cssi/SciSciGPT-SciSciNet huggingface dataset:
Isolation of a novel human papillomavirus (type 51) from a cervical condyloma.

The authors cloned the DNA from a novel human papillomavirus (HPV) present in a cervical condyloma. When DNA from this isolate was hybridized at high stringency with HPV types 1 through 50 (HPV-1 through HPV-50), it showed weak homology with HPV-6 and -16 and stronger homology with HPV-26. A detailed restriction endonuclease map was prepared which showed marked differences from the maps for other HPVs that have been isolated from the female genital tract. Reassociation kinetic analysis revealed that HPV-26 and this new isolate were less than 10% homologous; hence, the new isolate is a noel strain of HPV. The approximate positions of the open reading frames of the new strain were surmised by hybridization with probes derived from individual open reading frames of HPV-16. In an analysis of 175 genital biopsies from patients with abnormal Papanicolaou smears, sequences hybridizing under highly stringent conditions to probes from this novel HPV type were found in 4.2, 6.1, and 2.4% of biopsies containing normal squamous epithelium, condylomata, and intraepithelial neoplasia, respectively. In addition, sequences homologous to probes from this novel isolate were detected in one of five cervical carcinomas examined.
Development of Dominant Year Classes in a Yellow Perch Population

Abstract Abundance of young-of-the-year yellow perch in Oneida Lake, New York was estimated in 1959 through 1968 by shore seining in July and trawling in late summer. Seine and trawl catches were high in 1960, 1962, 1964, and 1968 and catches of age I+ perch in subsequent years confirmed that these were dominant year classes. Variation in numerical size of year classes was less in the first year than in the second which indicated a divergence in year class abundance. Estimates of mortality based on the catch in trawls from August to October confirmed that weak year classes generally experienced higher mortality than strong year classes, thus mortality was depensatory. Changes in year class bio-mass and estimates of perch consumed by the walleye population were consistent with the assumption that depensatory mortality was caused by predation.
Depletion of CD34+CD4+ cells in bone marrow from HIV-1-infected individuals

Abstract Pancytopenia as a consequence of bone marrow abnormalities is commonly seen in HIV-infected individuals. To examine the effect that HIV-1 has on hematopoietic cells, we compared hematopoietic properties of bone marrow samples from HTV+ patients at various stages of disease with bone marrow samples from uninfected donors. While the absolute number of recovered CD34+ cells and the cloning efficiency of these cells did not differ significantly in HIV+ donors, the percentage of CD34+ CD4+ cells was significantly depleted in late-stage HIV+ patients. We observed a direct correlation between the numbers of CD34+ CD4+ cells in the bone marrow and the peripheral CD4 count. Further characterization of the CD34+ CD4+ subpopulation demonstrated that these cells expressed lower levels of HLA-DR on their surface compared with CD34+ CD4- cells, suggesting an immature phenotype. We also found evidence for expression of HIV-1 coreceptors CXCR-4 and CKR-5 message and protein in CD34+ bone marrow cells. While this finding suggested that hematopoietic cells might be susceptible to HIV infection at an early stage of maturation, thus affecting different cell lineages as they matured, we did not find any evidence for infection of HIV in these cells. These data suggest that HIV affects early hematopoietic progenitor cells either directly or indirectly, and in particular CD34+ CD4+ cells. This finding has important implications for disease pathogenesis and for application of gene therapy approaches that use CD34+ hematopoietic cells. Biol Blood Marrow Transplant 1999;5(3):162-72.
Spline prewavelets for non-uniform knots

In this paper, we develop a framework suitable for performing a multiresolution analysis using univariate spline spaces of arbitrary degree and with non-uniform knot-sequences. To this end, we show, among other things, the existence of compactly supported prewavelets and of prewavelets that are globally supported, but decay exponentially. In each case we obtain a decomposition of a fine spline space as a sum of a coarse spline space plus a spline space spanned by prewavelets.
Some Comments on Assessment in U.S. Education

We do not know much about what assessment has accomplished but we know it has not brought about the reform of American Education. The costs and benefits of large scale mandated achievement testing are too complex to be persuasively reported. Therefore, educational policy needs to be based more on deliberated interpretations of assessment, experience, and ideology. Evaluation of assessment consequences, however inconclusive, has an important role to play in the deliberations.
Cell Cycle Arrest in Endometrial Carcinoma Cells Exposed to Gonadotropin-Releasing Hormone Analog

Gonadotropin-releasing hormone (GnRH) has been shown to have an inhibitory effect on the growth of several hormone-dependent human tumors. We have treated a human endometrial cancer cell line which expresses GnRH receptor with GnRH analog, D-Trp6-LHRH, in order to study whether there are differences in cell cycle kinetic response. Flow cytometric analysis revealed that cultured carcinoma cells showed a cell cycle arrest at the G1-S transition after treatment with 10 microM D-Trp6-LHRH for 36 h. Western blot analysis showed that the level of p16 protein was obvious following 24 h of D-Trp6-LHRH treatment. These results suggest that the mechanism by which GnRH inhibits the growth of endometrial carcinoma cells may include effects on cell cycle arrest.
Probe compounds to quantify cation exchange and complexation interactions of ciprofloxacin with soils.

