cssi/SciSciGPT-SciSciNet huggingface dataset:
“MAKING IT”: The Components and Process of Resilience Among Urban, African‐American, Single Mothers

In contrast to the bulk of research on urban single mothers that focuses on risk and negative outcomes, this qualitative study of ten resilient mothers living in risky neighborhoods uses the women's own words to conceptualize resilience as an ongoing process of balancing risk and protective factors in eight domains. The findings question current assumptions about the universality of risk and protective factors, and point to new directions for program and policy.
Excess incidence of ALS in young Gulf War veterans

To the Editor: I agree with Dr. Haley,1 that the fundamental question is whether the incidence in the young Gulf War veteran population has exceeded the expected incidence for that age group, based on age-specific incidence in the general population. Comparison2 to age-matched data from a contemporaneous US population with excellent case findings3 shows that was not the case. How did Dr. Haley find otherwise? New, elaborate, and unvalidated methodology was used for the first time in this article to calculate the number of cases to be expected in the deployed 1990 Gulf War cohort.1 In my opinion, an unvalidated method cannot be relied upon to draw conclusions, just as one would not allow an unvalidated cholesterol assay to be used to determine cholesterol levels in patients, and then base treatment decisions on the results. In my opinion, this method introduced two types of systematic errors: (a) errors that resulted in a “low-ball” estimate of the expected …
Recent work on Alzheimer's disease transgenics.

Abstract The most significant feature of the current transgenic models of Alzheimer's disease continues to be the amyloid phenotype. In the past year, mice have been more extensively characterized in terms of the effect of amyloid accumulation on downstream events, such as neurodegeneration and behavioral changes, but the results have been complex. Genetic crosses have shown that apolipoprotein E and TGF-β1 influence the deposition event and that the presenilins act synergistically with the amyloid precursor protein in pathology development. The mice have great utility in amyloid modulation studies but are still not complete models of Alzheimer's disease.
Using interviews to understand the assignment mechanism in a nonexperimental study: the case of eighth grade algebra.

Many inquiries regarding the causal effects of policies or programs are based on research designs where the treatment assignment process is unknown, and thus valid inferences depend on tenuous assu...
Assessment of health status and quality of life outcomes for children with asthma

Increasing interest has been directed to understanding health outcomes associated with pediatric disease processes, including asthma. Salient areas of interest to health outcomes research include the child's and parent's subjective experience with the disease, a concept most often identified as quality of life. Quality of life reports fit within a broader scope of outcome measures embodied in the concept of children's health status. This article provides a description for how a child's health status can be understood theoretically, from a research perspective and in clinical practice. Emphasis is directed to how information obtained from both the child and parent is critical to outcomes research and clinical practice. Unique methodologic problems in assessing child health outcomes such as the challenge of understanding how the child's changing cognitive development may have an impact on responses to outcome measures and the role of contextual variables such as family characteristics are discussed. A variety of subjective and objective outcome measures currently exist that may be used in research on children with asthma. Practical guidelines for implementing outcomes research for children with asthma are presented. Clinical researchers must use multiple outcome measures for assessing asthma characteristics, including psychosocial characteristics, which have an impact on adherence and treatment regimens.
Climate control through ionization

Abstract This paper summarizes some of the experimental evidence of the apparent biological effects produced by atmospheric ionization. Thermionic ion sources are discussed and the results of experimental determinations of their characteristics are presented.
Role of Calcitonin Gene-Related Peptide in Bone Repair after Cyclic Fatigue Loading

Background Calcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been widely studied, and CGRP is currently considered to be an osteoanabolic peptide that has effects on both osteoclasts and osteoblasts. However, relatively little is known about the physiological role of CGRP in-vivo in the skeletal responses to bone loading, particularly fatigue loading. Methodology/Principal Findings We used the rat ulna end-loading model to induce fatigue damage in the ulna unilaterally during cyclic loading. We postulated that CGRP would influence skeletal responses to cyclic fatigue loading. Rats were fatigue loaded and groups of rats were infused systemically with 0.9% saline, CGRP, or the receptor antagonist, CGRP8–37, for a 10 day study period. Ten days after fatigue loading, bone and serum CGRP concentrations, serum tartrate-resistant acid phosphatase 5b (TRAP5b) concentrations, and fatigue-induced skeletal responses were quantified. We found that cyclic fatigue loading led to increased CGRP concentrations in both loaded and contralateral ulnae. Administration of CGRP8–37 was associated with increased targeted remodeling in the fatigue-loaded ulna. Administration of CGRP or CGRP8–37 both increased reparative bone formation over the study period. Plasma concentration of TRAP5b was not significantly influenced by either CGRP or CGRP8–37 administration. Conclusions CGRP signaling modulates targeted remodeling of microdamage and reparative new bone formation after bone fatigue, and may be part of a neuronal signaling pathway which has regulatory effects on load-induced repair responses within the skeleton.
CNVs in Epilepsy.

