cssi/SciSciGPT-SciSciNet huggingface dataset:
Applying species-tree analyses to deep phylogenetic histories: Challenges and potential suggested from a survey of empirical phylogenetic studies

Coalescent-based methods for species-tree estimation are becoming a dominant approach for reconstructing species histories from multi-locus data, with most of the studies examining these methodologies focused on recently diverged species. However, deeper phylogenies, such as the datasets that comprise many Tree of Life (ToL) studies, also exhibit gene-tree discordance. This discord may also arise from the stochastic sorting of gene lineages during the speciation process (i.e., reflecting the random coalescence of gene lineages in ancestral populations). It remains unknown whether guidelines regarding methodologies and numbers of loci established by simulation studies at shallow tree depths translate into accurate species relationships for deeper phylogenetic histories. We address this knowledge gap and specifically identify the challenges and limitations of species-tree methods that account for coalescent variance for deeper phylogenies. Using simulated data with characteristics informed by empirical studies, we evaluate both the accuracy of estimated species trees and the characteristics associated with recalcitrant nodes, with a specific focus on whether coalescent variance is generally responsible for the lack of resolution. By determining the proportion of coalescent genealogies that support a particular node, we demonstrate that (1) species-tree methods account for coalescent variance at deep nodes and (2) mutational variance – not gene-tree discord arising from the coalescent – posed the primary challenge for accurate reconstruction across the tree. For example, many nodes were accurately resolved despite predicted discord from the random coalescence of gene lineages and nodes with poor support were distributed across a range of depths (i.e., they were not restricted to a particular recent divergences). Given their broad taxonomic scope and large sampling of taxa, deep level phylogenies pose several potential methodological complications including difficulties with MCMC convergence and estimation of requisite population genetic parameters for coalescent-based approaches. Despite these difficulties, the findings generally support the utility of species-tree analyses for the estimation of species relationships throughout the ToL. We discuss strategies for successful application of species-tree approaches to deep phylogenies.
DDMA-charts: Nonparametric multivariate moving average control charts based on data depth

This paper studies the DDMA–chart, a data depth based moving–average control chart for monitoring multivariate data. This chart is nonparametric and it can detect simultaneously location and scale changes in the process. It improves upon the existing r– and Q–chart in the efficiency of detecting location changes. Both theoretical justifications and simulation studies are provided. Comparisons with some existing multivariate control charts via simulation results are also provided. Some applications of the DDMA–chart to the analysis of airline performance data (collected by the FAA) are demonstrated. The results indicate that the DDMA–chart is an effective nonparametric multivariate control chart.
Preferential mammary storage and secretion of immunoglobulin gamma (IgG) subclasses in swine.

Abstract Levels of three immunoglobulin gamma (IgG) subclasses, IgGA, IgGB and IgGC, were measured in sow sera, mammary glands, colostrum and milk samples by the single radial immunodiffusion. Serum IgGA and IgGB levels, but not IgGC, showed time dependent variations during gestation and lactation periods. The IgGA level started to decline at day 106 of gestation, reached its minimum at farrowing, and returned to the pre-gestation level 1–3 weeks after weaning. The serum IgGB level started to decrease at day 111 of gestation, reached its minimum at farrowing, and returned to the initial gestation level 1 week after farrowing. A notable decrease (P
The Quaker petition of 1790: A challenge to democracy in early America

(1985). The Quaker petition of 1790: A challenge to democracy in early America. Slavery & Abolition: Vol. 6, No. 2, pp. 151-159.
Gamma Ray Line Constraints on Effective Theories of Dark Matter

A monochromatic gamma ray line results when dark matter particles in the galactic halo annihilate to produce a two body final state which includes a photon. Such a signal is very distinctive from astrophysical backgrounds, and thus represents an incisive probe of theories of dark matter. We compare the recent null results of searches for gamma ray lines in the galactic center and other regions of the sky with the predictions of effective theories describing the interactions of dark matter particles with the Standard Model. We find that the null results of these searches provide constraints on the nature of dark matter interactions with ordinary matter which are complementary to constraints from other observables, and stronger than collider constraints in some cases.
Breast cancer spatial heterogeneity in near-infrared spectra and the prediction of neoadjuvant chemotherapy response

We describe an algorithm to calculate an index that characterizes spatial differences in broadband near-infrared ((NIR), 650-1000 nm) absorption spectra of tumor-containing breast tissue. Patient-specific tumor spatial heterogeneities are visualized through a heterogeneity spectrum function (HS). HS is a biomarker that can be attributed to different molecular distributions within the tumor. To classify lesion heterogeneities, we built a heterogeneity index (HI) derived from the HS by weighing the HS in specific NIR absorption bands. It is shown that neoadjuvant chemotherapy (NAC) response is potentially related to the tumor heterogeneity. Therefore, we corre- late the heterogeneity index obtained prior to treatment with the final response to NAC. From a pilot study of 15 can- cer patients treated with NAC, pathological complete responders (pCR) were separated from non-pCR according to their HI (-44 ± 12 and 43 ± 17, p = 3 × 10 − 8 , respectively). We conclude that the HS function is a biomarker that can be used to visualize spatial heterogeneities in lesions, and the baseline HI prior to therapy correlates with chemotherapy pathological response. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). (DOI: 10.1117/1.3638135)
Wideband direction finding using a photonic robust symmetrical number system technique

