cssi/SciSciGPT-SciSciNet huggingface dataset:
Role of P30 in Attachment and Immunity to T. Gondii

Because of its adaptability to the laboratory, most work has focused on the tachyzoite stage of T. gondii. [reviewed in Kasper et al., 1992]. Of the several antigens recognized by the immune sera Ig fraction, the most prevalent has a Mr of 30Kd. Most work to date on the various toxoplasma antigens has concentrated on either the 30Kd (P30) or 22Kd (P22) proteins. Of the two, P30 is the major iodinated protein on a number of geographically diverse human and animal isolates of toxoplasma [Ware and Kasper, 1987]. Analysis of the gene encoding the P30 molecule show it to be highly conserved with only an 8 amino acid variation among tested strains. The P30 gene is single- copy and contains no introns [Burg et al, 1988]. This molecule comprises 3–5% of the total parasite protein and is a major component of the vesicular network within the parasitophorous vacuole [Sibley et al, 1986]. Intact intra- and extracellular parasites show a homogeneous distribution of P30; however, upon invasion of the host cell, most of the monoclonal antibody against P30 is shed from the tachyzoite [Dubremetz et al, 1985]. Mono- and polyclonal antibody against P30 is parasiticidal to extracellular T. gondii in the presence of serum complement [Kasper et al, 1987]. By competition binding assay, a single monoclonal directed against P30 can inhibit 25–30% of the specific binding of human immune serum to toxoplasma, sugesting that P30 is the most immunogenic constituent of the tachyzoite and that a single region of this molecule may contain most of the immunogenic activity.
Microanalysis with Ionization-Loss Electrons

In the previous two chapters we’ve described how to acquire an energy-loss spectrum and have also given you some idea of the information in such spectra. Most importantly, there are elemental composition data which can be extracted primarily from the high-loss ionization edges. In this chapter we’ll examine how to get this information and quantify it. As we’ve already indicated, the prime use for these kind of data is light-element microanalysis, where EELS complements XEDS. First we’ll remind you of the experimental variables over which you have control, because these are rather critical. Then we’ll discuss how to obtain a spectrum and what it should look like for microanalysis. Next, we’ll discuss the various quantification routines which, in principle, are just as straightforward as those for XEDS but in practice require a rather more sophisticated level of knowledge to carry them out successfully. Finally, we’ll say a bit about spatial resolution and minimum detectability, although these topics aren’t as important in EELS as they are in XEDS.
The Electron Affinities of C3O and C4O

We predict the adiabatic electron affinities of C3O and C4O based on electronic structure calculations, using a large triple-ζ basis set with polarization and diffuse functions (TZ2Pf+diff) with the SCF, CCSD, and CCSD(T) methods as well as with the aug-cc-pVDZ and aug-cc-pVTZ basis sets. Our results imply electron affinities for C3O and C4O; EA(C3O) = 0.93 eV ± 0.10 and EA(C4O) = 2.99 ± 0.10. The EA(C3O) is 0.41 eV lower than the experimental value of 1.34 ± 0.15 eV, while the EA(C4O) is 0.94 eV higher than the experimental value of 2.05 ± 0.15 eV. Optimized geometries for all species at each level of theory are given, and harmonic vibrational frequencies are reported at the SCF/TZ2Pf+diff and CCSD/aug-cc-pVDZ levels.
Concepts in the Study of Animal Behavior

Several of Danny Lehrman’s papers show what a great interest he had in the nature of the concepts that are used by students of animal behavior. Historians of science have demonstrated again and again how important a searching analysis of concepts is for the progress of science. A change of concepts, or a drastic reformulation of existing concepts, may lead to a veritable scientific revolution.
Associations Between Maternal Body Mass Index, Gestational Weight Gain, Maternal Complications, and Birth Outcome in Singleton, Term Births in a Largely Non-Hispanic White, Rural Population.

Abstract Background: In 2009, the Institute of Medicine (IOM) published guidance on gestational weight gain (GWG) modified by body mass index (BMI). GWG outside of IOM recommendations negatively af...
The Impact of Mutual Monitoring and Enterprise System Integration on the Empowerment of Managers

Companies are increasingly adopting enterprise systems in order to realize the significant operational advantages they convey. These benefits include reductions in operating costs, improved custome...
Trends in Management and Outcomes Among Patients with Urothelial Carcinoma Undergoing Radical Cystectomy from 1995 to 2015: The Memorial Sloan Kettering Experience.

Purpose:We evaluated trends in oncologic characteristics and outcomes as well as perioperative management among patients undergoing radical cystectomy at Memorial Sloan Kettering from 1995 to 2015....
Harry Newman. Impressive Shakespeare: Identity, Authority and the Imprint in Shakespearean Drama. New York: Routledge, 2019. Pp. xviii, 199.

