cssi/SciSciGPT-SciSciNet huggingface dataset:
Production of hollow microspheres for inertial confinement fusion experiments

The targets used in inertial confinement fusion (ICF) experiments at the Lawrence Livermore National Laboratory are plastic capsules roughly 0.5 mm in diameter. The capsules, which typically have wall thicknesses from 20 to 60 {mu}m, must possess extraordinary symmetry and concentricity and must have surface finishes of less than 1000 {Angstrom} peak-to-valley variation over surface contours of from 10 to 100`s of {mu}m. This paper reviews the fabrication of these capsules, focusing on the production of the thin-walled polystyrene microshell mandrel around which the capsule is built. The relationship between the capsule characteristics, especially surface finish, and capsule performance is discussed, as are the methods of surface characterization and modification necessary for experiments designed to study the effects of surface roughness on implosion dynamics. Targets for the next generation of ICF facilities using more powerful laser drivers will have to be larger while meeting the same or even more stringent symmetry and surface finish requirements. Some of the technologies for meeting these needs are discussed briefly.
Methods for studying recombination on chromosomes that undergo nondisjunction.

Abstract A lod score method is provided for mapping genes relative to the centromere using family data from autosomal trisomies. Such gene-centromere mapping can be performed whenever two or more members of a meiotic tetrad can be recovered. The critical mapping parameter is not the recombination value θ or the map distance w , but the probability of nonreduction y . In a disomic gamete arising by nondisjunction in a heterozygous host, the probability of heterozygosity (nonreduction) is 1 −y2 for a meiosis I error and y for a meiosis II error. Under various assumptions regarding chiasma interference, y can be related to θ and w . We provide specific methods for estimating y and θ from trisomy data using maximum likelihood, so that recombination may be studied on chromosomes that underwent nondisjunction.
Acoustoelectric interactions in acoustic-surface-wave devices

The principles of a wide range of acoustic-surface-wave devices employing acoustoelectric interactions with semiconductors are described. It is shown that acoustoelectric amplifiers can increase the dynamic range of a delay-line filter. Such devices have been operated on a CW basis and are beginning to become practical. The acoustic convolver and its derivative devices, the optical scanner, the acoustic focusing and imaging devices, and the storage correlator are described. Several of the signal processing applications of the convolver are discussed. Various types of constructional techniques, including the air gap convolver and acoustoelectric amplifier, the strip coupled and external diode convolvers, the use of piezoelectric semiconductors, deposition of a semiconductor on a piezoelectric substrate, and deposition of a piezoelectric material on a semiconducting substrate are discussed.
Phosphoamino acid analysis of protein immobilized on polyvinylidene difluoride membrane.

Abstract The direct analysis of phosphorylated proteins bound to polyvinylidene difluoride membrane (PVDFm) has been examined. Use of 14 C-methylated marker proteins demonstrated that proteins electroblotted on PVDFm were quantitatively retained through a series of test conditions, which included 1 m hydroxylamine (25°C, 30 min), 0.1 m NaOH (37°C, 30 min), 0.1 m HCl (55°C, 2 h), and 6 U/ml alkaline phosphatase (pH 9.5, 37°C, 24 h). Approximately half the protein remained bound following 2-h treatment in 1 m KOH (55°C). The same series of test conditions were employed to assess the stability of phosphorylated residues in 32 P-labeled protein immobilized on PVDFm, in order to assign them as carboxyl-,N-, or O-linked groups. The properties of phosphorylated proteins as determined by this method were comparable to the properties that have been reported for soluble proteins. Use of the PVDFm immobilization step affords simplification of the experimental procedures and permits rapid, quantitative sample recovery using submicrogram quantities of protein. Further, the PVDFm-bound phosphoproteins could be subjected to partial acid hydrolysis directly on the membrane and required no further purification for subsequent identification of the labeled phosphohydroxyamino acids. Definitive identification of labeled phosphoserine residues in histone, phosphoserine and phosphothreonine residues in myelin basic protein and insulin receptor, and phosphotyrosine residues in autophosphorylated insulin receptor was accomplished with as little as 0.2 nCi in about 50 ng of phosphorylated protein.
Comments on the Solution to the Boltzmann Equation for a Weakly Ionized Plasma

Hydrodynamic equations describing the motion of electrons in a weakly ionized plasma are derived formally from the Boltzmann equation by means of the Chapman-Enskog procedure. Two cases are considered, each with a stationary Maxwellian distribution ascribed to the atoms. In the first, electron-electron collisions are ignored, and the electron distribution function is determined by a balance between the electron-atom collisions and the electric field. There is only one conservation law, a hydrodynamic equation for the density. In the second case, electron-electron collisions are dominant, the distribution function is a local Maxwellian, and there are five conservation laws---equations for the density, drift velocity, and temperature. The equations used previously by the author to describe low-frequency oscillations are obtained in either case if the electron-atom collision frequency is independent of velocity. Otherwise, the zeroth-order equations are still exact, but first-order corrections are required, as illustrated by the example of the velocity-independent mean free path. Our results are somewhat different from those of Davidov, who made different assumptions about the dominant collision mechanisms.
Tumour necrosis factor α induces co-ordinated activation of rat GSH synthetic enzymes via nuclear factor κB and activator protein-1