Dual electrode Mach–Zehnder modulators (DE-MZMs) are used to conduct phase detection for direct wideband direction finding (DF) of microwave signals. It is demonstrated theoretically and through simulation and experimentation that the normalized magnitude of the output signal phase detector circuit is equal to |sin(ψ/2)|, where ψ is the phase difference between the plane waves arriving at the reference and measurement antennas of a linear DF array. A four-element wideband photonic DF system with robust symmetrical number system preprocessing is presented. Simulation and experimental testing results are provided to demonstrate the theoretical concept. The results demonstrate a direct DF receiver using DE-MZMs that achieves fine angular resolution using a much smaller array size than is typically required for linear arrays employing super-resolution signal processing techniques.
ISOLATION AND LONG-TERM SERIAL CULTIVATION OF ENDOTHELIAL CELLS FROM THE MICROVESSELS OF THE ADULT HUMAN DERMIS

A method to isolate and maintain microvascular endothelial cells from the cutaneous vessels of adult human skin in long-term culture has been developed. Endothelial cells lining the microvessels of the papillary dermis are released from surrounding tissue during a brief trypsin incubation (0.3% trypsin, 1% EDTA). Cells are plated onto a fibronectin substrate and maintained in Leibovitz (L15) culture medium containing pooled human serum (50%) and antibiotics. Proliferation is dependent upon the presence of several additional growth factors, cholera enterotoxin (1×10−9M), isobutyl methylxanthine (3.3×10−5M), and medium conditioned by explant culture of the mouse EHS sarcoma. Using this supplemented medium, cells proliferate readily and can be cultivated serially for more than 6 passages (3 months in vitro). These cells retain their characteristic endothelial cell morphology, stain positively for Factor VIII antigen, and contain Weibel-Palade bodies.
An Even Harmonic Quadrature Mixer with a Simple Filter Configuration and an Integrated LTCC Module for W-CDMA Direct Conversion Receiver

This paper presents an even harmonic quadrature mixer (EH-QMIX) with a simple filter configuration and an integrated LTCC module including LNAs, band rejection filters (BRFs), and the proposed EH-QMIX for W-CDMA direct conversion receiver (DCR). Since the DCR has no spurious responses, a BRF instead of a high-Q band pass filter can be applicable for eliminating undesired signals and it can be built in the LTCC substrates easily. As LO frequency'is half of RF frequency in the EH-QMIX, diplexer can be composed of simple filters and it can be also integrated in the substrates. As a result, the whole RF circuits of the EH-DCR using a proposed EH-QMIX are integrated in the LTCC module and miniaturization of the receiver is achieved. Moreover, in order to suppress the degradation of the amplitude and the phase imbalances in the quadrature mixer caused by interferences of signals, RF characteristics of the circuits in the mixer such as reflection coefficients, isolations are discussed. A developed LTCC module shows good performances for W-CDMA direct conversion receiver.
Short-Duration Holocene Lakes in the Mojave River Drainage Basin, Southern California

Stratigraphic, sedimentologic, and pedologic studies of beach ridge and lacustrine deposits indicate that up to five times during the Holocene, shallow lakes covered Silver Lake playa in southeastern California for periods of years to decades. The two youngest lacustrine events (at about 390 ± 90 yr B. P. and 3620 ± 70 yr B. P.) coincide with the early and late Neoglacial episodes of North America. Increasing evidence in recent years from other nonglaciated areas leads us to conclude that the effects of these climatic episodes were much more widespread than previously thought. The climate during these episodes was characterized by an increased frequency of winter storms in the southwestern United States, causing wetter conditions that affected diverse, hyperarid environments in the Mojave Desert and adjacent regions. We propose that this wide areal coverage was caused by large-scale, winter atmospheric circulation patterns, which are probably related to changes in sea-surface temperatures and oceanic circulation in the eastern North Pacific Ocean.
Long-term effects of parent weight on child weight loss.

