cssi/SciSciGPT-SciSciNet huggingface dataset:
SRC Kinase Phospho-Regulation of the Human Mitotic Kinesin Eg5

Eg5 is a human kinesin-5 that drives spindle pole separation during the early phases of mitosis. While a substantial body of work has revealed the role that Eg5 plays during mitosis, relatively little is known about how Eg5 activity is regulated throughout the cell cycle. Our data shows that endogenous Eg5 in HEK cells is phosphorylated on tyrosine residues. In silico predictors suggest three tyrosines in the Eg5 motor domain as targets of Src kinase phosphorylation. We show that these residues are phosphorylated specifically by Src kinase, but not by Wee1 kinase in vitro. Furthermore, cells expressing Eg5 constructs with a phosphomimetic mutation of Y211 to glutamate (Y211E) show significantly higher percentages of monopolar spindles than cells expressing wild-type Eg5. The Y211E mutation also significantly decreases Eg5 ATPase rates and motility in vitro. The proximity of the potential phosphorylation sites to the binding sites of small molecule inhibitors targeting Eg5 suggested that phosphorylation may interfere with drug binding. Isothermal calorimetry experiments show that phosphomimetic Eg5 constructs have significantly decreased affinity for S-trityl-L-cysteine (STLC). Together, these data suggest a role for the mitotic kinase Src in regulating Eg5 throughout the cell cycle by directly altering its motor characteristics. Such a role for post-translational modifications has not yet been investigated in Eg5. Additionally, the effect of phosphomimetic mutations on STLC binding suggests that phosphorylation may decrease the efficacy of Eg5 inhibitors that are currently in clinical trials. Future work will seek to confirm Src kinase as a regulator of Eg5 activity in cells and investigate phosphorylation as a potential cancer resistance mechanism.
Islamic Africa: A Select, Annotated Webography

In this brief essay and webography, I indicate ways to pursue the themes of Islamic Africa on the Web. Digital and online libraries about Islam and West Africa, and more broadly about the history and culture of predominantly Islamic parts of Africa, have been steadily growing in the last few years. To assist readers of Islamic Africa to appreciate the span of these rapidly expanding resources and their depth and usefulness, and hopefully to make use of them in learning or researching Islam in Africa, I present this select survey of digital resources.
Luminescent d0 scandocene complexes: photophysical studies and electronic structure calculations on Cp*2ScX (X = Cl, I, Me)

The room-temperature luminescence and photophysics of a series of early transition metal, first-row organometallic complexes with the general formula Cp*[sub 2]ScX (where Cp* is [eta][sub 5]-C[sub 5](CH[sub 3])[sub 5][sup [minus]] and X represents a [sigma]-donating ligand) are reported. Semiempirical molecular orbital calculations using the INDO/S method (ZINDO) have been performed. The calculations were carried out using full C[sub 5](CH[sub 3])[sub 5]- ligands for Cp*[sub 2]ScX, X = Cl, I, CH[sub 3]. The calculations indicate a large amount of metal and ligand orbital mixing in these d[sup 0] complexes, with the lowest unoccupied molecular orbitals consisting principally of Sc d-orbitals admixing with Cp* [pi]-orbitals. The highest-occupied molecular orbital for the chloride derivative contains primarily Cp* character, while that of the iodide species is mostly halogen in nature. The presence of a lone pair on X is requisite for room-temperature emission to occur, as evidenced by the observation of luminescence for X = Cl[sup [minus]], I[sup [minus]], and NHPh and by the lack of luminescence Cp*[sub 2]ScCH[sub 3] or Cp*[sub 2]ScCH[sub 2]Ph, under identifical conditions. 21 refs., 5 figs., 4 tabs.
Geo-acoustic characterization of calcareous seabed in the Florida Keys

Abstract Geotechnical and acoustic measurements on a set of 35 gravity cores and 11 box cores from two calcareous seabed locations in the lower Florida Keys that are characterized by contrasting environmental settings show significant differences in terms of vertical profiles of physical, acoustic, and geotechnical properties. The lower energy study site of the two is sheltered by the adjacent Dry Tortugas platform complex and reveals a higher porosity surface interval with significant changes in water content, density, and compressional wave velocity within the upper 25 cm. Sediment cores from open-water locations, such as those collected in the study area north of the Marquesas Keys, exhibit higher, less variable densities and lower velocities within the top 25 cm. This is attributed to consolidation associated with cyclic pressure variations from surface swells and strong tidal currents. Acoustic subbottom profiles display good correlation with shell-lag deposits observed in the gravity cores, although acoustic records lack the vertical resolution to detect variations in physical and acoustic properties on the order of those measured in this study. Calculated impedances at depths below 25 cm are significantly higher in the Dry Tortugas area and hence penetration of 4- and 15-kHz acoustic signals is less than at the Marquesas study site. From a geotechnical point of view, the sediments at both sites can be considered to behave like granular materials with little or no plasticity, no significant cementation, low compressibility, permeability highly dependent on void ratio, and moderate to high friction angles. A comparison with deep-sea sediments of mixed mineralogy shows that the effect of increasing calcium carbonate with decreasing clay content is to decrease plasticity and compressibility, and to increase friction angles. In other words, sediments shift from a cohesive to a granular nature as the carbonate content increases.
Review article: cyclooxygenase--a target for colon cancer prevention.

