cssi/SciSciGPT-SciSciNet huggingface dataset:
Diffusion MR Imaging: Basic Principles

From their origin as simple techniques primarily used for detecting acute cerebral ischemia, diffusion MR imaging techniques have rapidly evolved into a versatile set of tools that provide the only noninvasive means of characterizing brain microstructure and connectivity, becoming a mainstay of both clinical and investigational brain MR imaging. In this article, the basic principles required for understanding diffusion MR imaging techniques are reviewed with clinical neuroradiologists in mind.
Effects of pseudostuttering on normal speaker's self-ratings of beauty

Abstract Forty-three undergraduate and 12 graduate students provided numerical evaluations of their own outer beauty and inner beauty, both in class, and immediately following a pseudostuttering assignment. Both groups had significant downshifts in both parameters of beauty. The undergraduate students had greater downshifts in both areas than did the graduate students. It was concluded that, (1) pseudostuttering assignments represent a viable instrument for allowing student clinicians to experience negative feelings as a result of stuttering, and (2) graduate students manifested greater stability in their self-evaluations than did the undergraduate students.
Book Review: The Crack Revolution

Crackhouse: Notes from the End of the Line, by Terry Williams. Reading, Massachusetts: Addison-Wesley, 1992, 156 pp., $17.95 U.S., $22.95 Canadian
Review of the cytogenetic changes in acute megakaryoblastic leukemia: one disease or several?

Abstract The karyotypes of 116 cases of acute megakaryoblastic leukemia (AMKL) were reviewed, including 43 pediatric patients with Down syndrome (DS) and 73 non-DS patients. DS patients with AMKL often had a history of transient leukemia or myelodysplasia with an early age of onset of AMKL (median 23 months). In these patients, the frequency of additional cytogenetic change (numerical or structural) was low, with 10 of the 43 DS patients showing no additional cytogenetic change. A second group of patients had t(1;22)(p13;q13) or other cytogenetic abnormality involving 22q13. These patients had no history of transient leukemia but showed very early onset of AMKL. In this group of patients, marked organomegaly was noted; these patients also showed few specific additional cytogenetic changes. The remaining AMKL patients had a median age of 30 years with much more frequent cytogenetic changes, including rearrangement of 3q21 and 3q26–27, trisomy 21, and other specific changes. Based on the karyotype and clinical data, we hypothesize that AMKL may represent at least three separate disease entities with different genetic alterations giving rise to similar, but not identical, disorders. Subclassification of AMKL on the basis of the cytogenetic changes in the leukemic cells appears to be justified.
Fibrous astrocytes in senile dementia of the alzheimer type

Fibrous astrocytes were stained by the Sternberger (peroxidase-antiperoxidase) method, using paraffin sections of mid-frontal cerebral cortex of patients with senile dementia and of normals of similar age. The populations of fibrous astrocytes were similar in the molecular layer, but were widely divergent in layers II through VI. Here the mean count of fibrous astrocytes in senile dementia of the Alzheimer type was more than four times that of the normal aged cortex.
TRANSCATHETER AORTIC VALVE REPLACEMENT VERSUS SURGICAL AORTIC VALVE REPLACEMENT IN A LOW TO INTERMEDIATE RISK POPULATION

The results of studies comparing the clinical efficacy of transcatheter aortic valve replacement (TAVR) versus surgical aortic valve replacement (AVR) in low to intermediate risk patients are not yet available. We compared outcomes in patients undergoing TAVR with low Society for Thoracic Surgery (
Influence of association cortex on penicillin discharges in the primary visual cortex

Abstract The influence of visual association cortex on the pattern of neuronal activity in the lateral geniculate body, during penicillin-induced discharges in visual cortex, was studied. In a majority of those geniculate cells which exhibited a pre-penicillin discharge increment in activity, that increment was abolished or significantly reduced during focal hypothermia of the visual association cortex. The frequency of penicillin discharges in visual cortex was, in most cases, reduced during cooling of association cortex. These findings are briefly discussed in terms of corticothalamic interaction.
The immunosuppressant FTY720 is phosphorylated by sphingosine kinase type 2

The potent immunosuppressive drug FTY720, a sphingosine analog, induces redistribution of lymphocytes from circulation to secondary lymphoid tissues. FTY720 is phosphorylated in vivo and functions as an agonist for four G-protein-coupled sphingosine-1-phosphate receptors. The identity of the kinase that phosphorylates FTY720 is still not known. Here we report that although both sphingosine kinase type 1 (SphK1) and type 2 (SphK2) can phosphorylate FTY720 with low efficiency, SphK2 is much more effective than SphK1. FTY720 inhibited phosphorylation of sphingosine catalyzed by SphK2 to a greater extent than it inhibits SphK1. Thus, SphK2 may be the relevant enzyme that is responsible for in vivo phosphorylation of FTY720.
Factors Influencing the Appropriateness of Restorative Dental Treatment: an Epidemiologic Perspective

