cssi/SciSciGPT-SciSciNet huggingface dataset:
Four dimensional magnetic resonance imaging with retrospective k-space reordering: a feasibility study.

Purpose: Current four dimensional magnetic resonance imaging (4D-MRI) techniques lack sufficient temporal/spatial resolution and consistent tumor contrast. To overcome these limitations, this study presents the development and initial evaluation of a new strategy for 4D-MRI which is based on retrospective k-space reordering. Methods: We simulated a k-space reordered 4D-MRI on a 4D digital extended cardiac-torso (XCAT) human phantom. A 2D echo planar imaging MRI sequence [frame rate (F) = 0.448 Hz; image resolution (R) = 256 × 256; number of k-space segments (N KS) = 4] with sequential image acquisition mode was assumed for the simulation. Image quality of the simulated “4D-MRI” acquired from the XCAT phantom was qualitatively evaluated, and tumor motion trajectories were compared to input signals. In particular, mean absolute amplitude differences (D) and cross correlation coefficients (CC) were calculated. Furthermore, to evaluate the data sufficient condition for the new 4D-MRI technique, a comprehensive simulation study was performed using 30 cancer patients’ respiratory profiles to study the relationships between data completeness (Cp ) and a number of impacting factors: the number of repeated scans (NR ), number of slices (NS ), number of respiratory phase bins (NP ), N KS, F, R, and initial respiratory phase at image acquisition (P 0). As a proof-of-concept, we implemented the proposed k-space reordering 4D-MRI technique on a T2-weighted fast spin echo MR sequence and tested it on a healthy volunteer. Results: The simulated 4D-MRI acquired from the XCAT phantom matched closely to the original XCAT images. Tumor motion trajectories measured from the simulated 4D-MRI matched well with input signals (D = 0.83 and 0.83 mm, and CC = 0.998 and 0.992 in superior–inferior and anterior–posterior directions, respectively). The relationship between Cp and NR was found best represented by an exponential function ( C P = 100 1 − e − 0 . 18 N R , when NS = 30, NP = 6). At a CP value of 95%, the relative error in tumor volume was 0.66%, indicating that NR at a CP value of 95% (N R,95%) is sufficient. It was found that N R,95% is approximately linearly proportional to NP (r = 0.99), and nearly independent of all other factors. The 4D-MRI images of the healthy volunteer clearly demonstrated respiratory motion in the diaphragm region with minimal motion induced noise or aliasing. Conclusions: It is feasible to generate respiratory correlated 4D-MRI by retrospectively reordering k-space based on respiratory phase. This new technology may lead to the next generation 4D-MRI with high spatiotemporal resolution and optimal tumor contrast, holding great promises to improve the motion management in radiotherapy of mobile cancers.
Density Correlations between Solar wind and Pick-up Ions

Interstellar pick‐up ion and solar wind spectra were measured with New Horizons/SWAP between 11 and 12 AU. We report on detailed fitting of these spectra. To perform the fitting, we have constructed an empirical model that includes interstellar pick‐up ions as well as solar wind H+, solar wind He2+, and solar wind O6+. A fifth population is needed to complete the fitting; we use inner source pick‐up protons. We find a correlation between the densities of the solar wind H+, and all other populations. The two strongest correlations are with the interstellar pick‐up ions and the inner source pick‐up ions. We discuss the correlation between solar wind and interstellar pick‐up ion densities.
Process and Outcome of Rehabilitation of Homeless Veterans and Their Relationship with Personality Style

Abstract Treatment process and outcome data for 225 consecutive admissions to a rehabilitation program for the homeless were reviewed. The Northeast Program Evaluation Center's criteria were employed to evaluate participation and outcome (e.g., general, employment, and housing) for participants. Significant relationships were found between predominant personality features and degree of participation in program and living arrangements at discharge.
Phosphorus stress effects on growth and seed yield responses of nonnodulated soybean to elevated carbon dioxide

The influence of P availability on plant responses to elevated atmospheric CO concentrations has received limited research attention. Therefore, an experiment was conducted to examine the effect of a wide range of P availabilities on plant response to enriched atmospheric CO. Nonnodulating soybean [ (L.) Merr., ‘Lee’] plants were grown from germination to maturity in controlled environment chambers at 350 or 700 μL L CO and supplied with a complete nutrient solution containing either 0.005, 0.10, 0.25, 0.50, or 1.00 m P. Growth and seed yield were maximized at the 0.25 and 0.50 m P concentrations at 350 and 700 μL L CO, respectively. Growth and yield were significantly increased by CO enrichment at all except the lowest P concentration. The stimulation of growth at high CO was consistently associated with increased leaf area, net assimilation rate, P uptake, and P utilization efficiency in the production of dry matter. When averaged over the four highest P levels, total root mass was increased 63% by CO enrichment, but P uptake efficiency per unit root mass was decreased 22%. The yield enhancement of 23 to 57% at high CO was associated with increases in the number and size of seed. Carbon dioxide enrichment had no significant effect on harvest index. The results indicate that CO enrichment can result in stimulation of growth and yield of nonnodulated, NO-fed soybean plants, even at concentrations of P that limit plant growth at ambient CO concentrations.
No-chaos criteria for certain jerky dynamics

