cssi/SciSciGPT-SciSciNet huggingface dataset:
Small-Scale Wind Energy Harvesting From Flow-Induced Vibrations

Significant wind energy exists in the boundary layers around naturally occurring and manmade structures. This energy source has remained largely untapped, even though it presents a significant source of energy for powering wireless devices in built-up areas. This paper discusses a study on harnessing energy from piezoelectric transducers by using bluff body and vortex-induced vibration phenomena induced by low-speed flows. The proposed devices are miniature, scalable, aeroelastic wind harvesters designed for extracting turbulent, low-speed wind energy from the boundary layers around structures. The design configuration consists of a bluff body with a flexible piezoelectric cantilever attached to the trailing edge. In this design, transverse vibrations are induced in the piezoelectric members by alternating vortex shedding. The multi-physics software package COMSOL is used for coupled simulation of the fluid and structural domains, and Matlab is used to couple the structural deformations to the attached power harvesting circuitry. The design and environmental parameters are varied to optimize the configuration and to identify the significant parameters in the design. The lock-in phenomenon, in which the vortex shedding frequency is entrained to the fundamental structural frequency, is exploited to achieve resonance over a range of flow velocities, thus increasing the velocity “bandwidth” of the devices. Simulations are run for different characteristic dimensions or shapes for the bluff body to study the strength and nature of vortex shedding in the presence of vibrating beam sections. The results of parameter variation for the design configuration is presented and discussed with regard to broadband wind energy harvesting.Copyright © 2011 by ASME
Ion beam system for the new high current ion implantation system Extrion-1000

Abstract To meet the challenging performance requirements of next generation high current ion implanters, several new technologies have been developed for the ion beam system of the new Varian high current ion implanter, Extrion-1000. A novel strong focussing accel/decel scheme with a new ion source guarantees high beam output even down to very low energies. Its multiple crucible vaporizer is based on a new concept and allows easy maintenance, longer lifetime, improved time response and rapid species change. Great care was taken in the design of the vacuum system to provide appropriately low pressures at critical points ensuring high beam purity and high dosimetry accuracy.
Properties of the histones associated with simian virus 40 replicative form nucleoprotein complex.

Abstract Nucleoprotein complexes containing replicative form SV40 DNA were isolated from infected cells. Electrophoretic analysis of purified samples in 15% acrylamide gels revealed the presence of histones H1, H3, H2B, H2A and H4. In addition, the complex electrophoretic patterns of these histones contained a series of protein bands migrating in the expected positions for acetylated subfractions of histones H3 and H4. The identity of these bands was supported by their relatively high specific activities when [ 14 C]acetate was incorporated.
Fluid flow in subducting slabs

When subducting oceanic plates descend into the Earth's mantle, they bring a significant amount of water with them that is subsequently released at depths.Faccenda et al. used a thermomechanical model of a subducting dehydrating oceanic plate to study fluid flow in the dehydrating slab. They show that as a slab bends and unbends as it descends, stresses drive fluids toward a layer of lower pressure in the center of the plate. Together with the dehydrating oceanic crust, this fluid-rich layer forms a double hydrated zone, which the authors believe corresponds to 20- to 30-kilometer-thick regions called double seismic zones that have been observed in seismological studies.
Comparison of three optical coherence tomography scanning areas for detection of glaucomatous damage.

Purpose Several cross-sectional studies have demonstrated the capability of optical coherence tomography (OCT) to detect glaucomatous changes. OCT enables posterior pole scanning of three regions: macula, peripapillary, and optic nerve head (ONH). This study compared the ability of each region to detect glaucomatous damage. Design Retrospective observational cross-sectional study. Methods The study included 37 normal (37 subjects) and 37 glaucomatous eyes (26 subjects) that had comprehensive ocular examination, reliable and reproducible Swedish interactive thresholding algorithm standard 24–2 perimetry, and Stratus OCT scanning of macula, peripapillary, and ONH regions on the same visit. Optical nerve head (ONH) appearance did not form part of the inclusion criteria. The main outcome measure, was area under receiver operating characteristic curves (AROCs) that was calculated for each scanning region for distinguishing between normal and glaucomatous eyes. Results The highest AROCs for distinguishing between groups were for ONH parameters (rim area = 0.97, horizontal integrated rim width = 0.96, vertical integrated rim area = 0.95) and peripapillary nerve fiber layer (NFL) thickness (0.94) followed by macular volume and thickness (both 0.80). A statistically significant difference existed in ONH and NFL AROCs when compared with macular AROCs (P ≤ .007, for both) Conclusions OCT ONH and NFL parameters provided similar discrimination capabilities between healthy eyes and those of glaucoma patients and superior discrimination capabilities when compared with macular parameters.
P120 Catenin Recruits Cadherins to γ-Secretase and Inhibits Production of Aβ Peptide

