cssi/SciSciGPT-SciSciNet huggingface dataset:
Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31): alternatively spliced, functionally distinct isoforms expressed during mammalian cardiovascular development

The establishment of the cardiovascular system represents an early, critical event essential for normal embryonic development. An important component of vascular ontogeny is the differentiation and development of the endothelial and endocardial cell populations. This involves, at least in part, the expression and function of specific cell surface receptors required to mediate cell-cell and cell-matrix adhesion. Platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31) may well serve such a function. It is a member of the immunoglobulin superfamily expressed by the entire vascular endothelium in the adult. It is capable of mediating adhesion by a heterophilic mechanism requiring glycosaminoglycans, as well as by a homophilic, glycosaminoglycan independent, mechanism. It has been shown to regulate the expression of other adhesion molecules on naive T cells. This report documents by RT-PCR and immunohistochemical analysis the expression of PECAM-1 during early post implantation mouse embryo development. PECAM-1 was expressed by early endothelial precursors first within the yolk sac and subsequently within the embryo itself. Interestingly, embryonic PECAM-1 was expressed as multiple isoforms in which one or more clusters of polypeptides were missing from the cytoplasmic domain. The sequence and location of the deleted polypeptides corresponded to exons found in the human PECAM-1 gene. The alternatively spliced isoforms were capable of mediating cell-cell adhesion when transfected into L-cells. The isoforms differed, however, in their sensitivity to a panel of anti-PECAM-1 monoclonal antibodies. These data suggest that changes in the cytoplasmic domain of PECAM-1 may affect its function during cardiovascular development, and are consistent with our earlier report that systematic truncation of the cytoplasmic domain of human PECAM-1 resulted in changes in its ligand specificity, divalent cation and glycosaminoglycan dependence, as well as its susceptibility to adhesion blocking monoclonal antibodies. This is the first report of naturally occurring alternatively spliced forms of PECAM-1 having possible functional implications.
TPM activities at Motorola SCG America

Cost control, equipment lifespans, and productivity are concerns for all semiconductor manufacturers. Equipment purchase prices are aggressively spiraling upward. The pressure to reduce wafer manufacturing costs is relentless. Total Productive Maintenance is one form of relief that allows a manufacturer to wring the most return from the equipment set. Motorola is attempting to use this methodology to some degree. The Phoenix factory RFI has a three year history with the process. The current initiative is to implement TPM at the Group level at Motorola SCG.
Accelerated DSP functions on the CBE for the X-Midas Toolkit

We characterize the impact of the Cell Broadband Engine architecture, on commonly used radar DSP algorithms. We use the capabilities of the CBE to accelerate several key computational kernels including Matrix Multiplication, Matrix Inversion, and the Finite Impulse Response (FIR) filter. These algorithms are implemented and benchmarked as library routines within the X-Midas Toolkit. We observe speedups as large as 1200x for complex matrix multiplication, but speedups of 40x to 60x are more typical. We find that system I/O overhead within the X-Midas toolkit severely limited the performance of the applications.
Polybrominated diphenyl ethers enhance the production of proinflammatory cytokines by the placenta

Polybrominated diphenyl ether(s) (PBDE) are ubiquitous environmental contaminants that bind and cross the placenta but their effects on pregnancy outcome are unclear. It is possible that environmental contaminants increase the risk of inflammation-mediated pregnancy complications such as preterm birth by promoting a proinflammatory environment at the maternal-fetal interface. We hypothesized that PBDE would reduce IL-10 production and enhance the production of proinflammatory cytokines associated with preterm labor/birth by placental explants. Second-trimester placental explants were cultured in either vehicle (control) or 2 μM PBDE mixture of congers 47, 99 and 100 for 72 h. Cultures were then stimulated with 10(6) CFU/ml heat-killed Escherichia coli for a final 24 h incubation and conditioned medium was harvested for quantification of cytokines and PGE(2). COX-2 content and viability of the treated tissues were then quantified by tissue ELISA and MTT reduction activity, respectively. PBDE pre-treatment reduced E. coli-stimulated IL-10 production and significantly increased E. coli-stimulated IL-1β secretion. PBDE exposure also increased basal and bacteria-stimulated COX-2 expression. Basal, but not bacteria-stimulated PGE(2), was also enhanced by PBDE exposure. No effect of PBDE on viability of the explants cultures was detected. In summary, pre-exposure of placental explants to congers 47, 99, and 100 enhanced the placental proinflammatory response to infection. This may increase the risk of infection-mediated preterm birth by lowering the threshold for bacteria to stimulate a proinflammatory response(s).
Investigation of a 90Sr/90Y source for intra-ocular treatment of wet age-related macular degeneration.

