cssi/SciSciGPT-SciSciNet huggingface dataset:
Low-temperature compaction of nanosize powders

Publisher Summary This chapter explores the various techniques of low-temperature compaction of nanosize powders. One of the more important challenges in the fabrication of nanostructured materials is how to achieve full densification of the powder while simultaneously retaining a nanoscale microstructure. High-pressure compaction of nanosize particles has been used in an attempt to achieve the desired nanoscale microstructure and high density in the green body. Typical compaction pressures usually exceed 1.0 GPa and, therefore, require specialized equipment. There are two different types of low-temperature high pressure powder compaction: diamond anvil pressure cell and high-pressure compaction with the piston-cylinder device. The longer sintering times and higher temperatures required promote excessive grain growth and/or irregular grain growth, resulting in a microstructure that does not exhibit the desired nanosize grain structure. The homogeneity and density of the green compact is critical in many situations, especially because the cold compaction density of most ceramic nanosize powders is extremely low. Obtaining a high green density is not the ultimate accomplishment in the processing of nanosize powders. The reason for this is that, in many cases, ceramic powders exist as metastable phases when they are prepared as very fine powders. These materials are metastable and may transform, typically involving significant volume changes, during high-temperature sintering.
Cloning of the Bacillus subtilis recE+ gene and functional expression of recE+ in B. subtilis.

By use of the Bacillus subtilis bacteriophage cloning vehicle Phi 105J23, B. subtilis chromosomal MboI fragments have been cloned that alleviate the pleiotropic effects of the recE4 mutation. The recombinant bacteriophages Phi 105Rec Phi1 (3.85-kilobase insert) and Phi 105Rec Phi4 (3.3-kilobase insert) both conferred on the recE4 strain YB1015 resistance to ethylmethane sulfonate, methylmethane sulfonate, mitomycin C, and UV irradiation comparable with the resistance observed in recE/sup +/ strains. While strain YB1015 (recE4) and its derivatives lysogenized with bacteriophage Phi105J23 were not transformed to prototrophy by B. subtilis chromosomal DNA, strain YB1015 lysogenized with either Phi 105Rec Phi 1 or Phi 105RecPhi 4 was susceptible to transformation with homologous B. subtilis chromosomal DNA. The heteroimmune prophages Phi 105 and SPO2 were essentially uninducible in strain YB1015. Significantly, both recombinant prophages Phi 105RecPhi 1 and Phi 105Rec Phi 4 were fully inducible and allowed the spontaneous and mitomycin C-dependent induction of a coresident SPO2 prophage in a recE4 host. The presence of the recombinant prophages also restored the ability of din genes to be induced in strains carrying the recE4 mutation. Finally, both recombinant bacteriophages elaborated a mitomycin C-inducible, 45-kilodalton protein that was immunoreactive with Escherichia coli recA/sup +/ gene productmore » antibodies. Collectively, these data demonstrate that the recE/sup +/ gene has been cloned and that this gene elaborates the 45-kilodalton protein that is involved in SOB induction and homologous recombination.« less
Normal and abnormal sleep in the elderly.

Publisher Summary This chapter reviews both normal and abnormal sleep in the elderly. Polysomnography (PSG) has provided objective evidence of the changes in sleep architecture that occur with aging. Compared with younger adults, the elderly spend more time in bed but have deterioration in both quality and quantity of sleep. These changes can lead to excessive daytime sleepiness (EDS), which in turn can lead to intentional and unintentional napping. Objective tests of daytime sleepiness performed in the elderly have shown that they are sleepier than younger adults, suggesting that the elderly are not able to obtain an adequate amount of sleep at night. Research has suggested that the elderly have a decreased ability to sleep thatis often reported as insomnia. There are three primary sleep disorders that are commonly found in the elderly: sleep-disordered breathing (SDB), restless-legs syndrome (RLS)/periodic limb movements in sleep (RLS/PLMS), and REM sleep behavior disorder (RBD). The diagnosis requires a good sleep history and at times a sleep study. Treatment should address the primary problem rather than the complaint and may result in significant improvement in the quality of life and daytime functioning in the elderly.
A Threshold Model for the Migration-Trade Link

How are immigration and trade related? The existing literature has found a positive effect of migration on trade, with migration working through both network and preference channels to increase international trade. I extend this analysis by examining this relationship across different levels of both migration and economic development. Migration from poor countries has a larger effect on trade than that from rich countries, reflecting the weaker trading institutions in poor countries that migrant networks may replace. For poor country migration, the marginal impact of migration is largest at high levels of migration. For rich country migration, this marginal effect declines as migration increases, suggesting that local production may be replacing native country exports. Sample splits are endogenized using Hansen's (2000) technique and greater support is found for a regime change across income levels. These results are relevant from both an academic and policy perspective as they suggest that the existing literature has underestimated the impact of poor country migration on trade, a key result when discussing migration policy.
Divide and Conquer Machine Learning for a Genomics Analogy Problem