Ciprofloxacin (CIP)−soil sorption interactions by surface complexation (via -COOH group) and cation exchange (-NH3+ group) were estimated by use of the structurally related probe compounds flumequine (FQ) (-COOH) and phenylpiperazine (PP) (-NH3+). Comparison of CIP and FQ sorption by surface complexation on goethite indicated a 0.7 times lower driving force for sorption, Kxs, for CIP than for FQ, with a model that assumed functional group interactions were enhanced by the hydrophobicity of the rest of the molecule. Similarly, Kxs was 9.5 times greater for CIP than for PP for sorption by cation exchange on kaolinite and montmorillonite. Use of the pure phase sorbent Kxs scaling factors between PP, FQ, and CIP for eight soils with a range of clay and oxide contents yielded total sorbed CIP concentrations that were within a factor of 2 (at pH 7.2) or less (at pH 5) of observed values. The estimated relative contributions of CIP cation-exchange versus complexation interactions increased for soils with increas...
A note on onset effects in binaural hearing

Various definitions of interaural ‘‘onset’’ delays in binaural stimuli have led to discrepant conclusions about the relative strength of onset versus ongoing cues. A distinction is offered here between gating (envelope‐onset) delays, and early fine‐structure (carrier) delays. This distinction, in conjunction with independent experimental results on the relative effectiveness of interaural envelope and carrier delays, leads to a reconciling interpretation.
Surface level trapping of air biota on the pacific ocean

Abstract On 3 cruises from 1967 to 1970, collections of fungal spores, hyphal fragments, pollen, and insect scales were made (using a Kramer-Collins spore sampler) in various areas of the Pacific Ocean. Cruise 1 was in the tropical Pacific Ocean south of Mexico; cruise 2, on the seas of Japan and Okhotsk; cruise 3, from Hawaii to Japan to Guam to Hawaii and from Tahiti to Panama to San Diego (California). The sampler was secured to the flying bridge in the forward part of the ship approx. 13 m above water level. Sampling was continuous at a rate of 1.4/m3 of air/h. Biotic particles decreased with distance from land. Concentrations of less than 3/m4 of air generally were reached at 300 to 1,300 km at sea west of North America, where air masses were of continental origin. Numbers of particles declined more sharply offshore from Hawaii, Guam, and other islands. Principal forms of biota in marine air included Cladosporium, aseospores, hyphal fragments, and pollen; however, composition (as well as concentration) of biota particles at ship-deck level in mid-ocean was comparable with that of the biota at altitudes above 200 to 300 m over the Pacific Ocean or over continental land masses of North America. No daily periodic pattern in the occurrence of biota in marine air was evident.
APPLICATION OF UNCERTAINTY ANALYSIS TO MAAP4 ANALYSES FOR LEVEL 2 PRA PARAMETER IMPORTANCE DETERMINATION

MAAP4 is a computer code that can simulate the response of a light water reactor power plant during severe accident sequences, including actions taken as part of accident management. The code quantitatively predicts the evolution of a severe accident starting from full power conditions given a set of system faults and initiating events through events such as core melt, reactor vessel failure, and containment failure. Furthermore, models are included in the code to represent the actions that could mitigate the accident by in-vessel cooling, external cooling of the reactor pressure vessel, or cooling the debris in containment. A key element tied to using a code like MAAP4 is an uncertainty analysis. The purpose of this paper is to present a MAAP4 based analysis to examine the sensitivity of a key parameter, in this case hydrogen production, to a set of model parameters that are related to a Level 2 PRA analysis. The Level 2 analysis examines those sequences that result in core melting and subsequent reactor pressure vessel failure and its impact on the containment. This paper identifies individual contributors and MAAP4 model parameters that statistically influence hydrogen production. Hydrogen generation was chosen because of its direct relationship to oxidation. With greater oxidation, more heat is added to the core region and relocation (core slump) should occur faster. This, in theory, would lead to shorter failure times and subsequent “hotter” debris pool on the containment floor.
James Brown Scott and the Rise of Public International Law

James Brown Scott played a key role in the growth of public international law in the United States from the 1890s to the 1940s. While little remembered today, he was well-known among his contemporaries as a leading spokesman for a new and important discipline. Scott rose from obscure middle-class origins to occupy a prominent and influential place as an international lawyer who shared his legal expertise with seven presidents and ten secretaries of state. By examining his life we gain insight into the establishment of public international law as a discipline and on the era when lawyers qua lawyers began to help shape American foreign policy.
Physician offered prayer and patient satisfaction.