This review considers Impressive Shakespeare: Identity, Authority and the Imprint in Shakespearean Drama.
Scaling Laws of Paleoindian Projectile Point Design

Across late Pleistocene North America, Paleoindians designed a variety of projectile point styles that vary in form over time and space, but also share similar performance requirements and a common technological history. In order for projectile points to be effective components of hunting weaponry, at a minimum they must be engineered to be both effective at penetrating prey and robust to failure. These universal performance criteria suggest the design space underlying the diversity of projectile point styles we observe in the archeological record must be highly constrained by engineering principles. Here, using a large sample of complete points (n = 2360) from 16 Paleoindian projectile point types we examine the diversity of Paleoindian projectile point designs using a combination of engineering principles, allometric scaling theory, and statistical models. First, we define the design space of Paleoindian projectile points by examining the dimensions of length, width, and thickness that define the basic three-dimensional volumes of the points and their size allometries. Second, we derive three hypotheses for the optimal allometric design of points from first principles of engineering that quantify design trade-offs between robustness and penetration capability. We then test the predictions of the hypotheses with data and show that the empirical observations match the theoretical predictions in almost every case. Our analysis shows that Paleoindian projectile points are engineered to resist breaking while maximizing penetrating capabilities, and we show the engineering principles behind this optimization. We also show that within these design criteria, some types are designed to emphasize penetration, whereas others emphasize robustness. These results demonstrate that once bifacial point traditions emerge in Paleoindian North America there is a high retention of design, engineering, and performance criteria throughout the Paleoindian record, and probably beyond.
Reply to Comment on ‘Forbidden collisions’

A recent Comment by Rizcallah on a paper on Forbidden Collisions (Binder et al Phys. Educ. 55 033010) is hereby examined. Both the Comment and this Reply illustrate the subtleties of discussing and understanding collisions in one dimension.
Influence of Highway Pavement on Metals in Road Dust: a Case Study in Houston, Texas

The elemental analysis of road dust can be used to determine the contribution of traffic-related metal emissions to the local environment. Previous studies have shown that brake wear, tire wear, and lead wheel weights release significant amounts of metals that lead to decreased biodiversity and degradation of urban streams. Highway pavement has not previously been considered as a source of metal inputs into the environment. To determine the extent that highway pavement contributes to metal loads in the local environment, road dust and pavement samples were collected for both asphalt and concrete pavement types on State Highway 59 in Houston, TX, USA. Samples were analyzed by ICP-MS to quantitate 9 metals: aluminum (Al), iron (Fe), vanadium (V), chromium (Cr), nickel (Ni), cobalt (Co), copper (Cu), zinc (Zn), and lead (Pb). A chemical mass balance receptor model that is commonly used for source apportionment of air pollution was applied to heavy metals in road dust, with brake dust, tire wear, wheel weights, and pavement materials as the emission sources. Pavement is shown to be the primary source of V, Cr, Ni, and Co in road dust, regardless of asphalt or concrete pavement type. Lead concentration in road dust is influenced by pavement type, with concrete pavement contributing approximately 45% of total lead in concrete road dust, while asphalt pavement only contributes 27% of total lead in asphalt road dust. Fly ash is the likely component of concrete pavement responsible for the higher contribution of Pb. An enrichment factor analysis indicates that Cr, Co, and V have low levels of enrichment compared to Cu, Zn, Pb, and Ni, indicating that pavement wear is generally a minor source of environmental metal contamination compared to brake and tire wear. Currently, brake and tire wear are the non-exhaust vehicle emissions of greatest concern; however, alternatives to fly ash should be considered to further reduce Pb and Ni concentrations in the environment.
A fast asynchronous MCMC sampler for sparse Bayesian inference

We propose a very fast approximate Markov Chain Monte Carlo (MCMC) sampling framework that is applicable to a large class of sparse Bayesian inference problems, where the computational cost per iteration in several models is of order $O(ns)$, where $n$ is the sample size, and $s$ the underlying sparsity of the model. This cost can be further reduced by data sub-sampling when stochastic gradient Langevin dynamics are employed. The algorithm is an extension of the asynchronous Gibbs sampler of Johnson et al. (2013), but can be viewed from a statistical perspective as a form of Bayesian iterated sure independent screening (Fan et al. (2009)). We show that in high-dimensional linear regression problems, the Markov chain generated by the proposed algorithm admits an invariant distribution that recovers correctly the main signal with high probability under some statistical assumptions. Furthermore we show that its mixing time is at most linear in the number of regressors. We illustrate the algorithm with several models.
La conexión entre las percepciones de sesgos mediáticos y su influencia en la polarización afectiva: un examen en Brasil, México y Estados Unidos

This study examines two types of news media-related perceptions (hostile media perceptions and third-person perceptions) and the relationship with affective polarization, or the increased partisan hostility between opposing members in Brazil, Mexico and the United States. Operationalizing affective polarization as the estimated discrepancy between members of one’s own political party and those of others on certain personality traits, including intelligence, caring about the welfare of humanity, being informed, and being tolerant, we found strong and statistically significant positive correlations between each type of perception and affective polarization. In other words, thinking that the media is biased against one’s own side and thinking that partisans on the other side are more susceptible to biased media influence respectively and directly associates with how one feels about adversarial partisans. The implications of these findings are discussed in relation to the prominence of perceptions of media bias and affective polarization in countries with different levels of media professionalism and party polarization.
Population-specific patterns of toxin sequestration in monarch butterflies from around the world

