cssi/SciSciGPT-SciSciNet huggingface dataset:
Transmissible vaccines whose dissemination rates vary through time, with applications to wildlife

Transmission is a potential property of live viral vaccines that remains largely unexploited but may lie within the realm of many engineering designs. While likely unacceptable for vaccines of humans, transmission may be highly desirable for vaccines of wildlife, both to protect natural populations and also to limit zoonotic transmissions into humans. Defying intuition, transmission alone does not guarantee that a vaccine will perform well: the benefit of transmission over no transmission depends on and increases with the basic reproductive number of the vaccine, R0. The R0 of an infectious agent in a homogeneous population is typically considered to be a fixed number, but some evidence suggests that dissemination of transmissible vaccines may change through time. One obvious possibility is that transmission will be greater from hosts directly vaccinated than from hosts who acquire the vaccine passively, but other types of change might also accrue. Whenever transmission changes over time, the R0 estimated from directly vaccinated hosts will not reflect the vaccine’s long term impact. As there is no theory on the consequences of changing transmission rates for a vaccine, we derive conditions for a transmissible vaccine with varying transmission rates to protect a population from pathogen invasion. Being the first in the transmission chain, the R0 from directly vaccinated hosts has a larger effect than those from later steps in the chain. This mathematical property reveals that a transmissible vaccine with low long term transmission may nonetheless realize a big impact if early transmission is high. Furthermore, there may be ways to artificially elevate early transmission, thereby achieving high herd immunity from transmission while ensuring that the vaccine will ultimately die out.
Impaired αVβ8 and TGFβ signaling lead to microglial dysmaturation and neuromotor dysfunction

Microglia play a pivotal role in the coordination of brain development and have emerged as a critical determinant in the progression of neurodegenerative diseases; however, the role of microglia in the onset and progression of neurodevelopmental disorders is less clear. Here we show that conditional deletion of αVβ8 from the central nervous system (Itgb8ΔCNS mice) blocks microglia in their normal stepwise development from immature precursors to mature microglia. These "dysmature" microglia appear to result from reduced TGFβ signaling during a critical perinatal window, are distinct from microglia with induced reduction in TGFβ signaling during adulthood, and directly cause a unique neurodevelopmental syndrome characterized by oligodendrocyte maturational arrest, interneuron loss, and spastic neuromotor dysfunction. Consistent with this, early (but not late) microglia depletion completely reverses this phenotype. Together, these data identify novel roles for αVβ8 and TGFβ signaling in coordinating microgliogenesis with brain development and implicate abnormally programmed microglia or their products in human neurodevelopmental disorders that share this neuropathology.
A latent profile analysis of coping responses to individuals' most traumatic event: associations with adaptive and maladaptive mental health outcomes.

ABSTRACTBackground & Objectives: This study explores how empirically-derived coping response patterns influence mental health.Design: Emerging adults, currently enrolled in college and aged 18–24 (...
TCT-464 The Volume Outcomes for Percutaneous Mitral Valve Repair (MitraClip) Procedure in a U.S. Registry

MitraClip procedure has been validated as an effective treatment for severe symptomatic mitral valve regurgitation in patients deemed at high surgical risk. The relationship between the hospital volume and procedural outcomes has not been described. Study population was extracted from the 2016
Utility of the cerebroplacental ratio (CPR) in marijuana exposed growth restricted fetuses.

Fetal growth restriction (FGR) is associated with an increased risk of adverse perinatal outcomes. The cerebroplacental ratio (CPR) represents the interaction of alterations in blood flow to the fe...
Adaptive Active – Embedding Inclusion into Activewear

Adaptive Active reflects the need for activewear that is inclusive of people living with disabilities and cogitates that people with disabilities are physically active individuals. The design consists of three separate activewear garments including a vest, shell, and jumper, each having features to enhance easier donning and doffing. For example, the lower half of the vest is removable for people who are in a seated position. The shoulder seam of the jumper unsnaps to create a larger armhole, and the shell secures with magnets at each shoulder. The designer used body scans of a fit model in both standing and seated positions to develop half-scale dress forms. Patterns were draped on the half-scale forms and digitized into Adobe Illustrator where the laser cut embellishments were added. The final patterns were increased to full-scale in Illustrator, laser cut, and constructed using industrial sewing techniques. The materials used in this design were ripstop nylon and polyester/spandex scuba knit.
Approaches to Risk Management and Operational Guidance for Municipal Water Supplies

The proper initiation of water use restrictions for municipal water systems should depend upon the risk of system shortfall, the economic loss associated with those shortfalls, and the range of management options available. Often these considerations are overshadowed by more subjective considerations that can not be easily quantified. This paper presents the results of a risk methodology designed to integrate quantitative factors into optimal policies through the use of an operational database. This methodology evaluates the range of economic risk associated with each management option. A discussion of a response curve approach also is presented with an application to the Seattle, Washington water supply system. These issues are pursued further in additional papers found in these proceedings by the author in which the more subjective aspects of the problems are addressed.
7T MPFLAIR versus MP2RAGE for Quantifying Lesion Volume in Multiple Sclerosis