Objectives An epidemiology analysis was performed to identify patient and dentist factors influencing over- and undertreatment of restorative services in a sample of insured adults. Methods At baseline, 681 Washington State employees and their spouses, aged 20 to 34 years and residing in the Olympia or Pullman areas, were interviewed by telephone. Oral assessments were conducted to measure personal characteristics, oral disease, and restoration quality. Adults were followed for two years to measure use of restorative services from dental insurance claims. Each adult's baseline and claims data were linked with provider and practice variables collected from the dentist who provided treatment. Results For overtreatment, 39 percent of adults received one or more replacement restorations in nondecayed teeth with satisfactory fillings at baseline, while 18 percent of adults had one or more restorations placed in teeth with no decay and fillings. An adult's probability of overtreatment was higher if the adult had more fillings at baseline, or if an adult's dentist was younger, had a busy practice, advertised, charged higher fees, had less continuing education, or had a solo practice. For undertreatment, about 16 percent of adults either received no replacement restorations in teeth with unsatisfactory fillings at baseline, or had decayed teeth at baseline that were not filled or crowned. An adult's probability of undertreatment was higher if an adult had less decayed or more missing surfaces at baseline, or if an adult's dentist believed in sharing information with patients, had a busy practice, or reported not placing fillings when radiographic evidence of new caries was present. Conclusions A minority of adults aged 20 to 34 experienced potential over- or undertreatment of restorative services, which are influenced by both patient and dentist factors.
ZFNGenome: a comprehensive resource for locating zinc finger nuclease target sites in model organisms

Zinc Finger Nucleases (ZFNs) have tremendous potential as tools to facilitate genomic modifications, such as precise gene knockouts or gene replacements by homologous recombination. ZFNs can be used to advance both basic research and clinical applications, including gene therapy. Recently, the ability to engineer ZFNs that target any desired genomic DNA sequence with high fidelity has improved significantly with the introduction of rapid, robust, and publicly available techniques for ZFN design such as the Oligomerized Pool ENgineering (OPEN) method. The motivation for this study is to make resources for genome modifications using OPEN-generated ZFNs more accessible to researchers by creating a user-friendly interface that identifies and provides quality scores for all potential ZFN target sites in the complete genomes of several model organisms. ZFNGenome is a GBrowse-based tool for identifying and visualizing potential target sites for OPEN-generated ZFNs. ZFNGenome currently includes a total of more than 11.6 million potential ZFN target sites, mapped within the fully sequenced genomes of seven model organisms; S. cerevisiae, C. reinhardtii, A. thaliana, D. melanogaster, D. rerio, C. elegans, and H. sapiens and can be visualized within the flexible GBrowse environment. Additional model organisms will be included in future updates. ZFNGenome provides information about each potential ZFN target site, including its chromosomal location and position relative to transcription initiation site(s). Users can query ZFNGenome using several different criteria (e.g., gene ID, transcript ID, target site sequence). Tracks in ZFNGenome also provide "uniqueness" and ZiFOpT (Zi nc F inger OP EN T argeter) "confidence" scores that estimate the likelihood that a chosen ZFN target site will function in vivo. ZFNGenome is dynamically linked to ZiFDB, allowing users access to all available information about zinc finger reagents, such as the effectiveness of a given ZFN in creating double-stranded breaks. ZFNGenome provides a user-friendly interface that allows researchers to access resources and information regarding genomic target sites for engineered ZFNs in seven model organisms. This genome-wide database of potential ZFN target sites should greatly facilitate the utilization of ZFNs in both basic and clinical research. ZFNGenome is freely available at: http://bindr.gdcb.iastate.edu/ZFNGenome or at the Zinc Finger Consortium website: http://www.zincfingers.org/ .
Chronic Hemospermia; Its Origin and Treatment with Estrogen1

THE PROBLEM of the origin of the blood in chronic hemospermia was attacked by a chemical study of the ejaculate collected in serial fractions, the three glass test, and it was found that the hemorrhage arises from the vesicular apparatus. On theoretical grounds it was appropriate to test the effect of estrogen as a therapeutic agent. Six patients were treated, and in five the hemorrhage ceased. Blood in the semen is caused by many agents. It is useful to differentiate between hemospermia of brief duration and the more chronic condition. Acute hemospermia is observed not infrequently and the causes are often obvious; as a few common examples we cite acute prostatitis, ejaculation before complete healing following prostatic resection, and ejaculation following trauma. These episodes of bleeding are temporary in the majority of cases and will not be considered further in this paper. Of entirely different etiology and course is chronic hemospermia.
High-performance liquid chromatographic mapping and structural characterization of neurophysin isoforms

