cssi/SciSciGPT-SciSciNet huggingface dataset:
An experimental study of supersonic microjets

Miniature axisymmetric supersonic nozzles were produced with exit Mach numbers ranging from 1.0 to 2.8 by forming Pyrex® capillary tubing of 0.6 and 1.2 mm inside diameter into converging-diverging channels. The nozzle contours were measured and were found to compare favorably to ideal solutions given by the axisymmetric method of characteristics. In addition, the surfaces of these nozzles were quite smooth, providing featureless flows at perfect expansion. Schlieren visualization and pitot pressure measurements of the resulting microjets were compared to the literature available for jets produced by larger-scale nozzles. A postponed transition to turbulence is noted in these microjets due to their low Reynolds number. The pitot pressure on centerline is nearly uniform at perfect expansion over core lengths up to 12 nozzle exit diameters. Supersonic microjet nozzles thus provide a more effective small-scale high-pressure gas delivery device than do sonic nozzles of comparable scale at equivalent mass flow rates. Supersonic microjets may therefore have several industrial applications.
Determinant formulas for multidimensional hypergeometric period matrices

In this article we derive closed-form determinant formulas for certain period matrices whose entries are multidimensional integrals of hypergeometric type with integrands based on power functions. Our results are motivated by the work of Varchenko [Izv. Akad. Nauk SSSR Ser. Mat. 53 (1989) 1206-1235; Izv. Akad. Nauk SSSR Ser. Mat. 54 (1990) 146-158] and Richards and Zheng [Adv. Appl. Math. 28 (2002) 602-633] who derived closed-form expressions for determinants of matrices with entries as multidimensional integrals of rational functions.
Validating an analytical technique for calculating detection probability given time-dependent search parameters

The search problem discussed in this paper is easily stated: given search parameters (Ρ ∞ , τ) that are known functions of time, calculate how the probability of a single observer to acquire a target grows with time. This problem was solved analytically in a previous paper. To investigate the validity of the solution, videos generated using NVIG software show the view from a vehicle traveling at two different speeds along a flat, straight road. Small, medium and large sized equilateral triangles with the same gray level as the road but without texture were placed at random positions on a textured road and military observers were tasked to find the targets. Analysis of this video in perception experiments yields experimental probability of detection as a function of time. Static perception tests enabled Ρ ∞ and τ to be measured as a function of range for the small, medium and large triangles. Since range is a known function of time, Ρ ∞ and τ were known as functions of time. This enabled the calculation of modeled detection probabilities which were then compared with measured detection probabilities.
Tremorgenic indole alkaloids. Studies directed toward the assembly of the A, F, and I rings of penitrem D: observation of an unexpected stereochemical outcome.

In this Letter we demonstrate the viability of a highly stereoselective tandem Mannich cyclization−grammine fragmentation/addition cascade, critical for assembly of the A and F rings of penitrem D. We also explored simultaneous execution of this tactic with concurrent construction of ring I. Reinvestigation of a model system provided an explanation for the unanticipated stereochemical outcome at C(28).
Meshfree isoparametric finite point interpolation method (IFPIM) with weak and strong forms for evaporative laser drilling

Abstract An isoparametric finite point interpolation method (IFPIM) with weak and strong forms has been developed to analyze evaporative laser drilling. The method is based on isoparametric finite point representation of the unknowns in the influence domain. The local influence domains are mapped onto a master domain where the shape functions and their derivatives are known. The solution in the master domain is approximated by a linear combination of shape functions. The present method employs a simple strong form in the domain and a weak form on the boundary. Three different types of boundary conditions considered are of essential, convection, and laser irradiation type. The problem is geometrically nonlinear because the domain is not known a priori due to material removal in drilling. An iterative scheme is used to solve the nonlinear problem. The material removal is handled by redistributing points in the domain. This renders the point distribution non-uniform as in random distribution. The numerical results show excellent agreement with those by FEM and BEM in terms of groove shape, temperature and heat flux distributions, and amount of material removal. The results are superior to those from the isoparametric finite point interpolation methods with only strong forms.
Emergency department analgesia for fracture pain

Abstract Study objectives: We analyze records of all emergency department (ED) patients with extremity or clavicular fractures to describe analgesic use, compare analgesia between adults and children, and compare analgesia between the subset of these adults and children with documented moderate or severe pain. Among children, we compare treatment between pediatric and nonpediatric facilities. Methods: Analysis of the ED component of the National Center for Health Statistics National Hospital Ambulatory Medical Care Survey for 1997 through 2000 was conducted. The proportion of patients with closed extremity and clavicular fracture that received any analgesic and narcotic analgesic medications was determined for each age category. Survey-adjusted regression analyses compared pain and narcotic medications by age and ED type (pediatric versus other). Analyses were repeated for the subset of patients with moderate or severe pain severity scores. Results: Of 2,828 patients with isolated closed fractures of the extremities or clavicle, 64% received any analgesic and 42% received a narcotic analgesic. Pain severity scores were recorded for 59% of visits overall, 47% of children younger than 4 years, and 34% of children younger than 1 year. Among patients with documented moderate or severe pain, 73% received an analgesic and 54% received a narcotic analgesic. Compared with adults, a lower proportion of children (≤15 years) received either any analgesic or a narcotic analgesic ( P Conclusion: In pediatric and adult patients, pain medications were frequently not part of ED treatment for fractures, even for visits with documented moderate or severe pain. Pain severity scores were often not recorded. Pediatric patients were least likely to receive analgesics, especially narcotics. [ Ann Emerg Med. 2003;42:197-205.]
The French Peasant and Communism