GSH synthesis occurs via two enzymatic steps catalysed by GCL [glutamate-cysteine ligase, made up of GCLC (GCL catalytic subunit), and GCLM (GCL modifier subunit)] and GSS (GSH synthetase). Co-ordinated up-regulation of GCL and GSS further enhances GSH synthetic capacity. The present study examined whether TNFalpha (tumour necrosis factor alpha) influences the expression of rat GSH synthetic enzymes. To facilitate transcriptional studies of the rat GCLM, we cloned its 1.8 kb 5'-flanking region. TNFalpha induces the expression and recombinant promoter activities of GCLC, GCLM and GSS in H4IIE cells. TNFalpha induces NF-kappaB (nuclear factor kappaB) and AP-1 (activator protein 1) nuclear-binding activities. Blocking AP-1 with dominant negative c-Jun or NF-kappaB with IkappaBSR (IkappaB super-repressor, where IkappaB stands for inhibitory kappaB) lowered basal expression and inhibited the TNFalpha-mediated increase in mRNA levels of all three genes. While all three genes have multiple AP-1-binding sites, only GCLC has a NF-kappaB-binding site. Overexpression with p50 or p65 increased c-Jun mRNA levels, c-Jun-dependent promoter activity and the promoter activity of GCLM and GSS. Blocking NF-kappaB also lowered basal c-Jun expression and blunted the TNFalpha-mediated increase in c-Jun mRNA levels. TNFalpha treatment resulted in increased c-Jun and Nrf2 (nuclear factor erythroid 2-related factor 2) nuclear binding to the antioxidant response element of the rat GCLM and if this was prevented, TNFalpha no longer induced the GCLM promoter activity. In conclusion, both c-Jun and NF-kappaB are required for basal and TNFalpha-mediated induction of GSH synthetic enzymes in H4IIE cells. While NF-kappaB may exert a direct effect on the GCLC promoter, it induces the GCLM and GSS promoters indirectly via c-Jun.
The properties and origin of the proteins in the SV40 nucleoprotein complex.

Abstract Infection of African green monkey kidney cells with simian virus 40 (SV40) results in the formation of an SV40 specific DNA-protein complex that sediments at about 50 S (Green et al. , 1971 ; White and Eason, 1971) . This nucleoprotein complex has been fixed with formaldehyde and the DNA to protein ratio was estimated from its buoyant density in CsCl equilibrium density gradients. Most of the complex (>95%) had a buoyant density of 1.47 g/cc while a minor fraction ( M NaCl, while above this ionic strength the protein to DNA ratio decreases. One or two viral coat proteins, determined by SV40 temperature-sensitive mutants tsB8 and tsB11, were found to be associated with the 50 S nucleoprotein complex. Evidence for a third tightly bound protein is also presented.
On the Nonlinear Behavior of a Glass-Ceramic Seal and Its Application in Planar SOFC Systems

This paper studies the nonlinear behavior of a glass-ceramic seal used in planar solid oxide fuel cells (SOFCs). To this end, a viscoelastic damage model has been developed that can capture the nonlinear material response due to both progressive damage in the glass-ceramic material and viscous flow of the residual glass in this material. The model has been implemented in the MSC MARC finite element code, and its validation has been carried out using the experimental relaxation test data obtained for this material at 700oC, 750oC, and 800oC. Finally, it has been applied to the simulation of a SOFC stack under thermal cycling conditions. The areas of potential damage have been predicted.
A Theory of Strongly Continuous Semigroups in Terms of Lie Generators

LetXdenote a complete separable metric space, and let C(X) denote the linear space of all bounded continuous real-valued functions onX. A semigroupTof transformations fromXintoXis said to be jointly continuous if the mapping (t, x)→T(t) xis jointly continuous from [0, ∞)×XintoX. The Lie generator of such a semigroupTis the linear operator in C(X) consisting of all ordered pairs (f, g) such thatf, g∈C(X), and for eachx∈X, g(x) is the derivative at 0 off(T(·) x). We completely characterize such Lie generators and establish the canonical exponential formula for the original semigroup in terms of powers of resolvents of its Lie generator. The only topological notions needed in the characterization are two notions of sequential convergence, pointwise and strict. A sequence in C(X) converges strictly if the sequence is uniformly bounded in the supremum norm and converges uniformly on compact subsets ofX.
A grain level model for the study of failure initiation and evolution in polycrystalline brittle materials. Part I: Theory and numerical implementation