Purpose: The purpose of this study is to perform an extensive investigation of an approximately 2.5 mm long {sup 90}Sr/{sup 90}Y source designed for treating wet age-related macular degeneration. Methods: As part of this investigation, a NIST-traceable absorbed dose to water calibration technique was established, and a source deployment verification test was developed. The influence of treatment cannula construction tolerance on the measurements as well as the dose delivered to the patient was investigated using the Monte Carlo code MCNP5. Variation between production cannulae was quantified experimentally using a well-type ionization chamber, and additional measurements along with Monte Carlo calculations of the collimating insert used for source deployment verification were performed to validate the model. Results: Maximum variation in the integrated target dose was seen when the source was shifted laterally within the treatment cannula. For the well chamber measurements, the observed standard deviation in ionization current for a single source placed in different reference cannulae was {+-}0.3%, with a maximum observed range of less than {+-}0.5%. Clinical cannulae in the collimating insert showed an average of 17.8%{+-}0.4% of the reference signal when sources were fully deployed compared to 18.5% predicted by Monte Carlo calculations. This discrepancy has been attributedmore » primarily to construction of the collimator since the collimation gap was observed to be approximately 0.025-0.075 mm smaller than specified. Construction tolerance of the well chamber insert as well as position tolerance of the cannula tip were both investigated, and their influence on the predicted signal was quantified. Additional measurements along with Monte Carlo based calculations of the collimating insert with polyethylene spacers added to the setup were performed to validate the Monte Carlo model. The shimmed Monte Carlo and measured data agree to within 1%, which is a magnitude difference of approximately 0.1% of the reference signal. Conclusions: This investigation confirms that the signal for an acceptably deployed source in the collimating insert is between 17.5% and 21.5% of the reference signal, as calculated using Monte Carlo models. Clinical cannulae for which the source deployment verification measurement falls outside the acceptable range should not be used to treat patients.« less
Necrotizing sialometaplasia-like change of the esophageal submucosal glands is associated with Barrett's esophagus.

The esophageal submucosal glands (SMG) protect the squamous epithelium from insults such as gastroesophageal reflux disease by secreting mucins and bicarbonate. We have observed metaplastic changes within the SMG acini that we have termed oncocytic glandular metaplasia (OGM), and necrotizing sialometaplasia-like change (NSMLC). The aim of this study is to evaluate the associated clinicopathological parameters of, and to phenotypically characterize the SMG metaplasias. Esophagectomy specimens were retrospectively assessed on hematoxylin and eosin sections and assigned to either a Barrett’s esophagus (BE) or non-BE control group. Clinicopathologic data was collected, and univariate analysis and multivariate logistic regression models were performed to assess the adjusted associations with NSMLC and OGM. Selected cases of SMG metaplasia were characterized. SMG were present in 82 esophagi that met inclusion criteria. On univariate analysis, NSMLC was associated with BE (p = 0.002). There was no relationship between NSMLC and patient age, sex, tumor size, or treatment history. OGM was associated with BE (p = 0.031). No relationship was found between OGM and patient age, sex, or tumor size. On multivariate analysis, BE was independently associated with NSMLC (odds ratio [OR] 4.95, p = 0.003). Treatment history was also independently associated with OGM (p = 0.029), but not NSMLC. Both NSMLC and OGM were non-mucinous ductal type epithelia retaining a p63-smooth muscle actin co-positive myoepithelial cell layer. NSMLC and OGM were present in endoscopic mucosal resection specimens. Our study suggests that SMG metaplasia is primarily a reflux-induced pathology. NSMLC may pose diagnostic dilemmas in resection specimens or when only partially represented in mucosal biopsies or endoscopic resection specimens.
β-aminoglutaric acid is a major soluble component of Methanococcus thermolithotrophicus

Abstract 13 C- and 15 N-NMR spectroscopy have been used to identify β-aminoglutaric acid (β-glutamic) as a major soluble component of the thermophilic, autotrophic marine methanogen Methanococcus thermolithotrophicus . This rare, non-protein amino acid has been recognized as a major dissolved free amino acid in marine sediments, but the microorganism responsible for its production has not previously been identified. The concentration of β-aminoglutarate (β-glutamate) is about one half that of free α-glutamate and increases (relative to the α-isomer) as cells enter the stationary phase. Analysis of the 13 C label distribution in a 13 CO 2 -pulse/ 12 CO 2 -chase experiment shows that label enters the β-aminoglutarate pool after it has decayed from other small soluble molecules. This implies that β-aminoglutarate is a catabolic product of the cells. Preliminary biosynthesis studies with labeled precursors indicate that only a single acetate moiety is incorporated in this unusual compound. This information is used to suggest possible biosynthetic pathways.
STABILITY AND ENZYMATIC PROPERTIES OF β‐GALACTOSIDASE FROM KLUYVEROMYCES FRAGILIS