Objective:While there is ongoing debate about the role of physician-offered prayer during the physician-patient encounter, many physicians feel inclined to include prayer in their practices. This randomized-controlled trial evaluated patients' acceptance of physician-offered prayer in a family practice setting, and the impact of physician-offered prayer on patient satisfaction with the physician-patient encounter.Method:Subjects were 137 patients in an urban, largely African American, Southeastern family medicine practice who were randomized to receive usual care plus an offer of physician-led prayer or usual care alone. Satisfaction surveys were administered following the clinical encounter. The outcomes of interest were the rate of acceptance of physician-offered prayer and the impact of the prayer offer on patient satisfaction. Personal characteristics and satisfaction scores for patients accepting prayer were compared to those for patients declining prayer.Results:Over 90% of patients accepted the off...
Validation of a laryngeal dissection module for phonomicrosurgical training.

Objectives: To validate the use of a new phonomicrosurgical trainer called the laryngeal dissection module. Study Design: The module used synthetic, multilayered vocal folds inside a model larynx mounted on a platform, a microscope, and microsurgical instruments. The study was designed to test the module's ability to differentiate novices from expert surgeons and to test the module's ability to improve novice performance with training. Methods: Expert (n = 5) and novice (n = 21) phonomicrosurgeons were instructed to remove a superficial ovoid lesion from a synthetic, right vocal fold. The task was assessed for total errors, total operating time, and injury to the superficial peripheral tissue, the lesion, and the deep tissue. Novice and expert performance was compared using an independent samples t test and a Fisher exact test. Subsequently, novices completed three practice trials and a posttraining trial, which was assessed for improvement compared with pretraining performance using a Wilcoxon signed rank test. Results: Experts completed the task with fewer total errors than novices (P < .001) and made fewer injuries to the oval lesion (P = .01). Novices improved performance with training, making fewer total errors in the posttraining trial (P = .003), reducing injury to the superficial peripheral tissue (P = .02), and taking less time to complete the task (P = .04). Conclusions: The laryngeal dissection module was validated as a surgical trainer. It was able to differentiate expert versus novice performance, and it improved novice performance through training. Laryngoscope, 119:211–215, 2009
In Search of the Holy Grail: Return on Investment Evaluation in Human Resource Development

The problem and the solution. Much of the human resource development (HRD) evaluation literature focuses on the Kirkpatrick four-level approach and emphasizes the importance of measuring the return on investment (ROI) of HRD initiatives or programs. This article argues that, in many cases, ROI does not provide the kind of information needed by decision makers. What is needed is a systems model that examines the effect of organizational and environmental factors on the intended outcomes of an HRD initiative or program. Such a model can help to frame any evaluation, including one that focuses on ROI.
The Commons, Game Theory, and Aspects of Human Nature that May Allow Conservation of Global Resources

Fundamental aspects of human use of the environment can be explained by game theory. Game theory explains aggregate behaviour of the human species driven by perceived costs and benefits. In the 'game' of global environmental protection and conservation, the stakes are the living conditions of all species including the human race, and the playing field is our planet. The question is can we control humanity's hitherto endless appetite for resources before we irreparably harm the global ecosystem and cause extinction of even more species? The central problem is that some proportion of the individuals or groups will behave selfishly. The inducement for using more than a fair share, or 'cheating', increases as that resource becomes rarer, thus the benefits of cheating increase. In addition, the total number of people is increasing, so the proportion of cheaters must decrease to even keep total resource use constant. Cost benefit analysis of the effect of regulation and incentives on potential cheaters may provide a rational approach to controlling environmental problems. While it is debatable that environmental values are constant across cultures, communal use of resources seems to follow global rules. Cooperative use and punishment of those who use more than their share appear to be ubiquitous in human societies. Schemes for controlling human impact on the global environment must take into consideration basic behaviours including development of social norms and the positive feedback created because resources become more valuable with increasing rarity leading to more incentive for consumption.
The effect of lovastatin on very low-density lipoprotein apolipoprotein B production by the liver in familial combined hyperlipidaemia

Overproduction of very low-density lipoprotein apolipoprotein B by the liver is a metabolic marker for familial combined hyperlipidaemia, a common inherited disorder of lipoprotein metabolism. Four subjects with familial combined hyperlipidaemia had rates of apolipoprotein B production which were 2–7 times normal, using a protocol in which [15N]nglycine was used to label newly synthesized hepatic proteins. Following 4–6 months of therapy with lovastatin, very low-density lipoprotein apolipoprotein B production in all four subjects had returned to the normal range. This demonstrates that lovastatin, an inhibitor of cholesterol biosynthesis, acts also to reduce the apparent production rate of apolipoprotein B by the liver.
Collision-induced dissociation in a tandem time-of-flight mass spectrometer with two single-stage reflectrons