Abstract A model is presented to analyze material microstructures subjected to quasi-static and dynamic loading. A representative volume element (RVE) composed of a set of grains is analyzed with special consideration to the size distribution, morphology, chemical phases, and presence and location of initial defects. Stochastic effects are considered in relation to grain boundary strength and toughness. Thermo-mechanical coupling is included in the model so that the evolution of stress induced microcracking, from the material fabrication stage, can be captured. Intergranular cracking is modeled by means of interface cohesive laws motivated by the physics of breaking of atomic bonds or grain boundary sliding by atomic diffusion. Several cohesive laws are presented and their advantages in numerical simulations are discussed. In particular, cohesive laws simulating grain boundary cracking and sliding, or shearing, are proposed. The equations governing the problem, as well as their computer implementation, are presented with special emphasis on selection of cohesive law parameters and time step used in the integration procedure. This feature is very important to avoid spurious effects, such as the addition of artificial flexibility in the computational cell. We illustrate this feature through simulations of alumina microstructures reported in part II of this work. A technique for quantifying microcrack density, which can be used in the formulation of continuum micromechanical models, is addressed in this analysis. The density is assessed spatially and temporally to account for damage anisotropy and evolution. Although this feature has not been fully exploited yet, with the continuous development of cheaper and more powerful parallel computers, the model is expected to be particularly relevant to those interested in developing new heterogeneous materials and their constitutive modeling. Stochastic effects and other material design variables, although difficult and expensive to obtain experimentally, will be easily assessed numerically by Monte Carlo grain level simulations. In particular, extension to three-dimensional simulations of RVEs will become feasible.
Follow-up on hang gliding injuries in Colorado.

In a period extending from July 1973 to December 1975, seven fatal hang glider accidents were recorded in Colorado, all among experienced pilots. In addition, 11 serious nonfatal injuries were reported, which may represent only a fraction of those occurring. Accidents were noted to be multifactorial, caused by (1) pilot error, (2) equipment failure, (3) terrain hazards, and (4) possible design shortcomings. Accidents can be expected to decline in frequency with improved pilot training programs, grading and regulation of sites, and standardized safety clothing. No doubt over time, the less safe standard Rogallo wing will be replaced by the more stable Superkites and controlled collapsibles, which offer a higher safety margin. In the last analysis, this sport will remain a popular yet high risk endeavor (Figs. 2 through 5). Language: en
Autoregressive models for compressing similar data

The paper studies the use of common autoregressive models for a similar database compression and estimates compression ratio for predictive models based on correlation coefficient.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Primary Charge-Separation Rate at 5 K in Isolated Photosystem II Reaction Centers Containing Five and Six Chlorophyll a Molecules

Although the primary charge-separation rate in the photosystem II (PSII) reaction center (RC) has been the subject of many time- and frequency-domain experiments, its value is still an unsettled issue, especially at or near room temperature. As a first step toward understanding its temperature dependence, it is important to have a reliable value for the rate at liquid helium temperatures. Presented are results from triplet bottleneck hole-burning (TBHB) experiments at 5.0 K on RCs isolated from spinach that contain either six or five chlorophyll a (Chl) molecules per two pheophytin (Pheo) molecules (referred to as RC-6 and RC-5). RC-5 possesses only one of the two peripheral Chls of the RC. The triplet state that serves as the population bottleneck is formed by charge recombination of the radical ion pair P680 + Pheo1- , where P680 is the primary electron donor and Pheo1 is the acceptor on the active (D1) branch. In the TBHB experiments, the laser burn intensity was varied over 2 orders of magnitude to as...
Midterm outcomes of the Zenith Renu AAA Ancillary Graft

Objective The Zenith Renu abdominal aortic aneurysm (AAA) Ancillary Graft (Cook Medical Inc, Bloomington, Ind) provides active proximal fixation for treatment of pre-existing endografts with failed or failing proximal fixation or seal. The purpose of this study was to evaluate the midterm outcomes of treatment with this device. Methods From September 2005 to November 2006, a prospective, nonrandomized, multicenter, postmarket registry was utilized to collect physician experiences from 151 cases (89 converters and 62 main body extensions) at 95 institutions. Preoperative indications and procedural and postimplantation outcomes were collected and analyzed. Technical success and clinical success were determined as defined by the Society of Vascular Surgery reporting standards. Results Patients were predominantly male (87%) with a mean age of 77 years. The interval between the original endograft implantation to Renu treatment was 43.4 ± 18.7 months. The indications for treatment were endoleak (n = 111), migration (n = 136), or both (n = 94). Technical success was 98.0% with two cases of intraoperative conversion and one case of persistent type IA endoleak. The median follow-up for the cohort was 45.0 months (range, 0-56 months; interquartile range, 25.0 months). Overall, 32 cases had treatment failures that included at least one of the following: death (n = 5), type I/III endoleak (n = 18), graft infection (n = 1), thrombosis (n = 1), aneurysm enlargement >5 mm (n = 9), rupture (n = 4), conversion (n = 9, with 7 after 30 days), and migration (n = 1). Overall, the clinical success for the entire cohort during the follow-up period was 78.8% (119/151). Conclusions The postmarket registry data confirm that the Zenith Renu AAA Ancillary Graft can be used to treat endovascular repairs that failed due to proximal attachment failures. The salvage treatment with the Renu device had high technical success rate and resulted in clinical success in a majority of patients (78.8%). While failed endovascular repairs can be salvaged, a clinical failure in one of five patients still emphasizes the importance of patient and device selection during initial endovascular aneurysm repair to ensure durable success.
Increasing incidence of differentiated thyroid cancer in the United States, 1988–2005