The French Communist Party emerged from the national elections of 1951 with a greater number of popular votes than any of its competitors. Since the preceding elections of November, 1946, it is true, the party has lost close to 500,000 voters, and its proportion of the total number of registered voters has declined from 21.6 to 20.1 per cent. Yet the Communist Party (CP) remains not only numerically, but also by virtue of its geographical distribution, the most important of the French parties. In none of the election districts did less than 5 per cent of the voters cast their ballot for the communist lists, while all other parties parade a considerable number of blank spots on the electoral map of France. In twenty-seven districts the CP can boast of a support larger than one-fourth of the total electorate, while the next strongest party, de Gaulle's RPF, is similarly represented in only eleven districts.A comparison of the present communist vote with that of 1946 shows that five years which affected deeply the political constellation of Europe and the world have not changed significantly the distribution of communist sympathies among the French electorate. The greatest concentration of votes for the CP is still to be found in the region situated between Paris and the Belgian border, reaching in the East to the departements of Ardennes, Marne, and Aube, in the West to those of Somme and Seine-Inferieure.
Continuous-Time Distributed Observers With Discrete Communication

This work presents a distributed algorithm for observer design for linear continuous-time systems. We assume the dynamical system to be partitioned into disjoint areas, and we let each area be equipped with a control center. Each control center knows local dynamics, collects local observations, performs local computation, and communicates with neighboring control centers at discrete times. For our continuous-discrete estimation algorithm we prove convergence, we characterize its convergence rate, and we show robustness against discretization and communication errors. Our technical approach is inspired by waveform relaxation methods and combines tools from estimation theory, decentralized control theory, and parallel computation. We illustrate the effectiveness of our algorithm with illustrative examples in sensor networks and electric power systems.
Topography of phosphatidylcholine, phosphatidylethanolamine and triacylglycerol biosynthetic enzymes in rat liver microsomes

Abstract The topography of phosphatidylcholine, phosphatidylethanolamine and triacylglycerol biosynthetic enzymes within the transverse plane of rat liver microsomes was investigated using two impermeant inhibitors, mercury-dextran and dextran-maleimide. Between 70 and 98% of the activities of fatty acid : CoA ligase (EC 6.2.1.3), sn- glycerol -3- phosphate acyltransferase (EC 2.3.1.15), phosphatidic acid phosphatase (EC 3.1.3.4), diacylglycerol acyltransferase (EC 2.3.1.20), diacylglycerol cholinephosphotransferase (EC 2.7.8.2) and diacylglycerol ethanolaminephosphotransferase (EC 2.7.8.1) were inactivated by mercury-dextran. Dextran-maleimide caused 52% inactivation of the sn- glycerol -3- phosphate acyltransferase. Inactivation of each of these activities except fatty acid : CoA ligase occurred in microsomal vesicles which remained intact as evidenced by the maintenance of highly latent mannose-6-phosphatase activity (EC 3.1.3.9). These glycerolipid biosynthetic activities were not latent, indicating that substrates have free access to the active sites. Moreover, ATP, CDP-choline and CMP appeared unable to penetrate the microsome membrane. These data indicate that the active sites of these enzymes are located on the external surface of microsomal vesicles. It is concluded that the biosynthesis of phosphatidylcholine, phosphatidylethanolamine and triacylglycerol occurs asymmetrically on the cytoplasmic surface of the endoplasmic reticulum.
Breeding and post-breeding structure of the vas deferens of the long-toed salamander Ambystoma macrodactylum.

The vas deferens of Ambystoma macrodactylum is composed of a peritoneal epithelium, connective tissue layer with fibroblasts, circular smooth muscle, capillaries, cells containing lipid, and a luminal epithelium composed of a single layer of cuboidal cells covered by a net of interconnected ciliated squamous cells. The cuboidal cells have abundant rough endoplasmic reticulum, mitochondria, and PAS + secretory vesicles. Squamous cells of breeding males consistently have tufts of ∼100 cilia located at one end of the long axis of each cell. These cilia may help distribute secretory products. The squamous cells, absent in post-breeding males, are apparently sloughed into the lumen. Lipid vesicles are present throughout the cytoplasm of the cuboidal and squamous epithelial cells and are also in some cells of the connective tissue layer. These vesicles increase dramatically in number during the first 4 weeks after breeding and may serve as an energy pool for the next breeding season. Enzyme-histochemical tests for testosterone synthesis were negative. In addition to the accumulation of lipid and the loss of squamous cells in the vas deferens, after breeding PAS + vesicle production is terminated. These alterations appear to represent energy conservation strategies employed by the sperm-depleted vas deferens.
Underwater Inspection And Surveys Using Computer Management

Mandatory underwater inspection programmes are expensive and generate large volumes of report material. Computer based systems have been developed to provide more efficient and flexible planning of these programmes, to facilitate report production and, most significantly to allow the management of the results of such inspections including trend analysis, summary reports, defect or reading ranking and so forth. This paper briefly reviews current common inspection techniques used underwater and detail how a computer aided inspection planning and reporting system was designed to satisfy the needs of underwater inspection. The basic philosophy of the system has been incorporated into six systems which have now been specifically tailored to oil companies' requirements, including one system for pipeline surveys which incorporates automatic transfer of information from the pipeline survey data processing computer system.
An Examination of Challenging Behaviors in Autistic Disorder versus Pervasive Developmental Disorder Not Otherwise Specified: Significant Differences and Gender Effects.