Summary Use of nonsteroidal anti-inflammatory drugs such as aspirin, which are known to inhibit cyclooxygenase activity, reduces the relative risk of colorectal cancer in humans by 40–50%. Animal and human studies have shown a 50–80% reduction in tumour multiplicity following treatment with a variety of nonsteroidal anti-inflammatory drugs. Two isoforms of cyclooxygenase have been described, cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). In 85% of colorectal adenocarcinomas taken from humans, COX-2 levels are 2–50-fold higher than levels in adjacent normal intestinal mucosa, while COX-1 levels are unchanged. These observations raise the question: Does COX-1 or COX-2 provide a useful target for prevention or treatment of colorectal cancer?
Role of Corticotropin‐Releasing Factor Receptor‐1 in Opiate Withdrawal

Previous studies indicate that corticotropin-releasing factor (CRF) contributes to the anxiety-like and aversive states associated with drug-induced withdrawal. The present study extends this work by analyzing the CRF receptor subtype involved in withdrawal responses. First, the influence of a selective CRF receptor-1 (CRF-R1) antagonist, CP-154,526, on opiate withdrawal behavior was examined. Pretreatment with the CRF-R1 antagonist significantly attenuated several behavioral signs of naltrexone-induced morphine withdrawal, including writhing, chewing, weight loss, lacrimation, salivation, and irritability, measured during the first hour of withdrawal. Next the expression of CRF-R1 was determined as a second measure of the involvement of this receptor in opiate withdrawal. Naltrexone-induced morphine withdrawal resulted in down-regulation of CRF-R1 mRNA in several brain regions, including the frontal cortex, parietal cortex, striatum, nucleus accumbens, and amygdala, but not in the hypothalamus or periaqueductal gray. Expression of CRF-R2, the other major CRF receptor subtype, was not down-regulated significantly by withdrawal in any of the regions examined, although morphine alone significantly increased levels of this receptor subtype. Taken together, the behavioral and receptor regulation findings indicate that CRF-R1 is the primary mediator of the actions of the CRF system on opiate withdrawal, although it is possible that CRF-R2 contributes to the response.
Use of the Ilizarov technique to treat radial nonunion with physeal arrest.

A growth arrest in a nonunion of the radius in a 10-year-old child was treated with the Ilizarov technique.
Adaptive Histogram Equalization For Automatic Contrast Enhancement Of Medical Images

With the large number of images that will be viewed simultaneously in a medical picture archiving and communication system (PACS) system in the diagnosis of a particular patient, image by image interactive contrast enhancement, at present by intensity windowing, becomes unacceptably time-consuming. Furthermore, windowing has disadvantages of being non-reproducible and providing adequate contrast primarily in selected image regions. The method of adaptive histogram equalization (ahe) appears to provide a solution to these problems. It is reproducible, automatic, and simultaneously provides contrast in all image regions. After summarizing the basic method, this paper will 1) describe a new contrast limited form of ahe that appears to allow its application to a wide variety of medical images, 2) present a VLSI machine design that will allow the calculation of ahe in a fraction of a second per megapixel, and 3) report the results of a study demonstrating that for chest CT images, ahe provides no measurable loss of diagnostic performance compared to the now standard windowing.
Spectral operators generated by Timoshenko beam model

We announce a series of results on the spectral analysis for a class of nonselfadjoint operators which are the dynamics generators for the systems governed by the equations of the Timoshenko beam model with a 2-parameter family of dissipative boundary conditions. Our results split into three groups. (1) We present asymptotic formulas for the spectra of the aforementioned operators (the spectrum of each operator consists of two branches of discrete complex eigenvalues) and for their generalized eigenvectors. (2) We show that these operators are Riesz spectral. This result follows from the fact that the systems of generalized eigenvectors form Riesz bases in the corresponding energy spaces. (3) We give the asymptotics of the spectra and the eigenfunctions for the nonselfadjoint polynomial operator pencils associated with these operators. Our results, on one hand, provide a class of nontrivial examples of spectral operators (nonselfadjoint operators which admit an analog of spectral decomposition). On the other hand, these results give a key to the solutions of various control and stabilization problems for the Timoshenko beam model using the spectral decomposition method.
Purchase process for capital equipment and services

Abstract This article develops some interactive dimensions of the industrial buying center. Buying group processes and outcomes were examined for purchases of capital equipment and industrial services in 31 firms. Qualitative as well as quantitative data were analyzed to test the soundness of an interactive communication perspective on buying, and the managerial implications to be drawn from such an analysis. Equipment and services purchase measures were found to differ reliably across several indices suggested by our theoretical orientation.
Rockefeller philanthropy and the “Flexner Report” on medical education in the United States