Copy number variants (CNVs) are deletions or duplications of DNA. CNVs have been increasingly recognized as an important source of both normal genetic variation and pathogenic mutation. Technologies for genome-wide discovery of CNVs facilitate studies of large cohorts of patients and controls to identify CNVs that cause increased risk for disease. Over the past 5 years, studies of patients with epilepsy confirm that both recurrent and non-recurrent CNVs are an important source of mutation for patients with various forms of epilepsy. Here, we will review the latest findings and explore the clinical implications.
Structure of health-related quality of life among people with and without functional limitations

Purpose The objective of this study was to assess the factor structure of nine health-related quality of life (HRQOL) survey items among people with and without disabilities or functional limitations (FL) and determine whether factor loadings were similar for the two groups.
CQ Interview: Margaret Battin, Howard Brody, Patricia Marshall, and Robyn Shapiro on Physician-Aided Death

In The Netherlands, the close relationship between doctor and patient over time can be viewed as an advantage in protecting the patient. Is it possible to implement this aspect of euthanasia in the United States?
Effects of Andreev scattering on the tunneling conductance in superconducting MgB2

Abstract The discovery of superconductivity in MgB 2 with a rather high transition temperature of T =39 K has opened up new territory. Recently, single crystals of MgB 2 have become available. Based on the available experimental data an anisotropic s-wave superconducting order parameter has been proposed to model the properties of this material. In this contribution, we discuss the effects of Andreev scattering on the tunneling conductance between a normal metal point contact and a sample of superconducting MgB 2 within the theoretical framework of Blonder, Tinkham, and Klapwijk (BTK). The issue is to distinguish the response of a multi-gap isotropic s-wave model, suggested for MgB 2 by other members of the community, from the single-gap anisotropic s-wave order parameter we are proposing. We can show that for intermediate values of the tunneling matrix element between the normal metal tip and the superconducting sample a two-peak tunneling conductance is obtained, resembling recent measurements by Szabo et al., Phys. Rev. Lett. 87, (2001) 137005. Furthermore, in the Giaever tunneling limit only one sharp cusp should be observable at the frequency of the maximum of the superconducting gap.
Wavefront coherence area for predicting visual acuity of post-PRK and post-PARK refractive surgery patients

Many current corneal topography instruments (called videokeratographs) provide an `acuity index' based on corneal smoothness to analyze expected visual acuity. However, post-refractive surgery patients often exhibit better acuity than is predicted by such indices. One reason for this is that visual acuity may not necessarily be determined by overall corneal smoothness but rather by having some part of the cornea able to focus light coherently onto the fovea. We present a new method of representing visual acuity by measuring the wavefront aberration, using principles from both ray and wave optics. For each point P on the cornea, we measure the size of the associated coherence area whose optical path length (OPL), from a reference plane to P's focus, is within a certain tolerance of the OPL for P. We measured the topographies and vision of 62 eyes of patients who had undergone the corneal refractive surgery procedures of photorefractive keratectomy (PRK) and photorefractive astigmatic keratectomy (PARK). In addition to high contrast visual acuity, our vision tests included low contrast and low luminance to test the contribution of the PRK transition zone. We found our metric for visual acuity to be better than all other metrics at predicting the acuity of low contrast and low luminance. However, high contrast visual acuity was poorly predicted by all of the indices we studied, including our own. The indices provided by current videokeratographs sometimes fail for corneas whose shape differs from simple ellipsoidal models. This is the case with post-PRK and post-PARK refractive surgery patients. Our alternative representation that displays the coherence area of the wavefront has considerable advantages, and promises to be a better predictor of low contrast and low luminance visual acuity than current shape measures.
Chromatin: A Tail of Repression

Summary Genetic evidence on the role of specific histone amino acids or their posttranslational modifications in metazoan development has been lacking. A recent study reports that fruit flies carrying histone H3 lysine 27 (H3K27) mutations have the same homeotic gene expression and developmental defects as mutations in the enzyme that trimethylates H3K27.
Archival Reference: State of the Art.

The decade that has passed since the last time The Reference Librarian looked at archival reference has seen many changes for the archival profession. While the techniques and procedures of reference service have not changed dramatically, a certain level of standardization has been reached. Access and outreach remain their traditional ties to reference; as archivists have become less willing to accept access restrictions, recent copyright decisions have tended towards limiting the use of archival material. Research in reference, in users and in use has increased, although not as much as some would prefer; it has also been affected by debate over the archival mission. The increasing pace of automation has provided new delivery mechanisms and opportunities for access and outreach while at the same time it has called into question some of the basic tenets of the archival profession. New approaches have been proposed for reference in the digital environment.
Identification of lactate dehydrogenase-M polypeptide translated in vitro from human and mouse tumor cell poly(A)-containing messenger RNA.