Abstract Children with Autism Spectrum Disorders (ASDs) are well-known for engagement in challenging behaviors. Unfortunately, due to its absence as a criterion for diagnosis in the DSM-IV-TR , little attention has been paid to the endorsement rates of such behaviors. However, a recently developed measure to assist in the diagnosis of infants and toddlers with autism and PDD-NOS – the Baby and Infant Screen for Children with aUtIsm Traits ( BISCUIT ) – has included a section designated for just this reason. This study used the BISCUIT to assess for significant differences in the endorsement rates of challenging behaviors between infants and toddlers with autism versus PDD-NOS as well as for significant differences between genders. There were significant differences between the diagnostic groups in endorsement rates of challenging behaviors as a whole, as well as among many specific behavior items. No significant differences between genders in endorsement rates of challenging behaviors were found. The implications of these findings are discussed.
Fit for purpose: engineering principles for selecting an appropriate type of data exchange standard

Data standards are a powerful, real-world tool for enterprise interoperability, yet there exists no well-grounded methodology for selecting among alternative standards approaches. We focus on a specific sub-problem within a community's data sharing challenge and identify four major standards-based approaches to that task. We present characteristics of a data sharing community that one should consider in selecting a standards approach--such as relative power, motivation level, and technical sophistication of different participants--and illustrate with real-world examples. These characteristics and other factors are then analyzed to develop decision rules for selecting among the four approaches. Independent of the data exchange problem, we suggest two general practices in choosing a standards approach: (1) vertical decomposition of interoperability issues, in order to define a narrow, formal, tractable problem, and (2) option-exclusion rules, as they are much simpler than stating optimal-choice rules.
Textural transformations in islands on free standing smectic-C* liquid crystal films.

We report on and analyze the textural transformations in islands, thicker circular domains, floating in very thin free standing chiral Smectic-${C}^{*}$ liquid crystal films. As an island is growing, an initial pure bend texture of the $c$ director changes into a reversing spiral at a critical size. Another distinct spiral texture is induced by changing the boundary condition at the central point defect in the island. To understand these transformations from a pure bend island, a linear stability analysis of the $c$-director free energy is developed, which predicts a state diagram for the island. Our observations are consistent with the theoretical phase diagram.
A patient with Huntington's disease and long-surviving fetal neural transplants that developed mass lesions.

Transplantation of human fetal neural tissue into adult neostriatum is an experimental therapy for Huntington’s disease (HD). Here we describe a patient with HD who received ten intrastriatal human fetal neural transplants and, at one site, an autologous sural nerve co-graft. Although initially clinically stable, she developed worsening asymmetric upper motor neuron symptoms in addition to progression of HD, and ultimately died 121 months post transplantation. Eight neural transplants, up to 2.9 cm, and three ependymal cysts, up to 2.0 cm, were identified. The autologous sural nerve co-graft was found adjacent to the largest mass lesion, which, along with the ependymal cyst, exhibited pronounced mass effect on the internal capsules bilaterally. Grafts were composed of neurons and glia embedded in disorganized neuropil; robust Y chromosome labeling was present in a subset of grafts and cysts. The graft–host border was discrete, and there was no evidence of graft rejection or HD pathologic changes within donor neurons. This report, for the first time, highlights the potential for graft overgrowth in a patient receiving fetal neural transplantation.
Quantifying spread F by digital ionosondes

The width of frequency-spreading (Δff) on ionograms was shown (Wright, et al., 1977, by comparison with OGO-6 Satellite observations) to be proportional to ΔNN near and above the F-region peak. Thus, even classical analog ionograms using logarithmic frequency scales were direct reading for this important parameter, although little use has been made of this fact. How can modern digital ionosondes produce (by automated methods) a comparable parameter? This paper provides an answer to the question, as the first of a series of steps aimed at exploiting the full capability of HF sounding to understand the distinctive phenomenon of Spread F.
The Bifurcation Behavior of Tubular Reactors.