Genomic strings are not of fixed length,but provide one- dimensional spatial data that do not divide for conquering by machine learning into manageable .xed size chunks obeying Dietterich independent and identically distributed assumption.We nonetheless need to divide genomic strings for conquering by machine learning in this case for genomic prediction. Orthologs are genomic strings derived from a common ancestor and having the same biological function.Ortholog detection is biologically interesting since it informs us about protein divergence through evolution, and,in the present context,also has important agricultural applications. In the present paper is indicated means to obtain an associated (fixed size)attribute vector for genomic string data and for dividing and conquering the machine learning problem of ortholog detection herein seen as an analogy problem.The attributes are based on both the typical string similarity measures of bioinformatics and on a large number of differential metrics,many new to bioinformatics.Many of the differential metrics are based on evolutionary considerations,both theoretical and empirically observed,in some cases observed by the authors. C5.0 with AdaBoosting activated was employed and the preliminary results reported herein re complete cDNA strings are very encouraging for eventually and usefully employing the techniques described for ortholog detection on the more readily available EST (incomplete)genomic data.
Constructing the criminal tribe in colonial India: acting like a thief, edited by Henry Schwarz

Henry Schwarz's book Constructing the Criminal Tribe in Colonial India: Acting Like a Thief is a new, nuanced and incisive account of the long history of the criminalization of particular native gr...
Demonstration of p-type In 0.7 Ga 0.3 As/GaAs 0.35 Sb 0.65 and n-type GaAs 0.4 Sb 0.6 /In 0.65 Ga 0.35 As complimentary Heterojunction Vertical Tunnel FETs for ultra-low power logic

Extremely scaled high-k gate dielectrics with high quality electrical interfaces with arsenide (As) and antimonide (Sb) channels are used to demonstrate complimentary ‘all III–V’ Heterojunction Vertical Tunnel FET (HVTFET) with record performance at |V DS |=0.5V. The p-type TFET (PTFET) has I ON =30µA/µm and I ON /I OFF =105, whereas the n-type TFET (NTFET) has I ON =275µA/µm and I ON /I OFF =3×105, respectively. NTFET shows 55mV/decade switching slope (SS) while PTFET shows 115mV/decade SS in pulsed mode measurement. Vertical TFET offers 77% higher effective drive strength than Si-FinFET for given inverter standard cell area. Energy-delay performance of TFET shows gain over CMOS for low V DD logic applications.
Filial piety of children as perceived by aging parents in China

Mao W, Chi I. Filial piety of children as perceived by aging parents in China Int J Soc Welfare 2011: 20: S99–S108 © 2011 The Author(s), International Journal of Social Welfare © 2011 Blackwell Publishing Ltd and the International Journal of Social Welfare. How aging parents perceive their children's filial piety has been shown to be an important indicator of older adults' well-being. The few studies that have discussed factors associated with perceived filial piety from the viewpoints of older adults in the Chinese context are limited in terms of the number of factors considered and the representativeness of samples. This study examined potential correlates of perceived filial piety of children among older adults in China. It was based on a subsample (n = 19,415) of adults aged 60 and older with children from the national representative study Sample Survey on Aged Population in Urban/Rural China in 2000. Results from logistic regression show that older adults who received financial and instrumental support from children perceived their family as harmonious, and those who coresided with a married son or married daughter were more likely to consider their children as pious.
On the equilibrium distribution of like-signed vortices in two dimensions

We study the equilibrium statistics for a system of point vortices of different circulations in two-dimensions. We use the methods of Lundgren and Pointin [2] who have analyzed this problem in the past for vortices of the same strength. This necessitates the development of the probability density functions for each of the vortices. We find a power-law relationship between the probability distributions of vortices with different circulations. These distributions are verified numerically.
Determination of 5-hydroxytryptamine metabolites in isolated perfused rabbit lung by high-performance liquid chromatography.

Abstract An analytical procedure, utilizing high-performance liquid chromatography (HPLC) hasbeen developed for the separation of radiolabeled metabolites of 5-hydroxytryptamine (5-HT) in biological fluids. Four different chromatographic systems are described, which enable the separation of groups of metabolites possessing similar organic functionality to be achieved. As an example of this general analytical method, it is demonstrated that no methylation of 5-HT occurs in perfused rabbit lung, the principal metabolites being 5-hydroxyindoleacetic acid and 5-hydroxytryptophol.
DNA synthesis and DNA enzymes in terminally differentiating cardiac muscle cells

Abstract Myocytes at various stages of terminal differentiation were isolated from ventricular cardiac muscle of the rat. These cells were observed to acquire the morphology of the adult, cease synthesizing DNA and lose the activity of several enzymes whose activities are needed to replicate DNA by the third week of postnatal development. After this period of development, acquisition of the contractile proteins increases and the cells enlarge substantially to accommodate the new contractile elements.
Improvement of humidity resistance of magnesium powder using dry particle coating

Abstract Dry particle coating is used to enhance the moisture resistance of ground magnesium powder (primary size 75 μm) by coating its surface with carnuba wax (primary size 15 μm). Coating was done using magnetically assisted impact coating (MAIC), and two high-speed impaction-coating devices, the hybridizer and mechanofusion. The uncoated and coated samples are characterized by scanning electron microscopy (SEM), humidity tests, and X-ray diffraction. SEM images indicate that in MAIC the coated wax is mainly observed in and around the cracks, whereas in the hybridizer and mechanofusion the wax was softened and spread more evenly over the magnesium surface. The results of 150-h humidity tests as well as extended 400-h tests show a significant improvement in the moisture resistance of ground magnesium powder after coating in all three devices. Extended 400-h tests show that in some cases, the wax-coated samples perform similar to atomized magnesium. In particular, the mechanofusion-coated product showed moisture resistance comparable to atomized magnesium, with an amount of wax as little as 2%. These results are also verified by XRD analysis to measure the amount of hydroxide formation. Thus the wax coating increases humidity resistance by delaying hydroxide formation, hence increasing the shelf life of the coated ground magnesium.
Conformational Studies and Structure−Activity Analysis of Lissoclinamide 7 and Related Cyclopeptide Alkaloids