Abstract 1. 1. Rabbit anti-human lactate dehydrogenase-5(M4) antisera were raised which cross-reacted with mouse lactate dehydrogenase M polypeptide. The antisera were used for identification of human and mouse LDH-M polypeptides synthesized using an in vitro system directed by the mRNAs. 2. 2. The in vitro translation products directed by both mRNAs were similar in size and immunologically identical to the authentic LDH-M polypeptides. 3. 3. The sizes of the mRNAs encoding for both human and mouse LDH-M polypeptides were similar, about 15S(1445 nucleotides) and were shorter than the corresponding rat mRNA which is about 18S(1765 nucleotides).
A FORTRAN II program for conducting sequence distribution calculations

A FORTRAN II program for calculating copolymer compositions, run numbers, diad, triad, tetrad, and pentad distributions, and sequence number distributions and sequence weight distributions for addition type copolymers is described. The program is applicable to both instantaneous and high-conversion copolymers.
Paretic muscle atrophy and non-contractile tissue content in individual muscles of the post-stroke lower extremity

Muscle atrophy is one of many factors contributing to post-stroke hemiparetic weakness. Since muscle force is a function of muscle size, the amount of muscle atrophy an individual muscle undergoes has implications for its overall force-generating capability post-stroke. In this study, post-stroke atrophy was determined bilaterally in fifteen leg muscles with volumes quantified using magnetic resonance imaging (MRI). All muscle volumes were adjusted to exclude non-contractile tissue content, and muscle atrophy was quantified by comparing the volumes between paretic and non-paretic sides. Non-contractile tissue or intramuscular fat was calculated by determining the amount of tissue excluded from the muscle volume measurement. With the exception of the gracilis, all individual paretic muscles examined had smaller volumes in the non-paretic side. The average decrease in volume for these paretic muscles was 23%. The gracilis volume, on the other hand, was approximately 11% larger on the paretic side. The amount of non-contractile tissue was higher in all paretic muscles except the gracilis, where no difference was observed between sides. To compensate for paretic plantar flexor weakness, one idea might be that use of the paretic gracilis actually causes the muscle to increase in size and not develop intramuscular fat. By eliminating non-contractile tissue from our volume calculations, we have presented volume data that more appropriately represents force-generating muscle tissue. Non-uniform muscle atrophy was observed across muscles and may provide important clues when assessing the effect of muscle atrophy on post-stroke gait.
Catalyst structural effects in titanocene-catalyzed pinacol coupling: activity, stereoselectivity and mechanistic implications

Abstract The effects of catalyst structural variation on the activity and selectivity of titanocene-catalyzed pinacol coupling of cyclohexane carboxaldehyde by Mn/TMSCl have been evaluated. Complexes which have been tested include: Cp 2 TiCl 2 ( 1 ), Cp 2 TiBr 2 ( 2 ), (C 5 Me 5 ) 2 TiCl 2 ( 3 ), (1,3- t -Bu 2 C 5 H 3 ) 2 TiCl 2 ( 4 ), (1,3- t -Bu 2 C 5 H 3 )(Cp)TiCl 2 ( 5 ), ansa -[(η 5 -tetrahydroindenyl)CH 2 CH 2 (η 5 -tetrahydroindenyl)]TiCl 2 ( 6 ), and ansa -[(η 5 -Cp)CH 2 CH 2 (η 5 -fluorenyl)]TiCl 2 ( 7 ). Cp 2 TiCl 2 ( 1 ) is the most active (pre)catalyst for pinacol silylether ( 8a ) formation, but Brintzinger's complex 6 provides the best dl /meso diastereoselectivity (5:1). Complexes 2 , 4 and 7 slowly catalyze the predominant formation of the corresponding pinacol acetal 9a as a secondary product. Comparative stoichiometric reactions of benzaldehyde/Me 3 SiCl with [Cp 2 TiCl·MnCl 2 (THF) 2 ·Cp 2 TiCl] ( 10 ) and [Cp 2 TiCl] 2 ( 11 ) result in highly diastereoselective pinacol silylether formation with binuclear 11 (29:1), but primarily the production of pinacol acetal ( 9b ) from trimetallic 10 , suggesting a dominant role for the binuclear complex (or derived mononuclear species) in the catalytic systems employing Cp 2 TiCl 2 /M/TMSCl, contrary to previous suggestions.
Frontal Circulations in the Presence of Small Moist Symmetric Stability

Abstract Observations in saturated frontal regions occasionally show that the flow has become neutral to reversible slantwise displacements along pseudo-angular momentum surfaces so that the effective potential vorticity is nearly zero for further saturated displacements. A strong response to frontogenesis is indicated in these regions, as suggested by the parabolic nature of the Sawyer–Eliassen equation when the potential vorticity vanishes. Using idealized distributions of temperature and geostrophic deformation, we derive solutions of the aforementioned equation for the cross-front circulation in the case where the potential vorticity is vanishingly small for upward displacements but moderate for downward displacements. While the solutions are self-consistent, it is not known whether they are unique. They show that a strong concentrated sloping updraft occurs somewhat to the warm side of the region of maximum geostrophic compression of the isotherms. This circulation closely resembles the flow in a mes...
One-step growth curve of Western equine encephalomyelitis virus on chicken embryo cells grown in vitro and analysis of virus yields from single cells.

