cssi/SciSciGPT-SciSciNet huggingface dataset:
A novel mechanism of plasmin-induced mitogenesis in fibroblasts

The plasminogen activator/plasmin system is believed to play an important role in diverse pathophysiological processes, including wound healing, vascular remodeling and pulmonary fibrosis. Our recent studies show that plasmin upregulates the expression of Cyr61, a growth factor-like gene that has been implicated in cell proliferation and migration. In the present study, we investigated whether plasmin promotes fibroblast proliferation and, if so, determine the role of Cyr61 in the plasmin-induced response. Human lung fibroblasts were exposed to varying concentrations of plasmin and DNA synthesis was monitored by measuring the incorporation of 3H-thymidine into DNA. Plasmin increased DNA synthesis of fibroblasts in a dose-dependent manner. Protease-activated receptor-1 (PAR-1)-specific antibodies, but not PAR-2-specific antibodies, reduced the plasmin-induced DNA synthesis. Consistent with this, plasmin had no substantial effect on the DNA synthesis in PAR-1-deficient mouse fibroblasts. Plasmin activated both p38 and p44/42 MAPKs and specific inhibitors of these pathways inhibited the plasmin-induced DNA synthesis. Plasmin-induced increase in the DNA synthesis was completely abrogated by anti-Cyr61 antibodies. Interestingly, thrombin, which is a potent inducer of Cyr61, had only a minimal effect on fibroblast proliferation. Additional experiments suggested that plasmin cleaved cell/extracellular matrix-associated Cyr61 and the conditioned media from plasmin-treated cells could support the cell proliferation. Overall, these data suggest that plasmin promotes fibroblast proliferation by a novel pathway, involving two independent steps. In the first step, plasmin induces Cyr61 expression via activation of PAR-1, and in the second step, plasmin releases Cyr61 deposited in the extracellular matrix, thus making it accessible to act on cells.
Hypervitaminosis A in two hemodialysis patients

We present two cases of hemodialysis patients developing vitamin A toxicity related to excessive consumption of nutritional supplements containing large quantities of vitamin A. In one patient, severe hypercalcemia was the lone presenting sign; in the other, hypercalcemia was associated with unusual neurologic manifestations. We will discuss the reason why hemodialysis patients are at special risk for the development of hypervitaminosis A and review the mechanism leading to the associated hypercalcemia.
ODOR MIXTURES AND CHEMOSENSORY ADAPTATION IN GAS SENSOR ARRAYS

Inspired by the process of olfactory adaptation in biological olfactory systems, this article presents two algorithms that allow a chemical sensor array to reduce its sensitivity to odors previously detected in the environment. The first algorithm is based on a committee machine of linear discriminant functions that operate on multiple subsets of the overall sensory input. Adaptation occurs by depressing the voting strength of discriminant functions that display higher sensitivity to previously detected odors. The second algorithm is based on a topology-preserving linear projection derived from Fisher's class separability criteria. In this case, the process of adaptation is implemented through a reformulation of the between-to-within-class scatter eigenvalue problem. The proposed algorithms are validated on two datasets of binary and ternary mixtures of organic solvents using an array of temperature-modulated metal-oxide chemoresistors.
Electron-impact single ionization of multiply charged manganese ions

Absolute cross sections have been measured for single ionization of ${\mathrm{Mn}}^{q+}$ $(5l~ql~8)$ by electron impact at energies ranging from the ionization thresholds to 4 keV using a new dynamic-crossed-beams apparatus. The experimental cross sections are essentially featureless, but show evidence for significant contributions due to $3\stackrel{\ensuremath{\rightarrow}}{p}\mathrm{nl}$ $(ng~4)$ inner-shell excitation followed by autoionization for ${\mathrm{Mn}}^{5+}$ and ${\mathrm{Mn}}^{6+},$ and $3\stackrel{\ensuremath{\rightarrow}}{s}\mathrm{nl}$ $(ng~5)$ excitation-autoionization for ${\mathrm{Mn}}^{7+}$ and ${\mathrm{Mn}}^{8+}.$ The measurements for ${\mathrm{Mn}}^{6+}$ and ${\mathrm{Mn}}^{8+}$ and their interpretation are complicated by the presence of an undetermined fraction of the primary ion beams in metastable states.
Wire chamber requirements and tracking simulation studies for tracking systems at the superconducting super collider

Abstract Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tracking systems which meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum-bias background events, are examined. Results of some preliminary pattern recognition studies are given. Such computer simulation studies are necessary to determine the feasibility of wire chamber tracking systems for complex events in a high-rate environment such as the SSC.
Interhemispheric mass exchange from meteorological and trace substance observations

Two mechanisms contribute to interhemispheric mass exchange: large scale eddy transfer and mean meridional circulations. Estimates of both are presented based on data from a recently completed study of the general circulation of the tropics. The long term interhemispheric exchange time is found to be about 320 days. It is suggested that when eddy processes reinforce the transfer by mean meridional circulations in the upper troposphere in late spring and summer much faster exchange rates may occur which may be responsible for an apparent anomaly in the seasonal variation of surface ozone in the southern hemisphere. Finally the interhemispheric mass flux is compared with a crude estimate of the tropospheric-stratospheric mass flux based on the same tropical data. DOI: 10.1111/j.2153-3490.1969.tb00471.x
Poly(propylene imine) dendrimer conformations in the gas phase: a tandem mass spectrometry study

