cssi/SciSciGPT-SciSciNet huggingface dataset:
Postoperative Chylothorax After Thoracoabdominal Aortic Aneurysm Repair.

Chylothorax is a potentially deadly complication that can occur after thoracoabdominal aortic aneurysm (TAAA) repair. We describe our contemporary experience (2005-2014) with this complication, our efforts to identify perioperative variables associated with it, and our attempts to assess treatment outcomes. We reviewed the records of 1092 consecutive patients who underwent TAAA repair between 2005 and 2014. Standard bivariate analysis was used to test for between-group differences. Eleven patients (0.9%) developed postoperative chylothorax. Nonoperative management was used in 8 of these patients (73%); 1 patient died after a lengthy hospital stay (297 days). The other 3 patients required thoracotomy with direct ligation; 1 of these patients required a second operation. Patients who developed chylothorax appeared to be similar to other patients in age, sex, extent of aneurysm, and metabolic or cardiovascular comorbidities. Patients who developed postoperative chylothorax were more likely to require drainage of a pleural effusion ( P = 0.005), tracheostomy ( P = 0.02), and longer stays in the intensive care unit (median, 6 [2-24] days, P P = 0.001), and these patients were more likely to develop a graft infection (n = 2, P
Teacher-Student Relationships and Engagement: Conceptualizing, Measuring, and Improving the Capacity of Classroom Interactions

Classrooms are complex social systems, and student-teacher relationships and interactions are also complex, multicomponent systems. We posit that the nature and quality of relationship interactions between teachers and students are fundamental to understanding student engagement, can be assessed through standardized observation methods, and can be changed by providing teachers knowledge about developmental processes relevant for classroom interactions and personalized feedback/support about their interactive behaviors and cues. When these supports are provided to teachers’ interactions, student engagement increases. In this chapter, we focus on the theoretical and empirical links between interactions and engagement and present an approach to intervention designed to increase the quality of such interactions and, in turn, increase student engagement and, ultimately, learning and development. Recognizing general principles of development in complex systems, a theory of the classroom as a setting for development, and a theory of change specific to this social setting are the ultimate goals of this work. Engagement, in this context, is both an outcome in its own right and a mediator of impacts that teachers have on student outcomes through their interactions with children and youth. In light of this discussion, we offer suggestions or directions for further research in this area.
Positron Emission Tomography and Single-Photon Emission Tomography in the Diagnosis of Parkinson’s Disease

Parkinsonian symptoms are associated with a number of neurodegenerative disorders, such as Parkinson’s disease, multiple system atrophy, and progressive supranuclear palsy. Positron emission tomography (PET) and single-photon emission tomography (SPECT) now are able to visualize and quantify changes in cerebral blood flow, glucose metabolism, and neurotransmitter function produced by parkinsonian disorders. Both PET and SPECT have become important tools in the differential diagnosis of these diseases and may have sufficient sensitivity to detect neuronal changes before the onset of clinical symptoms. Imaging is now being used to elucidate the genetic contribution to Parkinson’s disease and in longitudinal studies to assess the efficacy and mode of action of neuroprotective drug and surgical treatments.
Rapid-rate thermophilic, single-stage and two-phase methane fermentation of synfuel-industry wastewaters.

Thermophilic (55°C) anaerobic digestion of wastewaters from wet carbonization of Minnesota peat was conducted in a simple, upflow digester at an HRT of one day to provide a methane yield of 0.20 SCM/kg VS added and a BOD 5 reduction of 85%. Carbonization of Maine peat conducted for a much longer duration of thermal treatment produced recalcitrant and potentially toxic end products that reduced the biodegradability of wastewaters. Methane fermentation of the Maine-peat wet-carbonization waste was inhibited at an HRT of one day in the single-stage digester. However, two-phase digestion with separate acid-phase fermentation to promote hydrolytic degradation of toxic end products followed by separate methane fermentation at an HRT of 2 days exhibited a methane yield of 0.21 SCM/kg VS added and a BOD 5 reduction of 76%. Volatile fatty acids profiles along the depths digesting cultures indicated that single-stage and two-phase digestion could be accomplished at one-half the reactor residence times (one day for single-stage and three days for two-phase) used in this research.
Emerging RNA Suppression Technologies to Protect Citrus Trees From Citrus Greening Disease Bacteria

Abstract Research on the development of RNA-suppressing technologies, which include RNA interference, (RNAi), and the application of RNA suppression using cell-penetrating peptide Morpholinos, PPMOs, for suppressing pests and pathogens are briefly presented. Due to the extensive nature of RNAi and antisense oligonucleotide research, readers are directed to this review to obtain a more in-depth understanding of each field of study. Genomic resources and websites for dataset downloads and free access are listed to facilitate a broader community collaboration to develop solutions for this complex Liberibacter pathosystem. Strategies for gene drive and psyllid population modification or replacement, with Wolbachia or CRISPR/Cas9-based alterations, have continued to gain interest and are being developed ( Champer et al., 2016 , Gantz and Akbari, 2018 , Peters et al., 2016 ).
Simulation and Experiment Waveform Comparison for Undersea Pulsed Laser in Application to Target Localization

