cssi/SciSciGPT-SciSciNet huggingface dataset:
The Development of a Computer-Based Alternate Assessment System

This article describes the development of an alternate assessment system for students with moderate to severe disabilities. The system integrates what is known about effective feedback in classroom assessment with broader requirements for system accountability under the 1997 Amendments to the Individuals with Disabilities Education Act (Public Law 105-17). The alternate assessment provides teachers with customized computer software and documentation tools that are used to collect meaningful student performance data from multiple sources on an ongoing basis. The assessment system evolved through an extensive committee process during which input from a variety of stakeholders was sought. The development process is summarized and the computer-based rating and documentation system is described, including the technical adequacy of the resulting alternate assessment.
Fractionation trends in mica and tourmaline as indicators of pegmatite internal evolution: Bob Ingersoll pegmatite, Black Hills, South Dakota☆

Abstract Pegmatitic micas from the Bob Ingersoll No. 1 Dike, a large, internally zoned, rare element pegmatite body, have been analyzed for trends of compositional variation that indicate the sequence of crystallization and record the progressive compositional differentiation of the pegmatite. The dike consists of six primary zones and one replacement assemblage. 2M1, muscovite occurs in the border and wall zones and outer parts of the first intermediate zone. Intermediate-Li micas of mixed polytype, but with a dominant 2M1 component, occur in inner parts of the pegmatite, including the core and areas of contact between intermediate zones and the core. 2M2 lepidolite occurs as a replacement of K-feldspar along margins between the first intermediate zone and core. Fractionation trends of the micas include increasing Li substitution, decreasing Rb Cs and increasing Ta (Nb + Ta) in a general sequence from the outer wall zone to the pegmatite core, but with considerable overlap among intermediate zones. When compared to coexisting tourmaline, overlapping compositional trends of the interior zones suggest overlap in timing of crystallization and interzonal geochemical communication. Border zone mineral compositions do not fit major variation trends due to the combined effects of wallrock contamination, replacement of early microcline by lithian mica during differentiation of the pegmatite, and possibly rapid, disequilibrium crystallization. Strong zoning of mica and tourmaline crystals reflects disequilibrium conditions as crystalline pegmatite reacted with compositionally evolving fluids. Lithian mica and lepidolite that replaced early-formed K-feldspar may have been generated by fluids that were in equilibrium with a residual silicate melt in the pegmatite core. Aqueous fluids exsolved from silicate melt appear to have leaked from the pegmatite throughout much of its crystallization history, and the late stage Li, Rb, and Cs-enriched fluids contributed to the exomorphic halo surrounding the pegmatite.
Age-dependent Participation of Ras-GRF Proteins in Coupling Calcium-permeable AMPA Glutamate Receptors to Ras/Erk Signaling in Cortical Neurons

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptors (AMPARs) are ligand-gated sodium channels. Through their ability to mediate the majority of rapid excitatory transmission in the central nervous system, these neurotransmitter receptors have been shown to influence synaptic plasticity. Some of these receptors are also calcium-permeable (CP), and they also have been implicated in regulating synaptic plasticity, particularly in interneurons where their concentration is highest. However, the biochemical pathways emanating from CP-AMPARs that mediate these effects have not been well characterized. In this paper, we show that CP-AMPARs are the predominant AMPAR class responsible for activating the Ras/Erk kinase signaling cascade and the cAMP-response element-binding protein (CREB) transcription factor in the cortex of mature mice. Activation of Ras and Erk, but not CREB, occurs through the calcium/calmodulin regulated Ras-GRF1 and Ras-GRF2 exchange factors, which form AMPA-induced complexes with CP-AMPARs but not calcium-impermeable (CI) AMPARs in vivo. Furthermore, we show that CP-AMPARs are also the major AMPAR type to activate Ras/Erk signaling in pubescent mice; however, at this developmental stage Ras-GRF (guanine nucleotide-releasing factor) proteins are not involved. Finally, in neonatal animals CI-AMPARs, but not CP-AMPARs, are the predominant AMPAR type that activates Ras-Erk signaling and CREB in cortical neurons. This occurs indirectly through activation of L-type voltage-dependent calcium channels, an event that is also Ras-GRF-independent. Thus, Ras/Erk signaling and CREB activity induced by AMPARs occur through age-dependent mechanisms that likely make unique developmentally dependent contributions to synaptic function.
Yvor Winters and the educated sensibility in antiquity

In response to the types of scepticism from the 18th through the early 20th centuries which did most to question the criteria of all artistic evaluation, Winters states his intention “to fix in literary terms some approximation of a classical state of mind.” This state of mind is most clearly anticipated by the confidence in the cognitive resources of the senses and of the educated sensibility as affirmed by the Old Academy and its principal beneficiary, Aristotle. The subsequent scepticisms of the Hellenistic period resemble those that later confronted Winters, while the attempt of someone like Antiochus of Ascalon to escape them by returning to the views of the Old Academy in the Roman period corresponds to Winters’ own repeated invocations of the authority of Aristotle.
Laparotomy for acute colorectal conditions in moribund patients: is it worthwhile?