Abstract [M+H]+ ions are produced from a generation three poly(propylene imine) dendrimer (DAB-dendr-(NH2)16) by matrix-assisted laser desorption ionization (MALDI) or electrospray ionization (ESI), employing solvents of varying polarity and acidity for sample preparation (in MALDI) or the spraying process (in ESI). Subsequently, the structures of [M+H]+ are investigated by tandem mass spectrometry (MS/MS), via the post-source decay (PSD) and collisionally activated dissociation (CAD) techniques. Upon MALDI-PSD, elimination of the outer branches, i.e., of HN(CH2CH2CH2NH2)2 and HN[CH2CH2CH2N(CH2CH2CH2NH2)2]2, is observed with a polar protic but not with a nonpolar solvent. Similarly, the loss of the outer branches upon ESI-CAD is discriminated against when employing a nonpolar instead of a polar protic solvent. These differences are attributed to the existence of distinct conformations for the neutral dendrimer and the [M+H]+ ions formed from it. A nonpolar solvent leads to a folded conformation, i.e., one with the periphery branches pointing into the interior of the dendrimer to enable intramolecular hydrogen bonds. Due to such self-solvation, certain CN bonds cannot be cleaved efficiently upon MS/MS. On the other hand, a polar protic solvent interacts favorably with the dendrimer through intermolecular hydrogen bonds, promoting the formation of an extended, unfolded conformation from which outer and periphery branches can readily be eliminated. These structural differences disappear in the [M+2H]2+ cations produced by ESI; now, the loss of the outer branches takes place upon MS/MS irrespective of the solvent used in the ion generation step; this result is consistent with a stretched conformation for [M+2H]2+, where the repulsion between the like charges is minimized.
The effects of rotation and positional change of stump tissues upon morphogenesis of the regenerating axolotl limb.

Rotation of a skin cuff 180° around the proximodistal axis of the upper arm in the axolotl results in the formation of multiple regenerates in about 80° of cases after amputation of the limb through the rotated skin. Rotation of the dermis or the flexor and extensor muscles folowed by amputation produced similar percentages of multiple regenerates. Rotated bone produced no abnormalities, and rotated stump epidermis was minimally effective in stimulating multiple regeneration. A thin strip of normally oriented skin interposed between a rotated skin cuff and the amputation surface blocks the morphogenetic effect of the rotated stump skin whereas removal of the normal skin between a rotated proximal skin cuff and the amputation surface allows the formation of a low percentage of multiple regenerates. Gross rotation of stump tissue components can be broken down into axial rotation per se and positional dislocation. Experiments conducted upon skin and muscle have shown that positional dislocation along the anteroposterior axis rather than axial rotation is the manipulation that leads to the formation of multiple regenerates. The first morphological indication of multiple regeneration is the appearance of a triaxial apical ridge on the blastema. Subsequently, digits form along the apical ridges.
Some considerations of analytical chemical methodology relevant to testing of leachates from radioactive solids

Abstract The analysis of leachate derived from simulated radioactive solids provides an interesting challenge from both an instrumental and a chemical point of view. Because of the low anticipated leach rates, the elemental concentrations of interest are also low. Consequently, contamination or analytical blank problems are significant. Both the analyte (analyzed leachate) and the blank measurements have a statistical precision and therefore the difference between the two should have a calculable precision. Measurement accuracy, however, is not related to this calculated value. Without either knowing the absolute values in advance or having a sufficiently well characterized Standard Reference Material (SRM) it will not be possible to establish the absolute accuracy. Instrumental methods may produce a bias and extensive round robin tests alone do not establish the magnitude of these biases unless a suitable control or SRM material is used simultaneously. The largest anticipated chemical problem associated with trace and ultratrace element determinations in leach tests is that of sample contamination. Methods have been developed at the National Bureau of Standards (NBS) and other laboratories which can reduce or control contamination, however, it is important to realize that there are practical limits and contamination, per se, cannot be totally eliminated.
Brain potentials associated with recollective processing of spoken words

The neurocognitive foundations of recollection can be explored by recording event-related potentials (ERPs) from the human brain. In the present study, we monitored brain activity while participants heard a series of words, first in a study phase and again, 1–2 min later, in a test phase, when both priming and recognition were measured. Level of processing at study was manipulated within-subjects via instructions either to visualize the referent of each word (theimage task) or to detect the presence of target letters (theletter task). Priming of lexical decision response time was observed but did not differ across study task, whereas recognition was better for image- than for letter-task words. Brain potentials recorded at test revealed atask effect, wherein ERPs were more positive for image- than for letter-task words approximately 600–900 msec after word onset. The task effect was restricted to posterior scalp locations and was interpreted as an indication of visual imagery triggered by spoken words. Given that similar potentials were also elicited at study, we speculate that accurate recognition of words from the image task involved the recapitulation of the visual imagery that was initially engaged during the study phase.
Application of the Gas Chromatography-Fatty Acid Methyl Ester System for the Identification of Environmental and Clinical Isolates of the Family Micrococcaceae