Monarch butterflies are one of the preeminent examples of a toxin-sequestering animal, gaining protection against predators via cardenolides obtained from their milkweed host plants. Although cardenolide sequestration by monarchs has been studied in ecological, physiological, and phylogenetic contexts, relatively little research has surveyed genetic variation in the ability to sequester, nor has monarch sequestration been studied in relation to divergent host plant assemblages or variation in exposure to predation. Here, we use the monarch9s recent global range expansion to test hypotheses about how cardenolide sequestration evolves over relatively contemporary time scales. First, we test for whether sympatric monarch/milkweed combinations have a sequestration advantage by rearing six geographically disparate monarch populations on six associated milkweed host species and measuring levels of sequestered cardenolides in a set of 440 adult butterflies. Second, we use monarchs from Guam - an oceanic island where birds have been functionally extirpated for approximately 40 years - to test hypotheses about how exposure to avian predation affects cardenolide sequestration. We find little overall evidence for increased sequestration on sympatric hosts. However, one monarch population (Puerto Rico) shows strong support for cross-host tradeoffs in sequestration ability, primarily driven by limited sequestration of polar cardenolides from two temperate North American milkweeds (Asclepias syriaca and A. speciosa). Monarchs from Guam show some evidence for reduced cardenolide sequestration in both a cross-island comparison of wild-caught butterflies as well as population-level comparisons of greenhouse-reared butterflies. Our results suggest that there is substantial genetic variation in sequestration ability (both within and between monarch populations) and that evolutionary history and contemporary species interactions may influence patterns of cardenolide sequestration.
Discussion of photoprotection, screening, and risk behaviors with children and grandchildren after melanoma genetic testing

The purpose of the current study was to examine changes in frequency of discussion about melanoma preventive behaviors among adults who received melanoma genetic test reporting and counseling and their children and grandchildren, correspondence of frequency of discussion with intentions, and content of discussions. Participants received CDKN2A/p16 testing and counseling (N = 24, 46 % p16-positive). Discussions about preventive behaviors were assessed before testing and 1 and 6 months post-testing. Intentions to discuss preventive behaviors and perceived preparedness to discuss risk were assessed post-testing. Open-ended questions assessed content of reported discussions. Discussion of preventive behaviors declined following test reporting, with more rapid decline reported by noncarriers. There was a large gap between the percentage of participants who intended to discuss preventive behaviors and who then reported discussions 1 and 6 months after counseling. Participants felt prepared to discuss melanoma risk but also suggested resources to facilitate discussions. Genetic test reporting and counseling alone did not sustain discussions about preventive behaviors for a hereditary cancer with children and grandchildren. The gap between intentions to have discussions and reported discussions has implications for augmentation of counseling to support at-risk families’ discussions about preventive behaviors.
Constellation design for spatial modulation

Conventional amplitude-phase modulations (APMs) are designed such that the minimum Euclidean distance between constellation points is maximized. Unlike these modulations, the error performance of spatial modulation (SM) is not only a function of the Euclidean distances but also the energy of each symbol, i.e. constellation point. Therefore, conventional APM schemes that are designed solely based on the notion of Euclidean distance are not necessarily suitable for SM transmission. In this paper, the constellation design for SM is investigated and it is shown that, by a proper constellation design, a significant performance gain is obtained compared to the well-known phase shift keying (PSK) or quadrature amplitude modulation (QAM). It is shown that in many cases multi-ring star-QAM is a suitable constellation for SM. However, when the number of transmit antennas is large, the numerically derived constellation converges to the conventional phase shift keying (PSK) constellation, especially at small number of receive antennas.
An inverted-F antenna integrated with solar cells for energy harvesting

This paper discusses the integration of an inverted- F antenna with solar cells for power harvesting. The objective is to achieve a multi-source energy collecting system in order to improve the RF to DC conversion efficiency. The inverted-F antenna can be used either for communication or to scavenge the ambient RF energy when connected to the appropriate rectifying circuit. A prototype of the antenna is fabricated and tested as a proof of concept.
Quantitative relationship between potato tuber damage and counts of Pacific coast wireworm (Coleoptera: Elateridae) in baits: seasonal effects

