cssi/SciSciGPT-SciSciNet huggingface dataset:
A specification-based approach to reasoning about pointers

This paper explains how a uniform, specification-based approach to reasoning about component-based programs can be used to reason about programs that manipulate pointers. No special axioms, language semantics, global heap model, or proof rules for pointers are necessary. We show how this is possible by capturing pointers and operations that manipulate them in the specification of a software component. The proposed approach is mechanizable as long as programmers are able to understand mathematical specifications and write assertions, such as loop invariants. While some of the previous efforts in reasoning do not require such mathematical sophistication on the part of programmers, they are limited in the kinds of properties they can prove about programs that use pointers. We illustrate the idea using a "Splice" operation for linked lists, which has been used previously to explain other analysis techniques. Not only can the proposed approach be used to establish shape properties given lightweight specifications, but also it can be used to establish total correctness given more complete specifications.
Degenerate Perturbation Theory

The algebraic structure of degenerate Rayleigh-Schroedinger perturbation theory is reviewed. There are a number of different but equivalent algorithms which generate this perturbation series; we argue that the frequent need to carry out infinite-order partial summations selects one of these algorithms as the most efficient. Recent developments include coupled-cluster formulations for open shells, a new diagrammatic representation, and the concept of incomplete model subspaces. These subjects are reviewed, as well as some applications.
Presence of a pseudo-gap feature in the density of states of disordered W/Si alloys

Abstract One of the most striking features of the high-temperature superconducting cuprates is the presence of a gap-like structure in the density of states above the superconductive transition temperature, Tc. Analysis of conductance data from point-contact tunneling measurements on disordered W/Si thin films shows the presence of similar gap-like features above Tc. Details of the film growth and characterization are presented. A phase diagram which includes Tc and a pseudo-gap temperature, T*, are presented.
Hydrophobic salt-modified Nafion for enzyme immobilization and stabilization.

Over the last decade, there has been a wealth of application for immobilized and stabilized enzymes including biocatalysis, biosensors, and biofuel cells.1-3 In most bioelectrochemical applications, enzymes or organelles are immobilized onto an electrode surface with the use of some type of polymer matrix. This polymer scaffold should keep the enzymes stable and allow for the facile diffusion of molecules and ions in and out of the matrix. Most polymers used for this type of immobilization are based on polyamines or polyalcohols - polymers that mimic the natural environment of the enzymes that they encapsulate and stabilize the enzyme through hydrogen or ionic bonding. Another method for stabilizing enzymes involves the use of micelles, which contain hydrophobic regions that can encapsulate and stabilize enzymes.4,5 In particular, the Minteer group has developed a micellar polymer based on commercially available Nafion.6,7 Nafion itself is a micellar polymer that allows for the channel-assisted diffusion of protons and other small cations, but the micelles and channels are extremely small and the polymer is very acidic due to sulfonic acid side chains, which is unfavorable for enzyme immobilization. However, when Nafion is mixed with an excess of hydrophobic alkyl ammonium salts such as tetrabutylammonium bromide (TBAB), the quaternary ammonium cations replace the protons and become the counter ions to the sulfonate groups on the polymer side chains (Figure 1). This results in larger micelles and channels within the polymer that allow for the diffusion of large substrates and ions that are necessary for enzymatic function such as nicotinamide adenine dinucleotide (NAD). This modified Nafion polymer has been used to immobilize many different types of enzymes as well as mitochondria for use in biosensors and biofuel cells.8-12 This paper describes a novel procedure for making this micellar polymer enzyme immobilization membrane that can stabilize enzymes. The synthesis of the micellar enzyme immobilization membrane, the procedure for immobilizing enzymes within the membrane, and the assays for studying enzymatic specific activity of the immobilized enzyme are detailed below.
Genetic algorithm stopping criteria for optimization of construction resource scheduling problems

Genetic algorithms (GAs) have been widely applied in the civil and construction engineering management research domain to solve difficult and complex problems such as resource-constrained project scheduling problems (RCPSPs). Generally, a trial-and-error calibration approach is used to identify values for the GA parameters. Unlike with other parameters, few studies have been done, theoretically or experimentally, for determining when to terminate GA for optimization of the RCPSP. Two genetic algorithm stopping conditions are compared to demonstrate their suitability for application in the RCPSP and to assess their ability in searching optimal solutions efficiently. The extensive computational results show that the Elitist GA, when using the unique schedule method, provides 10% more optimum values than those obtained from the Elitist GA when using the iteration method with 24% less computational time. The unique schedule stopping approach can be valuable for GA users to design their purpose driven GA for o...
The muskrat (Ondatra zibethicus) as a laboratory animal

Methods for the capture, maintenance, taming, and behavioral testing of wild-born muskrats(Ondatra zibethicus) are described. The muskrat is simple and inexpensive to maintain in the laboratory and seems suitable for behavioral research.
Stimulation of peroxidase reactions by hydroxamates