Abstract Traditionally, the identification of microorganisms requested by industrial hygienists has been achieved by determining characteristics microscopically and using positive/negative biochemical tests. Specific assays designed to measure growth factor requirements, toxicity to selected animals, hemolysis and coagulase reactions, phage or plasmid typing, odor, colonial morphology (size, shape, pigmentation, etc.), and ability to grow on selective and differential media have had varying degrees of utility and may involve substantial subjectivity and estimation in the interpretation of results. Microbial Identification System (Microbial Identification, Inc., Newark, Delaware) was evaluated with 98 environmental and clinical American Type Culture Collection (ATCC®) strains of the family Micrococcaceae. This included 22 species (29 strains) of Staphylococcus and 5 species (8 strains) of Micrococcus. Overall accuracy of this investigation (correct to species level with 0.3 similarity index) based on singl...
Microwave scattering system design for ρe scale turbulence measurements on NSTX

Despite suppression of ρi scale turbulent fluctuations, electron thermal transport remains anomalous in NSTX. For this reason, a microwave scattering system will be deployed to directly observe the ω and k spectra of ρe scale turbulent fluctuations and characterize the effect on electron thermal transport. The scattering system will employ a Gaussian probe beam produced by a high power 280 GHz microwave source. A five-channel heterodyne detection system will measure radial turbulent spectra in the range |kr|=0–20 cm−1. Inboard and outboard launch configurations cover most of the normalized minor radius. Improved spatial localization of measurements is achieved with low aspect ratio and high magnetic shear configurations. This article will address the global design of the scattering system, such as choice of frequency, size, launching system, and detection system.
Prediction of Complex Task Proficiency by Means of Component Responses

The present study evolved from previous work on the relationship between a complex motor skill and its components (1957a). The objective was the fractionation of total-task behavior into individual part skills and the examination of relations between the parts and the total. The analysis leads to the synthesis of the complex skill. That is, a combinational rule is produced where the criterion score for the total task is reconstructed by means of the scores on the parts. Previous successful combinational rules were based upon models of independent probabilities (Bilodeau & Bilodeau, 1954; Bilodeau, 1955) and of multivariate regression . (Bilodeau, 1957b). A third approach (Bilodeau, 1957a), and also the one used here, make use of geometric relationships between the total and part tasks. There are two general types of training situations for which the synthesis can be made. In one, S practices the parts separately and is later tested with the parts simultaneously. In the other practice mode, training is confined to the total task. In the present experiment the training alternated between part and total tasks. S's task was to crank using two hands (total task) or one hand (part-task R and part-task L). The purpose was to show that the scores taken when the hands worked separately could be used to predict the scores when the hands worked together within a 5% margin of error. The practice of the part and whole tasks continued over a period of 20 days in order to ensure the development of more than an ordinary amount of coordination. It will be shown that (a) the problem of synthesizing whole-task performance is much simpler for skilled Ss than for the unskilled, and that (b) the terms of the combinational rule are suggestive of the nature of the developing coordination. METHOD Subjects.--On the basis of a brief foretest, three male graduate srudents were selected from five volunteers. The three Ss were chosen so as to maximize between-subject variance. Ss were paid $1.00 per hour plus a bonus for best and second best performance. Apparatus.-The appararus was Model CMlOlB of the Standard Two-Hand Coordination Test, modified as previously described (1957a) to change the cask from simple pursuit to tracing. Turning the crank for the right hand clockwise (C) or
Charge distribution and oxygen diffusion in hyperstoichiometric uranium dioxide UO2+x (x ⩽ 0.25)

Abstract Quantum–mechanical techniques were used to determine the charge distribution of U atoms in UO2+x (x ⩽ 0.25) and to calculate activation-energy barriers to oxygen diffusion. Upon optimization, the reduction in unit-cell volume relative to UO2, and the shortest 〈U–O〉 and 〈O–O〉 bond-lengths (0.22 and 0.24 nm, respectively) are in good agreement with experimental data. The addition of interstitial oxygen to the unoccupied cubic sites in the UO2 structure deflects two nearest-neighbor oxygen atoms along the body diagonal of uranium-occupied cubic sites, creating lattice oxygen defects. In (1 × 1 × 2) supercells, the partial oxidation of two U4+ atoms is observed for every interstitial oxygen added to the structure, consistent with previous quantum–mechanical studies. Results favor the stabilization of two U5+ over one U6+ in UO2+x. Calculated activation energies (2.06–2.73 eV) and diffusion rates for oxygen in UO2+x support the idea that defect clusters likely play an increasingly important role as oxidation proceeds.
Involuntary unemployment and worker self-selection☆

Abstract Consider a firm that lacks information about the reservation wage or ability of any specific worker, but is aware that workers with higher reservation wages tend to be more able, on average. We show that under a simple condition—that the efficiency wage exceeds the lowest reservation wage—the optimal hiring policy for the firm involves (1) no wage discrimination, and (2) rationing of jobs, when demand for its product is low. The result also extends to the case where hours of work are variable, provided each worker is most productive when working a strictly positive number of hours per week.
Missing-Cell Estimates in the Randomized Block Design with Random Effects