BACKGROUND: Studies have reported an increasing incidence of thyroid cancer since 1980. One possible explanation for this trend is increased detection through more widespread and aggressive use of ultrasound and image-guided biopsy. Increases resulting from increased detection are most likely to involve small primary tumors rather than larger tumors, which often present as palpable thyroid masses. The objective of the current study was to investigate the trends in increasing incidence of differentiated (papillary and follicular) thyroid cancer by size, age, race, and sex. METHODS: Cases of differentiated thyroid cancer (1988-2005) were analyzed using the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) dataset. Trends in incidence rates of papillary and follicular cancer, race, age, sex, primary tumor size ( 4 cm), and SEER stage (localized, regional, distant) were analyzed using joinpoint regression and reported as the annual percentage change (APC). RESULTS: Incidence rates increased for all sizes of tumors. Among men and women of all ages, the highest rate of increase was for primary tumors <1.0 cm among men (1997-2005: APC, 9.9) and women (1988-2005: APC, 8.6). Trends were similar between whites and blacks. Significant increases also were observed for tumors ≥4 cm among men (1988-2005: APC, 3.7) and women (1988-2005: APC, 5.70) and for distant SEER stage disease among men (APC, 3.7) and women (APC, 2.3). CONCLUSIONS: The incidence rates of differentiated thyroid cancers of all sizes increased between 1988 and 2005 in both men and women. The increased incidence across all tumor sizes suggested that increased diagnostic scrutiny is not the sole explanation. Other explanations, including environmental influences and molecular pathways, should be investigated. Cancer 2009. © 2009 American Cancer Society.
Human Colonization and Late Pleistocene Lithic Industries of the Americas

Abstract The lithic record of human colonization of the Americas is sparse, scattered and ambiguous. Working outward from Clovis in time and space, I summarize and critique assemblage and distributional studies from the dual perspective of assemblage-formation and general theory. An alternative is to seek historical signals residing in fluted points that may be deciphered using new, especially morphometric, methods, and especially in continuous traits. New data always are useful, but the most urgent requirement for progress in colonization research is improved theory and practice. However Clovis originated, in the near future the most productive research may be on what it became.
A scheduling problem: modeling, approximate algorithms, and implementation

Beginning students tend to think that computer science means only programming. As teachers of computer science, we are constantly trying to emphasize that the important component of computer science is a problem solving ability. This is not easy for several reasons. First of all, it is difficult to “teach” problem solving, whether in the context of computer science or not. Secondly, beginning computer students spend the vast majority of their time struggling to get this program working just before the deadline so that they can then start on the next program. A third reason that students might miss the problem solving focus is that we don't give them enough opportunities to solve problems from start to finish. All too often these programming assignments are presented to the students in a “ready-to-program” format. That is, the real work is glossed over or is accomplished for them. In this paper we discuss a simple but important application, committee scheduling. This problem is an excellent example of the entire problem solving process and provides students at all levels with the opportunity to formulate a mathematical model, prove a theorem, consider alternate strategies for implementing a solution as a computer algorithm, and perform some elementary algorithm analysis.
What is Useful Life for White Light LEDs

(2001). What is Useful Life for White Light LEDs? Journal of the Illuminating Engineering Society: Vol. 30, No. 1, pp. 57-67.
Gate Dielectric Chemical Structure−Organic Field-Effect Transistor Performance Correlations for Electron, Hole, and Ambipolar Organic Semiconductors

This study describes a general approach for probing semiconductor−dielectric interfacial chemistry effects on organic field-effect transistor performance parameters using bilayer gate dielectrics. Organic semiconductors exhibiting p-/n-type or ambipolar majority charge transport are grown on six different bilayer dielectric structures consisting of various spin-coated polymers/HMDS on 300 nm SiO2/p+-Si, and are characterized by AFM, SEM, and WAXRD, followed by transistor electrical characterization. In the case of air-sensitive (generally high LUMO energy) n-type semiconductors, dielectric surface modifications induce large variations in the corresponding OTFT performance parameters although the film morphologies and microstructures remain similar. In marked contrast, the device performance of air-stable n-type and p-type semiconductors is not significantly affected by the same dielectric surface modifications. Among the bilayer dielectric structures examined, nonpolar polystyrene coatings on SiO2 having ...
Receptors for insulin and epidermal growth factor: relation to synthesis of DNA in cultured rabbit lens epithelium.

Abstract Epidermal growth factor (EG factor) and insulin stimulate the incorporation of thymidine into contact-inhibited rabbit lens epithelial cells in culture. The maximal stimulation observed with EG factor is greater than with insulin. Half-maximal stimulation by EG factor is observed at 6 × 10 −10 m and for insulin at 1 × 10 −9 m . [ 125 I]-labeled EG factor (2000 Ci/mmol, about 1 g atom of iodine per mol) is equipotent with native EG factor in stimulating DNA synthesis. Both insulin and EG factor bind to distinct high-affinity sites in intact lens cell monolayers; half-maximal binding is observed at about 10 −9 m for both polypeptides. A maximum of approximately 8 × 10 4 insulin molecules and 4 × 10 4 EG factor molecules are bound per cell. These observations indicate that cultured rabbit lens cells possess receptors for insulin and EG factor by biological and physicochemical criteria and raise the possibility that both peptides may play a role in lens growth and development.
How Much Time Do Physicians Spend Providing Care Outside of Office Visits

Much primary care takes place outside of the office and is not reimbursed. Farber and associates collected information on clinical interactions outside of office visits in an academic geriatric med...
Results after transplantation using donor hearts with preexisting coronary artery disease.