Colorectal surgeons are sometimes asked to operate on moribund patients, classified by the American Society of Anesthesiology as Class 5—patients who are likely to die with or without surgery. There is a concern that surgery may precipitate the patient’s demise; however, there are few data concerning outcomes in this group. It is, therefore, difficult to counsel patients and their families about the advisability of surgery. This study was performed to show what sort of results can be expected from operating on American Society of Anesthesiology Class 5 patients and to see whether there are any factors that can be used to predict outcome within this American Society of Anesthesiology class. Since March 1989, a prospective database of all surgeries has been maintained. Included in the data is the American Society of Anesthesiology Classification. All patients classified as 5 were identified and their history reviewed. The 30-day postoperative survival was the primary end point of the study. Also abstracted were data on comorbidity, indication for colorectal surgery, surgery performed, length of postoperative hospital stay, estimated intraoperative blood loss, and duration of anesthesia. There were 4,163 surgeries recorded, including 2,040 (49 percent) laparotomies. There were 21 laparotomies in American Society of Anesthesiology Class 5 patients (1 percent of all laparotomies). Eighteen surgeries were performed as emergencies, and three were urgent. Nine patients survived 30 days or longer (41 percent), whereas 12 did not. Seven patients lived to be discharged from the hospital. Expeditious, safe surgery may save moribund patients with an acute colorectal problem.
Thermal conductivity of disordered garnets from infrared spectroscopy

The thermal conductivity (k) of garnets is calculated from a formula originating with Debye, adapted to treat the vibrations in a solid as a collection of damped harmonic oscillators. Our model utilizes phonon lifetimes obtained from Kramers-Kronig analyses of existing IR reflectivity spectra, as well as new data presented here, and calculates k at ambient conditions within a nominal uncertainty of 6% of the experimental values for eight natural samples with well-constrained chemical compositions. Agreement is good for the remaining garnets with uncertain compositions. Two series of natural mixed crystals were studied: (1) ${X}_{3}{\mathrm{Al}}_{2}{\mathrm{Si}}_{3}{\mathrm{O}}_{12},$ where the X site has varying amounts of Mg, ${\mathrm{Fe}}^{2+},$ and Ca and (2) ${\mathrm{Ca}}_{3}{Y}_{2}{\mathrm{Si}}_{3}{\mathrm{O}}_{12},$ where the Y site has Al and/or ${\mathrm{Fe}}^{3+}.$ The model predicts k at ambient conditions for the end members. The occurrence of a minimum in k near the midpoint of each compositional series correlates with the maximum widths of the IR peaks. Thus, disorder on crystallographic sites largely controls the thermal conductivity of mixed crystals. We also tested the model using available data on synthetic yttrium garnets. Agreement is good for YAG. Observation of $\ensuremath{\sim}30%$ discrepancy between calculated and experimental k of YGG and YIG suggests that these unconfirmed measurements should be repeated.
1,2-Eliminations from (CH3)2NH+CH2CH3 and (CH3)2NH2+: guided dissociations.

1,2-Eliminations are a varied and extensive set of dissociations of ions in the gas phase. To understand better such dissociations, elimination of CH2=CH2 and CH3CH3 from (CH3)2NH+CH2CH3 (1) and of CH4 from (CH3)2NH2+ are characterized by quantum chemical calculations. Stretching of the CN bond to ethyl is followed by shift of an H from methyl to the bridging position in ethyl and then to N to reach (CH3)2NH2+ + CH2=CH2 from 1. CH3CH3 elimination by H-transfer to C2H5+ to form CH3NH+=CH2 + CH3CH3 also takes place. (CH3)2NH2+ eliminates methane by CN bond extension followed by β-H-transfer to give CH2=NH+ + CH4. Low-energy reactions resembling complex-mediated 1,2-eliminations occur and constitute a hitherto largely unrecognized type of reaction. As in many complex-mediated reactions, these reactions transfer H between incipient fragments. They are distinguished from complex-mediated processes by the fragments not being able to rotate freely relative to each other near the transition state for reaction, as they do in complexes. Most 1,2-eliminations are ion-neutral complex-mediated, occur by the just described lower energy reactions, have 1,1-like transition states, or utilize highly asynchronous 1,2 transition states. All of these avoid synchronized 1,2-transition states that would violate conservation of orbital symmetry.
Habit reversal vs negative practice treatment of self-destructive oral habits (biting, chewing or licking of the lips, cheeks, tongue or palate).

Abstract Ten patients with oral habits such as biting, chewing, licking, or pushing of the cheeks, lips, teeth, or palate were randomly assigned to either habit reversal treatment or to negative practice treatment. Treatment was given in a single 2-hr session. The patients receiving negative practice treatment showed a mean reduction of about 65%, those receiving the habit reversal treatment showed a mean reduction of about 99% during the 22-months of follow-up.
Reversed-phase separation of optical isomers of Dns-amino acids and peptides using chiral metal chelate additives☆

