cssi/SciSciGPT-SciSciNet huggingface dataset:
Trace Elements as Possible Environmental Indicators in Carbonate Rocks: ABSTRACT

Carbonate sediments are composed chiefly of biogenic fragments. The biogeochemistry of the shells or skeletons of organisms contributing to the sediments reflects some of the variables in the chemistry of the water in which they lived. An important factor determining the composition of the trace-element biogeochemistry of the shells appears to be the availability of certain trace elements in the waters in which the organisms lived. The trace-element composition of fresh water differs from that of sea water. Three elements particularly showing differences in concentration between fresh and marine water are barium, iron, and manganese. The average amount of barium in marine water is about 0.05 ppm.; in fresh water the barium content may exceed that of marine water, be less, or be approximately the same. The average iron content in marine water is about 0.008 ppm. in contrast to 1.0 ppm. for river water. The average manganese content of marine water is about 0.003 ppm. and of river water is near 0.03 ppm. Lagoonal waters contain more iron and manganese for uptake by organisms than do waters of an open-marine environment. A study of marine, lagoonal, and fresh-water gastropods and pelecypods shows that the shells of non-marine and lagoonal mollusks contain a greater abundance of barium, iron, and manganese than do those of marine mollusks. The difference between marine and non-marine is independent of taxonomic rank or mineralogy of the shells. Modern molluscan shells as well as Recent carbonate sediments from Florida show, as a rule, a greater abundance of iron and manganese than do those from a marine environment. Scatter plots of one against the other of these three trace elements, despite some overlap, show groupings which correlate with environment. Could trace elements become a prospective tool in environmental recognition? Perhaps they could under some special circumstances. The problem is that, during diagenesis, the mineralogy and chemistry of carbonate sediments, including the trace element assemblage, are drastically changed. End_of_Article - Last_Page 464------------
Factors associated with psychological distress in cancer patients

We studied the mental health of 1,278 patients with cancer and 645 family members of patients with cancer to delineate clinical and demographic characteristics associated with poor psychological status. For both patients and their matched relatives, there was a direct relationship between poorer mental health scores and younger age. Highly significant age differences emerged as well for subscale scores of anxiety, depression, and general positive affect in patients, and for depression, emotional ties, and loss of control in relatives. Treatment status, performance status, and sex also contributed significantly to mental health scores. Patients at greatest risk for psychological problems are young, female, receiving palliative or active treatment as opposed to follow-up care, and symptomatic or not fully ambulatory. Clinicians should be alert to the potential for psychological problems among patients in these categories.
Deposition of polymer coatings onto SAW resonators using AC electrospray

Polymers were deposited onto the surface of surface acoustic wave (SAW) resonators using AC electrospray. The film quality and resulting device performance was investigated and compared to similar devices coated using DC electrospray, airbrush and the method known as rapid expansion of supercritical solutions (RESS). It was demonstrated that the AC electrospray method is capable of producing coatings with much higher quality than both DC electrospray and airbrush methods and of comparable quality to the coatings produced using RESS. The simplicity of the AC electrospray polymer deposition method makes it particularly attractive for the deposition of nanoscale polymer films onto microelectrodes.
Charge trapping in poly(1-amino-anthraquinone) films

Abstract Poly(1-amino-anthraquinone) films prepared by electrochemical polymerization of 1-amino-9,10-anthraquinone in 6 M H 2 SO 4 (aq) have been studied by cyclic voltammetry and impedance spectroscopy in 6 M H 2 SO 4 (aq) in order to understand kinetic limitations on the quinone electrochemistry. Reduction of the quinone groups was found to occur rapidly close to the formal potential of ca. −0.1 V vs. SCE, while the reoxidation peak was shifted to much higher potentials (≥+0.36 V), even at 5 mV s −1 . This trapping of the quinone in its reduced state can be explained by an increase in the resistance of the film as the poly-aniline backbone is reduced.
Reptation in polymer blends

Forward recoil spectrometry (FRES) was used to measure the tracer diffusion coefficients D∗PS and D∗PXE of deuterated polystyrene (d-PS) and deuterated poly(xylenyl ether) (d-PXE) chains in high molecular weight protonated blends of these polymers. The D∗s were shown to be independent of matrix molecular weights and to decrease as M−2, where M is the tracer molecular weight, suggesting that the tracer diffusion of both species occurs by reptation. These D∗s were used to determine the monomeric friction coefficients ζ0,PS and ζ0,PXE of the individual PS and PXE macromolecules as a function of ф, the volume fraction of PS in the PS:PXE blend. Since ζ0,PS⪡ζ0,PXE at each ф, the rate at which a PS molecule reptates is much greater than that of a PXE molecule, even though both chains are diffusing in identical surroundings. Part of this difference may be due to the difficulty of backbone bond rotation of the PXE molecule. However, even when measured at a constant temperature increment above the glass transition temperature, ζ0,PS and ζ0,PXE were observed to be markedly composition dependent. In addition the ratio ζ0,PSζ0,PXE varied from a maximum of 4 × 10−2 near ф=0.85 to a minimum of 5 × 10−5 for ф=0.0. These results show that intramolecular barriers do not solely determine the ζ0s of the components in this blend. Clearly, the interactions between the diffusing chains and the matrix chains also influence ζ0.
The algebra for formal series. II. Sheffer sequences

