cssi/SciSciGPT-SciSciNet huggingface dataset:
Lipid modifications of G protein subunits.: Myristoylation of Goα increases its affinity for βγ

Myristoylated recombinant proteins can be synthesized in Escherichia coli by concurrent expression of the enzyme myristoyl-CoA:protein N-myristoyl-transferase with its protein substrates (Duronio, R.J., Jackson-Machelski, E., Heuckeroth, R.O., Olins, P. O., Devine, C.S., Yonemoto, W., Slice, L. W., Taylor, S. S., and Gordon, J. I. (1990) Proc. Natl. Acad. Sci. U. S.A. 87, 1506-1510). Expression of the G protein subunit Goα in this system results in the synthesis of two forms of the protein; these were separated on a column of heptylamine-Sepharose. Purification of the more abundant form of Goα yielded a product that has a blocked amino terminus. Chemical analysis of the fatty acids released by acid hydrolysis of the protein revealed myristic acid. The second form of the protein was not myristoylated. Myristoylated and nonmyristoylated recombinant Goα were compared with brain Goα (which is myristoylated) for their ability to interact with G protein βγ subunits. The nonmyristoylated recombinant protein clearly had a reduced affinity for βγ, while the myristoylated recombinant protein was indistinguishable from native Goα in its subunit interactions. Thus, myristoylation increases the affinity of α subunits for βγ. We propose that the function of myristoylation of G protein α subunits is, at least in part, to facilitate formation of the heterotrimer and the localization of α to the plasma membrane.
Results of the Salish Projects: Summary and Implications for Science Teacher Education.

Science teaching and teacher education in the U.S.A. have been of great national interest recently due to a severe shortage of science (and mathematics) teachers who do not hold strong qualifications in their fields of study. Unfortunately we lack a rigorous research base that helps inform solid practices about various models or elements of teacher preparation (Allen, 2003; Futrell, 2010; Sykes, Bird, & Kennedy, 2010; Wang, Odell, Klecka, Spalding & Lin, 2010). In reviewing research on science teacher education, Anderson and Mitchener (1994) found that “there is only a small amount of research on pre-service education and what does exist is rather limited in scope and usefulness” (p. 28). A broader review of 37 studies in teacher preparation in general conducted for the U.S. Department of Education (Wilson, Floden, & Ferrini-Mundy, 2001) concluded that “there is no research that directly assesses what teachers learn in their pedagogical preparation or that evaluates the relationship of pedagogical knowledge to student learning or teacher behavior” (p. 12). There have not been enough studies completed of sufficient quality in teacher preparation - in any subject matter area - to provide a confident sense of “what works” and why it works (Allen, 2003). Many studies in teacher preparation are case studies or very limited sample size investigations which make generalizations to theory applicable only to these samples, and comparisons among similar populations or programs very problematic (for a more comprehensive review, refer to the Handbook of Research on Science Education edited by Abell & Lederman, 2007).
Comorbidity of Gender Dysphoria and Other Major Psychiatric Diagnoses

Previous studies suggest that many transsexuals evidence an Axis I diagnosis according to the DSM-IV classification (e.g., psychoses, major affective disorder). The current study examined retrospectively the comorbidity between gender dysphoria and major psychopathology, evaluating the charts of 435 gender dysphoric individuals (318 male and 117 female). AH had undergone an extensive evaluation, addressing such areas as hormonal/surgical treatment, and histories of substance abuse, mental illness, genital mutilation, and suicide attempts. In addition, a subgroup of 137 individuals completed the MMPI. Findings revealed over two thirds were undergoing hormone reassignment, suggesting a commitment to the real-life cross-gender process. One quarter had had problems with substance abuse prior to entering treatment, but less than 10% evidenced problems associated with mental illness, genital mutilation, or suicide attempts. Those completing the MMPI (93 female and 44 male) demonstrated profiles that were notably free of psychopathology (e.g., Axis I or Axis II criteria). The one scale where significant differences were observed was the Mf scale, and this held true only for the male-to-female group. Psychological profiles as measured by the MMPI were more “normal” in the desired sex than the anatomic sex. Results support the view that transsexualism is usually an isolated diagnosis and not part of any general psychopathological disorder.
Bioinformatics--Trying to Swim in a Sea of Data

The massive quantities of data generated by genomic research have given rise to the field of bioinformatics--an emerging discipline that seeks to integrate computer science with applications derived from molecular biology. Roos identifies two major challenges to the advancement of bioinformatics research: how to define permissible use of data released to the community before publication, and restrictions on the further analysis and reposting of published data available on proprietary Web sites.
Influence of Glass Property Restrictions on Hanford HLW Glass Volume

