cssi/SciSciGPT-SciSciNet huggingface dataset:
Site-Directed Mutagenesis of Histidine 245 in Firefly Luciferase: A Proposed Model of the Active Site†

Firefly luciferase catalyzes the highly efficient emission of yellow-green light from substrate luciferin by a sequence of reactions that require Mg-ATP and molecular oxygen. We previously reported [Branchini, B. R., Magyar, R. A., Marcantonio, K. M., Newberry, K. J., Stroh, J. G., Hinz, L. K., and Murtiashaw, M. H. (1997) J. Biol. Chem. 272, 19359-19364] that 2-(4-benzoylphenyl)thiazole-4-carboxylic acid (BPTC), a firefly luciferin analogue, was a potent photoinactivation reagent for luciferase. We identified a luciferase peptide 244HHGF247, the degradation of which was directly correlated to the photooxidation process. We report here the construction and purification of wild-type and mutant luciferases H244F, H245F, H245A, and H245D. The results of photoinactivation and kinetic and bioluminescence studies with these proteins are consistent with His245 being the primary functional target of BPTC-catalyzed enzyme inactivation. The possibility that His245 is oxidized to aspartate during the photooxidation reaction was supported by the extremely low specific activity ( approximately 300-fold lower than WT) of the H245D mutant. Using the crystal structures of luciferase without substrates [Conti, E., Franks, N. P., and Brick, P. (1996) Structure 4, 287-298] and the functionally related phenylalanine-activating subunit of gramicidin synthetase 1 [Conti, E., Stachelhaus, T., Marahiel, M. A., and Brick, P. (1997) EMBO J. 16, 4174-4183] as a starting point, we have performed molecular-modeling studies and propose here a model for the luciferase active site with substrates luciferin and Mg-ATP bound. We have used this model to provide a structure-based interpretation of the role of 244HHGF247 in firefly bioluminescence.
Gender of Primary Authors and Types of Research in Three Rehabilitation Counseling Journals 1990 to 1999

The authors reviewed all articles published in three rehabilitation counseling journals from 1990 through 1999 to identify the gender of the primary author for each article and the type of article....
CHEMISTRY OF DEICING ROADS: BREAKING THE BOND BETWEEN ICE AND ROAD

The rates for breaking the bond between ice and road surfaces are measured as a function of temperature, type of road surface, and chemical application. Surfaces of asphalt, concrete, and brick give indistinguishable results. Chemicals used include sodium chloride, calcium chloride, urea, and calcium magnesium acetate (CMA). The results are analyzed in terms of the maximum areas undercut and the rates at which the areas are undercut. The areas for all chemicals can be correlated with arguments based on freezing point depression. The rates seem consistent with diffusion controlled melting.
Controlled release of doxorubicin from pH-responsive microgels

Stimuli-responsive hydrogels have enormous potential in drug delivery applications. They can be used for site-specific drug delivery due to environmental variables in the body such as pH and temperature. In this study, we have developed pH-responsive microgels for the delivery of doxorubicin (DOX) in order to optimize its anti-tumor activity while minimizing its systemic toxicity. We used a copolymer of oligo(polyethylene glycol) fumarate (OPF) and sodium methacrylate (SMA) to fabricate the pH-responsive microgels. We demonstrated that the microgels were negatively charged, and the amounts of charge on the microgels were correlated with the SMA concentration in their formulation. The resulting microgels exhibited sensitivity to the pH and ionic strength of the surrounding environment. We demonstrated that DOX was efficiently loaded into the microgels and released in a controlled fashion via an ion-exchange mechanism. Our data revealed that the DOX release was influenced by the pH and ionic strength of the solution. Moreover, we designed a phenomenological mathematical model, based on a stretched exponential function, to quantitatively analyze the cumulative release of DOX. We found a linear correlation between the maximum release of DOX calculated from the model and the SMA concentration in the microgel formulation. The anti-tumor activity of the released DOX was assessed using a human chordoma cell line. Our data revealed that OPF–SMA microgels prolonged the cell killing effect of DOX.
Rapamycin does not affect post-absorptive protein metabolism in human skeletal muscle

Abstract Administration of the mTORC1 inhibitor, rapamycin, to humans blocks the increase in skeletal muscle protein synthesis in response to resistance exercise or amino acid ingestion. Objective To determine whether rapamycin administration influences basal post-absorptive protein synthesis or breakdown in human skeletal muscle. Materials/Methods Six young (26 ± 2 years) subjects were studied during two separate trials, in which each trial was divided into two consecutive 2 h basal periods. The trials were identical except during one trial a single oral dose (16 mg) of rapamycin was administered immediately prior to the second basal period. Muscle biopsies were obtained from the vastus lateralis at 0, 2, and 4 h to examine protein synthesis, mTORC1 signaling, and markers of autophagy (LC3B-I and LC3B-II protein) associated with each 2 h basal period. Results During the Control trial, muscle protein synthesis, whole body protein breakdown (phenylalanine Ra), mTORC1 signaling, and markers of autophagy were similar between both basal periods (p > 0.05). During the Rapamycin trial, these variables were similar to the Control trial (p > 0.05) and were unaltered by rapamycin administration (p > 0.05). Thus, post-absorptive muscle protein metabolism and mTORC1 signaling were not affected by rapamycin administration. Conclusions Short-term rapamycin administration may only impair protein synthesis in human skeletal muscle when combined with a stimulus such as resistance exercise or increased amino acid availability.
Error Bounds and Limiting Behavior of Weighted Paths Associated with the SDP Map X 1/2 SX 1/2