BACKGROUND AND PURPOSE Use of fluid-attenuated inversion recovery (FLAIR) scans to quantify multiple sclerosis (MS) lesion volume on 7 Tesla (7T) magnetic resonance imaging (MRI) has many downsides, including poor image homogeneity. There are little data about the relative benefit of alternative modalities. The purpose of this paper is to investigate if magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) is a viable alternative to FLAIR for robust lesion volume measurement and disability correlations. METHODS Forty-seven participants with MS underwent annual brain 7T MRIs. Magnetization-prepared FLAIR (MPFLAIR) and MP2RAGE (both at .7 mm3 isotropic resolution) sequences from a total of 80 MRI scans from 47 subjects were reviewed. White matter lesion (WML) masks were manually constructed from MPFLAIR and T1 maps (from MP2RAGE). Lesion volumes (normalized to intracranial volume) were compared to clinical characteristics and disability scales scores by Pearson or Spearman correlation, as appropriate. Relative correlation strength was compared by Fisher r- to z-transformation. RESULTS Normalized lesion volume was greater in MPFLAIR masks (median .005 [range, .001-.030]) than from T1 maps (median .003 [range, .000-.015]). However, lesion volumes between MPFLAIR and T1 maps were highly correlated (rho = .87, P < .001). WML masks from both modalities correlated with most disability measures with no significant difference in the strength of correlation. CONCLUSIONS 7T MPFLAIR and MP2RAGE T1 map-based WML volumes are highly intercorrelated and both correlate with disability. Thus, MP2RAGE may be a viable alternative to FLAIR-based methods for WML measurement on 7T MRI in MS research.
Don’t Give Away the Razor (Usually): A Note on Two-Part Tariffs

The so-called “razor-and-blades” pricing strategy involves setting a low price for a durable basic product (razors) and a high price for a complementary consumable (blades). Oi (1971) showed that if consumers’ demand curves differ and do not cross, a monopolist should always price blades above cost. This note studies the optimal razor price, assuming constant unit costs and linear demands. With a uniform distribution of parallel demand curves it is never optimal to sell the razor below cost, while with two types of consumers and non-crossing demands it is optimal to do so for some parameter values.
CoopStore: optimizing precomputed summaries for aggregation

An emerging class of data systems partition their data and precompute approximate summaries (i.e., sketches and samples) for each segment to reduce query costs. They can then aggregate and combine the segment summaries to estimate results without scanning the raw data. However, given limited storage space each summary introduces approximation errors that affect query accuracy. For instance, systems that use existing mergeable summaries cannot reduce query error below the error of an individual precomputed summary. We introduce CoopStore, a query system that optimizes item frequency and quantile summaries for accuracy when aggregating over multiple segments. Compared to conventional mergeable summaries, CoopStore leverages additional memory available for summary construction and aggregation to derive a more precise combined result. This reduces error by up to 25 x over interval aggregations and 4.5 x over data cube aggregations on industrial datasets compared to standard summarization methods, with provable worst-case error guarantees.
Seeing With My Ears.

Abstract Therapeutic presence is one of the fundamental skills that palliative care providers have to offer. The COVID-19 pandemic has created many barriers to connection that impact the way providers practice. This narrative piece about a remote cross-country palliative care encounter offers reflections on creating therapeutic presence amidst the current pandemic.
α-Synuclein modulates tau spreading in mouse brains

α-Synuclein (α-syn) and tau aggregates are the neuropathological hallmarks of Parkinson's disease (PD) and Alzheimer's disease (AD), respectively, although both pathologies co-occur in patients with these diseases, suggesting possible crosstalk between them. To elucidate the interactions of pathological α-syn and tau, we sought to model these interactions. We show that increased accumulation of tau aggregates occur following simultaneous introduction of α-syn mousepreformed fibrils (mpffs) and AD lysate-derived tau seeds (AD-tau) both in vitro and in vivo. Interestingly, the absence of endogenous mouse α-syn in mice reduces the accumulation and spreading of tau, while the absence of tau did not affect the seeding or spreading capacity of α-syn. These in vivo results are consistent with our in vitro data wherein the presence of tau has no synergistic effects on α-syn. Our results point to the important role of α-syn as a modulator of tau pathology burden and spreading in the brains of AD, PDD, and DLB patients.
Heating and Convective Cooling of Two-Dimensional Solids Using Diffusion and Cattaneo–Vernotte Models

Thermal diffusion and wave phenomena in a two-dimensional solid subjected to convective cooling and an internal exponential heat source are investigated. Both diffusion and Cattaneo–Vernotte (C–V) ...
Improved Potting of Litz Wires for High Power Density Electric Motor

