cssi/SciSciGPT-SciSciNet huggingface dataset:
The complexity of the satisfiability problem for Krom formulas

Abstract We study the computational complexity of the satisfiability problem for Krom (CNF-2) formulas. Upper and lower bounds are obtained for several decidable classes of formulas determined by quantifier prefix and degree of predicate letters. For example, we show that determining satisfiability of Krom formulas with quantifier prefix of the form ∃…∃∀…∀∃…∃ is complete for deterministic exponential time, but that if the number of universal quantifiers is bounded then polynomial time suffices.
In vitro germination of Paphiopedilum seed on a completely defined medium

Abstract Seed germination and seedling survival of Paphiopedilum cultured aseptically for 8 months in darkness or in the light varied with seed source, culture medium and incubation environment. In the light, germination was best and nearly equal on Burgeff EG-1, Thomale GD, and Norstog media, but more seedlings survived on Burgeff EG-1. Comparing incubation environments, the best germination and seedling survival occurred in the dark on either Norstog or Thomale GD, suggesting that increased production of Paphiopedilum from seed may require germination and early seedling growth in darkness. Since the Norstog medium is completely defined, it can be used to determine which organic constituents are vital for asymbiotic germination and growth of Paphiopedilum .
Spectral analysis of traveling waves for nonlocal evolution equations

Monotone traveling waves have been shown to exist for a broad class of nonlocal bistable evolution equations. In this note we examine the spectrum of the operator obtained by linearizing about such a traveling wave and hence show that these waves are exponentially asymptotically stable, up to translation.
Polarization in a snap: imaging polarimetry with micropolarizer arrays

Polarization, flux, and the spectral energy distribution of light are the fundamental parameters that we measure in order to infer properties of the sources of electromagnetic radiation, such as intensity, temperature, chemical composition and physical geometry. Recently, the fabrication of microgrid polarizer arrays (MPAs) facilitated the development of a new class of division-of-focal plane polarimeters. These devices are capable of measuring the degree and angle of polarization across a scene with a single exposure. We present the design of the Rochester Institute of Technology Polarization Imaging Camera (RITPIC), a snapshot polarimeter for visible and near-infrared remote sensing applications. RITPIC is a compact, light-weight and mechanically robust imaging polarimeter that is deployable on terrestrial, naval, airborne and space-based platforms. RITPIC is developed using commercially available components and is capable of fast cadence imaging polarimetry of a wide variety of scenes. We derive the expected performance of RITPIC using the first high resolution 3D finite-difference time-domain (FDTD) models of these hybrid focal planes and simulated observations of synthetic scenes rendered with the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model. Furthermore, we explore applications in remote sensing for which RITPIC, and devices like it, provide unique advantages.
Novel approach to design of a stable and robust fuzzy controller for a class of nonlinear systems

In this paper, the concept of variable structure system (VSS) with sliding mode was used to develop a fuzzy controller for a class of nonlinear system. The proposed sliding mode fuzzy controller (SMFC) preserves the fundamental property of sliding mode control that is stability and robustness in the presence of disturbances and model uncertainties. To reduce the number of design parameters in SMFC, we adopted the concept of parameterization or input-output mapping factor and devised a systematic tool for analyzing and enhancing the performance of SMFC. For demonstration, we applied the SMFC to the inverted pendulum problem. Simulation results indicates that the fuzzy sliding mode control perform well in the presence of disturbances and is insensitive to the parameter variation of the system.
Mastocytosis complicating pregnancy.

Abstract Objective: To review the experience of women who conceived after developing mastocytosis and who were observed at the National Institutes of Health. Methods: We reviewed our patient database for the years 1984–1998 to identify women with mastocytosis who had conceived. We then reviewed each woman’s record, asked each woman to complete a questionnaire, and with permission wrote outside hospitals to obtain records of each labor and delivery. Results: We identified eight women who had become pregnant. These women delivered a total of 11 live infants. In approximately a third of the pregnancies, patients experienced worsening of symptoms. They often used fewer medications during pregnancy because of safety concerns, and no greater incidence of adverse reactions was noted. Antihistamines were used most commonly, followed by oral prednisone. Medications used during delivery were well tolerated and included epidural analgesics. Neonates were generally healthy. None to date have developed urticaria pigmentosa or systemic mastocytosis. Conclusion: A subset of women with mastocytosis might have had exacerbated mastocytosis during and after pregnancy, but labor and delivery progressed normally. Infants were born generally healthy and were without mastocytosis. Thus there appears to be no absolute contraindication to pregnancy for women with mastocytosis, although women should be aware that the choice to have a child is not without some added risk. (Obstet Gynecol 2000;95:391–5.)
Perturbation theory of scattering of a particle by an identical bound particle—II

Scattering of a particle by an identical particle in a bound state (for instance, scattering of an electron by a Hydrogen atom) is treated by a new method. This is based on the use of a Schrodinger equation for a two-component wave function, with a Hamiltonian which is a 2 × 2 matrix. One, and only one, linear combination of the components of the wave function is a solution of the ordinary Schrodinger equation for two identical particles in a field of force and interacting with each other. Such a linear combination has the symmetry required by the Pauli principle.
Plasma-Enhanced Atomic Layer Deposition of Semiconductor Grade ZnO Using Dimethyl Zinc†