This study was designed to assess the effects of parent weight (two nonobese/at least one obese parent) and child self-management or parent management on weight change of obese children over 5 years of observation. No differential effects of the two treatments were shown, but parent weight was associated with outcome. We have previously shown obese children with nonobese parents demonstrate similar relative weight changes over the first 6 months of treatment, but, from months 6 to 12, children with nonobese parents maintained their losses, while children with obese parents began to return to baseline relative weights (Epstein, Wing, Koeske, & Valoski, 1986). The present report shows maintenance of relative weight differences due to parent weight after 5 years of observation.
QPO in transient pulsars

Abstract QPOs have now been observed from five transient X-ray pulsars. Four of these are in Be/X-ray systems, and one is the newly discovered LMXB transient GRO J1744-28. I review the observations, and discuss their interpretation in terms of the beat or Keplerian frequency models. These models are successful in explaining the observations for two of the Be/X-ray transients. For one of these, A0535+262, the observations constrain the ratio of the radius of the accretion disk inner edge to the Alfven radius, providing new information on the accretion disk-magnetosphere boundary region. Neither model can explain the QPO in the remaining two Be/X-ray systems, nor that in GRO J1744-28. It is likely therefore that two or more QPO mechanisms are at work. I discuss the potential for gaining new insight into QPOs from analysis tools unique to pulsed systems, and discuss what we can learn from new observations.
Characterization of primary and secondary forms of Xenorhabdus luminescens strain Hm

Cultures of the primary form of Xenorhabdus luminescens strain Hm gave rise to secondary forms after prolonged static incubation in two broth media. The secondary forms were deficient in pigmentation and extracellular antibiotic, protease and lipase activities, and were about 100-fold less luminous than the primary form in vivo. Secondary forms isolated on two separate occasions from two different media were identical in their deficiencies. Cultures of the secondary form in defined broth media produced no detectable secondary metabolites, unlike the primary form, and grew more rapidly than the primary form. A protocol for screening primary cultures of X. luminescens for secondary forms is presented.
Revisiting the Foundations of IR: Timeless, Yet Timely

As we face an explosion of potential new applications for the fundamental concepts and technologies of information retrieval, ranging from ad ranking to social media, from collaborative recommending to question answering systems, many researchers are spending unnecessary time reinventing ideas and relationships that are buried in the prehistory of information retrieval (which, for many researchers, means anything published before they entered graduate school). Much of today's received wisdom may be nothing more than the fossilized residue of lively debates concerning such things as . estimation of value and evaluation of systems. Returning to those discussions may open the door to genuinely new insights. On the other hand, of the ideas that surface as "new" in today's super-heated research environment have very firm roots in earlier developments in fields as diverse as citation analysis, statistics, and pattern recognition. The purpose of this tutorial is to survey those roots, and their relation to the contemporary fruits on the tree of information retrieval, and to separate, as much as is possible in an era of increasing commercial secrecy about methods, the problems to be solved, the algorithms for solving them, and the heuristics that are the bread and butter of a working operation. Among the important new topics whose foundations will be explored are the use of social media in search and advertising, and the growing management of personal image collections for search and for commercial purposes. While some might think that an examination of the roots is of merely historical interest, it has practical value as well. When you know which earlier research has provided the origins for the things that you are interested in, you can use that fact to trace its other descendents, and often find rich and rewarding ideas in a literature that you would not normally reach, because it was not considered important by your instructors when you were learning about the problems. In addition to pattern recognition and citation analysis, the tutorial will also expose and review some of the relations to the fields of statistics and operations research. Participants will become familiar with roots in Pattern Analysis, Statistics, Information Science and other sources of key ideas that reappear in the current development of Information Retrieval as it applies to Search Engines, Social Media, and Collaborative Systems. They will be able to separate problems from algorithms, and algorithms from heuristics, in the application of these ideas to their own research and/or development activities. Course materials will be made available on a Web site two weeks prior to the tutorial. They will include links to relevant software; links to publications that will be discussed; and mechanisms for chat among the tutorial participants, before, during and after the tutorial.
Effect of CXCL-1/KC production in high risk vascularized corneal allografts on T cell recruitment and graft rejection.

Background. The survival rate of corneal allografts in high-risk vascularized corneal bed recipients is poor, similar to vascularized solid organ allografts. Although the early induction of selective chemokines in solid organs is required for the optimal recruitment of T cells into rejecting allografts, little is known about the role of these chemokines in high risk corneal allografts. Methods. Orthotopic corneal allotransplants were performed in low-risk (nonvascularized) and high-risk (vascularized) C57BL/6 (H-2b) recipients using Balb/c (H-2d) donors. Intragraft production of CXC chemokines was measured by Luminex and enzyme-linked immunosorbent assay on corneal transplant extracts at different times after surgery. Rabbit anti-KC serum was used to test its role in high risk corneal allograft survival. Results. Early upregulation of CXCL1/KC occurs 3 days after transplantation in high risk allograft only. Moreover, the T-cell chemoattractants, CXCL9/Mig and CXCL10/IP10, are produced late (day 10) after surgery and their production correlates with the recruitment of CD4 T cells into the graft. Furthermore, in vivo neutralization of CXCL1/KC with anti-KC sera results in increased graft survival and decreased recruitment of T cells into high-risk allografts. Conclusion. We propose that a high risk vascularized cornea behaves like a vascularized solid organ transplant. The early production of CXCL1/KC is crucial to the induction of T-cell chemoattractants necessary for the recruitment of allospecific CD4 T cells into the graft. In vivo neutralization of CXCL1/KC represents a potential novel therapy that could be used to increase the survival rate of high-risk vascularized corneal allografts.
INBONE Total Ankle Arthroplasty