Abstract Autonomous third-order scalar differential equations or jerky dynamics given by x +Aẍ+Bẋ=g(x) are known to constitute an elementary class of dynamical systems that can exhibit chaotic behavior if the nonlinearity g(x), the entering control parameters and the initial conditions are appropriately chosen. We investigate conditions on g(x) and the control parameters that are necessary for the appearance of chaotic behavior in these equations by deriving several analytical criteria that exclude chaotic long-time solutions.
Sequestered calcium triggers oocyte maturation in Chaetopterus

Abstract In order to test the involvement of Ca 2+ in maturation and activation of eggs, we have treated Chaetopterus eggs with ionophore A23187 and quercetin, an inhibitor of Ca 2+ -dependent ATPase. Ionophore A23187 induced rapid germinal vesicle breakdown (GVBD) and activated eggs as evidenced by fertilization envelope elevation at a wide range of concentrations. Higher concentrations of A23187 induced GVBD in Ca 2+ -free artificial sea water, demonstrating the independence of GVBD in Chaetopterus from external Ca 2+ . At high concentrations of ionophore, eggs became ameboid and underwent the initial phases of differentiation without cleavage. Low concentrations of quercetin induced GVBD with or without external Ca 2+ . This treatment did not activate eggs, but allowed them to be fertilized and undergo some development. The results of these experiments indicate 1) that Ca 2+ fluxes regulate GVBD and activation in Chaetopterus , 2) that these fluxes can be internally generated, and 3) that Ca 2+ sequestration by Ca 2+ -dependent ATPase may have a role in maintaining the intact germinal vesicle.
Analysis of the effects of multirate filters on stationary random inputs, with application in adaptive filtering

The authors study the statistical properties of the outputs of some basic multirate filtering operations when the input is a wide-sense-stationary (WSS) or a cyclo-WSS (CWSS) process. They give necessary and sufficient conditions under which the output remains WSS or CWSS. For some multirate filters, the output response to a WS input is CWSS. Expressions for the periods of cyclostationarity for such cases are given. As an application of the theory, the optimal (Wiener) solution for a new efficient multirate adaptive filtering method suitable for identification of bandlimited channels is derived. It is shown that the optimal (Wiener) filter is a linear periodically time-varying (LPTV) filter. Simulations are included which verify that an LPTV adaptive filtering structure gives better performance than a transversal adaptive filtering structure. >
On the importance of temporal dynamics in modeling urban activity

The vast amount of available spatio-temporal data of human activities and mobility has given raise to the rapidly emerging field of urban computing/informatics. Central to the latter is understanding the dynamics of the activities that take place in an urban area (e.g., a city). This can significantly enhance functionalities such as resource and service allocation within a city. Existing literature has paid a lot of attention on spatial dynamics, with the temporal ones often being neglected and left out. However, this can lead to non-negligible implications. For instance, while two areas can appear to exhibit similar activity when the latter is aggregated in time, they can be significantly different when introducing the temporal dimension. Furthermore, even when considering a specific area X alone, the transitions of the activity that takes place within X are important themselves. Using data from the most prevalent location-based social network (LBSN for short), Foursquare, we analyze the temporal dynamics of activities in New York City and San Francisco. Our results clearly show that considering the temporal dimension provides us with a different and more detailed description of urban dynamics. We envision this study to lead to more careful and detailed consideration of the temporal dynamics when analyzing urban activities.
The Most Critical Issue Facing the ASA

The ASA worries that it may be allowing organizational fragmentation to contribute to intellectual disarray in the discipline. ASA should recognize that the increase in the number of sociologists has made it easier to start new, economically viable organizations, with their own journals, prizes, and meetings. A serious problem facing ASA is that the American Sociological Review shows an editorial bias toward quantitative research. Sociologists need to strengthen alternative organizations-regional and specialty-especially among groups which differ politically from ASA, so that it will not try to speak for all of us.
Effect of Uridine Diphospho‐N‐acetylglucosamine and Sodium Salicylate on L‐Glutamine‐D‐Fructose-6-phosphaAtme inotransferase Activity from Rat Gastric Mucosa

Mechanisms of inhibitory action of sodium salicylate on L‐glutamine‐D‐fructose‐6‐phosphate aminotransferase, prepared from rat gastric mucosa, were studied. Sodium salicylate at lower concentrations (10–20 mM) inhibited reversibly aminotransferase activity by competing with fructose‐6‐phosphate. At higher concentrations, sodium salicylate inactivated the enzyme irreversibly, with an inactivation rate following first‐order kinetics with respect to the enzyme concentration. Uridine‐5′‐diphospho‐N‐acetylglucosamine is an endogenous feedback inhibitor. It inhibited the aminotransferase‐catalyzed reaction also by competing with fructose‐6‐phosphate but with an inhibiting activity 1000 times that of sodium salicylate. Uridine‐5′‐diphospho‐N‐acetylglucosamine reduced the salicylate inhibition of the enzymic reaction and protected the enzyme from salicylate‐induced irreversible inactivation. At a fixed concentration of uridine‐5′‐diphospho‐N‐acetylglucosamine (7 × 10−6 M), an increase of salicylate concentration produced an increase in enzyme activity as compared with the control.
Biological externalities and evolution: A comment

