cssi/SciSciGPT-SciSciNet huggingface dataset:
A comparison of PAMS and air toxics measurements

One of the requirements of the 1990 Clean Air Act Amendments (CAA) is that 1-h ozone nonattainment areas that are classified severe or higher category are required to operate a network of photochemical assessment monitors (PAMS) to provide hourly measurements of volatile organic compounds (VOCs) comprising of Carbon number <12 (C2–C12), along with carbonyl measurements at 3-h intervals during the summer ozone season. Often collocated with PAMS are 24-h-integrated canister and cartridge-based measurements of selected air toxic compounds, thereby providing an opportunity for inter-comparison and validation of both sets of data. In this study, we report such a comparison and estimates of trend for benzene, m-, p- and o-xylene, toluene, ethylbenzene, 1,2,4-trimethylbenzene, formaldehyde and acetaldehyde at Bronx, NY. The analysis shows that hourly PAMS and 24-h-integrated air toxics are in good agreement with each other exhibiting similar trends and that the PAMS with the higher temporal resolution offers information on excursions of the toxic compounds that would be quite useful in assessment of acute health effects. These findings were also found to be applicable to other locations such as South De Kalb, GA; Gary, IN and Lynn, MA.
Heat coefficients for p-forms on hyperbolic space

Abstract Using the trace formula we analyze the spectral zeta function for twisted p-forms on a compact real hyperbolic space. As an application we obtain explicit small-time asymptotics for the corresponding heat kernel.
Numerical Analysis of a Finite Wing Altered by a Leading-Edge Ice Accretion

References 1Rodden, W. P., and Love, J. R., “Equations of Motion of an Elastic Flight Vehicle Utilizing Static Aeroelastic Characteristics of the Restrained Vehicle,” AIAA Paper 84-0986,May 1984. 2Wykes, J. H., and Lawrence, R. E., “Aerothermoelasticity: Its Impact on Stability and Control of Winged Aerospace Vehicles,” Journal of Aircraft, Vol. 2, No. 6, 1965, pp. 517–526. 3Sheena, Z., and Karpel, M., “Static Aeroelastic Analysis Using Aircraft VibrationModes,”Proceedings of the 2nd InternationalSymposiumon Aeroelasticity and Structural Dynamics, 1985, pp. 229–232; also Israel J. Tech., Vol. 23, 1986, pp. 141, 142. 4Rodden,W. P., Giesing, J. P., and Kalman, T. P., “Re nement of theNonPlanar Aspects of the Subsonic Doublet-Lattice Lifting Surface Method,” Journal of Aircraft, Vol. 9, No. 1, 1972, pp. 69–73. 5Rodden,W. P., Taylor, P. F., andMcIntosh,S. C., Jr., “FurtherRe nement of the Nonplanar Aspects of the Subsonic Doublet-Lattice Lifting Surface Method,”InternationalCouncilof theAeronautical Sciences, Paper 96-2.8.2, Sept. 1996. 6Dusto, A. R., et al., “AMethod for Predicting the StabilityDerivatives of an Elastic Airplane; Vol. I—FLEXSTAB Theoretical Description,” NASA CR-114712, Oct. 1974; also Air Force Flight Dynamics Lab., TR-74-91, Vol. 1, Nov. 1974. 7Rodden,W. P., and Johnson,E. H.,MSC/NASTRANAeroelastic Analysis User’s Guide, MacNeal-Schwendler Corp., 1994.
Sorting in a Memory Hierarchy with Flash Memory

Flash memory continues to improve in price, capacity, reliability, durability, and performance. In addition to consumer and client devices, flash memory is also employed in many servers. Its optimal usage in various classes of server software, including web servers, file-and-print servers, and database servers, requires evaluation and analysis. The present paper analyzes the use of flash memory for database query processing including algorithms that combine flash memory and traditional disk drives. External merge sort serves as a prototypical query execution algorithm. The excellent access latency of flash memory promises substantially better sort performance than sorting with traditional disks. Surprisingly, this is true only in fairly limited cases. Flash memory as intermediate external storage improves performance in particular in situations with very limited memory. The most advantageous external sort algorithms combine flash memory and traditional disk, exploiting the fast access latency of flash memory as well as the fast transfer bandwidth and inexpensive capacity of traditional disks. Moreover, graceful degradation is required in multiple ways, both when spilling from memory to flash storage and when spilling from flash to disk. These algorithms are described in detail, including in particular their graceful transition from run generation to merging. Using such graceful degradation and incremental transitions, sorting in a three-level memory hierarchy of RAM, flash memory, and traditional disk can be generalized to database query processing with any number of levels.
Diverticulitis in a child with Williams syndrome: a case report and review of the literature

Diverticulitis is rare in pediatric patients and often associated with a more complicated course than that seen with adult patients. Certain syndromes, such as Williams syndrome, have been associated with an increase incidence of diverticular disease. We describe a 9-year-old boy with Williams syndrome who presented with rectal bleeding secondary to sigmoid diverticulitis. This case represents the youngest known patient with diverticulitis. Patients with this disorder who present with chronic or recurrent abdominal pain should be evaluated for diverticular disease and its potential complications.
Effects of hydrostatic pressure on leporine meniscus cell‐seeded PLLA scaffolds