Zinc oxide films are deposited over the temperature range 25–120 °C by plasma-enhanced atomic layer deposition (PEALD) using dimethyl zinc (DMZ, Zn(CH3)2) as the metal precursor. DMZ is unreactive with molecular oxygen under process conditions, facilitating its utility for PEALD. The deposition rate is independent of plasma exposure (1–5 s) and saturates for DMZ exposures ≥75 mTorr s. The saturated growth per cycle increases from 1.6 to 2.9 A per cycle as the temperature is increased from 25 to 85 °C, and remains constant in the range 85–120 °C. Over the narrow range explored, substrate temperature has a dramatic impact on film structure and properties. Polycrystalline films with a (100) texture are obtained at room temperature, with the preferred orientation evolving to the (002) direction as the temperature increases. The electrical resistivity decreases exponentially from 270 at room temperature to values of ∼5 Ω cm within the ALD window. Compositional analysis shows that films at low temperature are contaminated by carbon and hydroxyl impurities, however these defects are attenuated with temperature and not detected in films deposited within the ALD window. Room temperature photoluminescence is dominated by strong emission from ZnO defects in most films, however these signals are attenuated and strong band edge emission is observed for films deposited at 120 °C.
Nutritional status of elderly trauma patients presenting to a South Dublin Teaching Hospital

Abstract Background It has been hypothesised that elderly orthopaedic trauma patients may be malnourished when compared to the general population. We conducted an observational study to identify if this was the case. Methods Thirty elderly trauma patients (≥ 65 years) admitted to the orthopaedic unit were recruited. Serum markers (albumin, urea, creatinine, sodium, potassium, haemoglobin, white cell count, platelets, lymphocytes, C-reactive protein, magnesium, calcium) anthropometric measurements (triceps skin-fold thickness, mid-arm circumference, body mass index) and short form mini-nutritional assessment (MNA-SF®) were carried out at presentation and at 3 months postoperation. Serum markers were also repeated at day 1 and day 3 postoperation. Results Sixty percent had an initial mini-nutritional assessment (MNA-SF®) score of less or equal to 11 points indicating that they were at risk from possible malnutrition. However, median BMI at presentation was normal at 22.79 kg/m2 (WHO guidelines) (Interquartile range [IQR] 19.8–28). Interestingly, a higher proportion of the group (67%) were below the 50th centile for age related BMI centiles. At follow-up (15 patients), there was no significant difference in anthropometric measures. The mean MNA-SF® had increased, but not significantly (P = 0.121). Conclusions It could be extrapolated from this study that elderly trauma patients may be at risk of malnutrition regardless of their BMI at presentation and should be screened using validated nutrition screening tools and monitored. The use of age specific centiles is also recommended. Further research is needed using larger sample sizes to confirm these findings.
Histologic Changes of Doxycycline Pleurodesis in Rabbits: Effect of Concentration and pH

The effects of doxycycline hyclate (DOXY) pleurodesis were compared with those of tetracycline hydrochloride (TCN) in 25 healthy New Zealand White rabbits. One group of rabbits received TCN (pH 2.0) in the left pleural space at a concentration of 35 mg/kg in 3.0 ml of saline solution. Four other groups of rabbits received DOXY in two concentrations (35 mg/kg or 10 mg/kg) and at two pHs (an acid of 2.0 and a NaOH neutralized pH of 7.6). No attempt was made to drain the pleural space after pleurodesis. At autopsy 2 weeks later, bloody fluid filled the pleural cavity and extensive intrapleural adhesions compressed the underlying lung. Microscopically, fibrin and collagen were diffusely deposited in the pleural connective tissue and in the intrapleural adhesions. The visceral pleural thickness increased from its normal value of 0.01 mm to values of 0.5 to 0.9 mm in the TCN and DOXY groups. Fibroblasts were the predominant inflammatory cell in the pleural connective tissue with few neutrophils or lymphocytes. No significant differences of histologic characteristics were observed between the TCN and DOXY groups. Alterations in pH or concentration in the DOXY groups produced similar changes in the gross and microscopic appearance of the pleural space. We conclude that DOXY is as effective as TCN in producing chemical pleurodesis. Doxycycline concentrations of 10 mg/kg were sufficient to substantially sclerose the pleural space in these healthy rabbits. Doxycycline pleurodesis was effective at neutral pH suggesting a mechanism of action independent of acid injury to the mesothelium.
High ventricular septal defect and slight dextroposition of the aorta (Eisenmenger complex) associated with deformed aortic valve simulating patent ductus arteriosus

Summary 1. A second case is presented with a continuous murmur heard in thesecond left intercostal space resembling the murmur of patent ductus arteriosus, in which necropsy revealed a high interventricular septal defect and slight dextroposition of the aorta (Eisenmenger complex) associated with deformity of the aortic valve. 2. Intracardiac catheterization with the use of a manometer capable of registering systolic and diastolic pressures might have established the diagnosis before operation and death. 3. Intracardiac catheterization is not recommended for individuals withcontinuous murmur in the pulmonary area, normal electrocardiogram, and relatively small hearts. 4. Before surgical treatment is undertaken intracardiac catheterization is recommended for individuals with a continuous murmur in the pulmonary area and marked cardiac enlargement who show abnormal features in the phonocardiogram or who present the diastolic murmur of aortic insufficiency or a systolic thrill and murmur near the xiphoid, suggesting the existence of an interventricular septal defect.
Enhancement of histamine-induced vascular leakage by pertussis toxin in SJL/J mice but not BALB/c mice