Kluyveromyces fragilis β-galactosidase purified to electrophoretic, chromatographic and immunochemical homogeneity was used. The enzyme specifically required potassium ions for stability; MnCl2 increased the stability. The enzyme was maximally stable at pH 6.5 to 7.5; stability was markedly less at pH's below 6.5 and above pH 8.5 at 37°C. Temperature denaturation followed first order kinetics with an activation energy for denaturation of 56 kcal/mol. Maximum activity was achieved in the presence of 5mM KCl. In potassium phosphate buffer, the enzyme was further activated by Mn2+, Mg2+, Co2+ and Zn2+; Mn2+, at 0.1 mM, gave the highest activation. None of these ions activated the enzyme in Tris buffer and> 0.1 mM Zn2+ caused complete loss of activity. Activity was completely inhibited by ethylenediaminetetraacetate and partially restored by addition of MnCl2. p-Chloromercuribenzoate caused rapid loss of activity which could be restored by dithiothreitol. Iodoacetamide, N-ethylmaleimide and sodium tetrathionate did not inactivate the enzyme. The enzyme was specific for β-galactosides. Km's for o-nitrophenyl β-D-galactopyranoside and lactose were 2.72 and 13.9 mM, respectively, at pH 6.6 D-Galactono-1, 4-lactone was a good competitive inhibitor (Ki=0.17 mM). pH optimum for hydrolysis of o-nitrophenyl β-D-galactopyranoside was 6.2–6.4. Vmax for this substrate was dependent on two ionizable groups of pKa of 6.13 and 6.51 while Vmax/Km was dependent on two ionizable groups of pKa of 6.39 and 7.23. Activation energy for hydrolysis of o-nitrophenyl β-D-galactopyranoside at pH 7.0 was 9.1 kcal/mol in the range 20–40°C.
Differential sorption in glassy polymers

Anomalous sorption curves have often been observed for differential sorption experiments in glassy polymers. A model is proposed to describe this non-Fickian behavior. This model is based on the presence of interfacial resistance caused by slow rate processes at the phase boundary. Predictions of the model are compared with general experimental observations.
Using the internet to communicate during a crisis

Purpose – The purpose of this paper is to discuss how the internet is influencing and changing communication practices utilized during a crisis.Design/methodology/approach – Provides an overview of communication practices during recent disasters.Findings – Discusses the need for disaster management responses to change in order to capitalize on the technology.Originality/value – This paper is a useful source of information about now the internet is influencing and charging communication practices.
Effects of automated transfer coalescing on production physics

Abstract Diverse lattice gauge applications coded using the Canopy paradigm (augmented by transfer coalescing techniques) have been making effective use of the 50 Gflop ACPMAPS system at Fermilab for heavy-quark physics. These investigations have uncovered neccessities and limitations beyond the unusual CPU-Memory-Communications triad. Mass storage bandwith and system robustness requirements are discussed in light of this experience.
Comparative Analysis of the Calculation Results of Online Short-Circuit Current Based on PSASP and Fault Wave Recording

In daily operation process,the results of online short-circuit current calculation and fault wave recording is different, the differences between the two results affected the dispatcher’s decision. In-depth analysis of the calculation process and finding the possible causes of the differences should be done. The on-line PSASP short-circuit current calculation based on power flow and scheme was studied. The boundary conditions and calculation models of two methods were studied, the influence of the modeling scope and equivalent circuits to the short-circuit current was also studied. Fault wave recording calculated short-circuit current through forward calculation, the middle to both sides calculation and backward calculation, and the differences of the three calculation mode were also analyzed. Through the above analysis and comparison, online data equivalent to 220kV high voltage side of the transformer greatly impacts short-circuit current, but effective value calculation method of fault wave recording has a little impact on the short-circuit current, mainly in the following reasons, the first one is that non-dispatching power plant is equivalent to a load, the second one is that several different types of load is equivalent to a load using one load model, the third one is that all devices connecting to low voltage side of the 220kV transformers are equivalent to 220kV. Conclusions of the analysis can provide the basis for the practical work of online short-circuit current calculation.
Current and Past Depression as Predictors of Family Functioning : A Comparison of Men and Women in a Community Sample

The association between family functioning and parental depression has primarily been studied in samples of women. In particular, very little research exists that examines how parent gender and past diagnoses of depression are related to family functioning. The family relationships of 469 couples from a community sample were examined using self- and partner report measures of the marital relationship and youth report and interviewer-rated measures of the parent-youth relationship. Both currently and formerly depressed men and women were shown to have poorer family functioning than nondepressed and never depressed individuals, respectively. Interactions of gender and depression status indicated that depression and poorer marital functioning were more strongly related for women than for men, but there were few gender differences in the parent-youth relationship. The results highlight the need for further research on men's family functioning and suggest that targeting current depressive symptoms in treatment may not be sufficient to resolve marital and parent-youth difficulties that endure after depressive episodes remit.
3α-hydroxysteroid dehydrogenase activity in rat liver and skin

3 alpha-Hydroxysteroid dehydrogenase (3 alpha HSD) is one of the main enzymes involved in the metabolism of the active androgen, dihydrotestosterone (DHT). 3 alpha HSD catalyzes the reversible reduction of DHT to 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha DIOL). The equilibrium of 3 alpha HSD reductive and oxidative activity is an important factor in the regulation of intracellular levels of DHT. In this study, we determined the kinetic characteristics of 3 alpha HSD in the subcellular fractions of female rat liver and abdominal skin. The enzyme expressed its activity in the cytosol and microsomal fractions of both of these tissues. It showed higher activity with the phosphorylated cofactors, NADPH and NADP, and was inhibited by indomethacin. The Vmax values of 3 alpha HSD in the cytosol were 10-fold higher than the Vmax values in the microsomes in both the liver and skin. In both tissues, the Km values with DHT as the substrate (reductive) were lower than the Km with 3 alpha DIOL as the substrate (oxidative). Although the Vmax values of the oxidative reaction were higher than the Vmax values of the reductive reaction in both liver and skin, the low Km values and the higher Vmax/Km ratio for DHT indicated that the reduction of DHT to 3 alpha DIOL was the favored reaction. The enzyme kinetics of 3 alpha HSD suggest that neither tissue accumulates DHT, but promptly converts it to 3 alpha DIOL.(ABSTRACT TRUNCATED AT 250 WORDS)
A SPECTRAL STUDY OF Cu2+ AND Cd2+ WITH A SUBSTITUTED PYRAZINE LIGAND