Experimental plots of potatoes were baited with rolled oats in spring to assess the relationship between counts of Pacific coast wireworm, Limonius canus (Coleoptera: Elateridae), and end-of-the-season damage to potato tubers. Baiting was done at seven intervals beginning before planting of potatoes and ending following plant emergence. Injury (percentage of tubers damaged or number of holes per tuber) showed a curvilinear relationship with increasing wireworm counts in baits. Damage increased rapidly with increasing wireworrn numbers at lower densities, eventually ﬂattening out at very high counts. Wireworm counts in baits ﬂuctuated seasonally, increasing from lows obtained during pre-planting samples to a peak just before plant emergence, followed thereafter by declines in counts. Thus, baiting efficiency varied seasonally. Low counts in baits during the pre-planting interval may have been due primarily to low soil temperatures, while declining counts following plant emergence may have been due to the presence of competing food sources (i.e., the seed piece and developing potato plant). I also assessed depth of wireworms in the soil profile between late-March and mid-May, and found that a relatively large percentage (approaching 25% on two dates) of wireworms occurred very deep in the soil (61-91 cm) until soil temperatures at 31 cm approached 17 °C in early- to mid-May. Thus, low counts in baits during the pre-planting samples may also have occurred in part because a proportion of the population was deep in the soil during this time interval. Seasonal variation in baiting efficiency led to date-to-date differences in predicted damage for a given wireworm count. Low efficiency during the preplanting interval would complicate efforts to use pre-planting baiting as a means to predict end-of-the-season tuber damage.
Compliant epitaxial growth of In/sub x/Ga/sub 1-x/As on In/sub 0.25/Ga/sub 0.75/As pseudo-substrates

In this study, a pseudo-substrate is formed using lateral oxidation of an underlying Al/sub 0.98/Ga/sub 0.02/As layer to improve the material quality of a relaxed In/sub 0.25/Ga/sub 0.75/As seeding layer. Photoluminescence measurements, Hall-effect measurements, and cross-sectional transmission electron microscopy (TEM) were used to evaluate the quality of the regrown materials.
Atomic resolution study of the interfacial bonding at Si3N4/CeO2-δ grain boundaries

Using a combination of atomic-resolution Z-contrast imaging and electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope, we examine the atomic and electronic structures at the interface between Si3N4 (101¯0) and CeO2−d intergranular film (IGF). Ce atoms are observed to segregate to the interface in a two-layer periodic arrangement, which is significantly different from the structure observed in a previous study. Our EELS experiments show (i) oxygen in direct contact with the terminating Si3N4 open-ring structures, (ii) a change in the Ce valence from a nominal oxidation state of +3 to almost +4 moving from the interface into the IGF, and (iii) a uniform concentration of Si in the film.
THE EAST BALTIMORE STUDY II. FAMILIAL AGGREGATION OF PLASMA LIPID LEVELS IN JUVENILES IN A BLACK INNER-CITY POPULATION

Familial aggregation of plasma lipid levels among 676 black juveniles, aged less than 20 years and residing in 202 households in East Baltimore, Maryland, was assessed by the intraclass correlation coefficient of residuals from sex-specific cubic regressions on age. Significant aggregation of both plasma cholesterol (r = 0.23, p less than 0.005) and plasma triglyceride (r = 0.27, p less than 0.005) levels were found. In addition, no effect on familial aggregation was found for each of several measures of family structure: number of juvenile household members, closeness in age, all children over 9 years of age, or shared surname. Two methods of classifying juvenile household size were compared. An association between classification method and juvenile household size was demonstrated (p less than 0.005) for the distributions of households and of children. The intraclass correlation coefficients for plasma cholesterol and plasma triglyceride for households classified by number of juveniles were higher than the coefficients for the house grouped by the number of juveniles admitted to the study, when compared for each classification number, 2 through 4. Evidence for an effect on familial aggregation of the socioeconomic status was shown by a comparison of intraclass correlation coefficients from households in East Baltimore with those from white and black households from the Columbia Medical Plan which have higher levels of occupation and education. Higher correlations were shown for the groups with higher socioeconomic status, regardless of race.
OVO transcription factors function antagonistically in the Drosophila female germline

OVO controls germline and epidermis differentiation in flies and mice. In the Drosophila germline, alternative OVO-B and OVO-A isoforms have a common DNA-binding domain, but different N-termini. We show that these isoforms are transcription factors with opposite regulatory activities. Using yeast one-hybrid assays, we identified a strong activation domain within a common region and a counteracting repression domain within the OVO-A-specific region. In flies, OVO-B positively regulated the ovarian tumor promoter, while OVO-A was a negative regulator of the ovarian tumor and ovo promoters. OVO-B isoforms supplied ovo(+) function in the female germline and epidermis, while OVO-A isoforms had dominant-negative activity in both tissues. Moreover, elevated expression of OVO-A resulted in maternal-effect lethality while the absence of OVO-A resulted in maternal-effect sterility. Our data indicate that tight regulation of antagonistic OVO-B and OVO-A isoforms is critical for germline formation and differentiation.
Geometric analysis of distributed power control and Möbius MAC design

This paper presents a geometric analysis of the convergence condition for the Foschini-Miljanic power control algorithm. The Mobius transform is exploited for the first time to analyze the convergence condition of the power control algorithm. A novel MAC scheme based on the Mobius transform is proposed for the link scheduling problem and proven to improve spatial reuse by scheduling links in pairs if possible. The peak power constraint of wireless networks is analyzed theoretically, and applications to random networks are explored in detail. Observations from the analysis of peak power constraints are also applied to the design of the MAC scheme Mobius MAC to improve the convergence speed and system performance. Simulation results show that our Mobius MAC can roughly double the performance of CSMA in terms of transport density. Applications to cognitive networks and heterogeneous networks are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Initial value problems in discrete fractional calculus