Abstract Both ion-exchange and reverse-phase HPLC protocols for micromapping of neurophysins have been examined and the structural relationships among the major isoforms identified in the maps have been characterized. Reverse-phase HPLC was found to be especially useful for obtaining fingerprints of the isoforms within each of the two major families of neurophysins, I (oxytocin-related) and II (vasopressin-related), for both bovine and human neurophysins from posterior pituitary sources. From fractionation of the bovine proteins on octylsilyl columns, at least four neurophysins I were identified, one of which corresponds to the intact sequence of 93 residues and three of which vary from the parent by various degrees of carboxyl-terminal truncation. For bovine neurophysin II, two isoforms were identified in the reverse-phase HPLC maps, both of 95 residues, which vary from one another by the residue, either Ile or Val, at position 89. Isoforms were also detected for human neurophysins, including a carboxyl-terminal truncated form of human neurophysin II. All of the major neurophysin isoforms and several of the minor forms were shown to be functionally active as expressed by their binding to peptide ligand affinity matrices. Reverse-phase HPLC mapping on the octylsilyl matrix allowed neurophysin fingerprinting of crude tissue extracts by providing a narrow “window” within which the neurophysins elute but many other polypeptides expected to be present are excluded. The reverse phase HPLC method provides a useful way to obtain isolated neurophysin isoforms for physicochemical characterizations now usually carried out with mixtures of isoforms obtained by ion-exchange chromatography. The method also has characteristics amenable both for high-sensitivity fingerprinting of neurophysin isoforms, from different species and anatomical sources, and as a prelude to microstructural and -functional characterization of the isoforms so isolated.
The Quiet Clam Is Quite Calm: Transposed-Letter Neighborhood Effects on Eye Movements during Reading.

In responses time tasks, inhibitory neighborhood effects have been found for word pairs that differ in a transposition of two adjacent letters (e.g., clam/calm). Here, the author describes two eye-tracking experiments conducted to explore transposed-letter (TL) neighborhood effects within the context of normal silent reading. In Experiment 1, sentences contained a target word that either has a TL neighbor (e.g., angel, which has the TL neighbor angle) or does not (e.g., alien). In Experiment 2, the context was manipulated to examine whether semantic constraints attenuate neighborhood effects. Readers took longer to process words that have a TL neighbor than control words but only when either member of the TL pair was likely. Furthermore, this interference effect occurred very late in processing and was not affected by relative word frequency. These interference effects can be explained either by the spreading of activation from the target word to its TL neighbor or by the misidentification of target words for their TL neighbors. Implications for models of orthographic input coding and models of eye-movement control are discussed.
Dynamics and Stability of Collective Action Norms

A set of computational experiments investigated a model of formal and informal control, showing how selective incentives to work for the collective good may paradoxically lead to enforcement of antisocial norms that oppose the collective good. In these conditions, the widely cited effects of selective incentives, group cohesiveness, and second-order free riding on collective action may be inverted. Mathematical analysis provides some certain bounds on the model's behavior and relaxes several restrictive assumptions used in the simulation research. This complementary view deepens our understanding of second order social control as a solution to problems of collective action.
Computational modeling of dendrites

Computational methods have been part of neuroscience for many years. For example, models developed with these methods have provided a theory that helps explain the action potential. More recently, as experimental patch-electrode techniques have revealed new biophysics related to dendritic function and synaptic integration, computational models of dendrites have been developed to explain and further illuminate these results, and to predict possible additional behavior. Here, a collection of computational models of dendrites is reviewed. The goal is to help explain how such computational techniques work, some of their limitations, and what one can hope to learn about dendrites by modeling them.
Growth-factor enhancement of compromised gut function following massive small-bowel resection

Our laboratory has shown that epidermal growth factor (EGF) and hepatocyte growth factor (HGF) can improve the function of normal rat small intestine. This study was designed to evaluate the role of these growth factors on the residual small intestine following massive (80%) small bowel resection. Our data demonstrate that EGF and HGF can enhance intestinal substrate absorption and mucosal mass beyond that which occurs with intestinal adaptation. These growth factors may be beneficial in the management of children with short bowel syndrome.
Signal integration through blending, bolstering and bifurcating of intracellular information

A cell's response to its environment is often determined by signaling through the actions of enzyme cascades. The ability to organize these enzymes into multiprotein complexes allows for a high degree of fidelity, efficiency and spatial precision in signaling responses.
Organizational climate and teacher autonomy: implications for educational reform

Shows how educational reform has been a persistent concern in the USA for decades. Recent reform initiatives have focused on teacher autonomy and teacher participation in school‐based decision making. Private sector and school research identify the importance of worker/teacher autonomy. This autonomy leads to a sense of ownership and empowerment where workers aim to grow within their profession and to seek increased responsibility. Believes real education reform must provide teachers with decision‐making responsibility and autonomy in educational matters including choice with respect to professional development. This can only be accomplished in a supportive and nurturing organization.
LSF and NTF-1 Share a Conserved DNA Recognition Motif yet Require Different Oligomerization States to Form a Stable Protein-DNA Complex