The γ-secretase complex cleaves many transmembrane proteins, including amyloid precursor protein, EphB and ErbB tyrosine kinase receptors, Notch1 receptors, and adhesion factors. Presenilin 1, the catalytic subunit of γ-secretase, associates with the cadherin/catenin cell-cell adhesion/communication system and promotes cadherin processing (Georgakopoulos, A., et al. (1999) Mol. Cell 4, 893–902; Marambaud, P., et al. (2002) EMBO J. 21, 1948–1956), but the mechanism by which γ-secretase and cadherins associate is unclear. Here we report that p120 catenin (p120ctn), a component of the cadherin-catenin complex, recruits γ-secretase to cadherins, thus stimulating their processing while inhibiting production of Aβ peptide and the amyloid precursor protein intracellular domain. This function of p120ctn depends on both p120ctn-cadherin and p120ctn-presenilin 1 binding, indicating that p120ctn is the central factor that bridges γ-secretase and cadherin-catenin complexes. Our data show that p120ctn is a unique positive regulator of the γ-secretase processing of cadherins and a negative regulator of the amyloid precursor protein processing. Furthermore, our data suggest that specific members of the γ-secretase complex may be used to recruit different substrates and that distinct PS1 sequences are required for processing of APP and cadherins.
Persistent psychological or physical symptoms following endoscopic procedures: an unrecognized post-endoscopy adverse event.

Background Depression and post-traumatic stress disorder have been described after surgical procedures, but not after gastrointestinal endoscopy. Aims The aim of our retrospective survey was to determine if new-onset, persistent (>1 month) psychological and/or physical symptoms develop after gastrointestinal endoscopy. We also sought to assess how endoscopy teams respond to patient discomfort during the procedure. Methods We conducted in-person interviews among 57 gastroenterologists and endoscopy nurses at two large academic medical centers and a community hospital. Response rate was 81% (57/70). Results Among gastroenterologists surveyed, 62% had encountered at least one patient with persistent new-onset unexplained physical symptoms, and 48% had encountered at least one patient with persistent new-onset psychological symptoms that started after an endoscopic procedure. A total of 44 such patients were identified, and most were women between 20 and 40 years of age. Common new symptoms that developed after gastrointestinal endoscopy were abdominal discomfort, diarrhea, globus sensation, anxiety disorder and depression. Duration of these symptoms was 1 month to 3 years. Gastroenterologists reported that 4% and endoscopy nurses reported that 10% of patients undergoing endoscopy gestured or requested that the endoscopic procedure be prematurely stopped due to discomfort. Only 11/29 (38%) physicians reported that while obtaining consent for endoscopic procedures, they routinely discuss the possibility of stopping prematurely if the patient becomes uncomfortable. Conclusion Persistent physical or psychological symptoms can develop in some patients after endoscopic procedures.
Distinct roles for direct and indirect pathway striatal neurons in reinforcement

Dopamine signaling is implicated in reinforcement learning, but the neural substrates targeted by dopamine are poorly understood. We bypassed dopamine signaling itself and tested how optogenetic activation of dopamine D1 or D2 receptor–expressing striatal projection neurons influenced reinforcement learning in mice. Stimulating D1 receptor–expressing neurons induced persistent reinforcement, whereas stimulating D2 receptor–expressing neurons induced transient punishment, indicating that activation of these circuits is sufficient to modify the probability of performing future actions.
Net uptake of adenine nucleotides by newborn rat liver mitochondria

Abstract In newborn rat liver, the adenine nucleotide content (ATP + ADP + AMP) of mitochondria increases severalfold within 2 to 3 h of birth. The net increase in mitochondrial adenines suggests a novel mechanism by which mitochondria are able to accumulate adenine nucleotides from the cytosol ( J. R. Aprille and G. K. Asimakis, 1980, Arch. Biochem. Biophys. 201 , 564. ). This was investigated further in vitro . Isolated newborn liver mitochondria incubated with 1 m M ATP for 10 min at 30 °C doubled their adenine nucleotide content with effects on respiratory functions similar to those observed in vivo : State 3 respiration and adenine translocase activity increased, but uncoupled respiration was unchanged. The mechanism for net uptake of adenine nucleotides was found to be specific for ATP or ADP, but not AMP. Uptake was concentration dependent and saturable. The apparent K m ′s for ATP and ADP were 0.85 ± 0.27 m M and 0.41 ± 0.20 m M , respectively, measured by net uptake of [ 14 C]ATP or [ 14 C]ADP. The specific activities of net ATP and ADP uptake averaged 0.332 ± 0.062 and 0.103 ± 0.002 nmol/min/mg protein, respectively. ADP was a competitive inhibitor of net ATP uptake. If P i was omitted from the incubations, net uptake of ATP or ADP was reduced by 51%. Either mersalyl or N -ethylmaleimide severely inhibited the accumulation of adenine nucleotides. Net ATP uptake was stoichiometrically dependent on MgCl 2 , suggesting that Mg 2+ is accumulated along with ATP (or ADP). Uptake was energy dependent as indicated by the following results: Net AdN uptake (especially ADP uptake) was stimulated by the addition of an oxidizable substrate (glutamate) and inhibited by FCCP (an uncoupler). Antimycin A had no effect on net ATP uptake but inhibited net ADP uptake, suggesting that ATP was able to serve as an energy source for its own accumulation. If carboxyatractyloside was added to inhibit the exchange translocase, thereby preventing rapid access of exogenous ATP to the matrix, net ATP uptake was inhibited; carboxyatractyloside had no effect on ADP uptake. It was concluded that the net uptake of adenine nucleotides from the extramitochondrial space occurs by a specific transport process distinct from the classic adenine nucleotide exchange translocase. The accumulation of adenine nucleotides may regulate matrix reactions which are allosterically affected by adenines or which require adenines as a substrate.
Reinstatement of precipitated narcotic withdrawal hypothermia in the rat.