This paper is devoted to the study of discrete fractional calculus; the particular goal is to define and solve well-defined discrete fractional difference equations. For this purpose we first carefully develop the commutativity properties of the fractional sum and the fractional difference operators. Then a v-th (0 < v ≤ 1) order fractional difference equation is defined. A nonlinear problem with an initial condition is solved and the corresponding linear problem with constant coefficients is solved as an example. Further, the half-order linear problem with constant coefficients is solved with a method of undetermined coefficients and with a transform method.
Shaping the endoplasmic reticulum into the nuclear envelope

The nuclear envelope (NE), a double membrane enclosing the nucleus of eukaryotic cells, controls the flow of information between the nucleoplasm and the cytoplasm and provides a scaffold for the organization of chromatin and the cytoskeleton. In dividing metazoan cells, the NE breaks down at the onset of mitosis and then reforms around segregated chromosomes to generate the daughter nuclei. Recent data from intact cells and cell-free nuclear assembly systems suggest that the endoplasmic reticulum (ER) is the source of membrane for NE assembly. At the end of mitosis, ER membrane tubules are targeted to chromatin via tubule ends and reorganized into flat nuclear membrane sheets by specific DNA-binding membrane proteins. In contrast to previous models, which proposed vesicle fusion to be the principal mechanism of NE formation, these new studies suggest that the nuclear membrane forms by the chromatin-mediated reshaping of the ER.
Secretion of corticosterone in vitro by normothermic and hibernating ground squirrels

Abstract 1. 1. Evidence is presented for corticosterone as the major adrenal steroid in the ground squirrel ( Citellus ) based on Chromatographic behavior and crystallization data of the free and acetylated product obtained after incubation of 14 C-labeled progesterone. 2. 2. A fluorometric analysis of the adrenal secretions after incubation in vitro demonstrated the expected response to ACTH by normothermic animals. 3. 3. The adrenals of hibernating animals did not respond to any level of ACTH employed.
Volume shifts and protein binding estimates using equilibrium dialysis: Application to prednisolone binding in humans

Sizable volume shifts can occur during equilibrium dialysis. This net movement of water, presumably caused by the osmotic effect of plasma proteins, reduces the concentration of binding proteins. In this paper the theory of protein binding estimation is extended, equations are developed for calculating the unbound and bound drug concentrations at dialysis equilibrium by correcting for the dilution of the proteins, and the equations are applied to a study of prednisolone. To demonstrate the importance of correcting for the volume shift, the parameters of a model in which prednisolone binds to corticosteroid-binding globulin, a protein with a limited capacity, and albumin were estimated. Unbound and bound concentrations were determined by correcting for both volume shifts (average 31%) and loss of drug to the buffer side, by correcting only for loss of drug to buffer side, and by making no correction at all (the usual method of treating equilibrium dialysis data). The error introduced by neglecting volume shifts was analyzed by comparing the parameter values obtained using the three methods. The results confirm the need to adjust for volume shifts and imply that reported binding constants obtained by equilibrium dialysis may be in error for many substances.
Population change and farm dependence: Temporal and spatial variation in the U.S. great plains, 1900–2000

I investigate the relationship between county population change and farm dependence in the Great Plains region during the twentieth century, using spatial data analysis techniques. This research is rooted in a long-standing sociological and demographic interest in population responses to economic transitions and informs the theoretical understanding of urbanization processes. Using census and environmental data, the analysis challenges earlier assertions of a simple transition in the relationship between farm dependence and population change that accompanied modern technological advancements, namely tractors (the mechanization thesis). Rather than observing the proposed positive-to-negative shift, study results show a negative association throughout the pre- and post-mechanization periods. Partial support is found if the thesis is revised to consider the relationship between population change and the change in farm dependence rather than the level of farm dependence. Findings show mixed support for an alternative argument that nonfarm industries moderate the in_ uence of farm dependence (the industry complex thesis). In contrast to earlier applications of the thesis, industrial relations in the Great Plains context are characterized by specialization rather than cooperation.
The role of resources: micro‐firms internationalization in the French context

Purpose – The purpose of this paper is to identify and analyze resources and capabilities that distinguish between traditional, slow born‐global and rapid born‐global micro‐firms.Design/methodology/approach – The study uses multiple case study methodology. Three case studies are presented to compare the internationalization pathways of three French micro‐firms.Findings – The paper emphasizes the importance of leveraging between internal and external resources for rapid internationalization of micro‐firms. The rapid internationalization is driving and facilitated by managerial abilities, innovation and network. The study shows that analysis of micro‐firms in terms of resources and capabilities enhances the understanding of internationalization.Research limitations/implications – Because it is limited to three case studies, the generalization of findings to a broad sample of French micro‐firms will be needed.Practical implications – The research suggests that two‐level analysis (i.e. individual level and mi...
Counterpoint: Access to transcatheter aortic valve replacement should not be limited to high-volume surgical centers.