Pertussis toxin (PTX) from Bordetella pertussis is known to enhance inflammatory responses which involve histamine and serotonin, including cell-mediated delayed-type hypersensitivity reactions. In this study we examined the effects of PTX on histamine-modulated microvascular responses. The actions of histamine on arteriole diameter and post-capillary leaky site formation in the cremaster muscle were measured intra-vitally in two inbred strains of mice (viz. BALB/c and SLJ). In SJL mice the rate and extent of histamine-induced leaky site formation were greatly enhanced (from 8.3 to 21.0 leaky sites per 0.1 cm2) by pre-exposure to PTX. In sharp contrast, PTX did not alter histamine-induced leaky site formation in BALB/c mice. Histamine-mediated dilation in arterioles in both strains of mice were not enhanced by PTX. PTX may enhance the development of inflammatory responses by enhancing histamine-induced leaky site formation of the microvasculature.
X-ray spectra of the Puppis A and the Vela supernova remnants

Low-energy X-ray spectra are presented for the entire Vela supernova remnant (SNR), the two most intense subregions of the Vela SNR, and the Puppis A SNR. Acceptable chi-squared fits are obtained from the model of a high-temperature low-density plasma with Allen cosmic abundances when thermal bremsstrahlung, radiative recombination, line emission, and interstellar absorption are included. A suggested increase of 45-fold in the Si abundance for the entire Vela SNR is found unacceptable by chi-squared tests of the present spectra. The two enhanced regions of Vela are found to have different temperatures. A deficiency of at least a factor of 3 is seen in the O VII and O VIII emission from the entire Vela SNR. Because ultraviolet observations indicate a normal abundance of oxygen, this is interpreted as evidence for the existence of nonequilibrium conditions in the emitting plasma.
The addiction of overeating: Self-help groups as treatment models

This article defines eating disorders and compares it to other addictions, gives a brief etiology, and presents two treatment models: Overeaters Anonymous and Weight Watchers International. The same personality factors that place individuals at risk for substance abuse are often found in individuals with eating disorders. These predispositions are explored from both a developmental and sociological perspective. Resources within our own communities can provide valuable interventions. Overeaters Anonymous emphasizes the psychological and spiritual components, with its main focus being the commitment to the group. Weight Watchers is also rooted in the fellowship of community but adopts a more behavioristic model. Although Weight Watchers supplies more practical strategies for managing overeating, both groups provide a framework for developing positive, adaptive, and self-nurturing modalities.
Fraunhofer diffraction pattern of apodized semicircular apertures

Abstract The far-field diffraction pattern of apodized semicircular apertures is described. The exact amplitude is given using incomplete cylinder functions. The paper also presents a simple approximation for the intensity that is suitable for further computations when the aperture is part of an optical system.
Optimal breathing protocol for dynamic contrast-enhanced MRI of solitary pulmonary nodules at 3 T

Abstract The purpose of this study was to evaluate optimal breathing maneuvers that minimize lung parenchymal movement for dynamic contrast-enhanced MRI (DCE-MRI), which requires longer scan times, beyond the limit of a single breath hold. A healthy volunteer was scanned on a 3 T MR scanner using two different breathing maneuvers. In the first, the healthy volunteer was instructed to hold his breath as much as possible and breathe in between breath holds while an image was obtained. In the second, the volunteer was instructed to breathe shallowly and freely throughout the scan. On the obtained images, the excursion of the highest point of the right diaphragm and the pulmonary vessel branches located in the four different anatomic regions of the lung were measured in two orthogonal planes. A patient with a solitary pulmonary nodule (SPN) underwent DCE-MRI utilizing a 2D spoiled gradient-echo (SPGR) sequence while the patient breathed shallowly and freely during the scan. The standard deviations of the excursion of the highest point and selected pulmonary vessels were much smaller during shallow, free breathing maneuver scans than those during breath hold maneuver scans. A dynamic perfusion-fitting curve of the SPN was obtained during the DCE-MRI using shallow free breathing. Shallow, free breathing allows smaller diaphragmatic cranial caudal and lung parenchymal displacements. Therefore, it can be useful during exams where targeting of the lesion is necessary, in studies with long scan times, such as dynamic MRI. This breathing maneuver makes it possible to analyze SPN with DCE-MRI while making use of the advantages of a higher magnetic field in conjunction.
Karst Interest Group 2011