Hydrostatic pressure (HP) is an important component of the loading environment of the knee joint. Studies with articular chondrocytes and TMJ disc fibrochondrocytes have identified certain benefits of HP for tissue engineering purposes. However, similar studies with meniscus cells are lacking. Thus, in this experiment, the effects of applying 10 MPa of HP at three different frequencies (0, 0.1, and 1 Hz) to leporine meniscus cell-seeded PLLA scaffolds were examined. HP was applied once every 3 days for 1 h for a period of 28 days. Constructs were analyzed for cellular, biochemical, and biomechanical properties. At t = 4 weeks, total collagen/scaffold was found to be significantly higher in the 10 MPa, 0 Hz group when compared with other groups. This despite the fact that the cell numbers/scaffold were found to be lower in all HP groups when compared with the culture control. Additionally, the total GAG/scaffold, instantaneous modulus, and relaxation modulus were significantly increased in the 10 MPa, 0 Hz group when compared with the culture control. In summary, this experiment provides evidence for the benefit of a 10 MPa, 0 Hz stimulus, on both biochemical and biomechanical aspects, for the purposes of meniscus tissue engineering using PLLA scaffolds.
Nerve growth factor induces transcription of NGFIA through complex regulatory elements that are also sensitive to serum and phorbol 12-myristate 13-acetate.

The expression of NGFIA (also known as egr1, zif268, TIS8, krox24, and d2) is rapidly and transiently increased by nerve growth factor (NGF) in PC12 cells. The 5'-region of this gene includes four serum response elements (SREs), a cAMP-like response element, an AP1-like response element, and an SP1-binding site. From deletion analysis of chloramphenicol acetyltransferase reporter constructs, we have established that the first 106 basepairs 5' of the transcriptional start site are sufficient for induction of NGFIA by NGF in PC12 cells; deletion beyond this point results in dramatically reduced induction of the gene. Using defined mutations in the NGFIA promoter and NGFIA-thymidine kinase hybrid promoters, we have defined three elements (SRE1, SRE2, and AP1-like) in the first 106 basepairs of upstream DNA, each of which contributes to induction of NGFIA by NGF. Cooperation by two of these elements (i.e. the two SREs or one SRE and the AP1-like element) is sufficient to confer transcriptional induction by NGF, but the combination of all three elements increased induction by NGF more effectively than a pair of elements. This suggests that the response of NGFIA to NGF is mediated by a cis-acting sequence that is composed of at least three distinct elements. An oligonucleotide composed of SRE1 and SRE2 that can confer the ability for NGF induction to heterologous promoter constructs complexes with proteins in PC12 cell nuclear extracts, but the protein-DNA complexes do not appear to be altered by NGF treatment, as measured by DNA mobility shift assays. We have also established that the regulatory region of NGFIA that mediates NGF induction also mediates the induction by serum and phorbol 12-myristate 13-acetate, suggesting that multiple signal transduction pathways must converge on these sequences to regulate the expression of this gene.
Impaired prostaglandin E1/I2 receptor activity of human blood platelets in acute ischemic heart disease.

The platelets from 74 patients with acute myocardial infarction or with unstable angina showed decreased prostaglandin E1/I2 receptor activity when compared with that of 56 normal volunteers by using [3H]prostaglandin E1 as a probe. In normals, Scatchard analyses showed the presence of one high-affinity-low-capacity (Kd1 = 9.0 +/- 1.2 nM [mean +/- SD]; n1 = 120 +/- 30 sites/cell) and one low-affinity-high-capacity (Kd2 = 1.1 +/- 0.5 microM; n2 = 1,460 +/- 250 sites/cell) prostaglandin E1/I2 receptor population in platelets. In contrast (p less than 0.01), platelets from patients showed decreased ligand binding (n1 = 40 +/- 20 sites/cell; n2 = 800 +/- 210 sites/cell) with little change in the affinity of the receptors (Kd1 = 7.50 +/- 1.6 nM; Kd2 = 0.68 +/- 0.24 microM). On the other hand, the platelets from the patients with dilated cardiomyopathy (n = 7) who were hospitalized for acute chest pain but had normal coronary arteries did not show any impairment of the receptor activity. The plasma prostacyclin...
Access, Interest, and Attitudes Toward Electronic Communication for Health Care Among Patients in the Medical Safety Net

BACKGROUND Electronic and internet-based tools for patient–provider communication are becoming the standard of care, but disparities exist in their adoption among patients. The reasons for these disparities are unclear, and few studies have looked at the potential communication technologies have to benefit vulnerable patient populations.
Hydrogen elimination from ethylene by laser-ablated Zr atoms: An infrared spectroscopic investigation of the reaction intermediates in a solid argon matrix

Intermediates of the hydrogen elimination reaction of ethylene by laser-ablated Zr atoms have been isolated in an argon matrix and investigated by means of infrared spectroscopy. The strong absorptions in the region of 1500−1660 cm-1 are due to the Zr−H stretching modes of several intermediates. There are at least three different groups of product absorptions based on the behaviors upon broad-band photolysis and annealing. Among them, the insertion and dihydrido complexes, presumed in previous studies of the hydrogen elimination of ethylene by Zr atoms, are identified. In addition, the remaining Zr−H stretching absorptions, along with absorptions in the C⋮C stretching and other regions, suggest that ethynyl zirconium trihydride is also formed in the hydrogen elimination reaction. Formation of this compound is consistent with the fact that C2H2 and C2D2 as well as CHCD are produced in the reaction of Zr + CH2CD2. Density functional theory calculations for the reaction intermediates are also carried out, an...
Staged Pelvic Closure of Extreme Pubic Diastasis in the Exstrophy-Epispadias Complex