Specific details including selections of process materials, tooling/fixture setups, and a step-by-step procedure for scaling-up demonstrations of the newly developed potting process, namely vacuum-assisted axial injection potting (VaAIP) have been fully developed for the stator winding of high power density electric motors for the future electrified aircrafts. Various essential pre-trial subtasks identified for the full-scale demonstrations were carried out. To date, optimization of cure condition and thermal stability of the coating epoxy and determination of optimum application conditions and thermal stability of the high temperature encapsulant wax were completed successfully and other subtasks were under way. The efforts to enhance thermal conductivity of the selected potting compound by adding conductive nano fillers such as boron nitride nanosheets (BNNS) have also been advanced. Initially, selection of the best mixing method and procedures was attempted via extensive and systematic experimental design.
Soil Survey Laboratory Methods for Characterizing Physical and Chemical Properties and Mineralogy of Soils

This paper outlines the analytical methods currently used by the Soil Survey Laboratory of the National Soil Survey Center and other laboratories of the National Cooperative Soil Survey. Most the methods were developed and tested over a period of years. Modifications of original methods have been made to facilitate automation and improve reliability. The chemical determination include organic carbon, total nitrogen, extractable iron, aluminum, manganese, calcium, magnesium, sodium, potassium, and acidity, water-soluble cations and anions, carbonates, gypsum, cation exchange capacity, and various pH measurements. The mineralogical analyses include optical analysis of a sand or a silt fraction and X-ray diffraction and differential scanning calorimetric analysis of the clay fraction. The petrographic microscope is used to identify and count grains mounted on glass slides. X-ray diffraction analysis is made on clay films on glass slides with and without heat treatments and saturation with potassium, magnesium, and magnesium and glycerol. Differential scanning calorimetric analyses are made on samples equilibrated at 50% relative humidity.
Comparison of Measured and Calculated Reaction Rates from D2O-Moderated 252cf Neutrons

Activation detectors and an N.B.S. fission chamber have been used to measure reaction rates at several distances between 25 cm and 150 cm from the D2O-moderated 252Cf source at the University of Arkansas. This source is a duplicate of the 15 cm radius D2O-moderated 252cf source used at the U.S. National Bureau of Standards. The reactions measured were 197Au(n,γ), 115In(n,n’), 32S(n,p), 58Ni(n,p), 235U(n,f) and 237Np(n,f). Corrections for room-scatter, for air-scattering and for non-l/r2 effects near the source were applied to obtain the expected free-field reaction rates. Cross-sections from the ENDF/B V file and the D2O-moderated source spectrum from the Monte Carlo calculation of H. Ing and W. G. Cross were used to calculate reaction rates which are compared with the measured results.
How much longer can we afford the AIDS virus monopoly

Until 1984 AIDS science was open. Initially the new epidemic of pneumonias and Kaposi’s sarcomas, since called AIDS, was considered a collection of non-infectious ‘lifestyle’ diseases. But the Centers for Disease Control in Atlanta published that the pneumonias and Kaposi’s sarcomas of male homosexuals, who were addicted to recreational drugs, were caused by a common infectious agent because patients had been ‘linked’ by sexual contacts. On the basis of the CDC’s sexual linkage study, the Secretary of Health and Human Services announced in 1984 the hypothesis that the retrovirus HIV, is the cause of AIDS. The HIV-AIDS hypothesis currently holds a monopoly on all AIDS research and treatment. However, the HIV hypothesis is scientifically unproven. It has failed each of 15 testable predictions, as for example that AIDS would explode via sexual transmission of HIV into the general population. Moreover HIV meets all classical criteria of a harmless passenger virus: unpredictable intervals between infection and any subsequent disease, and unpredictable presence and activity of the virus during a disease. Since HIV is rare in the US, it is a marker of real AIDS risks, frequent injection of intravenous drugs, thousands of drug-mediated sexual contacts, and transfusions. Indeed, AIDS does not meet even one of the classical criteria of an infectious disease, as for example equal distribution between the sexes, disease within days or weeks after infection, and exponential spread of the disease in an un-immunized population (Farr’s law).
Analysis of the cell cycle in zebrafish embryos.

Publisher Summary This chapter discusses the analysis of the cell cycle in Zebrafish Embroys. The advantages of the zebrafish system that make it a powerful organism to study vertebrate development include external fertilization of oocytes, transparent embryos, and rapid embryonic development. These features also provide the opportunity to study early cell divisions and tissue-specific cellular proliferation. This chapter provides protocols for assays that characterize various phases of cell division in zebrafish embryos. It discusses the design of screens for mutations aVecting embryonic cell proliferation and a method to detect the novel compounds affecting the zebrafish cell cycle. Assays discussed in this chapter include: DNA content analysis by flow cytometry, whole-mount embryonic antibody staining, mitotic spindle analysis, 5-bromo-2-deoxyuridine (BrdU) incorporation, cell death analysis, and in situ hybridization with cell cycle regulatory genes. Finally, this chapter concludes with the genetic tractability of the zebrafish system that makes it an excellent organism, in which to pursue forward genetic screens for mutations or chemical screens for novel compounds that alter cell division using one or more of these cell cycle assays.
Shock Options: The Stock Options Backdating Scandal of 2006 and the SEC's Response