The United States Geological Survey (USGS) Karst Interest Group (KIG) held its fifth triennial meeting at the University of Arkansas in Fayetteville, Arkansas, during April 26–29, 2011. After an interesting keynote presentation by Art Palmer on paleokarst of the USA, oral and poster presentations were given during 2-day sessions on a variety of topics, including karst in coastal zones, geochemistry and contaminant transport in karst systems, karst mapping and GIS, karst program updates, Ozarks plateau karst, karst aquifer systems, karst modeling, karst hydraulics, and geophysical methods in karst. There were 123 people registered for the meeting from government agencies, universities, state, and local agencies. Goals of the USGS KIG are to encourage and support interdisciplinary collaboration and technology transfer among scientists working in karst areas. The KIG encourages cooperative studies between the different disciplines of the USGS and other Department of Interior agencies and university researchers or research institutes. Previous KIG meetings were held in St. Petersburg, Florida (2001), Shepherdstown, West Virginia (2002), Rapid City, South Dakota (2005), and Bowling Green, Kentucky (2008). The next meeting is scheduled for 2014 in Carlsbad, New Mexico. For the 2011 meeting, field trips were organized on the geology and karst landscapes of the Buffalo National River and other karst features in northern Arkansas and southern Missouri. A good time was had by all, despite the recordbreaking rainfall and flooding prior to and during the first 2 days of the meeting. Proceedings from the 2011 KIG meeting have been published in the U.S. Geological Survey Scientific Investigations Report 2011-5031, which is available on-line at: http://pubs.usgs.gov/sir/2011/5031/. For additional information about KIG, please visit the KIG website at: http://water.usgs.gov/ogw/karst/kig/ or contact Eve Kuniansky (elkunian@usgs.gov) (770-409-7716).
Adsorption of Carbon Monoxide on Dendrimer-Encapsulated Platinum Nanoparticles: Liquid versus Gas Phase

The ability of dendrimer-encapsulated platinum nanoparticles (Pt DENs) to adsorb carbon monoxide was contrasted in the gas versus liquid phases by using in situ infrared absorption spectroscopy. It...
Social Cognition and Interpersonal Impairment in Young Adolescents with ADHD

The purpose of this study is twofold. First, it aims to examine whether the impairment in peer functioning and social-cognitive deficits (i.e., hostile attribution bias, social comprehension, social problem-solving) found in elementary school aged children with ADHD also occur in adolescence. Second, it aims to provide evidence for a predictive relationship between these social-cognitive deficits and an adolescent’s functional impairment in the social domain. To address these aims, several social-cognitive tasks were administered to a small sample of young adolescents with ADHD (N = 27) and a comparison sample without an ADHD diagnosis (N = 18). Parent report of functional impairment and peer sociometric data were also gathered. Comparisons of both parent and peer report of adolescent social functioning suggest that individuals with ADHD continue to experience difficulties with peers into the adolescent years and data from the social-cognitive tasks show evidence of social comprehension and problem-solving deficits. Further analyses indicated a significant link between functional impairment and social cognition. Findings herein are discussed in the context of both the developmental changes that arise during adolescence and consideration of the importance of social cognition for understanding the impaired social functioning experienced by adolescents with ADHD.
Numerical models of the primitive solar nebula.

The equations giving force balance in the radial and vertical directions in the primitive solar nebula are developed. The techniques used to compute the gravitational potential and to compute the opacity of the gas for energy transport in the vertical direction are described, as well as the properties of the primitive solar nebula models thus constructed. The rate at which gaseous dissipation should occur within the solar nebula, producing the sun by inward flow of matter, is discussed.
Role of integrin β1‐like protein in proliferation and differentiation of cultured stem cells from midgut of Heliothis virescens

Cultured midgut cells from Heliothis virescens larvae were incubated with anti-human integrin β1 made in rabbit and then passed over a column of magnetic beads bound to anti-rabbit IgG (MACS, Miltenyi Bergisch Gladbach, Germany). Cells bound to integrin β1 antibody also bound to the anti-rabbit IgG on the magnetic beads (MACS) and were retained in the column while it remained in the magnetic field. Non-bound cells were eluted at this time. They did not stain with anti-integrin antibody just after elution. Removing the column from the magnetic field allowed cells bound to the beads-integrin β1 antibody to be eluted. All of these cells stained with human anti-integrin β1 upon elution. Each cell fraction was cultured in medium for 3 days. During this time, the populations of cells tended to return to heterogeneous staining patterns characteristic of control populations. However, cells that did not stain immediately with anti-integrin β1 antibody exhibited double the rate of multiplication and 8 times more differentiation than the integrin-antibody positive cells that eluted later, as well as the non-treated control cells. In a second experiment, midgut cells were incubated for 4 days with various titers of human anti-integrin β1 to block surface integrin β1-like reactive sites. Stem cells blocked with anti-integrin β1 antibody during incubation exhibited double the rate of differentiation than non-treated control cells and those showing anti-integrin β1-positive stain upon elution. Arch. Insect Biochem. Physiol. 61:55–64, 2006. Published 2006 Wiley-Liss, Inc.
Vaccinia Virus mRNA (Guanine-7-)Methyltransferase: Mutational Effects on Cap Methylation and AdoHcy-Dependent Photo-Cross-Linking of the Cap to the Methyl Acceptor Site†