Abstract Withdrawal hypothermia can be induced in rats by injection of naltrexone 72 h after subcutaneous implantation of a morphine pellet. At 45 days after implantation the same dose of naltrexone is without effect on body temperature and the animals are normally sensitive to the hypothermic effect of acute morphine administration. This acute administration of morphine re-sensitizes the animals to naltrexone so that administration of the antagonist again causes withdrawal hypothermia. These results are consistent with the view that narcotic dependence can be reinstated in previously dependent, but not naive, animals by acute administration of the narcotic.
Living Foraminifera of West Flower Garden Bank: ABSTRACT

The West Flower Garden Bank is a calcareous prominence on the outer edge of the Texas-Louisiana continental shelf, rising to within 20 m of the sea surface. An actively growing fauna of West Indian scleractinian corals caps the top 30 m of the bank, and represents the northernmost known flourishing coral reef in the Gulf of Mexico. The bank supports a foraminiferal fauna related to that present on the West Indian and Florida-Bahamian reefs. Within the sediments most species and individuals are attached to coarse sedimentary particles, rather than being free tests. The largest populations are attached to large scleractinian colonies in the upper part of the bank and to algal nodules that occur at a depth of 46-82 m. End_of_Article - Last_Page 1904------------
Non-linear strain invariant failure approach for fibre reinforced composite materials

The strain invariant failure theory (Gosse and Christensen, 2001) is a micromechanics-based failure theory that depends on computation of critical strain invariants for the fibre and matrix phases. In this paper, a novel approach is developed for including the non-linear effects of the matrix through the implementation of the J2 flow theory for the matrix response. The non-linear isotropic hardening is introduced for the analysis of a non-linear matrix in square and hexagonal fibre packaging geometries. The results are presented for a common type of structural composite made from carbon fibres and an epoxy matrix. The proposed approach is used to predict the stress and strain concentration factors in a multi-cell array and shows the necessity of including the non-linear response in the analytical approach in this theory.
Us and Them Conflict, Collaboration, and the Discursive Negotiation of Multishareholder Roles in School District Reform

This article explores the conflict that emerged during the work of university researchers, education consultants, and district multishareholder teams engaged in a partnership for school reform. The authors draw on analysis of naturally occurring talk and other data collected over 2 years to explore the presence of conflict between a multishareholder team and a group of consultants during a 4-day learning lab. Investigation shows how discursive practices produce, reproduce, and transform the group over time, ultimately leading to the collaboration necessary for implementation of the reform plan. The authors elaborate on two main discursive practices: (a) the juxtaposing and problematizing of behavior, positioning participants' group membership in relation to the speaker, and (b) the use of certain pronouns. Analysis informs educational leaders working in multishareholder teams by illustrating discursive practices that might facilitate and hinder collaboration among different shareholders.
A thirteenth century ‘proof’ of the parallel postulate

Abstract Proposition I.14 of Witelo's Perspectiva purports to provide a proof of the claim contained in Euclid's fifth postulate. The Latin text of the proposition is presented and translated into English; a commentary on the nature of the ‘proof’ is also provided.
Cooperation and Contracts

In a conflict between two people, one person wants one thing and the other wants something else and they think they can't both have what they want. Suppose that what they want can only be the outcome of some joint action. Adam must do either y or z and Eve either y ' or z ' – here y -and- y ' would be one joint action, y -and- z ' would be another, and so on. Adam wants the outcome of his doing z while Eve is doing y '. Eve wants the outcome of her doing z ' while Adam is doing y . Each thinks that these outcomes can't both be had.
Experiments in numerical methods for a problem in combustion modeling

Abstract In this paper, we have shown that the numerical method of lines can be used effectively to solve time dependent combustion models in one spatial dimension. By the numerical method of lines (NMOL), we mean the reduction of a system of partial differential equations to a system of ordinary differential equations (ODE's), followed by the solution of this ODE system with an appropriate ODE solver. We used finite differences for the spatial discretization and a variant of the GEAR package for the ODE's. We have presented various solution methods of interest for the nonlinear algebraic system in this setting; that is, in the corrector iteration section of the GEAR package applied to combustion models. These methods include Newton/block SOR (SOR denotes successive over-relaxation), block SOR/Newton, Newton/block-diagonal Jacobian, Newton/kinetics-only Jacobian, and Newton/block symmetric SOR. These methods have in common their lack of frequent use in ODE software and their eady applicability to partial differential equations in more than one spatial dimension. Finally, we have given the results of numerical tests, run on the CDC-7600 and Cray-1 computers. By so doing, we indicate the more promising nonlinear system solvers for the NMOL solution of combustion models.
Cytochrome c552 and nitrite reduction in Escherichia coli