This study has the objective of assessing the feasibility of using LiDAR (Light Detection and Ranging) and laser communications techniques for localization of moving undersea targets using coordinated multiple UUV operations. This coordination includes creating an array of multiple cooperative UUVs to create a baseline system that is interconnected and spans a ranged area. The primary importance is the detection of the reflected laser pulse from the target in the presence of overlapping multiple scattering signal from the natural background particle field of coastal waters. This signal must be detectable to derive an accurate time of arrival (TOA) for ranging and tracking purposes. To properly simulate the complexities of real world underwater communication, a model was created that complies to natural variation and complexity, while still allowing for a controlled environment. To meet these standards, a simulation recreates a similar setup and operations method as a controlled experiment. Tested in simulation and experiments are the expected characteristic waveforms for monostatic and bistatic transmitter via receiver geometry. With the data collection of expected delays, scattering and target reflection the result is to create a proficient localization system model for real world application for a range of distances and turbidity. Simulation results are compared with controlled experimental results regarding: expected waveform similarities, target impulse response and receiver geometries while practical hardware constraints ensures the feasibility of target detection in real world application. Experiments were conducted in reflection to simulation parameters to show validation of the simulation itself, as well, to compare and ensure reliable waveform and TOA. Presented is the comparison between ideal simulation and the real-world TOA waveforms of similar scenarios with their application to localization and accurate target positioning in a three-dimensional plane. Localization techniques include the multilateration equation referred to as Fang’s method. A statistical analysis of how this method performs is also presented in application to the cooperative UUV system for accuracy and precision. The denouement from the simulations and experiments presented are to create a robust localization model which accounts for differentiating propagation path geometry, water turbidity, and target orientation.
A randomized clinical trial evaluating the efficacy of a brief alcohol intervention supplemented with a substance-free activity session or relaxation training.

Objective Behavioral economic theory suggests that a reduction in alcohol use is most likely when there is an increase in rewarding substance-free activities. Anxiety has also been linked to heavy drinking, and strategies to reduce anxiety may enhance alcohol interventions. The goal of this 2-site randomized controlled clinical trial was to evaluate the efficacy of a brief alcohol intervention that was supplemented with either a behavioral economic substance-free activity session (SFAS) or a relaxation training (Relaxation training [RT]) session. Method Participants were 393 college students (61% female, mean age = 18.77 years) who reported 2 or more past-month heavy drinking episodes. Participants were randomized to 1 of 3 conditions: (a) assessment; (b) alcohol brief motivational intervention (BMI) plus SFAS; or (c) BMI plus RT. Both treatment conditions included 2 in-person sessions plus a phone booster session. Outcomes were evaluated 1-, 6-, 12-, and 16-months postintervention. Results Generalized linear mixed models indicated that the combination of a BMI plus either the SFAS or RT was associated with significant reductions in alcohol use and problems across the 16-month follow-up compared with assessment only. There were no significant differences between the two active treatment conditions. Changes in proportional reinforcement from substance-related activities, and protective behavioral strategies mediated treatment effects. Conclusion Two-session (plus booster) interventions that combine BMI and either substance-free activity enhancement or RT can result in enduring reductions in alcohol misuse among college drinkers. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
Thickness-dependent charge transport in exfoliated indium selenide vertical field-effect transistors

As a layered, two-dimensional material with high charge carrier mobility and photoresponsivity, exfoliated indium selenide (InSe) is being actively studied for a variety of optoelectronic applications. While significant effort has been devoted to characterizing the in-plane electronic properties of InSe, charge transport in the out-of-plane direction has been underreported despite its importance in vertical field-effect transistors, photodetectors, and related van der Waals heterostructure devices. Here, we fill this knowledge gap by performing variable temperature and variable thickness charge transport measurements in the out-of-plane direction for exfoliated InSe crystals. A vertical field-effect transistor geometry is utilized with a bulk metal top contact and single-layer graphene bottom contact such that electrostatic gating can be performed via the underlying Si substrate. In contrast to lateral InSe transistors, vertical InSe transistors show decreasing conductance at low temperatures, which is explained by the temperature dependence of tunneling and field-emission currents. While thinner InSe crystals are dominated by Fowler-Nordheim tunneling, thicker InSe crystals show increasing contribution from thermionic emission. In addition, the graphene/InSe barrier height can be modulated by the gate potential, resulting in vertical field-effect transistor current switching ratios up to 104. Overall, this study provides fundamental insight into the out-of-plane electronic properties of exfoliated InSe, which will inform ongoing efforts to realize ultrathin InSe device applications.
Experience with head-mounted virtual reality (HMD-VR) predicts transfer of HMD-VR motor skills