In this paper we continue the study of the algebra of formal series. We will develop some new results on special sequences and begin the study of Sheffer Sequences, discussing the important examples of Hermite, Laguerre and Bernoulli. The second section gives a very brief survey of parts of [I] as well as a new result which will be used in the sequel. A general remark about the theory is in order. Sequences of polynomials of binomial and Sheffer type-such as those of Hermite, Laguerre and Bernoulli-have played a key role in the theory of special functions. It is the yoga of the algebra of formal series that these sequences are but the polynomial tip of corresponding sequences of Laurent series with a finite number of terms of positive degree. By corresponding we mean that the sequences of Laurent series possess many of the same algebraic properties as the sequences of polynomials To be absolutely plain, to each sequence of polynomials of Sheffer type (which includes binomial type)
Efficacy of chlorine dioxide gas and freezing rate on the microbiological quality of frozen blueberries

Abstract Blueberries are prone to microbial contamination, with growth of bacteria, yeasts and molds during bulk freezing negatively impacting quality and marketability. As a follow-up to our previous work, the combined impact of ClO2 gassing and freezing rate on the microbiological quality of frozen blueberries was examined. Sixteen lugs of blueberries (∼9.1 kg/lug) were stacked inside a large plastic container at a commercial blueberry processing facility. In each of four trials, one container was exposed to ClO2 gas (4 ppm) using three 3-kg sachets while one ungassed container remained untarped. Before and after commercial processing, 50-g samples of gassed and ungassed blueberries were quantitatively examined for mesophilic aerobic bacteria (MAB), yeasts, and molds. After processing, additional 50-g samples were placed in a −20 °C freezer under different conditions where the berries reached a temperature of −3 °C after 3 h (quick-frozen), 2 days (intermediate-frozen) and 5 days (slow-frozen). Fruit was sampled periodically during 6 months of frozen storage at −20 °C. MAB yeast and mold populations decreased ∼2 and 1 log CFU/g, respectively, in ClO2-gassed and ungassed fruit, with MAB, yeast and mold populations increasing ∼1 log CFU/g during quick freezing to −3 °C and ∼2 log CFU/g during intermediate and slow freezing to −3 °C. Based on these findings, ClO2 gassing followed by quick freezing provides an effective means for meeting the current microbiological standards being imposed by buyers of frozen blueberries.
Influence of Alpha-Tocopherol upon Development of Cardiovascular Necrosis and Hypertension in the Rat.

Summary1. Disseminated muscular necrosis following experimental nephropathy in albino rats maintained on complete rations, was not beneficially influenced by the presence of excessive amounts of alpha-tocopherol. On the contrary, this drug appeared responsible for a higher incidence of advanced lesions in the aorta, coronary arteries, and stomach. 2. Concomitant renal hypertension was not alleviated by the presence of alpha-tocopherol in excess. In normotensive rats large dosages of this compound may induce moderate hypertension.
A mechanism for substrate-Induced formation of 6-hydroxyflavin mononucleotide catalyzed by C30A trimethylamine dehydrogenase.

Abstract Experiments are described to determine the origin of the 6-hydroxyl group of 6-hydroxyFMN produced by the substrate-induced transformation of FMN in the C30A mutant of trimethylamine dehydrogenase. The conversion of FMN to 6-hydroxyFMN is carried out in the presence of H218O and 18O2, and the results clearly show that the 6-hydroxyl group is derived from molecular oxygen and not from water.
Inhibition of replicon cluster ligation into chromosomal DNA at elevated temperatures.

The rate limiting enzymatic step for DNA replication in HeLa cells incubated at 43.5°C v/as the ligation of clusters of replicons into the cell's genome. At 43.5° the reciprocal slope for inhibition of DNA chain (replicon) initiation, or of the ligation of replicon clusters into the genome, was 18 or 7 min, respectively. The failure of replicon clusters to be ligated into chromosomal DNA was not a consequence of the failure of histone proteins to be deposited onto replicating DNA, or of chromatin replicated at 43.5°C to be organized into fully condensed chro-matin. In addition it was not due to the failure of fully active topoisomerase II to be deposited at a normal frequency along replicating chromatin DNA. The failure of replicon clusters to be ligated into the genome resulted in the persistence of single, but not double, DNA strand breaks in the cell's genome 24 hours after cell heating.
Configuring graphics systems components