The macrocyclic arrays of heterocycles and amides present in Lissoclinum peptides can serve as templates for selective metal ion binding and as lead structures for the design of conformationally preorganized peptides and peptidomimetics. The currently available secondary structure information for this class of marine alkaloids, however, is limited to 18- and 24-membered ring isomers. This work provides the first information on the solid state and solution conformation of the 21-membered class of Lissoclinum cyclopeptide alkaloids. The folding of lissoclinamide 7, both in the solid and in the solution state, is dominated by a combination of a type II β-turn formed at the prolyloxazoline moiety and a β-loop segment stabilized by intramolecular five-membered hydrogen bonds at the thiazoline−d-phenylalanine−thiazoline moiety. The resulting rigid backbone geometry controls the preferred stereochemistry at the stereogenic α-carbons, and the natural compound represents the thermodynamically most favorable stereo...
Variations of mean cold season temperature, precipitation and snow depths during the last 100 years in the former Soviet Union (FSU)

Abstract Variations of temperature, precipitation and snow depths during the last 50–100 years, up to 1984, are investigated for mean cold season values (November to April) for 110 locations in the Former Soviet Union (FSU). Following quality checking, statistical analyses are performed on the data. There is cold season warming after 1953 or after 1966 over almost all the FSU apart from eastern Siberia, but temperature variations significantly affect the mean snow depths only in some sensitive areas of the Caucasus, central Asia, and the western European territory. Mean snow depth time series reveal contrasting local trends. Higher precipitation and snow depths are measured in eastern European Russia from 50° to 65 °N and in some areas of western Siberia at the beginning of the twentieth century. Otherwise, precipitation variations have little influence on the mean cold season snow depths over much of the FSU after 1930. Some predominant periodicities are detected for mean cold season temperature, but not...
A discriminating monopolist model of natural gas markets over the period 1960–1966

Abstract This paper presents estimates of what a monopoly would set natural gas prices at in the inter- and intra-state markets of the United States over the period 1960–1966. The predictions are accurate but not perfect. This paper cannot conclusively prove that price setting in these markets was done in this manner, however, due to lack of assumptions on the supply side. The estimates are close enough to be interesting though, and a model of the supply side should be developed.
Fiber-optic-based biosensors utilizing long period grating (LPG) technology

A biosensor based on long period grating (LPG) technology has been used to demonstrate the detection of large molecules (proteins) and small molecules (pesticides). The LPG sensor is a spectral loss optical fiber based system that provides direct detection of large molecules, by using an antigen or antibody modified hydrogel, without the need for secondary amplification. The binding of the specific target results in a mass increase that produces a localized refractive index change around the LPG region and thus a spectral shift in the observed wavelength loss band. The magnitude of the observed shift can be correlated to target concentration. The HIV protein p24 was directly detected at 1 ng/mL with a specific signal that was 5 - 7 times that of the system noise. A direct and indirect competitive assay was demonstrated with the target atrazine. The sensitivity of the two competitive assay formats was in the range of 10 - 50 ng/mL. In all three-assay examples, the biosensor was regenerated by treatment with 50 mM HCl and reused. The LPG biosensor offers speed (results in less than five minutes), versatility, reuse, specificity and sensitivity.
Metformin blunts stress-induced hyperglycemia after thermal injury.

Background Hyperglycemia is associated with detriments in immune function and impaired wound healing. The purpose of this study was to assess the effect of metformin, an oral antihyperglycemic agent approved for patients with diabetes mellitus, on glucose metabolism in severely burned patients. Methods Metformin was given in a double-blind, placebo-controlled fashion to 10 patients, all with burns > 60% body surface area (age, 36 +/- 4 years; weight, 92 +/- 3 kg; mean +/- SEM). After 8 days of metformin or placebo, glucose kinetics were quantitated using isotopic dilution with 6,6-d glucose and indirect calorimetry. Measurements were made during fasting; during an intravenous glucose infusion (30 micromol/kg/min); and during a hyperinsulinemic (500 mIU/m2/h), euglycemic clamp (mean plasma glucose concentration, 6.5 +/- 0.3 mmol/L). Results During fasting, metformin-treated subjects had a significantly lower rate of endogenous glucose production (met. 9.6) and glucose oxidation than placebo control subjects. With the administration of intravenous glucose, metformin treatment significantly accelerated glucose clearance, thereby attenuating hyperglycemia. During hyperinsulinemia, glucose uptake was significantly greater in metformin-treated patients. Patients receiving metformin also had a significantly higher plasma concentration of insulin. Conclusion These findings suggest a potential clinical efficacy of metformin to reduce stress-induced hyperglycemia by increasing glucose clearance. This effect may be mediated by either a metformin-induced augmentation of insulin sensitivity or by increasing insulin availability.
Phonology, Naturalness and Universals