Purpose: Staged pelvic closure has been shown to be beneficial in achieving pubic approximation in children with the exstrophy-epispadias complex. We have continued to use this procedure in children with extreme pelvic diastasis and have updated our experience.Materials and Methods: We performed closure of the pelvis in 15 patients 12 months to 14 years old presenting with a pubic diastasis of at least 8 cm (range 8 to 16). Of the patients 14 had cloacal exstrophy and 1 had classic exstrophy. Two patients with cloacal exstrophy and the patient with classic exstrophy had prior complete dehiscence at primary closure, and 1 patient with cloacal exstrophy had partial dehiscence. The technique involved bilateral innominate and vertical iliac osteotomy, and placement of a bony fixator with interfragmentary pins. The fixator was gradually closed, and soft tissue and pelvic ring closure occurred 2 to 3 weeks later. In 9 of the 15 patients an interpubic stainless steel plate was used to keep the pubis in appositio...
Flap noise prediction method for a powered lift system

A method is presented for estimating the noise generated by deflection of the engine exhaust for under-the-wing and over-the-wing versions of an externally blown flap configuration for powered lift. Correlation equations and curves are given for the overall sound pressure level and directivity and for spectra scaled to a high bypass 25,000-pound thrust size engine. Data are taken from TF34 engine tests and from large cold flow model tests. The correlations are empirical, and thus application of this prediction procedure is limited to geometrically similar configurations. Application of the method is illustrated by calculated sample footprints.
Evaluation of the new generation dual-lumen catheter for neonatal ECMO.

Objectives:The purpose of this study was to compare the newly designed dual-lumen venovenous catheter (VR13, OriGen Biomedical, Austin, TX) with the current dual-lumen catheter (VV12, OriGen Biomedical).Methods:Five newborn lambs, 1 to 5 days old and weighing 4.2 ± 0.5 kg, were cannulated with the VV13 OriGen catheter and placed on extracorporeal membrane oxygenation (ECMO). ECMO flows were increased from 200 to 600 ml/min, with measurements taken after the changes. The experiment was then repeated using the VV12 catheter.Results:Recirculation values were equal for both catheters. The pressure drop at the reinfusion port was equal for both catheters at 200 ml/min, increasing to 275 mmHg at 500 ml/min for the VR13 vs. 240 mmHg for the VV12 catheter.Conclusion:These findings indicate that the VR13 catheter resulted in levels of recirculation equal to the VV12. Based on resistance measurements, we do not recommend the use of this new catheter beyond 400 ml/min until minor design changes are made.
Rasch analysis of the functional independence measure (FIM™) mastery test

Abstract Objective: To evaluate the range, distribution, and unidimensionality of the items included in Version Five of the Functional Independence Measure (FIM TM ) Mastery Test, a 54-item written examination used to determine FIM rating proficiency by professionals who administer the instrument. Study Design: Rasch analysis of the test results of 6,645 clinicians who took the FIM Mastery Test in 1996. Results: Overall, clinicians performed well on the test. When the mean item difficulty was centered at 50, and the test scores were calibrated to range from 0 to 100 logits, the mean person ability level was 77 logits. Fit statistics indicated that the test was unidimensional, measuring a common theme. While the item separation index value was 17, 22 items were not efficient in determining the clinicians' ability levels. Analysis of the logit values by the correct response showed that descriptions of Total Assistance (Level 1) and Complete Independence (Level 7) were easiest for clinicians to score correctly. Conclusion: The examination measures the common theme of FIM knowledge in a consistent manner. Further, the results suggest that the FIM Mastery Test may be shortened, perhaps by eliminating one of the three case studies, and improved by adding more challenging questions. In addition, FIM training should focus on distinguishing among levels 2 through 6, since clinicians had more difficulty identifying these levels.
Interpreting Second-Harmonic Generation Images of Collagen I Fibrils

Fibrillar collagen, being highly noncentrosymmetric, possesses a tremendous nonlinear susceptibility. As a result, second-harmonic generation (SHG) microscopy of collagen produces extremely bright and robust signals, providing an invaluable tool for imaging tissue structure with submicron resolution. Here we discuss fundamental principles governing SHG phase matching with the tightly focusing optics used in microscopy. Their application to collagen imaging yields several biophysical features characteristic of native collagen structure: SHG radiates from the shell of a collagen fibril, rather than from its bulk. This SHG shell may correspond to the supporting element of the fibril. Physiologically relevant changes in solution ionic strength alter the ratio of forward-to-backward propagating SHG, implying a resulting change in the SHG shell thickness. Fibrillogenesis can be resolved in immature tissue by directly imaging backward-propagating SHG. Such findings are crucial to the design and development of forthcoming diagnostic and research tools.
Polynomial clone reducibility

Polynomial clone reducibilities are generalizations of the truth-table reducibilities. A polynomial clone is a set of functions over a finite set X that is closed under composition and contains all the constant and projection functions. For a fixed polynomial clone $${\fancyscript{C}}$$ C , a sequence $${B\in X^{\omega}}$$ B ? X ? is $${\fancyscript{C}}$$ C -reducible to $${A \in {X}^{\omega}}$$ A ? X ? if there is an algorithm that computes B from A using only effectively selected functions from $${\fancyscript{C}}$$ C . We show that if A is Kurtz random and $${\fancyscript{C}_{1} \nsubseteq \fancyscript{C}_{2}}$$ C 1 ? C 2 are polynomial clones, then there is a B that is $${\fancyscript{C}_{1}}$$ C 1 -reducible to A but not $${\fancyscript{C}_{2}}$$ C 2 -reducible to A. This implies a generalization of a result first proved by Lachlan (Z Math Logik Grundlagen Math 11:17---44, 1965) for the case |X| = 2. We also show that the same result holds if Kurtz random is replaced by Kolmogorov---Loveland stochastic.
A new neoplastic mast cell grown in culture.