A systematic evaluation of Hanford High-Level Waste (HLW) loading in alkali-alumino-borosilicate glasses was performed. The waste feed compositions used were obtained from current tank waste composition estimates, Hanford's baseline retrieval sequence, and pretreatment processes. The waste feeds were sorted into groups of like composition by cluster analysis. Glass composition optimization was performed on each cluster to meet property and composition constraints while maximizing waste loading. Glass properties were estimated using property models developed for Hanford HLW glasses. The impacts of many constraints on the volume of HLW glass to be produced at Hanford were evaluated. The liquidus temperature, melting temperature, chromium concentration, formation of multiple phases on cooling, and product consistency test response requirements for the glass were varied one- or many-at-a-time and the resultant glass volume was calculated. This study shows clearly that the allowance of crystalline phases in the glass melter can significantly decrease the volume of HLW glass to be produced at Hanford.
Thecal shunt placement for treatment of obstructive primary syringomyelia

Object The most commonly reported treatment of primary syringomyelia has been laminectomy with duraplasty or direct shunting from the syrinx cavity. Diversion of cerebrospinal fluid (CSF) from the spinal subarachnoid space to peritoneal, atrial, or pleural cavities has been described previously in only a few case reports. Shunting of the CSF from the subarachnoid space rostral to the level of myelographic blockage may reduce the filling force of the syrinx cavity and avoids myelotomy and manipulation of the spinal cord parenchyma. The authors report on 7 patients who underwent thecal shunt placement for primary spinal syringomyelia. Methods This study is a retrospective review of a consecutive series. The authors reviewed the medical records and neuroimaging studies of 7 adult patients with posttraumatic, postsurgical, or postinflammatory syringomyelia treated with thecoperitoneal, thecopleural, or thecoatrial shunt placement at the University of California Los Angeles Medical Center. Myelographic evidenc...
Compendious Genres: Higden, Trevisa, and the Medieval Encyclopedia

AbstractMedieval compendia, the Wikipedia of the Middle Ages, are a rich and productive source for medieval thinking about genre. For some medieval writers, writing in Latin or in the vernacular, compendiousness was not only an indicator of genre but also a pretext for genre thinking. It is at once a characteristic of a medieval genre and the means through which medieval writers experimented with genre. In this essay I focus on two compendious writers, the well-known Latin historian Ranulph Higden (died c. 1364) and his prolific English translator John Trevisa (d. 1402), both of whom saw the potential of compendia to shape genre. Higden used compendiousness to define a universal chronicle and to distinguish history from other large genres. For Trevisa, who translated Bartholomaeus Anglicus’s popular natural encyclopedia, De proprietatibus rerum, as well as the Polychronicon, compendiousness was a means of communicating with lay readers and of fashioning a supple and sensual vernacular. For both authors, b...
Do Short Sellers Cause the Weekend Effect

We claim that speculative short sellers are partly responsible for the weekend effect. Concerned with their inability to trade over the weekend and in an attempt to reduce their risk exposure, short sellers close their speculative positions on Fridays and re-establish new short positions on Mondays, causing higher returns on Friday than on Monday. We find evidence consistent with this claim. Stocks with higher short interest exhibit greater weekend effect than stocks with lower short interest. Examination of the weekend effect for IPOs, short-interest stocks, and highly volatile stocks lend additional support for our hypothesis. Although it is difficult for investors to directly trade individual stocks to profit from the weekend effect, they can protect themselves against the weekend effect by not selling stocks on Mondays and not buying on Fridays.
The Molecular Structure of Cyclopropene as Determined by Electron Diffraction

The molecular structure of cyclopropene has been determined by gas-phase electron difraction. A least-squares analysis was applied to the experimental molecular intensity to obtain the following geometric structural parameters: Cl-C3=1.304±0.003A, C3-C3=1.519±0.002A, C1-H=1.077±0.012A, C3-H=1.112±0.015A.
Three-dimensional wave propagation in composite cylindrical shells

An exact solution of free harmonic wave propagation in a composite laminated cylindrical shell is presented within the framework of the theory of three-dimensional cylindrically anisotropic elasticity. The dispersion equation governing these motions is established through a helical solution form in conjunction with a Frobenius power series method. Degenerate cases of infinite wavelength, axisymmetric waves, and of orthotropic shells are derived and discussed. Analytical results are presented for a variety of cases and are compared with those obtained from a Flugge shell theory.
Perceptual analyses of stuttering and nonstuttering children's fluent speech productions☆

Abstract Several investigators have reported a significant perceptual difference between adult stutterers' and nonstutterers' fluent speech productions. However, there is only limited information concerning the perceptual evaluation of stuttering and nonstuttering children's fluent speech. Therefore, in this study identical fluent sentences from nine stuttering children (mean age = 6 yrs, 8 mos) and nine nonstuttering children matched individually for sex and age (within 6 mos) were analyzed perceptually in both a paired- and single-stimulus paradigm by 12 sophisticated listeners. Individual subject analyses revealed that only one-half or fewer of the stutterers could be discerned in either paradigm. In the remaining cases, either no discrimination could be made or a nonstutterer was incorrectly identified as a stutterer. When averaged for subject group comparison, these findings indicated that listeners could not discriminate between the two groups. Possible explanations for this discrepancy in results between child and adult stutterers are proposed.
The validity of cervical dilation as an indication of true labor between 32 and 36 weeks 6 days of gestation