Computer graphics systems have traditionally been described in terms of a conceptual model of the so-called ‘graphics processing pipeline’. This model explains the relationship between graphics information defined by an application and the realisation of that information on a display in terms of a sequence of transformation stages. Although adequate for giving an outline of a single graphics system, the model lacks flexibility and detail when placed in the sphere of many different graphics systems designs, as in the ‘family of graphics systems’ under ISO standardisation at the current time. An alternative approach is needed which provides a sufficient level of detail and flexibility to describe both existing graphics systems and possible extensions to these, which at the same time permits the comparison of graphics systems designs in a well defined framework. The computer graphics reference model presented in this paper meets many of these objectives.
Abstract 3212: Development of a chemiluminescence-based single telomere length analysis (STELA) method

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Carcinogenesis is a multistep process characterized by the accumulation of genetic alterations that drive the transformation of normal cells to malignant cells. Telomeres are specialized nucleoprotein structures that function to protect and stabilize the ends of eukaryotic chromosomes by preventing chromosome fusions, masking double strand DNA break damage signals and preventing exonucleolytic chromosomal degradation. It is well established that telomere shortening is present in precursor and invasive stages of many carcinomas. Additionally, numerous investigations have demonstrated that altered telomere length predisposes cells to possess the properties necessary for metastasis formation, and therefore represents a predictor of clinical outcome. However, most of these studies have used assays that measure the average telomere length of all the cells in a particular population. To circumvent this problem, Baird et al. (Nature Genetics, 2003) previously described a PCR-based single telomere length analysis (STELA) method that could accurately measure the full spectrum of telomere lengths from a specific chromosomal arm. Although this method represents a substantial improvement over existing methods, the assay requires the use of radioactive material. Here, we describe a modification of the STELA assay which uses chemiluminescence instead of radioisotopes for product visualization, while maintaining the overall sensitivity of the detection of a wide range of telomere lengths. This new methodology has tremendous potential to illuminate the mechanisms that support the initiation of cancer and may provide an avenue for investigators to address the full extent and significance of telomere shortening in the tumorigenic process at the single chromosome level. The modified assay described here will allow for more widespread use of this technique among cancer researchers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3212.
Possibility of new effects in quantum wells coupled by Coulomb interaction

Abstract The hamiltonian for two 2-dimensional layers of electrons (neglecting spin), is similar to that of a free electron gas with the role of spin-up and spin-down electrons being played by electrons in two layers. An anomalous ground state analogous to the spiral spin density wave (SSDW) state presents intriguing possibilities.
Rac1, a low‐molecular‐mass GTP‐binding‐protein with high intrinsic GTPase activity and distinct biochemical properties

Rac1, a member of the family of low-molecular-mass GTP-binding proteins, functions in phagocytic leukocytes as a component necessary for activation of the respiratory burst. To characterize the biochemical properties of rac1, the protein was expressed as a fusion protein in Escherichia coli and purified to greater than 99% homogeneity by affinity chromatography. Rac1 protein bound maximally bound and hydrolyzed GTP under low free-Mg2+ concentrations. Under those conditions, (45 nm free Mg2+), purified rac1 exhibited a steady-state GTPase activity of 18 nmol.min-1.mg protein-1 (turnover number approximately 0.39 min-1 at 37 degrees C), which is 40-fold higher than H-ras. The high intrinsic GTPase activity of rac1 under low free Mg2+ was mainly due to an increased kcat, the rate constant for hydrolysis of bound GTP, which was 0.29 min-1 for rac1 vs 0.007 min-1 for H-ras (at 20 degrees C). Rac1 also released bound GDP faster than H-ras (koff.GDP = 1.02 min-1 for rac1 vs 0.33 min-1 for H-ras at 20 degrees C). In contrast, rac1 released bound guanosine 5'-[gamma-thio]triphosphate (GTP[S]) at a slower rate than H-ras (koff.GTP[S] approximately 0.04 min-1 for rac1 vs 0.31 min-1 for H-ras at 20 degrees C). Rac1 was a very good substrate for in vitro geranylgeranylation (C20) but not for farnesylation (C15), whereas the converse is true for H-ras. Surprisingly, rac1 was a very poor substrate for in vitro ADP-ribosylation by the C3 component of Clostridium botulinum toxin compared to rhoA. As a further characterization of rac1, a mutant was made in which the Thr115 was replaced by asparagine. This protein (referred to as [Thr115----Asn]rac1) contains the consensus amino acids of all four GTP-binding domains of H-ras. The koff.GDP of [Thr115----Asn]rac1 was reduced to that of H-ras, but [Thr115----Asn]rac1 exhibited essentially identical kcat (0.13 min-1 at 20 degrees C) and koff-GTP[S] (0.03 min-1 at 20 degrees C) values as the wild-type protein. Thus, the region(s) in rac1 which control the dissociation of GTP[S] (and presumably GTP) do not entirely coincide with those controlling GDP dissociation. Biochemical analysis of [Thr115----Asn]rac1 also suggests that the region responsible for the increased kcat of rac1 is not within the consensus amino acids of the four guanine-nucleotide-binding domains.
Single-disk cams with positively controlled oscilating followers