The (guanine-7-)methyltransferase domain of the vaccinia virus mRNA capping enzyme is composed of the C-terminal portion of the D1 subunit, D1(498-844), heterodimerized with the D12 protein. In order to identify protein structural elements involved in cap methylation, we introduced eight alanine substitution mutations within two sequence motifs of D1(498-844)-(594)VLAIDFGNG(602) and (681)IHYSF(685)--that are conserved in the cap methyltransferase from yeast. The D1(498-844)-Ala proteins were coexpressed in bacteria with the D12 subunit, and the recombinant D1(498-844)/D12 heterodimers were purified. Alanine substitutions at five positions--Asp-598, Gly-602, Ile-681, Ser-684, and Phe-685--had little or no effect on methyltransferase activity. Mutations at three conserved residues were deleterious. Alanine substitution at Gly-600 reduced the specific activity to 4% of that of the wild-type protein. Substitutions at His-682 and Tyr-683 reduced activity to 4% and 0.05%, respectively. By further mutating Tyr-683 to Phe and Ser, we established that the aromatic group was essential for cap methylation, whereas the hydroxyl moiety was dispensable. Specific binding of the methyltransferase to the RNA cap was demonstrated by UV cross-linking to [32P]GMP-labeled capped poly(A). Label transfer occurred exclusively to the D1(498-844) subunit and was competed by the cap analogs GpppA and m7GpppA. Cap-specific cross-linking to m7GpppA(pA)n was stimulated by AdoHcy, whereas cross-linking to GpppA(pA)n was unaffected by AdoHcy, but stimulated by AdoMet. We suggest that occupancy of the methyl donor site either enhances the affinity for the cap guanosine or alters the protein interface so that a photoreactive moiety is brought closer to the cap structure. The catalytically defective H682A, Y683A, and Y683S mutant methyltransferases were unable to cross-link to the cap in the presence of AdoHcy. The catalytically defective G600A mutant did cross-link to the cap in the presence of AdoHcy, suggesting that this mutation affects the chemical step of transmethylation.
Cyclooxygenase-2 is overexpressed in HER-2/neu-positive breast cancer: Evidence for involvement of AP-1 and PEA3

Markedly increased levels of cyclooxygenase-2 (COX-2) mRNA, protein, and prostaglandin E2synthesis were detected in HER-2/neu-transformed human mammary epithelial cells (184B5/HER) compared with its nontransformed partner cell line (184B5). HER-2/neu stimulated COX-2 transcription via the Ras → Raf → MAPK pathway. The inductive effects of HER-2/neu were mediated, in part, by enhanced binding of AP-1 (c-Jun, c-Fos, and ATF-2) to the cyclic AMP-response element (−59/−53) of the COX-2 promoter. The potential contribution of the transcription factor PEA3 was also investigated. Elevated levels of PEA3 were detected in 184B5/HER cells. A PEA3 site (−75/−72) was identified juxtaposed to the cyclic AMP-response element. HER-2/neu-mediated activation of the COX-2 promoter was blocked by mutagenizing the PEA3 site or overexpressing antisense to PEA3. To determine whether HER-2/neu status was also a determinant of COX-2 expression in vivo, we compared levels of COX-2 protein in HER-2/neu-positive and -negative human breast cancers. Increased amounts of COX-2 were detected in HER-2/neu-positive tumors. Taken together, these results suggest that closely spaced PEA3 and cyclic AMP-response elements are required for HER-2/neu-mediated induction of COX-2 transcription. The clear relationship between HER-2/neu status and COX-2 expression in human breast tumors suggests that this mechanism is likely to be operative in vivo.
The effectiveness of marine CO2 disposal

Abstract We consider the relative effectiveness of engineered systems for collection and marine disposal of CO2 from fossil-fuel-fired power plants using comparisons of the trend with time of CO2 concentration in the atmosphere from systems with and without marine disposal. Since the retention time for CO2 increases rapidly with depth of disposal, from a few years in the mixed layer up to several centuries as the depth increases beyond 1000 m, deep oceans have been considered as potential storage sites for CO2. However, CO2 collection and disposal consumes energy and produces extra CO2. We show that some of this extra CO2 reaches the atmosphere, so that atmospheric concentrations from systems with marine disposal ultimately exceed those from systems without controls. In some circumstances, they do so rapidly, making marine disposal less favorable than direct atmospheric release. The Global Warming Potential (GWP) can be used to compare different systems, but results for GWP highlight the difficult issue of determining what time scales are important in considering options to reduce concerns about global warming.
The Near-Appointment of Linus Pauling at the University of California, Santa Barbara

Linus Pauling, a Nobel Laureate in Chemistry, should have been a prize for any university. Yet, he was denied a position at the University of California, Santa Barbara, in 1964. His liberal activism apparently was too much for university officials to stomach; the McCarthy period still cast a dismal shadow.
Membrane-dependent conformational changes initiate cholesterol-dependent cytolysin oligomerization and intersubunit β-strand alignment

Cholesterol-dependent cytolysins are bacterial protein toxins that bind to cholesterol-containing membranes, form oligomeric complexes and insert into the bilayer to create large aqueous pores. Membrane-dependent structural rearrangements required to initiate the oligomerization of perfringolysin O monomers have been identified, as have the monomer-monomer interaction surfaces, using site-specific mutagenesis, disulfide trapping and multiple fluorescence techniques. Upon binding to the membrane, a structural element in perfringolysin O moves to expose the edge of a previously hidden β-strand that forms the monomer-monomer interface and is required for oligomer assembly. The β-strands that form the interface each contain a single aromatic residue, and these aromatics appear to stack, thereby aligning the transmembrane β-hairpins of adjacent monomers in the proper register for insertion. Collectively, these data reveal a novel membrane binding–dependent mechanism for regulating cytolysin monomer-monomer association and pore formation.
Bounds on the convex label number trees