Abstract Methods for studying the bifurcation behavior of tubular reactors have been developed. This involves the application of static and Hopf bifurcation theory for PDE's and the very precise determination of steady state profiles. Practical computational methods for carrying out this analysis are discussed in some detail. For the special case of a first order, irreversible reaction in a tubular reactor with axial dispersion, the bifurcation behavior is classified and summarized in parameter space plots. In particular the influence of the Lewis and Peclet numbers is investigated. It is shown that oscillations due to interaction of dispersion and reaction effects should not exist in fixed bed reactors and moreover, should only occur in very short “empty” tubular reactors. The parameter study not only brings together previously published examples of multiple and periodic solutions but also reveals a hitherto undiscovered wealth of bifurcation structures. Sixteen of these structures, which come about by combinations of as many as four bifurcations to multiple steady states and four bifurcations to periodic solutions, are illustrated with numerical examples. Although the analysis is based on the pseudohomogeneous axial dispersion model, it can readily be applied to other reaction diffusion equations such as the general two phase models for fixed bed reactors.
Nulear Extracts of Crithidia fasciculata Contain a Factor(s) That Binds to the 5′-Untranslated Regions of TOP2 and RPA1 mRNAs Containing Sequences Required for Their Cell Cycle Regulation

The Crithidia fasciculata replication protein A gene, RPA1, and topoisomerase II gene,TOP2, encode proteins involved in the replication of nuclear and mitochondrial DNA, respectively. Transcripts of both genes accumulate periodically during the cell cycle and attain their maximum levels just before S phase. Octamer consensus sequences within the 5′-untranslated region (UTR) of both genes have been shown to be necessary for cycling of these transcripts. Using a gel retardation assay, we show here that nuclear extracts of C. fasciculatacontain a protein factor(s) that binds specifically to RNA from 5′-UTRs of TOP2 and RPA1 genes. In addition, mutations in the consensus octamer sequence abolish binding to the RNA in both cases. Ultraviolet cross-linking using a radiolabeled TOP25′-UTR probe identified proteins with apparent molecular masses of 74 and 37 kDa in the RNA-protein complex. Nuclear extracts prepared from synchronized cells show that the binding activity varies during the cell cycle in parallel with TOP2 and RPA1mRNA levels. These results suggest that the cell cycle regulation of the mRNA levels of trypanosomatid DNA replication genes may be mediated by binding of specific proteins to conserved sequences in the 5′-UTR of their transcripts.
A distal regulatory region of the insulin-like growth factor binding protein-2 (IGFBP-2) gene interacts with the basic helix-loop-helix transcription factor, AP-4

Insulin-like growth factor binding protein-2 (IGFBP-2), the predominant IGFBP in the fetal circulation and an induced protein during several types of malignancies, belongs to a family of structurally related proteins that bind the mitogens, IGF-1 and IGF-2. The present study focused on functional analysis of the 5′-flanking region (∼1.3 kb) of the IGFBP-2 gene to identity nuclear factors that mediate hepatic transcription of this gene. Luciferase (LUC) reporter constructs containing progressive deletions of 5′-flanking DNA and the intact promoter of the porcine IGFBP-2 gene were examined for functional activity by transient transfection of human HepG2 liver cells. LUC activity of the transfected reporter gene driven by the IGFBP-2 promoter and flanking sequences to −1397 (numbering relative to initiation codon at +1) was 22-fold higher than that of promoterless parent LUC vector. This activity was decreased by 60% with deletion of sequences to −874 bp, and dropped to basal levels with further truncation to −764 bp. The region between −874 and −765 bp (110 bp) functioned as a potent stimulator of heterologous SV40 promoter activity (110 bp/SV40-LUC construct) and was found to contain two noncontiguous basic helix-loop-helix (bHLH) transcription factor binding motifs (E-boxes [CANNTG]: CACCTG and CAAATG). In electrophoretic mobility shift assays, nuclear proteins prepared from HepG2 cells formed two complexes (C1, C2) with double-stranded oligonucleotides containing either HLH sequence, mutations of which resulted in loss of complex formation. Southwestern blot analysis identified an HepG2 nuclear protein with molecular mass of 48 kDa, similar to that of the bHLH transcription factor AP-4, which bound the CACCTG motif. Cotransfection of HepG2 cells with the 110-bp/SV40-LUC construct and an expression vector encoding human AP-4 increased IGFBP-2 fragment-dependent SV40 promoter activity by 16-fold. This AP-4-mediated stimulation was lost following block mutation of both bHLH motifs within the IGFBP-2 110-bp fragment. Results demonstrate the functional importance of sequences upstream of the promoter in IGFBP-2 gene transcription and identify a novel mechanism by which bHLH proteins potentially may affect cell proliferation and differentiation via induction of IGFBP-2 synthesis.
CONTROL OF CAPITAL ISSUES IN THE UNITED KINGDOM

IN RECENT YEARS a growing number of economists have centered their interest on the problems inherent in secular acceleration, i.e., a long-run tendency for planned investment to exceed planned savings, rather than on the main concern of the 1930's-secular stagnation. Since the crux of this modern problem lies in methods of dealing with constant inflation, it should be useful to study what other nations are doing to meet this threat. There are many possible choices of policy in fighting inflation. If, however, it be granted for political reasons, if for no other, that full employment is to be maintained, it may become more obvious that at least one approach to the solution of the problem may lie in a limitation on net investment. One way of doing this is to regulate not only the quantity but also the type of investment seeking capital funds on the new-issues market. To some extent this line of attack has been taken by the government of the United Kingdom since 1939.
Targeted question answering on smartphones utilizing app based user classification