Abstract The classical missing-cell estimate used in the randomized block design is unbiased but does not have minimum variance when one or both effects are random. The unweighted least squares estimate of the appropriate cell mean is also unbiased and has smaller variance than the usual missing-cell formula in both mixed and random randomized block designs. This is illustrated using the cell-means model.
Bang-bang controls for parabolic and pseudoparabolic problems

We study the control of the family of problems where ? is a bounded domain in Rn, Q = ? × (0, T) and ? = ?? × (0, T) (1 - ??)y t (?) - ?y(?) = v(t)?(x) in Q y (?) (0) = 0 in ? y (?) | ? = 0 minimize J(v) = ??(y (?) (x,T;v) - z(x))dx subject to |v(t)| ? 1 a.e. in [0, T]. Existence, bang-bang, switching, and uniqueness properties are investigated. Further, conditions are studied which imply the almost everywhere convergence of the bang-bang controls as ? ? 0.
HIGH-PRECISION CALCULATION OF THE EQUATION OF STATE AND CRYSTALLOGRAPHIC PHASE STABILITY FOR ALUMINUM

High-precision, all-electron, full-potential, local-density approximation (LDA) calculations are used to determine the static lattice equation of state (EOS) and crystalline phase stability of Al to 1 TPa. The low-pressure properties found here are consistent with the results of other nonrelativistic LDA calculations, but differ significantly from the results of relativistic LDA or gradient-dependent approximation calculations. The theoretical 300-K isotherm for fcc Al, obtained by adding phonon effects to the static lattice EOS, is in reasonable agreement with room temperature data up to 220 GPa. The predicted static-lattice phase sequence for Al is fcc\ensuremath{\rightarrow}hcp\ensuremath{\rightarrow}bcc with the transitions occurring at 205\ifmmode\pm\else\textpm\fi{}20 GPa and 565\ifmmode\pm\else\textpm\fi{}60 GPa. Estimation of the possible impact of phonons on the fcc\ensuremath{\rightarrow}hcp transition produces a fairly firm upper bound of 290 GPa (282) on the room-temperature (zero temperature) fcc\ensuremath{\rightarrow}hcp transition pressure. This result suggests that a recent diamond-anvil-cell experiment came very close to achieving the fcc\ensuremath{\rightarrow}hcp transition. \textcopyright{} 1996 The American Physical Society.
The grasshopper neuroblast culture technique and its value in radiobiological studies.

A technique is described for the culture of grasshopper neuroblasts in which the neuroblast undergoes successive divisions at a relatively uniform rate through a total of 6 mitotic cycles over a period of 5 to 6 days at 26 deg C. Even after mitosis ceases, most of the embryonic cells live and undergo differentiation. Results are summarized from studies on the effects of different kinds of radiation on mitosis and on structure and behavior of various parts of the dividing cell. (C.H.)
Development of Y-123 coated conductors by ion-beam-assisted deposition

Abstract Continuous deposition of Gd2Zr2O7 films was carried out on 10 mm width Hastelloy tapes by ion-beam-assisted deposition (IBAD). They were uniformly deposited with the in-plane mosaic spread (Δφ) of 10–12° in the 15 m length and of 16–18° in the 60 m length, at a production rate of 1.0 m/h. In an optimized sample, Ic of 140 A and Jc of 1.2 MA/cm2 were obtained at the length of 8 cm. Continuous deposition of Y-123 films was performed by pulsed laser deposition on long IBAD template tapes at a tape speed of 1.0 m/h. Ic of 50.0 A and Jc of 0.42 MA/cm2 were obtained at the length of 9.6 m with Δφ for the Y-123 film was 9°. Furthermore, Ic of 50.0 A and Jc of 1.0 MA/cm2 were obtained in a 8 cm Y-123 sample with Δφ of 8° at a tape speed of 4.0 m/h.
Teaching Research Methodology Through Active Learning

ABSTRACT To complement traditional learning activities in a masters-level research methodology course, social work students worked on a formal research project which involved: designing the study, constructing measures, selecting a sampling strategy, collecting data, reducing and analyzing data, and finally interpreting and communicating the results. The final product was accepted in a respected, peer-reviewed journal. In the hopes of motivating social work educators to use active learning strategies when teaching research methods and to provide some pragmatic advice on how to do so, this article presents students' perceptions of involvement and lessons learned by the instructor. Through open- and closed-ended questions, students reported that involvement was meaningful, promoted understanding of research, strengthened relations among students, and made learning more exciting. Additionally, 41% of students reported that work on the project increased their interest in pursuing doctoral level work. Students...
Evaluating existing and new validity evidence for the Academic Motivation Scale

Abstract The current study evaluates existing and new validity evidence for the Academic Motivation Scale (AMS; Vallerand et al., 1992 ). We first provide a narrative review synthesizing past research, and then conduct a validity investigation of the scores from the measure. Data analysis using a sample of 1406 American college students provided construct validity evidence in the form of a well-fitting seven-factor model and adequate internal consistency of the item responses. Convergent and discriminant validity evidence provided insight into the distinctiveness of the seven subscales. However, support for the scale’s simplex structure, which would represent the self-determination theory continuum, was not fully substantiated. Implications for theory and the scale’s use in the current form are discussed.
Effects of front-surface target structures on properties of relativistic laser-plasma electrons.