The INBONE total ankle replacement has been in use since 2005. Although studies are not available regarding its success, it is increasingly being used because of its unique design. This design features a wide modular tibial stem onto which additional components can be added to increase its length and a talar component with a modular stem. A leg holder is used with the aid of fluoroscopy in attaining alignment during insertion. The design helps the surgeon deal with severe deformity, tibial bone loss, distal tibia infarction and revision total ankle arthroplasty. This article details the techniques used for its insertion.
Kinematic structure and mesoscale variability of the rim current near the coast of Crimea (according to the data of instrumental measurements in September 2008)

By using the results of processing of the instrumental data with high space resolution obtained in September 2008, we analyze the structure of the Rim Current in the upper 100-m layer near the coast of Crimea. We determine the statistical characteristics of the mesoscale fluctuations of currents according to the data of 1165 vertical probes. It is shown that the kinetic energy of intense mesoscale perturbations observed in the vicinity of the Rim Current is of the same order of magnitude as the kinetic energy of the mean current.
Atomic layer deposited high-k nanolaminate capacitors

Abstract Al2O3–Ta2O5 nanolaminate films were prepared via atomic layer deposition (ALD) on silicon with a single overall composition and thickness, but with a varying number of Al2O3/Ta2O5 bilayers. The composition of the films was roughly 57% Al2O3 and 43% Ta2O5 and the total film thickness was held at ∼58 nm, while the number of bilayers was varied from 3 to 192 by changing the target bilayer thickness from ∼19.2 nm to ∼0.3 nm. Varying the number of bilayers was found to impact electrical properties. Although, almost all laminate films exhibited leakage, breakdown, hysteresis, and overall dielectric constant intermediate between pure Al2O3 and Ta2O5 films, laminates with few bilayers exhibited leakage current density lower than Al2O3 over the range of ∼3.5–4.5 MV/cm. Select samples annealed at temperatures from 400 to 900 °C were compared with as-deposited laminates. Annealing the laminate films at low temperatures improved leakage and breakdown while higher temperature anneals degraded both leakage and breakdown but improved the effective dielectric constant. A figure of merit was used to evaluate the overall ability of the various films to store charge. It was found that the few bilayer laminates were ranked higher than the many bilayer laminates as well as above both the pure Ta2O5 and pure Al2O3 films. These results indicate that even for a fixed overall composition, the electrical properties of a nanolaminate can be adjusted by varying the number of bilayers.
A chemical theory for the thermodynamics of highly-solvated liquid metal mixtures

Chemical solution theory has been shown to be particularly well-suited for certain classes of liquid metal mixtures. A generalized formulation of this approach is presented and it eliminates the need for mechanistic information. The results are in good agreement with many data, and could lead to a variety of industrial applications of liquid metal solvents.
Enhanced prostaglandin synthesis in the parturient rat uterus and its effects on myometrial oxytocin receptor concentrations.

Abstract We measure oxytrocin (OT) responsiveness and prostaglandins (PGs) synthesis in uteri of 19, 20, 21 and 22-day pregnant and 2-day postpartum rats to determine whether the enhanced OT sensitivity and PG synthesis in the parturient uterus is the result of a higher cyclooxygenase activity. We also investigated the effects of suppression of PG synthesis on OT responsiveness and OT receptor in 22-day and 23-day pregnant rats. PG productions (PGE 2 , PGF 2α , 6-keto-PGF 1α and TXB 2 in microsomal fractions were quantitated by radio- immunoassays (RIAs). OT receptor concentrations were measured in plasma membrane fractions by radioligand-receptor binding assays. Naproxen sodium was used to inhibit endogeneous PG synthesis. We found a close temporal relationship between enhanced OT responsiveness and increased uterine PGE 2α synthesis, but no significant difference in cyclooxygenase activities among the microsomes prepared from uteri of different gestational ages. Suppression ofPG synthesis attenuated OT responsiveness and markedly reduced OT binding sites, from 242 to 78 fmol/mg protein. There was no change in the binding affinity. These findings suggest that PG stimulates OT receptor formation which leads to enhanced OT responsiveness. The increase in PG production is not mediated by a higher cyclooxygenase activity.
Constancy of Specific Rotation with Age in Natural Egg White

Abstract THE occasional occurrence of a relatively large proportion of watery white in fresh eggs and the slow liquefaction of the firm white which may take place in stored eggs have been explained in several ways. It is known that an egg may undergo a progressive liquefaction of the thick white in the absence of destructive micro-organisms, hence several investigators have explained these processes by assuming various types of chemical breakdown in the protein substance of the egg white. Sharp and Powell (1927) and Sharp (1929) suggest a hydrolysis of the proteins induced by the alkaline condition which the white may attain under improper storage. St. John and Green (1928) arrive at the conclusion that the difference between watery white and firm fresh white is not of the same nature as the difference between fresh and storage eggs. Their work does not appear to take into account the natural variation in . . .
Study on Porcelain Acoustic Emission Signal Based on All Phase Spectrum Analysis