The rate of adsorption of WEE virus onto chicken embryo cells in vitro was determined both on a cell layer and on a cell suspension. One-step growth curves were determined in cell suspensions and on cell layers. The latent period varied between 2 and 3frac12 hours; it was shorter on cell layers and decreased with higher multiplicity of infection. The shortest period is probably the real latent period. The growth curves of the virus showed an initial exponential rise and reached a maximal constant value after 6 to 8 hours. The maximum virus yield per cell varied between 200 and 1000 on the cell layer, and between 100 and 200 in suspended cells. The yield of single infected cells was determined. An analysis of the distributions of the individual yields obtained after various periods of virus growth led to two main conclusions: (1) that virus is released from the same cell over a long period of time; (2) that one phase of the intracellular virus growth is exponential.
The stability of Si1−xGex strained layers on small-area trench-isolated silicon

The combined effects of isolation stress, active area size, and SiGe misfit strain on dislocation generation in an advanced SiGe heterojunction bipolar transistor (HBT) process were studied. Eight-inch wafers were patterned with polysilicon-filled deep, and oxide-filled shallow trench isolation similar to that used in IBM’s analog SiGe HBT technology. Half of the wafers were subjected to an additional stress-producing oxidation prior to SiGe growth. Si1−xGex films containing 0, 5.5, 9, and 13 at.% Ge were grown epitaxially by ultrahigh vacuum chemical vapor deposition (UHV CVD). The films were of constant thickness with an intrinsic Si cap. Some samples received an additional relaxation anneal following deposition. After the growth and anneal cycles, the dislocation density was determined by transmission electron microscopy (TEM). On nonstressed samples, no dislocations were observed in the device areas, even at Ge concentrations which are not stable to misfit dislocation generation in blanket form. This small area effect has been observed on patterned substrates that do not have functional device isolation. On the stressed-isolation wafers, the compressive stress from the oxidation of the trench sidewalls was found to intensify stress in the SiGe films, and to lower the critical strain at which misfit dislocations appeared. In large active areas on these wafers, two distinct dislocation regions were observed. Defects at the edge resembled those caused by isolation stress, while the defects in the center were more typical of the misfit dislocations associated with lattice-mismatch epitaxial films. It is clear that isolation stress must be minimized when fabricating integrated circuits using SiGe epitaxial films. It is also evident that SiGe films grown on nonstressed isolation exhibit the same increase in critical thickness with decreasing lateral dimension that has been observed on much simpler patterned substrates.
Development of a Valid and Reliable Knee Articular Cartilage Condition-Specific Study Methodological Quality Score.

Background:Condition-specific questionnaires are important components in evaluation of outcomes of surgical interventions. No condition-specific study methodological quality questionnaire exists fo...
Corporate Goal Structures and Business Students: A Comparative Study of Values

Are the values of business students of today synchronized with the reality of the present business environment? Two hundred twenty-two business students rated the importance of twenty corporate goals. Moreover, the students rated the same goals as they perceived chief executive officers (CEOs) would have rated them. Significant differences were found between the two ratings, with students ranking social and employee-oriented goals as more important than they perceived CEOs would have.
Two-Zone SMB Process for Binary Separation

Two-zone simulated moving bed (SMB) systems with a storage tank were developed for binary separation. Simulations were done with Aspen Chromatography for the linear dextran T6−raffinose mixture and the nonlinear binaphthol enantiomers mixture. The results for these linear isotherms show that two-zone SMBs give purities comparable to those obtained for a four-zone SMB with the same productivity and desorbent-to-feed ratio (D/F). At D/F = 2.794, the purities obtained in a two-zone decoupled SMB for dextran T6 and raffinose are 94.5% and 97.6%, respectively, whereas in a two-zone coupled SMB, the purities are 95.0% and 97.5%, respectively, compared to a four-zone SMB's purities of 96.1% and 96.6%, respectively. The results for the nonlinear isotherms show that these two-zone SMB systems can obtain good separation but with more desorbent than required for a four-zone SMB. Simulations for two-zone SMBs with one column per zone show that partial feed can improve the product purities and recoveries considerably,...
SYNTHETIC APERTURE RADAR PERFORMANCE IN DETECTiNG SHALLOW BURIED TARGETS

A radar performance model is developed to analyze the capability of wide-band, high- resolution airborne synthetic aperture radar detection of shallow buried targets such as metallic M-20 mines and utility cables. Feasible target detection depths are estimated as functions of radar polarization, depression angle, and frequency in UHF and VHF bands. The performance model has incorporated wave propagation loss, due to wave attenuation inside the soil medium, wave reflection, and divergence at the air-ground interface, radar target cross section estimation via method of moments, radar interference, including both ambient man-made noise and empirical backscattered ground surface clutter, which is determined from existing clutter measurements for bare soil, rocks, and desert terrain.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Detecting Network Attacks in the Internet via Statistical Network Traffic Normality Prediction