Ponders on whether Abraham Flexner was responsible for the change in medical education in North America in the early 20th century, owing to his report of 1910. Tries to demonstrate that medical education in the USA was part of a greater whole of major changes at that time. Concludes, though there was a philanthropic influence, Flexner (who refused to accept credit for change) was not the father of the medical reform plan.
Robust low-profile metasurface-enabled wearable antennas for off-body communications

This paper presents a low-profile metasurface-enabled wearable antenna operating in the newly released medical wireless body-are network (MBAN) band from 2.36 to 2.40 GHz for off-body communications. The performance of the antenna was made possible by the introduction of a properly designed anisotropic metasurface which consists of only a 2 by 2 array of I-shaped resonating elements. Together with the finite-sized metallic ground plane on the back of the metasurface, it provides a +90° reflection phase band to achieve the desired impedance matching for the planar monopole feed above the metasurface. The integrated antenna was fabricated and characterized, showing a strong correspondence between simulated and measured results. The resulting antenna has a remarkably low profile of only one-fiftieth of the operating wavelength, all while achieving a 5.5%-10 dB impedance bandwidth from 2.30 to 2.43 GHz, a gain of around 6.2 dBi, and a font-to-back ratio higher than 23 dB, thus making it a promising candidate for incorporation into various wearable systems.
Single photon level spectrum measurement at fiber communication band using frequency up-conversion technology

We have developed a polarization independent (PI) spectrometer based on frequency up-conversion technology for single photon level spectrum measurement at the fiber communication band. To overcome the polarization dependence of the frequency up-conversion process, we use two periodically poled lithium niobate (PPLN) waveguides with a polarizing beam splitter. We experimentally study the sensitivity and resolution of the PI up-conversion spectrometer. We demonstrate the spectrometer by way of a spectrum measurement of a single photon level signal in the communication band.
Dietary effects of the pharmacokinetics of three carcinogenic nitrosamines

Abstract The concentrations of N -nitrosodimethylamine (DMN), N -nitrosodiethylamine (DEN), and N -nitrosodibutylamine (DBN) were monitored as a function of time in the blood and liver of rats fed either a normal diet or a diet marginally deficient in lipotropes. The disappearance of each nitrosamine from the blood showed first-order kinetics. Hepatic clearance of DEN and DBN also followed first-order kinetics, but the time dependence of DMN concentration in liver tissue showed an anomalous behavior. Diet-related differences in the pharmacokinetic data did not explain the variations in carcinogenicity caused by diet.
Relationships Among Humor, Coping, Relationship Stress, and Satisfaction in Dating Relationships: Replication and Extension

This study applies the Transactional Theory of Emotion and Coping to understand how dating partners use humor to cope with relationship stress. College students (n = 244) reported on their perceptions of humor orientation, coping efficacy, relationship stress, and relationship satisfaction. As predicted by the transactional framework, the relationship between humor orientation and relationship stress was mediated by coping efficacy, while the model provided partial support for coping efficacy as a mediator of humor orientation and relationship satisfaction. Frequent positive humor use by dating partners in long distance (n = 66) and geographically close (n = 178) relationships resulted in greater coping efficacy, reduced levels of relationship stress, and increased relationship satisfaction. Findings from this study provide support for the use of the Transactional Theory of Emotion and Coping as a means of understanding the complex relationships among humor orientation, coping, relationship stress, and re...
Outcomes of Autologous Chondrocyte Implantation in a Diverse Patient Population

BackgroundAutologous chondrocyte implantation is indicated as a second-line treatment of large, irregularly shaped chondral defects after failure of first-line surgical intervention. This study examines the clinical results of a patient cohort undergoing autologous chondrocyte implantation and elucidates factors associated with subjective improvement after implantation.HypothesisAutologous chondrocyte implantation will result in long-term functional and symptomatic improvement.Study DesignCase series; Level of evidence, 4.MethodsThe cohort included 137 subjects (140 knees) who underwent autologous chondrocyte implantation of the knee. Mean defect size per patient was 5.2 ± 3.5 cm2 (range, 0.8-26.6 cm2). Patients averaged 30.3 ± 9.1 years of age (range, 13.9-49.9 years) and were followed for 4.3 ± 1.8 years (range, 2.0-9.7 years). Outcomes were assessed via clinical assessment and established outcome scales, including the Lysholm scale, International Knee Documentation Committee scale, and Short Form-12.Re...
Alcohol: Effects on Neurobehavioral Functions and the Brain

Alcoholism results from an interplay between genetic and environmental factors, and is linked to brain defects and associated cognitive, emotional, and behavioral impairments. A confluence of findings from neuroimaging, physiological, neuropathological, and neuropsychological studies of alcoholics indicate that the frontal lobes, limbic system, and cerebellum are particularly vulnerable to damage and dysfunction. An integrative approach employing a variety of neuroscientific technologies is essential for recognizing the interconnectivity of the different functional systems affected by alcoholism. In that way, relevant experimental techniques can be applied to assist in determining the degree to which abstinence and treatment contribute to the reversal of atrophy and dysfunction.
Multistage System Planning for Hydrogen Production and Distribution