Abstract Tullock's illuminating article in this Journal (1971) uses the economic theory of externality to anlyze the natural equilibira of biological systems where species interact. He demonstrates that the natural system does not attain a Pareto optimum—that it would be possible to increase both species (in a two-species model) by appropriate management. In this comment on his paper, his analysis is shown to result from implicit restrictions on further evolution which would be relevant to the external interaction. If evolution is allowed to proceed costlessly to internalize the externality, natural processes are shown to lead to optimality. Further, the directions of future evolution may be predicted from the analysis of biological externalities. The extension of Tullock's model to analyze further evolution is shown to be analogous to certain extensions of the standard model of economic externalities.
Counselor perceptions of organizational factors and innovations training experiences

Because work environment is central to understanding job performance, drug counselor perceptions of their programs and their skills were examined in relation to their attitudes about innovations training and its utilization. Latent profile analysis of measures on organizational climate and staff attributes for 1047 counselors from 345 programs defined three categories of counselors-labeled as isolated, integrated, and exceptional. All had generally positive views of their professional skills, although the isolated group scored lower on scales representing professional growth and influence on peers. They were less positive about the "climate" of programs in which they worked and were higher on stress. Program resources predicted the counselor groups, with the isolated having more limited resources. Counselor categorizations also differed in terms of workshop training experiences, with the isolated group of counselors reporting significantly less exposure, satisfaction, and program-wide use of workshop training.
Modulation of cellular immune function in vitro by histamine receptor-bearing lymphocytes: mechanism of action.

When soluble histamine is added to guinea pig lymphocytes in vitro, antigen-induced cellular proliferation and the production of migration inhibitory factor is suppressed. The inhibitory effects that are produced by histamine have been shown to be mediated by the histamine-type 2 receptors of the involved cells, but the exact nature of this suppression has not been fully explored. The present studies have evaluated, following immunization, the effect of histamine on macrophage function in vitro, and affinity chromatography to delete a subpopulation of cells bearing histamine receptors. When we treated monolayers of peritoneal exudate cells with histamine (up to 10−3 M) we found that histamine did not interfere with antigen binding by macrophages, macro phage presentation of antigen to lymphocytes, nor the antigen-independent or antigen-dependent lymphocyte-macrophage rosetting. Columns containing insolubilized conjugates of histamine and rabbit serum albumin depleted a subpopulation of cells responsive to histamine i.e., the non-adherent cells made migration inhibitory factor and proliferated in the presence of histamine. The latter finding suggested that the retained cells might have suppressor function and if so, might mediate their effect through the release of a soluble factor. Preliminary data obtained in these studies supports this hypothesis. We conclude that cells bearing histamine receptors may serve a regulatory role in cellular immunity after their activation by histamine by producing a non-dialyzable factor with immunosuppressive properties.
If ecological risk assessment is the answer, what is the question?

Abstract Ecological risk assessment has become a commonly used tool in policy analysis, but its use is controversial. Opinions are diverse; they range from enthusiastic support to caustic dismissal. Much of the controversy with using risk assessment in ecological policy analysis revolves around defining the initial policy question or problem to be assessed. In formulating the “question”; in ecological risk assessment, the nature of the analytical technique forces analysts to make assumptions of values and priorities; these assumptions may not be the same as those of the public or their elected or appointed representatives. Specifically, much of the difficulty with applying risk assessment is that, by definition, risk is adverse. Deciding which ecological changes are adverse (undesired) and which are beneficial (desired) is likely to be the primary political debate. Ecological conditions and changes are classified by the values and priorities of the person or administrative body doing the classification; e...
Synergistic inhibition of metabolic cooperation by oleic acid or 12-0-tetradecanoylphorbol-13-acetate and dichlorodiphenyltrichlorethane (DDT) in Chinese hamster V79 cells: Implication of a role for protein kinase C in the regulation of gap junctional intercellular communication

The effects of TPA and/or DDT and oleic acid and/or DDT on gap junction-mediated intercellular communication (i.e. metabolic cooperation) between Chinese hamster V79 cells was examined. Addition of TPA, DDT or oleic acid alone to cocultures of 6t-hioguanine-resistant (6-TG R ) and 6-thioguanine-sensitive (6-TG S ) V79 cells significantly increased the recovery of 6-TG R cells indicating inhibition of metabolic cooperation. In the presence of TPA and DDT or oleic acid and DDT the observed recovery of 6-TG R cells was significantly greater than the expected (calculated) additive 6-TG R cell recovery. No synergistic increases in 6-TG R cell recovery were observed when co-cultures of V79 cells were exposed to dieldrin and DDT. These results indicate that TPA and DDT or oleic acid and DDT can act synergistically to inhibit metabolic cooperation. These data suggest a role for protein kinase C in the regulation of gap junction-mediated intercellular communication.
Increased Dietary Vitamin D Suppresses MAPK Signaling, Colitis, and Colon Cancer