Objective Cervical dilation with regular contraction traditionally has been used to differentiate between true and false labor. This diagnostic criterion has not been tested as most patients receive tocolytics. Our objective was to determine the time from admission to delivery in women with preterm contractions and advanced cervical dilation without tocolytics. Study Design We reviewed the records of patients with preterm labor on the basis of regular contractions and cervical dilation ≥3 cm between 32 and 36 weeks 6 days of gestation. Chi-square analysis was performed for delivery at >1 week. Results In the records, 68.8% of the patients remained pregnant at >1 week without tocolysis. Between 32 and 34 weeks of gestation, the use of tocolysis did not help to prolong pregnancy >1 week (81% vs 88%; α = .05; power = 0.65). Conclusion Cervical dilation with preterm contraction cannot be used as an indication of true labor. More accurate methods to diagnose true preterm labor and direct management decisions are needed.
Effects of income variability on the demand for owner-occupied housing

Abstract This study investigates whether the uncertainty associated with an income stream affects the demand for owner-occupied housing. Theoretical models yield an ambiguous sign for the direction of change in consumption, but our empirical findings are consistent with the hypothesis that the consumption of housing falls when the uncertainty of receipt of income increases. Specifically, in a sample of military employees, the income earned by wives had little or no effect on the demand for housing. We also find evidence that suggests the demand for housing is affected by pension rights: the closer to retirement, the stronger the effect.
Kinetic Measurement of the Step Size of DNA Unwinding by Escherichia coli UvrD Helicase

The kinetic mechanism by which the DNA repair helicase UvrD of Escherichia coli unwinds duplex DNA was examined with the use of a series of oligodeoxynucleotides with duplex regions ranging from 10 to 40 base pairs. Single-turnover unwinding experiments showed distinct lag phases that increased with duplex length because partially unwound DNA intermediate states are highly populated during unwinding. Analysis of these kinetics indicates that UvrD unwinds duplex DNA in discrete steps, with an average “step size” of 4 to 5 base pairs (approximately one-half turn of the DNA helix). This suggests an unwinding mechanism in which alternating subunits of the dimeric helicase interact directly with duplex DNA.
On completeness and multi-channel sampling

A bandlimited input x is applied as a common input to m linear time-invariant filters (channels) which are ‘independent’ in a certain sense. We investigate, from a unified point of view using the concept of completeness, the problem of uniquely reconstructing the input x for all time values from samples of the m outputs, each output being sampled at the uniform rate of σ/gqm samples/second, where σ is the positive frequency bandwidth of the input signal. For the lowpass input case and independent channels, perfect reconstruction is always possible; similarly for the case of a bandpass input and an even number of channels, recovery of the input can also be accomplished at a rate of σ/mπ samples/second. However, for an odd number m of channels and a bandpass input, it is shown that the rate σ/mπ samples/second at the outputs no longer suffices to determine the input uniquely unless 2ω0m/σ is an odd integer, a constraint on the relation between the center frequency of the band, ω0, and the bandwidth σ. To obtain a sampling theorem when the number of channels is odd and in the absence of such a positioning constraint, a higher sampling rate per channel must be employed. In those cases which permit a unique determination of the input from samples of the output channels, it is shown that a linear scheme involving m linear time-invariant post-filters can be used to effect the input reconstruction.
The Structure of Scholarly Communications within Academic Libraries

AbstractAcademic libraries often define their administrative structure according to services they offer, including research services, cataloging and metadata, and acquisitions. Scholarly communications is something of a moving target, though. How are scholarly communication positions defined, what duties do they often include, and how do they fit within the library's administrative structure? Some of the first positions devoted to scholarly communications required JD's and focused on author's rights, copyright, and fair use. Yet other positions recently advertised group scholarly communication librarians within digital scholarship units, which not only create and maintain institutional repositories, they may also publish electronic journals and/or offer services related to data curation. This article provides a brief review of the findings recently published in a SPEC Kit, which focuses on ARL Libraries. The main intention, though, is to provide a wider context of scholarly communication activities across...
Biochemically Responsive Smart Surface

A design of smart surfaces responsive to biochemical analytes is demonstrated in the example of mixed monolayers of biotin/fluorocarbon. The contact angle of aqueous solutions on such surfaces decreases upon streptavidin binding and can be used in detecting this protein. The specificity of the effect is confirmed by the lack of a contact angle change by streptavidin blocked with biotin and by bovine serum albumin.
Magnifying miniature displays with microlenslet arrays

Current technology trends are focused on miniaturizing displays, although for specific applications such as the use of head-mounted displays (HMD) this limits the advancements for a wider field-of-view (FOV) and a negligible overall weight of the optics. Due to the advancements of electronics that benefit from smaller miniature displays, universities and companies are focused on developing this technology to meet the growing demand of this global market. Higher resolution displays with added brightness are being developed, but these displays are decreasing in their viewable area. HMDs can benefit from these higher resolution and brighter displays but they will undergo an increased optical weight to compensate for the smaller display size. To overcome this hindrance in HMDs, we demonstrate in this paper how to incorporate microlenslet arrays as an optical relay system to magnify miniature displays. Microlenslet arrays provide respectively shorter focal length which yields a smaller overall object to image distance and an incremental overall weight compared to an otherwise increased optical lens assembly. The contribution of this paper is a patented concept of magnifying/demagnifying miniature displays with microlenslet arrays that can be integrated in a spaced limited area.
Developmental changes in the use of categorization as a study strategy