This paper summarizes the recent stock options backdating scandal from the perspective of the Securities and Exchange Commission. The paper begins with a brief history of the stock options expensing debate. The paper continues with a discussion of the academic research that propelled the phenomenon of options backdating into the media and regulatory spotlight. The paper then examines three case studies of companies and executives charged by the Commission. The paper concludes with a brief analysis of the Commission's recent policy regarding company fines.
Pacific Worlds: Asia, America, and the age of the galleons

On November 3, 1579 a ship dropped anchor at Ternate, the Spice Islands, guided by fishermen in canoes off the island of Siau, north of Celebes. Onboard, its captain was one of the best-known pirates of his generation, and he had just sailed across the ocean from the coast of South America. The Chinese Lim Ah Hong had just a few years before vanished from historical records. Here was a pirate from another line, that of the Anglo-Saxons: Francis Drake. At Ternate, Drake met with Sultan Baab, himself recently victorious at having ousted the Portuguese, and they regaled each other with tales and traded for spices. Drake avoided the nearby island of Tidore, where a Spanish position would easily have recognized him. Drake was emblematic of a new presence in the Pacific, coming not across the Indian Ocean, but across the Pacific by the Straits of Magellan. This presence was Dutch and British, arriving for exploration, but more, for the specific purpose of preying upon the empire of the powerful Spanish Crown by capturing its treasure ships, the fabulous Spanish galleons.
Advantages of a leveled commitment contracting protocol

In automated negotiation systems consisting of self-interested agents, contracts have traditionally been binding. Such contracts do not allow agents to efficiently accommodate future events. Game theory has proposed contingency contracts to solve this problem. Among computational agents, contingency contracts are often impractical due to large numbers of interdependent and unanticipated future events to be conditioned on, and because some events are not mutually observable. This paper proposes a leveled commitment contracting protocol that allows self-interested agents to efficiently accommodate future events by having the possibility of unilaterally decommitting from a contract based on local reasoning. A decommitment penalty is assigned to both agents in a contract: to be freed from the contract, an agent only pays this penalty to the other party. It is shown through formal analysis of several contracting settings that this leveled commitment feature in a contracting protocol increases Pareto efficiency of deals and can make contracts individually rational when no full commitment contract can. This advantage holds even if the agents decommit manipulatively.
Should There Be One Set of Passthrough Rules for All Non-Publicly Traded Businesses? (Option 2 of the Ways and Means Committee Draft to Reform the Taxation of Small Businesses and Passthrough Entities)

This article argues that Option 2 of the March 2013 Ways and Means Committee discussion draft for the reform of the taxation of passthrough entities, which would replace the current S corporation and partnership rules with a single set of rules for all non-publicly traded passthroughs, is much better than simply making changes to specific S corporation and partnership rules. The S corpration rules were enacted for reasons nolonger relevant, and it makes no sense today to distinguish for tax purposes between entities that are and that are not incorpoated. Optioin 2 is far simpler and more straight-forward than the alternatives, and it would also focus on the need to reform payroll taxes.
Tissue Culture of Maize

Callus of 12 strains of maize (Zea mays L.) was grown on a basal medium and on media supplemented singly with 0.3, 1.0 or 3.0 mM of either the glutamate, aspartate, or aromatic families of amino acids. Groth rate on basal medium difrered significantly among strains with Black Mexican Sweet corn growing most rapidly. Although there were three cases of simulation of callus growth at the 0.3 mM level and one case at the 1.0 mM level, generally the addition of amino acid families had either no effect or were inhibitory to growth rate. The sensitivity of inhibition varied among the strains tested at the 3.0 mM level except for the strain Ibadan B. Strains of the sweet, flint, pop and dent types of maize were all represented among the more fapidly growing strains and among those significantly inhibited by inclusion of amino acids in the cultural media. It remains to be determined as to whether the differences in growth response of the callus from the different strains is strain specific since, in all cases but one, callus was obtained from a single seedling of each strain.
Statistical and economic models for analysis and optimal design of laboratory screening policies for cervical cancer

This paper develops several statistical and economic models in order to analyze the accuracy and total cost of laboratory procedures commonly used in examining Pap smears for early indications of cervical cancer. In particular, the expected values, variances, and probability distributions are derived for the overall system sensitivity, overall system specificity, workload, and total system cost of several possible laboratory screening policies. These models are useful for analytically comparing possible alternative screening processes and for identifying the optimal minimum societal cost policy. Additionally, these models are used to show that the overall screening process never can have higher sensitivity nor lower specificity than the pathologist, that a rescreening rate of either 0% or 100% always will be economically optimal, and that total costs are highly variable period to period. While a primary objective of the present paper is to develop analytic and research tools, preliminary applied results suggest that significant improvements in sensitivity and reductions in total societal costs are possible by changing the policy currently required by the congressional Clinical Laboratory Improvement Amendments Act of 1988, typically with one to three repeated cytotechnologist screenings of presumed negative smears. Sensitivity analysis indicates these results are very dependent on cost and other inputs, and several directions for continued research therefore are described. Use of these models at the more micro laboratory and insurer levels, incorporation of automated rescreening devices, and extensions to mammography and other laboratory tests also are briefly discussed.
Mutations in the Poliovirus 3CD Proteinase S1-Specificity Pocket Affect Substrate Recognition and RNA Binding