This paper studies the limiting behavior of weighted infeasible central paths for semidefinite programming (SDP) obtained from centrality equations of the form X1/2SX1/2 = $\nu$ W, where W is a fixed positive definite matrix and $\nu > 0$ is a parameter, under the assumption that the problem has a strictly complementary primal-dual optimal solution. It is shown that a weighted central path as a function of $\sqrt{\nu}$ can be extended analytically beyond $0$ and hence that the path converges as $\nu \downarrow 0$. Characterization of the limit points of the path and its normalized first-order derivatives are also provided. As a consequence, it is shown that a weighted central path can have two types of behavior: it converges either as ${\Theta}(\nu)$ or as ${\Theta}(\sqrt{\nu})$ depending on whether the matrix W on a certain scaled space is block diagonal or not, respectively. We also derive an error bound on the distance between a point lying in a certain neighborhood of the central path and the set of primal-dual optimal solutions. Finally, in light of the results of this paper, we give a characterization of a sufficient condition proposed by Potra and Sheng which guarantees the superlinear convergence of a class of primal-dual interior-point SDP algorithms.
Power Amplifier Simulations

Summary form only given. Computer Aided Engineering tools can be particularly useful for simulating and designing power amplifiers. This presentation outlines some of the simulations that can be carried out and includes a number simulation results. Power amplifier design often can be enhanced by nonlinear simulation, provided that an accurate model is available, which is assumed here.
An evaluation of the psychometric properties of the Purdue Pharmacist Directive Guidance Scale using SPSS and R software packages.

Abstract Background The Purdue Pharmacist Directive Guidance (PPDG) Scale was developed to assess patients’ perceptions of the level of pharmacist-provided (1) instruction and (2) feedback and goal-setting—2 aspects of pharmaceutical care. Calculations of its psychometric properties stemming from SPSS and R were similar, but distinct differences were apparent. Objective Using SPSS and R software packages, researchers aimed to examine the construct validity of the PPDG using a higher order factoring procedure; in tandem, McDonald's omega and Cronbach's alpha were calculated as means of reliability analyses. Methods Ninety-nine patients with either type I or type II diabetes, aged 18 years or older, able to read and write English, and who could provide written-informed consent participated in the study. Data were collected in 8 community pharmacies in New Mexico. Using R, (1) a principal axis factor analysis with promax (oblique) rotation was conducted, (2) a Schmid-Leiman transformation was attained, and (3) McDonald's omega and Cronbach's alpha were computed. Using SPSS, subscale findings were validated by conducting a principal axis factor analysis with promax rotation; strict parallels and Cronbach's alpha reliabilities were calculated. Results McDonald's omega and Cronbach's alpha were robust, with coefficients greater than 0.90; principal axis factor analysis with promax rotation revealed construct similarities with an overall general factor emerging from R. Conclusions Further subjecting the PPDG to rigorous psychometric testing revealed stronger quantitative support of the overall general factor of directive guidance and subscales of instruction and feedback and goal-setting.
Graphoglyptid Burrows in Modern Deep-Sea Sediment

The complex, highly patterned, invertebrate burrow systems known as "graphoglyptids" in ancient sedimentary rocks have now been recovered in box cores of modern deep-sea sediment. Spiroraphe, Cosmoraphe, and Paleodictyon occur as grooves in the tops of washed cores, and they apparently were produced and maintained as horizontal tunnel systems just a few millimeters below the sediment surface. These burrows, which are important as indicators of deepwater sedimentary environments in ancient strata, have been predicted in the modern deep sea but have not been found there until now.
Droplet formation, detachment, and impingement on the molten pool in gas metal arc welding

A mathematical model is developed to describe the globular transfer in gas metal arc welding (GMAW). This work is both theoretical and experimental. Using the volume-of-fluid (VOF) method, the fluid-flow and heat-transfer phenomena are dynamically studied during the following processes: droplet formation and detachment, impingement of a droplet on a solid substrate, impingement of multiple droplets on the molten pool, and solidification after the arc extinguishes. A He-Ne laser, in conjunction with the shadow graphing technique, is used to observe the metal transfer processes. Theoretical predictions and experimental results are in close agreement, suggesting that the theoretical treatment of the model is good.
Impurity incorporation and doping efficiency in a-Si:H.

A chemical equilibrium model of impurity incorporation in a-Si:H leads to a simple expression for the doping efficiency \ensuremath{\eta} of substitutional impurities I in terms of the impurity distribution coefficient, d(I), and the gas-phase impurity mole fraction, ${\mathit{X}}_{\mathit{I}}$; \ensuremath{\eta}==[${\mathit{I}}_{4}$]/[I]\ensuremath{\propto}(d(I)${)}^{\mathrm{\ensuremath{-}}1}$${\mathit{X}}_{\mathit{I}}^{\mathrm{\ensuremath{-}}1/2}$. In order to test this model, the distribution coefficients of As and P were measured over a wide range of a-Si:H deposition conditions from which \ensuremath{\eta} and the impurity incorporation rate were determined. An approximate analytical expression for d(I) has been fitted to the data and various impurity-incorporation mechanisms are considered to account for its form. The resulting intuitive, analytical expressions for the incorporation rate and doping efficiency of substitutional impurities in a-Si:H are valid for most deposition conditions.
MANAGEMENT OF EXTREMITY SARCOMAS