Kindergarten, third-grade, fifth-grade, and college subjects were asked to memorize a single set of randomly arrayed items containing readily identifiable categories. The items were available during four trials, each trial consisting of a 30-sec study period followed by a free recall test. Preceding the last three trials, each subject was allowed to select one-third of the to-be-remembered items for study but was asked to attempt recall of all the items. The strategy of selecting items from the same category for study was rarely used spontaneously by kindergartners but was used by the older subjects. Efficiency comparisons suggested that this strategy would prove useful to kindergartners if used by them.
A network simulation model for police patrol vehicle maintenance and replacement analysis

Abstract Research in the field of urban police patrol-car analysis has tended to concentrate in the areas of vehicle deployment, fleetsize and location, etc., with very little emphasis in the area of vehicle maintenance and replacement policy. As such, the purpose of this paper is to develop and demonstrate a simulation model for patrol-vehicle replacement and maintenance analysis. The simulation model will encompass a Markov-type framework of state movements where the states represent the various stages of a patrol vehicle's life from new to inoperable. The model will be developed in the form of a Q-Gert network, and, demonstrated via a case example of an urban patrol fleet of 100 vehicles.
Approaches for service deployment

Traditional IT service-deployment technologies are based on scripts and configuration files, but their limited ability to express dependencies and verify configurations results in hard-to-use and erroneous system configurations. Emerging language- and model-based tools promise to address these deployment challenges, but their benefits aren't yet clearly established. The authors compare manual, script-, language-, and model-based deployment solutions in terms of scale, complexity, expressiveness, and barriers to first use.
Approaches to the synthesis of retro‐inverso peptides

Partial retro-inverso modification of biologically active peptides is described as a topochemical alteration of the backbone to prevent enzymatic degradation. The preparation of gem-diaminoalkyl residues from peptide amides using the reagent [bis(trifluoroacetoxy)iodo] benzene (TIB) is discussed. Treatment of N-t-butyloxycarbonyl tyrosine and N-t-butyloxycarbonyl tryptophan with this reagent led to decomposition of the protected amino acids. Protecting the tyrosine and tryptophan residues by t-butyl ether and Nin-formyl groups, respectively, prevented decomposition and led to good yields of the desired products. Racemic 2-alkylmalonyl diastereomers were found to be separable by HPLC. The chiral stability of peptides containing optically active malonyl residues was investigated under simulated physiological conditions. Synthetic considerations for the incorporation of gem-diaminoalkyl and 2-alkylmalonyl residues into larger peptides to yield partially modified retro-inverso peptide analogs are presented.
P3 systems: putting the place back into social networks

The availability of technologies enables a new class of location-aware information systems that link people-to-people-to-geographical-places (P3 systems). P3 systems can strengthen the relationship between social networks and physical places. They can also help individuals leverage location information to make new social ties and coordinate interactions that reinforce existing ties. Using the P3 systems framework, we describe the design space for location-aware community systems and important socio-technical challenges and opportunities.
A Fast System-Level Design Methodology for Heterogeneous Multi-Core Processors Using Emerging Technologies

A fast and efficient system-level design methodology is developed and validated to evaluate and optimize processors using emerging technologies at the early design stage. It includes an updated empirical cycle per instruction model, a hierarchical memory model, and several multi-level interconnection network models. Multiple device- and system-level design parameters are simultaneously optimized to maximize the chip throughput for a given device technology and an architecture family under certain power, thermal and die size budgets. In the single-core processor analysis, a high-performance (HP) 25 mm $^{2}$ FinFET processor can provide 26% more throughput than its planar HP complementary metal–oxide–semiconductor (CMOS) counterpart, and a low-power (LP) tunnel field-effect transistor (TFET) processor can offer more than 2X improvement in throughput compared with its LP FinFET counterpart at the 16 nm technology node. For various technology nodes, an accurate power-law relation is observed between the throughput and the die size area for a relatively small processor. In the multi-core processor analyses, multiple device- and system-level design parameters are obtained for both HP and LP applications with symmetric and asymmetric configurations. For a heterogeneous CMOS-TFET multi-core processor, about 45% throughput improvement and 50% energy reduction are observed compared with a FinFET processor at a 5 W power budget.
Current Issues in the Cross-Cultural and Cross-National Consumer Research in the New Millennium

Abstract An expanded model of the effect of culture on consumer behavior is presented in this paper. This model expands upon the model earlier developed by the authors, specifically incorporating two significant issues relevant for cross-cultural and cross-national consumer research in the new millennium. These include: (1) consumer motivation reflecting materialism and status seeking and impression building as the salient forces and (2) intense competition in the marketplace. The other four papers included in this special issue are mapped on to this model and summarized in terms of the nature of the paper, cultures or/and nations compared and samples, cultural component/consequence, constructs and consumer behavior domain. Directions for future research are discussed.
Optical Network Security: Countermeasures in View of Attacks