We report the results of a study of the role of prescribed geometrical structures on the front of a target in determining the energy and spatial distribution of relativistic laser-plasma electrons. Our three-dimensional particle-in-cell simulation studies apply to short-pulse, high-intensity laser pulses, and indicate that a judicious choice of target front-surface geometry provides the realistic possibility of greatly enhancing the yield of high-energy electrons while simultaneously confining the emission to narrow ($l$${5}^{\ensuremath{\circ}}$) angular cones.
Toxoplasma: the next 100 years

It has been 100 years since Toxoplasma gondii was initially described in Tunis by Nicolle and Manceaux (1908) in the tissues of the gundi (Ctenodoactylus gundi) and in Brazil by Splendore (1908) in the tissues of a rabbit. T. gondii is a ubiquitous, Apicomplexan parasite of warm-blooded animals that can cause several clinical syndromes including encephalitis, chorioretinitis and congenital infection. Due to the extensive repertoire of applicable experimental techniques available for this pathogen it has become a model organism for the study of intracellular pathogens. Data obtained from genome-wide expression studies, including ChIP on chip and proteomics surveys, are refining our understanding of the genetic networks involved in the developmental biology of this pathogen as well as the interactions of the parasite with its host. This review addresses recent advances in our understanding of the developmental biology and host-pathogen relationships of T. gondii.
Minireview: Won't get fooled again: The nonmetabolic roles of peroxisome proliferator-activated receptors (PPARs) in the heart

The peroxisome proliferator-activated receptor (PPAR) transcription factors are nuclear receptors initially identified for their key role in regulating metabolic processes. Recent studies designed to identify the role of PPARα, -β, and -γ in vivo uncovered extrametabolic roles that may be less well known in the heart. In this review, we describe what is known about these extrametabolic roles of PPARs, including regulation of cardiac inflammation, extracellular matrix remodeling, oxidative stress, and regulation of cardiac hypertrophy. Lastly, we discuss the emerging role of PPARs in cell cycle regulation and angiogenesis in noncardiac systems that may be applicable to heart biology. Although this review primarily discusses the extrametabolic role of PPARα, the most studied PPAR isoform in the heart, we highlight where possible what is known about the unique and overlapping roles of the PPAR isoforms in terms of metabolic function.
Nutrition and physiology of denitrifying bacteria

The size of both the denitrifying and the total bacterial population was found to be positively correlated with soil pH, but the denitrifying bacteria were more sensitive to acid environments than the bacterial microflora as a whole. The ecological evidence for a pH effect was supported by studies with individual pure cultures. The estimate of abundance of denitrifying micro-organisms was also affected markedly by the composition of the medium, and an improved medium has been proposed. Marked differences were noted in the nutrition of the bacteria capable of N2 production. In the absence of oxygen, certain strains developed readily using nitrate as the terminal electron acceptor for growth in media with no preformed growth factors, but others required ammonium or growth factors for denitrification to occur.
A Subjective Study of the Nutritional Intake of Patients with Spina Bifida

Abstract This study was conducted in routine multi disciplinary Spina Bifida Clinics. A two page descriptive questionnaire was given to 53 patients enabling us to assess and compare selected nutrients. A Nurse Specialist provided information on success (or lack there of) in achieving proper stooling consistency. Data were analyzed for patterns in fluid intake, calcium intake, frequency and variability of fruit and vegetable intake. Constipation tendencies as perceived by the parent and the Nurse Specialist were also obtained. Twelve percent of the participants were taking less than or equal to 50% of their fluid needs for the day. Twenty-six percent were taking less than or equal to 50% of their calcium needs for the day. Thirty-six percent of the participants had only one or fewer servings of fruit and vegetables/day (not counting juice and potato). Of those individuals, 9 out of 19 (17%) listed 10 or fewer fruits and vegetables as being "liked". However, 10 out of 19 (19%) liked at least 10 or more different fruits and vegetables, but do not appear to routinely eat them. Our Nurse Specialist defined 54% of the patients as being constipated. Thirty-four percent of the parents defined their child as being constipated. The nurse and the parents agreed on constipation tendencies in 29 out of 53 cases (55%) of the time. This study supports the need for Medical Nutrition Therapy to educate this patient population on calcium needs, hydration, adequate fiber intake, and constipation issues.
A (3H)-thymidine autoradiographic study of cell proliferative activity of injured parodontal tissues of 5-week-old mice.