In order to differentiate the porcelain quality, the paper introduces the All Phase spectrum analysis technology and studies on analyzing porcelain acoustic emission (AE) signal. As for the energy leakage by traditional signal truncation method in processing the signal, the all phase truncation method somewhat reduce the leakage which affects the follow-up porcelain quality discrimination. All instances consisting sample point are considered and weighted average technology is introduced to make amplitude-frequency clearer. According to the simulation, the energy leakage based on all phase signal processing is weakened and the spectrum is able to be accurate. It is more beneficial to the follow-up porcelain quality discrimination.
Frequency adaptability and waveform design for OFDM radar space-time adaptive processing

We propose an adaptive waveform design technique for an orthogonal frequency division multiplexing (OFDM) radar signal employing a space-time adaptive processing (STAP) technique. We observe that there are inherent variabilities of the target and interference responses in the frequency domain. Therefore, the use of an OFDM signal can not only increase the frequency diversity of our system, but also improve the target detectability by adaptively modifying the OFDM-coefficients in order to exploit the frequency-variabilities of the scenario. First, we formulate a realistic OFDM-STAP measurement model considering the sparse nature of the target and interference spectra in the spatio-temporal domain. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. With numerical examples we demonstrate that the resultant OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.
Kinetic treatments of glass transition phenomena and viscoelastic properties of glasses

Phenomenological treatments of viscoelasticity and recent models proposed to explain the kinetic aspects of glass transition phenomena are shown to be based on the same underlying physical considerations. This realization suggests the possible unification of these two areas by a single model. This possibility is explored for the simple case of a glass subjected to a single temperature jump followed by a stress relaxation experiment. Presently, sufficient data on any single chemical system to support a critical test of the viability of this model does not exist. Nevertheless, data from several sources on various materials indicate that the qualitative aspects of viscoelastic behavior of glasses at temperatures well below Tg are in accord with the predictions of the unified model.
A new nonlinear coupling of the fundamental and its harmonic overtone thickness shear modes for improvement of resonator Q

Ultra high frequency resonators have higher noise levels due to their greater miniaturization and higher power density. This paper proposes a new method using nonlinear acoustic coupling for improving the resonator Q and hence reducing noise levels in third overtone thickness shear resonators. We show an increase in Q of the third overtone mode of thickness when coupled nonlinearly to the fundamental mode of thickness shear. The Q increase and a steep phase-frequency curve will reduce the phase noise of the third overtone resonator. The nonlinear coupling of the fundamental thickness shear mode to the third overtone thickness shear mode was modeled using MATLAB Simulink. At higher drive levels, the mechanical nonlinearities of the fundamental mode will drive the third overtone thickness shear mode if its resonant frequency is sufficiently close to three times the fundamental thickness shear frequency. This nonlinear coupling will improve the Q of the third overtone thickness shear mode by as much as 15-fold. The Q increase is dependent on (1) frequency matching of the third overtone mode to three times the fundamental mode, (2) the drive level of the fundamental mode, and (3) the relative phase of the fundamental drive to the third overtone drive.
Creating conditional mutations in mammals

For many years geneticists have relied on conditional activation to study the roles of cytolytic or cytostatic proteins in lower eukaryotes or to elucidate the epistatic relationships of proteins in a signaling pathway. Regardless of their merits, conditional mutants have only been available to mammalian geneticists within the past few years. Moreover, the approaches that exist are still limited to a subset of signaling molecules and are not reliable for in vivo studies. Now, added to the biologist's toolbox is a versatile new approach based on chemically induced dimerization that should allow for the reversible regulation of proteins at the cell surface, intracellularly, in the nucleus and in vivo.
A bipolar planar near-field measurement system for compact millimeter-wave antenna arrays

Small millimeter-wave antenna designs present particular difficulties when measured. With most available antenna chambers and ranges originally designed for larger size and lower frequencies, physically smaller antennas are dwarfed by the large support structures and cannot be efficiently characterized. Modification of these existing ranges for small antennas and high frequencies may prove to be very difficult as large positional and RF equipment are not easily modified or replaced. Additionally, equipments associated with millimeter-wave antenna measurements such as vector network analyzers, high frequency cable, and adapters, are typically very expensive and often exceed the cost of the rest of the system. With such difficulties, a custom antenna range, designed for the smaller size antennas operating at millimeter-wave frequencies is an attractive and cost-effective solution. In this presentation, a novel portable millimeter-wave bipolar planar near-field antenna measurement system is introduced.
A Processable Shape Memory Polymer System for Biomedical Applications