Abstract We wish to report a novel ligand that forms an intense blue to purple color when complexed with various non-transition as well as transition metals. This color appears when Cd2+, Zn2+, Ag1+, Mg2+ Fe2+, Fe3+, Cu2+, Co2+, Ni2+, or Mn2+ is added to N,N′-bis(4-N″,N″-dimethylanilinyl)-2,5-bis(methylenimino)pyrazine (Figure 1) which is dissolved in dimethylformamide (DMF). The ligand is capable of being multidentate; therefore, spectro-photometric titration experiments were performed using Cd2+ in one experiment and Cu2+ in another experiment. If these ions can be considered as being representative of the non-transition and transition complexes respectively, then the stoichiometry is 1:1 and 2:1 (metal:ligand). Whether this sampling is truly representative is under further investigation.
Flight performance of a high resolution, high data rate solar ultraviolet telescope and spectrograph

Abstract The High Resolution Telescope and Spectrograph (HRTS) instrument has been flown three times on sounding rockets and has dramatically demonstrated the value of high resolution (spectral, spatial, and temporal) coupled with wide spectral and spatial coverage. Through the use of film as a detector, the HRTS can capture a large spectral and spatial range simultaneously. Because of the high spectral and spatial resolution, each exposure contains 10 million data points. After digitizing, this equates to a data collection rate of four megabits per second for a 20 second exposure. Because of the large film format, a set of HRTS exposures has recorded complete profiles of over 2800 emission lines simultaneously at 1000 different locations on the Sun. These emission lines originate in temperature regimes ranging from the temperature minimum to the corona. This allows a statistical analysis of temperature, pressure, density and velocity in many layers of the solar atmosphere.
Texture development during deformation processing of the n-type bismuth telluride alloy Bi2Se0.3Te2.7

Abstract The n-type bismuth telluride alloy Bi 2 Se 0.3 Te 2.7 was subject to hot deformation under several deformation conditions, such as extrusion, sandwich rolling, and plane strain compression. The resulting crystallographic texture is found to depend on the initial texture, strain imposed during deformation, the type of deformation, and proximity to the die surface. Bismuth telluride has a trigonal crystal structure, based on a hexagonal lattice with a c / a ratio of 6.96. During rolling, the material develops a rolling fiber texture in which the [0001] is oriented perpendicular to the rolling plane and the 〈 11 2 ¯ 0 〉 directions are randomly oriented in the plane of rolling. This texture is typically observed in a low c / a ratio material like magnesium. Measurement of the thermoelectric transport properties indicate that n-type bismuth telluride with a rolling fiber texture can have a non-dimensional figure of merit ZT of almost 1 at room temperature.
Effect of timing of initiation of adjuvant chemotherapy on disease-free survival in breast cancer.

Four hundred and sixty patients with stage II or III breast cancer following regional therapy were treated with an adjuvant combination chemotherapy consisting of fluorouracil, doxorubicin, and cyclophosphamide (FAC). The relationship between the length of disease-free survival and length of delays in initiation of chemotherapy after surgery was evaluated. Patients were divided into four subgroups according to the length of delay in initiation of chemotherapy (< 10 weeks, 10–13, 14–17, and ≥ 18 weeks). Overall four year diseasefree survival was 64%, 68%, 60%, and 63% for patient groups with delays of < 10 weeks, 10–13, 14–17, or ≥ 18 weeks respectively (p = 0.39). There was no trend for longer delay in treatment to be associated with shorter disease-free survival, except in poor prognosis patients.
Labor and Post-Fordist Industrial Restructuring in East and Southeast Asia

By a variety of measures, East Asian trade unionism remains numerically weak and politically ineffectual despite continuing industrial deepening in the region. Although political explanations go some distance in explaining this weakness, the new competitive strategies of firms have played an increasingly important role in undercutting and preempting organized labor. This article explores the impact of new strategies of flexible production, and of their developmental timing, for emergent labor movements across the region.
Keeping Up with the Joneses: The Interplay of Personal and Collective Evaluations in Voter Turnout

Do citizens turnout to vote because of changes in their personal financial situation or are they influenced by the nation’s economic performance? Previous research on this question is far from united. We attempt to unify the disparate literature on the effects of pocketbook and sociotropic evaluations on voter turnout in midterm and presidential elections. Our analysis of ANES data from 1978 to 2004, based on a reference-dependent model of voter turnout, indicates that both pocketbook and sociotropic considerations affect individuals’ decision of whether to vote in midterm elections. Those who perceive that over the last year their own financial situation has improved relative to the economy are less likely to vote than those who view the economy as outperforming their own financial situation.
Femtosecond infrared probing of biomolecules