Immersive, head-mounted virtual reality (HMD-VR) has the potential to be a useful tool for motor rehabilitation. However, when developing tools for rehabilitation, it is essential to design interventions that will be most effective for generalizing to the real world. Therefore, it is important to understand what factors facilitate transfer from HMD-VR to non-HMD-VR environments. Here we used a well-established test of skilled motor learning, the Sequential Visual Isometric Pinch Task (SVIPT), to train healthy individuals in an HMD-VR environment. We examined whether learned motor skills transferred to a more conventional (non-HMD-VR) environment and what factors facilitated transfer. Our results suggest that on average, learned motor skills from this task transfer from an immersive virtual environment to a conventional environment; however, some individuals did not transfer the learned motor skills. We then examined individual differences between those that did show transfer and those that did not. We found that individuals who had previous exposure to HMD-VR were more likely to transfer their learned motor skills than those who did not. Individual differences in previous exposure to HMD-VR environments prior to training may serve as a predictor to whether learned motor skills will transfer out of HMD-VR.
A Multi-scale Analysis of Urban Warming in Residential Areas of a Latin American City: The Case of Mérida, Mexico:

This study represents a novel attempt to analyze the relationship between Latin American city structure and residential-scale ambient temperatures. Using statistical analysis, we assess the relatio...
Effect of Confinement on Properties and Characteristics of Alkali-Silica Reaction Gel

This paper studies how steel microfibers can generate confinement of the resulting alkali-silica reaction (ASR) gel. ASR gel, which develops as a byproduct between certain types of aggregates and the cement paste, can lead to crack formation in concrete. As the amount of local confinement found within the material determines the degree of damage, the research also investigates how confinement affects the formation and characteristics of the ASR gel. Both solid and liquid forms of ASR gel are studied, via microprobe analysis (to determine chemical composition) and inductive coupled plasma spectroscopy. The research also measures the viscosity of the liquid alkali-silicate solution. Results show that the use of steel microfibers in controlling cracks leads to a chemo-mechanical confinement of the ASR gel. The authors note that this type of confinement reduces volumetric expansion, ASR gel formation, and the reactivity of the reactive aggregate.
Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells.

Conjugated polymers with ionic pendant groups (CPEs) are receiving increasing attention as solution-processed interfacial materials for organic solar cells (OSCs). Various anionic CPEs have been successfully used, on top of ITO (Indium Tin Oxide) electrodes, as solution-processed anode interlayers (AILs) for conventional devices with direct geometry. However, the development of CPE AILs for OSC devices with inverted geometry is an important topic that still needs to be addressed. Here, we have designed three anionic CPEs bearing alkyl-potassium-sulfonate side chains. Their functional behavior as anode interlayers has been investigated in P3HT:PC61BM (poly(3-hexylthiophene): [6,6]-phenyl C61 butyric acid methyl ester) devices with an inverted geometry, using a hole collecting silver electrode evaporated on top. Our results reveal that to obtain effective anode modification, the CPEs’ conjugated backbone has to be tailored to grant self-doping and to have a good energy-level match with the photoactive layer. Furthermore, the sulfonate moieties not only ensure the solubility in polar orthogonal solvents, induce self-doping via a right choice of the conjugated backbone, but also play a role in the gaining of hole selectivity of the top silver electrode.
Proton pump inhibitor use (PPI) in patients treated with immune checkpoint inhibitors (ICI) for advanced cancer: Survival and prior therapy.

2633Background: Emerging data suggest that concomitant medications (CM) influence response to ICI. CM impact the host microbiome which may mitigate tumor-immune responsiveness. PPI use in patients ...
Coherent confocal light scattering spectroscopic microscopy evaluates cancer progression and aggressiveness in live cells and tissue

The observation of biological structures in live cells beyond the diffraction limit with super-resolution fluorescence microscopy is limited by the ability of fluorescence probes to permeate live cells and the effect of these probes, which are often toxic, on cellular behavior. Here we present a coherent confocal light scattering and absorption spectroscopic microscopy that for the first time enables the use of large numerical aperture optics to characterize structures in live cells down to 10 nm spatial scales, well beyond the diffraction limit. Not only does this new capability allow high resolution microscopy with light scattering contrast, but it can also be used with almost any light scattering spectroscopic application which employs lenses. We demonstrate that the coherent light scattering contrast based technique allows continuous temporal tracking of the transition from non-cancerous to an early cancerous state in live cells, without exogenous markers. We also use the technique to sense differences in the aggressiveness of cancer in live cells and for label free identification of different grades of cancer in resected tumor tissues.
Stolen Valor and the First Amendment: Does Trademark Infringement Law Leave Congress an Opening?