Abstract This paper is a continuation of the study of metal chelate additives to the mobile phase in reversed-phase liquid chromatography for the achievement of selective separations. In particular, through the use of the chiral chelate, l -2-isopropyl-4- octyl-diethylenetriamine-Zn(II), all common amino acids, with the exception of proline, as well as a number of other amino acids have been resolved into their optical isomers as their Dns derivatives. Remarkably high relative retentions are achieved, permitting rapid chiral separation of individual amino acids. Based on a study of pH and ionic strength, it is suggested that a selective interaction in basic media (pH 9) involves the electrostatic bidentate attachment of the Dns solute to the metal chelate. Attachment occurs through the carboxylate anion and the anion of the sulfonamide group whose proton is lost in the presence of the metal acid center. Other studies examined the role of metal ion on separation. In particular, when Ni(II), Cd(II), and Cu(II) were employed, differences in retention and selectivity were found. Interestingly, wen Hg(II) was substituted for Zn(II), the elution order for d,l -Dns- amino acids was inverted, thus providing a simple means for checking chiral separations. Resolution of optical isomers of chiral dipeptides using Ni(II) chelate is also shown. Finally, several applications of this approach are discussed. Since little or no recemization was found in the dansylation reaction or upon standing, rapid assessment of optical purity of free amino acids was possible.
Depletion of F-actin Near Surfaces

Proximity to membranes is required of actin networks for many key cell functions, including mechanics and motility. However, F-actin rigidity should hinder a filament's approach to surfaces. Using confocal microscopy, we monitor the distribution of fluorescent actin near non-adherent glass surfaces. Initially uniform, monomers polymerize to create a depletion zone where F-actin is absent at the surface but increases monotonically with distance from the surface. At its largest, depletion effects can extend >35 μm, comparable to mass-weighted filament lengths. Increasing the rigidity of actin filaments with phalloidin increases the extent of depletion, whereas shortening filaments using capping protein reduces it proportionally. In addition, depletion kinetics are faster with higher actin concentrations, consistent with faster polymerization and faster Brownian-ratchet-driven motion. Conversely, the extent of depletion decreases with actin concentration, suggesting that entropy is the thermodynamic driving force. Quantitatively, depletion kinetics and extent match existing actin kinetics, rigidity and lengths. However, explaining depletion profiles and concentration-dependence (power-law of -1) requires modifying the rigid rod model. Dynamically crosslinked and dendritic (ARP2/3) networks either slow or enhance the extent of depletion, respectively. In cells, surface depletion should slow membrane-associated F-actin reactions another ∼10-fold beyond hydrodynamic considerations, and to favor membrane invaginations by decreased surface tension. Similar depletion principles underlie the thermodynamics of all surface-associated reactions with mechanical structures, ranging from DNA to filaments to networks. For various functions, cells must actively resist the thermodynamics of depletion.
Solid-state densification of spun-cast self-assembled monolayers for use in ultra-thin hybrid dielectrics

Abstract Ultra-thin self-assembled monolayer (SAM)-oxide hybrid dielectrics have gained significant interest for their application in low-voltage organic thin film transistors (OTFTs). A [8-(11-phenoxy-undecyloxy)-octyl]phosphonic acid (PhO-19-PA) SAM on ultrathin AlO x (2.5 nm) has been developed to significantly enhance the dielectric performance of inorganic oxides through reduction of leakage current while maintaining similar capacitance to the underlying oxide structure. Rapid processing of this SAM in ambient conditions is achieved by spin coating, however, as-cast monolayer density is not sufficient for dielectric applications. Thermal annealing of a bulk spun-cast PhO-19-PA molecular film is explored as a mechanism for SAM densification. SAM density, or surface coverage, and order are examined as a function of annealing temperature. These SAM characteristics are probed through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure spectroscopy (NEXAFS). It is found that at temperatures sufficient to melt the as-cast bulk molecular film, SAM densification is achieved; leading to a rapid processing technique for high performance SAM-oxide hybrid dielectric systems utilizing a single wet processing step. To demonstrate low-voltage devices based on this hybrid dielectric (with leakage current density of 7.7 × 10 −8 A cm −2 and capacitance density of 0.62 μF cm −2 at 3 V), pentacene thin-film transistors (OTFTs) are fabricated and yield sub 2 V operation and charge carrier mobilites of up to 1.1 cm 2 V −1 s −1 .
Fine-needle aspiration of a periurethral Teflon-filled cyst following radical prostatectomy

Periurethral Teflon injections are being used increasingly for the treatment of urinary incontinence after radical prostatectomy. We report a case of a man who developed increasing obstructive urinary symptoms and stress incontinence following radical retropubic prostatectomy. Six months earlier, he had undergone periurethral Teflon injections. On transrectal ultrasound and magnetic resonance imaging, a 3.2-cm cystic lesion was noted at the prostatic bed near the bladder neck where the Teflon had been injected. Ultrasound-guided transperineal fine-needle aspiration of the cyst yielded a specimen with numerous birefringent crystalline Teflon particles. Although previous reports have described granulomatous tissue reaction, no multinucleated giant cells were present to suggest granuloma formation. To our knowledge, this is the first reported case of Teflon cyst formation following periurethral Teflon injections. The patient's history, imaging studies, cytopathology, and review of the literature are presented in this report. © 1992 Wiley-Liss, Inc.
Frictional heat generation and seismic radiation in a foam rubber model of earthquakes