The information technology advances that provide new capabilities to the network users and providers, also provide powerful new tools for network intruders that intend to launch attacks on critical information resources. In this paper we present a novel network attack diagnostic methodology, based on the characterization of the dynamic statistical properties of normal network traffic. The ability to detect network anomalies and attacks as unacceptable when significant deviations from the expected behavior occurs. Specifically, to provide an accurate identification of the normal network traffic behavior, we first develop an anomaly-tolerant nonstationary traffic prediction technique that is capable of removing both single pulse and continuous anomalies. Furthermore, we introduce and design dynamic thresholds, where we define adaptive anomaly violation conditions as a combined function of both magnitude and duration of the traffic deviations. Finally numerical results are presented that demonstrate the operational effectiveness and efficiency of the proposed approach under the presence of different attacks, such as mail-bombing attacks and UDP flooding attacks.
Dissociations among daytime sleepiness, nighttime sleep, and cognitive status in Parkinson's disease.

Abstract Background Daytime and nighttime sleep disturbances and cognitive impairment occur frequently in Parkinson's disease (PD), but little is known about the interdependence of these non-motor complications. Thus, we examined the relationships among excessive daytime sleepiness, nighttime sleep quality and cognitive impairment in PD, including severity and specific cognitive deficits. Methods Ninety-three PD patients underwent clinical and neuropsychological evaluations including the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Patients were classified as having normal cognition (PD-NC), mild cognitive impairment (PD-MCI), or dementia (PDD) using recently proposed Movement Disorder Society PD-MCI and PDD criteria. Relationships between the sleep and cognitive measures and PD cognitive groups were examined. Results The PD cohort included PD-NC ( n = 28), PD-MCI ( n = 40), and PDD ( n = 25) patients. ESS scores, as a measure of daytime sleepiness, were significantly worse ( p = 0.005) in cognitively impaired PD patients, particularly PDD patients. ESS scores correlated significantly with Mini-Mental State Examination scores and also with cognitive domain scores for attention/working memory, executive function, memory, and visuospatial function. In contrast, PSQI scores, as a measure of nighttime sleep quality, neither differed among cognitive groups nor correlated with any cognitive measures. Conclusions Daytime sleepiness in PD, but not nighttime sleep problems, is associated with cognitive impairment in PD, especially in the setting of dementia, and attention/working memory, executive function, memory, and visuospatial deficits. The presence of nighttime sleep problems is pervasive across the PD cognitive spectrum, from normal cognition to dementia, and is not independently associated with cognitive impairment or deficits in cognitive domains.
Optical properties of LiI single crystals

The experimental results are reported for a preliminary investigation at liquid nitrogen temperature of the optical transmission, excitation, and emission spectra of pure LiI single crystals in the range from 190 nm (6.53 eV) to 500 nm (2.48 eV). Five emission bands have been found with peak positions at 291 nm (4.26 eV), 361 nm (3.44 eV), 376 nm (3.30 eV) 406 nm (3.05 eV), and 412 nm (3.01 eV). The corresponding excitation spectrum for each luminescence is reported, the excitation spectrum for the 376 nm emission peaks at 208 nm (5.96 eV) agreeing very closely to the position of the exciton peak as found for thin film absorption measurements. The 291 nm band is believed to be due to an impurity center. The 406 nm emission is indicative of a LiI crystal whose surface has become contaminated by exposure to water vapor. The emission centered at 361 nm has the same excitation spectrum as the 412 nm band. Quenching the crystal from 220 °C into liquid nitrogen causes these dual bands to be enhanced and introduces a new peak in their excitation spectra at the low-energy side of the exciton. These emission bands are believed to be associated with a defect center. Experimentelle Resultate einer vorlaufigen Untersuchung von optischen Absorptions-, Anregungs- und Emissionsspektren an reinen LiJ-Einkristallen bei der Temperatur von flussigem Stickstoff werden mitgeteilt. Die Messungen wurden im Bereich 190 nm (6,53 eV) bis 500 nm (2,48 eV) durchgefuhrt. Funf Emissionsbanden wurden gefunden, deren Maxima bei 291 nm (4,26 eV), 361 nm (3,44 eV), 376 nm (3,30 eV), 406 nm (3,05 eV) und 412 nm (3,01 eV) liegen. Fur jede dieser Lumineszenzen wird das entsprechende Anregungsspektrum angegeben. Das Maximum der 376 nm-Anregungsbande liegt bei 208 nm (5,96 eV), in guter Ubereinstimmung mit der Wellenlange, die fur das Maximum des Exzitonen-Absorptionsspektrums an dunnen Schichten gefunden worden ist. Es wird angenommen, das die 291 nm-Bande von einem Verunreinigungszentrum stammt. Die Emission bei 406 nm ist typisch fur einen LiJ-Kristall, dessen Oberflache durch Kontakt mit Wasserdampf verunreinigt worden ist. Die bei 361 nm liegende Emission besitzt das gleiche Anregungsspektrum wie die 412 nm-Bande. Abschreckung des Kristalls von 220 °C auf die Temperatur des flussigen Stickstoffs last diese beiden Bander starker hervortreten und hat das Erscheinen eines neuen Maximums in deren Anregungsspektren zur Folge, das, vom Exziton aus gesehen, auf der Seite niedriger Energie liegt. Diese Emissionsbanden werden einem Defektzentrum zugeschrieben.
Update on Treatment of Liver Metastases: Focus on Ablation Therapies