Abstract A mastocytoma of Furth was grown in culture and the clones isolated and grown. The cells form histamine and 5-hydroxytryptamine from the precursor amino acids. The cells take up preformed histamine and 5-hydroxytryptamine. Neither amine is catabolized by the cells. The steady-state levels of the amines in the cells fluctuate with time. The observations made on these cells are compared with those on other neoplastic mast cells and on normal mast cells.
Preparation of superconducting YBa2Cu3O7 from the corresponding metal formates.

Superconductive YBa/sub 2/Cu/sub 3/O/sub 7/ was prepared from a mixture of yttrium, barium, and copper (II) formates in flowing oxygen. The product was obtained by single-cycle heating to 920 /sup 0/C. Unlike conventional preparations, the orthorhombic phase is obtained without the requirement of an extended annealing period. Magnetic susceptibility measurements show the onset of superconductivity occurs at 95 K with a magnetic-flux expulsion of 5% at lower temperatures. X-ray powder diffraction data show the material to be predominantly the orthorhombic phase, with excess BaO impurity and none of the tetragonal phase present
Integrating rapid responses to 1,25-dihydroxyvitamin D3 with transcriptional changes in osteoblasts: Ca2+ regulated pathways to the nucleus.

Abstract It is well established that 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) treatment of target cells including osteoblasts activates both membrane-initiated rapid Ca2+ responses linked to influx through voltage sensitive Ca2+ channels (VSCCs) and longer term nuclear receptor-mediated changes in gene expression. We recently reported use of a cDNA microarray strategy to identify transcriptional changes after 3 and 24 h of treatment with 1,25(OH)2D3 and with an analog of 1,25(OH)2D3 (25(OH)-16ene-23yne-D3 [AT]) that activates Ca2+ influx without binding to the nuclear receptor. Among 5000 different clones on the array filters, we identified families of genes in osteoblasts that were altered two-fold or greater following treatment with 1,25(OH)2D3 or analog AT for 3 h. Cluster analysis further revealed complex patterns of changes in gene expression, indicative of multiple pathways to the nucleus. Evidenced by changes in target gene expression, activation of a Ca2+/CaMK/CREB/CRE pathway clearly occurs and modulates expression of a variety of genes associated with changes in protein secretion including those involved in paracrine regulation of bone resorption, RANKL and osteoprotegerin (OPG). The changes in gene expression can be inhibited by L-type VSCC channel blockers, confirming the role of Ca2+ entry in pathway activation. These findings provide clear evidence of rapid changes in gene expression associated with Ca2+ influx after treatment with 1,25(OH)2D3, and open the door to novel nuclear receptor-independent signaling pathways that affect gene transcription.
Cortical spreading depression causes a long-lasting decrease in cerebral blood flow and induces tolerance to permanent focal ischemia in rat brain.

Cortical spreading depression (CSD) has previously been shown to induce tolerance to a subsequent episode of transient cerebral ischemia. The objective of the present study was to determine whether CSD also induces tolerance to permanent focal ischemia and, if so, whether tolerance may be mediated by alterations in cerebral blood flow (CBF). Sprague-Dawley rats were preconditioned by applying potassium chloride to one hemisphere for 2 hours, evoking 19 ± 5 episodes of CSD (mean ± SD, n = 19). Three days later, the middle cerebral artery (MCA) was permanently occluded using an intraluminal suture. In a subset of animals, laser Doppler blood flow (LDF) was monitored over the parietal cortex before and during the first 2 hours of MCA occlusion. Preconditioning with CSD reduced the hemispheric volume of infarction from 248 ± 115 mm3 (n = 18) in sham-conditioned animals to 161 ± 81 mm3 (n = 19, P < 0.02). Similarly, CSD reduced the neocortical volume of infarction from 126 ± 82 mm3 to 60 ± 61 mm3 (P < 0.01). M...
Design and performance of a high-volume compound annular denuder

Abstract A laminar flow model incorporating variable collisional reaction efficiency is developed and applied for the design of annular denuders. Efficiencies predicted with the model show excellent agreement with published empirical data for annular denuders that are used for collection of SO 2 , but point to potential errors in extending the empirical data to different chemical systems. The design and construction of a compound annular denuder for collection of polynuclear aromatic hydrocarbon (PAH) vapor are described. This denuder, which consists of a nested set of cylindrical tubes, is shown to operate efficiently at sampling rates of up to 3.33 l s −1 while maintaining essentially 100 per cent transmission of micron-sized particulate matter.
Michael addition reactions between various nucleophilic glycine equivalents and (S,E)-1-enoyl-5-oxo-N-phenylpyrrolidine-2-carboxamide, an optimal type of chiral Michael acceptor in the asymmetric synthesis of β-phenyl pyroglutamic acid and related compounds

(S)-5-Oxo-N-phenyl-1-[(E)-3-phenylacryloyl]pyrrolidine-2-carboxamide, easily prepared from inexpensive and readily available, in both enantiomeric forms, glutamic/pyroglutamic acid was designed as an optimal type of chiral Michael acceptor for reactions with a series of nucleophilic glycine equivalents. A study of the corresponding Michael addition reactions revealed that the new generation of modular glycine derivatives, as a counterpart to the Michael acceptor, provides for operationally convenient preparation of β-phenyl pyroglutamic acids and related compounds with virtually complete chemical and stereochemical outcomes.
Children with moderately elevated blood lead levels: a role for other diagnostic tests?