Transcatheter aortic valve replacement (TAVR) has transformed the treatment of aortic stenosis in high-risk older adults in Europe and has begun to do so in the United States. Recent Food and Drug Administration approval of the Edwards Lifesciences SAPIEN Transcatheter Heart Valve (Irvine, Calif) in inoperable and high-risk patients led to enthusiasm for widespread implementation of this technology. Experts have highlighted the central role of the multidisciplinary heart team in implementing a successful TAVR program.1 Other experts, such as Joseph Bavaria, have suggested that access to TAVR should be restricted to high-volume surgical aortic valve replacement centers. In our opinion, access to TAVR should not be limited to high-volume surgical centers for the following reasons. First, high surgical volume does not ensure good outcomes in complex interventional procedures. Second, centers with low or no surgical volume can have excellent interventional results. Third, new multidisciplinary heart teams have achieved excellent results in part because of the transmission of accumulated knowledge from experienced centers. Finally, in the absence of evidence suggesting that high-volume surgical centers produce superior TAVR results, therapeutic options for patients should not be limited.
Prematurity at birth: trends, racial disparities, and epidemiology.

While infant mortality rates have continued to decline in the U.S., low birth weight and preterm rates have dramatically increased. Although the combination of factors that underlies these trends has not been fully described, there is growing concern that an appreciable part of the rise in prematurity rates stems from efforts taken to improve the survival of these high-risk infants. While advancements in medical technology and practice, augmented by improvements in prenatal care use, may have adversely effected prematurity rates and played a role in broadening racial disparities in pregnancy outcomes, they have positively impacted infant survival. Although many risk factors for prematurity have been identified, there are presently few areas for effective prevention. Accordingly, there is little encouragement for a downturn in prematurity rates in the near future. The prospect of continuing growth in the annual number of surviving preterm infants in the U.S. highlights the need for early detection and treatment of developmental problems for these high-risk survivors, and emphasizes the importance of assuring that needed support services are available to these children and their families. MRDD Research Reviews 2002;8:215–220. © 2002 Wiley-Liss, Inc.
Prehospital care from Napoleon to Mars: the surgeon's role.

g rauma is a surgical disease from beginning to end. Today I’m honored to present the 71 Oration on rauma and the 31st Scudder Oration. This is the oldest uch oration of the American College of Surgeons ACS), established in 1922. I feel humbled, proud, and ucky. Thank you for this distinction. Today we honor our recently departed trauma sureon, educator, advocate for the prehospital provider, nd friend, Scott B Frame, MD, FACS (1952–2000). Charles L Scudder (Fig. 1) was born on August 7, 860 in Kent, CT. He died in 1949. Among his many ccomplishments was being one of the founders of the CS and the first chairman of its Committee on Trauma COT). Dr Scudder himself gave the first Oration on ractures 74 years ago last week, on October 16. No ration was presented during the war years, 1942 to 945. In 1952, the title changed from the Oration on ractures to the Oration on Trauma. Sumner L Koch elivered this lecture, but the subject was still fractures. We usually think of the COT as dating from 1922 ecause this was the year that the first Committee on ractures was appointed at a meeting of the Board of egents in Washington, DC. At the 1912 meeting of he American Surgical Association in Montreal, 1 year efore the formal founding of the ACS, interest in the are of the injured was very low. Too few beds were vailable for those who had sustained injuries to the keletal system and work with such patients was conidered an outpatient endeavor. A visit to the United tates and Canada by Arbuthnot Lane, in 1909, helped ocus on the problem. In 1911, the Presidential Address of he American Surgical Association provided the stimulus or better trauma care. So in Montreal on May 31, 1912,
Aminoglycoside Levels in the Rabbit Vitreous Cavity After Intravenous Administration

Purpose To determine the penetration of gentamicin and amikacin into the rabbit vitreous cavity after their intravenous administration. Methods Gentamicin (1.6 mg/kg every 8 hours) and amikacin (6 mg/kg every 12 hours) were administered intravenously to 25 rabbits that had previously had the lens and vitreous removed from 43 eyes. For each drug, ocular inflammation was induced in one group of eyes by injection of heat-killed Staphylococcus epidermidis , while the other group was maintained as a control. Samples from the vitreous cavity were taken at regular intervals for 72 hours after beginning the intravenous medications and were analyzed for drug concentrations. Results The maximum intravitreal concentration ± SD achieved for gentamicin was 1.8 ± 0.5 μg/ml. The maximum intravitreal concentration for amikacin was 8.5 ±3.2 μg/ml. Inflamed eyes demonstrated higher concentrations than did those without inflammation. Conclusions In a rabbit model with conditions optimized to enhance penetration of antimicrobials into the vitreous cavity after intravenous administration, neither gentamicin nor amikacin penetrated sufficiently to reach potentially therapeutic concentrations consistently for either Pseudomonas or S epidermidis organisms.
Fundamental behavior of electric field enhancements in the gaps between closely spaced nanostructures.