Results from a study of stick-slip particle motion at the interface between two stressed foam rubber blocks indicate that normal vibrations and interface separation are an important part of the stick-slip process in foam rubber. The dimension of the dynamic slip pulse is small compared to the dimension of the model (approximately 10 cm vs. 200 cm) consistent with the abrupt-locking slip pulse model ofBrune (1970, 1976), andHeaton (1990). A comparison of frictional heat generation between stable-sliding and stick-slip foam rubber models indicates a linear relation between the temperature increase on the fault surface (for a given distance of slip) and the driving shear force for the stable-sliding model, while for the stick-slip model there is essentially no variation in frictional heat generation with an increase in shear stress. We performed experiments to investigate the ratio of normal motion to shear motion at different levels of normal stress in the stick-slip foam rubber model. Preliminary result indicate that the normal component of the particle motion increases more rapidly with increasing normal stress than the shear component. The phenomenon of interface separation and normal vibrations may thus explain some of the most frustrating problems in earthquake mechanics, e.g., the heat flow paradox, the long-term weakness of major active faults, and anomalousP-wave radiation.
The Physical Nature of the Chemical Bond

The quantum mechanical wave functions of molecules are discussed. An attempt is made to effect a simultaneous regional and physical partitioning of the molecular density, the molecular pair density, and the molecular energy, in such a way that meaningful concepts can be associated with the density and energy fragments thus formed. The origin of chemical binding is interpreted in terms of the concepts formulated in the partitioning process. (T.F.H.)
Influence of Stearidonic Acid on Lipoprotein Secretion and Fatty Acid Composition in HepG2 Cells

The health benefits of ω-3 fatty acids, particularly fish oils, are well known. It is generally recommended to obtain ω-3 fatty acids from fatty fish; however, the possible contaminants in fish products may deter this. Thus, supplements of ω-3 fatty acids from plant-originated lipids may be of interest. Among these, α-linolenic acid (ALA) and stearidonic acid (SDA) have drawn attention. Thus, the purpose of this research was to test the possible conversion of these fatty acids, particularly SDA, to eicosapentaenoic acid (EPA) using a human hepatoma cell line, HepG2 cells. In addition, even though ω-3 fatty acids have been shown to reduce hyperlipidemia, the effects on lipoprotein metabolism are relatively inconsistent. Thus, we also tested ω-3 fatty acids along with SDA on apolipoprotein A and B (apo A and B) secretion from this cell line. The results obtained suggest that both ALA and SDA were converted to EPA and they increased apo B secretion, while having no effect on apo A secretion, similar to the effects of EPA and docosahexaenoic acid. Thus, it may be concluded that SDA can be a possible candidate for use as a precursor for EPA and its effect on lipoproteins was similar to that of EPA. PRACTICAL APPLICATIONS This study suggests the possible use of stearidonic and α-linolenic acids from plant-originated fat as precursors for eicosapentaenoic acid, promoting health benefits as alternatives for fish consumption.
The inhibition of brain protein synthesis following leucine or valine injection can be prevented.

Abstract An intraperitoneal injection of either leucine (1.57 mg/g body wt) or valine (2 mg/g body wt) into newborn mice led to a rapid accumulation of inactive monoribosomes in their brains. In vitro measurements of protein synthesis by the remaining active ribosomes in leucine-treated mice revealed that polypeptide chain elongation was also inhibited. When a mixture of the seven amino acids from the leucine transport system was injected (0.15 mg each amino acid/g body wt) following the valine or leucine treatment, brain monoribosomes did not accumulate and elongation rates in the leucine-treated mice were only slightly altered.
Preliminary Study on the Electrolysis of Titanium Oxysalt

A new method for producing titanium and titanium alloys was studied at this paper. The experiment results indicate that Na2TiO3 could be synthesizing by heating at 450°C using NaOH and TiO2 powders.Metallic titanium was observed in XRD pattern of the electrolytes after experiment by means of constant-current electrolytic Na2TiO3 in a CaCl2-CaF2 melt at 850°C.Thendepending on the electrolytical residua,titanium aluminium alloy could be obtained by calcining with Al powders.
Response of zooplankton to the reduction and elimination of submerged vegetation by grass carp and herbicide in four Florida lakes

Zooplankton populations were monitored monthly for a three year period in four Florida lakes. Each lake received an aquatic vegetation control program using grass carp (Ctenopharyngodon idella Val.) and herbicide, either alone or in combination. All aquatic vegetation was eliminated in the three lakes with grass carp; it was severely reduced and exhibited qualitative shifts in the lake treated with herbicide alone. Total number of recorded zooplankton species was reduced in each subsequent year as vegetation was eliminated, but mean density l−1 increased greatly. The overall trend in all lakes was toward increasing numbers of small filter-feeding herbivores, with a shift from copepod and copepod-cladoceran dominated to rotifer and small cladoceran dominated systems. It is suggested that these changes reflect primary plankton response to fluctuations in habitat, food base, and planktivore pressure resulting from gradual macrophyte alteration. Changes observed indicate apparent increases in eutrophy.
Greatwall and Polo-like Kinase 1 Coordinate to Promote Checkpoint Recovery