Soft tissue sarcomas remain an uncommon neoplasm. They do, however, provide a significant model for the examination of genetic predisposition, natural history, and therapeutic strategies for localized, regional and disseminated disease. Approaches developed in these solid tumours may well provide a rational basis for the management of other malignancies.
Introduction: The Uses and Evaluation of Qualitative Research It's Not What You Do when You Don't Have Data or Don't Know Statistics

If ever there was an area of inquiry that should be approached from the perspective of interpretive social science, this is one. It is apparent even to the most casual observer that aging has multi...
Congenital Muscular Ventricular Septal Aneurysm: Report of Four Cases and Review of the Literature

We describe a rare association between congenital muscular ventricular septal aneurysm (MuVSA) and right heart lesions, with emphasis on echocardiographic diagnosis, clinical presentation, and outcome. Our four cases of MuVSA occurred in combination with either pulmonary atresia with intact ventricular septum (PAIVS; three patients) or absent pulmonary valve syndrome with severe tricuspid stenosis (one patient). MuVSA and right heart lesions were detected in utero in three patients. The three patients with PAIVS and MuVSA survived with no significant morbidity from the septal aneurysm at 3- to 5-year follow-up. The presence of MuVSA did not negatively affect the outcome of our patients.
Staggered pattern charge collection: Antenna technique to improve RF energy harvesting

This paper introduces the theory of N-by-N staggered pattern charge collectors (SPCC) and a methodology to design and optimize SPCCs for maximum energy harvesting efficiency. The SPCC uses multiple sub-arrays to form an aggregate gain pattern for harvesting RF wireless energy more efficiently than a single antenna or a collection of antennas occupying a similar footprint when the transmitter location is unknown.
β-Ketoacyl decarboxylase activity in spores and mycelium of Penicillium roqueforti

Abstract 1. 1. Resting spores, germinated spores, and mycelium of Penicillium roqueforti actively decarboxylate (β-ketolauric acid to 2-undecanone. The rate of 2-undecanone formation increases as resting spores germinate and activity is highest in mycelium. 2. 2. Glucose stimulated the formation of 2-undecanone by resting spores but had no effect on activity in mycelium. 3. 3. The enhanced methyl ketone production in spores is attributed to the progressive increase in activity of β-ketoacyl decarboxylase as spores germinated. 4. 4. Cell-free extracts obtained from mycelium contained heat stable and heat labile species of β-ketoacyl decarboxylase. 5. 5. Optimum pH for the conversion of β-ketolaurate to 2-undecanone was 6.5–7.0. 6. 6. Biphasic substrate saturation curves and a discontinuous slope in Arrhenius plot for β-ketoacyl decarboxylase suggested the existence of two species of ketoacyl decarboxylase in P. roqueforti .
A new method of two-resuscitator CPR

Standard two-resuscitator cardiopulmonary resuscitation (CPR) (one resuscitator providing Bag Valve Mask (BVM) ventilation and one chest compressions) was compared with a modified method where one resuscitator held the mask while the second provided ventilation and compressions. Twenty-two subjects used both methods in random order on a recording manikin equipped to measure minute volume (Vm), tidal volume (Vt), respiratory rate (RR), compression rate (CR) and depth. Vm and Vt were greater with modified CPR, but the CR was slower. Percent of compressions 51 mm did not differ between techniques ((Modified--VM, 12.6 1 (S.D. 2.5); Vt, 1110 ml (S.D. 116); CR, 57 (S.D. 11), 51 mm 58% (S.D. 41); Standard--Vm, 9.7 1 (S.D. 3.8); Vt, 640 ml (S.D. 230); CR, 75 (10), 51 mm 38% (S.D. 38)). Modified CPR greatly improves ventilation but reduces CR.
Calbindin D28K immunoreactive neurons in vomeronasal organ and their projections to the accessory olfactory bulb in the rat

The vomeronasal system is a nasal chemosensory system involved in pheromone detection. The chemosensory receptor neurons are located in the sensory epithelium of the vomeronasal organ (VNO). Their axons terminate in the glomeruli of the accessory olfactory bulb (AOB). In this study, we examined the expression of calbindin D28k (CB) in the rat VNO and AOB. In the VNO, a subpopulation of receptor neurons in the middle layer of the sensory epithelium was immunostained with antibodies to CB. Their axons could be traced to terminate in a group of glomeruli in the anterior half of the AOB glomerular layer. This group of CB-immunostained glomeruli in the anterior half of the AOB included a few large glomeruli close to the boundary between the anterior and posterior halves of the AOB, and several small glomeruli scattered in the anterior region of the AOB glomerular layer. The positions of the CB-immunostained glomeruli in the AOB, especially those close to the anterior-posterior boundary, were similar in the two bulbs and in different rats. No sex difference was found. A developmental study showed that the CB-immunoreactive receptor neurons in the middle layer of the VNO sensory epithelium and CB-immunoreactive glomeruli in the anterior AOB were present on the 14th postnatal day and older. The distribution pattern of the CB-immunostained receptor neurons and their localized projection suggest the possibility that these neurons may express the same or functionally related pheromone receptor genes.
Corneal edema: cause and treatment

Corneal edema, adequately understood and appropriately treated, has a good prognosis. The pathophysiological bases and the various causes are considered. Goals and techniques of medical and surgical therapies are reviewed.
Taxonomic reassessment of the ichnogenus beaconichnus and additional examples from the Carboniferous of Kansas, U.S.A.