There is substantial and growing interest in the use of local therapies to treat patients with metastatic cancer, especially those deemed to have "oligometastatic" disease. Much of the literature to date consists of reports on metastasectomy for liver and lung metastases. Non-surgical minimally or non-invasive treatments including thermal ablation, irreversible electroporation, and high-dose radiation therapy (stereotactic ablative radiation therapy) can also be used in the treatment of primary and secondary tumors, including in the treatment of liver metastases. In this review, we discuss the rationale for using these ablative treatments in the treatment of liver metastases including similarities and differences between them.
Memories Slipping Away: The Tenth Anniversary of 9/11.

Historical memories are often weak, and must be kept alive by media, schools, and government. The disaster of 9/11 is one of those unusual and unsettling events that call for recognition. But memor...
Insights into the molecular recognition of the 5'-GNN-3' family of DNA sequences by zinc finger domains.

Abstract In order to construct zinc finger domains that recognize all of the possible 64 DNA triplets, it is necessary to understand the mechanisms of protein/DNA interactions on the molecular level. Previously we reported 16 zinc finger domains which had been characterized in detail to bind specifically to the 5′-GNN-3′ family of DNA sequences. Artificial transcription factors constructed from these domains can regulate the expression of endogenous genes. These domains were created by phage-display selection followed by site-directed mutagenesis. A total of 84 mutants of a three-domain zinc finger protein have been analyzed for their DNA-binding specificity. Here, we report the results of this systematic and extensive mutagenesis study. New insights into zinc finger/DNA interactions were obtained by combining specificity data with computer modeling and comparison with known structural data from NMR and crystallographic studies. This analysis suggests that unusual cross-strand and inter-helical contacts are made by some of these proteins, and the general orientation of the recognition helix to the DNA is flexible, even when constrained by flanking zinc finger domains. These findings disfavor the utility of existing simple recognition codes and suggest that highly specific domains cannot be obtained from phage display alone in most cases, but only in combination with rational design. The molecular basis of zinc finger/DNA interaction is complex and its understanding is dependent on the analysis of a large number of proteins. This understanding should enable us to refine rapidly the specificity of other zinc finger domains, as well as polydactyl proteins constructed with these domains to recognize extended DNA sequences.
147Sm-143Nd systematics of Earth are inconsistent with a superchondritic Sm/Nd ratio

The relationship between the compositions of the Earth and chondritic meteorites is at the center of many important debates. A basic assumption in most models for the Earth’s composition is that the refractory elements are present in chondritic proportions relative to each other. This assumption is now challenged by recent 142 Nd/ 144 Nd ratio studies suggesting that the bulk silicate Earth (BSE) might have an Sm/Nd ratio 6% higher than chondrites (i.e., the BSE is superchondritic). This has led to the proposal that the present-day 143 Nd/ 144 Nd ratio of BSE is similar to that of some deep mantle plumes rather than chondrites. Our reexamination of the long-lived 147 Sm- 143 Nd isotope systematics of the depleted mantle and the continental crust shows that the BSE, reconstructed using the depleted mantle and continental crust, has 143 Nd/ 144 Nd and Sm/Nd ratios close to chondritic values. The small difference in the ratio of 142 Nd/ 144 Nd between ordinary chondrites and the Earth must be due to a process different from mantle-crust differentiation, such as incomplete mixing of distinct nucleosynthetic components in the solar nebula.
Polymer chain length effects on fibroblast attachment on nylon-3-modified surfaces.

Nylon-3 polymers have a polyamide backbone reminiscent of that found in proteins (β- vs α-amino acid residues, respectively), which makes these materials interesting for biological applications. Because of the versatility of the ring-opening polymerization process and the variety of β-lactam starting materials available, the structure of nylon-3 copolymers is highly amenable to alteration. A previous study showed that relatively subtle changes in the structure or ratio of hydrophobic and cationic subunits that comprise these polymers can result in significant changes in the ability of nylon-3-bearing surfaces to support cell adhesion and spreading. In the present study, we have exploited the highly tailorable nature of these polymers to synthesize new versions possessing a wide range of chain lengths, with the intent of optimizing these materials for use as cell-supportive substrates. We find that longer nylon-3 chains lead to better fibroblast attachment on modified surfaces and that at the optimal chain...
Inconsistency between peri-saccadic mislocalization and compression: evidence for separate "what" and "where" visual systems.