A convex labelling of a tree is an assignment of distinct non-negative integer labels to vertices such that wheneverx, y andz are the labels of vertices on a path of length 2 theny≦(x+z)/2. In addition if the tree is rooted, a convex labelling must assign 0 to the root. The convex label number of a treeT is the smallest integerm such thatT has a convex labelling with no label greater thanm. We prove that every rooted tree (and hence every tree) withn vertices has convex label number less than 4n. We also exhibitn-vertex trees with convex label number 4n/3+o(n), andn-vertex rooted trees with convex label number 2n +o(n).
Enhanced device performance of GaInN-based deep green light emitting diodes with V-defect-free active region

We have performed the epitaxial growth of GaInN based deep green (540–570 nm) light emitting diodes (LEDs) by introducing processes to avoid the formation of V-defects in the active region of the GaInN/GaN multiple quantum wells. For 541 and 559 nm LED wafers, the light output power (LOP) at 90 A/cm2 reaches as high as 14 and 8 mW, respectively. These values are 4 times larger than those of typical deep green LED wafers with average V-defect density of 2–5 × 108cm–2. Under pulsed operation (pulse width of 50 μs, duty cycle 1%), the external quantum efficiency exhibits a maximum of 39% at 16 A/cm2 in 558 nm LED die of size (350 μm)2. This type of V-defect-free LED die also shows excellent lifetime behaviour. In 168 hr stress test of 30 mA at 80 °C, LOP declines less than 5%. Apparently, eliminating V-defects from the active region significantly enhances the reliability of deep green LEDs. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Implications of Mobility Impairment on the Diagnosis and Treatment of Breast Cancer

Abstract Background: Among women with chronic, preexisting mobility impairments, we sought to explore how their mobility difficulties affected the diagnosis and treatment of early-stage breast cancer Methods: This is a qualitative analysis of transcripts from in-depth in-person or telephone interviews with 20 English-speaking women who had early-stage breast cancer, were <60 years of age, and had chronic difficulty walking or used wheeled mobility aids at the time of their breast cancer diagnoses Results: Nine women were disabled by polio as children or had postpolio syndrome, 3 had cerebral palsy, 3 had spinal cord injury, and 5 had other conditions. Most women reported difficulty obtaining mammograms, primarily because of inaccessible equipment, positioning problems, and difficulties with uncontrollable movements. Many women made decisions about surgical approach and chemotherapy by explicitly considering how various therapies would affect their arms, which are essential to their mobility (they use ambu...
Recent advances of tissue culture in cancer research.

On donne ici un bref expose des principaux courants d'idee qui se rattachent surtout a la recherche anticancereuse telle qu'elle a ete abordee depuis la seconde guerre modiale par la methode des cultures de tissus. De grands progres techniques ont aujourd'hui rendu possible la manipulation en masse de la cellule de mammiferes en cultures continues, cellule traitee essentiellement comme microorganisme. Toutefois, comme les cellules a croissance rapide autant d'origine normale que maligne perdent leurs caracteres individuels et finissent par se ressembler, l'interet se reporte actuellement sur les cultures de tissus organises, ou les facteurs favorables a la differenciation et au controle de la croissance peuvent etre examines.
Patellar nomenclature: the Tower of Babel revisited.

Because we communicate mainly through words, it is important that terms be understood in the same manner by all readers. Unfortunately, the study of the patellofemoral joint is complicated by the use of expressions that hold different meanings for different readers. Ideally, the community of musculo
Best Constants for Uncentred Maximal Functions

We precisely evaluate the operator norm of the uncentred Hardy–Littlewood maximal function on L p (ℝ 1 ). Consequently, we compute the operator norm of the ‘strong’ maximal function on L p (ℝ n ), and we observe that the operator norm of the uncentred Hardy–Littlewood maximal function over balls on L p (ℝ n ) grows exponentially as n [xrarr ]∞.
Vesicular transport earns a Nobel

The field of intracellular traffic is celebrating the awarding of the 2013 Nobel Prize in Physiology or Medicine to three of its most distinguished scientists – James Rothman, Randy Schekman, and Thomas Sudhof – for their discoveries on the molecular mechanisms of vesicular transport. Their outstanding achievements serve as inspiration for the next generation of scientists to continue the task of uncovering new principles of intracellular compartmentalization and dynamics.
Interview with Dr Rosalie Tung: a cross-cultural studies researcher and published author

Purpose – This interview was conducted with Dr Rosalie Tung. Dr Tung gives her insight about her career. Design/methodology/approach – Interview was conducted via Skype. There was a somewhat systematical approach to the Q&A interview. Findings – Dr Tung briefly goes through her academic career regarding cross-cultural studies and how her life experiences shaped her passion for the subject. Originality/value – This was a one-on-one interview via Skype.
Fractional sublimation of various metal acetylacetonates