Abstract Objective Cardiac allografts with coronary artery disease may permit a selective expansion of the donor pool. Twenty-two recipients who received donor hearts with mild to moderate coronary artery disease on angiography were reviewed. All donor organs had preserved left ventricle function on echocardiogram. Methods The procedure was explained to the patients in detail. All survivors have at least 1 year of follow-up. If the coronary arteries of the donor heart were significantly occluded, then the implanting surgeon performed coronary revascularization. Donors were allocated to patients facing imminent death (group I, n=4) or to those who would otherwise not have been transplanted (group II, n=18). Median recipient age was 57 years old for group I and 68 years old for group II. Median follow-up was 25 months for group I and 44 for group II. Results Outcome was evaluated using survival and freedom from graft coronary disease as end points. In group I, 3 of the 4 hearts required revascularization. In group II, 10 of the 18 required revascularization. The majority of the revascularizations were recipient saphenous vein grafts (84.6%) to the donor left anterior descending artery (50%). The 1-month and 2-year actual survivals for group I are 75% and 50% and 87.5% and 81.3 for group II. One patient in group I who was in extremis and 3 in group II died at less than 90 days. Group II early deaths had donor risk factor combinations of coronary artery disease, left ventricular hypertrophy, and long distance. Freedom from new graft coronary artery disease was 100% at 2 years in group I and 87.5% in group II. Conclusions Selective use of donor hearts with coronary artery disease is acceptable. Early deaths are related to recipient factors as well as associated donor risk factors. Donor hearts with mild or moderate coronary artery disease and preserved function on echocardiogram can be used but may require revascularization with recipient conduit and/or percutaneous transluminal coronary artery angioplasty. Coronary disease in donor hearts requires grading and does not categorically preclude use, particularly in risk-matched recipients.
Maximum number of edges joining vertices on a cube

Let Ed(n) be the number of edges joining vertices from a set of n vertices on a d-dimensional cube, maximized over all such sets. We show that Ed(n) = Σi=0r-1 (li/2+i)2li, where r and l0 > l1 > ... > lr-1 are nonnegative integers defined by n= Σi=0r-12li.
Hybrid methods of chemical-shift imaging.

We propose a family of hybrid chemical-shift sequences which combines two physical principles for water/lipid separation to minimize artifacts introduced by B0 and B1 inho-mogeneities. Hybrid sequences provide improved species discrimination over earlier methods without resorting to postprocessing while maintaining a multislice/multiecho capability. © 1989 Academic Press, Inc.
Quantitation of serum retinol-binding protein by an enzyme-linked immunosorbent assay

Abstract An enzyme-linked immunosorbent technique for human serum retinol-binding protein (RBP) was developed. The assay detects RBP via a double-antibody (rabbit anti-human RBP) sandwich technique. The antibody is immobilized by passive adsorption to a polystyrene tube; the assay is then carried out by successive additions containing known and unknown amounts of RBP (antigen), alkaline phosphatase linked to the same antibody, and p -nitrophenyl phosphate (substrate). Colorimetric analysis of the hydrolysis of the substrate by the enzyme (indirectly) attached to the antigen is used for RBP quantitation. The intra- and interassay coefficients of variation ranged between 4 and 7 and 9 and 12%, respectively. The assay can be performed in less than 7 h and has a sensitivity in the nanogram range (3–48 ng/ml). RBP content was analyzed in serum and urine samples of 20 healthy donors and 17 patients with renal failure and in 20 serum specimens of patients with liver cirrhosis. Renal patients had higher serum (mean 150, range 50–398 μg/ml) and urine RBP levels (mean 14, range 1–80 μg/ml) than normal donors (mean serum 43, range 30–60 μg/ml; mean urine RBP 0.06, range 0.04 – 0.13 μg/ml). Liver disease patients had lower than normal serum RBP values (mean 22, range 10–43 μg/ml).
Saccharopine cleavage by a dehydrogenase of human liver.