Salicylhydroxamic acid, benzohydroxamic acid, and phenylacetohydroxamic acid were found to stimulate the oxidation of NADH, dithiothreitol, and ferrocyanide by horseradish peroxidase. The hydroxamates themselves served as substrates in peroxidase reactions, and the observed stimulations may involve hydroxamate free-radical formation.
N-Myc Down-regulated Gene 1 Modulates the Response of Term Human Trophoblasts to Hypoxic Injury

The placenta is susceptible to diverse insults during human pregnancy. The expression of the protein N-myc down-regulated gene 1 (NDRG1) is regulated during cell proliferation, differentiation, and in response to stress. Nevertheless, the function of this protein in humans remains unknown. We tested the hypothesis that NDRG1 is up-regulated in hypoxic primary human trophoblasts and that NDRG1 modulates trophoblast response to hypoxia. We initially demonstrated that the expression of NDRG1 is enhanced in primary human trophoblasts exposed to hypoxia. Importantly, we found a similar increase in NDRG1 expression in placental samples derived from either singleton gestations complicated by intrauterine growth restriction or from dizygotic twin gestation where one twin exhibited growth restriction. Having established efficient lentivirus-mediated transfection of primary human trophoblasts, we overexpressed NDRG1 in trophoblasts, which resulted in enhanced trophoblast differentiation. In contrast, lentivirus-driven short interfering RNA-mediated silencing of NDRG1 diminished trophoblast viability and differentiation. Consistent with these results, NDRG1 reduced the expression level of p53 in trophoblasts cultured in standard or hypoxic conditions. Furthermore, NDRG1 expression was regulated by the activity of SIRT1 (Sir2-like protein 1), which promotes cell survival. Together, our data indicate that NDRG1 interacts with SIRT1/p53 signaling to attenuate hypoxic injury in human trophoblasts.
White-dwarf variability and the rotation of g-modes

The multiperiodic behavior clearly evident after Fourier analysis of many DA white-dwarf light curves is interpreted as arising from outbursts whose timing is regulated by the rotation and oscillation of the star. A model is proposed on the basis of three main assumptions: (1) a broad array of g-mode oscillations is taking place all the time in DA white-dwarf variables; (2) slow rotation permits most of the g-modes to couple and form a small group of nonlinear modes, each characterized by one of the indices of the spherical harmonic functions involved; and (3) the observed brightenings of the star are produced by upwelling of convection on a large horizontal scale when the antinodes of the nonlinear oscillation patterns periodically rotate into alignment and cause a temporary local enhancement of energy per unit volume. This model is used to match precisely almost every strong periodicity observed in the complex light curves of the DA white dwarfs G207-9, G38-29, G29-38, and HL Tau 76. If the model has been applied correctly, the results indicate that all four of these variables are rotating slowly with periods in the range from 250 to 500 sec.
Conceptual phase diagram and its application to the spontaneous magnetism of several pyrites

Abstract A one-electron energy diagram is constructed for FeS 2 , and its modification for CoS 2 and NiS 2 are discussed. A T - n l - b phase diagram is constructed, where n l gives the occupancy of the narrow σ∗ band determined by chemistry and b ∼ ϵλ σ is proportional to the width of the narrow σ∗ band in the itinerant-electron domain. Here ϵ is a one-electron energy and λ σ is the e g -( sp 3 ) covalent-mixing parameter for σ-bonding orbitals. These two diagrams are used to interpret the varied magnetic properties of the systems Fe 1− x Co x S 2 , Co 1− x Ni x S 2 , CoS 2− x Se x , and CoS 2− x As x . In the mixed systems, the σ∗ bands must be separated into donor and acceptor bands, and it is shown how this may be done for each system. The ferromagnetic to antiferromagnetic transition in CoS 2− x Se x is attributed to the appearance of a spin-density wave in the narrow transitional range of b between full-moment ferromagnetism ( μ Co = 1 μ B ) and Pauli paramagnetism.
Syntheses and structures of mono-thiocyanate complexes of cadmium(II) and lead(II) containing bulky nitrogen based polydentate ligands

Abstract The reaction of [Cd2(thf)5](BF4)4 with two equiv. of Tl[HB(3-Butpz)3] (pz=pyrazolyl ring) produces the intermediate {[HB(3-Butpz3]Cd}[BF4] that reacts with potassium thiocyanate to yield [HB(3-Butpz)3]Cd(NCS) (1). The solid state structure shows that the sterically demanding 3-tert-butyl groups enforce the formation of a tetrahedral, monomeric complex, the first four-coordinate cadmium(II)-thiocyanate complex to be structurally characterized. The decomposition of this compound produced [(ButHpz)2Cd(NCS)2]n (2) as shown by X-ray crystallography. It was not possible to form a lead(II) complex analogous to 1, but using less sterically demanding ligands allowed the preparation of {[HB(3,5-Me2pz)3]Pb(μ-NCS)}2 (3), and {[HB(pz)3]Pb(μ-NCS)}n (4). The former has a dimeric structure with both μ-NCS-S,N and μ-NCS-S,S bridging SCN− ligands and the latter has a infinite 2-D layered array in which three nonequiv. {[HB(pz)3]Pb}+ groups sandwich a layer of SCN− ligands. Using neutral 2,6-pyridyl-diimine ligands (pydim) having bulky 2,6-dimethylphenyl substituents, parallel complexes of both metals were prepared. The cadmium complex, [(pydim)Cd (NCS)]2[BF4]2 (5) is dimeric with normal μ-NCS-S,N bridging groups. The structure of the lead(II) analog, [(pydim)Pb(NCS)][BF4] (6) is monomeric with an N-bound, isothiocyanate ligand and a four-coordinate lead(II). The structure of 6 is very different from 5, presumably because of the stereoactive lone pair on lead(II).
Total Hip Arthroplasty After Failed Operative Treatment for Osteonecrosis of the Femoral Head