Abstract Single-disk cams that positively operate reciprocating followers are extensively used. With oscillating followers two-disk cams are conventionally used because of the inherent disadvantages of a single-disk arrangement. Novel methods are described whereby disadvantages can be overcome, permitting greatly expanded use of the single-disk form with oscillating followers and also for cam-operated linkages thus providing a new group of cam-operated mechanisms for design purposes. Design parameters are presented and the manner is described in which computer programs were prepared for performing the desired computations.
Visual input to rat pineal

Electrophysiological recordings from freely behaving rats, previously implanted stereotaxically with permanent electrodes in the pineal, ventromedial hypothalamus, caudate nucleus, lateral geniculate body and medial geniculate body were obtained. The pineal photic responses revealed 5 sequential components. Injection of a neuronal blocker at the level of the superior cervical ganglion did not alter the earlier photic responses, but did eliminate the late components (N2−P3) for 60–90 min after the injection. All of the other responses were unchanged during the experiment. The present experiments demonstrated that photic input travels to the pineal through two pathways.
The Limits of the Preponderance of the Evidence Standard: Justifiably Naked Statistical Evidence and Multiple Causation

The preponderance-of-the-evidence standard usually is understood to mean that the plaintiff must show that the probability that the defendant is in fact liable exceeds 1/2. Several commentators and at least one court have suggested that in some situations it may be preferable to make each defendant pay plaintiff's damages discounted by the probability that the defendant in question is in fact liable. This article analyzes these and other decision rules from the standpoint of statistical decision theory. It argues that in most cases involving only one potential defendant, the conventional interpretation of the preponderance standard is appropriate, but it notes an important exception. The article also considers cases involving many defendants, only one of whom could have caused the injury to plaintiff. It argues that ordinarily the single defendant most likely to have been responsible should be liable for all the damages, even when the probability associated with this defendant is less than 1/2. At the same time, it identifies certain multiple-defendant cases in which the rule that weights each defendant's damages by the probability of that defendant's liability should apply.
MR imaging of pancreas in cystic fibrosis

The pancreatic regions of 18 patients with cystic fibrosis were analyzed with a 1.5 Tesla MR unit. Signal intensity of the pancreas was correlated with clinical data and ultrasound. A hyperintense pancreas on T1-weighted image was consistent with fatty replacement of pancreatic patient. A very hypointense pancreas on any pulse sequence was considered to be an intermediate stage of pancreatic degeneration.
Impact of Commercialization of the Internet on International Trade: A Panel Study Using the Extended Gravity Model

This article tests the proposition that information and communication technology (ICT) and the Internet have enhanced international trade. Until recently, a sufficiently lengthy series of data as not available to make valid comparisons of international trade before and after the commercialization of the Internet. The use of balanced panel data for 64 countries (representing many phases of economic development) for the years 1985 to 2005 and the instrumental variable approach of Hausman and Taylor and other panel data methods provide an adequate basis for our conclusions. The results of the study are unequivocal and robust. There is a positive and significant effect of ICT infrastructure and the availability of the Internet for commercial transactions on the volume of international trade.
Pulmonary valvuloplasty in adults using the Inoue balloon catheter.

This report describes a new balloon pulmonary valvuloplasty technique using the Inoue balloon catheter performed in 14 consecutive adult patients, aged 17–47 years (mean 27). The mean right ventricular systolic pressure and the pulmonary valvular peak-to-peak systolic gradient decreased from 102 ± 41 to 52 ± 19 mm Hg (p = 0.001) and 81 ± 40 to 7 ± 7 mm Hg (p = 0.0002), respectively. An infundibular peak-to-peak systolic gradient either developed (n = 13) or increased (n = 1). None of the patients were treated with beta-adrenergic blockers before or after the valvuloplasty. Eight patients underwent repeat hemodynamic study 12–30 months (mean 17) after treatment, and had no evidence of valvular restenosis. The mean right ventricular systolic pressure and the mean infundibular peak-to-peak systolic gradient decreased, compared to the values immediately after valvuloplasty (54 to 40 mm Hg, p = 0.03, and 28 to 10 mm Hg, p = 0.03, respectively). The study suggests that pulmonary valvuloplasty in adults using the Inoue balloon catheter technique is feasible, safe, and effective. © 1993 Wiley-Liss, Inc.
Intercontinental transport of tropospheric ozone: a study of its seasonal variability across the North Atlantic utilizing tropospheric ozone residuals and its relationship to the North Atlantic Oscillation

Abstract. Using the empirically-corrected tropospheric ozone residual (TOR) technique, which utilizes coincident observations of total ozone from the Total Ozone Mapping Spectrometer (TOMS) and stratospheric ozone profiles from the Solar Backscattered Ultraviolet (SBUV) instruments, the seasonal and regional distribution of tropospheric ozone across the North Atlantic from 1979-2000 is examined. Its relationship to the North Atlantic Oscillation (NAO) is also analyzed as a possible transport mechanism across the North Atlantic. Monthly climatologies of tropospheric ozone for five different regions across the North Atlantic exhibit strong seasonality. The correlation between these monthly climatologies of the TOR and ozonesonde profiles at nearby sites in both eastern North America and western Europe are highly significant (R values of +0.98 and +0.96 respectively) and help to validate the use of satellite retrievals of tropospheric ozone. Distinct springtime interannual variability over North Atlantic Region 5 (eastern North Atlantic-western Europe) is particularly evident and exhibits similar variability to the positive phase of the NAO (R=+0.61, r =
Household Decision Making and Evacuation in Response to Hurricane Lili