The ichnogenus Beaconichnus (Gevers 1973), an arthropod trace fossil, includes very different forms that comprise five ichnospecies, namely B. darwi‐nunt (Gevers 1971), B. gouldi (Gevers 1971), B. ahtarcticum (Gevers 1971), B. giganteum Gevers and Twomey 1982, and B. wrrighti Gevers and Twomey 1982. The original diagnosis of Beaconichnus is rather vague and potentially may accomodate virtually every arthropod trackway described from the fossil record. In view of these problems, the validity of Beaconichnus is reassessed and each of its ichnospecies is reviewed. We conclude that B. darwinum is a junior synonym of Diplopodichnus biformis Brady 1947; B. antarcticum should be regarded as Palmich‐niunt antarcticum; and B. wrighti is a nomen nudum. Additionally, we agree with previous proposals in considering B. gouldi as the senior synonym of B. giganteum, and including it in Diplichnites Dawson 1873. Therefore, we suggest that the ichnogenus Beaconichnus is best disregarded. Additionally, we describe specimen...
New family of light beams and mirror shapes for future LIGO interferometers

Advanced LIGO's present baseline design uses arm cavities with Gaussian light beams supported by spherical mirrors. Because Gaussian beams have large intensity gradients in regions of high intensity, they average somewhat poorly over fluctuating bumps and valleys on the mirror surfaces (thermal noise). Flat-topped light beams (mesa beams) are being considered as an alternative because they average over thermal noise more effectively. However, the proposed mesa beams are supported by nearly-flat mirrors, which experience a very serious tilt instability. In this paper we propose an alternative configuration in which mesa-shaped beams are supported by nearly-concentric spheres, which experience only a weak tilt instability. The tilt instability is analyzed for these mirrors in a companion paper by Savov and Vyatchanin. We also propose a one-parameter family of light beams and mirrors in which, as the parameter alpha varies continuously from 0 to pi, the beams and supporting mirrors get deformed continuously from the nearly-flat-mirrored mesa configuration (FM) at alpha=0, to the nearly-concentric-mirrored mesa configuration (CM) at alpha=pi. The FM and CM configurations at the endpoints are close to optically unstable, and as alpha moves away from 0 or pi, the optical stability improves.
Predetermined Electronic Counter

Proof is given that any integral scaling base can be obtained using binary counters with appropriate feedback connections. As examples, two different sets of feedback connections are given for each integer between 2r-1and 2r.
Axions in inflationary cosmology

Abstract The problem of the cosmological constraints on the axion mass is re-examined. It is argued that in the context of inflationary cosmology the constraint m a ≳10 −5 eV can be avoided even when the axion perturbations produced during inflation are taken into account. It is shown also that in most axion models the effective parameter ƒ a rapidly changes during inflation. This modifies some earlier statements concerning isothermal perturbations in the axion cosmology. A hybrid inflation scenario is proposed which combines some advantages of chaotic inflation with specific features of new and/or extended inflation. Its implications for theaxion cosmology are discussed.
Twenty-Five Year Experience With the St. Jude Medical Mechanical Valve Prosthesis

Background We evaluated all adult St. Jude mechanical valve recipients at our institution since the initial implant in January 1979 and now present our 25-year experience. Methods Nine hundred forty-five valve recipients were followed prospectively at 12-month intervals from January 1979 to December 2007. Results Operative mortality was 3% in the aortic valve recipients and 5% in the mitral valve recipients. Follow-up was 95% complete. Among aortic valve recipients, late actuarial survival was 81% ± 2%, 59% ± 2%, 41% ± 3%, 28% ± 3%, and 17% ± 4% at 5, 10, 15, 20, and 25 years, respectively. Twenty-five–year freedom from reoperation, thromboembolism, bleeding, and endocarditis was 90% ± 2%, 69% ± 5%, 67% ± 3%, and 9% 3 ± 2% respectively. Among mitral valve recipients late actuarial survival was 84% ± 2%, 63% ± 3%, 44% ± 3%, 31% ± 3%, and 23% ± 4% at 5, 10, 15, 20, and 25 years, respectively. Twenty-five–year freedom from reoperation, thromboembolism, bleeding and endocarditis was 81% ± 10%, 52% ± 8%, 64% ± 6%, and 97% ± 1%. Freedom from valve-related mortality and morbidity at 25 years was 26% ± 7% and 29% ± 6% for aortic and mitral valve replacement, respectively. Freedom from valve-related mortality was 66% ± 8% and 87% ± 3% for aortic and mitral valve replacement, respectively. Conclusions These results compare favorably with those for other mechanical prostheses. After two and a half decades of observation with close follow-up, the St. Jude mechanical valve continues to be a reliable prosthesis.
Cellular growth in various regions of the developing rat brain.