Abstract The influence of growth conditions on the synthesis of cytochrome c552 and the activities of NADH-nitrite oxidoreductase (EC 1.6.6.4) and NADH-cytochrome c oxidoreductase (EC 1.6.99.3) have been studied in Escherichia coli strain K12. Nitrite added to anaerobic cultures stimulated cytochrome c552 synthesis as well as nitrite and cytochrome c reductase activities. These were decreased by high concentrations of glucose or amino acids, and were low or absent in aerobically grown cells. When cells were suspended in sucrose and lysozyme (EC 3.2.1.17), and EDTA added, 80% of the cytochrome c552 was released into solution. The NADH-nitrite oxidoreductase activity remaining in the osmotically sensitive spheres so formed was the same as in untreated cells. Nitrite reductase activity and cytochrome c552 were also separated by gel filtration, and by (NH4)2SO4 fractionation. When cytochrome-rich fractions were recombined with nitrite reductase active fractions, no stimulation of the rate of NADH oxidation by nitrite was observed. In every experiment cytochrome c reductase and nitrite reductase activities were found in the same fractions in approximately the same ratio. Both reductases showed substrate inhibition with respect to NADH: the pH optima were 7.9 for nitrite reductase and 8.6 for cytochrome c reductase. It is suggested that cytochrome c reductase activity is due to a lack of specificity of nitrite reductase for an electron acceptor, and that cytochrome c552 is not a physiological intermediate in either reaction. An alternative function for cytochrome c552 in nitrite reduction has been suggested.
Deviation of the Allergic IgE to an IgG Response by Gene Immunotherapy

The Th1/Th2 type immune response to E. coli β-galactosidase (β-gal) was compared to that to gene vaccination with plasmid (p) DNA encoding β-gal. BALB/c mice were immunized with β-gal in alum or a pDNA construct consisting of a CMV-based promoter and the β-gal gene (pCMV-LacZ). β-gal in alum induced IgGl and IgE antibodies and the CD4+ T cells from these mice secreted interleukin 4 (IL-4) and IL-5 but no interferon-γ (IFN-γ) after in vitro antigen stimulation. In contrast, mice immunized with pCMV-LacZ formed predominantly IgG2a antibodies and their CD4+ T cells secreted IFN-γ but no IL-4 and IL-5. These data indicate that β-gal induced a Th2 and the pCMV-LacZ a Th1 response to β-gal. The pDNA induced Th1 response dominated over the Th2 response. Mice primed with pCMV-LacZ failed to produce IgE antibodies after a booster injection of β-gal in alum. Boosting of mice primed with β-gal in alum with pCMV-LacZ resulted in a 75% decrease in the IgE antibody liter within 6 weeks and IgG2a antibody formation and ...
Hominid cranial capacity versus time: A regression approach

Abstract The application of a linear regression approach to hominid data shows that there is more regularity in hominid cranial capacity over time than has been supposed. Two outcomes of this analysis are: (1) the possibility that the South African Australopithecus africanus sites are older than the presently accepted estimates of perhaps around 2·5 million years and (2) the suggestion that the Ngandong (Solo) cranial material is also considerably older than generally assumed; probably, in excess of approximately 250,000 years B.P.
KNOWLEDGE WORKER TEAM EFFECTIVENESS: THE ROLE OF AUTONOMY, INTERDEPENDENCE, TEAM DEVELOPMENT, AND CONTEXTUAL SUPPORT VARIABLES

This study investigated how autonomy, interdependence, and team development, along with process and contextual support variables, were related to the effectiveness of teams of “knowledge workers.” The sample included 231 knowledge workers from 27 work teams. Team members completed surveys measuring the design, process, and contextual factors. Effectiveness measures included multiple key stakeholder evaluations of team performance and self-report measures of attitudinal outcomes. The results suggest that interactions among design, process, and contextual support factors have important implications for team effectiveness. In particular, the positive relationship between team autonomy and team job motivation was reduced as teams worked under more interdependent conditions. This interaction effect also varied across the types of autonomy (e.g., planning-related, product-related, and people-related) the team was given. Results also demonstrated that the relationship between job motivation and team process behaviors (helping, sharing, and innovating) was more positive in teams who were developmental mature. Process behaviors were positively related to effectiveness, but those relationships became more positive in the presence of certain contextual factors (high-quality goals and efficient information transmission), and less positive in the presence of others (feedback and time pressure). Future research needs and practical implications of these results are discussed.
Benzo- and cyclohexanomazindol analogues as potential inhibitors of the cocaine binding site at the dopamine transporter.