Checkpoint recovery upon completion of DNA repair allows the cell to return to normal cell cycle progression and is thus a crucial process that determines cell fate after DNA damage. We previously studied this process in Xenopus egg extracts and established Greatwall (Gwl) as an important regulator. Here we show that preactivated Gwl kinase can promote checkpoint recovery independently of cyclin-dependent kinase 1 (Cdk1) or Plx1 (Xenopus polo-like kinase 1), whereas depletion of Gwl from extracts exhibits no synergy with that of Plx1 in delaying checkpoint recovery, suggesting a distinct but related relationship between Gwl and Plx1. In further revealing their functional relationship, we found mutual dependence for activation of Gwl and Plx1 during checkpoint recovery, as well as their direct association. We characterized the protein association in detail and recapitulated it in vitro with purified proteins, which suggests direct interaction. Interestingly, Gwl interaction with Plx1 and its phosphorylation by Plx1 both increase at the stage of checkpoint recovery. More importantly, Plx1-mediated phosphorylation renders Gwl more efficient in promoting checkpoint recovery, suggesting a functional involvement of such regulation in the recovery process. Finally, we report an indirect regulatory mechanism involving Aurora A that may account for Gwl-dependent regulation of Plx1 during checkpoint recovery. Our results thus reveal novel mechanisms underlying the involvement of Gwl in checkpoint recovery, in particular, its functional relationship with Plx1, a well characterized regulator of checkpoint recovery. Coordinated interplays between Plx1 and Gwl are required for reactivation of these kinases from the G2/M DNA damage checkpoint and efficient checkpoint recovery.
Holography In 15-Foot Bubble Chamber at Fermilab

AbstractThe technique of holography used in a neutrino experiment during 1985 in the 15 -foot cryogenic bubblechamber at Fermilab is presented. In this technique, a modified in -line recording method is used to produceholograms of neutrino interactions. In these high energy interactions short -lived particles are producedwhich decay in times of order of 10 -13 seconds. Holography gives a high resolution over a long depth offield compared to the conventional photographic recording technique. A pulsed ruby laser with anopto- electronic feedback circuit allows the generation of long pulses (a few tens of microseconds). One hundred thousand holograms were recorded during the experiment. An evaluation of the recorded holograms is presented. IntroductionOne of the interests in high energy physics, where the properties and interactions of subatomic particlesare of importance, is to look for short -lived particles with mean lifetime t 10 -13 seconds and mean distancetraveled before decay of a few millimeters. The properties of these rarely produced states (charmed mesons andbaryons, etc.) have been obtained through kinematical analysis of their decay products. Yet this analysis isvery sensitive to the size of the statistical sample. In order to observe these states, a visual detectorcalled the Bubble Chamber can be used. Charged particles traversing a liquid H2 /Ne mix which is in ametastable superheated condition leave a track of tiny bubbles along their paths which can be photographed.The short -lived particles can not be directly observed. Yet they are detected by measuring the deviation fromthe vertex of the extrapolated paths of their decay products. The measurements of this deviation, called theimpact parameter which is a few hundreds of micrometer, necessitate a good spatial resolution. This spatialresolution should be coupled with a long depth of field for big bubble chambers (4 meters in diameter) inorder to cover most of the visible volume of the chamber (14 cubic meters). However, improving the resolutionin conventional photography results in a rapid decrease of the depth of field (resolution a 1 /a; depth of
The NASA Space Radiation Laboratory at Brookhaven National Laboratory: Preparation and delivery of ion beams for space radiation research

Abstract The NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) was commissioned in October 2002 and became operational in July 2003. The NSRL was constructed in collaboration with NASA for the purpose of performing space radiation research as part of the NASA space program. The NSRL can accept a wide variety of ions from BNL’s Collider Accelerator Department (CAD) Booster accelerator. These ion beams are extracted from the accelerator with kinetic energies ranging from 0.05 to 3 GeV/nucleon. Many different beam conditions have been produced for experiments at NSRL. The facilities at BNL and the design of the NSRL facility permit a wide variety of beams to be produced with a great degree of flexibility in the delivery of ion beams to experiments. In this report we will describe the facility and its performance over the eight experimental run periods that have taken place since it became operational. We will also describe the current and future capabilities of the NSRL.
Paleozoic seed fern pollen organs

Paleozoic pollen organs exhibit numerous morphological forms that have been arranged in categories based on their probable organization. Progymnosperm ancestors are characterized by three dimensional branching systems bearing pairs of terminal sporangia. Early Mississippian examples of seed fern fertile branches appear little modified from the progymnosperms. These pteridosperm microsporangia are nonsynangiate and thin walled with longitudinal dehiscence. By Upper Mississippian time all forms show sporangial clustering into large or small groups, with several taxa exhibiting radially symmetrical synangia. In the Lower Pennsylvanian all pollen organs are synangiate and appear to consist of a uniseriate ring of sporangia that either surround a central hollow, or are bilaterally flattened. Sporangial dehiscence in all forms is longitudinal and toward the center of the synangium. In bilateral synangia with no central hollow, the sporangia either separate laterally or effective dehiscence areas are restricted to the free apical portions of the sporangia. Callistophytacean synangia resemble the lyginopterid type, but are abaxial on laminar foliage. This family is thought to have evolved from the lyginopterids during the Early Pennsylvanian. Middle Pennsylvanian medullosan pollen organs are all radial and may be solitary, aggregated into groups, or fused into a large compound synangium. Several pollen organ types are reinterpreted, and the possible evolutionary relationships among the various Paleozoic pollen organ forms are discussed based on synangial organization, patterns of frond branching, and pollen or prepollen morphology.
Statistical inferences for two-dimensional workpiece localisation