Recent infrared spectroscopic studies of the ultrafast responses of optically triggered changes in proteins are discussed. Examples from research on ions in aqueous media, hemoglobin, bacteriorhodopsin, and reaction centers illustrate the potential of time resolved infrared spectroscopy in the field of protein dynamics.
The impact of science curricula on student views about the nature of science

This review of the literature focused on three decades of research related to precollege student understandings about the nature of science. Various interpretations of what aspects characterize the nature of science were examined, revealing an agreement among scientists, science educators, and those involved in policy-making arenas that the nature of science is multifaceted and an important component of scientific literacy. A summary of the research regarding the adequacies of student conceptions about the nature of science revealed inconsistent results. Although the majority of studies show that student understandings are less than desirable, there is research that indicates that student conceptions are acceptable. Research on the impact of instructional materials and techniques on student understandings was also reviewed. The effects of language in science instruction, the content emphasis of instructional materials, integrated science curricula, and instruction in general were curricular variables found to have a negative impact on student understandings about the nature of science. Empirical evidence about the success of innovative instructional materials and techniques designed to facilitate more adequate understandings of the nature of science is needed.
Identification of compounds in an HPLC fraction from female extracts that elicit mating responses in male screwworm flies,Cochliomyia hominivorax.

When hexane extracts of mature screwworm females were chromatographed on a silica gel column, mating stimulant activity was concentrated in a fraction that eluted with hexane-ether (94∶6, v/v). Separation of this fraction with HPLC (acetonitrile-acetone; 60∶40, isocratic) resulted in a chromatogram of some 20 peaks. Only peaks 4–11 elicited mating responses. Peaks 5–10 had most of the activity, with peak 8 producing the highest response. Sixteen compounds were characterized from peak 8 by gas chromatography-mass spectrometry: six unbranched secondary acetates (C31H62O2); seven previously unreported methyl-branched secondary acetates (C32H64O2); one unbranched ketone (C31H62O); and one methyl-branched ketone (C32H64O). The isomeric acetates were not completely resolved from each other by capillary gas chromatography (CGC) on methyl silicone columns. The sixteenth compound was an aldehyde (C30H60O) that was present only in occasional peak 8 preparations. These compounds and several derivatives were characterized by capillary gas chromatography-mass spectrometry (CGC-MS). The position of the acetate group was ascertained by conversion to a keto group or by replacement of the acetate with a methyl group. Pheromone activity was not observed in peaks trapped either from CGC or by recombination of the trapped CGC peaks from HPLC peak 8. This apparent loss of activity from CGC peaks or from TLC cannot currently be explained.
Sounding the Occupation: Joe Sacco's Palestine and the Uses of Graphic Narrative for (Post)Colonial Critique

Working at the intersection of postcolonial literary studies and comics narratology, this paper argues that Joe Sacco’s graphic narrative Palestine contributes a spatial and sonic record of territorial occupation to the Palestinian national narrative. Sacco utilizes the comics form to represent the complex of physical borders and spatial narratives he encounters in the Occupied Palestinian Territories. Further, he renders graphically the epiphenomenal sonic regime resulting from spatial management. Rather than an absence or gap in the Palestinian narrative, Sacco understands spatialized sound as a presence, a marker of materiality. Ultimately, Palestine suggests the rich potential of the comics form for postcolonial literary studies. Sacco’s graphic narrative reinvigorates the field’s engagement with literary representations of Israel-Palestine by demonstrating the continued utility of the (post)colonial paradigm and by challenging the fields’ scholars to forge new interdisciplinary linkages to comics studies.
An Analysis of Hamster Afferent Taste Nerve Response Functions

Sensitivities to moderately intense stimuli representing four taste qualities to man were determined for 79 hamster chorda tympani fibers. Some fibers were very sensitive to sucrose, sodium chloride, or hydrochloric acid, but none were very sensitive to quinine. These sensitivities were not randomly distributed among fibers: the sucrose sensitivity was separated from and negatively correlated with the other sensitivities which were associated and positively correlated with each other. Moreover, there were a limited number of sensitivity patterns: (a) fibers responding best to sucrose responded second-best to salt, less to acid, not to quinine; (b) fibers responding best to salt either responded second-best to sucrose and not to acid or quinine; or second-best to acid, less to quinine, and not to sucrose; and (c) fibers responding best to acid responded second-best to salt, more to quinine, and less to sucrose than other fibers. Therefore, if four stimuli of different taste qualities are ordered from acceptable to unacceptable, neural response functions of most hamster chorda tympani taste fibers peak at one point. Sensitivities to nine other moderately intense stimuli which vary in quality to man were also determined for 46-49 of the fibers. Sensitivities to sweet stimuli were always associated with each other and separated from sensitivities to nonsweet stimuli. Sensitivities to nonsweet stimuli were all associated with each other; however, the strongest correlations were between sensitivities to stimuli of like quality, e.g., the three acids or the two sodium salts.
Recognition of the product of a novel MHC TL region gene (27b) by a mouse γδ T cell receptor