State-of-the-art question answering systems are pretty successful on well-formed factual questions, however they fail on the non-factual ones. In order to investigate effective algorithms for answering non-factual questions, we deployed a crowdsourced multiple choice question answering system for playing “Who wants to be a millionaire?” game. To build a crowdsourced super-player for “Who wants to be a millionaire?”, we propose an app based user classification approach. We identify the target user groups for a multiple choice question based on the apps installed on their smartphones. Our final algorithm improves the answering accuracy by 10% on overall, and by 35% on harder questions compared to the majority voting. Our results pave the way to build highly accurate crowdsourced question answering systems.
Team Performance Prediction in Massively Multiplayer Online Role-Playing Games (MMORPGs)

In this study, we propose a comprehensive performance management tool for measuring and reporting operational activities of game players. This study uses performance data of game players in EverQuest II, a popular MMORPG developed by Sony Online Entertainment, to build performance prediction models for game players. The prediction models provide a projection of player’s future performance based on his past performance, which is expected to be a useful addition to existing player performance monitoring tools. First, we show that variations of PECOTA [2] and MARCEL [3], two most popular baseball home run prediction methods, can be used for game player performance prediction. Second, we evaluate the effects of varying lengths of past performance and show that past performance can be a good predictor of future performance up to a certain degree. Third, we show that game players do not regress towards the mean and that prediction models built on buckets using discretization based on binning and histograms lead to higher prediction coverage.
Distinguishing the roles of the two different cGMP-binding sites for modulating phosphorylation of exogenous substrate (heterophosphorylation) and autophosphorylation of cGMP-dependent protein kinase.

The role of each of the two different cGMP-binding sites (referred to as slow and fast sites) of type I cGMP-dependent protein kinase (PKG) in altering the rate of catalysis of phosphorylation of exogenous substrates (heterophosphorylation) or the rate of autophosphorylation has not been resolved. In the present study, the cGMP concentration required for half-maximal activation (A50) of wild-type PKG type Iβ (WT) was 5-fold higher for heterophosphorylation than for autophosphorylation. cGMP occupation of the slow site was associated with an increase in the autophosphorylation rate, whereas occupation of the fast and slow site together was associated with a decrease in the autophosphorylation rate compared with the rate observed with occupation of the slow site alone. The contributions of each cGMP-binding site were investigated using PKG mutants containing substitutions of an invariant threonine residue that is critical for high affinity cGMP-binding in each site. Site-directed mutagenesis of Thr-317 of the fast site (T317A) increased the cGMP A50 for heterophosphorylation 4-fold at 30 °C, with nominal effect on cGMP A50 for autophosphorylation compared with WT. The analogous slow site mutation (T193A) increased the cGMP A50 for heterophosphorylation and autophosphorylation 32- and 64-fold, respectively. Compared with WT, the cGMP A50 of the double mutant (T193A/T317A) for heterophosphorylation was increased 300-fold, whereas the cGMP A50 for autophosphorylation was similar to that of T193A. Thus, occupation of both cGMP-binding sites of PKG is required for maximal stimulation of heterophosphorylation, whereas occupation of the slow site alone is sufficient for stimulation of the rate of autophosphorylation, and additional occupation of the fast site reduces this rate.
Selection and evolution of high- affinity human anti-viral antibodies

High-affinity human anti-viral antibodies [e.g. for human immunodeficiency virus type 1 (HIV-1), respiratory syncytial virus (RSV) and herpes simplex virus (HSV)] can be selected from immune phage-display libraries using a variety of strategies. A small subset of these antibodies show potent neutralization in vitro and anti-viral efficacy in vivo in animal models. The affinities of such antibodies arising from secondary or higher order immune responses can be improved using "CDR walking'. Sequential and parallel optimization variants of this strategy have been used to improve the affinity of a prototype anti-HIV-1 antibody 420-fold. Ultra-high-affinity human antibodies could constitute a new class of useful anti-viral reagents.
Analysis of the Molecular Basis of Synovial Rheumatoid Factors in Rheumatoid Arthritis

Abstract The objective of this study was to better understand the molecular basis of IgM rheumatoid factor in rheumatoid arthritis (RA). We recently generated 10 different monoclonal IgM RF (mRF) molecules isolated from the synovium of a single patient with RA. The heavy (H) and light chain (L) variable region (V) genes of these 10 mRFs were cloned and sequenced. Six mRFs used kappa light chains and 4 mRFs used lambda light chains. Of particular interest, 8 of 10 heavy chains used the JH4 joining region gene, and all five VH4 heavy chains used the DK4 diversity region gene with the JH4. Four of the VH4 clones used the same germline gene, likely representing a novel but closely related germline gene to VH4.18, and may be clonally related because of the extensive homology in their heavy chain sequence. Two VH4 clones shared the same light chain gene, VκIIIb kv325 (99% homology) and the same JK4 joining region gene, while three VH4 clones used two different light chain genes, an uncommon Vκ4 and a Vλ4 gene, respectively. In this RA patient, there was recurrent utilization of VH4-DK4-21/10-JH4 genes and a recurring association with gene elements Vκ3 and Vλ4. Recurring usage of Vκ3 (kv325) and Vλ4 (lv418) gene elements may result from a light chain editing process whereby immature autoreactive B cells encountering self-antigen attempt, and often succeed, in altering their specificities through secondary Ig light chain gene rearrangement. Moreover, the oligoclonality of these RFs suggest clonal relatedness secondary to an antigen-driven response.
Ubiquitination and degradation of the thrombopoietin receptor c-Mpl.