The view of two separate “what” and “where” visual systems is supported by compelling neurophysiological evidence. However, very little direct psychophysical evidence has been presented to suggest that the two functions can be separated in neurologically intact persons. Using a peri-saccadic perception paradigm in which bars of different lengths were flashed around saccade onset, we directly measured the perceived object size (a “what” attribute) and location (a “where” attribute). We found that the perceived object location shifted towards the saccade target to show strongly compressed localization, whereas the perceived object size was not compressed accordingly. This dissociation indicates that the perceived size is not determined by spatial localization of the object boundary, providing direct psychophysical evidence to support that “what” and “where” attributes of objects are indeed processed separately.
Immunodeficiency models in characterization of immune responses to parasites - An overview

Abstract The use of selected immunosuppressant agents and genetically immunodeficient animals in studies designed to characterize the immune response to parasitic infections is reviewed. Immunosuppression induced by commonly used chemicals (corticosteroids and alkylating agents) and ionizing radiation is examined briefly. A greater emphasis is placed on congenitally immunodeficient animals and on immunosuppression induced by purified antisera directed against a variety of cellular specificities. The use of such immunodeficient animals has aided our understanding of the complex interrelationship between host and parasite. However, chemical immunosuppressants and the levels of irradiation used in adoptive cell transfer studies are usually indiscriminant in their toxic effects on a variety of tissues other than those targeted. These affected tissues may be crucial in establishment of the delicate physiological balance required for maintenance of equilibrium between host and parasite. Thus the effects of cytotoxic drugs or irradiation on parasite burdens may reflect alteration of not only immunity, but other essential factors leading to misinterpretation of results. Use of congenitally immunodeficient animals, which are readily repaired by introduction of specific cellular components, may be more useful in dissecting host responses to parasites. In addition, depletion of specific components of the immune system through use of anti-isotype antiserum, for example, is another useful probe. These approaches do not suffer from the generalized cytotoxic effects of chemicals and irradiation, and remove a potentially important and misleading variable from experimental designs. They also allow one to discriminate between non-specific inflammatory and specific immunological factors. The potential pitfalls of broadly used induced immunodeficiency states in studies on parasitisms may now be overcome at least partially by use of highly purified and specific cytotoxic reagents coupled with an ever-increasing array of genetically immunodeficient animal models.
Comparison of Permacol™ and Strattice™ for the repair of abdominal wall defects

Incisional hernias repaired with mesh can be expected have a lower recurrence rate than with primary repair. Biologic implants have replaced synthetic meshes in certain complex settings. We compared two porcine-dermis derived implants—cross-linked Permacol™ biologic implant and non-cross linked Strattice-firm™ tissue matrix—in a ventral hernia animal model. Our hypothesis is that cross-linked biologic implants are remodeled differently and thus behave differently than non-cross-linked biologic implants. Eighty-nine, female Sprague-Dawley rats had a 3 × 3 cm full-thickness segment of the abdominal wall excised. A 3 × 3 cm biologic mesh, either Permacol™ or Strattice™, was secured and the skin was closed. At 1-, 3-, 6- and 12-month time intervals, rats in each group were sacrificed and the mesh was excised. The number of adhesions, surface area, mesh thickness and tensile strength were determined, and immunohistochemical analysis performed. Permacol™ biologic implant maintained thickness while Strattice™ thickness decreased significantly starting at 3 months. Adhesion area and tenacity were not significantly different between Permacol™ and Strattice™ at all time points. The tensile strength of the Permacol™ biologic implant was greater than that of Strattice™ at 3, 6 and 12 months. Migration of host cells and neo-vascularization was observed in both implant groups. Cross-linked materials may prove more durable in the remodeling process as suggested by the increased thinning and weakening observed in non-cross-linked biomesh.
High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability.

Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, ∼2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed ne...
The aging of electrical insulation at cryogenic temperatures

The author points out that the application of superconductive conductors requires the development of electrical insulation capable of operating for many years at temperatures as low as 4 K and ranging to approximately 100 K for the most recent superconductors. The insulation is subjected to stresses caused by the cryogenic environment, possibly high pressures and radiation, in addition to the electrical stresses associated with service. Experimental results of aging tests for small samples are reported, and operating experiences with superconducting devices in service for about a decade are discussed. >
Preapoptotic phenotype of viral epitope-specific CD8 T cells precludes memory development and is an intrinsic property of the epitope

Virus-specific CD8 T cells after clearance of infection reduce their number in lymphoid organs by apoptotic death and by migration into peripheral tissues. During and after infection, many lymphocytic choriomeningitis virus (LCMV)-specific CD8 T cells in lymphoid but not peripheral tissues are in a preapoptotic state, as detected by the early apoptosis marker annexin V. In this report, we investigated the significance of this preapoptotic state and how it may be influenced by viral epitope specificity. Stimulation with anti-CD3 or IL-2 in vitro postponed DNA fragmentation in annexin V + cells, but adoptive transfer studies in vivo showed that this preapoptotic phenotype precluded the development of functional memory. CD8 T cells specific to LCMV epitopes NP396 and gp33 differed in their preapoptotic state, with NP396-specific T cells binding more annexin V than gp33-specific T cells. These epitope- and tissue-dependent differences were seen in primary, memory, and secondary responses and in mice receiving different displays of Ag by infection with LCMV strains of different tropisms or by infection with vaccinia virus recombinants expressing LCMV proteins. Thus, the epitope-dependent differences in apoptosis were independent of virus tropisms, duration of Ag exposure, and competition within APCs, and were an intrinsic property of the epitope. The tissue-dependent and epitope-dependent preapoptotic state correlated with reduced expression of IL-7Rα.
Constraints on upper mantle viscosity from the flow‐induced pressure gradient across the Australian continental keel