Polyurethane shape memory polymers (SMPs) with tunable thermomechanical properties and advanced processing capabilities are synthesized, characterized, and implemented in the design of a microactuator medical device prototype. The ability to manipulate glass transition temperature (Tg ) and crosslink density in low-molecular weight aliphatic thermoplastic polyurethane SMPs is demonstrated using a synthetic approach that employs UV catalyzed thiol-ene "click" reactions to achieve postpolymerization crosslinking. Polyurethanes containing varying C=C functionalization are synthesized, solution blended with polythiol crosslinking agents and photoinitiator and subjected to UV irradiation, and the effects of number of synthetic parameters on crosslink density are reported. Thermomechanical properties are highly tunable, including glass transitions tailorable between 30 and 105 °C and rubbery moduli tailorable between 0.4 and 20 MPa. This new SMP system exhibits high toughness for many formulations, especially in the case of low crosslink density materials, for which toughness exceeds 90 MJ m(-3) at select straining temperatures. To demonstrate the advanced processing capability and synthetic versatility of this new SMP system, a laser-actuated SMP microgripper device for minimally invasive delivery of endovascular devices is fabricated, shown to exhibit an average gripping force of 1.43 ± 0.37 N and successfully deployed in an in vitro experimental setup under simulated physiological conditions.
Review: Molecular Approaches to the Study of Atrial Natriuretic Factor

Application of recombinant DNA technology to the study of atrial natriuretic factor (ANF) has significantly increased our understanding of the biochemistry and physiology of this cardiac hormone. Molecular characterization of the ANF gene and mRNA has yielded structural details about this peptide, and provided tools to investigate maturation, storage, and secretion of a cardiac hormone. Genetic probes have facilitated analyses of the role of a natriuretic and vasorelaxant hormone in pathophysiologic states. Furthermore, studies on the regulation of this cardiac gene have begun to provide data on the molecular basis for biochemical changes in the heart that occur in response to physiologic and pathologic processes.
Fast Macromodeling Technique of Sampled Time/Frequency Data Using z-domain Vector-Fitting Method

The vector-fitting algorithm has been used as the main macromodeling tool for approximating frequency domain responses of complex interconnects and electrical packages [5]. In this paper, a new methodology is proposed to fit transfer functions of frequency or time response data obtained from numerical electromagnetic simulation or measured frequency-domain or time-domain response data. This new method, z-domain vector-fitting (ZDVF), is a formulation of vector-fitting method in the z domain; it has an advantage of faster convergence and better numerical stability compared to the s-domain vector-fitting method (VF). The fast convergence of the method reduces the overall macromodel generation time. The accuracy, numerical stability and convergence speed of VF and ZDVF are compared. Examples are provided to demonstrate the advantage of the ZDVF.
Error-prone polymerization by HIV-1 reverse transcriptase : contribution of template-primer misalignment, miscoding, and termination probability to mutational hot spots

We have observed previously that DNA template-directed polymerization by the type 1 human immunodeficiency virus reverse transcriptase is error-prone for single-nucleotide substitution, addition and deletion errors at homopolymeric sequences. We have also noted strong termination of processive synthesis at these positions (Bebenek, K., Abbotts, J., Roberts, J. D., Wilson, S. H., and Kunkel, T. A. (1989) J. Biol. Chem. 264, 16948-16956). Here we have tested three models to explain errors at these hot spots: template-primer misalignment for deletion errors, and dislocation and direct miscoding for substitution errors. The approach involves introducing single-nucleotide changes within or flanking the homopolymeric hot spots and examining the effects that these changes have on human immunodeficiency virus type 1 (HIV-1) reverse transcriptase error rate, error specificity, and termination probability. The results obtained suggest that single-nucleotide deletion errors in homopolymeric runs result from template-primer misalignment and that both direct miscoding and template-primer dislocation contribute to the base substitution hot spots. The data also suggest that base substitution errors at one position can be templated by the preceding nucleotide or either of the next two nucleotides. Frameshift error rates at homopolymeric sites were affected by changes in the sequences flanking the runs, including single-nucleotide differences in the single-stranded template strand and in the double-stranded primer region as many as six nucleotides distant from the hot spot. Both increases and decreases in frameshift fidelity were observed, and most of these correlated with concomitant increases or decreases in the probability that HIV-1 reverse transcriptase terminated processive synthesis within the run. These data provide further support for a relationship between the frameshift fidelity and the processivity of DNA-dependent DNA synthesis by HIV-1 reverse transcriptase.
Neutrophil C5a Receptor and the Outcome in a Rat Model of Sepsis