This paper briefly surveys several conceptions of naturalness in phonology, touching primarily on typological frequency and the notion of ‘phonetic motivation’. It is argued that typological frequency is not a reliable indicator of what is ‘phonetically motivated’ as relative frequency patterns are the outcomes of more complex interactions including non-phonetic factors. Phonetic motivations are diverse and include random variations, not only deterministic results, as is often desired. Models that view phonological patterns as emerging from complex interactions of a variety of natural factors are the most satisfying.
Purification and characterization of dihydrobenzophenanthridine oxidase from elicited Sanguinaria canadensis cell cultures

Upon treatment of Papaveracea cells with fungal elicitors, the biosynthesis of benzo[c]phenanthridine alkaloids is induced. Dihydrobenzophenanthridine oxidase, which catalyzes a later step in the biogenesis of these alkaloids, is one of the enzymes whose activity is elevated in the process. Here we report the 211-fold purification of the oxidase from elicited Sanguinaria canadensis by a combination of ammonium sulfate fractionation, DEAE-Sephadex, CM-Sephadex, Sephadex G-200, and either phenyl Superose or gel filtration chromatography. The purified enzyme utilized molecular oxygen to oxidize dihydrosanguinarine to sanguinarine with concomitant formation of hydrogen peroxide. A pH optimum of 7.0, Vmax of 27 nkat/mg protein, and apparent Km of 6.0 microM for dihydrosanguinarine were determined. Dihydrochelerythrine was also found to be a substrate for the purified enzyme, displaying an apparent Km of 10 microM. However, neither dihydronorsanguinarine nor the indole alkaloid ajmalicine was oxidized, indicating that the enzyme has some substrate specificity. Apparent molecular weight estimates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the most purified enzyme preparation obtained contained a major component of 77 kDa and two minor components between 59 and 67 kDa that can be associated with oxidase activity. Purified enzyme preparations possessed activity that was inhibited by sodium diethyldithiocarbamate, sodium azide, potassium cyanide, 1,4-DL-dithiothreitol, and mercaptoethanol.
Phase Change Memory and its intended applications

Phase Change Memory (PCM) has been one of the emerging memories for more than a decade. Fundamentals of PCM have been studied in great detail, challenges have been identified, and device structures have been proposed and demonstrated. With this large body of knowledge, it is time to examine probable applications for PCM.
Remote ligand substituent effects on the properties of oxo-Mo(V) centers with a single ene-1,2-dithiolate ligand

Abstract The oxomolybdenum mono-ene-1,2-dithiolate complex (Tp*)MoO(bdtCl2) (3) has been synthesized and characterized (Tp* is hydrotris(3,5-dimethyl-1-pyrazolyl)borate; bdtCl2 is 3,6-dichloro-1,2-benzenedithiolate). The X-ray structural data show that 3 crystallizes in the monoclinic space group, P21/c, where a=7.963 (3), b=26.272 (11), c=14.016 (6) A, β=105.352 (7). The (Tp*)MoO(bdtCl2) molecule exhibits a distorted pseudo-octahedral coordination geometry, with the Mo atom ligated by a terminal oxo atom, two sulfur donor atoms of the bdtCl2 ligand and three nitrogen atoms of the tridentate facially coordinated Tp* ligand. The coordination environment about the Mo atom is similar to that of (Tp*)MoO(bdt) (1) (bdt is 1,2-benzenedithiolate), but the fold angle between the MoS2 plane and S2C2 plane of the bdtCl2 ligand (θ=6.9°) is substantially smaller than the feature in 1 (θ=21.3°). The similar IR, EPR, and electronic absorption spectroscopic results for 1 and 3 indicate that the electron withdrawing nature of the chlorine substituents of 3 does not significantly perturb the electronic structure of the Mo(V) center. However, the solution redox potentials and the gas-phase ionization energies are sensitive to remote substituent effects.
Electrical Uniformity of Direct Silicon Bonded Wafer Interfaces

This paper describes a series of electrical measurements and sample modifications that enabled the electrical properties of hybrid-orientation direct silicon bonded wafer interfaces to be determined. It is shown that the carrier transport across this near-surface (110)Si/(100)Si boundary is dictated by the defects present at the bond interface. These interface states are believed to pin the Fermi-level, producing a conduction barrier with a thermal activation energy Ea = 0.56eV. The defect band has been identified by deep-level transient spectroscopy and associated with the defect states typically observed in plastically deformed silicon. The carrier transport behavior across the bonding interface, as well as the observed interface trap levels are therefore attributed to the dislocation network present at the bonding interface. The spatial uniformity of the interface properties have been evaluated by TEM, electron-beam induced current microscopy, photoconductive decay and conduction measurements.
Exploring the dimensions of place: a confirmatory factor analysis of data from three ecoregional sites

Themes of place, situatedness, and locale are increasingly prominent in environmental education literature and practice. Sense-of-place research, which considers how people connect with places and the influence of those connections on engagement with the environment, may have important implications for environmental education. Prior place studies have proposed that people’s place connections have various dimensions. This paper explores four place dimensions, analyzing data from a survey (n = 712) conducted in three ecoregional sites in which we investigated residents’ sense of place. We examine how our data fit a proposed typology of place dimensions – a four-dimension (biophysical, psychological, sociocultural, and political-economic) categorization based on previous conceptions of the dimensions of place. We use structural equation modeling to question whether a 4-factor conceptualization of the dimensions of sense of place is superior to plausible alternatives. In comparing the four-dimension model wit...
Are personality assessments valid in acute major depression