Abstract An enzyme catalyzing the cleavage of saccharopine ( e-N-( l -glutaryl-2)- l -lysine ) has been purified 120-fold from human liver. The enzyme, ( e-N-( l -glutaryl-2)- l -lysine:NAD + oxidoreductase ( l -2-aminoadipic-δ-semialdehyde and glutamate forming)) was purified by procedures which included (NH4)2SO4 precipitation and chromatography on a DEAE-cellulose column. The enzyme has a pH optimum of pH 8.8–9.0 and exhibits at least 50% of optimal activity between pH 7.8 and 9.7. The Michaelis constants for saccharopine and NAD+ are 5.10−4 M and 4.10−4 M, respectively. While the crude enzyme appears to be stable at −20°, the purified fraction loses virtually all of its activity within 3 weeks. At 2°, the purified fraction loses 5–10% of its activity per week. Incubation of the purified enzyme with [glutaryl-14C5]saccharopine resulted in the stoichiometric reduction of NAD+ with the stoichiometric production of [14C]glutamate.
WSN13-2: Scalable OSPF Updates for MANETs

Recently, mobile ad hoc networks (MANETs) have evolved as an irreplaceable networking technology for situations with sparse or inexistent infrastructure. Adapting OSPFv3 to MANET environments has several advantages. The protocol has proven its maturity in the wired Internet and is now the de facto standard Intra-AS routing protocol. When used in wireless ad hoc networks with proper extensions, OSPFv3 can provide better interoperation between the ad hoc domain and the Internet. This is one of the essential requirements for any ad hoc networks (including wireless mesh networks) that require connectivity to the Internet. The main challenge is that since OSPF is highly optimized for wired-oriented environment, it needs further enhancement to be fully functional in ad hoc scenarios. The most serious obstacle is the large routing overhead associated with the frequent topology changes due to volatile wireless links and node mobility. Various overhead reduction schemes have been proposed by focusing on how to reduce hello packets, flooding nodes, or the number of adjacencies. We propose a completely different approach by taking into account the very essential characteristics of wireless ad hoc networks - namely, distance effect. We implemented the proposed scheme on a simulator that uses the real OSPFv3 as its routing module. The simulation experiments prove that the proposed scheme allows significant reduction in OSPF routing overhead at small loss of route optimality.
New Retinal Detachment after Pneumatic Retinopexy

Thirteen cases of rhegmatogenous retinal detachment repaired by pneumatic retinopexy were reviewed retrospectively. All patients were followed for a minimum of 6 months after surgery. At the end of follow-up, retinal detachment repair by pneumatic retinopexy succeeded in nine cases (70%) and failed in four (30%). Within 2 days of pneumatic retinopexy, vitreous condensation and traction with new retinal tears and associated detachments in previously uninvolved quadrants developed in two patients. The occurrence of new retinal detachments in the early postoperative period after pneumatic retinopexy has not been previously observed.
Web-Enhanced General Chemistry Increases Student Completion Rates, Success, and Satisfaction

General Chemistry I historically had one of the highest failure and withdrawal rates at Penn State Berks, a four-year college within the Penn State system. The course was completely redesigned to incorporate more group work, the use of classroom response systems, peer mentors, and a stronger online presence via the learning management system (ANGEL). Five years of data about the redesigned course were compared with the previous five years. The redesigned course significantly improved student success as measured by the average GPA and lower withdrawal rates. Student achievement in the subsequent course, General Chemistry II, has also improved, suggesting that not only are more students completing the first course, but they are also completing the course with better preparation for the next course. Student ratings have improved for the course, showing increased satisfaction with both the course and the instructor. The findings from 10 years of data suggest significant improvements in student success are possible for General Chemistry I.
Attacks on neonates by a male mangabey (Cercocebus atys)

Aggressive behavior by an adult male toward selected infants and their mothers was observed during a long-term study of reproduction in a captive social group of sooty mangabeys (Cercocebus atys). The highest-ranking adult male in this group was observed to attack and bite three neonates out of a total of 13 infants born in 1982. All three attacks were directed attacks in which infants were grabbed from their mothers and bitten in the head. The first infant was fatally injured; the other two probably would have sustained fatal wounds had the male's canines not been blunted beforehand and had observers not intervened. The attacks were preceded by a pattern in which the male persistently stalked or chased the mother-infant pairs, a behavior first observed in the hours immediately following parturition. Unlike attacks in wild baboon groups following male immigration, these attacks on infants occurred in a stable social group in which the male attacker had been a lifelong resident. This male, however, had gained alpha rank only 3 months before attacking the first infant. These attacks, in the context of other evidence of aggression and wounding, are discussed relative to current models of infanticide in primates.
Phosphorylation of Glial Fibrillary Acidic Protein and Vimentin by Cytoskeletal-Associated Intermediate Filament Protein Kinase Activity in Astrocytes