Complement fragment 5a (C5a)-C5a receptor (C5aR) signaling plays an essential role in neutrophil innate immunity. Blockade of either the ligand or the receptor improves survival rates in experimental sepsis. In the current study, sepsis was induced in rats by cecal ligation/puncture. Early in sepsis C5aR content on neutrophils significantly dropped, reached the nadir at 24 h after onset of sepsis, and progressively elevated thereafter. Western-blot, RT-PCR, and confocal microscopy analyses revealed that the loss and re-expression of C5aR during sepsis might be due, at least in part, to the receptor internalization and reconstitution. The reduction and reconstitution of C5aR correlate with the loss and restoration of innate immune functions of blood neutrophils (chemotaxis and reactive oxygen species production), respectively. Quantitative measurements of C5aR on blood neutrophils are highly predictive of survival or death during sepsis. These data suggest that neutrophil C5aR content represents an essential component of an efficient defense system in sepsis and may serve as a prognostic marker for the outcome.
The paradoxical effect of bevacizumab in the therapy of malignant gliomas

One rationale behind the use of agents that inhibit vascular endothelial growth factor in the therapy of primary CNS malignancies is based upon the concept that normalization of tumor vasculature with a decrease in tumor interstitial pressure will improve access of cytoreductive drugs and improve radiotherapy efficacy due to increased oxygen delivery. However, several studies have raised the concern that these agents may both rapidly restore the low permeability characteristics of the blood–brain barrier and counteract the beneficial effect of pseudoprogression. The result may be decreased therapeutic efficacy while increasing infiltration by co-opting normal vessels. In this discussion, we examine both histologic and radiographic tumor progression in the context of antiangiogenic agents. Issues dealing with the safety of bevacizumab (Avastin®, Genentech, South San Francisco, CA) and its potential to decrease efficacy of standard radiochemotherapy when used to treat patients with newly diagnosed malignant glioma are emphasized.
Kin Selection in the Annual Plant Impatiens capensis

Kin selection occurs when phenotypic variation in a character or set of characters is heritable, spatially structured, and has differential fitness effects on neighboring individuals. Spatially structured, heritable variation has been found for many characters of the annual plant Impatiens capensis (the first two criteria). By manipulating plant growth by apical removal, I show that Impatiens fitness is strongly influenced by the phenotypes of neighboring plants, corroborating a previous study. A specific suite of phenotypes relating to plant architecture is consistently beneficial to neighboring plants. In addition, these manipulative experiments sug- gest that phenotypic plasticity may often impede purely observational field studies of kin selec- tion in plant populations.
Selection for Virulent Dengue Viruses Occurs in Humans and Mosquitoes

Dengue is the most common mosquito-borne viral disease in humans. The spread of both mosquito vectors and viruses has led to the resurgence of epidemic dengue fever (a self-limited flu-like syndrome) and the emergence of dengue hemorrhagic fever (severe dengue with bleeding abnormalities) in urban centers of the tropics. There are no animal or laboratory models of dengue disease; indirect evidence suggests that dengue viruses differ in virulence, including their pathogenicities for humans and epidemic potential. We developed two assay systems (using human dendritic cells and Aedes aegypti mosquitoes) for measuring differences in virus replication that correlate with the potential to cause hemorrhagic dengue and increased virus transmission. Infection and growth experiments showed that dengue serotype 2 viruses causing dengue hemorrhagic fever epidemics (Southeast Asian genotype) can outcompete viruses that cause dengue fever only (American genotype). This fact implies that Southeast Asian genotype viruses will continue to displace other viruses, causing more hemorrhagic dengue epidemics.
Hydraulic, biomechanical, and anatomical interactions of xylem from five species of Acer (Aceraceae)

Possible trade-offs between hydraulic conductivity and mechanical properties of woody stems from five species were assessed. Acer negundo is a ruderal tree, A. saccharinum, and A. rubrum are fast-growing and shade-intolerant soft maples, whereas A. nigrum and A. saccharum are slow-growing and shade-tolerant hard maples. It was hypothesized that the ruderal and soft maples would have lower modulus of elasticity (MOE) and modulus of rupture (MOR), but higher maximum specific conductivity (K(s max)) than hard maples. Many anatomical and general morphological characteristics were measured in an attempt to correlate them to water transport and/or mechanical strength differences between species. No difference was found between species in vessel diameter, fiber wall thickness, initial hydraulic conductivity (K(h initial)), specific conductivity (K(s max)), native percent embolism, or Huber value. Similarly, no trade-off was found between K(s max) and MOE or MOR across the genus. However, fiber lumen diameter was inversely correlated to MOE and MOR. Surprisingly, percentage of ray parenchyma was positively related to MOE. The results suggest transport/mechanical trade-offs do not occur in Acer and differences in mechanical properties may be due to fiber lumen differences that do not influence the efficient transport of water.
Dynamics of all-optical clock recovery using two-section index- and gain-coupled DFB lasers

The dynamics of coherent clock recovery (CR) using self-pulsing two-section distributed feedback (TS-DFB) lasers have been investigated. Both simulation and experimental results indicate fast lockup and walk-off of the clock-recovery process on the order of nanoseconds. Phase stability of the recovered clock from a pseudorandom bit sequence (PRBS) signal can be achieved by limiting the detuning between the frequency of free-running self-pulsation and the input bit rate. The simulation results show that all-optical clock recovery using TS-DFB lasers can maintain a better than 5% clock phase stability for large variations in power, bit rate, and optical carrier frequency of the input data and therefore is suitable for applications in optical packet switching.
Extrarenal vascular anatomy of kidney: Assessment of variations and their relevance to partial nephrectomy