A tandem time-of-flight mass spectrometer was developed to be used for the study of collision-induced dissociation (CID) products of peptides and small proteins. The instrument incorporates two single-stage reflectrons, the first to energy focus the precursor ions to be fragmented and the second to both energy focus and disperse the product ions formed in the collision cell. Single-stage rather than two-stage reflectrons were used because the overall transmission is higher, interferences with grid wire fields are minimized and the mass calibration of product ion spectra is exactly linear with time. The CID product ion spectra of rhodamine and several peptides were acquired and found to exhibit very similar fragmentation patterns to those acquired in the B/E linked scan mode of a magnetic sector mass spectrometer.
Execution of logic programs on a dataflow architecture

Logic programming is a mathematical formalism capable of expressing certain classes of problems in a non-procedural manner. Furthermore, logic programs do not presuppose a von Neumann computer architecture and are therefore inherently well suited to parallel computations. In this paper we consider a data-driven model for interpreting logic programs and investigate the architectural requirements necessary to support its implementation. It will be shown that the model is capable of exploiting the capabilities of highly-parallel dataflow architectures.
Active EM to reduce noise in activity recognition

Intelligent desktop environments allow the desktop user to define a set of projects or activities that characterize the user's desktop work. These environments then attempt to identify the current activity of the user in order to provide various kinds of assistance. These systems take a hybrid approach in which they allow the user to declare their current activity but they also employ learned classifiers to predict the current activity to cover those cases where the user forgets to declare the current activity. The classifiers must be trained on the very noisy data obtained from the user's activity declarations. Instead of asking the user to review and relabel the data manually, we employ an active EM algorithm that combines the EM algorithm and active learning. EM can be viewed as retraining on its own predictions. To make it more robust, we only retrain on those predictions that are made with high confidence. For active learning, we make a small number of queries to the user based on the most uncertain instances. Experimental results on real users show this active EM algorithm can significantly improve the prediction precision, and that it performs better than either EM or active learning alone.
Bound-State Residual Dipolar Couplings for Rapidly Exchanging Ligands of His-Tagged Proteins

The study of bound-state conformations of ligands interacting with proteins is important to the understanding of protein function and the design of drugs that alter function. Traditionally, transferred nuclear Overhauser effects (trNOEs), measured from NMR spectra of ligands in rapid exchange between bound and free states, have been used in these studies, owing to the inherent heavy weighting of bound-state data in the averaged ligand signals. In principle, residual dipolar couplings (RDCs) provide a useful complement to NOE data in that they provide orientational constraints as opposed to distance constraints, but use in ligand-binding applications has been limited due to the absence of heavy weighting of bound-state data. A widely applicable approach to increasing the weighting of bound-state data in averaged RDCs measured on ligands is presented. The approach rests on association of a His-tagged protein with a nickel-chelate-carrying lipid inserted into the lipid bilayer-like alignment media used in the acquisition of RDCs. The approach is validated through the observation of bound-state RDCs for the disaccharide, lactose, bound to the carbohydrate recognition domain of the mammalian lectin, galectin-3.
A formal ontology of knowing and knowledge

The paper presents a formalisation of one of the leading ontologies in Knowledge Management by the name of Formal Knowledge Management Ontology. After elaborating why the latter ontology is not a formal ontology in the sense of logic and how it might benefit from being logic-based, we detail a logical theory Formalised Formal Knowledge Management Ontology (F2KMO) that incorporates its main ideas and tenets. In particular, we specify the primitive, that is, undefined terms we assume, the axioms whose role is to fix the meanings of those terms, and a number of definitions that correspond to the definitions one may find in the latest exposition of Formal Knowledge Management Ontology. We show that F2KMO is consistent and prove its usefulness by defining the logical schema of a database based on the theory.
Associations among depressive symptoms, well-being, patient involvement, provider cultural competency, and treatment nonadherence: An exploratory study among university student-patients

Many students on US university campuses are underserved and undertreated for common mental health and medical conditions. The limited extent to which university students seek psychological and medical care when they need it has long been a problem. Among those who do seek care, treatment adherence appears to be an issue as well. However, few studies have examined factors that may be related to treatment nonadherence in university student-patients. The present survey study examined often-understudied constructs (i.e. patient involvement, treatment nonadherence, and provider cultural competency) in 243 university student-patients. Specifically, using a correlational research design, we examined the relations among depressive symptoms, well-being, patient involvement, cultural competency, and treatment nonadherence. Using multiple linear regression analysis, we also explored the extent to which the exploratory variables predicted treatment nonadherence separately and jointly. The current study revealed two i...
Technical surgical considerations for CEA directed second‐look operations and hepatic tumor excision

Surgical removal of recurrent metastatic colon and rectal cancer has provided many individuals with disease-free and treatment-free long-term survival of 5 or more years. Surgical removal of metastatic tumor from both lobes of the liver can be done with limited mortality and minimal complications when lesions are small and discovered early. Second-look operations should be performed when a persistently rising carcinoembryonic antigen is observed in the period after colorectal cancer resection, even when all other tests are negative. Repeat operations may be beneficial when all detectable disease was removed at the previous operation.
Studies on oxidative phosphorylation: evidence for multiple forms of factor B activity.