This study collected data on the evacuation from Hurricane Lili to answer questions about households' reliance on information sources, the factors affecting their decisions to evacuate, the timing of their hurricane evacuation decisions, and the time it took them to prepare to evacuate. The results replicated previous findings on the sources of hazard information, evacuation concerns, and the timing of evacuation decisions. In addition, they provide new information about evacuation preparation times and the finding that household characteristics are uncorrelated with evacuation decision times or evacuation preparation times.
Depletion of intrinsic expression of Interleukin-8 in prostate cancer cells causes cell cycle arrest, spontaneous apoptosis and increases the efficacy of chemotherapeutic drugs

Background The progression of all cancers is characterized by increased-cell proliferation and decreased-apoptosis. The androgen-independent prostate cancer (AIPC) is the terminal stage of the disease. Many chemokines and cytokines are suspects to cause this increased tumor cell survival that ultimately leads to resistance to therapy and demise of the host. The AIPC cells, but not androgen-responsive cells, constitutively express abundant amount of the pro-inflammatory chemokine, Interleukin-8 (IL-8). The mechanism of IL-8 mediated survival and therapeutic resistance in AIPC cells is unclear at present. The purpose of this report is to show the pervasive role of IL-8 in malignant progression of androgen-independent prostate cancer (AIPC) and to provide a potential new therapeutic avenue, using RNA interference.
Motion-aware self-localization for underwater networks

A myriad of ocean processes affect life on the planet and are a source of intrigue to oceanographers and scientists. Understanding these processes and their interactions with currents requires collection of relevant data. A network of mobile platforms can be used to learn the correlation of processes in space and over time. To do this, data samples collected by nodes have to be annotated with location information. Given limited access to Global Positioning Systems underwater, collaborative self-localization schemes applied periodically are well-suited for this purpose. However, the specific nature of the underwater acoustic environment introduces significant error during network self-localization due to the combined effect of large latencies in communication and node mobility. We propose a method to account for these effects thus significantly improving the accuracy of position estimates.
Telomere biology: Cancer firewall or aging clock?

It has been a decade since the first surprising discovery that longer telomeres in humans are statistically associated with longer life expectancies. Since then, it has been firmly established that telomere shortening imposes an individual fitness cost in a number of mammalian species, including humans. But telomere shortening is easily avoided by application of telomerase, an enzyme which is coded into nearly every eukaryotic genome, but whose expression is suppressed most of the time. This raises the question how the sequestration of telomerase might have evolved. The predominant assumption is that in higher organisms, shortening telomeres provide a firewall against tumor growth. A more straightforward interpretation is that telomere attrition provides an aging clock, reliably programming lifespans. The latter hypothesis is routinely rejected by most biologists because the benefit of programmed lifespan applies only to the community, and in fact the individual pays a substantial fitness cost. There is a long-standing skepticism that the concept of fitness can be applied on a communal level, and of group selection in general. But the cancer hypothesis is problematic as well. Animal studies indicate that there is a net fitness cost in sequestration of telomerase, even when cancer risk is lowered. The hypothesis of protection against cancer has never been tested in animals that actually limit telomerase expression, but only in mice, whose lifespans are not telomerase-limited. And human medical evidence suggests a net aggravation of cancer risk from the sequestration of telomerase, because cells with short telomeres are at high risk of neoplastic transformation, and they also secrete cytokines that exacerbate inflammation globally. The aging clock hypothesis fits well with what is known about ancestral origins of telomerase sequestration, and the prejudices concerning group selection are without merit. If telomeres are an aging clock, then telomerase makes an attractive target for medical technologies that seek to expand the human life- and health-spans.
Voice command recognition system for handicapped persons using simple multi-layered networks

A portable voice command recognition system for a specific speaker using a multilayered network has been developed to reliably recognize up to 16 commands. The intended application is the control of various program modes of a multichannel muscle stimulator. The voice input system consists of microphone and a detector which produces a pulse for each zero-crossing of the filtered microphone voltage. A microprocessor transforms these pulses into an array of 32 zero-crossing frequencies. These data were used for conventional pattern matching as well as for several network methods of word recognition. The recognition accuracy was tested by pronouncing each of 16 command words 50 times and measuring how often the computer responded with the correct answer. The pattern-matching method achieved an accuracy of 88%. The network method, with two layers and 15 repetitions during the training period, achieved an accuracy of 92%. A four-layered network produced an accuracy of 97%. >
Experimental Support of the Scaling Rule for Demographic Stochasticity