Abstract Objectives To evaluate the feasibility of selective segmental artery clamping during partial nephrectomy. Methods Precise extraparenchymal renal hilar dissection was performed on 73 fixed cadaveric kidneys. The surgical accessibility to clamping of each presegmental and segmental artery from the anterior and posterior approaches was determined on the basis of vessel length, position within the renal hilum, and degree of overlying collecting system or venous structures. Results The vascular anatomy consisted of zero, one, or two presegmental arteries (extrarenal main renal artery branches that split into two or more segmental arteries) in 49.3%, 31.5%, and 19.2% of the kidneys, respectively. From a posterior approach, the posterior segmental artery was accessible to isolated clamping in 81.8% of the kidneys (segmental accessibility rate) and was accessible to clamping at the presegmental level in 12.7% (presegmental accessibility rate) for a total accessibility rate of 90.9%. The total accessibility rate for the inferior segmental artery was 88.5% from an anterior and 66.7% from a posterior surgical approach. The apical artery total accessibility rate was 72.3% and 40.5% from an anterior and posterior approach, respectively. The corresponding middle and superior segmental artery total accessibility rates were 50.8% and 32.8%. Conclusions In this cadaveric model, hilar dissection and clamping of the renal segmental arteries is anatomically feasible in most cases. Posterior and polar tumors will likely be more amenable to segmental vascular control. Selective segmental vascular control may offer the benefits of total hilar control while reducing overall renal ischemic injury.
Inhibition of triazolam clearance by macrolide antimicrobial agents: In vitro correlates and dynamic consequences

Background Macrolide antimicrobial agents may impair hepatic clearance of drugs metabolized by cytochrome P4503A isoforms. Potential interactions of triazolam, a substrate metabolized almost entirely by cytochrome P4503A in humans, with 3 commonly prescribed macrolides were identified using an in vitro metabolic model. The actual interactions, and their pharmacodynamic consequences, were verified in a controlled clinical study. Methods In an in vitro model using human liver microsomes, 250 μmol/L triazolam was incubated with ascending concentrations (0 to 250 μmol/L) of troleandomycin, azithromycin, erythromycin, and clarithromycin. In a randomized, double-blind, 5-trial clinical pharmacokinetic-pharmacodynamic study, 12 volunteers received 0.125 mg triazolam orally, together with placebo, azithromycin, erythromycin, or clarithromycin. In a fifth trial they received placebo plus placebo. Results Mean 50% inhibitory concentrations versus 4-hydroxytriazolam formation in vitro were as follows: 3.3 μmol/L troleandomycin, 27.3 μmol/L erythromycin, 25.2 μmol/L clarithromycin, and greater than 250 μmol/L azithromycin. Apparent oral clearance of triazolam when given with placebo or azithromycin was nearly identical (413 and 416 mL/min), as were peak plasma concentrations (1.25 and 1.32 ng/mL) and elimination half-life (2.7 and 2.6 hours). Apparent oral clearance was significantly reduced (P < .05) during erythromycin and clarithromycin trials (146 and 95 mL/min). Peak plasma concentration was correspondingly increased, and elimination half-life was prolonged. The effects of triazolam on dynamic measures were nearly identical when triazolam was given with placebo or azithromycin, but benzodiazepine agonist effects were enhanced during erythromycin and clarithromycin trials. Conclusion The in vitro model identifies macrolides that may impair triazolam clearance. Anticipated interactions, and their pharmacodynamic consequences in volunteer subjects, were verified in vivo. Clinical Pharmacology & Therapeutics (1998) 64, 278–285; doi:
Tinea Capitis: Predictive Value of Symptoms and Time to Cure With Griseofulvin Treatment

Objectives. To describe (a) the predictive value of symptoms for diagnosis of tinea capitis and (b) the rate and timing of cure with high-dose griseofulvin treatment. Methods. This prospective open-label study enrolled children aged 1 to 12 years with clinical tinea capitis. Participants with a positive dermatophyte culture received oral griseofulvin (20-25 mg/kg/day) and topical selenium sulfide shampoo for 6 weeks. Main outcome measures. The rate of symptoms of tinea capitis, and rates of mycologic and clinical cure. Results. The positive predictive values of any 1, 2, 3, or 4 symptoms for a positive culture were 88%, 82%, 78%, and 77%, respectively. The observed rates of mycologic, clinical, and complete cure were 89%, 66%, and 49%, respectively. Conclusion. In a high-risk population it is reasonable to diagnose tinea capitis using one or more cardinal symptoms. Oral griseofulvin at 20 to 25 mg/ kg/day with adjunctive shampooing for 6 weeks is moderately successful as treatment.