The mammalian transcription factor LSF (also known as CP2 and LBP-1c) binds as a homo-oligomer to directly repeated elements in viral and cellular promoters. LSF and theDrosophila transcription factor NTF-1 (also known as Elf-1 and Grainyhead) share a similar DNA binding region, which is unlike any established DNA binding motifs. However, we demonstrate that dimeric NTF-1 can bind an LSF half-site, whereas LSF cannot. To characterize further the DNA binding and oligomerization characteristics of LSF, truncation mutants were used to demonstrate that between 234 and 320 amino acids of LSF are required for high affinity DNA binding. Mixing of a truncation mutant with full-length LSF in a DNA binding assay established that the form of LSF that binds DNA is larger than a dimer. Unexpectedly, one C-terminal deletion derivative, partially defective in oligomerization properties, could occupy odd numbers of adjacent, tandem LSF half-sites, unlike full-length LSF. The numbers of DNA-protein complexes formed on multiple half-sites with this mutant indicated that LSF binds DNA as a tetramer, although cross-linking experiments confirmed a previous report concluding that LSF is primarily dimeric in solution. The DNA binding and oligomerization properties of LSF support models depicting novel mechanisms to prevent continual, adjacent binding by a protein that recognizes directly repeated DNA sequences.
Phosphate basicity and nucleophilicity loss upon constraint: the role of the alkoxy oxygens.

Abstract Structural evidence is cited which suggests that the POC angle is more flexible than the OPO angle when phosphate ester alkoxy groups are constrained into rings. In hybridization terms, the tendency for the POC angle to decrease from ca. 120° in acyclic systems to probably less than 115° in O = P(O)(OCH 2 ) 2 CH is consistent with the notion that an sp 2 alkoxy oxygen is less capable of pi bonding to phosphorus and consequently the negative charge on the phosphorus and hence also on the phosphoryl oxygen is decreased. The difference in orbital configurations in acyclic phosphates and in monocyclic and bicyclic analogues has an effect which is seen to re-enforce the hybridization argument. These simple considerations are shown to account for the bulk of the evidence demonstrating that phosphate ester nucleophilicity and basicity decreases on constraint of these systems. The “hinge effect” described above for oxygen in phosphates also appears to play a role in varying the basicities of phosphites and also possibly in the acidity changes in certain borate derivates on constraint. Nitrogen apparently also displays a “hinge effect” in several amino phosphine systems.
Separation of components of cellulolytic systems by paper chromatography

Abstract It has been demonstrated by paper chromatography that filtrates of cellulolytic organisms contain up to three cellulolytic (Cx) components, depending on the species and on the conditions of growth. The cellulolytic components may also be separated by differential adsorption on cellulose and kaolin. The several components may represent multiple enzymes, or may be due to interactions of a single enzyme with other elements in the system.
Advances in the Boundary Integral Equation Method in Subsurface Flow

: This paper explores some of the advances of the boundary element method, as applied to ground-water problems, during the last five years. Although the method is still somewhat limited compared to solution by finite elements, the range of solutions has increased considerably. Diffusion and advection-diffusion solutions are done efficiently. These include the incorporation of inhomogeneity, anisotropy, and nonlinear diffusion. The difficult problem of stream-aquifer interaction is an important application as it is much easier to follow a free surface with its multiple configurations. The application must be able to cycle between ground-water connection and disconnection with the stream and include seepage surfaces. Flow in fractured media is a natural application where the flow in fractures can usually be treated without a computational exception in spite of extremely high aspect ratios. The case of seawater intrusion forms a type of free surface problem and thus is a case for which the method has special advantages. For these and other applications the boundary element method provides an inexpensive technique for calculation where the data preparation and setup time is minimal. In most of these cases, programs can and have been written on microcomputers.
I-131 SPECT activity recovery coefficients with implicit or triple-energy-window scatter correction

Abstract We define a total-activity recovery coefficient, TARC, as the activity within a volume of interest applied to a set of images from single photon emission computed tomography (SPECT) divided by the true activity in that volume. Because of finite camera resolution, recovery-coefficient values are expected to be less than 1 for small objects. In this report, the TARC is measured as a function of volume, background activity and image-acquisition radius of rotation. A set of hollow spheres which vary in volume are filled with a solution of I-131 in water, and placed within a water-filled cylinder having an elliptical cross section. Tomographic-imaging measurements are carried out for two systems. The first utilizes an implicit scatter correction and the second triple-energy-window correction. Both systems employ a reconstructed-counts-to-activity conversion factor which varies with a measured background parameter and with the radius of rotation. Sphere and cylinder outlines are drawn on a CT scan and transferred to the SPECT scan via a 3-D image fusion. As expected, the inverse of the TARC increases as the sphere volume decreases. With implicit scatter correction, the TARC has no systematic dependence on either radius of rotation or background. With triple-energy-window scatter correction, there is an increase in 1/TARC when the radius of rotation is increased by 5 cm. This increase ranges from 9% to 25% depending on volume. For all conditions, 1/TARC is fit to a power-law equation as a function of sphere volume. The use of the resultant equations to correct a measured activity for a small volume is outlined. Accuracy of the present relationships for target shapes which are not spherical is not addressed.
Fabrication and Plastic Behavior of Single‐Crysta MgO‐NiO and MgO‐MnO Solid‐Solution Alloys