A scaling rule of ecological theory, accepted but lacking experimental confirmation, is that the magnitude of fluctuations in population densities due to demographic stochasticity scales inversely with the square root of population numbers. This supposition is based on analyses of models exhibiting exponential growth or stable equilibria. Using two quantitative measures, we extend the scaling rule to situations in which population densities fluctuate due to nonlinear deterministic dynamics. These measures are applied to populations of the flour beetle Tribolium castaneum that display chaotic dynamics in both 20-g and 60-g habitats. Populations cultured in the larger habitat exhibit a clarification of the deterministic dynamics, which follows the inverse square root rule. Lattice effects, a deterministic phenomenon caused by the discrete nature of individuals, can cause deviations from the scaling rule when population numbers are small. The scaling rule is robust to the probability distribution used to model demographic variation among individuals.
Nonlinear mixing in surface-micromachined tuning fork oscillators

This paper discusses the conversion of voltage to frequency in surface-micromachined tuning fork oscillators intended as resonant transducers. First, the sources of nonlinearity in the mechanical structure and electrostatic actuation are discussed. These nonlinearities are analytically combined to show that low-frequency voltage drift in the sustaining amplifier is directly converted into a frequency shift in the oscillator output. Experimental evidence of this effect is presented, and it is shown that this is the dominant source of near-carrier frequency instability in the experimental system.
Upper Echelons Research Revisited: Antecedents, Elements, and Consequences of Top Management Team Composition:

This study reviews recent research building on Hambrick and Mason’s [Hambrick, D. C., & Mason, P. A. (1984). Upper echelons: The organization as a reflection of its top managers. Academy of Management Review, 9: 193–206] upper echelons (UE) perspective with the aim of identifying challenges and opportunities for future UE-based organizations research. Our review highlights a number of central facets of the UE perspective: It is at once a theoretical framework predicting that organizations will be a reflection of their top management teams and a methodology that relies on executive demography as a measurement proxy for underlying individual and group cognitions and behaviors. In proposing new research directions, we challenge organizations researchers to (1) reconsider the universality of the top management team (TMT) construct, (2) carefully explore the practical and theoretical meaning of TMT demographic characteristics vis-a-vis the deeper constructs they are presumed to proxy, (3) integrate other deter...
Breaking the Bottleneck in the Protein Biomarker Pipeline

The process for discovery and development of biomarkers of solid tumors presents exceptional challenges. The major technical obstacle is the disconnection between the site of their generation (tissue, proximal fluid) and the source of detection (body fluids, predominantly serum and plasma). This single factor limits, in practical terms, the potential pool of biomarkers to those that are secreted, shed, or leaked from the cell surface. On reaching the circulation, a biomarker undergoes “dilution” into a mixture of thousands of proteins that are present at concentrations spanning at least 10 orders of magnitude. Furthermore, the integrity of a circulating biomarker may be compromised by proteolytic degradation or distortion of its posttranslational modifications. Other levels of complexity involve the inherent variability of biological systems (intraindividual and across a population) and ambiguities in defining disease phenotypes. Finally, fundamental and technological difficulties involved in biomarker studies are exacerbated by preanalytical variables associated with sample collection, handling, and storage (1, 2). An ideal cancer biomarker would be detectable in body fluids at an early stage of disease in a highly specific and selective fashion and be measurable for an inexpensive price. Development of such a biomarker is not a trivial endeavor. To promote efficiency and rigor in cancer biomarker research, Pepe et al. (3) introduced guidelines for a generally appropriate process that could be applied to many other diseases and classes of biomarker (e.g., a protein or a metabolite). These guidelines propose specific aims and measures of success for each of the 5 phases of a biomarker discovery pipeline in the context of progress being made in the field and relevant published studies. It is now evident that the majority of proteomics and genomics studies published to date do not progress far beyond the discovery stage (phase 1), because the development of clinical …
Asymptomatic Aortic Stenosis in the Elderly: A Clinical Review

Importance Aortic stenosis is the most common form of valvular heart disease. Progression of aortic stenosis is very slow and highly variable. Decisions about when to perform valve surgery are made by subjective assessment of patient symptoms and objective measures of the valve and ventricular function by transthoracic echocardiography. Objective To review current concepts regarding the development, progression, and assessment of aortic stenosis; the appropriate monitoring intervals for transthoracic echocardiography; and the indications for valve procedures. Evidence Review Guidelines and literature search. Findings Angina, exertional syncope, and heart failure are key symptoms indicating a need for intervention. The frequency of valvular monitoring by transthoracic echocardiography is guided by the disease severity. Despite evidence of severe disease, valve procedures can safely be deferred if patients experience no symptoms and have normal left ventricular ejection fraction. Asymptomatic patients with severe aortic stenosis may subconsciously curtail their activities to avoid symptoms. Apparently, asymptomatic patients can undergo a carefully monitored exercise stress test to confirm both their asymptomatic status and hemodynamic response to exercise. Bioprosthetic valves are a good replacement alternative for older patients who are good surgical candidates and who have no need for warfarin therapy. For patients who are at high or very high risk of cardiac surgery, transcutaneous aortic valve implantation is an increasing available and preferred over medical management. Conclusions and Relevance Asymptomatic patients with severe aortic stenosis require frequent monitoring of their subjective symptoms combined with objective measurement of aortic valve gradient and ventricular function by transthoracic echocardiography. Although conventional surgical replacement remains the mainstay of therapy for aortic stenosis, transcutaneous aortic valve implantation options are evolving.
Frustrated Solvation Structures Can Enhance Electron Transfer Rates