Abstract Evaluation of the cell proliferative changes which occur in response to trauma in young mice was investigated autoradiographically. Forty-four 5 week-old female mice of the short-lived Brookhaven National Laboratory (BNL) strain were gingivectomized surgically, removing the papilla mesial to the maxillary first molar. One hour prior to death, each animal received 1.0 μCi of tritiated thymidine per g of body weight by subcutaneous injection. Following death, the maxillae were removed, and the appropriate tissues were prepared for histologic and autoradiographic studies. Labelling indices were determined of various parodontal tissue cell compartments. The results were compared with previously published control values and rat data. Response of the mouse parodontal tissues to injury was, by and large, similar to that of the rat, with the exception that the proliferative activity of mouse tissues was significantly lower and occurred sooner following injury. The differences do not appear to be biologically significant in young animals. On the basis of the present findings, it was concluded that the size of the normal proliferative activity cannot be taken as (1) an index of the rate of repair, (2) an indication of the required length of repair, or (3) a measure of the proliferative capacity of the tissue. Normal labelling indices reflect only the level of cell turnover occurring in a given cell compartment, at a given anatomical site, in response to current physiological demands of the organism.
Nano Building Blocks via Iodination of [PhSiO1.5]n, Forming [p-I-C6H4SiO1.5]n (n = 8, 10, 12), and a New Route to High-Surface-Area, Thermally Stable, Microporous Materials via Thermal Elimination of I2

We describe the synthesis and characterization of the homologous p-iodophenylsilsesquioxanes (SQs) [p-I-C(6)H(4)SiO(1.5)](n) (n = 8, 10, 12) via ICl-promoted iodination (-40 to -60 degrees C) with overall yields of 80-90% and > 95% para selectivity following recrystallization. Characterization by NMR, FTIR, TGA, and single-crystal X-ray diffraction are reported and compared to data previously published for I(8)OPS. Coincidentally, we report a new synthesis of the elusive pentagonal decaphenyl SQ (dPS) [C(6)H(4)SiO(1.5)](10) and its characterization by NMR and single-crystal X-ray studies. These unique macromolecules possess equivalent chemical functionality but varying symmetries (cubic, pentagonal, and D(2d) dodecahedral), offering the potential to develop homologous series of functionalized star and dendrimer compounds with quite different core geometries and thereby providing the potential to greatly vary structure-property relationships in derivative compounds and nanocomposites made therefrom. We find that all three compounds decompose on heating to approximately 400 degrees C/N(2) with loss of I(2) to form robust, microporous materials with BET surface areas of 500-700 m(2)/g, pore volumes of 0.25-0.31 cm(3)/g, average pore widths of 8 A, and oxidative stabilities > or = 500 degrees C and with solid-phase morphologies varying from crystalline to mostly amorphous, as indicated by powder XRD and SEM studies. These latter findings point to important symmetry effects relating directly to packing in the crystalline phase prior to thermolysis.
Genetic influences on tissue deposition of aluminum in mice

Aluminum is a known neurotoxin and has been suggested to play a role in the development of Senile Dementia of the Alzheimer's Type. The relationship between aluminum exposure and senile dementia cannot be a simple one, however, as not all exposure results in neurotoxic manifestations. To determine if there are genetic differences in susceptibility to moderate aluminum exposure, 16 mice of five inbred strains were divided into two groups. The control group was fed a purified diet containing all known requirements for mice; the experimental group was fed the same diet supplemented with 260 mg Al/kg diet for 28 d. Analysis of brains, livers, and tibias for aluminum concentrations revealed strain differences in response to dietary treatment. The most notable results occurred in the DBA/2 and C3H/2 strains, with brain aluminum levels higher in the experimental groups. In contrast, A/J, BALB/c, and C57BL/6 strains showed no differences in brain aluminum in response to dietary treatment. These findings suggest that there are genetic differences in the permeability of the blood brain barrier and lend support to the hypothesis that variability in aluminum toxicity may be, in part, genetically determined.
Building Trust to Relieve Graduate Student Research Anxiety

This paper outlines the case studies of two librarians who work closely with graduate students in fine arts programs. Realizing that graduate students can often experience a unique form of research anxiety, both librarians collaborated with faculty to embed themselves into the research methods courses of their programs. Both librarians found that the chance to work one-on-one with graduate students resulted in a reduction of their anxiety, an increase in information literacy skills, and a strengthened partnership between the librarians and the departments.
The effect of copper sprays and fertilization on bacterial canker in French prune

Bacterial canker, caused by Pseudomonas syringae pv. syringae or Pseudomonas syringae pv. morsprunorum, is one of the most economically important diseases of stone-fruit trees; it occurs worldwide in all commercially grown Prunus spp. Field trials were conducted on French prune (Prunus domestica) to evaluate the efficacy of copper sprays and N–P–K fertilization, separately and in combination, on the severity and incidence of this disease. A zinc sulfate defoliant spray was also tested to determine if premature leaf removal would prevent bacterial canker by initiating an earlier and rapid healing of leaf scars before epiphytic populations of the pathogen gained access to the cambium through the leaf scars. A visual rating system of 0 to 5 was used to quantify the incidence and severity of bacterial canker and the associated tree mortality. Results indicate that the combination of copper sprays throughout the dormant season in combination with the biannual application of N–P–K plus micronutrients significan...
Degradation of milk-based bioactive peptides by yogurt fermentation bacteria.