In this paper, we study Workpiece Localisation (WL) which can be described as follows. Before machining, a rigid workpiece is fixed to a work table approximately at its nominal location after minimal calibration. With data measured on the fixed workpiece using a Coordinate Measuring Machine (CMM), we aim to determine the Euclidean transformation of the workpiece Computer-Aided Design (CAD) model frame relative to some known world reference frame. Recently the WL problems have been formulated as Least Squares Problems (LSP). Although various algorithms have been proposed to solve the LSP, they involve an iterative process to update the Euclidian transformation and the home points of the measured data. In this paper we propose a new formulation of the WL problems, which can be solved using standard nonlinear least squares method where updating the home points is unnecessary. Additionally, the new formulation enables constructing confidence intervals for the Euclidean transformation parameters.
NAD(P)H: quinone oxidoreductase 1 expression in human bone marrow endothelial cells.

Abstract NAD(P)H:quinone oxidoreductase 1 (NQO1) participates in the detoxification of many environmental quinones and related compounds. Recent studies have suggested that individuals with a polymorphism in NQO1 (NQO1*2), which results in a decrease (heterozygous, NQO1*1/*2) or a total loss (homozygous, NQO1*2/*2) of NQO1, may be at increased risk for the development of leukemias. Previous studies have failed to detect NQO1 in freshly aspirated bone marrow including Ficoll-purified mononuclear cells and purified CD34+ hematopoietic progenitor stem cells. In these studies we examined human bone marrow core biopsies by immunohistochemistry using monoclonal antibodies directed against NQO1. These studies revealed that NQO1 was expressed in human bone marrow but expression of NQO1 was limited to bone marrow endothelium and adipocytes. To confirm the expression of NQO1 in bone marrow endothelial cells we examined an immortalized human bone marrow endothelial cell line (HBMEC-60) for NQO1 protein expression. Immunoblot analysis and an activity assay confirmed the expression of NQO1 in HBMEC-60. These data demonstrate that NQO1 is present in human bone marrow. The increased risk of leukemia associated with a deficit in NQO1 levels due to the NQO1*2 polymorphism may reflect impaired quinone detoxification and an increased susceptibility of endothelial cells in bone marrow to environmental insults.
Chelation-controlled cyclization of β-ketoester-substituted and β-ketoamide-substituted allylsilanes

Abstract The first examples of Lewis acid-catalyzed chelation-controlled cyclization reactions are reported. Titanium tetrachloride-initiated cyclization of β-ketoester and β-ketoamide-substituted allylsilanes proceeds in isolated yields of 65–88%, providing a single diastereomeric product in each case.
Corrosion of aluminium in the aqueous chemical environment of a loss-of-coolant accident at a nuclear power plant

Abstract Aluminium corrosion is a significant concern in the aqueous chemical environment of the reactor containment building following a hypothetical loss-of-coolant accident (LOCA) at a nuclear power plant. Aluminium corrosion may lead to the formation of precipitates that can, in combination with insulation debris, block the recirculation sump screens. This study investigated aluminium corrosion experimentally at both bench and pilot scale under conditions representative of several types of nuclear power plants. Evidence of corrosion was determined using aqueous concentrations measured with inductively-coupled plasma (ICP) spectrometry and surface examinations using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray photoelectron spectrometry (XPS), X-ray fluorescence (XRF), and X-ray diffraction (XRD). Corrosion proceeded slowly at pH near 7, but more rapidly at higher pH when the representative pipe insulation material was fibreglass. However, when calcium silicate pipe insulation was introduced into the system, corrosion became insignificant even at pH values near 10. Experimental evidence indicates that the calcium silicate insulation released a significant amount of silicate to the solution. Silicate formed a passivation layer composed of Al 2 OSiO 4 with a thickness of more than 10 nm, and this layer effectively inhibited corrosion.
Post-extrasystolic potentiation of ischemic myocardium by atrial stimulation

The response of acutely ischemic myocardium to post-extrasystolic potentiation (PESP) was evaluated in 11 mongrel dogs. Mercury-in-silastic length gauges were sutured to the epicardial surface of the left ventricle; left ventricular pressure was determined via an apical large-bore catheter-transducer system and controlled by volume manipulation. The anterior descending coronary artery was then ligated, and single premature atrial contractions were introduced via an external stimulator. Thirty minutes after occlusion, shortening during ejection had decreased an average of 81 +/- 8 per cent, from 1.30 +/- 0.29 to 0.32 +/- 0.05 mm. PESP initially induced a marked restoration toward normal segmental contraction as systolic shortening increased significantly to 1.14 +/- 0.23 mm. Additionally, paradoxic systolic expansion, when present, reverted to a normal pattern of contraction during PESP. Responsiveness to PESP deteriorated progressively with time over 3 hours following occlusion until the muscle became essentially totally unresponsive to this stimulus. It is concluded that a single premature atrial beat may be used to induce PESP and provides an effective stimulus for contractile reserve of acutely dysfunctional ischemic myocardium. Loss of responsiveness to PESP may represent the progression to nonviability following acute ischemia.
Experimental Factors Influencing Variability of the Number of Streptococci Cultured from Tooth Surface

Components of variability that are related to estimating viable tooth surface streptococci were evaluated to assess the effect of real factors and to reduce residual error. Methods of dispersion (mechanical mixing vs ultrasonic agitation), plate count replication, sample site, weighing technic, balance error, and total experimental variability were considered.
Incident-beam effects in electron-stimulated Auger-electron diffraction.