The huge amount of traffic transportable by the next generation optical network is vulnerable to attacks, as is discerned from an alarmingly increase of incidents. The types of attack are expected to range from the typical eavesdropping and service denial to more sophisticated source mimicking. As a consequence, modern encrypted methods refuge to highly sophisticated methods that emanate from quantum mechanics, known as quantum cryptography. However, the sophistication and elegance of quantum-cryptography makes the assumption that the transmission medium and the components involved on the link are perfect and that the properties of photons and the signal intensity do not change during propagation over many kilometers. Therefore, a practical implementation of Q-C may exhibit its own vulnerabilities due to non-linear interactions between photons and medium. Therefore, in addition to the sophistication of QKD and encryption algorithms, an additional function is needed that detects malicious intervention on the transmission link as well as a countermeasure strategy that outsmarts the attacker. In this paper, we consider a practical optical signal that consists of multiple photons, we consider a pragmatic medium with nonlinearities, scattering and absorption centers. We describe a case of service denial with Q-C, a method by which an attack is detected, and we develop a countermeasure strategy outsmarting the attacker. Our method assumes that the data channel is encrypted using sophisticated algorithms.
The Development of a Campus-Based Substance Abuse Prevention Program.

The development of a campus-based Substance Abuse Prevention Program (SAPP) is discussed. The program has been designed in accordance with recommendations made by prominent authorities in this field, keeping in mind the needs of the campus at which the program is located. Suggestions for developing such programs are provided.
COHERENT STATES IN THE THEORY OF SUPERFLUIDITY.

It is shown that the coherent-state representation of a many-boson wave function may be identified with the order-parameter function conventionally used to describe a superfluid. The statistical mechanics of the many-boson system is reformulated in terms of the coherent states, and a theory of the Ginzburg-Landau form is recovered in an obvious approximation. The formalism is particularly useful for describing metastable states of finite superflow and the fluctuations which may cause spontaneous decay of such states.
Rheological properties of LDPE processed by conventional processing machines

The impact of applied processing history and the postprocessing annealing on the rheological properties of low-density polyethylene (LDPE) have been studied employing various kinds of conventional processing machines. Processing by a corotating twin-screw extruder (Co-TSE) and an internal batch mixer depressed the drawdown force, one of the elastic properties of a melt, to a great extent, even though molecular weight and the polydispersity did not change. On the other hand, the sample processed by a two-roll mill exhibited the drawdown force as high as the original pellets, which is owing to the intermittent stress history instead of the relentless one in the Co-TSE and the internal batch mixer. Furthermore, the effect of screw configuration in the Co-TSE has also been investigated. It was found that the processing by conveying screws depressed the drawdown force and melt fracture more than that by kneading blocks as long as the torque and the residence time are the same. The large, abrupt, and frequent change in flow direction in the Co-TSE with kneading blocks prohibits the molecular orientation, which leads to disentanglement associated with long-chain branches. © 2003 Wiley Periodicals, Inc. Adv Polym Techn 22: 179–187, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10047
Low-temperature structural determination of anhydrous Li2SeO4

Abstract Anhydrous Li2SeO4 crystallizes in the trigonal space group R 3 with a = 13.931(2), c = 9.304(3) A, V = 1563.7 A3, Z = 18, Dc = 2.988 g cm−3. The unit cell transforms to the rhombohedral coordinate system as a = 8.620 A, α = 107.81(2)°, V = 521.2 A3, Z = 6. The structure contains selenate anions bridged by Li in the phenacite structural type. Data collection was performed at low temperature for precise placement of the Li cations which are tetrahedrally surrounded by oxygen atoms. Some problems with secondary extinction were apparent and a correction was made. The structure refined to an R value of 0.034.
Computing distances between partial rankings

We give two efficient algorithms for computing distances between partial rankings (i.e. rankings with ties). Given two partial rankings over n elements, and with b and c equivalence classes, respectively, our first algorithm runs in O(nlogn/loglogn) time, and the second in O(nlogmin{b,c}) time.
Block by phencyclidine of acetylcholine and barium induced adrenal catecholamine secretion.

Abstract Activation of the sympathetic system by phencyclidine (PCP) should result in catecholamine release from the adrenals. However, adrenalectomy does not reduce PCP-induced hypertension. In an attempt to rectify this inconsistency, the direct effects of PCP on the bovine adrenal medulla were examined. At (3×10 −6 M), PCP reduced the acetylcholine-(ACh)-induced catecholamine release by 50%. Surprisingly, barium-induced secretion of catecholamines was also reduced by PCP. ACh-induced catecholamine release was not altered by 10 −3 M 4-aminopyridine (4 AP), the potassium channel blocker. Thus, calcium antagonist actions of PCP and consequent block of catecholamine secretion from adrenal medulla may explain the lack of effect of adrenalectomy on PCP-induced hypertension. Possible contributions of calcium and/or potassium channel blockade to other manifestations of PCP overdosage are discussed.
Preferential adsorption of lower-charge glutamate ions on layered double hydroxides: An NMR investigation