Abstract A simple fractional sublimator is described which possesses a continuous temperature gradient along its length. Samples are placed in the high temperature end of the tube and volatilized at 1-mm pressure. The gases are moved through the tube with air as a carrier. The metal chelates recrystallize on the walls of the tube in discrete and reproducible temperature zones. Characteristic recrystallization zones are reported for 21 metal acetylacetonates. The chelates can be grouped according to zone temperatures into 6 fairly distinct groups over the range 15 to 200°, which makes many separations possible. Separations of mixtures of Mg, Al and Be ; Ni, Fe and Be ; and, Cu and Fe were studied quantitatively. The separations achieved compared favorably with those reported by gas chromatography. The method offers real promise for the purification of a number of metals but appears especially good as a method for beryllium and certain platinum group metals.
Two forms of the 6/sec spike and wave complex

In 3 decades 1550 patients showed 6/sec spike and wave complexes; 839 were chosen for computer-analyzed electroclinical correlations. Control groups (each 500) included patients (1) randomly selected from EEG files, (2) with normal EEGs, (3) with only slow wave abnormalities, and (4) with only spike abnormalities. In the experimental group more females and Caucasians were found with peak age distribution at 11--15 years. The major symptoms were seizures (53%), neurovegetative (51%) and psychological complaints (24%), all significantly different from control groups, except for seizures in control group 4. Seizures were mainly generalized motor attacks, neurovegetative symptoms included headaches, dizziness and blackouts and psychological symptoms were mainly behavior disorders. As a presumed etiology head injury was noted in over 25% with this complex, which was maximal either on the anterior or occipital areas. Further computer analysis shows that two extreme forms can be identified: (1) the WHAM form, seen mainly in waking records, high amplitude, anterior location, more males, and (2) the FOLD form, seen mainly in females, occipital location, low amplitude, in drowsy states. The WHAM form appears primarily in patients with seizures, and the FOLD form in patients with neurovegetative and psychological complaints.
Preparation and Characterization of Chiral Copper 12-Metallacrown-4 Complexes, Inorganic Analogues of Tetraphenylporphyrinatocopper(II).

Chiral 12-metallacrown-4 complexes can now be obtained in high yield using resolved β-phenylalanine hydroxamic acids as organic scaffolding. These new copper(II) compounds bear a striking resemblance based on size and shape to Cu(II) tetraphenylporphyrin. This suggests that metallacrowns may be useful alternatives to metalloporphyrins in future applications which require high metal densities and well-defined chiral centers.
Suppressor T cells prevent in vitro expression of IgM rheumatoid factor in some healthy adults

Peripheral blood mononuclear leukocytes (MNL) from 11 of 30 healthy adults elaborated detectable IgM RF when stimulated with pokeweed mitogen. The influence of T cells on IgM RF production by autologous B Cells prepared from donors whose unfractionated MNL synthesized IgM RF in response to PMW was investigated. Untreated T cells supported IgM RF production by autologous B cells with optimal synthesis observed at T:B cell ratios of 2:1 at higher T:B cell ratios a decline in IgM RF production occurred. In contrast, at higher T:B cell ratios irradiated T cells supported consistently higher levels of IgM RF production than untreated T cells suggesting the presence of radiosensitive suppressor T cells for IgM RF in these individuals. Irridiated T cells were compared to untreated T cells for capacity to support IgM RF production by autologous B cells from 12 randomly selected donors at T:B cell ratios of 3:1. Untreated T cells from 4 of 12 individuals were capable of cooperating in induction of IgM RF production by autologous B cells, whereas irradiated T cells supported IgM RF production in 6 of 12 individuals. Levels of IgM RF production in all 6 individuals were significantly higher with irradiated T cells thanmore » with untreated T cells; in 2 individuals IgM RF synthesis by autologous B cells was observed only in the presence of irradiated T cells. In 4 of 6 individuals increases in the ratio of IgM RF total IgM synthesis occured with irradiated T cells (when compared to untreated T cells), suggesting disproportionate suppression of RF production. These results indicate the presence of radiosensitive T cells capable of suppressing IgM RF production in a significant fraction of healthy adults and raise the possibility that these cells may regulate in vivo expression of RF.« less
Dynamically-tuned microresonator complexes

Dynamic tuning of systems of microresonators coupled to waveguides allows a rich range of physical effects. Periodic resonator arrays can be tuned to stop and store light pulses, theoretically allowing for tunable delay devices in which the delay is limited neither by bandwidth nor by dispersion. For two-resonator systems, adjustable delays can be obtained from tuning a narrow transparency resonance. Similar behavior is also predicted in a quite different physical system, that of a single photon interacting with dynamically-tuned quantum bits.
On minor-minimally-connected matroids

Abstract By a well-known result of Tutte, if e is an element of a connected matroid M , then either the deletion or the contraction of e from M is connected. If, for every element of M , exactly one of these minors is connected, then we call M minor-minimally-connected. This paper characterizes such matroids and shows that they must contain a number of two-element circuits or cocircuits. In addition, a new bound is proved on the number of 2-cocircuits in a minimally connected matroid.
Improving Sparse Network Seismic Location with Bayesian Kriging and Teleseismically Constrained Calibration Events