A series of mazindol (1), homomazindol (2), and bishomomazindol (3) derivatives with a benzo or cyclohexano ring fused at various sites were prepared as part of an SAR study to determine the effect of increased aliphatic and aromatic lipophilicity on selected in vitro assays used to identify potential cocaine-like and cocaine antagonism activity. Very good (IC50 = 2−3 nM) inhibition of [3H] WIN 35,428 and [125I] RTI-55 binding on rat or guinea pig striatal membranes and HEK cells expressing cDNA for the human dopamine transporter (HEK-hDAT) was shown by the 8,9-benzomazindol 25 and 9,10-benzohomomazindol 28. All new compounds were weaker inhibitors of [3H] DA uptake in HEK-hDAT cells than 1 and 2. No improvement in the binding selectivity ratio (SERT/DAT and NET/DAT) was found when compared to 2. Compounds 25 and 28 showed a considerable increase versus 1 in uptake/binding discrimination ratios at the DAT (311.0 and 182.1 vs 0.9), SERT (33.6 and 127.3 vs 1.9), and NET (7.3 and 10.0 vs 0.3).
Graduate Journal: Facing the reviewers

It is somewhat disheartening to reflect on my years of research and then look at the figures I've assembled for my first real research paper. I am proud of my near-finished work, but all those pages of failed experiments are hard to swallow, when I look at just seven pages of pretty pictures.
Somatic mutations and aging: a re-evaluation

Aging has been explained in terms of an accumulation of mutations in the genome of somatic cells, leading to tissue atrophy and neoplasms, as well as increased loss of function. Recent advances in transgenic mouse modeling and genomics technology have created, for the first time, the opportunity to begin testing this theory. In this paper the existing evidence for a possible role of somatic mutation accumulation in aging will be re-evaluated on the basis of the evolutionary logic of aging and recent insights in genome structure and function. New strategies for investigating the relationship between genome instability, mutation accumulation and aging will be discussed.
Fracture initiation at sharp notches: Correlation using critical stress intensities

Abstract In the context of linear elasticity, a stress singularity of the type K n r δ (δ K n . The magnitude of the intensity fully characterizes the stress state in the region of the corner. A critical value of K n may be appropriate as a failure criterion in situations where the region around the corner dominated by the singular field is large compared to intrinsic flaw sizes, inelastic zones, and process zone sizes. We determined K n for notched mode I three-point flexure specimens using a combination of the Williams (Williams, M. L. (1952) Stress singularities resulting from various boundary conditions in angular corners of plates in extension. Journal of Applied Mechanics 74, 526–528) asymptotic method, dimensional considerations, and detailed finite element analysis. We carried out an experimental study of the feasibility of using a critical value of K n to correlate failure with a series of notched polymethyl methacrylate (PMMA) three-point flexure specimens with notch angles of 60°, 90°, and 120°. Using the measured failure loads and the finite element solutions for K n , we infer the critical notch stress intensity K cr n , for sharp-notched PMMA. The data show that excellent failure correlation is obtained through the use of the single parameter K cr n , Furthermore, simple estimates of the size of the inelastic zone for the notched PMMA specimens show it to be small relative to the singularity-dominated zone. This supports the applicability of linear elastic notch mechanics (LENM), and the idea that a critical value of K n can be used to correlate fracture initiation.
Worker-owners as an Emergent Class: Effects of Cooperative Work on Job Satisfaction, Alienation and Stress:

In light of the recent proliferation of several types of cooperatives in the US and Western Europe, this paper argues that the worker-owners, or cooperators, in these organizations occupy an emergent class position which is structurally different from that of conventional workers or of the petty bourgeoisie, their two nearest class equivalents. We argue that this new class position has implications for the job satisfaction, expectations, alienation and stress associated with work. We bring together empirical findings from our own studies and from other researchers' studies of cooperatives in order to develop some original hypotheses and to provide suggestive evidence concerning the effects of worker-ownership and control on the individual worker-owners. In the end, we argue that although workplace democracy may bring more meaning and sense of community to work, certain structural features of cooperatives also give rise to high levels of personal stress.
PHOTOPRODUCTS OF BROMOURACIL‐LABELED DNA AND THE STRUCTURE OF 5‐BROMODEOXYURIDYLYL‐(3' → 5')‐THYMIDINE PHOTOPRODUCT

— –An attempt was made to identify some of the ultraviolet (u.v.) photoproducts of 5-bromouracil-labeled DNA (BrU-DNA). Two synthetic dinucleotides, 5-bromodeoxyuridylyl-(3' 5 ')-thymidine (BrdUpT) and 5-bromodeoxyuridylyl-(3' 5')-deoxycytidine (BrdUpdC), were prepared. Each gave a single u.v. photoproduct which in turn gave a single acid hydrolysis product. 2-14C-BrU-DNA. prepared from E. coli B3, was irradiated (275–280 nm), hydrolyzed, and paper chromatographed in four systems. Comparison with the two synthetic photoproducts showed that if present at all, BrdUpT and BrdUpdC photoproducts could account for no more than 10 and 3.5 per cent respectively of the total photoproducts. At 55 per cent conversion of BrU into photoproducts, the major 14C-photoproduct was uracil (78 per cent); the remaining 22 per cent was made up of at least six products, three of which were reversed by 232 nm irradiation. The debrominated cyclobutane structure proposed by Haug for BrdUpT photoproduct has been shown to be incorrect. It was found to contain one atom of bromine per molecule. On the basis of nuclear magnetic resonance and u.v. spectra, two possible structures are proposed for the photoproduct, each containing an eight-membered ring.
Failure of adjuvant immunotherapy to prevent central nervous system metastases in malignant melanoma patients