The gamma delta T cell receptor (TCR) derived from the mouse KN6 T cell hybridoma recognizes an autologous determinant encoded by a broadly expressed gene mapping in the TL region of the major histocompatibility complex (MHC). We have cloned the gene and demonstrated that it is a novel class I gene (designated 27b) belonging to a hitherto undescribed TL region gene cluster in strain C57BL/6. The BALB/c allele of 27b, gene T17c, is defective because it lacks an appropriate splice acceptor site, which explains the lack of recognition of BALB/c stimulator cells by the KN6 cells. We propose that gamma delta TCR and nonclassical MHC and MHC-related class I molecules have coevolved to recognize a conserved set of endogenous and foreign determinants.
Probing medium-range structural correlations by fluctuation microscopy

We outline recent advances in the fluctuation microscopy technique for probing medium-range structural correlations in disordered materials. The technique was originally developed for electron microscopy, but has now been extended to optical and x-ray microscopies. We show that fluctuation microscopy can detect trace quantities of C60 in a disordered graphite matrix, even though the diffraction signature from the C60 is essentially undetectable. This result indicates that the technique can be used to discern dilute distributions of macromolecules in an otherwise disordered matrix. We also report preliminary studies of interferometric fluctuation microscopy using cross-correlations in diffraction between coherent double probes. This is a form of holography where the diffraction patterns from two neighboring regions are allowed to overlap and interfere. Young's fringes appear wherever both regions scatter strongly. The cross-correlation can be examined as a function of probe separation to estimate a structure correlation length. This method holds much promise for studying medium-range order, since it isolates the essential four-body terms underpinning the fluctuation microscopy technique.
Extended zero-core-contribution model applied to multichannel photodetachment

The zero-core-contribution model is extended to calculate absolute photodetachment cross sections taking into account the fine-structure levels and higher electronic states of the anions and neutral atoms. Comparisons are made with experimental data involving 20 different anions with $p$ outermost occupied orbitals. Very good agreement is obtained.
Effects of lifelong dietary exposure to genistein or nonylphenol on amphetamine-stimulated striatal dopamine release in male and female rats

Estrogen modulates baseline and amphetamine-stimulated dopamine (DA) release in the adult female rat striatum. The isoflavone found in soybeans, genistein, is a phytoestrogen and may have comparable effects on striatal DA levels. Similarly, the industrial intermediate and potential endocrine disrupter, para-nonylphenol, has estrogen-like effects. Here, Sprague-Dawley rats were continuously exposed to phytoestrogen-free diets containing 0, 100, or 500 ppm genistein (Experiment 1) or 0 or 200, or 750 ppm nonylphenol (Experiment 2) beginning at conception and continuing throughout. To eliminate estrous cycle influences on DA levels, females were ovariectomized at adulthood. As adults, striatal levels of DA and its metabolites [3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)] were measured in unanesthetized male and female rats via cerebral microdialysis before and for 200 min after an intraperitoneal injection of 2 mg/kg D-amphetamine. Although baseline 5-hydroxyindoleacetic acid (5-HIAA) levels indicated an isolated effect in genistein-treated females, there were no meaningful differences among treatment groups in baseline levels of DA, DOPAC, or HVA. However, dietary exposure to 500 ppm genistein significantly potentiated amphetamine-stimulated DA release in males and a similar trend was apparent, but not statistically significant, in females. Dietary exposure to 200 or 750 ppm nonylphenol had no significant effects in males or females. These results suggest that dietary genistein exposure may act similarly to estradiol in augmenting amphetamine-stimulated DA release.
Medical students and comprehensive patient care: attitudes, perceived competence and demonstrated ability.

Summary. The importance of medical training which emphasizes comprehensive, biopsychosocial medical care is increasingly recognized. Research has focused on characteristics affecting attitudes toward psychosocial information, inferring that such attitudes are acceptable surrogates for demonstrated ability. The current study evaluates the accuracy of information elicited during medical interviews conducted by medical students. Information regarding patient compliance, patient income and patient reliance on social support was correlated with student characteristics, attitudes toward psychosocial information and self-perceived competence in eliciting such data. For 36 third-year medical students on a 4-week family medicine rotation, results showed that measures of psychosocial attitudes were not an acceptable substitute for demonstrated ability. Exposing medical students to the importance of psychosocial data is valuable, but additional attention must be given to their eliciting such information accurately and efficiently.
Poliovirus replicons encoding the B subunit of Helicobacter pylori urease elicit a Th1 associated immune response.