Epidemiologic studies associate low serum vitamin D levels with an increased risk of colon cancer and inflammatory diseases such as inflammatory bowel disease (IBD). 129-Smad3tm1Par/J (Smad3−/−) mice are a model of bacteria-driven colitis and colon cancer when infected with Helicobacter bilis (H. bilis). Thus, we used this mouse model to determine whether increased dietary vitamin D would reduce inflammation and colon cancer. Smad3−/− mice were fed purified diet with either maintenance (1 IU vitamin D/g diet; maintenance) or increased concentrations of vitamin D (5 IU vitamin D/g diet; high vitamin D). One week after diet initiation, mice were inoculated with broth or H. bilis and were necropsied at several time points postinoculation to assess inflammation, dysplasia, and neoplasia incidence. At 16 weeks postinfection, 11% of mice fed high vitamin D diet had cancer compared with 41% of mice fed maintenance diet (P = 0.0121). Evaluation at an early time point (1 week postinfection) showed that animals fed high vitamin D had decreased MAPK (p-P38 and p-JNK) activation in lamina propria leukocytes as well as decreased NFκB activation in colonic epithelial cells. Reduction in MAPK and NFκB activation correlated with decreased IBD scores (2.7 vs. 15.5; P
Masing behavior observed in monocrystalline copper during cyclic deformation

Abstract Masing behavior in monocrystalline copper was investigated with the multi-step test method, mainly for amplitudes corresponding to the plateau of the cyclic stress-strain curve. Hysteresis loops were analyzed in terms of friction stress and back stress. It was found that Masing behavior is not a saturation phenomenon, but simply requires that no changes occur in dislocation structure under variable loading. Dislocation structure developed at a higher strain level was found to remain relatively stable when cycling at lower strain levels provided that cycling is short. Masing behavior was therefore observed for step tests where there had been previous cycling at higher strain amplitude. On prolonged cycling, the dislocation structure would change gradually. The conclusion that Masing behaviour depends on constancy of the dislocation structure supports that obtained from polycrystalline material.
Isolation and preliminary characteristics of β‐N‐acetylglucosaminidase in the sperm of Siberian sturgeon (Acipenser baerii) and rainbow trout (Oncorhynchus mykiss)

Summary The aim of this study was to characterize the enzyme β-N-acetyglucosaminidase (β-NAGase) in the milt and spermatozoa extracts from Siberian sturgeon and rainbow trout. After ion exchange chromatography one protein peak showed β-NAGase activity in sturgeon milt plasma and sperm extracts of both species. Surprisingly, two protein peaks showing β-NAGase activity were found in rainbow trout milt plasma. The molecular mass of β-NAGase was estimated by gel filtration as 127 kDa for rainbow trout spermatozoa, 271 kDa for sturgeon spermatozoa, and 74 kDa for milt plasma from both species. The kinetic parameters were determined for milt plasma and sperm extracts. The optimum pH of the β-NAGases was 3.8 for sturgeon milt plasma, 4.4 for sturgeon sperm extract, and 4.4–4.8 for milt plasma and sperm extract from rainbow trout. Km value of the β-NAGases was 0.212, 0.563, 0.779 mm for sturgeon milt plasma, sturgeon sperm extract or rainbow trout extract, respectively. The β-NAGase from sperm extracts in both species showed 100% activity even after incubation at 56°C by 20 min, whereas its activity was decreased to 23% in sturgeon milt plasma and to 2% in trout milt plasma.
Detection of viable Vibrio cholerae by reverse-transcriptase polymerase chain reaction (RT-PCR)

The use of conventional PCR can amplify target DNA from both viable and nonviable cells ofVibrio cholera. Detection of only viable microbial pathogens in biological samples, especially clinical and food samples, is usually desired to ensure positive test results are associated with active agents, and not the remains of dead cells. Positive identifications caused by nonliving causative agents may lead to misguided decisions concerning the effectiveness of treatment, and whether patient treatment should be continued or whether the food should be discarded. Consequently, this work was directed toward development of a reverse-transcriptase polymerase chain reaction (RT-PCR)-based in vitro DNA amplification method, which specifically detects only viable cells. Total RNA from both viable and nonviable cells was purified by using a FastPrep Cell Disrupter (√Bio 101/Savant) and FastRNA extraction reagents (√Bio 101). The purified RNA was treated with DNase I (RNase-free) to avoid any amplification from the contaminating target DNA. An RT-PCR approach using this rapid and effective method for RNA purification showed amplification of the target mRNA only from the viable cells. The sensitivity of detection of viable cells ofV. cholerae was ≥103, which is well within the minimum number of cells (105–106) required for infection. The use of a reliable prokaryotic RNA extraction, method followed by RT-PCR amplification of the target mRNA can be used for specific detection of viable microbial pathogen, such asV. cholerae.
Die Verantwortung der Wirtschaftsinformatik für die Finanzmarktkrise