Polar surfaces can interact strongly with nearby water molecules, leading to the formation of highly ordered interfacial hydration structures. This ordering can lead to frustration in the hydrogen bond network, and, in the presence of solutes, frustrated hydration structures. We study frustration in the hydration of cations when confined between sheets of the water oxidation catalyst manganese dioxide. Frustrated hydration structures are shown to have profound effects on ion-surface electron transfer through the enhancement of energy gap fluctuations beyond those expected from Marcus theory. These fluctuations are accompanied by a concomitant increase in the electron transfer rate in Marcus's normal regime. We demonstrate the generality of this phenomenon-enhancement of energy gap fluctuations due to frustration-by introducing a charge frustrated XY model, likening the hydration structure of confined cations to topological defects. Our findings shed light on recent experiments suggesting that water oxidation rates depend on the cation charge and Mn-oxidation state in these layered transition metal oxide materials.
Breast and cervical cancer screening among Asian subgroups in the USA: estimates from the National Health Interview Survey, 2008, 2010, and 2013

This study describes variations in mammography and Pap test use across and within subgroups of Asian women in the USA. Using data from the National Health Interview Survey (2008, 2010, and 2013), we calculated weighted proportions for selected Asian subgroups (Asian Indian, Chinese, Filipino, Other Asian) of women reporting mammography and Pap test use. The proportion of women aged 50–74 years who reported a mammogram within the past 2 years did not differ significantly across Asian subgroups. The proportion of women aged 21–65 years who received a Pap test within the past 3 years differed significantly across Asian subgroups, with lower proportions among Asian Indian, Chinese, and Other Asian women. Recent immigrants, those without a usual source of care, and women with public or no health insurance had lower proportions of breast and cervical cancer screening test use. Patterns of mammography and Pap test use vary among subgroups of Asian women, by length of residency in the USA, insurance status, usual source of care, and type of cancer screening test. These findings highlight certain Asian subgroups continue to face significant barriers to cancer screening test use.
Chordomas of the skull base: MR features.

PURPOSE To characterize the MR features of skull base chordomas with regard to signal intensity, size, position, extension, and Gd-DTPA enhancement. PATIENTS AND METHODS The MR imaging studies of 28 patients with surgically proven chordomas of the skull base were retrospectively reviewed. Twenty-two of these patients received intravenous administration of Gd-DTPA. RESULTS On short TR/short TE images, chordomas generally had low to intermediate signal. On long TR/long TE images, chordomas generally had very high signal that was heterogeneous in 79%. After Gd-DTPA administration, all chordomas demonstrated some degree of contrast enhancement. In most cases, enhancement was demonstrated throughout most of each tumor in a heterogeneous pattern. Chordomas were associated with MR findings of displacement and encasement of vessels, and frequent extension into adjacent structures such as the cavernous sinus, sella, nasopharynx, and hypoglossal canal. CONCLUSION The MR characterization of the position and extent of these neoplasms played an important role in determining the optimal surgical approaches for gross total tumor resection.
Chaos, creativity, and substance abuse: the nonlinear dynamics of choice

Artists create their work in conditions of disequilibrium, states of creative chaos that may appear turbulent but are capable of bringing forth new order. By absorbing information from the environment and discharging it negentropically as new work, artists can be modeled as dissipative systems. A characteristic of chaotic systems is a heightened sensitivity to stimuli, which can generate either positive experiences or negative ones that can lead some artists to substance abuse and misguided searches for a creative chaos. Alcohol and drug use along with inadequately addressed co-occurring emotional disorders interfere with artists' quest for the nonlinearity of creativity. Instead, metaphorically modeled by a limit cycle of addiction and then a spiral to disorder, the joys of a creative chaos become an elusive chimera for them rather than a fulfilling experience. Untreated mental illness and addiction to substances have shortened the lives of artists such as Vincent Van Gogh, Frida Kahlo, Henri de Toulouse-Lautrec, and Jackson Pollock, all of whom committed suicide. In contrast Edvard Munch and John Callahan, who chose to address their emotional problems and substance abuse, continued to live and remain creative. Choosing to access previously avoided moments of pain can activate the nonlinear power of self-transformation. Language: en
Determinants of Discount Rates in Consumer Credit Decisions

Financial markets offer consumers the ability to gain immediate access to funds in return for future payment obligations. However, research in marketing has not thoroughly examined the determinants of discount rates utilized by consumers to evaluate such offers. This paper examines the role of four determinants: the amount of credit, the timing of the payments, dis-aggregation of the credit obligations, and numeric presentation of the credit amount. Findings from an experiment suggest that consumers’ utilized discount rates significantly vary from those of financial markets, and systematic effects of the above factors on discount rates are also found.
Uhv-Tem Studies of Laser-Induced Damage in Silicon

The effects of pulsed laser irradiation on silicon (111) single crystal thin samples were studied in a ultra-high vacuum transmission electron microscope. Samples were found to cleave along (110) planes under the laser beam. The formation of dislocation networks was also observed. The cleaving did not seem to originate from previously observed defect areas, but from random places, and is believed to be caused by thermal shock from laser beam heating. Bulk defects in the specimens, such as stacking fault tetrahedra and dislocations, were not observed to be affected by the laser treatment.
Morad askari, MD, and steven L. Moran, MD.