Sequence and structure comparisons with homologous trypsin-like serine proteases have predicted the S1-specificity pocket in picornavirus 3C proteinases. In this study, we examine the putative roles of such residues in poliovirus 3C substrate recognition. Single amino acid substitutions at 3C residues Thr-142, His-161, Gly-163, Gly-164, and Ala-172 were introduced into near full-length poliovirus cDNAs, and protein processing was examined in the context of authentic 3Cciscleavage activity. Our data are consistent with residues Thr-142, His-161, Gly-163, and Gly-164 acting as important determinants of 3C substrate specificity and support published models of 3C protein structure. Anin vivoanalysis of mutant viruses containing individual amino acid substitutions at 3C residues Thr-142 and Ala-172 suggests that such residues are important determinants for viral RNA replication. In addition, bacterially expressed, recombinant 3CD polypeptides containing amino acid substitutions at Thr-142 and Ala-172 show altered RNA binding properties in mobility shift assays that use a synthetic RNA corresponding to the poliovirus 5′-terminal sequences.
Quantification and modeling of macropore drainage

Abstract A series of experiments on undisturbed soil columns, followed by interpretation using simulation modeling, were conducted to estimate the influence of soil structure upon macroporosity and water flow. Four large soil columns taken from Niagara silt loam and Rhinebeck silty clay loam profiles were placed on a grid sampler to obtain 25 subsample outflow measurements per column. Columns were saturated from the bottom and saturated hydraulic conductivity was measured under shallow ponding. Columns were then gravity drained while outflow was collected. Saturated hydraulic conductivity and drainage volume were lognormally distributed over the column bottom area. Drainage volumes were not significantly different among columns or soils, at the 5% level. Analysis of the drainage rates of the columns indicated that soil texture influenced macropore geometry by controlling soil structure and plant rooting. Geometric scaling factors from the distribution of saturated hydraulic conductivity, applied to conductivity and potential in simulations of column drainage, did not reproduce the observed distribution of drainage volume. When additional normally-distributed coefficients were applied to porosity, the simulated drainage distributions were not significantly different from observed drainage distributions, at the 5% level.
In defense of the negative affect escape model of heat and aggression.

This article counters Anderson's interpretation of data allegedly inconsistent with the curvilinear negative affect escape model of temperature and aggression. Anderson suggests that archival studies support a rectilinear rather than curvilinear model as temperature increases from comfortable to hot and that inconsistencies surrounding curvilinearity lab studies should be resolved in favor of linearity. To the contrary, this article asserts that archival region and time period studies are inconsistent themselves, that most of them are inadequate for testing curvilinearity, and that some of them are consistent with curvilinearity
Effects of androgen on scent marking and aggressive behavior of neonatally bulbectomized female Mongolian gerbils (Meriones unguiculatus).

Abstract Female gerbils were bilaterally bulbectomized, unilaterally bulbectomized or sham-operated at 2 days of age (Birth day = 0). As adults, the occurrence of scent marking and aggressive behavior was measured prior to and following administration of either testosterone propionate (TP) or oil. TP-treated sham operates showed increased scent marking; bilaterally bulbectomized and unilaterally bulbectomized females treated with TP did not. The display of aggressiveness increased for all females following TP. Neonatally bulbectomized animals treated with TP, however, were the most aggressive. Although androgen augments these species-typical response patterns, it seems dependent upon the integrity of the olfactory bulbs.
Information Literacy Follow-Through: Enhancing Preservice Teachers’ Information Evaluation Skills Through Formative Assessment

An investigation into preservice teachers’ information evaluation skills at a large university suggests that formative assessment can improve student achievement. Preservice teachers were asked to apply information evaluation skills in the areas of currency, relevancy, authority, accuracy, and purpose. The study used quantitative methods to assess preservice teachers’ evaluation skills as demonstrated within the context of a final project, or summative assessment, in an elementary education course. The authors compared the preservice teachers’ and researchers’ evaluations to analyze final projects from two semesters. When asked to evaluate the sources cited in a final project for an education methods course, preservice teachers who received formative feedback from librarians improved in most information evaluation areas. Formative assessment is explored as a tool for improving information literacy instruction.
The Effectiveness of a Solution-Focused Approach for Problem Behaviors Among Nursing Home Residents

Abstract A clinical research project tested the efficacy of a Solution-Focused Approach for addressing problem behaviors of nursing home residents with dementia. A total of 84 family members and nurses aides participated in a controlled study of 21 residents who were aggressive and/or wandered. A repeated measures analysis of variance indicated: (1) family members perceived behaviors as less problematic than did nurses aides; and (2) family members and nurses aides perceived diminished problems in behaviors over time. Based on these findings, suggestions are offered for both practice and future research.
DNA methylation changes in normal liver tissues and hepatocellular carcinoma with different viral infection