Entscheidungsunterstutzungssysteme (EUS) zahlen zu den zahlreichen Errungenschaften der Wirtschaftsinformatik. Diese speziellen Anwendungssysteme unterstutzen Fuhrungskrafte aus dem mittleren und oberen Management bei Entscheidungsprozessen durch die Bereitstellung relevanter Informationen und die Generierung von Handlungsempfehlungen auf der Basis von Entscheidungsmodellen. Auch bei der Entstehung und Entwicklung der seit Juli 2007 vorherrschenden Finanzmarktkrise spielen diese eine Rolle. So stutzen sich nahezu alle Marktakteure bspw. im Rahmen des Risikomanagements auf entsprechende Modelle und Anwendungssysteme. Vor diesem Hintergrund mochte dieser Beitrag die Rolle und Verantwortung der Wirtschaftsinformatik diskutieren sowie Lehren aus der Finanzmarktkrise fur die IT-basierte Entscheidungsunterstutzung ziehen.
Computational Issues in Modeling Ion Transport in Biological Channels: Self-Consistent Particle-Based Simulations

In this work, a self-consistent Langevin dynamics simulator will be presented, and computational issues unique to the simulation of charge transport through ion channels will be addressed. The simulation approach is divided into two parts; the first is the development of an efficient model to account for the charge transport in bulk electrolyte solutions, while the second is the accurate representation of the channel protein and lipid structure. A cavity is made in the interior of a phospholipid bilayer and an ion channel is inserted, where the atomic coordinates of the protein are obtained from experimental work. The electrostatic potential felt by a potassium ion along the center of the channel is then calculated and comparisons are made between two types of potassium channels, KcsA and MthK.
Modeling and Analysis of Standby Redundant Computing Systems

In this paper, we have developed performance models to represent the fault-tolerant characteristics of standby redundant computing systems. These models have the advantage of being quite general and are useful to study the performance characteristics under any arbitrary life time distribution for the components of the system. For the proposed models, we have derived expressions for three performance metrics for these systems.
OS057. Pathophysiological role of elevated tissue transglutaminase in autoantibody-induced features of preeclampsia in pregnant mice.

Introduction Preeclampsia (PE) is highly associated with the presence of autoantibodies that activate the major angiotensin receptor, AT1R. These autoantibodies (termed AT1-AA) cause most features of PE when introduced into pregnant mice and are believed to contribute to disease pathogenesis. Tissue transglutaminase (tTG) is a prominent member of a family of enzymes that crosslink proteins by catalyzing the formation of an isopeptide bond between the amide group of glutamine and the free amino group of lysine and is believed to play a role in AT1R activation. Objectives To test the hypothesis that tTG plays a role in autoantibody-mediated AT1R activation and thereby contributes to the pathophyhsiology of PE. Methods Western blotting was used to quantify tTG in placentas of normotensive pregnant women and those with PE. Immunohistochemistry was used to determine cellular localization of tTG, AT1R and glutamyl-lysine isopeptides in placenta tissue. Co-immunoprecipitation experiments were used to explore the possible association of tTG and AT1R. Finally, in an effort to determine the role of tTG in AT1-AA-induced features of PE in vivo, we treated autoantibody-injected pregnant mice with cystamine, a potent tTG inhibitor. Results Western blot analysis showed elevated tTG in placentas of women with PE. Immunohistochemical analysis revealed that increased levels of tTG, glutamyl- lysine isopeptides, AT1R co-localized in the microvillous membrane of PE placentas. Immunoprecipitation of tTG from human trophoblast cell (HTR) lysates resulted in the co-immunoprecipitation of AT1R, thereby providing evidence for an interaction between tTG and AT1R in HTR cells. Finally, we found that cystamine treatment significantly attenuated key features associated with PE including hypertension and proteinuria in the PE-IgG-injected pregnant mice. Conclusion Taken together, we identified a previously unrecognized role of elevated tTG in PE likely by activating or stabilizing AT1Rs. These studies provide novel mechanisms of autoantibody-induced AT1R activation by elevated placental tTG, highlight the role of tTG in the pathogenesis of PE and suggest novel therapeutic strategies for the disease.
Optical lattice clocks: Keeping time in three dimensions

The demonstration of an optical clock in which individual atoms are confined in a three-dimensional optical lattice moves us closer to the atomic clockmaker's dream: tens of thousands of isolated atoms that work in parallel.
Short-circuit currents and recovery voltages

FIELD tests were made on a 7,200/12,470Y-volt multigrounded rural distribution system to check fault current calculations and to investigate transient recovery voltages experienced as a consequence of clearing fault currents. Tests were also made using a miniature circuit representation of a rural distribution system in order to investigate the effect of variations in circuit conditions incident to the fault. The use of the miniature system or transient analyzer made possible a determination of the order of magnitude of crest voltages and rates of rise that may be expected under most severe conditions. The work is expected to be of considerable value in the preparation of standards for the testing of such devices as expulsion lightning arresters and distribution fuse cutouts. In so far as the authors are aware, this is the first published information on transient recovery voltage tests on rural distribution systems and the correlation therewith of transient analyzer results.
Drf1-dependent Kinase Interacts with Claspin through a Conserved Protein Motif