A number of recent studies indicate that identification of Axis II comorbidity in depressed patients may influence both the initial treatment plan and subsequent prognosis. Nevertheless, the validity of personality disorder diagnoses may be compromised by the effects of the patients' depression on historical recall, which distort presentation of their premorbid strengths and liabilities. These problems are illustrated in this study of 53 acutely depressed unipolar outpatients, with (N = 14) or without (N = 39) personality disorder diagnoses as defined by the Personality Disorder Examination (PDE). We found that: 1) pretreatment PDE diagnoses had no significant associations with any measure of demography, symptomatic status, illness course, or treatment response; and 2) pretreatment PDE diagnoses typically were not confirmed when patients were reassessed following effective treatment with cognitive behavior therapy. These findings provide strong empirical support for the wisdom of deferring definitive assessment of Axis II until an acute depressive disorder has been optimally treated.
Internal activity of moy zeolites in epoxidation of cyclohexene: evidence from shape-selective poisoning

Abstract Shape-selective poisoning has been used to demonstrate that the epoxidation of cyclohexene occurs at Mo ions which are located within the cavities of a type-Y zeolite. The epoxidation reaction is poisoned by tributylamine which is able to enter the intracrystalline voids, but not by triphenylamine, which is too large to enter. Both amines effectively inhibit the activity of a homogeneous Mo complex.
Solubilization and characterization of microsomal protein kinases from rat liver

Abstract 1. 1. The protein kinases of rat liver microsomes have been solubilized and fractionated into protein kinases A and B by DEAE-cellulose chromatography. Both enzymes require Mn2+ or Mg2+ for maximal activity. 2. 2. Protein kinase A is an integral membrane protein and phosphorylates endogenous microsomal proteins which are also believed to be integral membrane proteins. Kinase B is loosely associated with the membrane and can phosphorylate exogenous histones in addition to microsomal proteins. 3. 3. Other differences between these two protein kinases are: (a) Kinase B is stimulated by cAMP or cGMP but kinase A is not. (b) Kinase B is inhibited by imidazole but kinase A is not. (c) The optimal pH for activity of kinase A is pH 6.5 and of kinase B is pH 8.0. (d) With kinase A, the Km is 286 μM ATP which is about 10 times higher than with kinase B. 4. 4. Microsomal protein kinase A has been resolved further into kinases A1 and A2. The phosphoprotein products of some of the samples have been analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. 5. 5. Microsomal protein kinase B is similar to cytosol kinase II in many properties, and can be dissociated presumably into regulatory and catalytic subunits.
Chip-scale sonic communication using AlN transducers

On-chip wired interconnects presents a bottleneck for VLSI integrated circuits. An additional channel with which to communicate information would be beneficial to supplement traditional wired designs. Utilizing virtual, reconfigurable ultrasonic interconnects operating at high bit rate could open new vistas for computer architecture and low power computing. The first step to this goal has been demonstrated in this paper by using ultrasonic pulses to communicate between two aluminum nitride thin film transducers on a silicon wafer representative of a VLSI substrate. Direct output voltages on receive pixels were on the order of 40-60 μVpp for a drive voltage on transmit pixels of 0.5 Vpp at 900 MHz. An FEA model was used to verify the time-of-flight and signal amplitudes to demonstrate that the primary mechanism is bulk acoustic waves travelling through the silicon substrate.
Mediators of the Development and Prevention of Violent Behavior

The purpose of this investigation was to determine if the Aban Aya Youth Project, a culturally grounded intervention, produced differences in changes over time in core intervening variables (i.e., communal value orientation, empathy, violence avoidance efficacy beliefs) and whether these variables mediated intervention effects on the development of youth violent behavior. Fifth grade cohorts at 12 schools were randomly assigned to one of two intervention conditions or an attention placebo control condition and followed longitudinally through eighth grade. A total of 668 students (49% male) participated in the study. Mediation analyses suggested that both program conditions (as compared to the control condition) led to steeper increases over time in empathy which, in turn were related to reductions in the likelihood of violent behavior over time. No other significant program effects were detected, although changes over time in violence avoidance efficacy were associated with reduced likelihood of violent behavior. Findings are discussed in terms of theory development, program development and points of refinement of the Aban Aya Youth Project and implications for future research.
Biological function of pancreatic ribonuclease.