Of the numerous total hip arthroplasties performed each year for end-stage osteoarthritis a significant number are done in patients who suffer from osteonecrosis of the femoral head. Many of those patients have had a previous surgical treatment in an attempt to preserve the joint and to delay the need for a total hip arthroplasty. These treatments include core decompression with or without bone grafting, proximal femoral osteotomies, and free vascularized bone grafting. Each of these procedures, however, changes the anatomy of the proximal femur and present unique challenges to the orthopedic surgeon attempting to perform a subsequent total hip arthroplasty. Here we discuss the specific pitfalls in performing a total hip arthroplasty after a joint-sparing/preserving procedure and specific strategies with which to deal with each of them.
The Theory of Planned Behavior and Intention to Repeat Mammography Among African-American Women

Abstract Because minority women remain underusers of mammography screening, strategies to increase preventive health behavior may involve affordable screening as well as cultural determinants. Most studies have used a theoretical model inconsistently to assess characteristics, such as attitudes, beliefs, and perceptions about adherence to screening, whereas other studies have lacked sociocultural dimensions that may be relevant in promoting repeat screening in certain populations. This two-phase study examined adherence to mammography screening among 150 African-American women aged 40 to 49 years who had received one to five mammograms. Phase I included an elicitation procedure, a focus group, and pretests as steps in constructing a telephone interview. In Phase II, 150 telephone interviews were completed. Women's intentions regarding repeat mammography screening were assessed using the theory of planned behavior, expanded to include socio-cultural, religious, and psychological variables. Only the attitud...
Advertising Attitudes in West Germany and the U.S.: An Analysis over Age and Time

Results of a cross-cultural, repeated measures study of advertising attitudes among subscribers toward product test magazines are presented. The subscribers, seen as an important group of purchasers and trend setters, are found to have less favorable attitudes to all aspects of advertising studied in 1976 than in 1970, both in the U.S and West Germany. Differences in attitudes among age groups are much more clearly structured in 1976, with younger subscribers showing consistently lower attitudes. Differences are found between countries, particularly in varied views of economic and social dimensions. Implications are discussed and future research suggested.
The Role Of FT-IR In The Identification Of Domoic Acid, A New Shellfish Toxin

A brief but serious outbreak of poisoning by mussels occurred in Canada in December 1987. In a round-the-clock effort, the toxin that caused this outbreak was isolated in our laboratory and identified as domoic acid, a naturally-occurring substance that had not previously been reported to cause human poisoning. The identification of the toxin was achieved by the concerted use of spectroscopic methods, among them micro-FT-IR spectroscopy. The use of the FT-IR microscope allowed high-quality infrared spectra to be obtained on sub-microgram quantities of the early isolates of the toxin. The microscopic method had an additional advantage in that it enabled us to carry out a rough but rapid separation of the compound of interest from admixtures of unrelated substances by recording the spectra of a gradually dried out drop of solution on a microscope plate. Following the positive identification of the toxin as domoic acid, a detailed spectroscopic study was made of this important molecule in its several isomeric forms.
Site-Specific Fabrication and Epitaxial Conversion of Functional Oxide Nanodisk Arrays

Nanodisk arrays of technologically important magnetic (CoFe2O4) and ferroelectric (BaTiO3) oxides are fabricated on diverse substrates with well-defined size and separation using the soft-eBL approach. We demonstrate that below a certain pattern size, the as-deposited amorphous nanodisks can be readily converted into dense, single-crystal form that exhibit cube-on-cube heteroepitaxy with respect to the underlying single-crystal substrate. Such single-crystal disks show well-defined truncated-pyramid morphology that is consistent with Wulff construction. The mechanism of morphology development with the pattern size change is discussed. Localized characterization of the crystallinity, chemical composition, and magnetic behavior of the CFO nanodisk patterns are carried out using analytical transmission electron microscopy and magnetic force microscopy. Such solution-based epitaxial conversion of patterned arrays of multifunctional oxides has potential for viable cost-effective technological applications.
Old woman creek, Ohio: The designation of a freshwater estuarine sanctuary

The Ohio Department of Natural Resources and the U.S. Office of Coastal Zone Management have proposed the Old Woman Creek estuary on Lake Erie as the nation's first freshwater estuarine sanctuary. Designation as an estuarine sanctuary will preserve 637 acres of marshland, sand bar, a barrier beach, and surrounding forested uplands for public education and research. The original January 1975 grant application required modification following local residents’ objections to purchases of highly productive farmland and land‐use controls on a watershed‐wide buffer zone. A federal grant award was made in July 1977, with full acquisition anticipated by the end of 1978.
MetR-mediated repression of the glyA gene in Escherichia coli

