this process, kinetochores remain attached on the plus ends of the microtubules, which undergo rapid depolymerization to effectively pull chromosomes apart. Moreover, kinetochores are able to exert force to the centromere DNA to overcome the viscous drag on the chromosome. How kinetochores harness the energy released from the microtubule depolymerization to do work is under active debate.Recent advances in isolating kinetochore particles enable the possibility to test how kinetochores interact with microtubule in vitro. Using fluorescently labeled kinetochores purified from budding yeast, we are able to observe the dynamic binding, diffusion, pausing, and detachment events of single kinetochore particles on microtubule lattice. Consistent with the stoichiometry knowledge of kinetochore architecture that each kinetochore contains multiple microtubule binding units, the Ndc80 complex, we find that the resident time increases and the diffusion decreases as the number of binding unit increases. The kinetics observation can be explained with a biased-diffusion model, from which the binding and detachment rate, diffusion constant, and pausing rate are extracted. Our observation suggests that biased-diffusion is a plausible mechanism for kinetochore to interact with shrinking microtubule tip. We also show that the binding affinity of kinetochore with microtubule is regulated by the phosphorylation state and the presence of Dam1 complex, as means to establish correct microtubule-kinetochore attachments adopted in vivo.
Urinary retention in sickle cell syndromes

Four patients with sickle cell disease noted the development of urinary retention during an acute painful crisis. The acute urinary retention resolved with improvement in the painful sickle cell crisis. No evidence of anatomic urologic defect, systemic neurologic abnormality, or infection was documented in these patients. Patients with sickle cell disease in painful crisis should be observed for signs of acute urinary retention.
Factors modulating conformational equilibria in large modular proteins: a case study with cobalamin-dependent methionine synthase.

In the course of catalysis or signaling, large multimodular proteins often undergo conformational changes that reposition the modules with respect to one another. The mechanisms that direct the reorganization of modules in these proteins are of considerable importance, but distinguishing alternate conformations is a challenge. Cobalamin-dependent methionine synthase (MetH) is a 136-kDa multimodular enzyme with a cobalamin chromophore; the color of the cobalamin reflects the conformation of the protein. The enzyme contains four modules and catalyzes three different methyl transfer reactions that require different arrangements of these modules. Two of these methyl transfer reactions occur during turnover, when homocysteine is converted to methionine by using a methyl group derived from methyltetrahydrofolate. The third reaction is occasionally required for reactivation of the enzyme and uses S-adenosyl-l-methionine as the methyl donor. The absorbance properties of the cobalamin cofactor have been exploited to assign conformations of the protein and to probe the effect of ligands and mutations on the distribution of conformers. The results imply that the methylcobalamin form of MetH exists as an ensemble of interconverting conformational states. Differential binding of substrates or products alters the distribution of conformers. Furthermore, steric conflicts disfavor conformers that juxtapose a methyl group on substrate with one on methylcobalamin. These results suggest that the methylation state of the cobalamin will influence the distribution of conformers during turnover.
AdaGIDE: a friendly introductory programming environment for a freshman computer science course

We have recently transitioned the programming language in our Introduction to Computer Science course at the U.S. Air Force Academy from Pascal to Ada. Providing an intuitive and straightforward Integrated Development Environment (IDE) for Ada that is suitable for freshman use has been one of our greatest challenges. Although we recognize that a number of Ada IDEs are available, these IDEs do not seem to be designed for beginning programmers. Most of them are either too expensive for students to purchase or are designed for development of large programming projects, carrying significant overhead for the small programs we require in our freshman course. Error messages tend to be fairly complicated, assuming a relatively thorough understanding of the language syntax and semantics. Finally, both commercial and free IDEs can have extensive lead time for bug fix development and are not readily extensible.These concerns led us to develop a Windows 95 Ada IDE that is free to the students, contains the appropriate level of functionality for our freshman course, has a minimal, lead time for bug fix development (since we maintain the code in-house), and can be easily extended to contain additional help for the students. Because we implemented this environment in Ada we can also demonstrate to our students that Ada is applicable to real, large projects, and its usefulness is not limited to the small programs they create in the freshman course. This paper describes our preliminary experience with this environment.The next section briefly describes the IDE and the third section lists a number of issues we have faced trying to interface to Windows 95. The fourth and fifth sections discuss student and faculty reaction to and use of the environment. The final section presents our conclusions and our plans for future enhancements to the IDE.
Identification of the Essential Cysteine and Histidine Residues of the Turnip Yellow Mosaic Virus Protease