13C MAS NMR spectroscopy of isotopically enriched samples of the layered double hydroxide hydrotalcite (HT) [(Mg2Al)(OH)6A−,nH2O, where A− is a counteranion that may bear different charges] exchanged with glutamate (Glu) shows an unexpected preferential adsorption of the lower-charged species (Glu1−) relative to the higher-charged species (Glu2−) by a layered double hydroxide (LDH) compound. At pH 11.0, the Glu1−/Glu2− ratio is about 0.44, an order of magnitude greater than expected in solution. Previous studies of phosphate and carbonate exchange onto LDH compounds (refs 25 and 26) show a strong preference for the higher-charged anion. The preference for Glu1−, in which the amine site is protonated, may be due in part to −NH3+ allowing for an energetically more favorable H-bonding network among the anions, the metal hydroxide substrate, and the interlayer and surface water molecules compared to −NH2. Changes in the pH and the pKa of Glu near the HT surface and due to nanoconfinement may also play importa...
Unexpected Frontiers of Black Internationalism: African Americans in Soviet Central Asia, 1930–1976

Central Asia has long captured the imagination of Western travelers as an exotic and mysterious destination. After the region was incorporated into the Soviet Union, it became a centerpiece of the Soviet modernization campaign. African Americans in particular were greatly interested in Soviet Central Asia and what they perceived as an alternative to Western imperialism and American racial segregation. This article explores how Soviet Central Asia appeared to African Americans who traveled, worked, and lived in the region in the 1930s and compares these impressions with those of African American tourists who visited the region three decades later. Did African American engagement with Central Asia act as an emancipatory, creative force for interracial solidarity or did it constitute another form of Orientalist discourse?
A Structural Model of Shape

Shape description and recognition is an important and interesting problem in scene analysis. Our approach to shape description is a formal model of a shape consisting of a set of primitives, their properties, and their interrelationships. The primitives are the simple parts and intrusions of the shape which can be derived through the graph-theoretic clustering procedure described in [31]. The interrelationships are two ternary relations on the primitives: the intrusion relation which relates two simple parts that join to the intrusion they surround and the protrusion relation which relates two intrusions to the protrusion between them. Using this model, a shape matching procedure that uses a tree search with look-ahead to find mappings from a prototype shape to a candidate shape has been developed. An experimental Snobol4 implementation has been used to test the program on hand-printed character data with favorable results.
Protection by 5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione (oltipraz) against the hepatotoxicity of aflatoxin B1 in the rat

A new chemoprotective agent, oltipraz, was evaluated for alleviation of aflatoxin B1-induced hepatotoxicity. Male F344 rats were fed a diet supplemented with 0.075% oltipraz and compared to rats fed the purified diet (AIN) alone. Rats were fed these diets for 1 week prior to treatment with aflatoxin B1 (AFB1) and throughout the experimental period. AFB1 was administered to rats by gavage in single doses ranging from 0.25 to 10 mg/kg body weight for acute toxicity studies and in multiple doses of 0.25 mg/kg, 5 days/week, for 2 weeks for subchronic toxicity studies. The latter protocol constitutes a tumorigenic dosing regimen. In an acute toxicity study, pretreatment with oltipraz reduced from 83 to 36% the mortality produced by 10 mg/kg AFB1. Oltipraz significantly suppressed the elevated serum levels of alanine amino transaminase and sorbitol dehydrogenase induced by sublethal doses of AFB1. In subchronic toxicity studies, the AFB1-treated rats fed AIN diet failed to gain weight over the 2-week treatment period and their liver weights were severely depressed. In contrast, the rats fed the oltipraz supplemented diet maintained a high rate of growth during AFB1 treatment. The subchronic AFB1 treatment regimen also resulted in over 75% loss of prelabeled [3H]thymidine from the liver while oltipraz supplementation largely prevented this loss. Taken together, these results indicate that oltipraz is very effective in ameliorating the toxic effects of AFB1 in rats.
Effects of Ozone, Sulfur Dioxide, Soil Water Deficit, and Cultivar on Yields of Soybean

The effects of ozone (O₃) stress on bean yields and seed size of four soybean cultivars [Glycine max (L.) Merr.] grown in open-top chambers in 1981, 1982, and 1983 are presented. The O₃ treatments included charcoal filtered (CF) and nonfiltered (NF) air, and 0.03, 0.06, and 0.09 µL L⁻¹ O₃ added 7 h d⁻¹ to NF air. The effects of SO₂ in concentrations from 0.005 to 0.224 µL L⁻¹ (4 h d⁻¹, 5 d wk⁻¹) from the seedling stage to maturity were studied in 1981 and 1982. In 1982 and 1983 the effects of soil moisture stress (SMS) and well-watered (WW) soil conditions on the response of soybean to O₃ stress were determined. The primary objective was the evaluation of 3 yr of soybean data from our site using the nonlinear Weibull and the polynomial dose-response models to relate yield responses to O₃ exposure doses. The variables also included SO₂, soil moisture, and cultivar. The homogeneity of the response equations were compared to permit development of the smallest set of homogeneous equations over years. Both O₃ and SO₂ negatively impacted bean yields and seed size. No interactions between O₃ and SO₂ were indicated. With the Weibull model, interactions between O₃ and soil moisture were observed with ‘Forrest’ in 1982 and ‘Williams’ in 1983. With an O₃ level considered typical in soybean production areas (seasonal 7 h d⁻¹, 0.055 µL L⁻¹) compared to background O₃ (0.025 µL L⁻¹) and using all data from 3 yr of experiments, the Weibull model predicted the same (15%) mean yield loss under both SMS and WW regimes. Research partly supported by interagency agreement between USEPA and the USDA, no. 12-14-7001-1282.
Executive Evaluation of College Student Learning via Tie Looking Glass, Inc. Simulation