A method of producing solid-solution MgO-NiO and MgO-MnO single crystals is presented. The compressive yield strength of MgO increased nearly fourfold when small amounts of either NiO or MnO were in solid solution in MgO. The cleavage and slip behavior of these alloy crystals was identical to that of MgO.
Hsp90 and environmental impacts on epigenetic states: a model for the trans-generational effects of diethylstibesterol on uterine development and cancer

Hsp90 is a chaperone for over 100 'client proteins' in the cell, most of which are involved in signaling pathways. For example, Hsp90 maintains several nuclear hormone receptors, such as the estrogen receptor (ER), as agonist-receptive monomers in the cytoplasm. In the presence of agonist, Hsp90 dissociates and the receptors dimerize, enter the nucleus and ultimately activate transcription of the target genes. Increasing evidence suggests that Hsp90 also has a role in modifying the chromatin conformation of many genes. For example, Hsp90 has recently been shown to increase the activity of the histone H3 lysine-4 methyltransferase SMYD3, which activates the chromatin of target genes. Further evidence for chromatin-remodeling functions is that Hsp90 acts as a capacitor for morphological evolution by masking epigenetic variation. Release of the capacitor function of Hsp90, such as by environmental stress or by drugs that inhibit the ATP-binding activity of Hsp90, exposes previously hidden morphological phenotypes in the next generation and for several generations thereafter. The chromatin-modifying phenotypes of Hsp90 have striking similarities to the trans-generational effects of the ER agonist diethylstilbesterol (DES). Prenatal and perinatal exposure to DES increases the predisposition to uterine developmental abnormalities and cancer in the daughters and granddaughters of exposed pregnant mice. In this review, we propose that trans-generational epigenetic phenomena involving Hsp90 and DES are related and that chromatin-mediated WNT signaling modifications are required. This model suggests that inhibitors of Hsp90, WNT signaling and chromatin-remodeling enzymes might function as anticancer agents by interfering with epigenetic reprogramming and canalization in cancer stem cells.
The effects of river floodwaters on floodplain wetland water quality and diatom assemblages

We investigated the effects of river floodpulses on the water chemistry and diatom assemblages in a floodplain wetland. During the two year study period (November 2003-September 2005), the river and wetland exhibited three periods of surface hydrologic connectivity. The impacts of flooding depended on flood magnitude and duration. Both the long/high magnitude and short/high magnitude floods thoroughly mixed river and wetland waters, with conductivity, total nitrogen, and total phosphorus in the wetland decreasing to levels similar to the river. In contrast, the short/low magnitude flood did not mix water chemistry. Wetland conductivity, total nitrogen, and total phosphorus remained elevated. Changes in algal biomass followed changes in water chemistry with the high magnitude floods producing conditions unfavorable for algal growth. Algal biomass decreased in the wetland coinciding with the two high magnitude floods. Increases in algal biomass coincided with the short/low magnitude flood. Wetland and river water column diatom assemblages were dominated by periphytic taxa. The diatom assemblage in the river and wetland were distinct, except during the short/high magnitude flood. During this period, floodwaters brought diatoms into the wetland and both systems were dominated by planktonic centric taxa. Similar diatom taxa were observed in the wetland water column assemblage and the assemblage collected in settling chambers, although their relative abundances varied. Shifts in the settling diatom assemblage coincided with periods of flooding, indicating that river floodwaters leave a discernable signal within this assemblage. Our findings indicate that caution should be exercised when using diatom-based bioassessment in frequently flooded wetlands as the wetland diatom assemblage is influenced by river floodwaters and changes may depend on the duration and magnitude of flooding.
Impact of Resident Involvement on Orthopaedic Surgery Outcomes: An Analysis of 30,628 Patients from the American College of Surgeons National Surgical Quality Improvement Program Database.

Background: Operative procedural training is a key component of orthopaedic surgery residency. The influence of intraoperative resident participation on the outcomes of surgery has not been studied extensively using large, population-based databases. Methods: We identified 30,628 patients who underwent orthopaedic procedures from the 2011 American College of Surgeons National Surgical Quality Improvement Program. Outcomes as measured by perioperative complications, readmission rates, and mortality within thirty days were compared for cases with and without intraoperative resident involvement. Results: Logistic regression with propensity score analysis revealed that intraoperative resident participation was associated with decreased rates of overall complications (odds ratio, 0.717 [95% confidence interval, 0.657 to 0.782]), medical complications (odds ratio, 0.723 [95% confidence interval, 0.661 to 0.790]), and mortality (odds ratio, 0.638 [95% confidence interval, 0.427 to 0.951]). Resident presence in the operating room was not predictive of wound complications (odds ratio, 0.831 [95% confidence interval, 0.656 to 1.053]), readmission (odds ratio, 0.962 [95% confidence interval, 0.830 to 1.116]), or reoperation (odds ratio, 0.938 [95% confidence interval, 0.758 to 1.161]). A second analysis by propensity score stratification into quintiles grouped by similar probability of intraoperative resident presence showed resident involvement to correlate with decreased rates of overall and medical complications in three quintiles, but increased rates of overall and medical complications in one quintile. All other outcomes were equivalent across quintiles. Conclusions: Orthopaedic resident involvement during surgical procedures is associated with lower risk of perioperative complications and mortality in the National Surgical Quality Improvement Program database. The results support resident participation in the operative care of orthopaedic patients. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
One Dimensional Locally Connected S-spaces