[1] The thickness of continental lithosphere varies considerably from tectonically active to cratonic regions, where it can be as thick as 250–300 km. Embedded in the upper mantle like a ship, when driven to move by a velocity imposed at the surface, a continental keel is expected to induce a pressure gradient in the mantle. We hypothesize that the viscosity of the asthenosphere or the shear coupling between lower lithosphere and asthenosphere should control this pressure effect and thus the resulting dynamic topography. We perform three-dimensional finite element calculations to examine the effects of forcing a continental keel by an imposed surface velocity, with the Australian region as a case study. When the upper mantle is strong but still weaker than the lower mantle, positive dynamic topography is created around the leading edge, and negative dynamic topography is created around the trailing edge of the keel, which is measurable by positive and negative geoid anomalies, respectively. For a weak upper mantle the effect is much reduced. We analyze geoidal and gravity anomalies in the Australian region by spatiospectral localization using Slepian functions. The method allows us to remove a best fit estimate of the geographically localized low spherical harmonic degree contributions. Regional geoid anomalies thus filtered are on the order of ±10 m across the Australian continent, with a spatial pattern similar to that predicted by the models. The comparison of modeled and observed geoid anomalies places constraints on mantle viscosity structure. Models with a two-layer mantle cannot sufficiently constrain the ratio of viscosity between the upper and lower mantle. The addition of a third, weak, upper mantle layer, an asthenosphere, amplifies the effects of keels. Our three-layer models, with lower mantle viscosity of 3 × 1022 Pa s, suggest that the upper mantle (asthenosphere) is 300 times weaker than the lower mantle, while the transition zone (400–670 km depths) has a viscosity varying between 1021 and 1022 Pa s.
Inhibition of Human CD4+CD25+high Regulatory T Cell Function

CD4(+)CD25(+high) T cells are potent regulators of autoreactive T cells. However, it is unclear how regulatory CD4(+)CD25(+high) cells discriminate between desirable inflammatory immune responses to microbial Ags and potentially pathologic responses by autoreactive T cells. In this study, an in vitro model was created that allowed differential activation of regulatory CD4(+)CD25(+high) and responder CD4(+) T cells. If CD4(+)CD25(+high) regulatory cells were strongly activated, they maintained suppressive effector function for only 15 h, while stimulation with weaker TCR stimuli produced regulatory cells that were suppressive until 60 h after activation. In contrast, strongly activated CD4(+) responder T cells were resistant to regulation at all time points, while weakly stimulated CD4(+) cells were sensitive to suppression until 38 or 60 h after activation depending upon the strength of the stimulus. The extent of suppression mediated by CD4(+)CD25(+high) cells also depended on the strength of stimulation in an Ag-specific system. Thus, the stronger the TCR signal, the more rapidly and more completely the responder cells become refractory to suppression.
Stromal microenvironment processes unveiled by biological component analysis of gene expression in xenograft tumor models

Background Mouse xenograft models, in which human cancer cells are implanted in immune-suppressed mice, have been popular for studying the mechanisms of novel therapeutic targets, tumor progression and metastasis. We hypothesized that we could exploit the interspecies genetic differences in these experiments. Our purpose is to elucidate stromal microenvironment signals from probes on human arrays unintentionally cross-hybridizing with mouse homologous genes in xenograft tumor models.
Constructing a continuous phase time history from TDMA signals for opportunistic navigation

A technique is developed for reconstructing a continuous phase time history from the noncontinuous phase bursts of time division multiple access (TDMA) signals. A continuous phase time history facilitates exploitation of TDMA signals as signals of opportunity (SOPs) within an opportunistic navigation framework. Because of their widespread use and availability in today's wireless communication market, TDMA signals are attractive candidate SOPs for opportunistic navigation. The phase reconstruction technique presented here combines an integer least squares technique for estimating phase ambiguities at the beginning of each TDMA phase burst with a Kalman filter and smoother for removing these ambiguities and optimally “stitching” the bursts together. A Monte-Carlo-type simulation and test environment has been developed to investigate the sensitivity of the proposed phase reconstruction technique to various system parameters, namely, carrier-to-noise ratio, receiver clock quality, TDMA transmitter clock quality, line-of-sight acceleration uncertainty, and TDMA burst structure. Simulation results indicate that successful carrier phase reconstruction is most strongly dependent on the TDMA burst period and on the combined phase random walk effect of the receiver and transmitter clocks, the propagation effects, and the range errors.