In this study we examined potential limitations of relying exclusively on blood lead (BPb) levels to evaluate children with moderately elevated BPb levels (1.21-2.12 micromol/l, or 25-44 microg/dl). We tested the following hypotheses: 1) such children without elevated erythrocyte protoporphyrin (EP) levels (>=0.62 micromol/l or >/= 35 microg/dl) are unlikely to respond to a chelating agent with a brisk urinary Pb diuresis; 2) those with elevated EP levels, but low hematologic indices consistent with iron deficiency, are also unlikely to respond to a chelating agent with a robust urinary Pb diuresis; and 3) those with elevated EP levels and iron sufficiency are more likely to respond to a chelating agent. To test these hypotheses, we performed retrospective analyses of the relationships between EP concentrations, hematologic indices, and urinary Pb excretion ratios (uPbr) in moderately Pb-poisoned children undergoing the CaNa2EDTA lead mobilization test (Pb-MT). Data from 122 children were available. Urinary Pb excretion was limited in children with an EP =0.6). In children with an EP >=0.62 micromol/l, low hematologic indices, such as a mean corpuscular hemoglobin (MCH) /= 0.62 micromol/l and iron sufficiency (p /= 0.62 micromol/l and either MCH /= 23 pg). We conclude that only a minority of moderately Pb-poisoned children will demonstrate enhanced urinary Pb excretion in response to chelation therapy. Some of the predicted nonresponders can be readily identified by adding the EP and complete blood count to the panel of tests performed.
Amplitude of visual evoked potentials as a function of illuminance

Recording electrodes were implanted in the lateral geniculate body and striate cortex of rabbits and cats. Primary evoked responses to a brief light flash were recorded from the two locations in the unanesthetized animal. Both at geniculate and cortical levels a power function was found to express satisfactorily in the two species the relationship of response amplitude to illuminance, although a log function generally provided almost as good a fit for the data.
Echogenic adnexal masses associated with first-trimester pregnancy: Sonographic appearance and clinical significance

In a retrospective survey of a large obstetrical ultrasound experience, 10 echogenic adnexal masses in nine patients with a coexistent intrauterine pregnancy were detected and analyzed. Definitive follow-up data available for seven of the nine patients disclosed three ovarian teratomas, two hemorrhagic corpus luteum cysts, one endometrioma, one inflammatory mass, and one colonic pseudomass. In one additional patient, an echogenic ectopic pregnancy with an intrauterine pseudogestational sac simulated the above entities. Conservative management with follow-up sonography is generally indicated for echogenic masses coexistent with first-trimester intrauterine pregnancies.
Review of the present status of the theory of superconductivity

Theory and experiment are compared for a number of phenomena in superconductors. While the agreement is generally good, there are some discrepancies for which there is no adequate explanation.
Nuclear magnetic resonance structure of a prototype Lin12-Notch repeat module from human Notch1.

Notch1 is a member of a conserved family of large modular heterodimeric type 1 transmembrane receptors that control differentiation in multicellular animals. Receptor maturation is accompanied by a furin-dependent cleavage that converts the Notch1 precursor polypeptide into a heterodimer consisting of an extracellular ligand-binding subunit (NEC) and a transmembrane signaling subunit (NTM). Binding of a physiologic ligand to NEC induces signaling by triggering additional proteolytic cleavages in NTM, which allow its intracellular region to translocate to the nucleus where it participates in a transcriptional activation complex. In the absence of ligand, the three conserved LNR modules of the NEC subunit participate in maintaining the receptor in its resting conformation. Here, we report the solution structure of the first LNR module (LNR_A) of human Notch1, and identify residues of LNR_A perturbed by the presence of the adjacent module LNR_B. LNR_A is held together by a unique arrangement of three disulfide bonds and a single bound Ca 2+ ion, and adopts a novel fold that falls in the general class of irregular disulfide-bonded structures. Residues perturbed by the presence of the adjacent LNR_B module are predominantly hydrophobic, and lie on one face of the module. These studies represent an initial step toward understanding the structural interrelationships among the three contiguous LNR modules required for proper regulation of Notch signaling.
On subspace-hypercyclic operators

In this paper we study an operator T on a Banach space E which is M-hypercyclic for some subspace M of E. We give a sufficient condition for such an operator to be M-hypercyclic and use it to answer negatively two questions asked by Madore and Martinez-Avendano. We also give a sufficient condition for T to be M-hypercyclic for all finite co-dimensional subspaces M in E.
Invasiveness in wetland plants in temperate North America.