Hydrogen is an energy carrier that has the potential to improve the sustainability of transportation fuels and reduce oil dependence. This paper presents a stochastic dynamic programming model for sequentially building a hydrogen production and distribution system. The decision variables are the sequence and locations of the central production sites and the corresponding distribution systems from supply to demand sites. A case study based on the geographic setting of Northern California is included, in which the hydrogen is produced via coal gasification and transported from plant to city gates (demand sites) by cryogenic liquid hydrogen trucks. Future demands for hydrogen are modeled as uncertain parameters, with an assumption that hydrogen fuel cell vehicle (HFCV) market penetration rate increases from 1% to 25% over a 20-year period. This model provides multistage decision support for long term transportation energy planning at national and regional levels.
Three-Dimensional Display Of Computed Tomographic Volume Images To Visualize Internal Organs

Volume images made up of "stacks" of parallel computed tomographic (CT) cross-sectional images are displayed in three dimensions utilizing the method of projection imaging. This technique involves the mathematical projection of the volume picture elements (voxels) of the 3-D image onto a plane to form a two-dimensional projection image which, for x-ray CT volume images, resemble conventional radiographs. Projection images formed at two angles of view, 2° to 8° apart, are utilized as stereo-pair projections to view the volume image in three dimensions. Before projection, selected regions of the volume image are partially dissolved or totally removed from the volume to enhance the visibility of remaining struc-tures. These processes, referred to as numerical tissue "dissolution" and "dissection", are utilized to overcome the undesired effects of superposition which occur as natural consequence of displaying a stack of cross sections as a volume image, i.e., deeper image regions are obscured by overlying structure. Examples are shown where overlying regions of the volume image have been "cut" from the volume to more clearly visualize deeper anatomy. Particular emphasis is given to the use of these methods in identifying two-and three-dimensional subregions of interest within the volume for further detailed view-ing and quantitative analysis. As an example, the use of the 3-D display of volume images to guide the process of identifying the optimal orientation of oblique section images through internal organs of the body is illustrated.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Dating annual layers of a shallow Antarctic ice core with an optical scanner

This study tests novel methods for automatically identifying annual layers in a shallow Antarctic ice core (WDC05Q) using images that were collected with an optical scanner at the US National Ice Core Laboratory. A new method of optimized variance maximization (OVM) modeled the density-related changes in annual layer thickness directly from image variance. This was done by using multi-objective complex (MOCOM) parameter optimization to drive a low-pass filtering scheme. The OVM-derived changes in annual layer thickness corresponded well with the results of an independent glaciochemical interpretation of the core. Individual annual cycles in image brightness were then identified by using OVM results to apply a depth-varying low-pass filter and fitting a second-order polynomial to a locally detrended neighborhood. The resulting map of annual cycles agreed to within 1 % of the overall annual count of the glaciochemical interpretation. Agreement on the presence of specific annual layer features was 96%. It was also shown that the MOCOM parameter optimization could calibrate the image-based results to match directly the date of a specific volcanic marker.
Traumatic Memory Is Special

Six types of studies show that father love sometimes explains as much or more of the variation in specific child and adult outcomes as does mother love. Sometimes, however, only father love is statistically associated with specific aspects of offsprings' development and adjustment, after control ling for the influence of mother love. Recognition of these facts was clouded historically by the cultural construction of fatherhood and father
Study of rainfall station locations in South Chickamauga Creek watershed

A 428-sq mi watershed was studied for the purpose of determining the number and location of reporting rainfall stations needed to provide the desired accuracy of average watershed rainfall for stream-flow prediction purposes. Data on storms occurring during a 12-month period are analyzed and a chart presented which shows the probable difference from average watershed rainfall to be expected for winter storms when various numbers of best and random stations are used to estimate rainfall.
Identification and developmental expression of src+ mRNAs in Xenopus laevis

Abstract Alternative splicing of src mRNA has been demonstrated in several vertebrate species to yield a neuron-specific form of src protein termed pp60+. The function of pp60+ is unknown. The early developmental expression pattern of src+ RNA has not been previously examined. We have identified and characterized src+ transcripts corresponding to the two src genes in Xenopus laevis using a reverse transcription/polymerase chain reaction ( RT PCR ) method. Both Xenopus pp60+ proteins have a 5-amino-acid insert in contrast to the 6-amino-acid insert in fish, birds, and mammals. Src+ mRNA first appears in neural plate stage Xenopus embryos, after neural induction signaling events but prior to neural differentiation. Analysis of dissected neural plate stage embryos showed that src+ mRNAs are localized to the neural plate. These findings suggest that pp60+ may play a role in elaboration of neuron structure.
Acoustic radiation force impulse imaging with an intra-cardiac probe