This paper elaborates an argument the authors presented in an amicus brief filed in United States v. Alvarez, the "Stolen Valor" case. The paper contends that Congress could constitutionally protect the Congressional Medal of Honor as a collective membership mark by means of trademark infringement legislation.
vemPEBB: Rapid PEBB Thermal Management Tool

We introduce VEMPEBB, a rapid power electronics building block (PEBB) thermal management tool tailored for multi-fidelity PEBB modeling within the set-based design (SBD) framework. In accordance with the SBD philosophy, the proposed tool is generalized and applicable to a wide range of PEBB prototypes of different topologies, design requirements, and constraints. VEMPEBB has been developed based on the volume element modeling approach, wherein the computational domain is discretized with lumped hexahedral elements to which the conservation of energy is applied. The spatial dependency of the model is incorporated into the mesh generated using ray-tracing algorithms, and the velocity field is assumed a priori or estimated based on the scaling laws to expedite computations while retaining sufficient accuracy. Furthermore, the tool enables rapid evaluation and prototyping of different external PEBB cooling solutions by either treating them as part of the computational domain or as spatiotemporal boundary conditions. This paper summarizes the mathematical formulation of VEMPEBB and its numerical verification against high-fidelity numerical simulations, and we also discuss its usage and practicality as a low-fidelity model within the SBD framework.
Retracing a Remembered Past: Methodological Remarks on Memory, History, and the Hebrew Bible

Historians of the southern Levant have increasingly made recourse to the concept of memory as an analytical tool to examine the past recounted within the Hebrew Bible. The intent of this article is to review current approaches toward memory among these historians in order to consider certain theoretical questions raised within this research. Most significant of these will be concerns related to the epistemological relationship that obtains between those ancient, literary memories outlined within these investigations and that past reconstructed through the techniques of modern historical inquiry. The epistemological differences perceived between the past claimed by memory and history leads to the contention that historians charged with interpreting the referential claims of ancient texts informed by a community’s shared memories must do so through a hermeneutical framework that is sensitive to memory’s distinct epistemological underpinnings. This study then concludes by advocating for a post-positivist interpretive approach that situates the referential claims of a remembered past alongside a constellation of ancient referents, textual and material, that attest to the place and time being recollected in order to trace out the semblances and dissimilarities that emerge.
Chapter 2C Electron microscopy: image processing and quantitative electron microscopy

Publisher Summary Image processing serves as an essential adjunct to high-resolution electron microscopic studies of biological specimens. These techniques have already been applied fruitfully in several animal virus systems and have the potential to contribute incisively to many others. Attaining higher resolution will depend on advances in specimen preparation and low-dose imaging methods. Scanning transmission electron microscopy (STEM) is a relatively novel imaging method that combines several major advantages for the observation of biological specimens with adequate contrast, without staining or shadowing with heavy metals. Among other potentialities of this kind of microscope, STEM dark-field images have already been found to be particularly useful for direct mass measurements of individual macromolecular complexes and for mass-mapping within such complexes. These capabilities should find many applications in structural virology.
In vivo site-directed mutagenesis using oligonucleotides

Functional characterization of the genes of higher eukaryotes has been aided by their expression in model organisms and by analyzing site-specific changes in homologous genes in model systems such as the yeast Saccharomyces cerevisiae. Modifying sequences in yeast or other organisms such that no heterologous material is retained requires in vitro mutagenesis together with subcloning. PCR-based procedures that do not involve cloning are inefficient or require multistep reactions that increase the risk of additional mutations. An alternative approach, demonstrated in yeast, relies on transformation with an oligonucleotide, but the method is restricted to the generation of mutants with a selectable phenotype. Oligonucleotides, when combined with gap repair, have also been used to modify plasmids in yeast; however, this approach is limited by restriction-site availability. We have developed a mutagenesis approach in yeast based on transformation by unpurified oligonucleotides that allows the rapid creation of site-specific DNA mutations in vivo. A two-step, cloning-free process, referred to as delitto perfetto, generates products having only the desired mutation, such as a single or multiple base change, an insertion, a small or a large deletion, or even random mutations. The system provides for multiple rounds of mutation in a window up to 200 base pairs. The process is RAD52 dependent, is not constrained by the distribution of naturally occurring restriction sites, and requires minimal DNA sequencing. Because yeast is commonly used for random and selective cloning of genomic DNA from higher eukaryotes such as yeast artificial chromosomes, the delitto perfetto strategy also provides an efficient way to create precise changes in mammalian or other DNA sequences.
Curves and surfaces in geometric modeling : theory and algorithms

1 Introduction 2 Basics of Affine Geometry 3 Introduction to the Algorithmic Geometry of Polynomial Curves 4 Multiaffine Maps and Polar Forms 5 Polynomial Curves as Be'zier Curves 6 B-Spline Curves 7 Polynomial Surfaces 8 Subdivision Algorithms for Polynomial Surfaces 9. Polynomial Spline Surfaces and Subdivision Surfaces 10 Embedding an Affine Space in a Vector Space 11 Tensor Products and Symmetric Tensor Products 12 Appendix 1: Linear Algebra 13 Appendix 2: Complements of Affine Geometry 14 Appendix 3: Topology 15 Appendix 4: Differential Calculus
Spatially Averaged Multi-Scale Models for Chemical Reactors