We demonstrate that the electric field enhancement that occurs in a gap between two closely spaced nanostructures, such as metallic nanoparticles, is the result of a transverse electromagnetic waveguide mode. We derive an explicit semi-analytic equation for the enhancement as a function of gap size, which we show has a universal qualitative behavior in that it applies irrespective of the material or geometry of the nanostructures and even in the presence of surface plasmons. Examples of perfect electrically conducting and Ag thin-wire antennas and a dimer of Ag spheres are presented and discussed.
Processing of diagnostic ultrasound signals

Ultrasound signals reflected from the human liver contain significant information about its condition. Several techniques have been developed to process such signals. In this paper, two approaches are described for estimating the slope of the acoustic attenuation coefficient, denoted by β, which provides important cues about the condition of diffuse liver disease. The first is a nonparametric approach which determines the β value from the slope of log periodogram differences. The second is a parametric approach which requires a Gaussian-shaped spectrum and determines the β value from s shift in the spectral center-frequency. A zero-crossing count procedure allows the parametric approach to be implemented with minimal hardware and in real-time. Simulated and actual signals illustrate the two approaches.
Directing mesenchymal stem cells to bone to augment bone formation and increase bone mass

Aging reduces the number of mesenchymal stem cells (MSCs) that can differentiate into osteoblasts in the bone marrow, which leads to impairment of osteogenesis. However, if MSCs could be directed toward osteogenic differentiation, they could be a viable therapeutic option for bone regeneration. We have developed a method to direct MSCs to the bone surface by attaching a synthetic high-affinity and specific peptidomimetic ligand (LLP2A) against integrin α4β1 on the MSC surface to a bisphosphonate (alendronate, Ale) that has a high affinity for bone. LLP2A-Ale induced MSC migration and osteogenic differentiation in vitro. A single intravenous injection of LLP2A-Ale increased trabecular bone formation and bone mass in both xenotransplantation studies and in immunocompetent mice. Additionally, LLP2A-Ale prevented trabecular bone loss after peak bone acquisition was achieved or as a result of estrogen deficiency. These results provide proof of principle that LLP2A-Ale can direct MSCs to the bone to form new bone and increase bone strength.
Ionization of Atoms by Collision with Excited Atoms. II. A Formula without the Rotating-Atom Approximation

A formula for the cross section of the ionization of an atom colliding with an excited atom, A*+B→A+B++e, was obtained. The calculations to the formula were restricted to the case where the transition A→A* is optically allowed and the excitation energy of A* exceeds the ionization potential of B as before. Here all degenerate states of A* and B+e were taken into account. The present formula gives a cross section which is 23% smaller than the previous result calculated by the use of the rotating‐atom approximation. Besides numerical calculations, an approximation method for the basic equations of the present problem is also shown. This method gives the upper and lower bounds of the approximate cross sections obtainable from the basic equations. Other similar calculations were compared with the present results.
Cosupplementation of Dietary Calcium and Conjugated Linoleic Acid (CLA) Improves Bone Mass in Mice

: Conjugated linoleic acid (CLA) has shown a variety of biologically beneficial effects, such as anticancer, antiatherosclerosis, antidiabetic, immunomodulating, and antiobesity effects. Its effects on reduction of body fat occur with enhancement of lean body mass and body ash; the effects of CLA on bone mass are inconsistent in mice and human studies. We hypothesized that the inconsistency of CLA's effect on ash may be linked to interaction between CLA and dietary calcium levels. We reanalyzed our previous studies, which used mice fed 0.5% CLA-containing diet with regular calcium content (0.5%) or enhanced calcium level (0.66%). Extra calcium in the diet improved CLA's effects on bone mass, particularly in male mice (P= 0.0194); without extra dietary calcium there was no effect of CLA on bone mass. This finding may help improve the efficacy of CLA to be used as a dietary supplement to be used as part of an osteoporosis prevention strategy. Further studies are needed to confirm this observation.
Pregnancy complications and outcomes in a cohort of women with epilepsy

To assess the possible adverse effects of maternal epilepsy on the course and outcome of pregnancy, all 138,780 Washington State birth certificates for the years 1980-81 were screened, and 204 births to epileptic mothers were identified. This was a lower than expected frequency of pregnancies in epileptic women. These births were compared with 612 randomly chosen control births for the same 2-year period. Of 46 pre- and perinatal events considered, eight were found to have occurred with significantly increased frequency for mothers with epilepsy. The offspring of these women were 2.8 times more likely to have low birth weight for their gestational age and 2.5 to 3.7 times more likely to have low Apgar scores or asphyxia. The excess risk of these adverse outcomes could not be explained by maternal race, parity, age, previous fetal loss, or socioeconomic status. These findings suggest that increased vigilance for complications of pregnancy and childbirth is warranted for epileptic women.
Time constants for the evolution of sea spray droplets