A review of our experience using BCG immunotherapy as a postsurgical adjunct in the treatment of melanoma shows that the incidence of systemic metastases appears to have been reduced. However, central nervous system (CNS) metastases continue to develop in these patients and represent the single most frequent cause of death. Serial studies of immune competence in these patients reveal that those with CNS metastases usually retain normal immune responses, whereas those with metastases at other sites exhibit progressive immunosuppression with advancing disease.
Stress relaxation and elastic decohesion of viscoelastic polymer solutions in extensional flow

Abstract The evolution of the transient extensional stresses in dilute and semi-dilute viscoelastic polymer solutions was measured with a filament stretching rheometer of a design similar to that first introduced by Sridhar et al. The solutions were polystyrene-based Boger fluids which were stretched at constant strain rates in the range 0.6 ⩽ ϵ 0 ⩽ 4 s−1 and to Hencky strains of ϵ > 4. The test fluids all strain-hardened and Trouton ratios exceeding 1000 were obtained at high strains. In addition to measuring the transient tensile stress growth, the decay of the tensile viscoelastic stress in the fluid column following cessation of uniaxial elongation was also monitored as a function of the total imposed Hencky strain and the strain rate. The measured relaxation functions were found to be significantly different from those observed following cessation of steady shear flow. The extensional stresses initially decayed very rapidly upon cessation of uniaxial elongation followed by a slower viscoelastic relaxation. For the most elastic fluids, partial decohesion of the fluid filament from the endplates of the rheometer was observed in tests conducted at high strain rates. This elastic instability is initiated near the rigid endplate fixtures of the device and it results in the progressive breakup of the fluid column into individual threads or ‘fibrils’ with a regular azimuthal spacing. These fibrils elongate and bifurcate as the fluid sample is elongated further. In tests conducted at the highest Deborah numbers, complete sample decohesion from the endplates and rapid elastic recoil were sometimes observed. The critical stress and strain at the onset of the instability were determined by monitoring the tensile force exerted by the filament, the sample radius, and were used to construct an approximate stability diagram. Flow visualization experiments using a modified stretching device showed that the instability develops as a consequence of an axisymmetry-breaking meniscus instability in the non-homogeneous region of highly deformed fluid near the rigid endplate.
Generality of the environmentally benign catecholate method to the synthesis of barium-based perovskites

Abstract Barium titanate, barium zirconate, and barium hafnate are essential components of the electroceramic industry. Barium titanate is essentially used as multi-layered ceramic capacitors in computers, aerospace, and communication technologies. Barium zirconate is one of the most inert, stable, and corrosion-resistant perovskite employed in superconducting applications. Barium hafnate is used as a component of hybrid ceramic structures for high-temperature applications. The goal of this research was to apply a more environmentally benign synthesis design to the production of barium-based perovskites. The catecholate method, originally applied to the synthesis of barium titanate, was utilized as the approach for the synthesis of barium zirconate and barium hafnate. This developmental process consumed naturally occurring isomorphic forms of metal oxides and no post-sintering treatment was necessary. It resulted in the absence of by-products in most steps while achieving superior stoichiometric control o...
Hydrodynamic analysis of calenderable PVC and ABS compounds

Calendering of rigid and semirigid PVC (and ABS) compounds require an understanding of compound rheology and critical processing parameters. Compound rheology is modified with processing aids and lubricants. The choice of processing aid can be critical to achieving the desired rheology needed for calendering. This paper will focus on defining calendering rheology parameters as a function of a super high molecular weight MMA/SAN copolymer processing aid. These rheology parameters will be defined in terms of mill roll gap pressure, adhesive force (compound roll release) melt temperature, and shear rate. The ability to measure these parameters via a computerized two roll mill and relate this data to the actual calendering line will also be discussed.
Paw-shake response and locomotion: can one CPG generate two different rhythmic behaviors?

Rhythmic limb movements like locomotion or paw-shake response are controlled by network of spinal circuits, known as central pattern generators (CPGs), as evidenced from locomotor-like and paw-shake like activity in limb peripheral nerves elicited in decerebrate or spinal animals with blocked neuromuscular transmission [4]. Unlike fictive locomotion and scratch, that are likely controlled by distinct CPGs [3], fictive paw-shake response has not been systematically investigated and it is not known whether it is controlled by a specialized CPG or by the CPG that also controls locomotion. In-vivo recordings of paw-shake motor patterns elicited by stimulation of paw skin afferents [7] have revealed high frequency hindlimb oscillations (~10 Hz) with atypical muscle synergies – reciprocal activation of anterior and posterior hindlimb muscles in each half of the paw-shake cycle; both anterior and posterior muscle groups include flexor and extensor muscles. We asked whether a paw-shake response with the atypical muscle synergies can be generated by a typical half-center locomotor CPG reciprocally activating flexor and extensor muscles. Using software AnimatLab [2] we developed a 5-segment cat hindlimb model with 12 Hill-type muscle actuators controlled by (1) a half-center CPG activating flexor and extensor muscles (two-joint muscles received both flexion- and extension-related signals [5,6]) and (2) proprioceptive input originated from the muscle spindle and Golgi tendon organ afferents. The CPG was modeled by two single-compartment spiking neurons in a half-center configuration. Other neurons (Ia-afferents, alpha-motor neurons, Ia-interneurons, and interneurons mediating autogenic and heterogenic reflex pathways) were modeled as non-spiking neurons (firing rate model based on work by [1]). Model parameters were adjusted such that computer simulations reproduced the recorded paw-shake mechanics and the anterior-posterior muscle activation patterns. The obtained results demonstrated that a half-center locomotor CPG can produce movement mechanics and muscle activity patterns typical for paw-shake responses if (1) the locomotor CPG is capable to operate at frequencies 3 to10 times higher than during locomotion and (2) synaptic weights in spinal circuits can be modified during paw-shake response. We speculate that the two conditions can be realized by sensory input from paw skin afferents.
Fast Quantitative Real-Time PCR-Based Screening for Common Chromosomal Aneuploidies in Mouse Embryonic Stem Cells