Acoustic radiation force impulse (ARFI) imaging has been demonstrated to provide insight into the mechanical properties of tissue. The quality of ARFI images is dependent on the amount of acoustic energy from the radiation force pulse reaching the focus. Intra-cardiac probes provide an advantage for ARFI imaging of cardiac tissue, as the probe can be positioned close to the region of interest. The resulting ARFI images display local variations in tissue stiffnesses and show promise for monitoring and assessing the progress of cardiac ablations. The Siemens AcuNav intra-cardiac probe was used to image a tissue-mimicking phantom having 3 mm diameter spherical inclusions with an elastic modulus eight times greater than the surrounding tissue. The ARFI sequences formed high contrast, high resolution images of these inclusions up to depths of approximately 1.5 cm. The ARFI pulse sequences resulted in 0.8°C temperature increase on the transducer face, and the time constant associated with the return to equilibrium temperature was approximately 300 ms. The probe was used to examine an excised segment of an ovine right ventricle with a surface lesion created from radiofrequency ablations (RFA). In areas of healthy tissue, the ARFI images did not show any stiffer regions that would indicate the presence of a lesion. Although the lesion was not visible in conventional B-mode images, the ARFI images were able to show the boundaries between the lesion and the surrounding tissue.
“Mode-Blind” Estimates of Deep Earth Resistivity

Traditional approaches to the global induction problem have often determined the conductivity structure of the earth for specific modes of the external source field. In the case of “disturbed time” (or Dst) epochs, workers have tended to use the P10 term, or, in the case of “quiet time” (or Sq or L) epochs, workers have used various low-order Pnm terms. Each of these “modes” has tended to lead to a distinct earth model which differs from those derived from other modes. Since one and only earth model should jointly “fit” any and all modes simultaneously, it is not clear what these separate models represent—we need an approach which is essentially “mode-blind”. We address this problem by applying an extension of the magnetic gradiometric technique to data from 31 standard magnetic observatories in the European sector. We employ the two years of hourly values culled by WINCH (1981) to 1) characterize the dominant statistical properties of the primary data set and reject outliers; 2) construct low order polynomial forms over the array of observatories; 3) estimate gradiometric response parameters; 4) explore model space for classes of earth models which account for all modes simultaneously, and which fit the data while minimizing the resistivity structure at depth.
Modulation by benzo[a]pyrene of epidermal growth factor receptors, cell proliferation, and secretion of human chorionic gonadotropin in human placental cell lines

Clinical observations indicate that maternal cigarette smoking has significant detrimental effects on fetoplacental development. The present study used human trophoblastic choriocarcinoma cell lines of placental origin to investigate the effects of benz[a]pyrene (BaP) on epidermal growth factor (EGF) receptors, cell proliferation and human chorionic gonadotropin (hCG) secretion. BaP decreased 125I-EGF binding and EGF receptor protein in a concentration-related manner in both BeWo and JEG-3 cell lines. The steady-state level of EGF receptor mRNA, however, was not changed significantly by BaP in either cell line. Cell proliferation was unchanged or slightly increased following exposure to 10 and 50 microM BaP in the presence of serum, whereas proliferation progressively decreased in cells exposed under serum-free conditions. The mitogenic effect of EGF was inhibited by cotreatment with BaP in both cell lines. Further study of trophoblast endocrine function showed that both basal and EGF-stimulated secretion of hCG was reduced significantly by BaP exposure in BeWo cells, whereas no adverse effect was seen in JEG-3 cells. Finally, cytochrome P450 1A1 (CYP1A1) was induced in a concentration-dependent manner by BaP in both cell lines. Thus, data indicate that the BaP-mediated loss of EGF receptors alters trophoblast proliferation and endocrine function, and that different mechanisms may be involved in the regulation of hCG secretion in BeWo and JEG-3 cells. In addition, this study supports the feasibility of using the BeWo and JEG-3 trophoblastic choriocarcinoma cell lines to investigate biomarkers and mechanisms of placental toxicity.
Protean Organizations: Reshaping Work and Careers to Retain Female Talent.

Purpose – This paper aims to understand women's careers better in order to help organizations make changes to increase female retention. Two specific questions are addressed: Are women adopting a protean career orientation by becoming career self‐agents?; and Are women's career decisions guided by the kaleidoscope values of challenge, balance, and authenticity? Results are used to discuss changes that organizations can make to better attract and retain female talent. Design/methodology/approach – Open‐ended semi‐structured interviews were conducted by telephone with 25 women graduates of a top ranked international business school located in the USA who had voluntarily left the workforce at some time in their career and had since returned to work. Findings – Results show that 17 of the women interviewed followed a protean career orientation when they returned to the workforce, finding part‐time or reduced‐hours positions or completely changing careers. Of the women, five returned to work following a traditional career orientation and three chose to return to a job rather than reinitiating their careers. The vast majority of the women who adopted a protean career were driven to do so in order to satisfy their need for balance in their lives. Overall, eight of the women expressed a need for authenticity in their careers and only two mentioned a desire for challenge. Many of them felt they had already satisfied their need for challenge earlier in their career, as the KCM suggests. Practical implications – As with protean careers, protean organizations adapt to evolving circumstances. Companies that recognize and respond to the need to reshape how work gets done and how careers are built will achieve a competitive advantage by attracting and retaining valuable female talent. Organizations should shift their focus from an emphasis on face time to an emphasis on results, giving employees more control over how, when, and where they work. They also need to move away from the traditional career model that emphasizes full‐time, continuous employment and instead embrace arc‐of‐the‐career flexibility that allows women to adopt a protean orientation, managing their own careers in order to align them with their personal values. Originality/value – The paper helps to explain the motives behind professional women' career moves and makes suggestions on how organizations can better attract and retain female talent.
Software Assurance for Model-Based Design