Abstract The nonstructural protein expressed from ORF-206 of turnip yellow mosaic virus is proteolytically processed to produce N-terminal 150-kDa and C-terminal 70-kDa proteins. Through the use of linker insertion and deletion analyses coupled to in vitro translation, we have delimited the protease domain to residues 731-885 encoded by the 150-kDa coding region of ORF-206. The effects of substitutions of conserved residues within this region were studied in two assays: a direct assay for proteolysis occurring during in vitro translation and an assay for viral replication in turnip protoplasts. Replication was shown to be dependent on proteolytic maturation by the failure of a mutant with an inactive protease cleavage/recognition site to amplify in protoplasts. Substitutions at Cys 783 and His 869 were the only ones that resulted in undetectable signals in both assays, indicating that these are probable active site residues, most likely of a papain-like protease. Domains putatively encoding similar proteases were detected in the genomes of other tymoviruses and viruses related to tymoviruses. The putative active site cysteine residues of these domains are followed by an aliphatic amino acid, whereas an aromatic amino acid at this position is typical of cellular and previously characterized viral papain-like proteases.
Multiframe phase-diversity algorithm for active imaging

A multiframe phase-diversity algorithm for imaging through the turbulent atmosphere tailored to the statistics of coherent light is developed and presented. The problem is posed as a maximum likelihood estimation where pupil-plane intensity data and atmospheric statistics are used to regularize the inverse problem. Reconstruction results characterized by residual mean square error are presented for varying detection parameters. The resulting algorithm appears to be robust under detection noise processes and results in significant improvement of processed images.
Modulation of mu opioid binding by protein kinase inhibitors

Abstract Several isoquinolinesulfonamide protein kinase inhibitors, including 1-(5-isoquinolinesulfonyl) -2-methylpiperazine dihydrochloride (H7), inhibited [ 3 H]-[ d -Ala 2 ,MePhe 4 , Gly 5 -ol]-enkephalin (DAMGO) binding to rabbit cerebellar mu opioid receptors with K 1 values similar to those reported for kinase inhibition by these compounds, suggesting that their mechanism of action may involve inhibition of protein kinase activity. However, since the binding assays were performed in the absence of exogenous ATP, it is unlikely that protein phosphorylation is taking place during the binding assay, making it improbable that H7 and its congeners inhibit DAMGO binding by inhibition of protein kinase activity. In support of this hypothesis, K252a, a structurally unrelated, broad spectrum, protein kinase inhibitor, was inactive in modulating DAMGO binding, even at a concentration 5-fold greater than its K 1 for inhibiting protein kinase activities. Inhibition of DAMGO binding through inhibition of kinase activity implies a noncompetitive or allosteric mechanism. Scatchard analysis of [ 3 H]DAMGO binding combined with Schild analysis demonstrated that the inhibition of DAMGO binding by the isoquinolinesulfonamides was competitive. These results show that the isoquinolinesulfonamide protein kinase inhibitors directly interact with the mu opioid receptor. Thus, these compounds are unsuitable for the investigation of the potential role of protein phosphorylation in the modulation of mu opioid receptor binding.
The effects of mesoscale structures on the macroscopic momentum equations for two-phase flows