The development of a vaccine for Helicobacter pylori is a key strategy for reducing the worldwide prevalence of H. pylori infection. Although immunization with recombinant B subunit of H. pylori urease (ureB) has yielded promising results, for the most part, these studies relied on the use of strong adjuvant, cholera toxin, precluding the use in humans. Thus, the development of new vaccine strategies for H. pylori is essential. Previous studies from our laboratory have described a vaccine vector based on poliovirus in which foreign genes are substituted for the poliovirus capsid genes. The genomes encoding foreign proteins (replicons) are encapsidated into authentic poliovirions by providing the capsids in trans. To test the utility of replicons as a vaccine vector for H. pylori, a replicon was constructed which encodes ureB. Expression of ureB in cells from the replicon was demonstrated by metabolic labeling followed by immunoprecipitation with anti-urease antibodies. To investigate the immunogenicity of the replicons, mice containing the transgene for the receptor for poliovirus were immunized via the intramuscular route. Mice given three doses of replicons did not develop substantial antibodies to ureB as determined by Western blot analysis using lysates from H. pylori. In contrast, mice given two doses of replicon followed by a single injection of recombinant ureB developed serum antibodies to ureB which were predominately IgG2a. Splenic lymphocytes from mice immunized with replicons alone, or replicons plus recombinant ureB produced abundant interferon-γ and no detectable interleukin-4 upon stimulation with recombinant ureB. These results establish that poliovirus replicons encoding H. pylori ureB are immunogenic and induce primarily a T helper 1 associated immune response.
Use of ion-exchange chromatography in the spectrophotometric assay for the antineoplastic agent, hexamethylmelamine, in biological fluids

Abstract A new, simple, rapid, and precise method for the determination of hexamethylmelamine in human whole blood, plasma, and urine has been described. The method is based upon preliminary column chromatography on onion- and cation-exchange resins followed by ultraviolet absorption spectrophotometry.
Competition theory, evolution, and the concept of an ecological niche

This article examines some of the main tenets of competition theory in light of the theory of evolution and the concept of an ecological niche. The principle of competitive exclusion and the related assumption that communities exist at competitive equilibrium - fundamental parts of many competition theories and models - may be violated if non-equilibrium conditions exist in natural communities or are incorporated into competition models. Furthermore, these two basic tenets of competition theory are not compatible with the theory of evolution. Variation in ecologically significant environmental factors and non-equilibrium in population numbers should occur in most natural communities, and such changes have important effects on community relations, niche overlap, and the evolution of ecosystems. Ecologists should view competition as a process occurring within a complexdynamic system, and should be wary of theoretical positions built upon simple laboratory experiments or simplistic mathematical models. In considering the relationship between niche overlap and competition, niche overlap should not be taken as a sufficient condition for competition; many factors may prevent or diminish competition between populations with similar resource utilization patterns. The typically opposing forces of intraspecific and interspecific competition need to be simultaneously considered, for it is the balance between them that in large part determines niche boundaries.
UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase of Escherichia coli is a zinc metalloenzyme.

The enzyme UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc deacetylase (LpxC) catalyzes the committed step in the biosynthesis of lipid A and is therefore a potential antibiotic target. Inhibition of this enzyme by hydroxamate compounds [Onishi, H. R.; Pelak, B. A.; Gerckens, L. S.; Silver, L. L.; Kahan, F. M.; Chen, M. H.; Patchett, A. A.; Stachula, S. S.; Anderson, M. S.; Raetz, C. R. H. (1996) Science 274, 980−982] suggested the presence of a metal ion cofactor. We have investigated the substrate specificity and metal dependence of the deacetylase using spectroscopic and kinetic analyses. Comparison of the steady-state kinetic parameters for the physiological substrate UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc and an alternative substrate, UDP-GlcNAc, demonstrates that the ester-linked R-3-hydroxymyristoyl chain increases kcat/KM (5 × 106)-fold. Metal-chelating reagents, such as dipicolinic acid (DPA) and ethylenediaminetetraacetic acid, completely inhibit LpxC activity, implicating an essential metal ion. Plasma em...
Environmental Reform Organizations and Undone Science in the United States: Exploring the Environmental, Health, and Safety Implications of Nanotechnology

Environmental organizations have raised concerns about the environmental, health, and safety (EHS) implications of the hundreds of products containing nanomaterials that are now on the market. In the process they have drawn attention to the ‘undone science’ of EHS research and called for changes in both research and regulatory policy. Environmental and other advocacy organizations have been active in three policy fields in the United States: funding levels for EHS research, moratoria on the production of new nanomaterials largely based on the precautionary principle, and negotiations over definitions of safe or responsible nanotechnology with the private sector and the federal government. During the administration of President George W. Bush, calls for more research and industry guidelines met with greater success than those that called for moratoria and enhanced mandatory regulation. The more successful strategies tend to reproduce scientistic politics associated with risk assessment, whereas the less su...
Parasitoids and parasites of Polistes metricus Say (Hymenoptera: Vespidae) in northeast Georgia

Abstract The strepsipteran Xenos peckii Kirby, the ichneumonid Pachysomoides fulvus Cresson, the pyralid Chalcoela pegasalis Walker, and the eulophid Elasmus polistis Burks were recorded from 303 Polistes metricus Say early season colonies collected from northeast Georgia during 1997–2000. Colonies of P. metricus were significantly more likely to be infested by X. peckii than by P. fulvus, C. pegasalis, or E. polistis. Both X. peckii and C. pegasalis infested colonies more frequently when either eggs, larvae, and pupae or only larvae and pupae were present in the nest.
THE FIRST COMPUTATIONAL THEORY OF MIND AND BRAIN: A CLOSE LOOK AT MCCULLOCH AND PITTS'S ''LOGICAL CALCULUS OF IDEAS IMMANENT IN NERVOUS ACTIVITY''