Abstract The classical homogeneous and catalytic reactor models such as CSTR, PFR, and two-phase models, make a priori assumptions on the length and time scales of diffusion, convection, and reaction and apply the conservation laws at the macroscopic level. This intuitive averaging leads to incorrect and often non-physical description of the small-scale mixing/diffusion effects, accumulation and reaction terms in the averaged form of the conservation laws. We consider the full convection–diffusion–reaction equations with homogeneous and catalytic reaction and spatially average them rigorously over small length/time scales using the Liapunov–Schmidt method. This results in low-dimensional averaged models defined in terms of multiple concentration and temperature modes (variables), each of which is representative of a physical scale of the system. These multi-mode models are markedly different from the classical reactor models and are hyperbolic for most cases of practical interest. While their solution requires a numerical effort that is comparable to that of the classical reactor models, they retain all the parameters and qualitative features of the full governing equations (within their region of convergence) and overcome the shortcomings of the classical models (such as dependence of effective transport coefficients on kinetics, inability to describe micromixing effects, infinite speed of propagation of signals even in convection dominated systems, etc). Examples are presented to illustrate and compare the predictions of the new averaged multi-mode models with those of the classical models.
Transplantation of brain cells assembled around a programmable synthetic microenvironment

Cell therapy is a promising method for treatment of hematopoietic disorders, neurodegenerative diseases, diabetes, and tissue loss due to trauma. Some of the major barriers to cell therapy have been partially addressed, including identification of cell populations, in vitro cell proliferation, and strategies for immunosuppression. An unsolved problem is recapitulation of the unique combinations of matrix, growth factor, and cell adhesion cues that distinguish each stem cell microenvironment, and that are critically important for control of progenitor cell differentiation and histogenesis. Here we describe an approach in which cells, synthetic matrix elements, and controlled-release technology are assembled and programmed, before transplantation, to mimic the chemical and physical microenvironment of developing tissue. We demonstrate this approach in animals using a transplantation system that allows control of fetal brain cell survival and differentiation by pre-assembly of neo-tissues containing cells and nerve growth factor (NGF)-releasing synthetic particles.
Approaches to the Rational Design of Enzyme Inhibitors

Selective inhibitors of enzyme-catalyzed reactions are widely used in both biochemical and medical science. The inhibitor may be used to block either a single enzyme or a metabolic pathway. The utility of an enzyme inhibitor as a mechanistic probe or a therapeutic agent will depend, in part, on the potency of the inhibitor and its specificity toward its target enzyme. These properties will, in turn, depend on the number and type of interactions the inhibitor makes with the enzyme and the overall mode of inhibition. Here we provide a concise overview of the forces involved in inhibitor binding, and a brief summary of the treatment of enzyme kinetic data. Enzyme inhibitors have been divided into two groups, reversible and irreversible, based on whether the inhibitor binds covalently to its target enzyme. Within these groups inhibitors have been classified on the basis of kinetics, structure, and mechanism. Examples are provided in all cases and, where possible, these are of inhibitors possessing therapeutic interest. The criteria for inclusion in each class of inhibitor are described, as well as the kinetic implications, with particular reference to the specificity of the inhibition. Treatment of the examples includes discussion of the design aspects and, if appropriate, a historical perspective that demonstrates the development of a rational approach to inhibitor design. Keywords: enzyme inhibitor; inhibition constant; IC50 value; multisubstrate analog; transition state analog; affinity label; mechanism-based inhibitor
Ground reaction forces in distance running

Abstract Ground reaction forces and center of pressure (C of P) patterns were studied in 17 subjects running at 4.5 ms −1 . The subjects were classified as rearfoot or midfoot strikers according to the location of the C of P at the time of first contact between foot and ground. The C of P path in the rearfoot group showed a continuous anterior movement during support while the C of P in most of the midfoot group migrated posteriorly during the first 20 ms of the support phase. Variability in both groups was most marked during early support. The mean peak to peak force components were 3 BW , 1 BW and 0.3 BW in the vertical, anteroposterior and mediolateral directions respectively. Consistent differences between groups were noted in all three components, but individual differences within a given group were also considerable. The C of P patterns are presented in conjunction with ground reaction force data, and the implications of the results in the areas of running mechanics, shoe design and sports injury are discussed.
Drug Distribution and Binding

The distribution of drugs in the body depends on their lipophilicity and protein binding. Low plasma binding or high tissue binding or high lipophilicity usually means an extensive tissue distribution. In pharmacokinetics, the distribution is described by the parameter V, the apparent volume of distribution. This parameter measures the relative distribution of drugs between tissue and plasma and depends on the plasma and tissue binding and the lipophilicity of the drug. If the distribution of drug throughout the body is slow, V in the terminal phase will also depend on the clearance of the drug. At equilibrium, V will theoretically not be lower than 7 L in a 70-kg person, but it has no upper limit. The extent to which a drug distributes affects the half-life of the drug and the fluctuation of the concentration at steady state on multiple dosing, but not the average steady-state concentration.
Terahertz Pioneer: Shenggang Liu “China's Father of Vacuum and Microwave Electronics”