Abstract The appearance of energy transfer factor B (Factor B) activity in discrete fractions derived from heart mitochondrial extracts has been demonstrated. Two subfractions (Fractions 50-2 and 50-10), besides Factor B (in Fraction 100-10) stimulated the activity of the ammonia-EDTA particle (AE-particle) in oxidative phosphorylation, ATP-P 1 exchange and ATP-driven NAD + reduction by succinate (Succ-NAD + assay). Treatment of these factor preparations with p -Chloromercuriphenylsulfonate abolished their stimulatory activity in Succ-NAD + , indicating the involvement of thiol groups in their function. Based on sucrose density gradient centrifugation, the molecular weight of the active component in Fraction 50-10, which had the highest Factor B activity, was 47,000. In earlier work from this laboratory, the molecular weight of Factor B was found to be 29,000. Rabbit antiserum to Factor B showed precipitin bands with and completely inhibited the stimulation of the Succ-NAD + activity produced by Fractions 50-2, 50-10 and 100-2 in the presence of the AE particle.
Time-dependent gas holdup variation in an air-water bubble column

Abstract Time-dependent gas holdup variation in a two-phase bubble column is reported with air and tap water as the working fluids. The results indicate that time-dependent gas holdup is closely related to the water, whose quality is unsteady and changes, not only during the two-phase flow, but also during idle periods. The significance and characteristics of the time-dependent gas holdup variation are influenced by the bubble column operation mode (cocurrent or semi-batch), the sparger orientation, the superficial gas velocity, and the superficial liquid velocity. It is proposed that a volatile substance (VS), which exists in the water in very small concentrations and inhibits bubble coalescence, evaporates during column operation and results in a time-dependent gas holdup. The influence of bubble column operation mode, sparger orientation, superficial gas velocity, and superficial liquid velocity on the time-dependent gas holdup variation are explained based on their effects on bubble size, bubble contacting frequency and mixing intensity. This work reveals that regular tap water may cause significant reproducibility problems in experimental studies of air–water two-phase flows.
Correlation of yield strength with internal coherency strains for age-hardened Cu−Ni−Fe alloys

The maximum yield strengths for a given aging temperature were measured for age-hardened Cu−Ni−Fe alloys. The yield strengths were found to be proportional to the difference in cubic lattice parameters of unstressed precipitating phases and independent of other factors such as precipitate particle size and precipitate volume fraction. The yield strength dependence on lattice parameter differences alone indicated coherency stresses controlled the yield strengths. An analysis of the yield strength based only on internal coherency strains and stresses subsequently led to the derivation of an equation for the yield strength,i.e., $${_{}^{} }$$ where $$m$$ is the Taylor factor for converting from single crystal shear stress to polycrystalline tensile stress results,C ijare single crystal elastic stiffness constants and Δa is the difference in, anda 0 the average of the cubic lattice parameters of the precipitating phases. The equation indicates the yield strength is dependent only on the internal coherency strains and independent of particle size and precipitate volume fraction, as observed. The correlation of the experimentally measured yield strengths with the equation was quite good.
Epidermal growth factor traffic in lacrimal acinar cells.

Lacrimal gland acinar cells furnish a constitutive network of membrane vesicles between their basal-lateral plasma membranes and endomembrane compartments. This basal-lateral/endomembrane traffic may mediate normal acinar cell functions. However, it may also provide pathways for aberrant plasma membrane expression and secretion to the interstitium of autoantigen proteins. Additionally, it may be the source of aberrant MHC Class II molecules that mediate the presentation of processed autoantigen peptides. These phenomena could overwhelm peripheral tolerance mechanisms and promote the autoimmune responses of Sjogren’s syndrome.
Utility Theory With Probability Dependent Outcome Valuation: Extensions and Applications

This article extends Karni's (1992) Utility Theory with Probability Dependent Outcome Valuation (UTP-DOV) to accommodate a wider set of preferences, and applies the new representation to a variety of decision problems under risk. First, we present a new, more general, axiomatization of UTPDOV that renders the underlying intuition more transparent. Second, we develop sufficient conditions under which UTPDOV satisfies the betweenness and the ordinal independence axioms. Finally, we examine functional forms of the UTPDOV model that are consistent with several well known departures from the independence axiom.
The effects of inflammatory cytokines on lymphatic endothelial barrier function