Sea spray droplets start with the same temperature as the ocean surface from which they form. In high-latitude, polar-low conditions, they therefore cool and evaporate in a relatively cold wind and may alter the air–sea exchange of heat and moisture. This paper presents equations that model the thermal and size (moisture) evolution of a spray droplet from the time it forms until it reaches equilibrium with its environment. The model does well when tested against some of the scanty data available on the evolution of saline droplets. We parameterize the thermal and size evolution of spray droplets with the time constants τ T and τ r , which are, respectively, the times required for a droplet to come to within e -1 of its equilibrium temperature and within e -1 of its equilibrium radius. τ r is always about three orders of magnitude larger than τ T ; the thermal exchange is thus complete before the moisture exchange even starts. Consequently, the ambient humidity has little effect on the thermal exchange rate, and the initial droplet temperature has negligible effect on the moisture exchange rate. We also parameterize the gravitational settling of droplets and their potential for turbulent suspension with the time scales τ f and τ w , respectively. Comparing the four time scales, we see that spray droplets with initial radii less than 10 μ m reach both thermal and size equilibrium with the ambient air. Droplets with initial radii greater than 300 μ m, on the other hand, fall back into the sea before exchanging appreciable heat or moisture; they thus have little impact on air–sea exchange. In the mid-range, droplets with initial radii between 10 and 300 μ m, the physics is more complex. Even after comparing τ T and τ r with τ f and τ w , we still cannot say unequivocally which process is fastest because of the rudimentary nature of the τ w estimates. Future work must thus focus on the generation and turbulent transport of droplets of this size if we are to understand how sea spray affects air–sea exchange. DOI: 10.1034/j.1600-0889.1990.t01-3-00007.x
Apparatus for High-Resolution Birefringence Measurement in Liquid Crystals

Abstract A rotating-analyzer technique for measuring the optical birefringence in liquid crystals is described. This apparatus is continuously readable and has excellent sensitivity. For a sample 50 μm thick, the apparatus has a resolution in the change of birefringence of 4 × 10−6, corresponding to a temperature change of 1 mK in the sample tested.
The Role of Anaerobes in Patients With Ventilator-associated Pneumonia and Aspiration Pneumonia : A Prospective Study

Context Aspiration of oropharyngeal material, with its high concentration of anaerobic bacteria, has been implicated in the pathogenesis of both ventilator-associated pneumonia (VAP) and aspiration pneumonitis (AP). Consequently, patients with these disorders are usually treated with antimicrobial agents with anaerobic activity. Objective To determine the incidence of anaerobic bacteria in patients with VAP and AP. Design Prospective, nonrandomized, interventional study. Setting University-affiliated community teaching hospital. Patients and interventions We performed sequential blind protected specimen brush (PSB) sampling and mini-BAL in 143 patients with 185 episodes of suspected VAP and 25 patients with AP who required mechanical ventilation. Quantitative aerobic and anaerobic cultures were performed on all specimens. Pneumonia was considered to be present when either > 500 cfu/mL cultured from blind PSB sampling or > 5,000 cfu/mL cultured from mini-BAL were present. Results Using the predefined criteria, bacterial pneumonia was diagnosed in 63 of 185 suspected VAP episodes (34%) and 12 of 25 patients with AP (48%). At least one dose of an antibiotic was given in the 24 h prior to bacteriologic sampling in 106 suspected VAP episodes (57%) and in 12 patients with AP (48%). More than one pathogen was isolated from 11 VAP and four AP patients. Pseudomonas aeruginosa , Staphylococcus aureus , and enteric Gram-negative organisms were isolated most frequently from patients with VAP. In the patients with AP, enteric Gram-negative organisms were isolated in patients with GI disorders and Streptococcus pneumoniae and Haemophilus influenzae predominated in patients with“ community-acquired” aspiration. Only one anaerobic organism was isolated from the entire group of patients; Veillonella paravula was isolated from a blind PSB specimen in a patient with suspected aspiration pneumonia. Conclusion Despite painstaking effort, we were able to isolate only one anaerobic organism (nonpathogenic) from this group of patients. The spectrum of aerobes in patients with VAP was similar to that reported in the literature. The organisms found in patients with AP was a reflection of the organisms likely to colonize the oropharynx. The use of antibiotics with anaerobic coverage may not be necessary in patients with suspected VAP and AP. Furthermore, penicillin G and clindamycin may not be the antibiotics of choice in patients with AP.
Microleakage at Gingival Dentin Margins of Class V Composite Restorations Lined with Light-Cured Glass Ionomer Cement

This study compared the microleakage of light-cured and auto-set glass ionomer liners used in Class V composite laminated glass ionomer restorations by determining the amount of microleakage at the gingival cementum/dentin margins. Standardized nonundercut V-shaped Class V cavities with gingival margins below the cementoenamel junction were prepared on the mesial and distal surfaces of 40 molars, establishing a total of 80 cavities, which were randomly divided into four groups. Each was lined with glass ionomers: group 1, Ketac-Bond (ESPE-Premier), which served as the control; group 2, XR-Ionomer (Kerr); group 3, XR-Ionomer with polyacrylic acid (PAA) pretreatment (Kerr); and group 4, Vitrabond (3M). Specimens were thermotycled for 300 cycles in 0.5% aqueous solution of basic fuchsin between 4 and 55 C with a 1-minute dwell time, and individually embedded in an epoxy resin. Statistical analysis indicated no differences among groups using the light-cured glass ionomer (groups 2 to 4), and they showed significantly less leakage than the control (group 1) at P