Monitoring the Comprehensive Nuclear-Test-Ban Treaty will require improved seismic location capability for small-magnitude events. The International Monitoring System (IMS) is well suited to locate events that are large enough to be recorded at teleseismic distances. However, small events are likely to be recorded on a sparse subset of IMS stations at regional- to upper-mantle distances (less than 30°), and sparse-network locations can be strongly effected by travel-time errors that result from path-specific velocity model inaccuracies. In an effort to improve sparse network location capability, we outline a procedure that applies empirical corrections to travel times determined with an appropriate velocity model. More specifically, Bayesian kriging and calibration events (constrained with a global network) are used to estimate epicenter-specific travel-time corrections. For a test (sparse) network of stations, we calculate travel-time residuals for the calibration events relative to the ak135 velocity model. Travel-time residuals are assigned to the respective calibration epicenter, forming a set of spatially varying travel-time correction points. The spatial set of correction points is declustered to reduce the dimension of the observations with minimal reduction in accuracy of the travel-time corrections. We then use the declustered set of calibration points and Bayesian kriging to form continuous travel-time correction surfaces for each station of the test network. The effectiveness of travel-time correction surfaces is evaluated by locating, with and without corrections, a subset of the 1991 Racha earthquake sequence (Caucasus Mountains), for which we have accurate locations that were independently determined with a dense local network. When no travel-time correction is applied, the mean horizontal distance between the local and test network locations is 42 km, and there is a distinct bias in sparse-network locations toward the north-northwest. The mean difference between local and sparse network locations is cut to 13 km when corrections are applied, and the bias in location is significantly reduced. When calibration events in the Racha vicinity are not used to make the correction surfaces, there is still a significant improvement in location, with mean mislocations of 15 km. When corrections are not applied, only one of the locally determined locations lies within the associated 90% coverage ellipse determined with the test (sparse) network. However, by using travel-time corrections and estimates of model uncertainty determined using kriging, representative error ellipses are obtained. This study demonstrates that kriging correction surfaces based on global-network-constrained calibration events can improve the ability to accurately locate lower magnitude events while providing representative coverage ellipses.
A brief note examining the impact of federal deposit insurance on savings and loan failures using granger causality tests

This brief note applies Granger causality testing to the issue of whether federal deposit insurance has caused S&L failures. The findings strongly indicate that federal deposit insurance has Granger-caused S&L failures over the 1934–1991 period.
Temperature-regulated expression of bacterial virulence genes

Virulence gene expression in most bacteria is a highly regulated phenomenon, affected by a variety of parameters including osmolarity, pH, ion concentration, iron levels, growth phase, and population density. Virulence genes are also regulated by temperature, which acts as an 'on-off' switch in a manner distinct from the more general heat-shock response. Here, we review temperature-responsive expression of virulence genes in four diverse pathogens.
The role of taste preference in the eating behavior of the albino rat

The effects of adding flavoring substances to a standard wet mash diet were tested on twelve male albino rats. The diets, presented singly for ten days each, were 0.15 per cent saccharin sodium, H2O alone, 0.0375 per cent, 0.075 per cent and 0.12 per cent quinine sulfate. Animals showed intake differences related to diet palatability. Although these differences decrease progressively for the first 8 days there is some evidence that asymptotic steady-state intake would be different for the different diets. Even in the case of achievement of iso-caloric intake across diets, the animal does not ignore taste. This is demonstrated by significant changes in meal-taking which are not attributable solely to total intake differences and, in fact, are greatest at the time that total intake differences are smallest. Specifically, meal size and intermeal-interval size increase as the diet is made less palatable. This change may be necessary for the achievement of stable iso-caloric intake across the diets used in the present experiment. Some implications for finicky animals are discussed.
TREATMENT OF EARLY RECURRENT PROSTATE CANCER WITH 1,25-DIHYDROXYVITAMIN D3 (CALCITRIOL)

AbstractPurpose: Substantial experimental and epidemiological data indicate that 1,25-dihydroxy-vitamin D3 (calcitriol) has potent antiproliferative effects on human prostate cancer cells. We performed an open label, nonrandomized pilot trial to determine whether calcitriol therapy is safe and efficacious for early recurrent prostate cancer. Our hypothesis was that calcitriol therapy slows the rate of rise of prostate specific antigen (PSA) compared with the pretreatment rate.Materials and Methods: After primary treatment with radiation or surgery recurrence was indicated by rising serum PSA levels documented on at least 3 occasions. Seven subjects completed 6 to 15 months of calcitriol therapy, starting with 0.5 micro g. calcitriol daily and slowly increasing to a maximum dose of 2.5 micro g. daily depending on individual calciuric and calcemic responses. Each subject served as his own control, comparing the rate of PSA rise before and after calcitriol treatment.Results: As determined by multiple regress...
Accuracy Analysis of a Spectral Element Atmospheric Model Using a Fully Implicit Solution Framework

Abstract A fully implicit (FI) time integration method has been implemented into a spectral finite-element shallow-water equation model on a sphere, and it is compared to existing fully explicit leapfrog and semi-implicit methods for a suite of test cases. This experiment is designed to determine the time step sizes that minimize simulation time while maintaining sufficient accuracy for these problems. For test cases without an analytical solution from which to compare, it is demonstrated that time step sizes 30–60 times larger than the gravity wave stability limits and 6–20 times larger than the advective-scale stability limits are possible using the FI method without a loss in accuracy, depending on the problem being solved. For a steady-state test case, the FI method produces error within machine accuracy limits as with existing methods, but using an arbitrarily large time step size.