Proper lymphatic function is necessary for the transport of fluids, macromolecules, antigens and immune cells out of the interstitium. The lymphatic endothelium plays important roles in the modulation of lymphatic contractile activity and lymph transport, but it’s role as a barrier between the lymph and interstitial compartments is less well understood. Alterations in lymphatic function have long been associated with edema and inflammation although the integrity of the lymphatic endothelial barrier during inflammation is not well-defined. In this paper we evaluated the integrity of the lymphatic barrier in response to inflammatory stimuli commonly associated with increased blood endothelial permeability. We utilized in vitro assays of lymphatic endothelial cell (LEC) monolayer barrier function after treatment with different inflammatory cytokines and signaling molecules including TNF-α, IL-6, IL-1β, IFN-γ and LPS. Moderate increases in an index of monolayer barrier dysfunction were noted with all treatments (20–60 % increase) except IFN-γ which caused a greater than 2.5-fold increase. Cytokine-induced barrier dysfunction was blocked or reduced by the addition of LNAME, except for IL-1β and LPS treatments, suggesting a regulatory role for nitric oxide. The decreased LEC barrier was associated with modulation of both intercellular adhesion and intracellular cytoskeletal activation. Cytokine treatments reduced the expression of VE-cadherin and increased scavenging of β-catenin in the LECs and this was partially reversed by LNAME. Likewise the phosphorylation of myosin light chain 20 at the regulatory serine 19 site, which accompanied the elevated monolayer barrier dysfunction in response to cytokine treatment, was also blunted by LNAME application. This suggests that the lymphatic barrier is regulated during inflammation and that certain inflammatory signals may induce large increases in permeability.
Utilizing distance distribution in determining topological characteristics of multi-hop wireless networks

Understanding the topological characteristics of communications networks is essential to the design and operation of such networks. Accordingly, the researchers have been analyzing the topological characteristics of various networks. In this paper, we focus on multi-hop wireless networks with uniformly distributed nodes in 2D and 3D environments. Using the geometrical relations in 2D, researchers have provided analytical formulas for some topological characteristics. However, generalizing this approach to 3D is difficult as it requires to carefully analyze several geometrical relations that overlap. Instead, we consider the distance distribution between two random points, which has been extensively studied in both 2D and 3D. Using these important results, we derive analytical formulas for various topological characteristics in both 2D and 3D. Using simulations, we verify the correctness of our analytical formulas.
The Arabidopsis Abscisic Acid Response Locus ABI4 Encodes an APETALA2 Domain Protein

Arabidopsis abscisic acid (ABA)-insensitive abi4 mutants have pleiotropic defects in seed development, including decreased sensitivity to ABA inhibition of germination and altered seed-specific gene expression. This phenotype is consistent with a role for ABI4 in regulating seed responses to ABA and/or seed-specific signals. We isolated the ABI4 gene by positional cloning and confirmed its identity by complementation analysis. The predicted protein product shows homology to a plant-specific family of transcriptional regulators characterized by a conserved DNA binding domain, the APETALA 2 domain. The single mutant allele identified has a single base pair deletion, resulting in a frameshift that should disrupt the C-terminal half of the protein but leave the presumed DNA binding domain intact. Expression analyses showed that despite the seed-specific nature of the mutant phenotype, ABI4 expression is not seed specific.
Effects of sample preparation on bacterial colonization of polymers

Characterization of materials developed for medical usage frequently includes studies in which the materials are inoculated with bacteria in order to assess bacterial colonization and biofilm formation. Observed differences in bacterial growth are typically considered to be due to the material or the incubation conditions. To our knowledge, the method used to prepare the materials has generally not been considered with regard to its influence on bacterial colonization. The objective of this study was to determine the effects that various preparation methods exert on bacterial colonization of polymer disks. Polymer disks of the same dimethacrylate composition were photopolymerized: (1) between untreated glass slides, (2) between polyester release film, (3) between glass slides treated with an alkyl silane, (4) between glass slides treated with a perfluorinated silane, or (5) with one free surface in an argon-purged chamber. Surface chemistry was quantified using X-ray photoelectron spectroscopy, hydrophobicity was assessed by water contact angle, and topography was characterized using atomic force microscopy. The disks were inoculated with Streptococcus mutans for 4 h, fixed, and visualized using confocal laser scanning microscopy. Differences among all groups were found with regard to surface chemistry, hydrophobicity, topography, and bacteria morphology, density, and coverage, indicating that the method of sample preparation strongly affects both the surface properties and the initial bacterial colonization. Polymerization on untreated slides was selected as the preferred method of preparation due to minimal material transfer to the polymer and consistent, reproducible bacterial colonization.
Measurement of confined supersonic, 2-d jet lengths using the hydraulic analogy

In this study, inviscid, confined supersonic and subsonic stream interactions are studied using a hydraulic analog experiment. Specifically, the length of the first minimum location of the slipline is measured. Reasonable agreement is shown between a theoretical model and analog measurements. A method for extending the isentropic limited hydraulic analogy to model these inherently non-isentropic flows is also developed.
Phlebography of the lower extremity and pelvic region.

Abstract Extralong-field phlebograms are described. Lesser saphenous vein cutdown at the ankle for portal of entry of contrast material, a pressure injector delivering a large volume of contrast material at low pressure, and the extralong-field seriograph combine to produce crisp radiographs of diagnostic quality over a field of 51 inches. Availability of this method has increased our indications for phlebography in patients with suspected venous disease. Situations in which phlebography has been of greatest value are: 1. 1. Unexplained edema of either or both legs. 2. 2. Localization of perforating veins and acute thromboses in cases with stasis ulceration of the leg. 3. 3. Suspected thrombosis, particularly when pulmonary embolism has occurred in the absence of any physical findings localizing the source of the emboli. 4. 4. Demonstration of patency and therefore prognosis after repair of a severed deep vein.
Multiple Resistance Strategies: How African American Women Cope With Racism and Sexism.