The Dbf4/Drf1-dependent kinase (DDK) is required for the initiation of DNA replication in eukaryotes. Another protein, Claspin, mediates the activation of a cellular checkpoint response to stalled replication forks and is also a regulator of replication. In this study, we found that DDK phosphorylates Claspin in vitro and forms a nuclear complex containing Cdc7, Drf1, and Claspin in Xenopus egg extracts. In addition, purified Claspin and DDK are capable of a direct in vitro interaction. We identified a conserved binding site on Claspin required for its interaction with DDK. This site corresponds to the first of two sequence repeats in the Chk1-binding domain of Claspin. Furthermore, we have established that two amino acids in this motif, Asp861 and Gln866, are essential for the interaction between Claspin and DDK. We found that mutant forms of Claspin incapable of interacting with DDK are still able to associate with and activate Chk1 in response to DNA replication blockages. However, Claspin-depleted egg extracts that have been reconstituted with these mutants of Claspin undergo DNA replication more slowly. These findings suggest that the interaction of DDK with Claspin mediates a checkpoint-independent function of Claspin related to DNA replication.
Alpha2-adrenoceptor antagonists and male sexual behavior: I. Mating behavior

Abstract Three α 2 -adrenoceptor antagonists yohimbine, idazoxan, and imiloxan were compared by examining the effects of a single injection on male rat copulatory behavior. Dose ranges were: yohimbine: 0.25–8.0 mg/kg; idazoxan: 0.25–8.0 mg/kg; imiloxan: 12.5–50.0 mg/kg. Yohimbine and idazoxan administration produced significant increases in the number of animals copulating to ejaculation and all three drugs increased the rate of copulation as evidenced by reductions in ejaculation latency and intercopulatory interval. Only yohimbine significantly reduced mount latency and postejaculatory interval, but yohimbine and imiloxan significantly reduced intromission latency and idazoxan showed a similar trend. The highest yohimbine dose suppressed sexual activity. A time-course experiment with yohimbine (2.0 mg/kg) and idazoxan (4.0 mg/kg) showed stimulation at 75 min and a trend at 5. To further explore the arousal-stimulating capacity of the two more effective drugs, a mounting test with genital anesthetization was used. Yohimbine but not idazoxan showed marked increases in mounting at 1.0–4.0 mg/kg. Both drugs had a suppressive effect at the highest doses. These data support the involvement of α 2 -adrenoceptors in the regulation of male sexual behavior, specifically by facilitating sexual arousal, with no effects on ejaculatory threshold, as measured by intromission frequency. Yohimbine is the most globally effective agent and it is likely that factors other than yohimbine's α 2 -antagonism may play a role in its unique, consistent and broad behavioral effects.
Simultaneous determinations of alpha-emitting isotopes of uranium and plutonium in bone

A radiochemical procedure has been developed for the simultaneous determinations of alpha-emitting isotopes of uranium and plutonium in bovine bone. The radiochemical recoveries ranged from 61 to 93% with a mean of 80±10% for uranium and 57 to 88% with a mean of 75±11% for plutonium. The method was successfully used for human bone.
Rate assay for estimation of thiol affinity of sulfhydryl-reactive agents: Estimation of SH-reactivity

An interaction between cysteine SH groups and β- nitrostyrene was suggested from alterations in the ultraviolet spectrum of β-nitrostyrene following the addition of cysteine, but not serine. In the presence of β-nitrostyrene or phenylmercuric chloride, the rate of color development resulting from the reaction of cysteine and DTNB was reduced; increasing the concentration of β-nitro- styrene resulted in increased interference in the color development. Excess DTNB did not mitigate the influence of β-nitrostyrene on color development; however, excess cysteine was found to overcome the effects of the β-nitrostyrene on the development of color. The implication of this interference on single point SH content determinations is discussed. Application of inhibition of the cysteine DTNB reaction to estimate SH-reactivity of thiol-reactive agents is described.
The clinical nurse leader: a response from practice

In October 2003, over 200 nurse leaders from education and practice met at the invitation of the American Association of Colleges of Nursing. A newly released white paper, describing the role of the clinical nurse leader, was discussed at the conference. This article outlines a response to that white paper from one practice setting. The article shares information about another role, that of team coordinator, that is similar to clinical nurse leader and has been implemented at an integrated not-for-profit health care system in 5 hospitals. The comparison of the team coordinator role to the clinical nurse leader role might assist in visualizing such a role in practice. Although the roles are not identical, many of the driving forces for change were similar; these included the need to meet the changing demands for improved patient outcomes and nurse retention. The team coordinator role has 4 domains of practice that are crosswalked against the clinical nurse leader 15 core competencies. An evaluation of the team coordinator role showed changes that need to be made, such as placing more emphasis on clinical progression of patients. Lessons learned are shared, including keeping the scope of the role manageable, providing documentation standards for new roles, and the leadership required of the nursing executive to implement change.
Pattern of polynuclear aromatic hydrocarbons in indoor air: Exploratory principal component analysis

Principal component analysis (PCA) was used to study polynuclear aromatic hydrocarbon (PAH) profiles in indoor air. Fifteen PAHs were measured in ten different homes in Columbus (Ohio) which had different indoor emission characteristics such as gas utilities, wood-burning fireplaces, and cigarette smokers. Different PAH concentration patterns emerged depending upon the emission sources present in the different homes. Of these, cigarette smoking appeared to have the greatest impact on the indoor PAH concentrations. The PCA allowed convenient displays of the multidimensional data set from which the PAH concentration characteristics could be elucidated. The interrelationship between the different PAHs was also studied by correlation analysis.
Temperature-Dependent Infrared Absorption Cross Sections of Methyl Cyanide (Acetonitrile)