The physiological function of this much studied pancreatic enzyme has been misunderstood. It is essential only in ruminants and certain other herbivores, where it has a special function.
Encoding and representation of simultaneous and sequential arrays in visuospatial working memory

The effect of presentation type on organization in visuospatial working memory (VSWM) was examined. Stimuli were presented sequentially or simultaneously at study, and participants made same/different judgements at test. The test array varied in four different spatial configuration conditions: one featuring no changes from study, one in which two items switched, one in which the same array repeated but in a different location, and one in which a completely novel test stimulus appeared. Results indicated the use of a global configuration for both simultaneous and sequential presentations and showed increased impairment of item-level knowledge with sequential presentations. Overall, these results support the use of a global configuration organization as a fundamental aspect of VSWM processing.
Role of Conserved Tyrosine 343 in Intramolecular Electron Transfer in Human Sulfite Oxidase

Tyrosine 343 in human sulfite oxidase (SO) is conserved in all SOs sequenced to date. Intramolecular electron transfer (IET) rates between reduced heme (Fe(II)) and oxidized molybdenum (Mo(VI)) in the recombinant wild-type and Y343F human SO were measured for the first time by flash photolysis. The IET rate in wild-type human SO at pH 7.4 is about 37% of that in chicken SO with a similar decrease in k(cat). Steady-state kinetic analysis of the Y343F mutant showed an increase in K(m)(sulfite) and a decrease in k(cat) resulting in a 23-fold attenuation in the specificity constant k(cat)/K(m)(sulfite) at the optimum pH value of 8.25. This indicates that Tyr-343 is involved in the binding of the substrate and catalysis within the molybdenum active site. Furthermore, the IET rate constant in the mutant at pH 6.0 is only about one-tenth that of the wild-type enzyme, suggesting that the OH group of Tyr-343 is vital for efficient IET in SO. The pH dependences of IET rate constants in the wild-type and mutant SO are consistent with the previously proposed coupled electron-proton transfer mechanism.
Nikon electron beam projection lithography tool development summary

In the development of the electron beam projection lithography (EPL) tool, one of the most important tasks is to develop the high-speed vacuum stage system and reliable vacuum body system. Nikon has a long history of over 22 years in precision stage development for its optical lithography tools as well as over 10 years in electron beam (EB) instrument development such as EB 60 with NTT. Recently, lithography stages have been developed based on air bearing and linear motor technologies. It is desirable and of minimum risk to utilize those technologies for the EPL system in order to shorten total time period of development, but the requirements for the EB stage and body are much different from their optical counterparts and much more difficult. In this paper, development and implementation of the EPL vacuum stage system, vacuum body system, vacuum loader system, and control system are discussed and overviewed.
Cleavage of human fibroblast type I procollagen by mammalian collagenase: demonstration of amino- and carboxy-terminal extension peptides.

Abstract Human skin fibroblasts in monolayer culture synthesize and secrete precursor forms of collagen into the culture medium. The type I collagen precursor, the major precursor in the culture medium, was isolated on DEAE cellulose chromatography and subjected to mammalian collagenase cleavage. The amino terminal cleavage fragments had a higher molecular weight than α1A and α2A, but did not contain interchain disulfide bonds. The carboxy-terminal cleavage fragments formed high molecular weight aggregates which contained interchain disulfide bonds. These results indicate that human type I procollagen contains noncollagenous amino and carboxy-terminal extension peptides and that all of the interchain disulfide bonds are on the carboxy-terminal portion of the molecule.
Biophysical characterization of α-crystallin aggregates : validation of the micelle hypothesis

The size of α-crystallin aggregates, as well as the structural organization of each particle's subunits, is currently unknown, although a number of different laboratories have suggested both structures and average molecular weights (Thomson, J.A. and Augusteyn, R.C. (1984) Proc. Int. Soc. Eye Res. 3, 152). One hypothesis, compatible with literature reports and consistent with what is known of subunit primary structure and physiological function, is that α-crystallin exists in vivo as a naturally occurring protein micelle (Sen, A.C. and Chakrabarti, B. (1991) Biophysical J. 59, 108a). To test this hypothesis, experiments were performed on this protein to determine its behavior under increased hydrostatic pressure and the effect of its concentration on aquous surface tension. With increasing hydrostatic pressure, the turbidity of an α-crystallin solution increases exponentially to a plateau at about 6000–8000 psi; upon release of pressure, the samples slowly return to their original turbidity level. Other naturally aggregating proteins, such as skeletal muscle myosin, demonstrate a decrease in turbidity under the same conditions. The surface tension of α-crystallin in aqueous solution decreases to a plateau with increasing protein subunit concentration, with an inflection point over the range 0.18–0.25 mM; cholate and other amphiphiles exhibit similar behavior. In contrast, plots of surface tension over the equivalent concentration range for other protein aggregates in the same buffer more closely approximate the types of curve obtained with short chain aliphatic acids. These results indicate that α-crystallin behaves like the protein version of a micelle.
Food web structure provides biotic resistance against plankton invasion attempts

It is generally accepted that native communities provide resistance against invaders through biotic interactions. However, much remains uncertain about the types of ecological processes and community attributes that contribute to biotic resistance. We used experimental mesocosms to examine how zooplankton community structure, invertebrate predation, and nutrient supply jointly affected the establishment of the exotic Daphnia lumholtzi. We predicted that establishment would increase with declining biomass and diversity of native zooplankton communities and that an invertebrate predator (IP) would indirectly facilitate the establishment of D. lumholtzi due to its relatively long predator-deterring spines. Furthermore, we hypothesized that elevated nutrient supply would increase algal food availability and facilitate establishment. Only when the biomass and diversity of native zooplankton were significantly reduced, was D.␣lumholtzi able to successfully invade mesocosms. Although invertebrate predation and resource supply modified attributes of native zooplankton communities, they did not influence the establishment of D. lumholtzi. Overall, our␣results are consistent with observed population dynamics in invaded reservoirs where D.␣lumholtzi tends to be present only during the late summer, coinciding with historic mid-summer declines in native zooplankton populations. Lakes and reservoirs may be more susceptible to invasion not only by D. lumholtzi, but also by other planktonic species, in the late summer when native communities exhibit characteristics associated with lower levels of biotic resistance.
Using Related Samples in Assessing Conformance to Safety Goals: A Nuclear Reactor Safety Application