This qualitative study of a community sample of 196 African American women aimed to identify the coping strategies that Black women use to manage the stress of racism and sexism. The findings revea...
Two Forms of UvrC Protein with Different Double-stranded DNA Binding Affinities *

Abstract Using phosphocellulose followed by single-stranded DNA-cellulose chromatography for purification of UvrC proteins from overproducing cells, we found that UvrC elutes at two peaks: 0.4 m KCl (UvrCI) and 0.6 m KCl (UvrCII). Both forms of UvrC have a major peptide band (>95%) of the same molecular weight and identical N-terminal amino acid sequences, which are consistent with the initiation codon being at the unusual GTG site. Both forms of UvrC are active in incising UV-irradiated, supercoiled φX-174 replicative form I DNA in the presence of UvrA and UvrB proteins; however, the specific activity of UvrCII is one-fourth that of UvrCI. The molecular weight of UvrCII is four times that of UvrCI on the basis of results of size exclusion chromatography and glutaraldehyde cross-linking reactions, indicating that UvrCII is a tetramer of UvrCI. Functionally, these two forms of UvrC proteins can be distinguished under reaction conditions in which the protein/nucleotide molar ratio is >0.06 by using UV-irradiated,32P-labeled DNA fragments as substrates; under these conditions UvrCII is inactive in incision, but UvrCI remains active. The activity of UvrCII in incising UV-irradiated, 32P- labeled DNA fragments can be restored by adding unirradiated competitive DNA, and the increased level of incision corresponds to a decreased level of UvrCII binding to the substrate DNA. The sites of incision at the 5′ and 3′ sides of a UV-induced pyrimidine dimer are the same for UvrCI and UvrCII. Nitrocellulose filter binding and gel retardation assays show that UvrCII binds to both UV-irradiated and unirradiated double-stranded DNA with the same affinity (K a, 9 × 108/m) and in a concentration-dependent manner, whereas UvrCI does not. These two forms of UvrC were also produced by the endogenousuvrC operon. We propose that UvrCII-DNA binding may interfere with Uvr(A)2B-DNA damage complex formation. However, because of its low copy number and low binding affinity to DNA, UvrCII may not interfere with Uvr(A)2B-DNA damage complex formation in vivo, but instead through double-stranded DNA binding UvrCII may become concentrated at genomic areas and therefore may facilitate nucleotide excision repair.
Excavations at Tikal, Guatemala: The Work of William R. Coe

Excavations in the Great Plaza, North Terrace and North Acropolis of Tikal.Tikal Report No. 14. WILLIAM R. COE. Philadelphia: The University Museum, University of Pennsylvania, 1990. Volumes. Mil, 1007. xlix, xxiii, xi pp.; Volumes IV-VI, Figures 1-333. $395.00 (cloth). ISBN 0-934718-66-0.
The complexity of mitochondrial translation products in mammalian cells

Abstract The complexity of mitochondrial translation products in mouse liver and Ehrlich ascites tumor cells have been studied using a mitoplast system active in 35S methionine incorporation. Electrophoretic analysis on gradient polyacrylamide-SDS gels and urea-SDS gels under highly dissociating conditions show that both of the mitochondrial systems synthesize about 22 polypeptides. Many of these 35S labeled products compare with the polypeptides predicted by the DNA sequence analysis data reported by Anderson et al. (1).
On the existence of the β→α m transformation in the alloy systems Ti-Ag, Ti-Au, and Ti-Si

The existence of the β (bcc) to αim (hcp) massive transformation is demonstrated in three titanium-base eutectoid systems: Ti-Ag, Ti-Au, and Ti-Si. Confirmation is accomplished through optical microscopy and phase composition analysis by EDAX microprobe, supplemented by transmission electron microscopy. In these three alloy systems, the characteristics of the massive transformation were found to be quite similar, with very irregularly shaped αm grains consuming most or all the parent grains during moderate to rapid quenching from the β region. The transformation occurs at compositions well into the hypereutectoid region in the Ti-Ag system but is confined mainly to hypoeutectoid alloys in Ti-Au and Ti-Si.
Prospective comparison of contact with noncontact Nd:Yag laser therapy for palliation of esophageal carcinoma.