Aims: To analyse the effect of cell-associated peptidases in yogurt starter culture strains Lactobacillus delbrueckii ssp. bulgaricus (LB) and Streptococcus thermophilus (ST) on milk-protein-based antimicrobial and hypotensive peptides in order to determine their survival in yogurt-type dairy foods. Methods and Results: The 11mer antimicrobial and 12mer hypotensive milk-protein-derived peptides were incubated with mid-log cells of LB and ST, which are required for yogurt production. Incubations were performed at pH 4·5 and 7·0, and samples removed at various time points were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC). The peptides remained mostly intact at pH 4·5 in the presence of ST strains and moderately digested by exposure to LB cells. Peptide loss occurred more rapidly and was more extensive after incubation at pH 7·0. Conclusions: The 11mer and 12mer bioactive peptides may be added at the end of the yogurt-making process when the pH level has dropped to 4·5, limiting the overall extent of proteolysis. Significance and Impact of the Study: The results show the feasibility of using milk-protein-based antimicrobial and hypotensive peptides as food supplements to improve the health-promoting qualities of liquid and semi-solid dairy foods prepared by the yogurt fermentation process.
Joint MMSE designs for analog network coding and different MIMO relaying schemes: A unified approach and performance benchmarks

Abstract To gain understanding of the analog network coding and different MIMO relaying schemes and to facilitate the scheme selection, there is a need for a unified approach and performance benchmarks. In this paper, analog network coding, direct transmission, Two-Hop relaying, and cooperative relaying schemes are analyzed and compared. A unified approach, the novel generalized iterative approach, is proposed for jointly designing the MMSE MIMO processors (including precoders, relay processors and decoders) for these schemes. Numerical results show that for each scheme, there exist system and channel parameter regime(s) where it is the most desirable among the four schemes. Performance benchmarks, physical insights and some guidelines for MIMO relaying scheme selection are presented.
Functional Consequences of Subunit Diversity in RNA Polymerases II and V

Multisubunit RNA polymerases IV and V (Pol IV and Pol V) evolved as specialized forms of Pol II that mediate RNA-directed DNA methylation (RdDM) and transcriptional silencing of transposons, viruses, and endogenous repeats in plants. Among the subunits common to Arabidopsis thaliana Pols II, IV, and V are 93% identical alternative ninth subunits, NRP(B/D/E)9a and NRP(B/D/E)9b. The 9a and 9b subunit variants are incompletely redundant with respect to Pol II; whereas double mutants are embryo lethal, single mutants are viable, yet phenotypically distinct. Likewise, 9a or 9b can associate with Pols IV or V but RNA-directed DNA methylation is impaired only in 9b mutants. Based on genetic and molecular tests, we attribute the defect in RdDM to impaired Pol V function. Collectively, our results reveal a role for the ninth subunit in RNA silencing and demonstrate that subunit diversity generates functionally distinct subtypes of RNA polymerases II and V.
Multiple Variable Sources of Reactive Power on Distribution System Primary Feeders

An analysis of the performance of multiple variable sources of reactive power on distribution system primary feeders is presented. Necessary conditions for optimally siting, sizing and operating an arbitrary number of such devices are developed. Performance is compared to that of comparable fixed capacitor bank installations.
P 3 : a manufacturing planner that reasons about cost-effective plans to achieve positional tolerance specifications

Abstract This paper describes the operation of the process planner, P 3 , and a set of validation tests of P 3' s performance. The objective behind this work is to provide a computer model to be used by designers as a resource of manufacturing knowledge which can help in assessing the manufacturability and cost of particular designs. P 3 is a process planner for use in small batch planning on 3-axis machining centers, P 3 produces cost-effective plans. It can explicitly reason about positional tolerance specifications; it takes advantage of looser tolerance specifications to produce lower cost plans when possible. P 3 is a heterogeneous, constraint-based planner which uses both case-based and generative techniques to suit different parts of the problem. This planner has been incorporated into a design tool called the Manufacturing Evaluation Agent which generates cost-saving design suggestions. Problem-solving models, such as P 3 , form an important part of human-computer collaborative tools in concurrent engineering environments.
TWO-DIMENSIONAL CRYSTALLIZATION OF BRUSH BORDER MYOSIN I

Brush border myosin-I (BBMI) is a single-headed unconventional myosin found in the microvilli of intestinal epithelial cells, where it links the core bundle of actin filaments to the plasma membrane. An association of BBMI with anionic phospholipids has been shown to be mediated by a carboxy-terminal domain which is rich in basic amino acids. We have exploited this natural affinity of BBMI for negatively charged lipids to form two-dimensional (2D) crystals of this protein which are suitable for structural analysis by electron crystallographic techniques. The 2D crystals which we have obtained belong to one of two space groups, p22121 or p2. We present here projection maps calculated from images of negatively stained crystals for each of these crystal types to a resolution of 20 A and show that the asymmetric unit is the same in both crystal types.
Evaluation of the depth-integration method of measuring water discharge in large rivers