The spread of invasive taxa, includingLythrum salicaria, Typha × glauca, Myriophyllum spicatum, Phalaris arundinacea, andPhragmites australis, has dramatically changed the vegetation of many wetlands of North America. Three theories have been advanced to explain the nature of plant invasiveness. Aggressive growth during geographic expansion could result because 1) growth is more favorable under new environmental conditions than those of resident locales (environmental constraints hypothesis); 2) herbivores may be absent in the new locale, resulting in selection of genotypes with improved competitive ability and reduced allocation to herbivore defenses (evolution of increased competitive ability hypothesis); and 3) interspecific hybridization occurred between a new taxon and one existing in an area, resulting in novel phenotypes with selective advantages in disturbed sites or phenotypes that can grow under conditions not favorable for either parent (introgression/hybrid speciation hypothesis). A review of published literature found few studies that compare the growth and dynamics of invasive populations in their new range versus those in historic ranges. However, there is evidence that hydrologic alterations could facilitate invasions byTypha × glauca andPhalaris arundinacea and that increased salinity promoted spread ofTypha angustifolia (parental taxon) andPhlaris arundinacea and that increased salinity promoted spread ofTypha angustifolia (parental taxon) andPhragmites australis. The potential for reduced herbivory causing aggressive growth is greatest forLythrum salicaria. Introgressive hybridization is potentially a cause of invasiveness for all five species but has been established only forTypha × glauca andLythrum salicaria.
Pathways linking Aβ and tau pathologies

Abeta (amyloid beta-peptide) and tau are the main proteins that misfold and accumulate in amyloid plaques and NFTs (neurofibrillary tangles) of Alzheimer's disease and other neurological disorders. Historically, because plaques and NFTs accumulate in diverse cellular compartments, i.e. mainly extracellularly for plaques and intracellularly for NFTs, it was long presumed that the constituent proteins formed these lesions via unrelated pathways. Animal and cell studies over the last decade, however, have provided convincing evidence to show that Abeta can facilitate the development of tau pathology by altering several cell-dependent and -independent mechanisms. In the present article, results are reviewed from several laboratories that show that modulating Abeta pathology can directly affect the development of tau pathology, which has significant implications for the treatment of Alzheimer's disease.
Nanoscale materials synthesis. 1. Solvent effects on hydridoborate reduction of copper ions

The reduction of CuBr2 by NaBH4 in a variety of solvents yields nanoscale metallic copper as the primary product. Although the product of this reaction is largely solvent independent, the studies show that reaction times, the total volume of gaseous products, and nanoscale particle sizes are dependent on solvent properties. The reaction occurred instantaneously in polar, protic, and acidic solvents such as methanol and ethanol. In contrast, in polar, aprotic, and coordinating solvents such as tetrahydrofuran and acetonitrile, the reaction was slow. Particle sizes increased as the rate of reaction decreased. For solvents in which similar reaction times were observed, the reaction carried out in polar, aprotic, and coordinating solvents yielded copper samples with larger particle sizes. The acid properties of the solvent controlled the amount of gas evolved in these experiments.
Upper airway dysfunction--an unusual presentation of Guillain-Barré syndrome.

We report the case of a 9-year-old boy who presented to the emergency department with dysphagia, respiratory distress, hoarseness, and generalized weakness. While in the ED, his respiratory status deteriorated, and he required intubation. At that time, he was found to have normal upper airway anatomy. He was admitted to the pediatric ICU and, within 24 hours, developed areflexia and muscle weakness; he was diagnosed with Guillain-Barre syndrome. Atypical presentations of Guillain-Barre syndrome are discussed, and the necessity of considering this diagnosis when evaluating patients with evidence of cranial nerve dysfunction or upper airway distress is emphasized.
Activation of α-adrenoceptors indirectly facilitates sodium pumping in frog motoneurons

The effects of clonidine on Na+ pumping in motoneurons of the isolated frog spinal cord was investigated using sucrose gap recordings from ventral roots. Na+ pump activity, induced in motoneurons either by tetanizing the dorsal root or by rapidly exposing the cord to normal medium following 30 min in K+-free Ringer's solution (K+-activated hyperpolarizations), was increased by application of clonidine (100 μM). These actions of clonidine were blocked by the preferential α2-adrenergic antagonist yohimbine, but not by α1-adrenergic antagonist prazosin or the β-blocker propranolol. Clonidine's effects on Na+ pumping appeared to be indirect (presumably via interneurons) because its effects on K+-activated hyperpolarizations were reduced by tetrodotoxin (TTX) or high concentrations of Mg2+. This indirect mechanism involved activation of non-NMDA excitatory amino acid receptors. Thus, in the presence of clonidine, CNQX, but not APH, limited the ability of clonidine to enhance K+-activated hyperpolarizations. The AMPA receptor may play a role in the process. K+-activated hyperpolarizations were augmented by the presence of AMPA; NMDA had no effect. The present results are consistent with the idea that activation of α2-adrenoceptors produces the following: the release of excitatory amino acids from interneurons; the activation of non-NMDA receptors on motoneurons; increased Na+ influx and loading and increased Na+ pump activity.
Psychobiology of maternal behavior: contribution to the clinical understanding of maternal behavior among humans.