Despite its significance in neuroscience and computation, McCulloch and Pitts's celebrated 1943 paper has received little historical and philosophical attention. In 1943 there already existed a lively community of biophysicists doing mathematical work on neural networks. What was novel in McCulloch and Pitts's paper was their use of logic and computation to understand neural, and thus mental, activity. McCulloch and Pitts's contributions included (i) a formalism whose refinement and generalization led to the notion of finite automata (an important formalism in computability theory), (ii) a technique that inspired the notion of logic design (a fundamental part of modern computer design), (iii) the first use of com- putation to address the mind-body problem, and (iv) the first modern computational theory of mind and brain.
Statistical damage analysis of transverse cracking in high temperature composite laminates

High temperature polymer composites are receiving special attention because of their potential applications to high speed transport airframe structures and aircraft engine components exposed to elevated temperatures. In this study, a statistical analysis was used to study the progressive transverse cracking in a typical high temperature composite. The mechanical properties of this unidirectional laminate were first characterized both at room and high temperatures. Damage mechanisms of transverse cracking in cross-ply laminates were studied by X-ray radiography at room temperature and in-test photography technique at high temperature. Since the tensile strength of unidirectional laminate along transverse direction was found to follow Weibull distribution, Monte Carlo simulation technique based on experimentally obtained parameters was applied to predict transverse cracking at different temperatures. Experiments and simulation showed that they agree well both at room temperature and 149 °C (stress free temperature) in terms of applied stress versus crack density. The probability density function (PDF) of transverse crack spacing considering statistical strength distribution was also developed, and good agreements with simulation and experimental results are reached. Finally, a generalized master curve that predicts the normalized applied stress versus normalized crack density for various lay-ups and various temperatures was established.
Is there an unusual solar core

Various attempts have been made in the past two decades to determine the properties of the core of the Sun, by measurements of solar neutrino radiation, the distortion of the solar gravitational potential and frequency splittings of solar oscillation modes. In the latter category, the two best measurements have been made by Duvall and Harvey1 and by Brown2; both showed splitting roughly independent of spherical harmonic degree l, and both had a peculiar peak in the measured splitting at l = 11. We present here new results, based on the analysis of 6,656 individual oscillation modes for 5 ≤ l ≤ 20. These data yield a splitting spectrum which is consistent with previous measurements, but without the unusual peak at l = 11, thus suggesting that a simple standard model for the solar core is essentially correct.
Significance for the Sake of Significance: The Relevance of Statistical Data

Statistical tests are important tools in assessing the outcomes of clinical research studies. Although the appropriate application of statistics is fundamental to the interpretation and presentation of scientific data, the literature is awash with examples of basic statistical errors and inappropriate analyses. In addition, consideration should always be given to the clinical impact of statistical data. There is a risk of focusing too heavily on statistical significance without full appreciation of the potentially broader clinical significance of results. This report, based on a recent article in Nature by David L. Vaux (1), briefly discusses the inappropriate use of basic statistics and highlights the concept of statistical vs clinical significance. ### THE BIG ISSUE Unfortunately, many science graduates go …
Counterexamples to a conjecture about Petersen-minors in supersnarks

Abstract In this note counterexamples to a conjecture of Chetwynd and Wilson (Snarks and supersnarks, in: Chartrand et al. (Eds.), The Theory and Applications of Graphs. (Kalamazoo, MI, 1980), Wiley, New York, 1981, pp. 215–241) are constructed.
Myelinoclastic Diffuse Sclerosis (Schilder's Disease): Report of a Case and Review of the Literature:

The clinical, neuroimaging, and neuropathologic features of Schilder's disease in a 17-year-old girl are presented and compared to 11 well-documented cases reported since 1912. The evolution of knowledge about Schilder's disease and the confusion in nomenclature are reviewed. Signs and symptoms in this case and others reported in the literature are nonspecific and may mimic mass lesions. Neuroimaging studies also may mimic brain tumor or abscess; however, the absence of significant edema, the irregular and incomplete ring enhancement, the discrepancy between size of the lesions and the associated mass effect, and the absence of other lesions elsewhere in the brain may help differentiate Schilder's disease from neoplasm, infection, and other demyelinating lesions. Although frozen sections of these lesions are often interpreted as astrocytoma, the inflammatory, primarily histiocytic, nature of Schilder's disease is more easily recognized in paraffin-embedded material. Unique features of this case include multiple unilateral lesions and the cyst-like degeneration present in both lesions. Multiple lesions in Schilder's disease are characteristically bilateral. The examination of aspirated fluid is the first such report in Schilder's disease. The limitation of multiple lesions in our case to one hemisphere calls for reexamination of the restrictive 1985 criteria of Poser for the diagnosis of Schilder's disease.