Chromosomal integrity has been known for many years to affect the ability of mouse embryonic stem cells (mESCs) to contribute to the germline of chimeric mice. Abnormal chromosomes are generally detected by standard cytogenetic karyotyping. However, this method is expensive, time consuming, and often omitted prior to blastocyst injection, consequently reducing the frequency of mESC-derived offspring. Here, we show a fast, accurate, and inexpensive screen for identifying the two most common aneuploidies (Trisomy 8 and loss of chromosome Y) in genetically manipulated mESCs using quantitative real-time PCR (qPCR). Screening against these two aneuploidies significantly increases the fraction of normal mESC clones. Our method is extremely sensitive and can detect as low as 10% aneuploidy among a large population of mESCs. It greatly expedites the generation of mutant mice and provides a quick tool for assessing the aneuploidy percentages of any mESC line.
Proliferation of a highly androgen-sensitive ductus deferens cell line (DDT1MF-2) is regulated by glucocorticoids and modulated by growth on collagen

Proliferation of the hamster ductus deferens cloned tumor cell line (DDT1MF-2) in monolayer culture is markedly stimulated by androgens in a dose dependent fashion. Furthermore, growth on collagen confers upon these cells a greater dependence on this class of hormones, such that testosterone (10 nM) induces a 15-fold elevation in cell number compared to controls. Addition of either dexamethasone (10 nM) or triamcinolone acetonide (TA; 10 nM) dramatically blocks this stimulation by reversibly arresting the cells in the G1 phase of the cell cycle as assessed by flow cell cytometry. Associated with the decreased growth rate is a change from a rounded to a more flattened morphology that may also implicate cell shape in the regulation of proliferation.
Mortality level, desired family size, and population increase: comment.

In this paper an attempt is made to elaborate on the behavioral assumptions underlying a simulation model published in a previous volume of this journal (Heer and Smith, 1968). The present paper contains a discussion of the ways in which a fall in the death rate of children will affect the desirability of another birth if the family's objective is to have a son surviving to the father's sixty-fifth birthday. The death rate affects both the expected costs of and benefits from an additional birth. An examination of the effects of a decline in child mortality indicates that the benefits from an additional birth fall and the expected costs rise as a result of the decline. Thus a death rate will eventually be reached where costs exceed benefits, and parents will not desire an additional pregnancy.
Length-Tension Relations in Cardiac Muscle

The distinguishing mechanical characteristics of cardiac muscle are(1) the presence of a significant and sometimes labile resting tension at functional lengths. Certain invertebrate skeletal muscles also possess this property, but the structural basis seems to be different.(2)Force-velocity characteristics of heart muscle are labile and constitute a mechanism for regulating cardiac performance.(3)Data on quick-stretch and release show that the active state in heart muscle is slow in its onset, probably preceding the development of isometric tension by only a short time.The onset of the active state is labile also, and probably forms the basis of the regulatory function of the force-velocity relation. Measurements of heat show a slow rate of increase of heat during a twitch consistent with the onset of contractility.
Optimization and Assessment of Agricultural Water-Sharing Scenarios under Multiple Socioeconomic Objectives

The allocation of irrigation water to multiple, spatially distinct sites is one of the oldest and most important problems in water resources planning and management. However, past technical investigations have focused almost exclusively on allocation for an optimization objective and have not diagnosed the tradeoffs existing between this objective and other important socioeconomic goals such as equity and security. A common optimization technique is reviewed and adapted to multiple levels of irrigation allocation. The process of spatial distribution is then investigated for five different hypothetical allocation scenarios, which represent various definitions of the objectives of efficiency, equity, and security. A semihypothetical case study for the Lake Victoria Basin in East Africa is used to illustrate international water and crop production distributional effects of the five water-sharing scenarios. It is found that pursuit of nonefficiency objectives does entail material costs. The magnitude of these...
Distinct CCN activation kinetics above the marine boundary layer along the California coast