Quantifying safety goals is a key to the regulation of activities which are beneficial on the whole but entail some risks in being performed. Determining compliance with safety goals involves dealing with uncertainties. A recent article by Bier(I) describes some of the difficulties encountered using measures with uncertainty to determine compliance with safety goals for nuclear reactors. This paper uses a hierarchical Bayes approach to address two practical modeling problems in determining safety goal compliance under uncertainty: (1) allowing some modeling assumptions to be relaxed, and (2) allowing data from previous related samples to be included in the analysis. The two issues effect each other to the extent that relaxing some assumptions allows the use of a broader range of data. The usefulness of these changes and their impact on assessing safety compliance for nuclear reactors is shown.
Redistribution of cadmium to blood of rats

Abstract Cd (1 mg/kg iv) is rapidly removed from the blood. By 3 hr after injection the concentration of Cd had decreased almost two orders of magnitude to 46 ng/ml and remained relatively constant for 12 hr before increasing to 75 ng/ml by 60 hr. To determine the mechanism for the increase in blood Cd concentration with time, the distribution of Cd among the blood components was examined at 5 and 60 hr after administration. The concentration of Cd decreased during this time interval by 95% in the plasma, did not change in WBCs, and was increased approximately twofold in RBCs. The concentration of Cd in the ghosts and cytosol of the RBCs increased to the same degree. Examination of the binding of Cd to various RBC cytosolic proteins by Sephadex G-75 chromatography revealed that Cd was bound mainly to high-molecular-weight proteins at both 5 and 60 hr after Cd administration. At 60 hr, a second protein peak with bound Cd was observed which had a molecular weight similar to metallothionein but differed from it in other characteristics. These results suggest that redistribution of Cd to blood is due to the increase in concentration of Cd in the RBCs. This increase does not appear to be solely due to an increase in metal-binding proteins in the cytosol of RBCs.
Origins and Implications of Sex

Betzig, Laura. Despotism and Differential Reproduction. New York: Aldine, 1986. xi + 171 pp. including appendix, bibliography, and index. $24.95 cloth. Halvorsen, Harlyn O. and Alberto Monroy, eds. The Origin and Evolution of Sex. New York: Alan R. Liss, 1986. xi + 345 pp. including tables, photographs, chapter references, and index. $68.50 cloth. Margulis, Lynn and Dorion Sagan. The Origin of Sex. New Haven: Yale University Press, 1986. xiii + 258 pp. including photographs, figures, index, glossary. $35.00 cloth. Pickford, M. and B. Chiarelli, eds. Sexual Dimorphism in Living and Fossil Primates. Firenze: Il Sedicesimo, 1986. 215 pp. including chapter references and indexes. $33.00 paper.
Control and mechanics of parturition in the pig

Abstract Perinatal death of fetuses as a consequence of the birth process accounts for nearly 22% of all fully formed fetuses. Some of the losses may be reduced when births are supervised. Supervision can be done practically and most efficiently when births are scheduled. Progesterone in the maternal plasma must decline before parturition even though levels of other hormones such as estrogens, cortisol and relaxin may change in ways characteristic of normal parturition. Prostaglandin F 2α can cause a decline in progesterone with parturition following in about 29 hours. The position and number of fetuses in the uterus can influence the probability of perinatal death with fetuses in the ovarian end of the uterus and those born after a prolonged interval being most likely to die.
A revised picture of the Cu(II)-α-synuclein complex: the role of N-terminal acetylation.

α-Synuclein (αS) is an amyloidogenic intrinsically disordered protein implicated in Parkinson’s disease, for which copper-mediated pathways of neurodegeneration have been suggested. We have employed nuclear magnetic resonance, circular dichroism, electrospray ionization mass spectrometry, and thioflavin T fluorescence to characterize interactions of Cu2+ with the physiological acetylated form (Ac-αS). Significantly, N-terminal acetylation abolishes Cu2+ binding at the high-affinity M1-D2 site present in the nonacetylated protein and maintains Cu2+ interactions around H50/D121. Fibrillation enhancement observed at an equimolar Cu2+ stoichiometry with the nonacetylated model does not occur with Ac-αS. These findings open new avenues of investigation into Cu2+-mediated neurodegenerative pathology suggested in vivo.
The coagulation of dissolved239, 240Pu in estuaries as determined from a mixing experiment