Professor and President Shenggang Liu came into the world as the last of 11 children on December 26th, 1933 in Feidong, a part of Hefei city, approximately 100 km west of Nanjing. Since December 26th was already an auspicious birth-date claimed by the late Mao Zedong, an alternate birthday was considered to be politically more acceptable. December 25th was also taken by a well known historical figure—and who wants to celebrate a birthday on Christmas anyway—so December 21st became Shenggang Liu’s birthdate of record.
Long-Term Biological Damage: What is Known, and How Should that Influence Decisions on Response, Assessment, and Restoration?

ABSTRACT Immediate damage from an oil spill is usually obvious (oiled birds, oiled shoreline), but long-term damage to either fauna or habitat is more subtle, difficult to measure, difficult to evaluate, and hence often controversial. The question is, are too many of response decisions such as dispersant use or shoreline cleanup based on short-term acute toxicity models? Have long-term damage scenarios been discounted because of the inherent difficulty in deriving definitive answers? Experience with the Exxon Valdez oil spill is shedding new light on the potential for long-term damage. Government-funded studies demonstrated that oil persists in certain habitats for extended periods of time, such as the intertidal reaches of salmon streams, in soft sediments underlying mussel beds, and on cobble beaches armored with large boulders. Observation of long-term persistence of oil in some habitats is not new, but an increasing number of studies indicate that fauna may be chronically and significantly exposed to ...
An in vivo-in vitro alkaline DNA unwinding assay for hepatic DNA damage: Comparison with the alkaline sucrose gradient centrifugation technique

An in vivo-in vitro alkaline DNA unwinding assay for single-strand breaks and/or alkali-labile lesions in hepatic DNA is described. The assay involves isolation of hepatic nuclei from mice, alkaline denaturation and unwinding of hepatic DNA, separation of single- and double-stranded DNA by hydroxylapatite batch chromatography, and quantitation of DNA in chromatographic fractions by a fluorometric assay. The method allows for the sensitive detection of hepatic DNA damage following in vivo administration of xenobiotics. Using this procedure, DNA fragmentation was demonstrated in alkali after administration of as little as 0.5 mg/kg of N-nitrosodimethylamine (DMN) to male B6C3F1 mice. A comparison of this technique with a similar alkaline sucrose density gradient centrifugation assay demonstrated comparable limits of sensitivity for the two procedures.
The nature of naming errors in primary progressive aphasia versus acute post-stroke aphasia.

Objective: To compare the distribution of error types across subgroups of primary progressive aphasia and poststroke aphasia in different vascular locations. Method: We analyzed naming errors in 49 individuals with acute left hemisphere ischemic stroke and 55 individuals with three variants of primary progressive aphasia. Location of atrophy or ischemic stroke was characterized using MRI. Results: We found that distribution of error types was very similar across all subgroups, irrespective of the site or etiology of the lesion. The only significant difference across groups was the percentage of circumlocutions (F(7, 96) 3.02, p .005). Circumlocution errors were highest among logopenic variant PPA (24%) and semantic variant PPA (24%). Semantic coordinate errors were common in all groups, probably because they can arise from disruption of different cognitive processes underlying naming and, therefore, from different locations of brain damage. Conclusions: Semantic errors are common among all types of primary progressive aphasia and poststroke aphasia, and the type of error depends in part on the location of damage.
The use of stable isotope techniques to assess zinc metabolism

The refinement of techniques that can accurately measure small changes in zinc stable isotope ratios in biological samples provides new opportunities for advancing our understanding of human zinc metabolism. The feasibility of utilizing more than one zinc stable isotope label simultaneously is invaluable for more complex kinetic studies. These techniques are especially valuable for investigations of the regulation of Zn homeostasis in infants and in women during the reproductive cycle in whom problems with zinc nutriture may be relatively frequent and of concern for preand postnatal growth and development. Initially, these techniques have been applied to studying the role of the intestine in the maintenance of zinc homeostasis and have served to emphasize the importance of the modulation of fecal excretion of endogenous zinc. Application of stable isotope techniques to explore zinc metabolism beyond the intestinal tract is still limited but has considerable potential for advancing our understanding of zinc metabolism in health and disease.
Antifungal defense turns 17.

Fungal recognition occurs partially through the C-type lectin dectin-1. New studies show that dectin-mediated immune recognition of Candida albicans induces the differentiation of interleukin 17–producing T helper cells that express chemokine receptors characteristic of mucosal homing.
Enlarged parietal foramina

Enlarged parietal foramina (EPF) are a rare condition (less than 1 in 10,000) with no known sex or racial predominance.1 No known environmental factors are associated with EPF. EPF can be hereditar...
Theory of surface diffusion: Crossover from classical to quantum regime.