I want to thank Dr. Morad Askari and Dr. Steven L. Moran for sharing the responsibility as guest editors of this issue of Seminars in Plastic Surgery on complex upper extremity reconstruction and the talented groups of authors they have invited to this issue. Morad Askari, MD, is an Assistant Professor of Orthopedics and Plastic Surgery at University of Miami, Miller School of Medicine. Dr. Askari obtained his medical degree from University of Pittsburgh School of Medicine. He completed his residency training in the combined General Surgery/Plastic Surgery Program at the University of Southern California-Los Angeles County Medical Center. He then completed a one-year Orthopedic Hand and Microvascular Surgery Fellowship at the Mayo Clinic in Rochester, Minnesota. As a faculty member at the University of Miami, he provides care at the Jackson Memorial Hospital/Ryder Trauma Center, the largest level 1 trauma center in Florida in addition to his other duties in the Departments of Orthopedics and Surgery. Dr. Morad Askari's clinical interests include complex bony and soft tissue trauma of the upper extremity, peripheral nerve and brachial plexus injury, reconstructive microsurgery, management of arthritic hand and wrist, as well as directing the vascularized composite tissue allograft project at the Miami Transplant Institute. Steven L. Moran, MD, is a Professor of Orthopedics and Plastic Surgery and serves as the Division Chief of Plastic & Reconstructive Surgery at the Mayo Clinic in Rochester. Dr. Moran obtained his medical degree from the University of Rochester School of Medicine and Dentistry in Rochester, New York. He completed his residency in General Surgery and Plastic Surgery at the University of Rochester Medical Center. He also completed a one-year research fellowship in plastic surgery at the University of Rochester Medical Center and trained as a clinical fellow in hand and microvascular surgery at the Mayo Graduate School of Medicine. Dr. Moran's clinical interests include pediatric and congenital hand problems, reconstructive microsurgery, and wrist and hand arthritis.
The effect of diagnosing Alzheimer's disease on frequency of physician visits: a case-control study.

OBJECTIVE: Two groups of elderly subjects were studied to see whether patterns of visits to physicians changed after one group received the diagnosis of Alzheimer’s disease. DESIGN: Case—control study. SETTING: Health maintenance organization (HMO). PATIENTS/PARTICIPANTS: Two groups of ambulatory subjects (mean age 77 years) were enrolled from an HMO population for this case—control study: 120 cases had probable Alzheimer’s disease diagnosed at enrollment, and another 120 cognitively intact controls with similar comorbidity were enrolled after being frequency-matched for age and gender. Exclusion criteria were nursing home admission and death during the study period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records were examined for a four-year period: two years prior to and two years following enrollment and diagnosis. Physician visits declined slightly after enrollment for the persons receiving the diagnosis of Alzheimer’s disease [17.5/2 years prior vs 16.5/2 years after (NS)], whereas visits increased over time for the controls [13.7/2 vs 16.3/2 (p<0.05)], hence the rates were similar after enrollment [16.5 vs 16.3 (NS)]. The proportion of subjects with fewer visits during the period after enrollment was higher among the cases than it was among the controls [54% vs 37%; odds ratio =2.0 (95% confidence interval =1.6, 3.1)]. Hospitalizations and emergency department use did not change significantly after enrollment. CONCLUSIONS: Physician visit frequency was high before, then decreased after, demented patients received their diagnosis, approaching the frequency in a control population without dementia. This phenomenon cannot be accounted for by nursing home placement, comorbidity, or mortality. Increased hospitalization and emergency department use did not ensue after diagnosis.
A Method for the Measurement of Ionized Magnesium

The role of ionized magnesium (Mg++) in biological processes only recently has received experimental attention and is not yet clearly defined. Several efforts to develop ion-selective electrodes (ISEs) sensitive to magnesium have been reported, and significant progress has been achieved with the use of ionophore-based selective electrodes involving malondiamide subunits. We evaluated a magnesium ISE based on one of these carriers in the AVL 988-4 Na/Mg/Ca/pH analyzer (AVL Scientific, Roswell, Ga). We studied the performance of this analyzer in terms of precision, linearity, and relative accuracy. Precision of the electrode was excellent, with a linear response over the pathologically significant range. Accuracy of Mg++ measurement is difficult to assess because of the lack of a reference method and primary standards. The ISE will provide the much-needed technology for evaluating the use of Mg++ in patient care management.