Abstract The depth-integration method oor measuring water discharge makes a continuos measurement of the water velocity from the water surface to the bottom at 20 to 40 locations or verticals across a river. It is especially practical for large rivers where river traffic makes it impractical to use boats attached to taglines strung across the river or to use current meters suspended from bridges. This method has the additional advantage over the standard two- and eight-tenths method in that a discharge-weighted suspended-sediment sample can be collected at the same time. When this method is used in large rivers such as the Missouri, Mississippi and Ohio, a microwave navigation system is used to determine the ship's position at each vertical sampling location across the river, and to make accurate velocity corrections to compensate for shift drift. An essential feature is a hydraulic winch that can lower and raise the current meter at a constant transit velocity so that the velocities at all depths are measured for equal lengths of time. Field calibration measurements show that: (1) the mean velocity measured on the upcast (bottom to surface) is within 1% of the standard mean velocity determined by 9–11 point measurements; (2) if the transit velocity is less than 25% of the mean velocity, then average error in the mean velocity is 4% or less. The major source of bias error is a result of mounting the current meter above a sounding weight and sometimes above a suspended-sediment sampling bottle, which prevents measurement of the velocity all the way to the bottom. The measured mean velocity is slightly larger than the true mean velocity. This bias error in the discharge is largest in shallow water (approximately 8% for the Missouri River at Hermann, MO, where the mean depth was 4.3 m) and smallest in deeper water (approximately 3% for the Mississippi River at Vickbsurg, MS, where the mean depth was 14.5 m). The major source of random error in the discharge is the natural variability of river velocities, which we assumed to be independent and random at each vertical. The standard error of the estimated mean velocity, at an individual vertical sampling location, may be as large as 9%, for large sand-bed alluvial rivers. The computed discharge, however, is a weighted mean of these random velocities. Consequently the standard error of computed discharge is divided by the square root of the number of verticals, producing typical values between 1 and 2%. The discharges measured by the depth-integrated method agreed within ±5% of those measured simultaneously by the standard two- and eight-tenths, six-tenth and moving boat methods.
Sterility and gene expression in hybrid males of Xenopus laevis and X. muelleri

Background. Reproductive isolation is a defining characteristic of populations that represent unique biological species, yet we know very little about the gene expression basis for reproductive isolation. The advent of powerful molecular biology tools provides the ability to identify genes involved in reproductive isolation and focuses attention on the molecular mechanisms that separate biological species. Herein we quantify the sterility pattern of hybrid males in African Clawed Frogs (Xenopus) and apply microarray analysis of the expression pattern found in testes to identify genes that are misexpressed in hybrid males relative to their two parental species (Xenopus laevis and X. muelleri). Methodology/Principal Findings. Phenotypic characteristics of spermatogenesis in sterile male hybrids (X. laevis x X. muelleri) were examined using a novel sperm assay that allowed quantification of live, dead, and undifferentiated sperm cells, the number of motile vs. immotile sperm, and sperm morphology. Hybrids exhibited a dramatically lower abundance of mature sperm relative to the parental species. Hybrid spermatozoa were larger in size and accompanied by numerous undifferentiated sperm cells. Microarray analysis of gene expression in testes was combined with a correction for sequence divergence derived from genomic hybridizations to identify candidate genes involved in the sterility phenotype. Analysis of the transcriptome revealed a striking asymmetric pattern of misexpression. There were only about 140 genes misexpressed in hybrids compared to X. laevis but nearly 4,000 genes misexpressed in hybrids compared to X. muelleri. Conclusions/Significance. Our results provide an important correlation between phenotypic characteristics of sperm and gene expression in sterile hybrid males. The broad pattern of gene misexpression suggests intriguing mechanisms creating the dominance pattern of the X. laevis genome in hybrids. These findings significantly contribute to growing evidence for allelic dominance in hybrids and have implications for the mechanism of species differentiation at the transcriptome level.
A convenient synthesis of azetidine-2,3-diones (α-Keto-β-Lactams)☆

Abstract Azetidine-2,3-diones can be conveniently synthesized by mild hydrolysis of the product of the reaction between α-phenylthio-β-lactams and sulfuryl chloride.
Gas-Phase Chemistry of Vanadium Oxide Cluster Cations. 1. Reactions with C2F6 and CH3CF3

The reactivities of mass-selected vanadium oxide cluster cations with fluorocarbons were studied by using a triple-quadrupole mass spectrometer coupled with a laser vaporization source. The vanadium oxide species V2O4-7+, V3O6-9+, V4O8-11+, V5O11-13+, V6O13-16+, and V7O16-18+ displayed unique reactivities with CH3CF3 and C2F6. Among the reaction pathways observed were association, HF elimination, cracking of the carbon−carbon bond, and fluorine abstraction with oxygen transfer from the cluster to the neutral reactant molecule. Interestingly, the reactions differed for clusters within the same series and also from series to series. For example, the reaction of V2O4+ with CH3CF3 produces the HF-elimination product V2O4·HF+. However, the cluster V2O5+ reacts with CH3CF3 to produce the cracking product V2O5·CF3+ but also reacts to abstract 2 fluorine atoms with transfer of an oxygen atom to the neutral reactant molecule. The reaction of these 2 clusters with C2F6 generates only association products.
Performance evaluation of discrete event systems via stepwise reduction and approximation of stochastic Petri nets

The authors present a stepwise reduction and approximation method for generalized stochastic Petri nets (GSPNs) in order to reduce their state space. When a subnet is reduced to a simpler structure, not only the qualitative properties but also quantitative characteristics such as token flow rates are preserved. The authors first define various kinds of potentially reducible subnets and then present rules on subnet selection, approximation subnet construction, and reduction evaluation. Two criteria for judging a reduction step are the number of states in the subnets and the final net during the reduction process and the error resulting whenever the exact value is possible. A discrete event system which models a computer system is used as an example to illustrate the procedure. >