This study measures the effects of involving beginning management students in an organizational simulation, 771E LOOKING GLASS, INC. A control and experimental group of students were compared in a pre- and posttest design. They responded to the question, What does a manager in a mid to large organization do on a daily basis?" Executives of mid- to large-sized organizations et the student responses Analysis indicated significant gains in knowledge for the students who participated in the simulation.
The Mechanical Structure of a New Energy-Saving Pumping Unit Analysis by Pro/E

Traditional oil drilling equipment cannot meet the demand of oilfield drilling technology in the later period. Application of new technologies, energy saving and cost reduction are development directions of the oil pumping machine. This paper introduces a new energy-saving hydraulic pumping unit with hydraulic energy recovery system, which drives the hydraulic cylinder to finish pumping action that can reduce the equipment power by 40% under the same load. In this paper, the mechanical structure of a new type of oil pumping unit is built and analysis is done by Pro/E software. The analysis results show: The guiding vehicle mechanism itself contributes to counterweight, and hydraulic actuator is directly connected to the base. So it has the advantages of a simple structure, saves steel, light weight, smaller in size and the manufacturing process requirements are not high. This shows that the machine can directly replace the traditional conventional beam pumping unit and has higher application value.
Nanostructural, electrical, and tribological properties of composite Au–MoS2 coatings

Abstract Considerable research has been done on the tribological properties of cosputtered metal/MoS2 solid lubricant films with low metal content (
Structural Analysis of the αN-Terminal Region of Erythroid and Nonerythroid Spectrins by Small-Angle X-ray Scattering†

We used SpalphaI-1-156 peptide, a well-characterized model peptide of the alphaN-terminal region of erythrocyte spectrin, and SpalphaII-1-149, an alphaII brain spectrin model peptide similar in sequence to SpalphaI-1-156, to study their association affinities with a betaI-spectrin peptide, SpbetaI-1898-2083, by isothermal titration calorimetry. We also determined their conformational flexibilities in solution by small-angle X-ray scattering (SAXS) methods. These two peptides exhibit sequence homology and could be expected to exhibit similar association affinities with beta-spectrin. However, our studies show that the affinity of SpalphaII-1-149 with SpbetaI-1898-2083 is much higher than that of SpalphaI-1-156. Our SAXS findings also indicate a significantly more extended conformation for SpalphaII-1-149 than for SpalphaI-1-156. The radius of gyration values obtained by two different analyses of SAXS data and by molecular modeling all show a value of about 25 A for SpalphaI-1-156 and of about 30 A for SpalphaII-1-149, despite the fact that SpalphaI-1-156 has seven amino acid residues more than SpalphaII-1-149. For SpalphaI-1-156, the SAXS results are consistent with a flexible junction between helix C' and the triple helical bundle that allows multiple orientations between these two structural elements, in good agreement with our published NMR analysis. The SAXS findings for SpalphaII-1-149 support the hypothesis that this junction region is rigid (and probably helical) for alphaII brain spectrin. The nature of the junction region, from one extreme as a random coil (conformationally mobile) segment in alphaI to another extreme as a rigid segment in alphaII, determines the orientation of helix C' relative to the first structural domain. We suggest that this particular junction region in alpha-spectrin plays a major role in modulating its association affinity with beta-spectrins, and thus regulates spectrin tetramer levels. We also note that these are the first conformational studies of brain spectrin.
Transition operators in electromagnetic-wave diffraction theory: General theory.

A formal theory is developed for the scattering of time-harmonic electromagnetic waves from impenetrable immobile obstacles with given linear, homogeneous, and generally nonlocal boundary conditions of Leontovich (impedance) type for the wave of the obstacle's surface. The theory is modeled on the complete Green's function and the transition (T) operator in time-independent formal scattering theory of nonrelativistic quantum mechanics. An expression for the differential scattering cross section for plane electromagnetic waves is derived in terms of certain matrix elements of the T operator for the obstacle.
Searching the Web: New Tools—New Dilemmas

Abstract Drawing on their experiences as researchers and teacher educators, the authors discuss issues concerning student research that uses web-based references. This article describes ways the authors: 1) structure the inquiry process for student research, 2) help students manage the quantity of information, and 3) provide a model for analyzing the quality of information that students find on web sites. The web-site analysis form provided to students requires them to evaluate information provided about the “who, what, when, how, and where” of a web site. The authors conclude with a discussion of the ways this model helps students engage, organize, and publish information in ways that share the knowledge that the students have constructed and the process of their inquiry.
Electrochemical properties of hypo-stoichiometric Y-doped AB2 metal hydride alloys at ultra-low temperature