: These studies describe a cytoskeletal-associated protein kinase activity in astrocytes that phosphorylated the intermediate filament proteins glial fibrillary acidic protein (GFAP) and vimentin and that appeared to be distinct from protein kinase C (PK-C) and the cyclic AMP-dependent protein kinase (PK-A). The cytoskeletal-associated kinase activity phosphorylated intermediate filament proteins in the presence of 10 mMMgCl2 and produced an even greater increase in 32P incorporation into these proteins in the presence of calcium/calmodulin. Tryptic peptide mapping of phosphorylated intermediate filament proteins showed that the intermediate filament protein kinase activity produced unique phosphopeptide maps, in both the presence and the absence of calcium/calmodulin, as compared to that of PK-C and PK-A, although there were some common sites of phosphorylation among the kinases. In addition, it was determined that the intermediate filament protein kinase activity phosphorylated both serine and threonine residues of the intermediate filament proteins, vimentin and GFAP. However, the relative proportion of serine and threonine residues phosphorylated varied depending on the presence or absence of calcium/calmodulin. The magnesium-dependent activity produced the highest proportion of threonine phosphorylation, suggesting that the calcium/calmodulin-dependent kinase activity acts mainly at serine residues. PK-A and PK-C phosphorylated mainly serine residues. Also, the intermediate filament protein kinase activity phosphorylated both the N-and the C-terminal domains of vimentin and the N-terminal domain of GFAP. In contrast, both PK-C and PK-A are known to phosphorylate the N-terminal domains of both proteins. The intermediate filament protein kinase activity appeared to be distinct from that of PK-C and PK-A and was able to phosphorylate unique sites of intermediate filament proteins. Also, it appeared that the intermediate filament protein kinase activity represents two kinases: a magnesium-dependent protein kinase and a calcium/calmodulin-dependent protein kinase.
Thermomechanics of the shape memory effect in polymers for biomedical applications

We examine the shape memory effect in polymer networks intended for biomedical, and specifically cardiovascular, applications. The polymers were synthesized by photopolymerization from a tert-butyl acrylate monomer with a diethyleneglycol diacrylate crosslinker. Three-point flexural tests were used to systematically investigate the thermomechanics of shape storage (predeformation) and shape recovery. The glass transition temperature, T(g), of the polymers was determined to be approximately 65 degrees C. The polymers show 100% strain recovery, at low and high predeformation temperatures, up to maximum strains of approximately 80%. The polymers show a sigmoidal free strain recovery response as a function of increasing temperature at a constant heating rate. Free strain recovery was determined to depend on the temperature during predeformation; lower predeformation temperatures (T T(g)) is sigmoidal. The isothermal free strain recovery rate was found to increase with increasing temperature or decreasing predeformation temperature. The thermomechanical results are discussed in light of potential biomedical applications, and a prototype device is presented.
Ultraviolet radiation exposure in children: a review of measurement strategies.

Rates of skin cancer in the U.S. are high and have been increasing rapidly. Recommendations for primary prevention focus on the reduction of ultraviolet radiation (UVR) exposure, especially in childhood. Valid, reliable strategies are needed to measure UVR exposure in children, to document baseline levels, and to assess intervention impact. This article reviews strategies reported in observational and intervention studies and considers their potential usefulness for application with children. The strategies include verbal report (by self or parent), direct observation, visual inspection, ultraviolet (UV) sensitive film, the Erythema Meter, the spectrophotometer, and the colorimeter. Each strategy is described along several dimensions, including ease of use, cost, and whether it is suitable for measuring acute and cumulative exposure. The review describes the existing validity and reliability data and points out a need for further research assessing the reliability and validity of most of these measures. Additionally, suggestions for matching strategies with measurement and intervention objectives are presented.
Binary arithmetic using optical symbolic substitution and integrated phototransistor surface-emitting laser logic

We outline an architecture for performing binary addition by using optical symbolic substitution and optical logic gates based on heterojunction phototransistors and vertical-cavity surface-emitting lasers.
Energy and Depletable Resources: Economics and Policy, 1973–1998☆

Abstract This paper reviews the impact of the literature in depletable resources and energy economics over the period 1973–1998, particularly the initial period of publication of the Journal of Environmental Economics and Management, 1974–1998. A discussion of prominent policy issues in this arena is provided, along with an indication of what academic economics papers have contributed to that debate. This is followed by a citation analysis of contributions in the fields of energy and exhaustible resource economics. For each of these two fields, a list of the top papers in each five-year period from 1974 to 1998 is presented, along with a list of the top journals in each decade, based on average citations per article. The top ten cited articles in the fields in the Journal of Environmental Economics and Management are also presented.
Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska

U-Th-Pb analyses of zircons from an ortho-augen gneiss body in the Yukon-Tanana Upland of east-central Alaska yield strong evidence for the presence of early Proterozoic material in this area. U-Pb data define a chord that intersects concordia at about 2,300 and 345 m.y. We consider two interpretations: (1) the protolith was intruded during the Proterozoic and was subsequently metamorphosed in the Paleozoic or, more likely, (2) the protolith was intruded in the Paleozoic and incorporated material of Proterozoic age. An Sm-Nd model age of about 1,900 m.y. on a whole-rock sample of augen gneiss is additional evidence for the presence of Proterozoic material in the gneiss. K-Ar and U-Th-Pb dating of mica and sphene, respectively, reveal that younger thermal events occurred at least as recently as 110 m.y. ago.
Modeling fluid flow and transport in variably saturated porous media with the STOMP simulator. 1. Nonvolatile three-phase model description