Inactivation of either of the two MetR binding sites centered at bp —143 and —121 relative to the +1 transcription start site results in reduced glyA-lacZ expression in a wild-type strain below the level seen in a metR mutant. This reduced expression is dependent on the side of the DNA helix MetR binds relative to the RNA polymerase binding site. Thus, a single MetR dimer bound to the DNA may play a physiological role in maintaining appropriate glyA gene expression, functioning as a represser under low MetR conditions.
Use of Diffusion Tensor Imaging in the Resection of Gliomas

Standard magnetic resonance imaging techniques provide only anatomic information without information regarding central nervous system connectivity. Overcoming this limitation, diffusion tensor imaging (DTI) can demonstrate the structural integrity and white matter tracts of the brain. In this paper, we will overview the basic principles and techniques of DTI. We will also review the application of DTI in neurosurgery, particularly its application in the resection of gliomas. Tractography provides visualization of the motor tracts and language tracts, which has been corroborated using subcortical mapping/direct stimulation. Furthermore, DTI can also provide information about the arrangement of visual fibers in relation to tumors. Given these advantages, DTI is becoming increasingly used as a surgical planning tool. DTI may provide a safer means for tumor resection by minimizing iatrogenic injury of important functional tracts. Some studies suggest that the use of DTI in tumor surgery may lead to greater Karnofsky performance status scores, greater extent of tumor resection, and increased overall survival.
Origin of the anatase to rutile conversion of metal-doped TiO 2

Extensive calculations using density functional theory enable us to explain the origin of the surprising room-temperature conversion of anatase to rutile phase of ${\text{TiO}}_{2}$ when doped with Co and Ni, but not with Cu. Contrary to earlier suggestion, neither high spin nor strain of the transition metals is found to be responsible for this phase conversion. The driving mechanism, instead, is attributed to the increased interaction between Co and Ni atoms forming a linear chain in the rutile phase. We predict that Cr and Mn which have even larger spins than Co and Ni cannot induce this phase conversion.
Effects of systemic pancreastatin on memory retention.

Abstract Pancreastatin, a peptide isolated from the pancreas, was shown to enhance memory retention after peripheral administration in mice when administration following T-maze footshock avoidance training. The effect of pancreastatin on memory retention, one week after training, was time dependent showing enhancement of retention when pancreastatin was administered 0 and 30 min but not 60 min after training. Pancreastatin reversed the amnesia produced by scopolamine. The pancreastatin fragment (33–49) also enhanced memory. Pancreastatin did not increase glucose in vivo. We conclude that peripherally administered pancreastatin modulates memory processing.
Antiplane vibration of an elastic layer with a midplane crack

The oscillations of an elastic layer excited by antiplane tractions of uniform intensity along the faces of a midplane crack are investigated. A singular integral equation is derived and solved numerically by Gauss-Chebyshev integration technique. The stress intensity factor and crack surface response are computed as functions of frequency and layer thickness-to-crack length ratio, and the resonant frequencies of the cracked layer are determined.
Peritoneal macrophages from patients with endometriosis release growth factor activity in vitro.

We studied the in vitro secretion of macrophagederived growth factor (MDGF) activity by peritoneal macrophages from fertile and infertile women. Peritoneal fluid was obtained from 55 women undergoing laparoscopy for evaluation and treatment of infertility or for tubal sterilization. Isolated macrophages were plated in tissue culture wells and incubated in Dulbecco's Modified Eagle's Medium plus 0.2% lactalbumin hydrolyzate at 37 C for 24 h. Medium MDGF activity was assayed by determining the ability of medium to stimulate [3H] thymidine incorporation in BALB-c 3T3 fibroblasts. Macrophages from 23 women released significant MDGF activity in vitro; the release was linear for up to 72 h. Among the 55 women, macrophages from 10 of 36 (28%) women with normal pelvic anatomy or tubal occlusion/pelvic adhesions released significant MDGF activity. In contrast, macrophages from 13 of 19 (68%) women with endometriosis, a significantly higher proportion (P < 0.02), released MDGF. The finding that endometriosis is ass...
Robust media processing on programmable power-constrained systems

To achieve consumer-level quality, media systems must process continuous streams of audio and video data while maintaining exacting tolerances on sampling rate, jitter, synchronization, and latency. While it is relatively straightforward to design fixed-function hardware implementations to satisfy worst-case conditions, there is a growing trend to utilize programmable multi-tasking solutions for media applications. The flexibility of these systems enables support for multiple current and future media formats, which can reduce design costs and time-to-market. This paper provides practical engineering solutions to achieve robust media processing on such systems, with specific attention given to power-constrained platforms. The techniques covered in this article utilize the fundamental concepts of algorithm and software optimization, software/hardware partitioning, stream buffering, hierarchical prioritization, and system resource and power management. A novel enhancement to dynamically adjust processor voltage and frequency based on buffer fullness to reduce system power consumption is examined in detail. The application of these techniques is provided in a case study of a portable video player implementation based on a general-purpose processor running a non real-time operating system that achieves robust playback of synchronized H.264 video and MP3 audio from local storage and streaming over 802.11.
Domino intramolecular enyne metathesis/cross metathesis approach to the xanthanolides. Enantioselective synthesis of (+)-8-epi-xanthatin