Abstract We construct, assuming Jensen's principle ⋄, a one-dimensional locally connected hereditarily separable continuum without convergent sequences.
Novel concept prototype of low‐power‐consumption electrically heatable catalyst

Electrically heated catalyst devices (EHCs) are important for treating exhaust gases in the 20 to 120 s warmup period after a cold start when about 70% of the total hydrocarbon (HC) and carbon monoxide (CO) emissions from a modern gasoline powered vehicle are released. Although known for several years, EHCs have not been deployed because these devices are cost- and energy-intensive. An alternate EHC prototype proposed here is based on our reasoning that only the platinum group metals and the molecules undergoing oxidation need to be at light-off temperatures and it is not necessary to waste energy to heat the whole catalyst. The concept prototype, fabricated on a glass coupon, resistively heats the fluorine doped tin oxide film beneath the washcoat to bring a palladium-titania washcoat to the CO and HC light-off temperatures. The electrically powered concept prototype showed light-off temperatures of 250°C and 260°C for CO and HC, respectively, in laboratory tests with simulated exhaust gases at 25°C. A device based on this concept is estimated to attain the 1-kW target power consumption required for the deployment of the EHC.
BRCA1 interacts with dominant negative SWI/SNF enzymes without affecting homologous recombination or radiation-induced gene activation of p21 or Mdm2

BRCA1 is a tumor suppressor gene linked to familial breast and ovarian cancer. The BRCA1 protein has been implicated in a diverse set of cellular functions, including activation of gene expression by the p53 tumor suppressor and control of homologous recombination (HR) during DNA repair. Prior reports have demonstrated that BRCA1 can exist in cells in a complex with the BRG1-based SWI/SNF ATP-dependent chromatin remodeling enzymes and that SWI/SNF components contribute to p53-mediated gene activation. To investigate the link between SWI/SNF function and BRCA1 mediated effects on p53-mediated gene activation and on mechanisms of homologous recombination, we have utilized mammalian cells that inducibly express an ATPase-deficient, dominant negative SWI/SNF enzymes. Mutant SWI/SNF ATPases retain the ability to interact with BRCA1 in cells. We report that expression of dominant negative SWI/SNF enzymes does not affect p53-mediated induction of the p21 cyclin dependent kinase inhibitor or the Mdm2 E3 ubiquitin ligase that regulates p53 in cells exposed to UV or gamma irradiation. Similarly, integration of a reporter that monitors homologous recombination by gene conversion into these cells demonstrated no change in the recombination rate in the absence of functional SWI/SNF enzyme. We conclude that the SWI/SNF chromatin remodeling enzymes may contribute to but are not required for these processes. © 2004 Wiley-Liss, Inc.
A research C# compiler

C# is the new flagship language in the Microsoft .NET platform. C# is an attractive vehicle for language design research not only because it shares many characteristics with Java, the current language of choice for such research, but also because it is likely to see wide use. Language research needs a large investment in infrastructure, even for relatively small studies. This paper describes a new C# compiler designed specifically to provide that infrastructure. The overall design is deceptively simple. The parser is generated automatically from a possibly ambiguous grammar, accepts C# source, perhaps with new features, and produces an abstract syntax tree, or AST.Subsequent phases--dubbed visitors--traverse the AST, perhaps modifying it, annotating it or emitting output, and pass it along to the next visitor. Visitors are specified entirely at compilation time and are loaded dynamically as needed. There is no fixed set of visitors, and visitors are completely unconstrained. Some visitors perform traditional compilation phases, but the more interesting ones do code analysis, emit non-traditional data such as XML, and display data structures for debugging. Indeed, most usage to date has heen for tools, not for language design experiments. Such experiments use source-to-source transformations or extend existing visitors to handle new language features. These approaches are illustrated by adding a statement that switches on a type instead of a value, which can be implemented in a few hundred lines. The compiler also exemplifies the value of dynamic loading and of type reflection.
Chemical rescue of protein tyrosine phosphatase activity

We report that the activity of a rationally engineered protein tyrosine phosphatase (PTP) mutant can be fully rescued by the addition of the biarsenical fluorescein derivative FlAsH, a compound that does not affect the activity of wild-type PTPs.
The effect of speed loop bandwidths and line-speed on system natural frequencies in multi-span strip processing systems

Strip processing systems (SPSs) are composed of multiple tension zones. These zones are separated by driven rolls such as bridles whose speed is regulated by a closed loop controller. Given that the typical tension regulator regulates tension by trimming the reference to a closed speed loop controller, the designer of the tension regulator cannot ignore the effects of closing the speed loop, and line speed, on the strip processing system natural frequencies. These natural frequencies are typically computed as the eigenvalues of an equivalent translational cascaded spring-mass system. This paper discusses these effects.
Anxiety: its role in the history of psychiatric epidemiology