Hepatocellular carcinoma (HCC) is known to be associated with both HBV and HCV. While epigenetic changes have been previously reported to be associated with hepatocellular carcinoma (HCC), whether the epigenetic profile of HBC associated HCC differs from that of HCV-associated HCC is unclear. We analyzed DNA methylation of ten genes (APC, CCND2, CDKN2A, GSTP1, HOXA9, RARB, RASSF1, RUNX, SFRP1, and TWIST1) using MethyLight assays on 65 archived liver tissue blocks. Three genes (APC, CCND2, and GSTP1) were frequently methylated in normal liver tissues. Five genes (APC, CDKN2A, HOXA9, RASSF1, and RUNX) were significantly more frequently methylated in malignant liver tissues than normal liver tissues. Among HCC cases, HOXA9, RASSF1 and SFRP1 were methylated more frequently in HBV-positive HCC cases, while CDKN2A were significantly more frequently methylated in HCV-positive HCC cases. Our data support the hypothesis that HCC resulting from different viral etiologies is associated with different epigenetic changes.
Oxygen atom detection using third harmonic generation.

Atomic oxygen has been detected using the four-wave mixing technique of third harmonic generation (THG). Ground state O(3PJ) atoms, generated using a microwave discharge, were monitored by focusing a 391-nm dye laser beam into the post-discharge region and observing radiation at 130 nm, near resonant with the 3s S31∘→2p4 P3J transition, produced along the laser propagation direction. The observed concentration dependent frequency shifts of the laser excitation spectrum verified the assignment of THG. Oxygen atoms were also detected in the same manner following photodissociation of NO2. An important point for diagnostic purposes is that both the VUV intensity and peak frequency shift are dependent on O atom concentration. The relationship between these variables was explored by employing chemical titrations to establish absolute concentration. The demonstrated sensitivity is 5 × 1013 cm−3, but this could be significantly improved. Implications for three-photon resonant multiphoton ionization detection as well as in situ monitoring of atomic oxygen metastable states (1D2 and 1S0) are discussed. Third harmonic generation provides state selective and low aperture detection with sensitivity comparable to other optical methods and shows promise as a general detection technique.
Modeling of Mass Transfer Controlled Adsorption Rate Based on the Langmuir Adsorption Isotherm

Adsorption techniques are extensively used in bulk separations, purifications, and physiochemical parameter determinations. Generally, the adsorption models are described for equilibrium conditions. This study investigates the development of a mathematical model which describes the rate of adsorption under the conditions when the dynamic mass transfer is the controlling step. The underlying assumption is that the equilibrium isotherms can be used to describe the adsorption phenomena. A mathematical model for the external mass transfer controlled adsorption rate based on the Langmuir adsorption isotherm was developed and validated using data reported in literature using different adsorbents and adsorbates. In addition, using Freundlich adsorption isotherm, mathematical models for zero, one-half, and first-order were obtained. The various relevant parameters, namely the adsorption capacity, the adsorption energy, and the mass transfer coefficients were evaluated and the extension of the model to energetical...
Semiautomatic registration of volumetric ultrasound scans

We demonstrate the ability to register easily and accurately volumetric ultrasound scans without significant data preprocessing or user intervention. Two volumetric ultrasound breast scan data sets were acquired from two different patients with breast cancer. Volumetric scan data were acquired by manually sweeping a linear array transducer mounted on a linear slider with a position encoder. The volumetric data set pairs consisted of color flow and/or power mode Doppler data sets acquired serially on the same patients. A previously described semiautomatic registration method based on maximizing mutual information was used to determine the transform between data sets. The results suggest that, even for the deformable breast, three-dimensional full affine transforms can be sufficient to obtain clinically useful registrations; warping may be necessary for increased registration accuracy. In conclusion, mutual information-based automatic registration as implemented on modern workstations is capable of yielding clinically useful registrations in times <35 min.
Cardiac PACS — A digital system for real time cardiac image visualization and management

A for real time synchronous digital recording, visualization and archiving of still and full motion cardiac images and audio data from ultrasound imaging systems has been developed. The echocardiographic video signals in RGB or PAL/NTSC format are digitized at a rate of 30 frames per second and compressed in real time down to 250 KB/second bit stream. The video images are recorded synchronously with electrocardiogram resulting in a sequence of time segments corresponding to the duration of heart beats. A real time synchronous serial comparison of recorded cardiac image data with live images is also provided. The visualization functions provide an instant access to selected image sequences, cine' loops and still images displayed on the screen of an ultrasound machine in a user desired format such as split, quad or hex screen display.
Vascular biomechanical properties in mice with smooth muscle specific deletion of Ndst1