Within JPL and NASA, the emergence of model-based design will reformulate the design process. Simultaneously, the mission-critical role of software is increasing. Thus, the nature of software assurance must change accordingly. This paper examines the experience of using model-based design in the context of development of mission flight software and also covers how software assurance practices are being adapted to work with this approach. In the model-based development paradigm, novelty stems from the fact that many of the artifacts are in machine manipulable representations, not simply paragraphs of textual descriptions or drawings intended purely for human viewing. Furthermore, using tools that support the model-based paradigm allows automatic code generation to be employed, yielding significant portions of machine-generated source code as significant parts of the development efforts.
Cellular mechanisms underlying calcium‐proton interactions in cultured chick ventricular cells.

1. Cytosolic free Ca2+ concentration ([Ca2+]i) in cardiac muscle cells is influenced by many factors including intracellular pH. Intracellular alkalinization has been shown to reduce, whereas acidification has been shown to augment [Ca2+]i. We examined the cellular mechanisms underlying Ca2+-H+ interactions using cultured chick embryo ventricular cells. 2. Cells were loaded with fura-2 or BCECF (2,7-biscarboxyethyl-5(6)-carboxy-fluorescein) and changes in time-averaged [Ca2+]i or pHi were monitored continuously using a dual-wavelength spectrofluorometer. 3. Exposure of cells to 20 mM-NH4Cl (intracellular alkalinization) produced a rapid decrease in [Ca2+]i; subsequent wash-out of NH4Cl (intracellular acidification) resulted in an increase in [Ca2+]i to levels above control. Intracellular acidification produced by elevated CO2 content also resulted in an increase in [Ca2+]i. The Na+-H+ exchange inhibitor ethylisopropylamiloride (10 microM) inhibited completely the rise but not the fall in [Ca2+]i in response to manipulation of pHi with NH4Cl. 4. In the presence of caffeine (20 mM), NH4Cl produced a decrease in [Ca2+]i similar to that observed in the absence of caffeine, but subsequent removal of NH4Cl resulted in an increase in [Ca2+]i that was distinctly smaller than that observed in the absence of caffeine. Ryanodine (10 microM) had no significant influence on NH4Cl-induced changes in [Ca2+]i. 5. Following treatment with the mitochondrial inhibitors sodium cyanide (5 mM), CCCP (carbonyl cyanide m-chlorophenyl hydrazone, 10 microM) or rotenone (10 microM), the NH4Cl-induced decrease in [Ca2+]i was markedly diminished, but wash-out of NH4Cl resulted in increases in [Ca2+]i similar to those observed in control cells. 6. Inhibition of glycolysis with 20 mM-2-deoxyglucose did not significantly alter the changes in [Ca2+]i induced by NH4Cl addition or its wash-out, but 2-deoxyglucose plus cyanide abolished the decrease in [Ca2+]i produced by intracellular alkalinization and nearly completely blocked the increase in [Ca2+]i produced by acidification. 7. In all experiments, the increase in [Ca2+]i during wash-out of NH4Cl was inhibited by ethylisopropylamiloride.(ABSTRACT TRUNCATED AT 400 WORDS)
Dynamic fastest paths with multiple unique destinations (DynFast-MUD) — A specialized traveling salesman problem with intermediate cities

In this paper we present a fastest path algorithm that contains multiple unique destinations, which is a specialization of the Traveling Salesman Problem (TSP) with intermediate cities [1]. This algorithm can be used with Intelligent Transportation System (ITS) applications for determining the fastest route to travel to a set of destinations, such as required by delivery companies. The dynamic behavior of the algorithm is necessary for ITS applications since the amount of time to traverse a roadway in a vehicular network can change constantly. Assuming that all of the potential paths between all nodes in the transportation graph is known, the algorithm will determine the fastest route to a set of nodes in O(n3), where n is the number of nodes to visit. The algorithm was executed on theoretical and actual transportation graphs in FreeSim (http://www.freewaysimulator.com) [2], and an analysis of the running time and a proof of the correctness of the algorithm are included in this paper.
Mild induced hypothermia after out-of-hospital cardiac arrest: persisting doubts about patient safety.

In a study of the endovascular cooling system Alsius CoolGard™ combined with the Icy™ venous catheter, Pichon and colleagues concluded the effectiveness and safety of mild induced hypothermia (MIH) after out-of-hospital cardiac arrest resuscitation [1]. We are troubled because the study has reproduced several safety concerns about MIH that have not been confronted. First, the sixfold increase of the nosocomial bloodstream infection rate (13% versus control 2%) is most probably related to insertion of endovascular catheters for MIH [1]. Bloodstream infection in patients with endovascular catheters can become a significant cause of preventable morbidity and mortality [2]. Second, it is unclear why hypokalemia (75% of MIH cases) was dismissed as a factor for the incidence of cardiac dysrhythmia [1]. Temperature changes induce electrolyte shifts and thus influence the depolarization and repolarization times and the conduction velocity of action potentials within the myocardium, promoting aberrant conduction pathways. Electrolyte abnormalities associated with MIH can influence electrophysiological parameters of the myocardium, triggering dysrhythmia [3].
Increasing blood glucose variability heralds hypoglycemia in the critically ill.