Abstract The structure, gaseous phase, and electrochemical hydrogen storage properties of two series of Y-doped AB 2 metal hydride alloys were compared. While the stoichiometry (B/A ratio) of the average alloy composition of the first series is maintained at 1.99 (Ti 12 Zr 21.5 V 10 Cr 7.5 Mn 8.1 Co 8.0− x Ni 32.2 Y x Sn 0.3 Al 0.4 ), those in the second series decrease from 1.99 to 1.83 ((TiZr)(VCrMnNiSnAl) 1.75 Co 0.24−3 x Y x ). Since the solubility of Y in the main phase (C14) is limited (0.1–0.2 at.%), the influences of Y are through the changes in the composition and abundance of the main and secondary phases. While TiNi phase is considered beneficial to activation, surface reaction area, and surface charge-transfer, YNi phase is on the contrary. By adjusting the stoichiometry, we were able to increase the TiNi-to-YNi ratio and lower the −40 °C charge-transfer resistance by increasing the surface reaction area while maintaining the same surface catalytic ability. The lowest −40 °C charge-transfer resistance was obtained through an AB 2 alloy with 0.4 at.% Y and a B/A ratio of 1.93. Further improvement in the ultra-low temperature performance of the AB 1.93 alloy is expected by combining the current result with other modifiers, such as Si, to improve the surface catalytic ability.
Gliotoxin causes apoptosis and necrosis of rat Kupffer cells in vitro and in vivo in the absence of oxidative stress: exacerbation by caspase and serine protease inhibition.

Background/Aims A potential application of gliotoxin therapy for liver fibrosis was suggested by its apoptotic effect on fibrogenic activated stellate cells. We investigated if gliotoxin exerts similar effects on hepatic macrophage Kupffer cells. Methods Effects of gliotoxin on Kupffer cells isolated from the normal liver and in vivo following its administration to CCl 4 -induced cirrhotic rats were studied. Results Gliotoxin caused apoptosis of cultured Kupffer cells, the effect being apparent at 0.3μM concentration within 1h; longer incubation caused necrosis. This effect was associated with mitochondrial cytochrome c release, caspase-3 activation and ATP depletion. Interestingly, inhibition of caspase-3 and serine proteases accelerated and augmented gliotoxin-induced cell death via necrosis. Gliotoxin stimulated nuclear translocation of NFκB, and phosphorylation of p38, ERK1/2 and JNK MAP kinases, but these signaling molecules were not involved in gliotoxin-induced death of Kupffer cells. In vivo administration of gliotoxin to cirrhotic rats caused apoptosis of Kupffer cells, stellate cells and hepatocytes. In control rats, the effect was minimal on the nonparenchymal cells and not apparent on hepatocytes. Conclusions In the fibrotic liver, gliotoxin nonspecifically causes death of hepatic cell types. Modification of gliotoxin molecule may be necessary for selective targeting and elimination of activated stellate cells.
Prevention of neonatal group B streptococcal infection.

The highest annual death rate before the sixth decade of life occurs during the first year of life.1 Most deaths during the first year occur during the perinatal period, particularly between the on...
A novel role of IL-17-producing lymphocytes in mediating lytic bone disease in multiple myeloma.

Osteoclast (OC)–mediated lytic bone disease remains a cause of major morbidity in multiple myeloma. Here we demonstrate the critical role of interleukin-17–producing marrow infiltrating lymphocytes (MILs) in OC activation and development of bone lesions in myeloma patients. Unlike MILs from normal bone marrow, myeloma MILs possess few regulatory T cells (Tregs) and demonstrate an interleukin-17 phenotype that enhances OC activation. In univariate analyses of factors mediating bone destruction, levels of cytokines that selectively induce and maintain the Th17 phenotype tightly correlated with the extent of bone disease in myeloma. In contrast, MILs activated under conditions that skew toward a Th1 phenotype significantly reduced formation of mature OC. These findings demonstrate that interleukin-17 T cells are critical to the genesis of myeloma bone disease and that immunologic manipulations shifting MILs from a Th17 to a Th1 phenotype may profoundly diminish lytic bone lesions in multiple myeloma.
Seed yields and water use of cowpeas ( Vigna unguiculata [L.] walp.) subjected to planned-water-deficit irrigation

Cowpeas (Vigna unguiculata [L.] Walp.) were subjected to six irrigation treatments and two levels of soil nitrogen during two seasons under field conditions. Withholding irrigation during the vegetative stage in a rain-free environment following pre-irrigation resulted in lower water use (−11 to −20%) but negligible effects on seed yields (−2 to +3%) providing the irrigation interval during flowering and pod filling was not too great. Lengthening the irrigation interval resulted in less vine elongation and less shoot biomass production. Significant reductions in seed yield were observed only with the longest irrigation interval. The higher level of soil nitrogen resulted in small or negligible increases in shoot biomass production and seed yield.