Heparan sulfate proteoglycans act as co-receptors for many chemokines and growth factors. The sulfation pattern of the heparan sulfate chains is a critical regulatory step affecting the binding of chemokines and growth factors. N-deacetylase-N-sulfotransferase1 (Ndst1) is one of the first enzymes to catalyze sulfation. Previously published work has shown that HSPGs alter tangent moduli and stiffness of tissues and cells. We hypothesized that loss of Ndst1 in smooth muscle would lead to significant changes in heparan sulfate modification and the elastic properties of arteries. In line with this hypothesis, the axial tangent modulus was significantly decreased in aorta from mice lacking Ndst1 in smooth muscle (SM22αcre+Ndst1−/−, p < 0.05, n = 5). The decrease in axial tangent modulus was associated with a significant switch in myosin and actin types and isoforms expressed in aorta and isolated aortic vascular smooth muscle cells. In contrast, no changes were found in the compliance of smaller thoracodorsal arteries of SM22αcre+Ndst1−/− mice. In summary, the major findings of this study were that targeted ablation of Ndst1 in smooth muscle cells results in altered biomechanical properties of aorta and differential expression of myosin and actin types and isoforms.
Multicenter evaluation of the antimicrobial activity for six broad-spectrum β-lactams in Venezuela: comparison of data from 1997 and 1998 using the Etest method

Abstract The minimum inhibitory concentrations of six broad-spectrum β-lactam antimicrobial agents were determined in 1998 by use of the Etest versus a total of 502 bacteria in seven Venezuelan hospital laboratories. These data were compared with results of a similar study performed in 1997. The organisms tested included 309 recent clinical isolates of Enterobacteriaceae, 70 Pseudomonas aeruginosa, 54 Acinetobacter species, and 69 oxacillin-susceptible Staphylococcus aureus. Extended spectrum β-lactamase production was noted among 30% of Klebsiella pneumoniae isolates. Hyperproduction of Amp C cephalosporinase producing resistance to ceftazidime and cefotaxime was observed with 10 to 37% of isolates of Enterobacter spp., Serratia spp., and Citrobacter freundii. The overall rank order of activity of the six β-lactams tested in this study against all clinical isolates was imipenem (96.6% susceptible) > cefepime (90.4%) > piperacillin/tazobactam (85.7%) > ceftazidime (73.5%) > cefotaxime (70.5%) > piperacillin (55.0%). These findings were very similar to those reported for 1997.
The Valence-State Energy of the Bivalent Oxygen Atom

A significant simplification in the discussion of the structure of molecules can be achieved by referring the energies of molecules not to the energies of their constituent atoms in any one of the stationary spectroscopic states of the isolated atoms, but instead to a hypothetical valence state of each atom. [1] The valence state of an atom is defined as that state in which it has the same electronic structure as it has in the molecule. Thus in the valence state the spins of the electrons that are used for forming bonds in a molecule are considered to resonate between positive and negative values, corresponding to the resonance of each bofiding electron with another electron of opposite spin in the atom with which the bond is formed. For the bivalent oxygen atom, with six L electrons, two orbitals, one mainly 2s in character and one 2p, are occupied by unshared pairs, and the other two orbitals, mainly 2p but with a small amount of s hybridization, are occupied by one bonding electron apiece, the spins of which are parallel 50 per cent of the time and antiparallel 50 per cent of the time. In the following paragraphs values of the energy of this bivalent state of the oxygen atom relative to the normal state of the isolated atom, 3P, are derived by four different methods. It is found that the four values agree reasonably well with one another, and their average value, 0.74 v.e., is indicated to be reliable to about 0.05 v.e.
Computerized tomographic abnormalities in patients with transient episodes of focal neurological dysfunction.

Abstract Forty patients with episodes of transient neurological dysfunction lasting less than 24 hr had abnormal CT scan findings. Eight patients had intracanial mass lesions and 32 had vascular lesions i.e. ischemic, infarction, hematoma. Seventeen patients had hypodense lesions consistent with tissue infarction; whereas 12 patients had isodense enhancing lesions consisting with tissue ischemia. In eight patients with isodense enhancing lesions, this was no neurological deterioration following carotid endarterectomy. In 3 patients who had transient ischemic attacks with CT evidence of hypodense lesions there was clinical and CT deterioration following carotid surgery.
RF interference at ground stations located in populated areas

Ground stations located in populated areas must contend with RF interference (RFI). While RF interference may disrupt occasional satellite contacts, disruption statistics in many cases are manageable. Thus the RF environment must be statistically characterized in order to predict availability and detect changes in the environment. An RF monitoring and recording system is essential to both characterize the RF environment and send alarms when interference appears. This paper presents a study of RF interference at the Satellite Communications Facility (SCF) located at The Johns Hopkins University Applied Physics Laboratory, and describes the impact of RF interference on the NASA Van Allen Probes mission. The area surrounding the SCF, located in Laurel, Maryland, was rural farmland when the SCF was commissioned in 1963. Since then the area has experienced tremendous commercial and residential development. Concurrent with this development RF activity has increased. In particular, increased RF interference is evident within the Van Allen Probes' S-band downlink allocation. The interference is due to other licensed parties, out-of-band commercial emissions, as well as natural phenomena. Some RFI sources have been identified, whereas others remain unknown. In this paper we describe the RF environment, and present a statistical characterization that shows that RFI has only a small impact on ground station availability. We also discuss operational considerations, including hand-shaking protocols and coordination with spectrum management.
Finding identities with the WZ method