Background Control of hyperglycemia improves outcomes, but increases the risk of hypoglycemia. Recent evidence suggests that blood glucose variability (BGV) is more closely associated with mortality than either isolated or mean BG. We hypothesized that differences in BGV over time are associated with hypoglycemia and can be utilized to estimate risk of hypoglycemia ( Materials and Methods Patients treated with intravenous insulin in the Surgical Intensive Care Unit of a tertiary care center formed the retrospective cohort. Exclusion criteria included death within 24 h of admission. We describe BGV in patients over time and its temporal relationship to hypoglycemic events. The risk of hypoglycemia for each BG measurement was estimated in a multivariable regression model. Predictors were measures of BGV, infusions of dextrose and vasopressors, patient demographics, illness severity, and BG measurements. Results A total of 66,592 BG measurements were collected on 1392 patients. Hypoglycemia occurred in 154 patients (11.1%). Patient BGV fluctuated over time, and increased in the 24 h preceding a hypoglycemic event. In crude and adjusted analyses, higher BGV was positively associated with a hypoglycemia (OR 1.41, P Conclusions BGV increases in the 24 h preceding hypoglycemia, and patients are at increased risk during periods of elevated BG variability. Prospective measurement of variability may identify periods of increased risk for hypoglycemia, and provide an opportunity to mitigate this risk.
The use of near field probe in the analysis of radome performance

This paper is comprised of an adaptation of tomographic techniques for the purpose of radome analysis, and a test of the resulting formulation. The formulation com bines plane-wave spectrum backpropagation and aperture integration to map transmitted field measurements over a radome surface. This type of analysis allows two methods of compensation for radome effects. The first method consists of modifying the radome structure to equalize the local transmission characteristics. The second method of compensation is yet untried, and utilizes the knowledge of the equivalent sources representing the radome effects on the antenna aperture. These equivalent sources are a by-product of the backpropagation step. Theoretically, compensation for radome effects on the antenna aperture can be accomplished by subtracting these equivalent currents from the original aperture currents.
The personal values of alcoholics and addicts

In a comparison of the personal values of male alcoholics and addicts, the major findings were: (a) the values of the two groups are quite similar; and (b) the combined values of the two groups are quite different from a sample of males from the general population. Further research to determine how many of the reported differences are a function of the Ss' drug abuse and how many are a function of their particular social background is suggested.
The ethologic model of phonetic development: I. Phonetic contrast estimators

This study defines phonetic product estimators of an ethologic model of phonetic contrast development and introduces some of their properties with the use of simulations. The model of phonetic development is presented in the behavioural biology tradition of ethology that includes a series of naturalistic and computational studies of children's phonetic development. Six children interacting with their mothers were studied from one to two years of age to discover patterns of emergence in phonetic and language development.Phonetic contrast is a key concept in the model and studies. Phonetic contrast refers to the ability to use different articulatory movements variably in time, a necessary skill for language acquisition. Children are hypothesized to have limited expressive resources for this ability to produce phonetically contrastive utterances which emerge into later language skills.The aim of these studies is to state and test different phonetic product model estimators of the role of phonetic contrast in...
Sarcocystis lindsayi n. sp. (Protozoa: Sarcocystidae) from the South American Opossum, Didelphis albiventris from Brazil

Abstract A new species, Sarcocystis lindsayi n. sp., is proposed for a parasite resembling Sarcocystis falcatula. It was obtained from the lungs and muscles of budgerigars (Melopsittacus undulatus) fed sporocysts from a naturally-infected South American opossum, Didelphis albiventris, from Jaboticabal, Brazil. Sarcocysts of S. lindsayi n. sp. in budgerigars are microscopic, up to 600 μm long and up to 50 μm wide. The cyst wall is up to 2 μm thick. Ultrastructurally, the sarcocyst wall consists of numerous slender villar protrusions (up to 2.0 μm long and up to 0.3 μm wide), each with a stylet at its tip. Schizonts in cell culture divide by endopolygeny leaving a residual body. Sporocysts are ∼ 12 × 7 μm. The parasite is genetically distinct from other organisms that also cycle between opossums and avian species and resemble S. falcatula. Diagnostic genetic variation has been observed in the nuclear large subunit ribosomal RNA gene, the internal transcribed spacer (ITS-1), and each of two other genetic loc...
Primate Origin of the CMT1A-REP Repeat and Analysis of a Putative Transposon-Associated Recombinational Hotspot