Abstract The first total synthesis of (+)-8- epi -xanthatin ( 1 ) has been achieved in 14 steps starting from the commercially available ester 24 , which was converted into aldehyde 23 in six steps. An enantioselective aldol reaction of 23 gave 30 , which was transformed into triflate 22 in four steps, setting the stage for a palladium-catalyzed carbonylation reaction to form acrylate 34 . Compound 34 was then subjected to a deprotection/lactonization sequence to furnish enyne 21 , which underwent a domino enyne ring-closing metathesis/cross metathesis process to form a seven-membered carbocycle and ( E )-conjugated dienone, thereby completing the synthesis of 1 . This domino ruthenium-catalyzed metathesis reaction thus serves as an efficient method to construct the core of xanthanolide and other sesquiterpene lactones.
Dipole polarizabilities of Zn, Cd, and Hg (1S)

Abstract Relativistic effective core potential calculations of the dipole polarizabilities (α D ) for ground state Zn, Cd and Hg atoms give the proper magnitudes and Z-dependence. Corresponding α D calculated non-relativistically are less reliable on both counts.
Pareto 80/20 law: derivation via random partitioning

The Pareto 80/20 Rule, also known as the Pareto principle or law, states that a small number of causes (20%) is responsible for a large percentage (80%) of the effect. Although widely recognized as a heuristic rule, this proportion has not been theoretically based. The article considers derivation of this 80/20 rule and some other standard quotients from the mean and its interval estimation for the total value defined by the product of two variables in the random partitioning model.
An Eight-Step Kinetics Mechanism for High Temperature Propane Flames

Abstract An accurate eight-step kinetics mechanism for the high temperature oxidation of propane has been developed. This model is based on previous experimental research and has been developed in ignition delay studies and investigations of freely propagating and quenching flames. Results from a detailed kinetics model and available experimental data were used for comparison and verification of the multi-step model. One-dimensional transient calculations were performed at pressures ranging from one to 40 atmospheres, unburned gas/wall temperatures from 400 to 500 K, and propane-air equivalence ratios from 0·7 to 1·3. Shortcomings in the earlier four-step and eight-step models are identified and strategies for improvement of the simplified model are discussed. Based on this work, the original eight-step model is modified to improve representation of the induction region, flame speed, postflame region, wall-quench behavior, and unburned hydrocarbon evolution. Correlations which extend the model to a wider ...
3D computational reconstruction of tissues with hollow spherical morphologies using single-cell gene expression data

Single-cell gene expression analysis has contributed to a better understanding of the transcriptional heterogeneity in a variety of model systems, including those used in research in developmental, cancer and stem cell biology. Nowadays, technological advances facilitate the generation of large gene expression data sets in high-throughput format. Strategies are needed to pertinently visualize this information in a tissue structure-related context, so as to improve data analysis and aid the drawing of meaningful conclusions. Here we describe an approach that uses spatial properties of the tissue source to enable the reconstruction of hollow sphere-shaped tissues and organs from single-cell gene expression data in 3D space. To demonstrate our method, we used cells of the mouse otocyst and the renal vesicle as examples. This protocol presents a straightforward computational expression analysis workflow, and it is implemented on the MATLAB and R statistical computing and graphics software platforms. Hands-on time for typical experiments can be <1 h using a standard desktop PC or Mac.
Haemolymph lipoprotein transport of juvenile hormone.

Abstract Studies utilizing Sephadex chromatography, slab gel electrophoresis, thin-layer chromatography, and bioassay indicate that the yellow high-density lipoprotein (yHDL) found in the haemolymph of saturniid moths is involved in the transport of juvenile hormone. Although all six haemolymph lipoproteins can bind 14C-2-juvenile hormone in vitro, only the yHDL and yellow very highdensity lipoprotein (yVHDL) bind juvenile hormone in vivo. Pupal yHDL binds exogenously applied juvenile hormone even though this developmental stage normally does not have juvenile hormone. When yHDL from a stage (male adult) with a high juvenile titre is bioassayed, the results were positive whereas normal pupal yHDL and adult male haemolymph proteins minus the yHDL were ineffective. Further studies revealed that 14C-2-juvenile hormone is converted to a more polar compound(s) both in haemolymph in vitro and when injected into pharate adults. This material is accumulated by the gut and may be an excretory product. Material less polar than juvenile hormone was detected by thin-layer chromatography. Preliminary isotope dilution experiments suggest that 1 mg yHDL is capable of binding a minimum of 60 μg of juvenile hormone although this large amount is never present in the insect.
The effectiveness of managing social media on hotel performance.