A mixing experiment, using large volumes (100 l) of filtered (< 1 μm) freshwater and seawater end-members, was performed to simulate and investigate the chemical reactivity of239, 240Pu during estuarine mixing. An organic-rich freshwater with a relatively high concentration (0.8 dpm/100 l) of dissolved239, 240Pu was used as one end-member; Buzzards Bay seawater (dissolved239, 240Pu= 0.04dpm/100l) was the other. The results demonstrate that dissolved239, 240Pu in the freshwater undergoes extensive and rapid coagulation under simulated estuarine conditions. There is a strong correlation between the amount of coagulation of dissolved239, 240Pu, humic acids (HA), and Fe. The extent of coagulation of all three constituents increases with increasing salinity and the net extent of their removal is 53%, 57%, and 100% for Pu, HA, and Fe respectively. As has been documented for Fe in freshwater, dissolved239, 240Pu appears to be stabilized by naturally occurring humic substances to form negatively charged colloids which are then coagulated by seawater cations. The extrapolation of these experimental results to real estuaries will require additional research.
From Risk Factors to Structural Heart Disease: The Role of Inflammation

Elevated levels of circulating proinflammatory cytokines and adipokines have been repeatedly associated with increased risk for clinically manifest (Stage C) heart failure in large cohort studies. However, the role of low-grade, subclinical inflammatory activity in the transition from risk factors (Stage A heart failure) to structural heart disease (Stage B heart failure) is less well understood. Recent evidence suggests that chronic low-grade inflammatory activity is involved in most mechanisms underlying progression of structural heart disease, including ventricular remodeling after ischemic injury, response to pressure and volume overload, and myocardial fibrosis. Inflammation also contributes to progression of peripheral vascular changes.
Trp-21 is important in the processing and secretion of big endothelin-1.

Abstract To investigate the intracellular processing of endothelin-1 (ET-1), the synthesis and secretion of preproET-1 (PPET-1) was studied in transiently transfected COS-7 cells. Replacements at the highly conserved C-terminal region of ET-1 were made by site-directed mutagenesis, with codons for residues Ile-20 and Trp-21 being replaced by one for Ala in the PPET-1 cDNA. The mutant and wildtype PPET-1 cDNAs were expressed in COS-7 cells following transient transfection, and cell media and extracts, collected after 48 h, were assayed for ET-1 and big ET-1 by radioimmunoassay. The concentration of immunoreactive ET-1 in the medium obtained from the Ala-21-ET-1 mutant was 10-fold lower than that from PPET-1 wildtype and (Ala-20-ET-1) PPET-1 transfected cells. Moreover, Ala-21 -big ET-1 accumulated in the cells transfected with the cDNA for (Ala-21-ET-1) PPET-1, whereas there was no significant accumulation of ET-1-like or big ET-1-like immunoreactivity in the cells transfected with cDNAs for PPET-1 wildtype and (Ala-20-ET-1) PPET-1. These results suggest that Trp-21 is involved in intracellular processing and secretion of big ET-1.
UNDERSTANDING RAPID THEORETICAL CHANGE IN PARTICLE PHYSICS: A MONTH-BY-MONTH CO-CITATION ANALYSIS*

Abstract While co-citation analysis nas proved a powerful tool in the study of changes in intellectual foci in science, the technique has never been used to study very rapid changes in the theoretical structure of a scientific field. In this paper we present month-by-month co-citation analyses of key phases in the weak-electromagnetic unification research program within particle physics and show that these analyses capture and illuminate very rapid intellectual changes. These data provide yet another illustration of the utility of co-citation analysis for understanding the history of science.
Studies of Negative-Ion-Molecule Reactions in the Energy Region from 0 to 3 eV

A modulated retarding-potential-difference technique has been used to define the energy width of an electron beam located in the source region of a time-of-flight mass spectrometer. Negative ions with energies in the region 0-3 eV are produced by dissociative electron attachment to gas molecules in this source and are permitted to react for a controlled continuously variable length of time with neutral molecules to produce secondary negative-ion products. From the observed time development of the reactions, the reaction rate constant may be obtained, and the cross section then calculated if the primary-ion velocity is known. Results are presented for the reactions ${\mathrm{O}}^{\ensuremath{-}}$ + ${\mathrm{NO}}_{2}$ \ensuremath{\rightarrow} ${\mathrm{NO}}_{2}^{\ensuremath{-}}$ + O, ${\mathrm{H}}^{\ensuremath{-}}$ + ${\mathrm{H}}_{2}$O \ensuremath{\rightarrow} ${\mathrm{OH}}^{\ensuremath{-}}$ + ${\mathrm{H}}_{2}$, and ${\mathrm{D}}^{\ensuremath{-}}$ + ${\mathrm{D}}_{2}$O \ensuremath{\rightarrow} ${\mathrm{OD}}^{\ensuremath{-}}$ + ${\mathrm{D}}_{2}$ at a number of primary ion energies, and for the reactions ${\mathrm{O}}^{\ensuremath{-}}$ + ${\mathrm{N}}_{2}$O \ensuremath{\rightarrow} ${\mathrm{NO}}^{\ensuremath{-}}$ + NO, ${\mathrm{HCOO}}^{\ensuremath{-}}$ + S${\mathrm{F}}_{6}$ \ensuremath{\rightarrow} S${\mathrm{F}}_{5}^{\ensuremath{-}*}$ + (HCOOF), and S${\mathrm{F}}_{6}^{\ensuremath{-}}$ + HCl \ensuremath{\rightarrow} ${\mathrm{F}}_{2}$${\mathrm{Cl}}^{\ensuremath{-}}$ + (S${\mathrm{F}}_{4}$H) at single energy points.