Abstract Pressure broadened (1 atm. N 2 ) absorption cross sections and integrated band intensities have been derived from laboratory spectra of CH 3 CN , recorded at 276, 298, and 323 K, covering 600– 6500 cm - 1 . The spectra were recorded at a resolution of 0.112 cm - 1 using a commercial Fourier transform spectrometer and a custom flowing sample delivery system. We report integrated absorption cross sections for intervals corresponding to the most prominent bands, compare the results with previously reported values, and discuss error sources, which are estimated as ∼ 7 % with systematic error the largest error source.
Rates and pathways for water diffusion and bulk flow through leaf tissue : a new technique for an old problem

Abstract Nuclear magnetic resonance was used to measure the relative content of [1H] nuclei in Acer platanoides leaf discs floating on either sucrose/D2O or concentrated PEG/H2O solutions. Data show that water diffusion and bulk flow follow different pathways through leaf tissue. Isotope exchange data fit accurately an equation derived for diffusion through a homogeneous medium with an average diffusion coefficient of 3.3×10−10 m2 s−1. A diffusion model featuring cell wall barriers was shown to be unnecessary. The diffusion rate is too fast to be consistent with transport solely through apoplastic channels and instead, water molecules appear to move directly through contiguous compartments. The discs lost water by osmosis into the PEG solution with an exponential decay function, which was shown to be consistent with a fractal model of bulk flow.
Relation of beta to gamma synthesis during the first trimester: an approach to prenatal diagnosis of thalassemia.

Relation of Beta to Gamma Synthesis During the First Trimester: An Approach to Prenatal Diagnosis of Thalassemia
Calcium-dependent mechanical oscillations occur spontaneously in unstimulated mammalian cardiac tissues.

In quiescent rat ventricular myocardium, bathed in solution of 2 mM Ca++ or less, it has been previously demonstrated that spontaneous microscopic oscillatory cell motion is present and interacts with an incident laser beam to produce scattered light intensity fluctuations which can be monitored to quantify the underlying motion. The present study shows that scattered light intensity fluctuations are not present under any conditions in frog atrial or ventricular preparations, but do occur in each type of mammalian cardiac tissue studied in the unstimulated state. The magnitude of scattered light intensity fluctuations in mammalian tissues varies with species and cellular Ca++ loading. In some tissues, e.g., rabbit or ferret ventricle, either an increase in the Ca++ concentration in the perfusate [( Ca++]e), reduction of perfusate Na+ concentration [( Na+]e), or addition of cardiac glycosides was required to elicit scattered light intensity fluctuations; in other tissues, however, e.g., the canine Purkinje fiber, atria, and ventricle, and guinea pig atria, scattered light intensity fluctuations were present at 2 mM [Ca++]e in the absence of experimental Ca++ loading. Scattered light intensity fluctuations were not affected by LaCl3, or verapamil, and were reversibly abolished by caffeine. When the pCa in the myofilament space is kept constant in detergent "skinned" fibers, scattered light intensity fluctuations are not present during contractile activation. We conclude: that scattered light intensity fluctuations are due to spontaneous intracellular Ca++ oscillations that require a functional sarcoplasmic reticulum; that the potential to exhibit these oscillations is a fundamental property of mammalian excitable cardiac cells; and that, in many mammalian tissues, these oscillations are present in the unstimulated state, even in the absence of experimental perturbations to enhance cell Ca++ loading.
Split-step Milstein methods for multi-channel stiff stochastic differential systems

Abstract We consider split-step Milstein methods for the solution of stiff stochastic differential equations with an emphasis on systems driven by multi-channel noise. We show their strong order of convergence and investigate mean-square stability properties for different noise and drift structures. The stability matrices are established in a form convenient for analyzing their impact arising from different deterministic drift integrators. Numerical examples are provided to illustrate the effectiveness and reliability of these methods.
Biomimetic sliding mode control of a prosthetic hand

Two methods of control for a prosthetic hand are presented. A fairly typical force feedback controller is compared to a novel biomimetic application of sliding mode control. The two controllers are evaluated analytically and subjectively by six human test subjects. The analytical experiments show that the human operators, on average, were more capable of effectively using the prosthetic hand with the biomimetic slding mode controller. The averaged results from the subjective evaluations indicated that the biomimetic sliding mode controller was more similar to operation of the human hand than the force controller.
Oscillatory behavior of a two‐phase natural‐circulation loop

A natural-circulation loop with water as the circulating fluid was studied for a range of operation covering two-phase flow. The work reported in this paper is concerned with the periodic oscillations of the flow rate and fluid temperature. The oscillations occurred even with constant heat input and constant cooling-water properties for the heat exchanger. The analytical approach includes a theoretical analysis of an open-ended system and numerical solutions obtained with an analogue computer for a simplified loop system. Also presented are the equations of motion, continuity, and energy, which were developed for a transient two-phase flow model for adaptation to more detailed numerical evaluations.
Late Cytomegalovirus Disease in Marrow Transplantation Is Predicted by Virus Load in Plasma