Abstract Mesoscale structures (bubbles, clusters and streamers) in two-phase flows, especially in gas–solid fluidized beds significantly affect macroscopic hydrodynamic behavior. For industrial-scale fluidized beds, it is typically impractical to simulate these structures directly due to the excessive resolution required. To model effects of mesoscale structures, the ensemble phase averaging method is extended to derive macroscopic averaged equations and their closures. It is found that added-mass and drag reduction effects due to mesoscale structures play essential roles in the macroscopic equations of motion. Unlike the classical added-mass force, which is proportional to the continuous fluid density, the mesoscale added-mass force is proportional to the mixture density. Thus for gas–solid systems wherein the classical added-mass force is almost always negligible, the mesoscale added-mass force is, in contrast, found to be quite important. Mesoscale drag reduction results from the fact that, in a particle rich region, there is significantly less relative velocity between particle and fluid phases than indicated by the macroscopic relative velocity. Possible effects of the new force terms in the macroscopic equations are examined from a one-dimensional simulation of a fluidized bed. Significant effects from the new terms on vertical pressure gradient and particle volume fraction distributions are observed.
Relationship between USDA and Japanese beef grades.

Abstract Angus steers ( n = 78) were feedlot-finished to approximately 703 kg live weight. The finished steers were slaughtered at a commercial packing plant, chilled, and evaluated for USDA and Japanese yield and quality-grade characteristics. The resulting carcasses were excessively heavy and fat for the domestic (US) beef industry. Over 70% of the carcasses were US Yield Grade 5, and almost 40% were Japanese Yield Score ‘C’. Although excessively fat externally, fewer than 50% of the carcasses qualified for US Prime, and none of the carcasses qualified for Japanese Meat Quality Score 5. Moderate to high correlations were observed between US twelfth-rib carcass traits and Japanese sixth-rib traits; however, multiple-regression equations based on USDA carcass characteristics explained only 46 and 25% of the observed variation in Japanese marbling score and estimated percentage wholesale-cut yield, respectively.
Constructing the Puerto Rico Self-Concept Scale: Problems and procedures

The Puerto Rico self-concept scale was developed for the purpose of assessing the relationship of self- concept with academic achievement and other school-related variables in Puerto Rico. An 88-item scale that can measure self-concept in the 4th, 7th, and 10th grades was constructed. Empirical criteri on keying was used for the development of items that were also adapted to the phraseology used by local students. After small-group testing, the 264- item bank was administered to 2,445 students. Item analyses focused on item discrimination. Scores showed a low but significant correlation with pre vious' year's grade point average. Overall scale re liability was .93. A 34-item short form had overall reliability of .84. Preliminary norms were prepared from existing data.
Surprising Titanium Complexes Bearing η2-Pyrazolato Ligands: Synthesis, Structure, and Molecular Orbital Studies

As part of a program relating to the preparation of molecular precursors to early transition metal nitride films,2 we have been pursuing the synthesis of complexes that possess only nitrogen ligands in the coordination sphere. Pyrazolato (pz) ligands are particularly attractive nitrogen donors,3 since the ligands themselves are easily prepared and the properties of resultant complexes should be readily modified by appropriate choice of substituents at the carbon atoms. However, application of such complexes as CVD precursors requires monomeric species to achieve the highest possible volatility. Monomeric metal complexes with η2-pz ligands are known for lanthanide and actinide complexes,4,5 but there is only one example of a d-block complex ([Cp2Zr(C3H3N2)(THF)]BPh4) bearing an η2-pz ligand.6 All other structurally characterized d-block metal complexes have shown the ligand to be present either in the bridging mode or with only one nitrogen atom coordinated to the metal.7 With these considerations in mind, we report the synthesis and characterization of several homoleptic pz complexes of titanium(IV). These species are the first homoleptic monomeric pz complexes of any metal and contain exclusively η2-pz ligands. The results of molecular orbital calculations rationalize why the η2-bonding mode is preferred and suggest that η2-pz complexes should be common in early to middle transition metals. Treatment of tetrakis(dimethylamido)titanium(IV) with 4 equiv of 3,5-dimethylpyrazole8 or 3,5-diphenylpyrazole8 in refluxing toluene afforded tetrakis(3,5-dimethylpyrazolato)titanium(IV) (1; 83%) and tetrakis(3,5-diphenylpyrazolato)titanium(IV) (2; 76%) as yellow and light red solids, respectively (eq 1).9 Compounds 1 and 2 were characterized by spectro-
The effect of hypotensive anesthesia on renal hemodynamics.