We have examined incident-beam effects in electron-stimulated Auger-electron diffraction (AED) on a cleaved GaAs(110) surface. The results indicate that incident-beam diffraction is significant in an AED experiment, and that the dissipative nature of the incident beam in contributing to the Auger process must be accounted for. We have developed a qualitative model that describes the trend of the polar-angle dependence of the Auger intensity for both the incident and exit beams. In calculating the diffraction features, we used a zeroth-order approximation to simulate the dissipation of the incident beam, which is found to adequately describe the experimental data.
Long-range tropospheric transport of pollution aerosols into the Alaskan Arctic

Abstract Noncrustal vanadium and manganese are used as chemical tracers for pollution-derived aerosols (collected over a period of four years in the near-surface air at Barrow, Alaska), in order to investigate tropospheric long-range transport of anthropogenic pollution from midlatitudes to the Alaskan Arctic. The analysis is based upon subjectively identifying characteristic transport pathway types using daily circumpolar weather maps. The transport occurs when the midlatitudinal and Arctic atmospheric circulations manifest quasi-persistent circulation patterns. Rapid transport of aerosols, on the order of 7–10 days, is dominated by quasi-stationary anticyclones and takes place along their peripheries where pressure gradients are relatively strong. The seasonal variation in concentration of the Arctic pollution-derived aerosol is related to the seasonal variation in the occurrence and position of midlatitude blocking anticyclones, of the Arctic anticyclone and of the Asiatic anticyclone. The positions of...
Detection of bacteria from biological mixtures using immunomagnetic separation combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

A rapid method for identifying specific bacteria from complex biological mixtures using immunomagnetic separation coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been developed. The technique employs commercially available magnetic beads coated with polycolonal antibodies raised against specific bacteria and whole cell analysis by MALDI-MS. A suspension of a bacterial mixture is mixed with the immunomagnetic beads specific for the target microorganism. After a short incubation period (20 mins) the bacteria captured by the beads are washed, resuspended in deionized H2O and directly applied onto a MALDI probe. Liquid suspensions containing bacterial mixtures can be screened within 1 h total analysis time. Positive tests result in the production of a fingerprint mass spectrum primarily consisting of protein biomarkers characteristic of the targeted microorganism. Using this procedure, Salmonella choleraesuis was isolated and detected from standard bacterial mixtures and spiked samples of river water, human urine, and chicken blood. Copyright © 2001 John Wiley & Sons, Ltd.
A Long Terminal Repeat Retrotransposon of Fission Yeast Has Strong Preferences for Specific Sites of Insertion

The successful dispersal of transposons depends on the critical balance between the fitness of the host and the ability of the transposon to insert into the host genome. One method transposons may use to avoid the disruption of coding sequences is to target integration into safe havens. We explored the interaction between the long terminal repeat retrotransposon Tf1 and the genome of the yeast Schizosaccharomyces pombe. Using techniques that were specifically designed to detect integration of Tf1 throughout the genome and to avoid bias in this detection, we generated 51 insertion events. Although 60.2% of the genome of S. pombe is coding sequence, all but one of the insertions occurred in intergenic regions. We also found that Tf1 was significantly more likely to insert into intergenic regions that included polymerase II promoters than into regions between convergent gene pairs. Interestingly, 8 of the 51 insertion sites were isolated multiple times from genetically independent cultures. This result suggests that specific sites in intergenic regions are targeted by Tf1. Perhaps the most surprising observation was that per kilobase of nonrepetitive sequence, Tf1 was significantly more likely to insert into chromosome 3 than into one of the other two chromosomes. This preference was found not to be due to differences in the distribution or composition of intergenic sequences within the three chromosomes.
Practical specification and verification with code contracts

In this tutorial I will introduce CodeContracts, the .NET solution for contract specifications. CodeContracts consist of a language and compiler-agnostic API to express contracts, and of a set of tools to automatically generate the documentation and to perform dynamic and static verification. The CodeContracts API is part of .NET since v4, the tools are available for download on the Visual Studio Gallery. To date, they have been downloaded more than 100,000 times.
Anaerobic threshold detection in patients with congestive heart failure