A theory is developed for adatom diffusion on surfaces, employing the memory function formalism. The diffusion constant is expressed in terms of static correlation functions which are computed via Monte Carlo path integrations. Our theory is valid at all temperatures in the high friction limit and indicates a sharp crossover from the classical Arrhenius regime at high temperatures to the quantum tunneling regime at low temperatures. Comparisons with experimental data are presented for the H/Ni(100) system.
Synthesis and cellular studies of PPIX-homing peptide conjugates

Five amphiphilic protoporphyrin IX-peptide conjugates bearing the sequences ATWLPPR, AAhexPQRRSARLSA and cERGDPhe conjugated via the propionic side chains, were synthesized and evaluated in vitro using two cell lines: human carcinoma HEp2 and human leukemia HL-60. All conjugates were found to have low dark- and photo-toxicities in both cell lines, and 3 to 10-fold higher accumulation was observed within HL-60 vs. HEp2 cells, depending on the nature of the peptide sequence. The preferential subcellular sites of localization for all conjugates were found to be the lysosomes in HEp2 cells, and the mitochondria in HL-60 cells, suggesting different mechanisms of cellular internalization.
Pressure driven digital logic in PDMS based microfluidic devices fabricated by multilayer soft lithography

Advances in microfluidics now allow an unprecedented level of parallelization and integration of biochemical reactions. However, one challenge still faced by the field has been the complexity and cost of the control hardware: one external pressure signal has been required for each independently actuated set of valves on chip. Using a simple post-modification to the multilayer soft lithography fabrication process, we present a new implementation of digital fluidic logic fully analogous to electronic logic with significant performance advances over the previous implementations. We demonstrate a novel normally closed static gain valve capable of modulating pressure signals in a fashion analogous to an electronic transistor. We utilize these valves to build complex fluidic logic circuits capable of arbitrary control of flows by processing binary input signals (pressure (1) and atmosphere (0)). We demonstrate logic gates and devices including NOT, NAND and NOR gates, bi-stable flip-flops, gated flip-flops (latches), oscillators, self-driven peristaltic pumps, delay flip-flops, and a 12-bit shift register built using static gain valves. This fluidic logic shows cascade-ability, feedback, programmability, bi-stability, and autonomous control capability. This implementation of fluidic logic yields significantly smaller devices, higher clock rates, simple designs, easy fabrication, and integration into MSL microfluidics.
Blood physiology during activity in the snakes Masticophis flagellum (colubridae) and Crotalus viridis (crotalidae)

Abstract 1. 1. Aspects of blood physiology (pH, blood buffer composition) were investigated in the snakes Masticophis flagellum (Colubridae) and Crotalus viridis (Crotalidae) during rest and maximal activity at 35°C. 2. 2. Though both species exhibit similar resting blood pH, during activity blood pH in Crotalus declined 0.28 pH units greater than did the pH of Masticophis blood. 3. 3. Superior control of blood pH in Masticophis is attributed to that species' well developed bicarbonate-carbonic acid blood buffering system, which is approx 1.5 × as active as the bicarbonate-carbonic acid buffering system of Crotalus. 4. 4. It is postulated that Masticophis utilizes its complex lung to facilitate function of the bicarbonate-carbonic acid buffering system by speeding the rate of CO2 elimination from the body.
General theory of holography

In this paper I propose a method of analysis general enough to encompass all proposed forms of holography, including coherent, incoherent, and modulated incoherent. The analysis shows that a coherent source is the only one giving uniformly good results on the basis of signal-to-noise (S/N) ratio. For incoherent and modulated incoherent sources the S/N ratio decreases as 1/N12, where N is the number of coherent elements in the source.
Hematopoietic stem cell transplantation using umbilical cord blood progenitors: review of current clinical results

Umbilical cord blood (CB) has been rapidly established as an alternative source of stem cells to bone marrow for allogeneic-related and unrelated hematopoietic transplantation. To date, almost 70 000 CB units are available for transplantation and more than 2000 CB transplants (CBT) have been performed, mostly in children, for the treatment of a variety of malignant and nonmalignant conditions. Considerable experience has been rapidly accumulated in this field and many aspects of CBT have been elucidated, while other questions remain unresolved. A concise review of the clinical results achieved after related and unrelated CBT is presented and discussed.
A possible comet and asteroid link in the formation of comets

IRAS data on particles in the asteroid belt and 'cirrus' clouds at large heliocentric distances are used as the bases for a model of ongoing comet production. It is noted that many particles in the solar system have a radiation pressure/gravitational attraction ratio of 0.5, a condition that holds true for particles in the asteroid belt. Collisionally disturbed into eccentric orbits, the particles could collect frosty grains in the outermost solar system. IRAS revealed the presence of many of these grains in the asteroid belt. It is numerically shown that the agglomeration of many subkilometer radius asteroids deflected into the outer solar system by orbital perturbations induced by Jupiter could provide a nucleating location for the outwardly-migrated grains. Techniques which could be employed to test the hypothesis are discussed.
A mobility and traffic generation framework for modeling and simulating ad hoc communication networks