Abstract Deliberate hypotensive anesthesia (MBP = 36 mm Hg) using Halothane, hyperventilation, and positive pressure respiration (peak inspiratory pressure = 15 cm H 2 O) was used in 7 dogs for a 2-hr period. Xenon-133 washout was employed by injection of 800–1500 μCi through a catheter placed under fluoroscopic control in the right renal artery. Washout curves were obtained before hypotensive anesthesia, during and after a return of normal hemodynamics using a collimater placed over the right flank. The curves were analyzed and total renal blood flow plus four components of renal blood flow were developed: I cortex; II juxtamedulla; III inner medulla; and IV hilar fat. Using an indocyanine green indicator dilution curve, cardiac output was measured. Urinary output was collected and blood gases monitored. Total renal blood flow decreased significantly during hypotensive anesthesia only to return toward normal within 30 min of discontinuing deliberate hypotension (328 control → 159 during hypotensive anesthesia → 227 ml/100 g/min after hypotensive anesthesia). This decrease in renal blood flow was associated with a fall in cardiac output which also returned toward normal promptly after discontinuing inhalation anesthesia (3.2 → 1.7 → 3.0 liter/min). The ratio of renal blood flow/cardiac output did not change with hypotensive anesthesia indicating an absence of renal vasoconstriction, and renal vascular resistance actually fell from .427 to .306 mm Hg/ml/100 g/min. During the recovery phase, because the blood pressure and cardiac output returned to the control level before renal blood flow, the ratio of renal blood flow/cardiac output fell from 7.1 to 4.9% and the renal vascular resistance rose from .306 to .611 mm Hg/ ml/100 g/min. It was apparent that during recovery renal vasoconstriction developed. The fall in renal blood flow with hypotensive anesthesia was associated with a significant fall in Component I (cortical) flow (414 → 257 → 330 ml/100 g/min) but no significant change in Component II (outer medullary) flow (72 → 74 → 98 ml/ 100 g/min) or the percent distribution of radioactivity between cortex and medulla. This indicates a selective decrease in cortical flow and an absence of marked intrarenal shunting which is seen with hypovolemic hypotension. Urine output fell during hypotension (65 → 20 → 80 ml/hr) but did not cease entirely in any animal. The explanation for the known renal safety of hypotensive anesthesia rests primarily with the absence on intrarenal shunting and associated vasoconstriction during hypotension.
Abstinence effects and reactivity to nicotine during 11 days of smoking deprivation

The purpose of the present study was to investigate smoking abstinence effects and the dissipation of tolerance (reactivity to nicotine) under controlled laboratory conditions. Seventeen male and female regular smokers were tested first in a session following ad libitum smoking and then in an additional five sessions over the course of 11 days during which they abstained from smoking. A metered dose of nicotine was administered via intranasal spray to ensure standard exposure, and pre- and post-dosing measures of heart rate, blood pressure, cortisol, galvanic skin response (GSR), craving, and several DSM-IV withdrawal symptoms (anxiety, irritability, restlessness, difficulty concentrating, and appetite) were collected. Prior to the nicotine test dose during deprivation sessions, heart rate and systolic blood pressure evinced elements of both an 'offset abstinence pattern' (deflection in a direction opposite to that produced by smoking) and a 'transient abstinence pattern' (deflection followed by a subsequent return); for cortisol, an offset pattern was observed, whereas for GSR and craving, a transient pattern was found. With respect to loss of tolerance, heart rate reactivity was found to increase significantly after 2 days' abstinence from nicotine, and the increase was sustained in subsequent sessions. Cortisol reactivity revealed more gradual dissipation, with significant differences evident only after 9 days of abstinence. These findings extend research on nicotine abstinence effects and on the dissipation of tolerance to nicotine deprivation intervals of nearly 2 weeks and confirm prior observations of variability across different response systems.