Extract: The cellular growth patterns in whole brain, cerebrum, cerebellum, hippocampus, and brainstem were examined in rats between 6 and 22 days of age. When weight alone was measured, little difference was seen between the various regions; however, when cell number (DNA) or protein per cell (protein: DNA) was measured, regional differences became very striking. In the cerebellum, DNA content increased 8.5 fold between 6 and 17 days and subsequently tapered off. The protein: DNA ratio declined during this period. Although the increase in cell number in the cerebrum was only 2.5 fold, it continued until 21 days, at which time the experiment was terminated. After 10 days there was also an increase in the protein: DNA ratio. In the brainstem, there was a modest increase in cell number between 6 and 14 days. After 10 days the protein: DNA ratio increased 4 fold. In the hippocampus, there was a discrete increase in cell number only between 14 and 17 days. These data demonstrate the existence of distinct regional patterns of cellular growth during postnatal maturation of rat brain. Speculation: The brain, although often viewed as a discrete organ, is composed of a number of anatomically distinct regions that perform separate and unique functions. Previous data from this laboratory have shown that cell division ceases in whole rat brain by 21 days postnatally and in whole human brain by six months of age. This study demonstrates that various regions of rat brain have different rates of cell division and that the entire pattern of cellular growth is regionally specific. Since certain functions are regionally controlled, it is possible that the regional growth patterns described here have functional correlates. Alteration in the environment (nutrition) is known to affect the rate of cell division in whole brain. It is possible that environmental effects may be regionally specific. By studying the effects of environmental stimuli (anoxia or malnutrition) on regional growth patterns and correlating these effects with functional changes, it may be possible to relate cellular changes to functional deficits.
R3 + D3 = A Learning Tool for Science and Engineering

The public benefits from a basic understanding not just of science but of engineering. However, people understand the scientific method better than the engineering approach, although they sense that the two are different. Simple memory tools could help teachers and students not only understand but remember and appreciate the different uses of the two approaches in understanding our world and in changing it. Checkland's concise description of the scientific method using three key words of reduce, repeat, and refute is proposed as a tool for remembering key components of the scientific method. A similar memory tool for the engineering approach could help teachers and students understand and remember the basic differences between and the appropriate uses of the two approaches. A three-word memory tool is proposed: determine, develop, and deploy. Our purpose is to elicit reaction to the conceptual learning tools proposed.
Neither Bandits nor Madmen: Modern African Insurgents

African Guerrillas: Raging against the Machine. Edited by Morten Boas, Kevin C. Dunn Boulder: Lynne Rienner Publishers, 2007. 275 pp., $58.00 cloth (ISBN: 1-58826-495-4), $23.50 paper (ISBN: 1-58826-471-8). One of the notable characteristics of the African political landscape at the beginning of the twenty-first century is the persistence of political violence perpetrated by armed insurgencies. Because guerrilla movements have such a far reaching impact, not only on politics and the peace and security of the continent but also on the pace of economic development and social stability, it is critical for scholars and practitioners alike to accurately understand the motives, sources, and nature of African guerrilla movements. In their provocative edited volume, African Guerrillas: Raging against the Machine , Morten Boas and Kevin Dunn provide a reconceptualization of guerrilla movements. Specifically, they and their contributors challenge the facile assumption that African movements can be understood in terms of “single-factor” explanations that regard contemporary insurgents as “devoid of any kind of political agenda” or “greed-based approaches [that] present them as bandits” (p. 1). As the contributors show, not only are these explanations empirically suspect, they also leave policymakers with few options for dealing with guerilla movements—short of brute force. Politically motivated insurgents can be negotiated with; bandits cannot. At its core, African Guerrillas mounts a fundamental critique of the “insular, positivist-dominated field of US political science” (p. 4). Boas and Dunn advocate a “holistic, historically grounded approach” to understanding the complexities of African guerrilla movements, which “are best understood as rational responses to the composition of African states and their polities” (p. 4). Current guerrilla movements, they write, “seem more like manifestations of rage against the ‘machinery’ of dysfunctional states, their equally fragmented and corrupted institutions and the uneven impact of a globalized modernity” (p. 5). Importantly, the contributors to African Guerrillas employ this contextually grounded approach throughout the volume. After framing the …
Flow characterization using PIV measurements in a low aspect ratio randomly packed porous bed

Low aspect ratio porous beds (bed width to bead diameter) have engineering applications such as catalytic reactors, combustors and heat exchangers. The nature of the packing within the bed and the influence of the near-wall region especially for randomly packed beds are expected to affect the velocity field and consequently the statistical characteristics of the flow. Planar PIV measurements were taken using refractive index matching at discrete locations throughout a randomly packed bed with aspect ratio of 4.67 for steady, low pore Reynolds number flows, Re pore ~ 4. Details of the measurement uncertainties as well as methods to determine local magnification and determination of the dynamic velocity range are presented. The data are analyzed using the PIV correlation averaging method with the largest velocity uncertainties arising from out-of-plane motion. Results show the correspondence with the geometric and velocity correlation functions across the bed and that the centerline of the bed shows a random-like distribution of velocity with an integral length scale on the order of one hydraulic diameter (or 0.38 bead diameters based on the porosity for this bed). The velocity variance is shown to increase by a factor of 1.8 when comparing the center plane data versus using data across the entire bed. It is shown that the large velocity variance contributes strongly to increased dispersion estimates and that based on the center plane data of the variance and integral length scales, the dispersion coefficient matches well with that measured in high aspect ratio beds using global data.
Grace Camet® metal monolith catalytic emission control technologies