Twenty patients with dysphagia due to inoperable esophageal cancer were randomized to receive either contact or noncontact endoscopic laser treatment. Treatment groups were similar with respect to age, dysphagia score, and tumor dimensions. The median number of initial treatment sessions was two in both groups, and the median treatment times per session were 23 mn (range, 12 to 55 min) in the contact group and 19 min (range, 5 to 28 min) in the noncontact group. Median dysphagia scores were also similar in both groups 1 month after laser treatment, and no difference was apparent in the duration of palliation. There were no patient complications attributable to laser therapy, but damage to the laser wave guide occurred in three contact sessions and two noncontact sessions. These data suggest no advantage for the contact method of endoscopic Nd:YAG laser palliation of esophageal carcinoma with respect to number of treatment sessions, relief of dysphagia, or occurrence of complications.
Activation of the p21-activated protein kinases from neutrophils with an antibody that reacts with the N-terminal region of Pak 1.

Abstract Neutrophils contain two renaturable p21-activated protein kinases (Paks) with molecular masses of ca. 69 and 63 kDa that undergo rapid activation upon stimulation of these cells with the chemoattractant fMet-Leu-Phe. We now report that these kinases undergo a massive, ATP-dependent activation in lysates of unstimulated neutrophils during immunoprecipitation with an antibody generated to residues 2–21 of the N-terminal region of Pak1. This activation was specific as it was completely blocked by a peptide that corresponds to residues 2–21 of Pak1 and was not observed with an antibody generated to the C-terminal region of Pak 1. The properties of the Paks activated with the antibody were virtually identical to those observed for these kinases from stimulated neutrophils, or activated in vitro with Rac-GTPγS plus ATP. These data indicate that perturbation of the N-terminal region of Pak can trigger activation of this enzyme, and that both the 69 and 63 kDa kinases may represent forms of Pak 1 that differ in their content of phosphate. © 1997 Federation of European Biochemical Societies.
Pulsed performance of a steam reaction jet.

Abstract : The dynamic propulsive performance of a saturated steam reaction jet is analyzed and compared with the results of laboratory experiments. The vacuum thrust levels investigated range from 1 to 15 millipounds. The transient processes, which dominate the short-pulse or limit-cycle mode of thruster operation, are formulated and show good correlation with the data. The apparatus, procedures, and techniques required to obtain accurate test results for a low thrust, dynamic mode of operation are described. Impulse bit size, steam consumption, and specific impulse are characterized in terms of thruster geometry, gas properties, and command pulse width to provide a systematic basis for design. System limitations are discussed and design criteria necessary for successful spacecraft installation are provided. A comparison is made between the system performance of the steam reaction jet and the system performance of six different propellants. The results indicate that steam provides fairly high performance and may be attractive for certain spacecraft applications. (Author)
Active vibration control during deployment of space structures

Abstract Active vibration control during deployment of the NASA Solar Array Flight Experiment (SAFE) structure is considered in this study. The equations of motion of the SAFE structure are derived using Hamilton's principle. The approach to damp out the deployment-induced vibration is to use a force actuator located at the tip of the structure. Two different control strategies are investigated. In the first, the deployment-induced vibration is actively controlled from 70% to 100% deployment. In the second, the force actuator is turned on for a short period of time when the deployment reaches 70% and 100%. Both strategies make use of the linear regulator theory with a prescribed degree of stability. Simulated results presented show that both strategies damp out the deployment-induced vibration effectively. However, the second control system is simpler to design and implement and is, therefore, a more practical choice.
Current topics in ESR dating

Abstract After over 25 years, the use of electron spin resonance (ESR) is well-established in dating sites of geological, paleontological and archaeological interest. Like any scientific technique, there have been changes in understanding and in methodology. Improvements have not, however, changed the observation that external dose calculations are still a significant source of uncertainty in ages. Examples from Europe, Africa and the Americans illustrate this point. For Pradayrol Cave (France), the occupation age, 330 ka, is unchallenged, making this the oldest known Neanderthal site in France. For Roc de Marsal, also in France, on the other hand, discrepancies between TL and sedimentary dose rates imply substantial differences in interpretation. In the Western Egyptian Desert, where artifacts and datable material are not well-correlated, the dating results show consistency with expectations based on global climate change, even in deflated sites. Climate change is also the question in geological studies in the Bahamas where, despite concerns about cosmic dose history, ESR dates confirm other evidence for sea level changes. We show that an uncertain age is not the same as an impossible one.
Propagation of short fatigue cracks

AbstractFatigue crack propagation in engineering materials has been the subject of considerable research, and extensive review articles have appeared over the past several years. Most of these investigations focused on the behaviour of ‘long’ fatigue cracks, even though the characteristics associated with the extension of small cracks in metals and alloys remain relatively unexplored, despite their unquestionable importance from an engineering standpoint. In this review, the mechanics and micromechanisms of the subcritical growth of short fatigue cracks are examined, and aspects of their propagation behaviour are contrasted with those of long cracks in terms of fracture mechanics, microstructure, and environment. Cracks are defined as being short (i) when their length is small compared to relevant microstructural dimensions (a continuum mechanics limitation), (ii) when their length is small compared to the scale of local plasticity (a linear elastic fracture mechanics limitation), or (iii) when they are s...