Anaerobic threshold measurements determined either invasively by analysis of arterial lactate concentration (lactate threshold) or noninvasively by respiratory gas exchange analysis (ventilatory threshold) were compared in patients with chronic congestive heart failure. Sixteen patients performed symptom-limited maximal exercise on a bicycle ergometer using a continuous ramp protocol with measurement of arterial lactate concentration at 1 minute intervals, and continuous breath-by-breath analysis of respiratory gas exchange. A specific lactate threshold point was detected in only 7 patients. These 7 patients had significantly greater peak oxygen uptake than did the 9 in whom no specific lactate threshold point was detected (15.9 +/- 1.0 vs 10.5 +/- 0.5 ml/kg/min; p less than 0.05). Ventilatory threshold significantly correlated with lactate threshold in these 7 patients. In the remaining 9 patients, neither lactate nor ventilatory threshold could be reliably determined with methods used in the present study.
Fidelity studies of the human DNA polymerase alpha. The most conserved region among alpha-like DNA polymerases is responsible for metal-induced infidelity in DNA synthesis

Abstract Mutational studies in the highly conserved region I domain of the human DNA polymerase alpha enzyme demonstrated a change in metal cation-specific catalysis. Here, we extend the investigation to include the fidelity of DNA synthesis by these mutants, studying misinsertion, mispair extension, and the nucleotide analog utilization. The fidelity of region I mutants and wild type human DNA polymerase alpha enzyme were analyzed with either Mg2+ or Mn2+ as the metal activator. Despite the known mutagenic effect of Mn2+ in causing polymerases to misinsert nucleotides and to utilize dideoxynucleotides, we have found that two region I mutants, D1002N and T1003S, which utilize Mn2+ in catalysis more effectively than Mg2+, actually have a 70- and 40-fold higher misinsertion fidelity, respectively, in Mn(2+)-catalyzed reactions than that of the wild type enzyme. The enhanced misinsertion fidelity of these two mutants in Mn(2+)-catalyzed reactions is due to Km discrimination of the incorrect nucleotide where the D1002N and T1003S had a 850- and 62-fold higher Km for insertion of incorrect than correct nucleotide, respectively. In Mg(2+)-catalyzed reactions, all of the region I mutants exhibited similar misinsertion efficiencies as the wild type polymerase. Study of mispair extension showed that in Mn(2+)-catalyzed ractions, the wild type polymerase alpha enzyme readily extended mispair termini. In contrast, the two region I mutants, D1002N and T1003S, were unable to extend the mispaired termini in either Mg(2+)- or Mn(2+)-catalyzed reactions. These results suggest that the side chains of region I amino acids play an essential role in the Mn(2+)-induced infidelity during DNA synthesis by human DNA polymerase alpha. The effects of the metal activator on the utilization of two nucleotide analogs, 3'-azido-3'-deoxythymidine triphosphate and ddCTP, by the region I mutants were also investigated.
Time-varying performance surfaces for adaptive IIR filters: geometric properties and implications for filter stability

We present a new framework for understanding the performance of adaptive IIR filters which enhances the understanding of filter stability during on-line operation. This new understanding arises from examining geometric properties of time-varying performance surfaces which are defined by the data, rather than the standard steady-state error surfaces as defined by statistics of the data. Data-dependent descent directions used in adaptive algorithms to update filter coefficients typically are viewed as functions of gradients defined on fixed performance surfaces, and data is used to approximate these gradients at each iteration. In contrast, we view data-dependent descent directions at each iteration as functions of exact gradients on time-varying performance surfaces. By examining the shape of these time-varying performance surfaces near filter stability boundaries, we are able to identify the origin of on-line stability problems associated with existing adaptive IIR filtering formulations, and suggest corrective measures. Specifically, by using exact z-domain methods, we define time-varying performance surfaces which geometrically enforce filter stability, and maintain the geometric and physical properties of the "true" error surface at each iteration. Development of adaptive algorithms based on this measure is expected to result in adaptive filters having improved stability performance during on-line operation. >
Recognition of emotion in hemifaces presented to the left and right visual fields

Thirty-two right-handed subjects (16 males and 16 females) participated in a choice reaction time experiment replicating two previous studies which demonstrated the superiority of the left hemisphere in rapidly identifying facial emotion as either positive or negative. Slides of hemifaces split along the vertical axis, showing either positive (happiness, surprise) or negative (anger, disgust, or sadness) affect were presented tachistoscopically to either the left or right visual field. A 2×2×2 mixed ANOVA revealed main effects for visual field and type of affect. In contrast to earlier studies which presented full face stimuli, presentation of hemifaces produced a strong left visual field advantage and, as expected, positive faces produced faster reaction times than negative faces.
Affairs of the Heart: Qualities of Adolescent Romantic Relationships and Sexual Behavior

We know more about parent and peer influences than about the ways in which specific qualities of adolescent romantic relationships may influence sexual decision-making. Using data from the Toledo Adolescent Relationships Study, we focus on communication processes and emotional feelings, as well as more basic contours of adolescent romantic relationships, including power and influence dynamics. Controlling for traditional predictors and duration of the relationship, results suggest that subjectively experienced relationship qualities matter for understanding teens' sexual behavior choices. Further, findings indicate a similar effect of most relationship qualities on male and female reports of sexual behavior. However, influence and power dynamics within the relationship were not related to the likelihood that boys reported sexual intercourse in a focal relationship. In contrast, girls who perceived a more favorable power balance were less likely to report sexual intercourse than their female counterparts who perceived a less favorable power balance. Recognizing that the results capture reciprocal influence processes, longitudinal and qualitative data are used to further explore the complex nature of these associations.