Background The role played by anxiety in the history of psychiatric epidemiology has not been well recognized. Such lack of understanding retarded the incremental growth of psychiatric research in general populations. It seems useful to look back on this history while deliberations are being carried out about how anxiety will be presented in DSM-V. Method Drawing on the literature and our own research, we examined work that was carried out during and after the Second World War by a Research Branch of the United States War Department, by the Stirling County Study, and by the Midtown Manhattan Study. The differential influences of Meyerian psychobiology and Freudian psychoanalysis are noted. Results The instruments developed in the early epidemiologic endeavors used questions about nervousness, palpitations, sweating, trembling, shortness of breath, upset stomach, etc. These symptoms are important features of what the clinical literature called 'manifest', 'free-floating' or 'chronic anxiety'. A useful descriptive name is 'autonomic anxiety'. Conclusions Although not focusing on specific circumstances as in Panic and Phobic disorders, a non-specific form of autonomic anxiety is a common, disabling and usually chronic disorder that received empirical verification in studies of several community populations. It is suggested that two types of general anxiety may need to be recognized, one dominated by excessive worry and feelings of stress, as in the current DSM-IV definition of Generalized Anxiety Disorder (GAD), and another emphasizing frequent unexplainable autonomic fearfulness, as in the early epidemiologic studies.
Long-Term Psychological Consequences in Women of Witnessing Parental Physical Conflict and Experiencing Abuse in Childhood

Exposure to parental domestic violence in childhood is associated with long-term psychological maladjustment. Although previous studies controlled for childhood physical abuse, it is unclear how the coexisting risk factors of sexual abuse and parental substance use contribute to psychopathology. Questionnaires assessing childhood risk factors and current symptoms were completed by 131 college women. We compared a nonwitness control group with two groups exposed to moderate or to severe marital violence. Witnesses of marital violence experienced more sexual and physical abuse and more parental substance use in childhood than did nonwitnesses and there was more violence in their own dating relationships, even after controlling for other risk factors. Depression, trauma symptoms, antisocial behaviors, and suicidal behaviors were related to childhood experiences of sexual and physical abuse. The need for future research to examine multiple childhood stressors simultaneously is discussed.
Leadership Reconsidered as Historical Subject: Sketches from the Cold War to Post-9/11:

In this essay, we seek to further an understanding of leadership as the evolution of perspectives embedded within a wider historical frame. It is our contention that recovering the historical, econ...
Molecular analysis of an ATP-dependent anion pump

The plasmid-borne arsenical resistance operon encodes an ATP-driven oxyanion pump for the extrusion of the oxyanions arsenite, antimonite and arsenate from bacterial cells. The catalytic component of the pump, the 63 kDa ArsA protein, hydrolyses ATP in the presence of its anionic substrate antimonite (SbO $^-_2$ ). The ATP analogue $5'$ -p-fluorosulphonylbenzoyladenosine was used to modify the ATP binding site(s) of the ArsA protein. From sequence analysis there are two potential nucleotide binding sites. Mutations were introduced into the N-terminal site. Purified mutant proteins were catalytically inactive and incapable of binding nucleotides. Conformational changes produced upon binding of substrates to the ArsA protein were investigated by measuring the effects of substrates on trypsin inactivation. The hydrophobic 45.5 kDa ArsB protein forms the membrane anchor for the ArsA protein. The presence of the ArsA protein on purified inner membrane can be detected immunologically. In the absence of the arsB gene no ArsA is found on the membrane. Synthesis of the ArsB protein is limiting for formation of the pump. Analysis of mRNA structure suggests a potential translational block to synthesis of the ArsB protein. Northern analysis of the ars message demonstrates rapid degradation of the mRNA in the arsB region.
Nature of KaiB-KaiC binding in the cyanobacterial circadian oscillator

In the cyanobacteria Synechococcus elongatus and Thermosynechococcus elongatus, the KaiA, KaiB and KaiC proteins in the presence of ATP generate a post-translational oscillator (PTO) that can be reconstituted in vitro. KaiC is the result of a gene duplication and resembles a double doughnut with N-terminal CI and C-terminal CII hexameric rings. Six ATPs are bound between subunits in both the CI and CII ring. CI harbors ATPase activity, and CII catalyzes phosphorylation and dephosphorylation at T432 and S431 with a ca. 24-h period. KaiA stimulates KaiC phosphorylation, and KaiB promotes KaiC subunit exchange and sequesters KaiA on the KaiB-KaiC interface in the final stage of the clock cycle. Studies of the PTO protein-protein interactions are convergent in terms of KaiA binding to CII but have led to two opposing models of the KaiB-KaiC interaction. Electron microscopy (EM) and small angle X-ray scattering (SAXS), together with native PAGE using full-length proteins and separate CI and CII rings, are consistent with binding of KaiB to CII. Conversely, NMR together with gel filtration chromatography and denatured PAGE using monomeric CI and CII domains support KaiB binding to CI. To resolve the existing controversy, we studied complexes between KaiB and gold-labeled, full-length KaiC with negative stain EM. The EM data clearly demonstrate that KaiB contacts the CII ring. Together with the outcomes of previous analyses, our work establishes that only CII participates in interactions with KaiA and KaiB as well as with the His kinase SasA involved in the clock output pathway.
The molecular bases of plant resistance and defense responses to aphid feeding: current status