Abstract Extending the work of Wilf and Zeilberger on WZ-pairs, we describe how new terminating hypergeometric series identities can be derived by duality from known identities. A large number of such identities are obtained by a Maple program that applies this method systematically.
Optimal parallel algorithms for polygon and point-set problems

In this paper we give parallel algorithms for a number of problems defined on polygons and point sets. All of our algorithms have optimal T(n) *P(n) products, where T(n) is the time complexity and P(n) is the number of processors used, and are for the EREW PRAM or CREW PRAM models. In addition, our algorithms provide parallel analogues to well known phenomena from sequential computational geometry, such as the fact that problems for polygons can oftentimes be solved more efficiently that point-set problems, and that one can solve nearest-neighbor problems without explicitly constructing a Voronoi diagram.
Effectiveness of Rhizobium as modified by mutation for resistance to antibiotics.

Many antibiotic-resistant mutants derived from effective strains ofRhizobium — mainlyR. leguminosarum andR. trifolii showed some loss of effectiveness on the homologous host. The frequency and degree of such changes in effectiveness depended on the type of antibiotic-resistance involved in the mutations. Resistance to streptomycin, spiramycin, chloramphenicol, or the tetracycline group of antibiotics was associated with little or no change. Resistance to D-cycloserine, novobiocin, vancomycin, bacitracin or penicillin was accompanied by partial or full loss of effectiveness in about one-half of the mutants. Full loss of effectiveness occurred most frequently among mutants selected for resistance to viomycin or neomycin. In contrast, restoration of the ability for effective symbiosis occurred in prototrophic revertants of a non-nodulating, purine-requiring mutant. Alteration of cell-wall characteristics is suggested as a possible basis for decrease of effectiveness among mutants resistant to those antibiotics, notablyD-cycloserine, which are known to inhibit cell-wall synthesis.
Apparent surface tension hysteresis of a dynamical system

Abstract The apparent surface tension hysteresis on the inside interface of an oscillating liquid spherical shell has been examined theoretically. The effect can be produced by at least four independent mechanisms: (i) The bulk liquid contains a soluble surfactant and sorption is diffusion-limited; (ii) sorption kinetics at the interface determine the exchange rates of the soluble surfactant between the surface and the bulk liquid; (iii) the surface layer is insoluble but exhibits viscoelastic properties; and (iv) the bulk liquid, independent of the interface, exhibits viscoelastic properties. In each case, the full dynamics involving the interface mechanically linked with the bulk liquid and induced by the shell oscillation are obtained and the apparent surface tension hysteresis characteristics are predicted. Applications to the behavior of lung surfactants in the alveoli of mammalian lungs are discussed in detail.
Optics (communication arising): Mechanism for 'superluminal' tunnelling

In their discussion of a mechanism that I proposed1 to explain the apparent superluminal (that is, faster than light) tunnelling of light pulses observed in photonic barrier experiments2,3,4,5, Buttiker and Washburn6 used an old 'reshaping' argument7 that is at variance with my model1 and is not supported by the bulk of the experimental tunnelling evidence. The mechanism I proposed agrees with experiment and resolves a long-standing paradox — namely, the lack of dependence of tunnelling time on barrier length for thick barriers (the Hartman effect)8,9.
Metal cluster topology 18. Flattening of hypoelectronic indium and thallium deltahedra in intermetallic phases containing alkali metals

Abstract Recently characterized intermetallic phases of the alkali metals and the heaviest icosogens In and Tl contain unusual hypoelectronic icosogen deltahedra having from 5 to 11 vertices. In these deltahedra the apparent electron deficiency is relieved by a distortion consisting of flattening selected vertices to allow participation of vertex d orbitals in addition to the usual sp 3 valence orbital manifold. The shapes of these In and Tl deltahedra suggest that such flattening occurs preferentially at degree 4 vertices in accord with the four-fold symmetry of the relevant ( n −1) d orbitals (e.g. d( x 2 − y 2 )). The prevalence of globally delocalized flattened 10- and 11-vertex In deltahedra in phases such as K 3 In 10 Zn and K 8 In 11 can be related to the strategic location of their degree 4 vertices, all of which are subject to flattening with retention of the symmetry of the undistorted deltahedron. A greater variety of structures are found in the Tl deltahedra where symmetry breaking of octahedral and tricapped trigonal bipyramidal Tl clusters can occur through selective flattening of degree 4 vertices of Tl 6 6− in KTl and Tl 9 9− in Na 2 K 21 Tl 19 , respectively. In addition, a variety of regular icosahedral Tl 12 clusters are known such as the Tl(Tl 12 ) 10− anions in Na 4 M 6 Tl 13 (M = K, Rb, Cs), the Tl(Tl 12 ) 11− anion in Na 3 K 8 Tl 13 , and the Na(Tl 12 ) 13− anion in Na 15 K 6 Tl 18 H in which the apparent deficiencies are relieved by introduction of interstitial atoms (Tl or Na) rather than flattening in accord with the absence of degree 4 vertices in the regular icosahedron.