The CMT1A-REP repeat on chromosome 17p11.2-12 is proposed to mediate misalignment and meiotic unequal crossover leading to a 1.5 Mb pair duplication associated with Charcot-Marie-Tooth neuropathy type 1A (CMT1A) and a reciprocal deletion associated with hereditary neuropathy with liability to pressure palsies (HNPP). Restriction enzyme endonuclease mapping indicated that the size of the CMT1A-REP repeat is approximately 24 kb and DNA sequence analysis determined that the repeat is flanked by inverted Alu sequences. Full length Alu sequences are present at the centromeric ends of the proximal and distal CMT1A-REP repeats and at the telomeric end of the distal repeat. A truncated Alu sequence is present at the telomeric end of the proximal repeat suggesting that the distal CMT1A-REP repeat is the progenitor copy. The crossover breakpoints for a series of unrelated CMT1A and HNPP patients were mapped using a variant SacI site found only in the proximal CMT1A-REP repeat. Seventy-six percent (66/85) of patients had breakpoints which mapped to a 3.2 kb interval, providing further evidence for a recombinational hotspot within the CMT1A-REP repeat. A mariner-like element was mapped within the CMT1A-REP repeat approximately 700 bp centromeric to the 3.2 kb interval containing the hotspot. Analysis of this sequence suggested that it does not encode a functional transposon. By Northern blot analysis a cloned fragment from the CMT1A-REP repeat containing the mariner-like sequence detected a 2.2 kb transcript only in testis. Two cDNA clones which contain the mariner-like element were isolated from a human testis cDNA library. These clones which are interrupted by Alu and other repeats appear to be non-functional versions of the transposon. The functional relationship of the mariner-like element to the recombinational hotspot remains unknown. The origin of the CMT1A-REP repeat was investigated through an analysis of homologous sequences in non-human primates. Southern blot analysis indicated that the chimpanzee has two copies of a CMT1A-REP-like sequence, whereas gorilla, orangutan, and gibbon have a single copy. A high degree of conservation amongst non-human primates for restriction fragments specific to the human distal CMT1A-REP repeat provides further evidence that the distal repeat is the progenitor copy. The mariner-like sequence was detected in association with the CMT1A-REP sequence in all primates studied suggesting that the mariner-like element was introduced into the progenitor CMT1A-REP sequence prior to emergence of the proximal and distal CMT1A-REP repeats. These observations suggest that CMT1A-REP sequence appeared as a repeat before the divergence of chimpanzee and human, but after gorilla and human around 6 to 7 million years ago.
Fast cerebral functional signal in the 100-ms range detected in the visual cortex by frequency-domain near- infrared spectrophotometry

Brain activity is associated with physiological changes, which alter the optical properties of the tissue in the near-infrared part of the spectrum. Two major types of optical signals following functional brain activation can be distinguished: a slow signal due to hemodynamic changes and a fast signal, which is directly related to neuronal activity. The fast signal is small and therefore difficult to detect. We used a specially noise-optimized frequency-domain near-infrared spectrometer with a pi-sensor, which was expected to be particularly sensitive to deeper tissue layers, to investigate the human visual cortex during visual stimulation generated by a checkerboard. We were able to detect significant fast signals in single light bundles, but not in pi-signals. The fast signals were mostly collocated with strong slow hemodynamic signals, but showed a higher degree of localization than the latter. The latencies of 40 +/- 16 ms of the fast signals were similar between locations. Our results also indicate that the brain responds differently to a single and double (forth and back) reversal of the checkerboard, with a stronger reaction upon the double reversal.
Learning Rates and States from Biophysical Time Series: A Bayesian Approach to Model Selection and Single-Molecule FRET Data

Time series data provided by single-molecule Forster resonance energy transfer (smFRET) experiments offer the opportunity to infer not only model parameters describing molecular complexes, e.g., rate constants, but also information about the model itself, e.g., the number of conformational states. Resolving whether such states exist or how many of them exist requires a careful approach to the problem of model selection, here meaning discrimination among models with differing numbers of states. The most straightforward approach to model selection generalizes the common idea of maximum likelihood—selecting the most likely parameter values—to maximum evidence: selecting the most likely model. In either case, such an inference presents a tremendous computational challenge, which we here address by exploiting an approximation technique termed variational Bayesian expectation maximization. We demonstrate how this technique can be applied to temporal data such as smFRET time series; show superior statistical consistency relative to the maximum likelihood approach; compare its performance on smFRET data generated from experiments on the ribosome; and illustrate how model selection in such probabilistic or generative modeling can facilitate analysis of closely related temporal data currently prevalent in biophysics. Source code used in this analysis, including a graphical user interface, is available open source via http://vbFRET.sourceforge.net.
Production, purification and characterization of pectin methylesterase (PME) from Arthrobotrys oligospora

Arthrobotrys oligospora, when grown in synthetic medium with pectin as sole carbon source, produced pectin methylesterase (PME) on the fourth day under static conditions at 25C. Through ammonium sulfate fractionation and successive chromatography on hydroxyapatite and Sephadex G-100 a 26.4 fold purification was achieved. PME was stable between pH values of 5–8. Its optimum activity was at pH 7.5 and at 37C. The energy of activation (Ea) was determined to be 11.9 kcal/mole. It had Km of 0.9 mg/ml for pectin. The molecular weight of PME was found to be 50 kilo daltons by both Sephadex G-100 column chromatography and by SDS-PAGE. During electrophoresis PME appeared as a lipoprotein when prestained with sudan black-B.