Psychobiological studies of maternal behavior among non-primate mammals have arrived at several general conclusions that may aid in our understanding of human maternal behavior and in the clinical treatment of parenting disorders. The hormonal basis of maternal behavior arises during pregnancy and consists of a hormonal priming phase, extending over most of pregnancy, and a hormonal triggering phase at the end of pregnancy. Hormonal priming in several species depends upon estrogen, progesterone and prolactin, and hormonal triggering depends upon a decline in progesterone and an increase in estrogen, prolactin and oxytocin in different species. The onset of maternal behavior is hormonally based but postpartum maternal behavior in several species is based upon the stimulation that the mother receives from her young (i.e. is non-hormonally based). There is a transition period between these two phases soon after parturition during which contact with the young plays a crucial role in the maintenance of maternal behavior. The onset of maternal behavior may be viewed as the resolution of conflict between approach and withdrawal responses of females to their offspring.
Troponin T core structure and the regulatory NH2-terminal variable region.

The conserved central and COOH-terminal regions of troponin T (TnT) interact with troponin C, troponin I, and tropomyosin to regulate striated muscle contraction. Phylogenic data show that the NH2-terminal region has evolved as an addition to the conserved core structure of TnT. This NH2-terminal region does not bind other thin filament proteins, and its sequence is hypervariable between fiber type and developmental isoforms. Previous studies have demonstrated that NH2-terminal modifications alter the COOH-terminal conformation of TnT and thin filament Ca2+-activation, yet the functional core structure of TnT and the mechanism of NH2-terminal modulation are not well understood. To define the TnT core structure and investigate the regulatory role of the NH2-terminal variable region, we investigated two classes of model TnT molecules: (1) NH2-terminal truncated cardiac TnT and (2) chimera proteins consisting of an acidic or basic skeletal muscle TnT NH2-terminus spliced to the cardiac TnT core. Deletion of...
Non-specific binding and saturation of Polysorbate-20 with aseptic filter membranes for drug substance and drug product during mAb production

An issue identified during filtration of mAb drug substance is Polysorbate-20 absorption by polyethersulfone filter membranes. Experiments determined that both polyvinylidene fluoride filter membranes and polyethersulfone filter membranes bind Polysorbate-20. Saturation point, bound surfactant amount per square cm of membrane, and non-specific binding mechanisms are described in this report. An appropriate approach for preventing Polysorbate-20 loss in drug substance and drug product is presented.
Comments on Pardoe and Weitner: sentencing convicted felons in the United States: a Bayesian analysis using multilevel covariates

This paper presents a regression analysis of the factors related to sentencing, which is obviously a very complicated and important problem. Iwillmake somevery general remarks about the paper, because I consider it to be a representative example of a general approach to statistical analysis. As an example, it looks quite good, although I am not an expert in sentencing. But neither are the authors, I think. Most important, from my point of view, is that the general approach is deeply flawed. From the methodological point of view, the paper uses techniques which differ from logistic regression analysis popular in criminology. It replaces logistic regression by multilevel logistic regression, and, as a further elaboration, it replaces the conventional multilevel analysis ofWong and Mason (1985) by a fully Bayesian approach. The question we have to answer is simple: does this analysis improve on standard logistic regression analysis? And can we expect the results of the analysis to be more reliable and interesting? Unfortunately, there are several problems with the paper, or more precisely with this type of statistical analysis, that make it difficult to give a positive answer to these questions. Why do Pardoe et al. (and many other social and behavioral scientists with similar data structures) argue that it makes sense to use multilevel analysis in this context? If we look in the multilevel literature for a general answer, we are in for some disappointment. As in various other social science statistics contexts, arguments are often replaced by references to presumably unassailable expert sources. We see this in an early discussion of factor analysis, in the literature around LISREL and structural equation models, and now again in multilevel analysis. Pardoe et al. maintain, for instance, that conventional logistic regression
Aneurysm of the arterial duct—a case report and review of the literature

Aneurysmal dilatation is a rare malformation of the arterial duct. Successful repair of this anomaly was achieved in a five-day-old neonate, using deep hypothermia and circulatory arrest. Of the cases of aneurysm of the arterial duct reported in the English literature, only seven have been treated surgically with success.
Desipramine attenuates working memory impairments induced by partial loss of catecholamines in the rat medial prefrontal cortex.

The density of tyrosine hydroxylase-immunoreactive (TH-IR) axons in the prefrontal cortex of schizophrenic subjects may be reduced by as much as 50% in the deep cortical layers (Am J Psychiatry 156:1580–1589, 1999). Previously, we demonstrated that ~60% loss of TH-IR axons in the rat medial prefrontal cortex (mPFC) decreases local basal and stress-evoked extracellular dopamine (DA) concentrations, suggesting that moderate loss of DA axons in the mPFC is sufficient to alter the neurochemical activity of the remaining DA neurons (Neuroscience 93:497–505, 1999). To further assess the functional consequences of partial mPFC DA depletion, we examined the effects of 6-hydroxydopamine lesions of the rat mPFC on behavior in a T-maze delayed-response task. We also assessed whether chronic administration of the norepinephrine (NE) uptake inhibitor, desipramine (DMI), attenuates lesion-induced deficits in T-maze performance. Previous research indicates that inhibition of NE transport in the mPFC results in a concomitant increase in extracellular DA and NE. Moderate loss of mPFC DA and NE (~50 and 10% loss, respectively) was sufficient to impair delayed-response behavior, in part due to an increase in perseverative responding. Chronic DMI treatment (3 mg/kg delivered via osmotic pumps) impaired performance of control rats but attenuated the deficits in delayed-response behavior in rats previously sustaining loss of mPFC DA and NE (~75 and 35% loss, respectively). These data suggest that moderate loss of DA and NE in the prefrontal cortex is sufficient to impair cognitive function, and these behavioral effects are attenuated by inhibition of the NE transporter.
Does Hyperuricemia Protect from Rheumatoid Inflammation