Late occurrence of cytomegalovirus (CMV) disease after day 100 after bone marrow transplantation has become an increasing problem; whether a quantitative measurement of CMV DNA in plasma by polymerase chain reaction (P-PCR) could be predictive of such disease was investigated. In a prospective study, 117 subjects undergoing allogeneic marrow transplantation were followed for 120 days with weekly CMV blood cultures, with day 35 bronchoalveolar lavage CMV cultures, with weekly CMV P-PCR, and with clinical follow-up for an additional 1-2 years. Despite preemptive ganciclovir, CMV disease occurred in 9% of subjects, with a median time of onset of 176 days. Quantitative CMV P-PCR was associated with the late development of CMV disease (P = .01). Of 43 subjects with positive P-PCR results, 23% developed CMV disease, but no disease occurred in the 74 subjects with negative P-PCR (P < .001), despite the fact that 22% had CMV isolated from lung lavage fluid and 32% had CMV isolated from blood.
Chemiluminescent Detection of Oxidants in Vascular Tissue: Lucigenin But Not Coelenterazine Enhances Superoxide Formation

Lucigenin-amplified chemiluminescence has frequently been used to assess the formation of superoxide in vascular tissues. However, the ability of lucigenin to undergo redox cycling in purified enzyme-substrate mixtures has raised questions concerning the use of lucigenin as an appropriate probe for the measurement of superoxide production. Addition of lucigenin to reaction mixtures of xanthine oxidase plus NADH resulted in increased oxygen consumption, as well as superoxide dismutase-inhibitable reduction of cytochrome c, indicative of enhanced rates of superoxide formation. Additionally, it was revealed that lucigenin stimulated oxidant formation by both cultured bovine aortic endothelial cells and isolated rings from rat aorta. Lucigenin treatment resulted in enhanced hydrogen peroxide release from endothelial cells, whereas exposure to lucigenin resulted in inhibition of endothelium-dependent relaxation in isolated aortic rings that was superoxide dismutase inhibitable. In contrast, the chemiluminescent probe coelenterazine had no significant effect on xanthine oxidase-dependent oxygen consumption, endothelial cell hydrogen peroxide release, or endothelium-dependent relaxation. Study of enzyme and vascular systems indicated that coelenterazine chemiluminescence is a sensitive marker for detecting both superoxide and peroxynitrite.
Web-Accessible Chemical Compound Information

Web-accessible chemical compound information resources are widely available. In addition to fee-based resources, such as SciFinder Scholar and Beilstein, there is a wide variety of freely accessible resources such as ChemSpider and PubChem. The author provides a general description of various fee-based and free chemical compound resources. The free resources generally offer an acceptable alternative to fee-based resources for quick retrieval. It is assumed that readers will be familiar with The Merck Index, Handbook of Chemistry and Physics, and Knovel Critical Tables.
SciAgents-an agent based environment for distributed, cooperative scientific computing

Problem solving using complex mathematical models of physical phenomena requires expert knowledge in a variety of fields of computer science, such as parallel computing and numerical methods. SciAgents is a problem-solving environment to allow these models to become truly easy to use for the application scientists, much like PC-based systems. It is based on the agent-oriented model of computing. In this paper, we discuss the design and architecture of SciAgents in the context of models based on partial differential equations. We present a set of artificial/computational intelligence techniques used by the cooperating agents that constitute SciAgents, which allows them to complete the program specification and to carry out the program execution with minimal need for user intervention. SciAgents permits the non-expert user to cost-effectively and easily develop software for solving complex mathematical models. It is scalable and allows for extensive reuse of existing software.
Monoclonal Antibodies, Human, Engineered

Antibodies are unique proteins of the immune system that exhibit high affinity and specificity, which have emerged as powerful molecular tools with a broad range of applications in research, diagnosis, and treatment of diseases. Since the 1970s, the hybridoma technology allowed the large-scale generation of rodent monoclonal antibodies with selectivity for a single antigen. However, the therapeutic efficacy of these antibodies was disappointing due to inefficient activation of the human effector functions, short half-life, and elevated immunogenicity that in some cases resulted in severe allergic reactions. The recombinant DNA technology allowed the engineering of a new generation of therapeutic antibodies by replacement of the murine components of antibodies with their human counterparts. This process started with the generation of mouse/human chimeric antibodies, followed by humanized antibodies, and finally fully human antibodies, each step significantly diminishing the immunogenicity of the antibodies. Importantly, the presence of the human fragment crystallizable (Fc) region in these antibodies makes them more effective in patients. These improvements resulted in a class of drugs that exhibit high specificity and functionality with less, if any, immunogenicity and toxicity, emerging as the fastest growing class of biological therapeutics. A rapidly growing number of human-engineered antibodies are being used as therapeutic agents alone or in combination with other therapeutic interventions for the treatment of a wide variety of diseases that include cancer, transplant rejection, allergy, and autoimmune disorders. Further, modifications in the structure of antibodies that modulate or add new biological properties are broadening the range of their clinical applications. Keywords: antibody; monoclonal; chimeric; humanized; hybridoma; antibody engineering