Regulation of growth factor and cytokine signaling is essential for maintaining physiologic numbers of circulating hematopoietic cells. Thrombopoietin (Tpo), acting through its receptor c-Mpl, is required for hematopoietic stem cell maintenance and megakaryopoiesis. Therefore, the negative regulation of Tpo signaling is critical in many aspects of hematopoiesis. In this study, we determine the mechanisms of c-Mpl degradation in the negative regulation of Tpo signaling. We found that, after Tpo stimulation, c-Mpl is degraded by both the lysosomal and proteasomal pathways and c-Mpl is rapidly ubiquitinated. Using site-directed mutagenesis, we were able to determine that c-Mpl is ubiquitinated on both of its intracellular lysine (K) residues (K553 and K573). By mutating these residues to arginine, ubiquitination and degradation were significantly reduced and caused hyperproliferation in cell lines expressing these mutated receptors. Using short interfering RNA and dominant negative overexpression, we also found that c-Cbl, which is activated by Tpo, acts as an E3 ubiquitin ligase in the ubiquitination of c-Mpl. Our findings identify a previously unknown negative regulatory pathway for Tpo signaling that may significantly impact our understanding of the mechanisms affecting the growth and differentiation of hematopoietic stem cells and megakaryocytes.
Long-Term Thermal Cycling of Phlogopite Mica-Based Compressive Seals for Solid Oxide Fuel Cells

Abstract Planar solid oxide fuel cells (SOFCs) require sealants to function properly in harsh environments at elevated temperatures. The SOFC stacks are expected to experience multiple thermal cycles (perhaps thousands of cycles for some applications) during their lifetime service in stationary or transportation applications. As a result, thermal cycle stability is considered a top priority for SOFC sealant development. In previous work, we have developed a hybrid mica-based compressive seal with very low leak rates of 2–4 × 10 −2 to 10 −3 sccm cm −1 at 800 °C, and showed stable leak rates over limited thermal cycles. In this paper we present results of long-term thermal cycle testing (>1000 thermal cycles) of Phlogopite mica-based compressive seals. Open-circuit voltage (OCV) was measured on a 2 in. × 2 in. 8-YSZ plate with the hybrid Phlogopite mica seals during thermal cycling in a dual environment (2.75% H 2 /Ar versus air). During two long-term cycling tests, the measured OCVs were found to be consistent with the calculated Nernst voltages. The hybrid mica seal showed excellent thermal cycle stability over 1000 thermal cycles and can be considered a strong candidate for SOFC applications.
CERES FM-5 on the NPP spacecraft: continuing the Earth radiation budget climate data record

The Clouds and the Earth's Radiant Energy System (CERES) Flight Model-5 (FM-5) instrument will fly on the NPOESS Preparatory Project (NPP) spacecraft, which has a launch-readiness date in June, 2010. This mission will continue the critical Earth Radiation Budget Climate Data Record (CDR) begun by the Earth Radiation Budget Experiment (ERBE) instruments in the mid 1980 s and continued by the CERES instruments currently flying on the EOS Terra and Aqua spacecraft. Ground calibrations have been completed for FM-5 and the instrument has been delivered for integration to the spacecraft Rigorous pre-launch ground calibration is performed on each CERES unit to achieve an accuracy goal of 1% for SW flux and 0.5% for outgoing LW flux. Any ground to flight or in-flight changes in radiometer response is monitored using a protocol employing both onboard and vicarious calibration sources and experiments. Recent studies of FM-1 through FM-4 data have shown that the SW response of space based broadband radiometers can change dramatically due to optical contamination. With these changes having most impact on optical response to blue-to UV radiance, where tungsten lamps are largely devoid of output, such changes are hard to monitor accurately using existing on-board sources. This paper outlines the lessons learned on the existing CERES sensors from 30+ years of flight experience and presents a radiometric protocol to be implemented on the FM-5 instrument to ensure that its performance exceeds the stated calibration and stability goals.
Fabrication of short and thin silicon cantilevers for AFM with SOI wafers

Thin and short cantilevers possess both a low force constant and a high resonance frequency, thus are highly desirable for atomic force microscope (AFM) imaging and force measurement. In this work, small silicon (Si) cantilevers integrating with a Si tip were fabricated from silicon-on-oxide (SOI) wafers that were used for reducing the variation of thickness of the cantilevers. Our fabrication process provided SOI chips containing 40 silicon cantilevers integrating with an ultra-sharp Si tip. We showed that the resolution of images obtained with these tips was much higher than those obtained with the commercial tips, while the force constants were much less, that is, more suitable for imaging soft samples. The availability of such SOI chips greatly facilitates large scale modification of the surfaces of the silicon cantilever tips with a monolayer of oligo(ethylene glycol) derivatives that resist the non-specific interactions with proteins, rendering them most suitable for imaging and measurement of biological samples.
Model calculations of the rising motion of a prominence loop

Model calculations are presented for the rising motion of the top section of a prominence loop, which is represented by a straight flux rope immersed in a coronal medium permeated with a bipolar magnetic field. Initially the prominence is at rest, in equilibrium with the surrounding coronal medium. When the magnetic monopoles that account for the source current for the bipolar field strengthen, the upward hydromagnetic buoyancy force overcomes the downward gravitational force so that the prominence is initiated into rising motion. The illustrative examples show that prominences can move away from the solar surface by the action of the hydromagnetic buoyancy force, which is preponderant with the diamagnetic force due to the current carried by the prominence interacting with the coronal magnetic field produced by the photospheric currents, if the changes in the photospheric magnetic field are sufficiently large.
Risk stratification of patients in an emergency department chest pain unit: prognostic value of exercise treadmill testing using the Duke score.