Plant genes participating in the recognition of aphid herbivory in concert with plant genes involved in defense against herbivores mediate plant resistance to aphids. Several such genes involved in plant disease and nematode resistance have been characterized in detail, but their existence has only recently begun to be determined for arthropod resistance. Hundreds of different genes are typically involved and the disruption of plant cell wall tissues during aphid feeding has been shown to induce defense responses in Arabidopsis , Tr iticum , Sorghum , and Nicotiana species . Mi-1.2 , a tomato gene for resistance to the potato aphid, Macrosiphum euphorbiae (Thomas), is a member of the nucleotidebinding site and leucine-rich region Class II family of disease, nematode, and arthropod resistance genes. Recent studies into the differential expression of Pto - and Pti1 -like kinase genes in wheat plants resistant to the Russian wheat aphid, Diuraphis noxia (Mordvilko), provide evidence of the involvement of the Pto class of resistance genes in arthropod resistance. An analysis of available data suggests that aphid feeding may trigger multiple signaling pathways in plants. Early signaling includes gene-for-gene recognition and defense signaling in aphid-resistant plants, and recognition of aphidinflicted cell damage in both resistant and susceptible plants. Furthermore, signaling is mediated by several compounds, including jasmonic acid, salicylic acid, ethylene, abscisic acid, giberellic acid, nitric oxide, and auxin. These signals lead to the development of direct chemical defenses against aphids and general stress-related responses that are well characterized for a number of abiotic and biotic stresses. In spite of major plant taxonomic differences, similarities exist in the types of plant genes expressed in response to feeding by different species of aphids. However, numerous differences in plant signaling and defense responses unique to specific aphid‐plant interactions have been identified and warrant further investigation.
Non-principal plane scattering from perfectly conducting, flat, rectangular plates

GTD (geometrical theory of diffraction) and PO/PTD (physical optics/physical theory of diffraction) equivalent currents are used to predict the far-field monostatic scattering from perfectly conducting, flat, rectangular plates in nonprincipal planes. To determine the accuracy of the GTD and PO/PTD equivalent currents, computations were made for a square plate with a width of 5.73 lambda . The equivalent current results are compared to moment-method (MM) computations and experimental measurements performed in an anechoic chamber. The GTD and PO/PTD equivalent currents results agree for angles away from grazing and near-grazing. For monostatic predictions, the GTD currents are as accurate as the PO/PTD equivalent currents; however, in bistatic calculations, the GTD currents contain infinite discontinuities which the PO/PTD currents avoid. The equivalent current predictions agree well with MM and experimental results for observation angles up to 45 degrees from normal incidence. >
Gfi1 regulates miR-21 and miR-196b to control myelopoiesis

The zinc finger protein growth factor independent-1 (Gfi1) is a transcriptional repressor that is critically required for normal granulocytic differentiation. GFI1 loss-of-function mutations are found in some patients with severe congenital neutropenia (SCN). The SCN-associated GFI1-mutant proteins act as dominant negatives to block granulopoiesis through selective deregulation of a subset of GFI1 target genes. Here we show that Gfi1 is a master regulator of microRNAs, and that deregulated expression of these microRNAs recapitulates a Gfi1 loss-of-function block to granulocyte colony-stimulating factor (G-CSF)-stimulated granulopoiesis. Specifically, bone marrow cells from a GFI1-mutant SCN patient and Gfi1(-/-) mice display deregulated expression of miR-21 and miR-196B expression. Flow cytometric analysis and colony assays reveal that the overexpression or depletion of either miR induces changes in myeloid development. However, coexpression of miR-21 and miR-196b (as seen in Gfi1(-/-) mice and a GFI1N382S SCN patient) completely blocks G-CSF-induced granulopoiesis. Thus, our results not only identify microRNAs whose regulation is required during myelopoiesis, but also provide an example of synergy in microRNA biologic activity and illustrate potential mechanisms underlying SCN disease pathogenesis.
SH wave scattering from 2-D fractures using boundary element method with linear slip boundary condition

SUMMARY A boundary element method (BEM) combined with a linear slip boundary condition is proposed to calculate SH wave scattering from fractures in the frequency domain. The linear slip boundary condition was proposed by Schoenberg to model elastic wave propagation through an imperfectly bonded interface, where the traction cross the interface is continuous and displacement is discontinuous. Here, we demonstrate how to simulate SH wave scattering from fractures by applying the BEM and this linear slip boundary condition. We compare the displacement discontinuity across a traction-free crack calculated using the BEM and an analytical model to show the validity and accuracy of our approach. Comparisons between results obtained using our model with those obtained using a finite difference method are also performed and very good matches between these two methods are found. An example of SH wave scattering from three curved, crossing fractures is also given.