[1] The influence of aerosols on cloud properties remains one of the largest sources of uncertainty in estimates of the anthropogenic component of climate change. Here we report the rate of cloud droplet formation on particles sampled at a site near the California coast that is typically above the marine boundary layer. We observed persistent bimodal diameter spectra which are better explained by kinetic limitations than by differences in equilibrium properties. The slowly-growing mode contained 10–25% of the total cloud condensation nuclei (CCN) and had apparent mass accommodation coefficients (α) 10–30 times smaller than that measured for ammonium sulfate. Cloud parcel modeling suggests that most of these slowly-growing CCN will not form cloud droplets. The relatively small and narrow size distribution of the low-α droplets suggest that a condensed film is a more likely cause of these limitations than slow dissolution.
Winter Activity of Ixodes scapularis (Acari: Ixodidae) and the Operation of Deer-Targeted Tick Control Devices in Maryland

Host-seeking activity of adult blacklegged ticks, Ixodes scapularis Say was monitored by flagging during winter months in Beltsville, MD. Ticks were active many days during January and February, the coldest months, with some captures made when there was 70% snow cover and temperatures as low as -2 degrees C. Substantial numbers (70-90 ticks/h of flagging) of adult I. scapularis were captured on favorable days in January and February. The cost to treat white-tailed deer, Odocoileus virginianus (Zimmermann), using '4-poster' deer self-treatment devices, was estimated on a per female tick basis. We estimated deer abundance and tick attachment rates using data from the literature, tick activity levels using weather data and drag counts of ticks, and costs to operate the devices from experience. We found that self-treatment devices need not be operated continuously from late December until the third week of February. On average, savings of half the operating costs would be realized by not operating the devices when tick activity was low.
The technical communicator as knowledge engineer

The author compares knowledge engineering with technical communication, and argues that technical communicators are well suited to assume the role of knowledge engineer. Seven activities are discussed which constitute a practical development strategy for knowledge-based systems: (1) harvesting knowledge, (2) selecting the right problem, (3) preparing the development plan, (4) selling the system, (5) selecting your tools, (6) building the prototype, and (7) incremental development and fielding the system. >
Workstation Prototypes: A Human Engineering Approach

In April 1989 a concerted effort was undertaken by the Human Factors Engineers of the IBM Federal Systems Division in Boulder, Colorado to research and design the workstation area of a mobile ground shelter. This mobile ground shelter is designed to ride and function on the trailer of a standard semi-truck. The intent was to devise a functional, human-centered design that met the specifications of tasks being performed. A series of four mockups were constructed as a way of iteratively evolving the design. This project is a good example of applied human factor principles though the evaluation of user input.
Faster and Smaller N-Gram Language Models

N-gram language models are a major resource bottleneck in machine translation. In this paper, we present several language model implementations that are both highly compact and fast to query. Our fastest implementation is as fast as the widely used SRILM while requiring only 25% of the storage. Our most compact representation can store all 4 billion n-grams and associated counts for the Google n-gram corpus in 23 bits per n-gram, the most compact lossless representation to date, and even more compact than recent lossy compression techniques. We also discuss techniques for improving query speed during decoding, including a simple but novel language model caching technique that improves the query speed of our language models (and SRILM) by up to 300%.
Low-voltage (≤ 20 kV) sheet beam with solenoidal focusing for w-band extended interaction klystron (EIK)

Low-voltage, high-perveance sheet beams are attractive for compact, high-power millimeter wave (MMW) amplifiers, because significantly higher beam current and RF power can be accommodated in the larger cross sectional area (as compared to conventional pencil beam devices). Furthermore, solenoidal focusing offers important advantages over the more popular periodic permanent magnet (PPM) focusing because of the higher field (and hence higher current density) that can be achieved with existing permanent magnets and the absence of orbital stability limitations.[1,2] To demonstrate these advantages, a beam stick (gun, magnet, beam tunnel, and collector) is being fabricated to generate and transport a 19.5-kV, 3.5-A sheet electron beam (0.32 mm × 4 mm) in a uniform 8.5-kG magnetic field. This beam is designed to power a 94-GHz extended interaction klystron (EIK) at ∼10-kW peak power. Simulations using MICHELLE [3] show that this beam can be transported with substantially no wall interception through a 0.4-mm-high beam tunnel over distances of 4–5 cm, approximately 4 times the length of the EIK interaction circuit.[4] A fundamental requirement for achieving this stable transport in a uniform magnetic field is avoidance of E×B drift effects (e.g., diocotron instability and beam tilting). We have suppressed these effects by utilizing an essentially planar magnetic field topology and by injecting a very uniform beam into the magnetic field in such a way that the electron guiding centers lie along the midplane and the beam edge is approximately matched to a self-electric-field potential contour in the beam tunnel. Key features of the beam stick and our design methodology will be described.
Mechanical cell lysis results of a sample preparation module for functional genomics

Mechanical cell lysis is demonstrated within a microfabricated sample preparation module that would assist functional genomics and point-of-care diagnostics. The sample preparation module is proposed as a component of a vertically integrated system with RT-PCR and capillary gel electrophoresis modules. Cell lysis is conducted within the module using a micro-barbed mechanical filter within microfluidic channels. Cell behavior within the lysis filter is qualitatively described. The filter is microfabricated using a modified DRIE process that enhances the scalloping effect to create sub-micrometer scale barbs. An integrated mRNA affinity chamber is also developed with ssDNA immobilized on a silicon surface using a self-assembled monolayer linker.