Abstract The properties of Grace Camet® metal monolith catalysts are compared with washcoated commercially-available ceramic substrate-based catalysts. Camet® catalysts have a higher void fraction and geometric surface area per unit volume. Mass transfer and pressure drop correlations developed for Camet® catalysts show that Camet® catalysts have a higher mass transfer-limited activity at a given pressure drop. The implications of substrate design on catalytic performance are discussed. The paper provides information on the commercial performance of Grace Camet® three-way, carbon monoxide oxidation, and Low Temperature-Dual Function catalysts.
A blood stem cell transplant in a person with concomitant Hodgkin disease and testicular carcinoma

We report a patient with concomitant Hodgkin disease and testicular carcinoma who received MOPP chemotherapy and radiation therapy followed by etoposide and cisplatin. The testicular cancer recurred and he received ifosfamide, vinblastine and cisplatin followed by a high-dose carboplatin and etoposide blood stem cell transplant. He has been in complete remission for 6 months.
What drives global security and insecurity

The conjunctural issues marking our hard times are linked to the longue duree in a constellation called hyperconflict.1 To introduce this concept, I want to highlight common dimensions of three emblematic concerns that have grabbed public attention – oil spills, debt, and bailouts. This probing will help frame analytical questions and encapsulate my argument about what is driving global restructuring. 1 James H. Mittelman, Hyperconflict: Globalization and Insecurity (Stanford, CA: Stanford University Press, 2010).
Forces acting upon the solid phase of a porous medium

In dieser Arbeit wird die Mechanik poroser Korper im Rahmen einer Theorie der Mischungen behandelt. Es werden porose Korper betrachtet, die aus einer festen Phase und einer willkurlichen Zahl flussiger Phasen bestehen. Einige bekannte Gleichungen fur zwei- und dreiphasige Korper werden als Spezialfalle abgeleitet.
Religiosity and risky sexual behavior in African-American adolescent females

Abstract Purpose The full text of this article is available via JAH Online at www.elsevier.com/locate/jahonline To examine the association between religiosity (defined by frequency of engaging in religious/spiritual activities) and African-American adolescent females' sexual behaviors, attitudes toward sex, and ability to negotiate safer sex. Methods Between December 1996 and April 1999, 1130 female adolescents were screened for eligibility in a sexually transmitted disease (STD)/human immunodeficiency virus (HIV) prevention trial. Data collection was achieved through a confidential self-administered questionnaire that examined religiosity and a structured interview regarding sexual behavior. Descriptive statistics were used to characterize the sociodemographics of the sample and logistic regression was used to measure the association between religiosity and the outcome variables. Results In the study sample ( n = 522), 64% of the adolescents had higher religiosity scores based on a 4-item scale (α = .68). Results indicate that adolescents who had higher religiosity scores were significantly more likely to have higher self-efficacy in communicating with new, as well as steady male partners about sex; about STDs, HIV, and pregnancy prevention; and in refusing an unsafe sexual encounter. These adolescents were also more likely to have initiated sex at a later age, used a condom in the past 6 months, and possess more positive attitudes toward condom use. Conclusions Results from this study indicate a relationship between religiosity and sexual behaviors, attitudes toward sex, and ability to negotiate safer sex.
Enhanced action of apigenin and naringenin combination on estrogen receptor activation in non-malignant colonocytes: implications on sorghum-derived phytoestrogens

Activation of estrogen receptor-β (ERβ) is an important mechanism for colon cancer prevention. Specific sorghum varieties that contain flavones were shown to activate ER in non-malignant colonocytes at low concentrations. This study aimed to determine positive interactions among estrogenic flavonoids most relevant in sorghum. Apigenin and naringenin were tested separately and in combination for their ability to influence ER-mediated cell growth in non-malignant young adult mouse colonocytes (YAMC). Sorghum extracts high in specific flavanones and flavones were also tested. Apigenin reduced ER-mediated YAMC cell growth comparable to physiological levels of estradiol (E2, 1 nM) at 1 μM; naringenin had similar effect at 10 μM. However, when combined, 0.1 μM apigenin plus 0.05 μM naringenin produced similar effect as 1 nM E2; these concentrations represented 1/10th and 1/200th, respectively, of the active concentrations of apigenin and naringenin, demonstrating a strong enhanced action. A sorghum extract higher in flavones (apigenin and luteolin) (4.8 mg g−1) was more effective (5 μg mL−1) at activating ER in YAMC than a higher flavanone (naringenin and eriodictyol) (28.1 mg g−1) sorghum extract (10 μg mL−1). Enhanced actions observed for apigenin and naringenin were adequate to explain the level of effects produced by the high flavone and flavanone sorghum extracts. Strong positive interactions among sorghum flavonoids may enhance their ability to contribute to colon cancer prevention beyond what can be modeled using target compounds in isolation.
Liquid crystals for unsteady surface shear stress visualization

Daniel C. Reda* Wind Energy Research Division Sandia National Laboratories Albuquerque, NM 87185 Oscillating airfoil experiments were conducted to test the frequcncy response of thermochromic liquid crystal coat ings to unsteady surface shea r stresses under isothcrrnal-flow conditions. The model was an NACA0015 airfoil, cxposed to an incompressible flow at a freestrcarn Reynolds number (based on chord) of 1.14 x 106. Angle-of-attack forcing functions were sine waves of amplitude ? 10" about each of three mean angles of attack: O0, l o o , and 20°. Frequencies of oscillation were 0.2, 0.6 and 1.2 hertz, corresponding to reduced frequencies of 0.0055, 0.0164 a n d 0.0328. D a t a acquisi t ion was accomplished by video recording. Observations showed the liquid crystal technique capable of visualizing high surface shear stress zones over the stated dynamic range in a continuous and reversible manner.
A legal-ethical analysis of reproductive endocrinologists' right to refuse ovulation induction to patients with diminished ovarian reserve.