Abstract This paper investigates how managing online reviews affects hotel performance. An international hotel chain provided the hotel performance data and the online review data. A leading social media firm for the hospitality industry collected the online review data, which the hotel company purchased. The results indicate that overall ratings are the most salient predictor of hotel performance, followed by response to negative comments. The better the overall ratings and the higher the response rate to negative comments, the higher the hotel performance. Therefore, online reviews in social media, specifically overall rating and response to negative comments, should be managed as a critical part of hotel marketing.
Ascending Aortic Aneurysms with Associated Aortic Regurgitation

Abstract A safe method for replacement of the entire aortic valve, root, and ascending aorta for aortic insufficiency associated with an ascending aortic aneurysm is supported. This method utilizes a composite synthetic graft and valve with direct annular suture and implantation of the coronary arteries in the graft. The advantages of the technique include a shortened operation and freedom from postoperative hemorrhage, paraprosthetic leakage, and recurrent aneurysm formation.
Mutational Analysis of Bovine Leukemia Virus Rex: Identification of a Dominant-Negative Inhibitor

The Rex proteins of the delta-retroviruses act to facilitate the export of intron-containing viral RNAs. The Rex of bovine leukemia virus (BLV) is poorly characterized. To gain a better understanding of BLV Rex, we generated a reporter assay to measure BLV Rex function and used it to screen a series of point and deletion mutations. Using this approach, we were able to identify the nuclear export signal of BLV Rex. Further, we identified a dominant-negative form of BLV Rex. Protein localization analysis revealed that wild-type BLV Rex had a punctate nuclear localization and was associated with nuclear pores. In contrast, the dominant-negative BLV Rex mutation had a diffuse nuclear localization and no nuclear pore association. Overexpression of the dominant-negative BLV Rex altered the localization of the wild-type protein. This dominant-negative derivative of BLV Rex could be a useful tool to test the concept of intracellular immunization against viral infection in a large animal model.
The Galapagos Spreading Centre: Heat-flow low on the North Flank

Summary The axis of the Galapagos spreading centre has a high but variable heat flow. A distinct local minimum in the heat-flow field exists in a region 4–6 My old on the northern flank of the spreading centre. This minimum is unlikely to have been produced from refraction of heat flux due to either topographic and sediment thickness irregularities or to the transient effect of sediment loading. We suggest that the oceanic crust has an ‘effective’ permeability to fluid flow and that hydrothermal circulation causes much of the heat loss to arise through mass transport. This mechanism also lowers the conductive heat flow from beneath the sediments causing a regional minimum in the observed heat flux. We consider two different models for the control of the ‘effective’ permeability. The first invokes chemical reactions to open and close the cracks which give rise to the ‘effective’ permeability. In the second, no reactions are invoked and the oceanic crust never completely loses its permeability. The latter model implies that in areas of rough topography with outcropping basement highs the regional heat flow cannot be determined solely by conductive measurements.
Chemotherapy in treatment of non-Hodgkin’s lymphoma in pregnancy

Abstract Background: Non-Hodgkin’s lymphoma (NHL) occurs rarely in pregnancy. Even when the mother survives, the pregnancy often is terminated because of fear of the teratogenic effects of chemotherapy. After discussing the uncertain risks with her family, our patient underwent treatment, and a viable fetus was subsequently delivered. Case: A 27-year-old white woman, gravida 1, para 0-0-0-0, presented at 16 weeks of gestation complaining of persistent nonproductive cough and shortness of breath. A chest X-ray revealed a mediastinal mass that was found on magnetic resonance imaging to be 13 cm × 6 cm × 10 cm. A computed tomography–guided biopsy revealed NHL. The patient was counseled regarding response of NHL stage III to chemotherapy and the uncertain effect on the fetus. She was treated at 3-week intervals with eight courses of chemotherapy of cyclophosphamide, doxorubicin, vincristine, prednisone, and allopurinol (CHOP) as is usual at our institution for stage III NHL. Chemotherapy was stopped 3 weeks before planned delivery at 34 weeks of gestation to minimize the risk of delivering a neutropenic newborn. The fetus was delivered vaginally after induction of labor; birth weight was 3,043 g and Apgar score was 9,9,9, without neonatal compromise. Maternal remission occurred after continuation of planned treatment, including completion of her course of chemotherapy and radiation. Conclusion: In selected cases, fetal life can be preserved while the mother is aggressively treated for non-Hodgkin’s lymphoma, and both mother and fetus can survive the disease.
Recent versus Remote: Flashbulb Memory for 9/11 and Self-Selected Events from the Reminiscence Bump

In two related studies, we examined flashbulb memories acquired from different points in the lifespan in younger and older adults. When asked to remember flashbulb memories from their lives, older adults were most likely to recall events from the reminiscence bump (Study 1A). In Study 1B, younger and older adults recalled 9/11 and a personal flashbulb event that occurred between ages 10 and 30. Older adults' memories of a recent event (9/11) were less likely than younger adults' to be classified as flashbulb memories; however, when memories were examined in their entirety, these age-related declines disappeared. Older adults' memories for a remote flashbulb event appeared to be quite similar, if not more detailed than their memories for the recent event, suggesting that remote flashbulb memories are relatively stable over time. Implications of these data for current views of flashbulb memory in late adulthood are discussed.
The role of astrocytes in hepatic encephalopathy.