The negative association between gout and rheumatoid arthritis is well accepted. The reason for this mutual exclusion is not clear; a protective immunosuppressive effect of hyperuricemia has been included among possible explanations. To test this hypothesis, we reviewed the charts of 160 rheumatoid arthritis patients on whom clinical information and followup for at least a year were available. We selected those patients with persistent hyperuricemia as defined by serum urate levels averaging above 7.5 mg% for at least 6 months. We found 12 patients fulfilling such criteria, and 11 of these were judged to have quiescent, minimally active, or inactive disease during hyperuricemic periods. In 2 patients, flares of the rheumatoid process coincided with normalization of serum urate levels. We propose that persistent hyperuricemia may protect against or decrease the expression of rheumatoid inflammation.
The chromatic polynomial of an unlabeled graph

We investigate the chromatic polynomial χ(G, λ) of an unlabeled graph G. It is shown that χ(G, λ) = (1|A(g)|) Σπ ∈ A(g) χ(g, π, λ), where g is any labeled version of G, A(g) is the automorphism group of g and χ(g, π, λ) is the chromatic polynomial for colorings of g fixed by π. The above expression shows that χ(G, λ) is a rational polynomial of degree n = |V(G)| with leading coefficient 1|A(g)|. Though χ(G, λ) does not satisfy chromatic reduction, each polynomial χ(g, π, λ) does, thus yielding a simple method for computing χ(G, λ). We also show that the number N(G) of acyclic orientations of G is related to the argument λ = −1 by the formula N(G) = (1|A(g)|) Σπ ∈ A(g)(−1)s(π) χ(g, π, −1), where s(π) is the number of cycles of π. This information is used to derive Robinson's (“Combinatorial Mathematics V” (Proc. 5th Austral. Conf. 1976), Lecture Notes in Math. Vol. 622, pp. 28–43, Springer-Verlag, New York/Berlin, 1977) cycle index sum equations for counting unlabeled acyclic digraphs.
Analysis of air return alternatives for CRS-type open volumetric reciever

Abstract Even though air-cooled receivers provide substantial benefits, such as low inertia and quick sun-following dispatchability, and the volumetric effect leads to designs with aperture areas similar to those used in molten salt or water/steam receivers, some concern persists regarding absorber durability, reduction of radiation losses and improvement of the air return ratio (ARR). The paper focuses on this last issue, since the ARR is a source of significant receiver losses in current designs. Today’s scaled-up receivers claim values between 45 and 70% for ARR, which means, in terms of energy loss, between 5 and 15%. As a consequence of ARR and the radiation loss stemming from high working temperatures, open volumetric receivers efficiencies below 75% are reported at temperatures usable by the power block. Those values may be acceptable for a first demonstration plant, but are categorically not competitive for commercial schemes in which receiver efficiency should approach 90%. This paper discusses the impact of several geometrical properties of the absorber and air injection system used. The study was performed by CFD with the FLUENT code. The assessment considered such alternatives as modularity of the air return system (HITREC receiver concept), outer ring injection with air curtain effect or cavity aperture (with and without secondary concentrator). A detailed analysis reveals that some parts of the receiver aperture achieve an ARR above 90% at well-selected operating conditions, but average values hardly surpass 70%. Therefore, a careful design should keep in mind important variables such as the effects of receiver edge and lateral wind, as well as air injection angle.
TU‐C‐L100J‐05: A Practical Filmless Technique of Determining CT Beam Width

Purpose: To develop a filmless technique for the measurement of CT beam width for QA. Method and Materials:Images of pre‐patient collimated CT beams were acquired using Fuji computed radiography(CR) cassettes and direct‐exposure film (DF). CR cassettes were exposed using 80kV, 10mAs to avoid signal saturation. The DF was exposed at 80kV, 30mAs to achieve a proper optical density. The DF image was digitized then linearized. To achieve a proper signal range for CR, various plate‐reading protocols were evaluated. An IDL program was developed to automatically handle both the digitized film and a variety of CRimage sizes. “Unprocessed” logarithmic CR data were linearized, which is critical to validate the FWHM. The program executes in an interactive fashion, whereby the user selects the beam to analyze. The program determines the background signal for subtraction then samples multiple cross‐beam profiles to form an averaged profile. The profile is smoothed and the FWHM is determined. Results: Under proper conditions of image acquisition, results show both DF and CR are appropriate techniques for beam width measurements. The CR technique demonstrated a high level of reproducibility with a coefficient of variation below 0.5%. Also, the CR results were within 0.3mm of specifications. Using various sizes of CR cassettes had a minimal effect on the results. However, if the properly exposed image is saturated due to an inappropriate CR plate reading protocol, the inaccuracy is substantial (>1mm). The technique worked well for annual tests of six GEscanners. Over a wide range of beam width configurations, all measurements were within 0.9mm of specifications. Conclusion: A technique for determination of CT beam width in a filmless environment was developed and tested. The results obtained using CR yield accurate measurements of CT beam profile width. The technique is effective, practical, and has proven to be robust.