Purpose Review of the legal and ethical basis for reproductive endocrinologists to refuse ovulation induction to patients with diminished ovarian reserve.
Density, local composition and diffusivity of aqueous choline chloride solutions: a molecular dynamics study

We report the results of a molecular dynamics study of aqueous solutions of n-hydroxyethyl-trimethyl-ammonium chloride (choline chloride). An all-atom forcefield is developed for choline chloride, while the SPC/E model is used for water. The calculations predict densities that agree to within 1% of the values subsequently reported by the National Institute of Standards and Technology as part of the Industrial Fluid Properties Simulation Challenge. In addition to densities, other computed quantities include liquid structure and self-diffusivities.
Calibration and Error Analysis for Spectral Radiation Detectors

In every type of radiological monitoring, the fundamental goal is to relate the number of nuclear disintegrations observed in a detector to the concentration of radioactive elements actually present. The process of "calibrating" the detector is usually straightforward, but the uncertainties in the resulting calibration are often inadequately considered. Ignoring these uncertainties can produce an erroneous confidence in the calibration-dependent results, and consequently deficiencies in the data or in the data analysis can be missed. A technique using matrices for spectral data handling has been developed in which uncertainties originating in the input data are traced through the matrices to the final calculations. Uncertainties in the calculated concentrations are provided by a calibration matrix with an accompanying uncertainly matrix that relates countrate to radioelement concentrations. This analysis procedure was specifically developed for uranium and thorium exploration methods using radiation detectors equipped for spectral observations. In this application, the three elements potassium (K), uranium (U), and thorium (T) are of interest and the matrices have a 3×3 dimension. The method can be used directly for different sets of three radioelements, or it can be adapted to other dimensions.
DSCAM: A Novel Member of the Immunoglobulin Superfamily Maps in a Down Syndrome Region and is Involved in the Development of the Nervous System

Down syndrome (DS), a major cause of mental retardation, is characterized by subtle abnormalities of cortical neuroanatomy, neurochemistry and function. Recent work has shown that chromosome band 21q22 is critical for many of the neurological phenotypes of DS. A gene, DSCAM (Down syndrome cell adhesion molecule), has now been isolated from chromosome band 21q22.2-22.3. Homology searches indicate that the putative DSCAM protein is a novel member of the immunoglobulin (Ig) superfamily that represents a new class of neural cell adhesion molecules. The sequence of cDNAs indicates alternative splicing and predicts two protein isoforms, both containing 10 Ig-C2 domains, with nine at the N-terminus and the tenth located between domains 4 and 5 of the following array of six fibronectin III domains, with or without the following transmembrane and intracellular domains. Northern analyses reveals the transcripts of 9.7, 8.5 and 7.6 kb primarily in brain. These transcripts are differentially expressed in substructures of the adult brain. Tissue in situ hybridization analyses of a mouse homolog of the DSCAM gene revealed broad expression within the nervous system at the time of neuronal differentiation in the neural tube, cortex, hippocampus, medulla, spinal cord and most neural crest-derived tissues. Given its location on chromosome 21, its specific expression in the central nervous system and neural crest, and the homologies to molecules involved in neural migration, differentiation, and synaptic function, we propose that DSCAM is involved in neural differentiation and contributes to the central and peripheral nervous system defects in DS.
An unusual referral for epigastric pain, nausea, abdominal bloating, diarrhea, and weight loss.

Question: A 30-yearold woman with a past medical history of hypothyroidism presents for evaluation of epigastric discomfort, nausea without emesis, abdominal bloating, and watery, nonbloody diarrhea for 5 months. This was associated with a 15-pound weight loss. Complete blood count, liver function tests, thyroid-stimulating hormone, immunoglobulin (Ig) levels, and IgG/IgA tissue transglutaminase (tTG) were within normal limits. Stool studies for bacterial pathogens, giardia, Clostridium difficile toxin, and ova/ parasites were negative. An upper endoscopy revealed minimal antral erythema and abnormal duodenal bulb (Figure A) with a normal-appearing postbulbar duodenum (Figure B). Biopsies of the stomach, duodenal bulb, and second portion of the duodenum were obtained. What is the diagnosis? Look on page 1692 for the answer and see the GASTROENTEROLOGY web site (www.gastrojournal.org) for more information n submitting your favorite image to Clinical Challenges and Images in GI.
Activities of Benzimidazole d- and l-Ribonucleosides in Animal Models of Cytomegalovirus Infections