The Alzheimer type II astrocyte change is the distinctive morphologic alteration in brain of humans and experimental animals succumbing to hepatic encephalopathy (HE). Whether this change is a primary event in the pathogenesis of HE or whether it is secondary to injury of some other component(s) of the CNS has not been clarified. Studies in a rat model of HE have revealed early reactive changes in astrocytes characterized by cytoplasmic hypertrophy. During the later phases, degenerative changes ensue corresponding to the Alzheimer type II change observed by light microscopy. In view of the role of astrocytes in ammonia detoxification and the importance of ammonia in the pathogenesis of HE, we have suggested that the initial astrocytic changes are the morphological correlates of ammonia detoxification. We have speculated that the later degenerative alterations could lead to failure by astrocytes to carry out key functions (e.g., neurotransmitter uptake, ion regulation, and the like) and contribute to the development of the encephalopathy. Recently, the potential involvement of astrocytes in HE has been further investigated, using primary astrocyte cultures. Exposure of cultures to ammonia at clinically relevant concentrations has shown morphologic changes closely resembling those observed in experimental HE in vivo. These deleterious effects can partly be prevented by raising cyclic AMP levels in cells. Other potential toxins (octanoic acid, phenol) have shown pathologic changes as well. Although some alterations were common to all three, they each possessed distinctive pathological effects. A synergistic interaction has also been demonstrated with these toxins. Functional studies of ammonia-treated astrocytes have shown the following: With low doses or short-term exposure, the uptakes of K+, glutamate, and GABA remained unchanged or slightly increased, whereas with higher doses or longer treatment, those activities diminished. A fall in ATP values occurred with prolonged ammonia treatment. Preliminary findings have shown no significant derangements in the beta-adrenergic receptor, except for a slight decrease in receptor affinity. However, cyclic AMP production was diminished following stimulation with isoproterenol. A slight rise in the number of benzodiazepine receptors was found. These studies indicate that profound changes occur in astrocytes following exposure to ammonia and other putative toxins. It is proposed that toxins and factors involved in the precipitation of HE do so by affecting astroglial properties. Derangements in such properties may lead to glial dysfunction (primary gliopathy), resulting in an encephalopathic state.
Do the histologic features and results of breast cancer biomarker studies differ between core biopsy and surgical excision specimens

Summary Core biopsies are commonly used in the diagnosis of breast cancer and often are the only sample for providing prognostic and predictive markers prior to neoadjuvant chemotherapy. We retrospectively studied 87 patients with breast cancer to compare the concordance rates for tumor type, grade, estrogen receptor/progesterone receptor (ER/PR), p53 status and Her2/neu by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) between core and excisional biopsy specimens. The histologic type of cancer had a 100% concordance rate between core and excisional biopsy specimens. The concordance rate of modified Bloom–Richardson score between core and excisional biopsy specimens was 77%, ER was 95%, PR was 89%, and p53 was 86%. The concordance rate for Her2/neu by IHC was 96% and that for FISH was 100% between the core and excisional biopsy specimens. Although breast cancer may have heterogeneous histological and immunohistochemical findings, our study shows that relatively high concordance rates can be obtained when comparing core and excisional biopsy specimens.
Illustrating Chemical Concepts with Coin Flipping

Three classroom demonstrations, which involve the participation of students flipping coins, are described. The half-life of a first-order chemical reaction is illustrated by standing students sitting down when they flip a “tails.” Dynamic chemical equilibrium is illustrated by students standing or sitting depending on the outcome of coin-flips. In a third demonstration, the motion of gas molecules from one bulb to another is governed by the flip of a coin, showing the improbability of all the molecules gathering in just one bulb.
Dehydration and basal insulin requirement.

SummaryDepancreatized dogs maintained on a standard regime were dehydrated by producing glycosuria along with restricted water intake. It was found that the basal insulin requirement of the animals in this state was increased above that which they had normally without dehydration, but with other conditions the same.If the dogs be given enough water so that no dehydration results from the glycosuria no increase in the basal insulin requirement results.
Spatial categorization and time perception: Why does it take less time to get home?

Abstract This paper identifies a new bias in consumers' time perceptions — consumers perceive a journey from a destination to home to be faster than a trip from home to the same destination. In three experiments we demonstrate that this effect occurs both for short trips and for long trips to and from home. We also show that this effect occurs for other familiar locations in addition to home. We discuss several possible causes for this effect and offer preliminary support for one possible reason that involves differences in how consumers spatially encode “home” vs. a destination. Since home is extremely familiar it enjoys a rich mental representation, and therefore, consumers may encode it as a relatively larger geographical area than the less familiar destination. We offer preliminary evidence that this can lead to a directional asymmetry in their feelings of trip progress.
The Disappearance of Skid Row: Some Ecological Evidence