We present a generic mobility and traffic generation framework that can be incorporated into a tool for modeling and simulating large scale ad~hoc networks. Three components of this framework, namely a mobility data generator (MDG), a graph structure generator (GSG) and an occlusion modification tool (OMT) allow a variety of mobility models to be incorporated into the tool. The MDG module generates positions of transceivers at specified time instants. The GSG module constructs the graph corresponding to the ad hoc network from the mobility data provided by MDG. The OMT module modifies the connectivity of the graph produced by GSG to allow for occlusion effects. With two other modules, namely an activity data generator (ADG) which generates packet transmission activities for transceivers and a packet activity simulator (PAS) which simulates the movement and interaction of packets among the transceivers, the framework allows the modeling and simulation of ad hoc communication networks. The design of the framework allows a user to incorporate various realistic parameters crucial in the simulation. We illustrate the utility of our framework through a comparative study of three mobility models. Two of these are synthetic models (random waypoint and exponentially correlated mobility) proposed in the literature. The third model is based on an urban population mobility modeling tool (TRANSIMS) developed at the Los Alamos National Laboratory. This tool is capable of providing comprehensive information about the demographics, mobility and interactions of members of a large urban population. A comparison of these models is carried out by computing a variety of parameters associated with the graph structures generated by the models. There has recently been interest in the structural properties of graphs that arise in real world systems. We examine two aspects of this for the graphs created by the mobility models: change associated with power control (range of transceivers) and variation in time as transceivers move in space. Part of the work was done while the authors were visiting the Basic and Applied Simulation Sciences Group at the Los Alamos National Laboratory
Stress intensity factors for an arbitrarily oriented crack near a hole in longeron web

Damage-tolerant design of composite components in aerospace structures requires computationally effective stress and failure analysis methods. This study introduces an analytical/numerical method to determine the stress field and the stress intensity factors in a composite longeron web with an arbitrarily oriented straight crack near a hole. Typical of webs in wing longerons with massive belts, the tapered web is loaded in bending and shear. The solution method makes use of the complex potentials in conjunction with the boundary collocation technique. The present results are in close agreement with those obtained by finite element.
A rapid method for the assay of plasma estriol in pregnancy.

A method has been developed for the determination of plasma estriol in the second half of pregnancy. Only 1 ml of plasma per analysis is required and 5 determinations in duplicate can be completed in 5–6 hr. Besides passing the usual tests of precision, sensitivity, reproducibility and specificity, accurate values are attainable because each determination is corrected for methodological losses by the isotope technique. Values at term in 34 normal pregnancies ranged from 9.3 to 56 μg/100 ml with a mean of 27 and a median of 25. In normal pregnancy the estriol levels rise regularly as pregnancy progresses, increasing about 5-fold in the third trimester. A rapid fall off in the early post-partum period (1–2 hr) to values one half those obtained just prior to delivery was observed. Glucose, up to 600 mg/100 ml, does not interfere with the analysis.
Dynamics of laser-initiated reactions on Pt(111)

The dynamics of the 308 nm photochemical reaction between CH3Br and H coadsorbed on Pt(111) are discussed. Photoinduced dissociative electron attachment of adsorbed CH3Br produced energetic methyl radicals which abstracted surface H to give desorbing methane photoproduct. Photoproduct angular and translational energy distributions were derived from time-of-flight spectra to a quadrupole mass spectrometer following pulsed excimer laser irradiation of the surface.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Fundamental frequency onset and offset behavior: a comparative study of children and adults.

Short-term changes in vowel fundamental frequency (F0) immediately preceding (F0 offset) and following (F0 onset) production of voiceless obstruents were examined in groups of 4-year-olds, 8-year-o...
The alleviation of test anxiety by systematic desensitization.

Abstract Twenty-eight test anxious S s were randomly assigned to a relaxation group, a visual imagery group, and a systematic desensitization group in order to determine the relative effectiveness of each treatment in alleviating test anxiety. Following treatment, significant reductions in self-reported anxiety as determined by pre- and post-Test Anxiety Questionnaire (TAQ) scores occurred only for the systematic desensitization group. An analysis of the number of subjects per group showing reductions in TAQ score further supported the hypothesis that self-reported test-anxiety reduction occurs more reliably when both components of systematic desensitization are present. However, when the three groups were compared directly, only the visual imagery group was found to differ significantly from the systematic desensitization group, suggesting that relaxation alone may not be a totally ineffective treatment procedure. Results obtained with a second index of anxiety-reduction, performance on an anagram solution task, were not consistent with the self-report data.