Exercise treadmill testing (ETT) has been standard for evaluating outpatients at risk for cardiovascular events. Few studies have demonstrated its prognostic usefulness in emergency department chest pain units or have used the Duke score [(exercise duration in minutes) − (5 × ST-segment deviation in millimeters) − (4 × treadmill angina index)] to grade its performance. Our objective was to assess the usefulness of this score in a chest pain unit to predict cardiovascular events. From November 2000 to October 2001, we retrospectively studied consecutive patients in the chest pain unit. Those undergoing ETT were stratified into “low” (Duke score ≥ 5) and “moderate/high” risk groups ( 24 h after presentation, revascularization, acute congestive heart failure, stroke or arrhythmia were identified within 1 year after presentation. Differences in risk of having a cardiovascular event among low-risk and moderate/high-risk groups are presented. During the study period, 1,048 patients entered the chest pain unit; 800 met inclusion criteria. Of these, 599 received ETT and 201 had contraindications or a positive finding in the chest pain unit protocol before ETT. Cardiovascular event rates were 0.7% (3/454), 15.2% (22/145) and 14.9% (30/201) after 1 month of follow-up for low-risk, moderate/high-risk and no-ETT groups, respectively. According to the Duke score, the low-risk group developed minimal cardiovascular events compared with the moderate/high-risk group. The Duke score appears effective for risk stratification of chest pain patients in chest pain units.
Comparison of microscopic epididymal sperm aspiration and intracytoplasmic sperm injection/in-vitro fertilization with repeat microscopic reconstruction following vasectomy: is second attempt vas reversal worth the effort?

Since 1986, we have performed microscopic reconstruction in 18 men following failed microscopic vasectomy reversal. Between 1994 and 1996, nine couples have undergone microscopic epididymal sperm aspiration (MESA)/ intracytoplasmic sperm injection (ICSI) treatment for male infertility due either to congenital absence of the vas deferens (CAVD) or inoperable excurrent duct obstruction. We compared the cost efficiency of repeat vasectomy reversal to that for MESA combined with ICSI/in-vitro fertilization (ICSI/IVF). The cost of male partner procedures (vasectomy reversal, MESA) was based on physician and hospital charges, while the cost of ICSI/IVF included preparation of the female partner (medications and physician charges) and procedures (physician and hospital charges including oocyte retrieval, micromanipulation, and embryo transfer). Our cost examination does not include charges related to follow-up visits, prenatal monitoring, complications of pregnancy (i.e. miscarriage) or delivery in either group. Overall patency and pregnancy rates in the repeat vasectomy reversal group were 78 and 44% respectively. The cost per delivered baby (including multiple metachronos deliveries per couple) was $14892. Fertilization of oocytes has been achieved in 37/72 (51%) and pregnancies have occurred in 6/9 (67%) attempts and 5/9 (56%) report delivery. The average cost per pregnancy was $25637 and the average cost per delivered baby (or ongoing pregnancy) was $35570. The cost per delivery by MESA/ ICSI/IVF is 2.4 times the charges per delivery obtained through repeat vasectomy repair. Couples attempting to overcome infertility caused by vasal obstruction should be informed that vas reconstruction remains a cost effective means of re-establishing fertility even in men who have previously failed vasectomy reversal.
Cholesterol lowering. Should it continue to be the last thing we do

Some of the treatments we use in cardiology must be applied urgently, such as cardiopulmonary resuscitation or thrombolytic therapy for myocardial infarction. The urgency is driven by pathophysiological imperatives, such as the need to prevent cerebral anoxia or to limit the extent of myocardial necrosis. Most other therapies can be instituted in a more leisurely way. Cholesterol lowering is often the last thing that we do, the treatment that we are slowest to initiate. One of the reasons is that cholesterol levels are depressed for several weeks after the onset of an acute coronary event,1 and some of us wait to obtain measurements. Some of us withhold drug therapy in coronary patients to see whether diet alone will be effective, even though most coronary patients will not meet the LDL cholesterol goal of 100 mg/dL with diet alone.2 Also, we have understood that cholesterol lowering appears to reduce coronary events only after a delay. The outcome curves of the secondary prevention trials do not separate appreciably until 1 to 2 years after initiation of treatment. Several pieces of accumulating evidence, including the article by Dupuis et al3 in this issue of Circulation , indicate that we may have to reassess our approach. These investigators have demonstrated in patients with unstable angina that cholesterol lowering with pravastatin improved endothelial function within 6 weeks. If cholesterol lowering has relatively immediate consequences that may favorably affect coronary events, the benefits of cholesterol lowering could be extended to acute coronary conditions, and the speed with which we initiate this form of treatment would have to increase dramatically. Unstable angina and myocardial infarction are caused by abrupt progression of coronary disease, usually due to thrombus formation on a ruptured or eroded plaque. Plaque ruptures occur frequently among patients with coronary disease.4 …
Nutrient cycling and the biogeochemistry of manganese, iron. and zinc in Jellyfish Lake, Palau