Census tract data are employed to examine demographic changes between 1950 and 1970 for skid row neighborhoods in 41 American cities. While the directions of trends in skid row population composition parallel those of the central city, such changes have not been of sufficient magnitude to alter skid row-central city differences which were present in 1950: skid rows remain disproportionately comprised of single, older, low-status males. However, major losses in population threaten the existence of many traditional skid row districts. The declining number of skid row residents appears to be empirically related to demographic characteristics of both the skid row neighborhood and the central city. These results are discussed in terms of ecological theories of urban growth, with attention given to the evolving functional role played by skid row in the larger urban context.
Amyotrophic Lateral Sclerosis and Spinocerebellar Ataxia Type 2 in a Family With Full CAG Repeat Expansions of ATXN2

Importance A family with coexistence of spinocerebellar ataxia type 2 and amyotrophic lateral sclerosis (ALS) is described. Observations Intermediate or full CAG repeat expansions of ATXN2 are associated with ALS. However, no coexistence of spinocerebellar ataxia type 2 and ALS in a family has been reported in the literature. We describe a 47-year-old woman with an 11-year history of ataxia and her paternal uncle with ALS who were evaluated at Columbia University Medical Center since July 2006. Both our patient with ataxia and her uncle with ALS have full pathological CAG repeat expansions of ATXN2. Conclusions and Relevance The diverse clinical phenotypes of ATXN2 CAG expansions and their coexistence in a single family are highlighted. A clinician should consider the diagnosis of spinocerebellar ataxia type 2 when encountering a patient with ataxia and a family history of ALS.
Characterization of density-dependent regulation of the tyrosinase gene promoter: role of protein kinase C.

Abstract The rate-limiting step in melanogenesis is catalyzed by tyrosinase, a multifunctional enzyme encoded by thealbinolocus. We have previously reported that depletion of protein kinase C by long-term treatment of B16 mouse melanoma cells with phorbol dibutyrate (PDBu) prevented cell density-dependent melanogenesis. This was accompanied by a lack of induction of tyrosinase protein and mRNA. We report here the effect of PDBu on the functional activity of the mouse tyrosinase promoter by reporter gene assay and its effect on the binding of nuclear proteins from B16 cells to the “M-box” region of the mouse tyrosinase promoter. Short-term PDBu treatment of B16 cells transfected with a mouse tyrosinase promoter–luciferase construct resulted in increased reporter gene activity, while long-term PDBu treatment inhibited reporter gene activity. Using an oligonucleotide containing the M-box and its flanking residues in electrophoretic mobility shift assays, we found a density-dependent change in the pattern of DNA–protein complexes. One complex was found to be negatively regulated by long-term PDBu treatment. Competition experiments with various mutated oligonucleotides demonstrated that both the M-box and flanking residues are important for nuclear protein binding. The complex whose formation was inhibited by long-term PDBu treatment was shown to contain the basic helix-loop-helix leucine zipper proteinmicrophthalmia-associatedtranscriptionfactor (MITF). These results suggest that chronic PDBu treatment might inhibit tyrosinase expression (and subsequent melanogenesis) by affecting the amount or function of MITF.
Trends in the use of pre-operative radiation for adenocarcinoma of the pancreas in the United States

Background The benefit and timing of radiation therapy (RT) for patients undergoing a resection for pancreatic adenocarcinoma remains unclear. This study identifies trends in the use of radiation over a 10-year period and factors associated with the use of pre-operative radiation, in particular.
Primary Pericardial Mesothelioma in a 19-Year-Old Presenting as Pericarditis

Primary pericardial mesothelioma is a rare clinical entity. The association between asbestos and pericardial mesothelioma has not been well established, partly due to the small number of reported patients. Treatment options are limited for this very aggressive cancer. Surgical resection in the form of pericardiectomy can be curative, but owing to the frequently late presentation, surgical intervention is usually palliative. Chemotherapy and radiotherapy have overall poor results. We present the case of a 19-year-old man who initially had symptoms of pericarditis. He died 1 year after initial presentation.
Leptin Selectively Augments Thymopoiesis in Leptin Deficiency and Lipopolysaccharide-Induced Thymic Atrophy

The thymus is a lymphoid organ that selects T cells for release to the peripheral immune system. Unfortunately, thymopoiesis is highly susceptible to damage by physiologic stressors and can contribute to immune deficiencies that occur in a variety of clinical settings. No treatment is currently available to protect the thymus from stress-induced involution. Leptin-deficient (ob/ob) mice have severe thymic atrophy and this finding suggests that this hormone is required for normal thymopoiesis. In this study, the ability of leptin to promote thymopoiesis in wild-type C57BL/6 and BALB/c mice, as well as in leptin-deficient (ob/ob) and endotoxin-stressed (Escherichia coli LPS) mice, was determined. Leptin administration induced weight loss and stimulated thymopoiesis in ob/ob mice, but did not stimulate thymopoiesis in wild-type C57BL/6 nor BALB/c mice. In endotoxin-stressed mice, however, leptin prevented LPS-induced thymus weight loss and stimulated TCRα gene rearrangement. Coadministration of leptin with LPS blunted endotoxin-induced systemic corticosterone response and production of proinflammatory cytokines. Thus, leptin has a selective thymostimulatory role in settings of leptin deficiency and endotoxin administration, and may be useful for protecting the thymus from damage and augmenting T cell reconstitution in these clinical states.