Abstract STOMP is a multipurpose engineering simulator for investigating remediation technologies for the cleanup of organic compounds and associated radionuclides within the soil and groundwater in the arid and semiarid western United States. Fundamentally, the simulator numerically solves flow and transport through variably saturated geologic media using an integrated-volume finite-difference scheme to discretize the governing conservation equations. Modeling capabilities include those for multiple phases, compositional NAPL, and nonisothermal conditions using a variable configuration source code to apportion execution speed and memory requirements to the problem specifics. This paper presents a brief overview of the entire simulator and then focuses on solution techniques for solving problems involving nonvolatile three-phase systems with hysteretic, fluid entrapment, and nonhysteretic forms of the saturation-relative permeability-capillary pressure relations. The solution techniques concentrate on developed algorithms for phase-transitions, which are demonstrated for a hypothetical problem involving NAPL appearances and disappearances. Mass-balance errors for these simulations were less than 0·06%. In a companion paper, saturations computed from simulations using STOMP are compared against experimental data for two one-dimensional, nonvolatile three-phase flow systems.
EFFECTS OF MIGRATORY GRAZERS ON SPATIAL HETEROGENEITY OF SOIL NITROGEN PROPERTIES IN A GRASSLAND ECOSYSTEM

Large herbivores are known to respond to spatial heterogeneity in the distribution of forage resources, but how important herbivores are in creating those spatial patterns, how their influence may be scale dependent, and how herbivore-induced patterns affect ecosystem processes remain unclear. We examined the effects of native migratory ungulates on the spatial distribution of soil nitrogen and N-mineralization potential at scales ranging from 0.1–30 m in grasslands of Yellowstone National Park using geostatistical analyses of soils collected inside and outside long-term (36+-yr) exclosures. At small spatial scales (0.1–2 m), ungrazed grasslands showed a high degree of patchiness in the distribution of soil N and N-mineralization potential (94% and 77% of sample variation explained by small-scale patchiness, respectively). For both variables, patches occurred at a consistent mean size of ∼40 cm. In contrast, grazed grassland exhibited minimal spatial structure in the distribution of soil N and N-mineralization rates (<24% of variation for both variables spatially dependent) and no consistent patch size at a scale of 0.1–2 m. In grazed grassland, most variation was extremely fine grained, occurring across distances <10 cm. The high degree of fine-grained heterogeneity in grazed grassland was associated with greater plant diversity in small (20 × 20 cm) patches. Recycling of nitrogen through dung and urine is clearly important for maintaining long-term nitrogen balance of the system, but we estimated that only 2.5% of the grazed grassland sampled was recently affected by urine. Results conflict with predictions of increased heterogeneity in grazed communities based primarily on the deposition of dung and urine in discrete patches and suggest that the dominant mechanism(s) by which grazers alter N cycling in this ecosystem operates through the plant community. We hypothesize that grazers promote fine-scale heterogeneity by diversifying plant species effects on soils and/or increasing the spatial variability in plant litter inputs. At larger spatial scales (5–30 m), large herbivores altered the distribution of soil N across a topographic gradient. In a grazed community, soil N properties were associated with the topographic gradient and exhibited increasing variance among sampling points separated by increasing distances from 5 to 30 m. Ungrazed grassland exhibited no spatial structure in soil N distribution and no correlation with topography. Collectively, our data show that grazers influence the distribution of soil N properties at every spatial scale from individual plants to landscapes.
Professor Donald Johnson’s list of Landmark Papers (1878–1998) in geomorphology and soil geomorphology – an appreciation

This paper provides the complete list of papers that were read and discussed in graduate seminars run in 1998 and 2001 by Professor Donald Johnson of the University of Illinois. A literature sleuth...
Effects of ethane dimethanesulfonate (EDS) on adult and immature rabbit Leydig cells: comparison with EDS-treated rat Leydig cells.

Ethane-dimethanesulfonate (EDS) has been shown to selectively kill Leydig cells and depress testosterone production in adult rats. A recent study has shown that immature rat Leydig cells are less sensitive to EDS exposure. There is evidence that the rabbit metabolizes EDS to methane sulfonic acid more rapidly than does the rat, reducing exposure to the parent compound. In the study reported here, we examined the effects of EDS on the Leydig cells in both adult and immature rabbits and compared the effects found with those previously reported in the rat. In vivo, EDS exposure demonstrated that Leydig cells from adult rabbits were affected, with both serum and interstitial testosterone production depressed. EDS effects in adult rabbits and rats were compared by exposing explants of testicular parenchyma to EDS in vitro and evaluating testosterone production. With this procedure, the rabbit testis was less sensitive to EDS treatment than the rat, with a 50% reduction rate (EC5 0 ) achieved with 2026 ItM EDS for the rabbit and with 336 tIM EDS for the rat. Perfusion of adult and immature rabbit testis with 430 M EDS demonstrated the insensitivity of the immature testis to EDS exposure: adult testosterone production was reduced 50% in 3.5 h, whereas no diminution was found in the immature rabbit. EDS exposure of interstitial cell preparations further demonstrated the insensitivity of immature rabbit Leydig cells, with an EC50 of 4397 FLM compared to an EC5, of 1137 ptM EDS in adult preparations. These and previously reported data in the rat provide evidence for the following order in Leydig cell sensitivity to EDS exposure: adult rat > adult rabbit > immature rat >> immature rabbit.