Since human cytomegalovirus (HCMV) does not infect or replicate in nonhuman cells and tissues, there are few animal models currently available for evaluation of antiviral therapies for these infections. In the present studies, we utilized two different models in which severe combined immunodeficient (SCID) mice were implanted with human fetal tissue that was subsequently infected with HCMV. In one model, human fetal retinal tissue was implanted into the anterior chamber of the SCID mouse eye, and in the second, human fetal thymus and liver (thy/liv) tissues were implanted under the kidney capsule. After the implants were established, they were infected with 2,000 to 9,000 PFU of HCMV. To determine the efficacy of three benzimidazole nucleosides, 2-bromo-5,6-dichloro-(1-β-d-ribofuranosyl)benzimidazole (BDCRB), GW275175X (175X), and GW257406X (1263W94, maribavir [MBV]) treatment was initiated 24 h after infection of the implants and continued for 28 days. Treatment consisted of either placebo, 25 mg of ganciclovir (GCV)/kg of body weight administered intraperitoneally (i.p.) twice daily, 33 or 100 mg of BDCRB/kg administered i.p. twice daily, or 75 mg of either MBV or 175X/kg administered orally twice daily. GCV was effective in both models, inhibiting HCMV infection by 5- to 3,000-fold. In the retinal tissue model, MBV and BDCRB reduced HCMV replication about fourfold through 21 days postinfection compared with results for the vehicle control. In the thy/liv tissue model, all three benzimidazole nucleosides were effective in inhibiting HCMV replication by approximately 30- to 3,000-fold in comparison to the vehicle control. These data indicate that the benzimidazole nucleosides were efficacious in these animal models and suggest that this class of compounds should be active against the various HCMV infections that occur in the immunocompromised host.
Ideal observer approximation using Bayesian classification neural networks

It is well understood that the optimal classification decision variable is the likelihood ratio or any monotonic transformation of the likelihood ratio. An automated classifier which maps from an input space to one of the likelihood ratio family of decision variables is an optimal classifier or "ideal observer." Artificial neural networks (ANNs) are frequently used as classifiers for many problems. In the limit of large training sample sizes, an ANN approximates a mapping function which is a monotonic transformation of the likelihood ratio, i.e., it estimates an ideal observer decision variable. A principal disadvantage of conventional ANNs is the potential over-parameterization of the mapping function which results in a poor approximation of an optimal mapping function for smaller training samples. Recently, Bayesian methods have been applied to ANNs in order to regularize training to improve the robustness of the classifier. The goal of training a Bayesian ANN with finite sample sizes is, as with unlimited data, to approximate the ideal observer. The authors have evaluated the accuracy of Bayesian ANN models of ideal observer decision variables as a function of the number of hidden units used, the signal-to-noise ratio of the data and the number of features or dimensionality of the data. The authors show that when enough training data are present, excess hidden units do not substantially degrade the accuracy of Bayesian ANNs. However, the minimum number of hidden units required to best model the optimal mapping function varies with the complexity of the data.
Selective unfolding of one Ribonuclease H domain of HIV reverse transcriptase is linked to homodimer formation

HIV-1 reverse transcriptase (RT), a critical enzyme 10 of the HIV life cycle and an important drug target, undergoes complex and largely uncharacterized conformational rearrangements that underlie its asymmetric folding, dimerization and subunit-selective ribonuclease H domain (RH) proteolysis. In the 15 present article we have used a combination of NMR spectroscopy, small angle X-ray scattering and X-ray crystallography to characterize the p51 and p66 monomers and the conformational maturation of the p66/p66 0 homodimer. The p66 monomer exists as a 20 loosely structured molecule in which the fingers/ palm/connection, thumb and RH substructures are connected by flexible (disordered) linking segments. The initially observed homodimer is asymmetric and includes two fully folded RH domains, while exhibiting 25 other conformational features similar to that of the RT heterodimer. The RH 0 domain of the p66 0 subunit undergoes selective unfolding with time constant ! 6.5 h, consistent with destabilization due to residue transfer to the polymerase 0 domain on the 30 p66 0 subunit. A simultaneous increase in the intensity of resonances near the random coil positions is characterized by a similar time constant. Consistent with the residue transfer hypothesis, a construct of the isolated RH domain lacking the two N-terminal 35 residues is shown to exhibit reduced stability. These results demonstrate that RH 0 unfolding is coupled to homodimer formation.
A phosphotyrosine displacement mechanism for activation of Src by PTPα

Protein tyrosine phosphatase α (PTPα) is believed to dephosphorylate physiologically the Src proto-oncogene at phosphotyrosine (pTyr)527, a critical negative-regulatory residue. It thereby activates Src, and PTPα overexpression neoplastically transforms NIH 3T3 cells. pTyr789 in PTPα is constitutively phosphorylated and binds Grb2, an interaction that may inhibit PTPα activity. We show here that this phosphorylation also specifically enables PTPα to dephosphorylate pTyr527. Tyr789→Phe mutation abrogates PTPα–Src binding, dephosphorylation of pTyr527 (although not of other substrates), and neoplastic transformation by overexpressed PTPα in vivo. We suggest that pTyr789 enables pTyr527 dephosphorylation by a pilot binding with the Src SH2 domain that displaces the intramolecular pTyr527–SH2 binding. Consistent with model predictions, we find that excess SH2 domains can disrupt PTPα–Src binding and can block PTPα-mediated dephosphorylation and activation in proportion to their affinity for pTyr789. Moreover, we show that, as predicted by the model, catalytically defective PTPα has reduced Src binding in vivo. The displacement mechanism provides another potential control point for physiological regulation of Src-family signal transduction pathways.