The oxic waters in Jellyfish Lake, a stagnant marine lake in Palau, are depleted in N03-, POd3-, dissolved Si, Mn, Fe, and Zn, while the underlying anoxic waters are significantly enriched in these species and NH,. NH, and Pod3 regeneration and dissolved sulfide production in the anoxic zone yield a stoichiometry of C,,,N,,P for organic matter undergoing recycling in the anoxic waters. In the anoxic zone, dissolved Mn, Fe, and Zn reach maximum concentrations of 30, 22, and 2.5 nM. The Fe concentrations are consistent with mackinawite or greigite solubility control. Mn approaches saturation with respect to haurite. Zn may be controlled by the solubility of ZnS coprecipitate. The sediments are enriched in Fe and depleted in Zn relative to Asian dust at Enewetak. A twobox model is used to calculate an eddy diffusion coefficient of 0.00 15 cm2 s-l across the chemocline. The upward diffusive loss of NH, added to the sedimentation rate of N and multiplied by the stoichiometric C : N ratio yields an organic carbon flux into the anoxic waters of 1,200 pmol C cm-2 yr-I, which is - 13% of the total primary productivity.
A Heat Shock Transcription Factor with Reduced Activity Suppresses a Yeast HSP70 Mutant

Strains carrying deletions in both the SSA1 and SSA2 HSP70 genes of Saccharomyces cerevisiae exhibit pleiotropic phenotypes, including the inability to grow at 37 degrees C or higher, reduced growth rate at permissive temperatures, increased HSP gene expression, and constitutive thermotolerance. A screen for extragenic suppressors of the ssa1 ssa2 slow-growth phenotype identified a spontaneous dominant suppressor mutation, EXA3-1 (R.J. Nelson, M. Heschl, and E.A. Craig, Genetics 131:277-285, 1992). Here we report that EXA3-1 is an allele of HSF1, which encodes the heat shock transcription factor (HSF). Strains containing the EXA3-1 allele in a wild-type background exhibit a 10- to 15-fold reduction in HSF activity during steady-state growth conditions as well as a delay in the accumulation of the SSA4, HSP26, and HSP104 mRNAs after a heat shock. EXA3-1-mediated suppression is the result of a single amino acid substitution of a highly conserved residue in the HSF DNA-binding domain which drastically reduces the ability of HSF to bind to heat shock elements as evaluated by band shift analysis. Together, these results indicate that the poor growth of ssa1 ssa2 strains is the result, at least in part, of the overproduction of a deleterious heat shock protein(s). This conclusion is supported by the fact that the levels of at least some heat shock proteins are reduced in ssa1 ssa2 cells containing the EXA3-1 allele. Surprisingly, strains containing the EXA3-1 allele in a wild-type HSP70 background grow early as well as the wild-type strain over a wide temperature range, displaying only a slight reduction in growth rate at 37 degrees Celsius, indicating that cells contain significantly more HSF activity than is require for growth under steady-state conditions.
Developing PFC representations using reinforcement learning

From both functional and biological considerations, it is widely believed that action production, planning, and goal-oriented behaviors supported by the frontal cortex are organized hierarchically [Fuster (1991); Koechlin, E., Ody, C., & Kouneiher, F. (2003). Neuroscience: The architecture of cognitive control in the human prefrontal cortex. Science, 424, 1181–1184; Miller, G. A., Galanter, E., & Pribram, K. H. (1960). Plans and the structure of behavior. New York: Holt]. However, the nature of the different levels of the hierarchy remains unclear, and little attention has been paid to the origins of such a hierarchy. We address these issues through biologically-inspired computational models that develop representations through reinforcement learning. We explore several different factors in these models that might plausibly give rise to a hierarchical organization of representations within the PFC, including an initial connectivity hierarchy within PFC, a hierarchical set of connections between PFC and subcortical structures controlling it, and differential synaptic plasticity schedules. Simulation results indicate that architectural constraints contribute to the segregation of different types of representations, and that this segregation facilitates learning. These findings are consistent with the idea that there is a functional hierarchy in PFC, as captured in our earlier computational models of PFC function and a growing body of empirical data.
Toward a Multicultural Positive Psychology: Indigenous Forgiveness and Hmong Culture

The growing field of positive psychology is encouraging advances in the scientific research of developmental strengths and virtues like forgiveness. However, multicultural and indigenous psychology perspectives can raise valuable questions about positive psychology and the relationship between cultural particularity and virtues like forgiveness. In this article, the authors consider the meaning of virtue in psychology and then focus on the culturally embedded nature of forgiveness as a virtue. They illustrate the value of an indigenous psychology approach by describing some of the dynamics related to conflict resolution and forgiveness in traditional Hmong culture. They then consider ways forgiveness research and intervention might need to be contextualized with Hmong Americans.