cssi/SciSciGPT-SciSciNet huggingface dataset:
Reply: How molecular motors work in muscle

Howard replies — Huxley points out that there is a discrepancy between recent mechanical recordings from single myosin molecules in vitro and earlier mechanical measurements from muscle fibres in vivo: the single-molecule recordings indicate a working distance and maximum duty ratio of 4-6 nm and 10-20%, respectively, only about half the values deduced from the fibrestudies. Although it is possible that technical limitations, for example misorientated heads, make the single-molecule recordings suspect, I argued in my ReviewArticle1 that the discrepancy might be only an apparent one. In particular, the smaller working distance does conform to many of the results from muscle, and the lower duty ratio can even provide a more satisfactory explanation for some of the experiments with muscle fibres. Huxley challenges this view by discussing three additional observations from fibres. But I believe that these too are mainly consistent with the smaller working stroke and duty ratio.
Stalked Bacteria: Properties of Deoxriybonucleic Acid Bacteriophage φCbK

The Caulobacter crescentus bacteriophage phiCbK was studied with respect to the physical and chemical properties of both the phage and its deoxyribonucleic acid (DNA). Electron micrographs reveal the phage to be among the largest DNA bacteriophages reported, with head dimensions of 64 by 195 nm and a flexible tail 275 nm in length. The phage is composed of 57% DNA. This DNA is double-stranded as indicated by (i) the sharp increase in extinction coefficient over a narrow range of temperature increase, (ii) an increase in density in CsCl upon thermal denaturation, and (iii) the equivalence of guanine and cytosine as well as adenine and thymine, determined by chemical analysis. phiCbK DNA cosediments with Escherichia coli phage T2 DNA and has therefore been assigned an S(20,w) value of 63.5S. The size of the phage and its DNA and the percentage of DNA indicate that the phiCbK phage head is relatively loosely packed. The properties of the DNA from bacteriophage phiCbK are similar to those of host C. crescentus DNA with respect to buoyant density, thermal transition point, and guanine plus cytosine content.
Localization in the ground-state of the one-dimensional $X$-$Y$ model with a random transverse field

We consider the ground-state of the quantum spin model\(H = - J\Sigma _{\langle i,j\rangle } [\sigma _x (i)\sigma _x (j) + \sigma _y (i)\sigma _y (j)] + \Sigma _i h_i \sigma _z (i)\) in one-dimension, where {hi, ieZ} are independent identically distributed random variables. By means of a Jordan-Wigner transformation the model is mapped into a free Fermi gas in the presence of a random external potential. We then use exponential localization of the one particle states to prove exponential decay for the spin-spin correlation functions.
E-commerce and decision technologies: research opportunities and challenges

In this talk, the author motivates the important role that decision technologies play in electronic commerce. Decision technologies - algorithmic and model-based methods to assist decision-making - are a contribution of scholars in the operations research and management science (OR/MS) communities. In conjunction with information technologies, they power many electronic commerce applications. To provide context and to motivate key research themes addressed in this literature, the author draws on his own work and a recent set of special issues on electronic commerce of the management science journal that he co-edited. In particular, he proposes to highlight work in a set of diverse e-commerce topics such as shopbot design, evaluation of information revelation policies and incremental bidding mechanisms in e-markets, peer-to-peer infrastructure design for digital goods and privacy. In each of these illustrative examples, he sketches methodological approaches (e.g., Markov decision processes, game theory, mathematical programming, statistical analysis) underlying the decision technologies and discuss opportunities for further work. The objective is to engender further interest in research opportunities at the intersection of computer science and OR/MS.
Estimations of the increasing prevalence and plateau prevalence of chronic myeloid leukemia in the era of tyrosine kinase inhibitor therapy.

BACKGROUND: The annual incidence of chronic myeloid leukemia (CML) in the United States is approximately 4800 cases. With the success of tyrosine kinase inhibitor (TKI) therapy, the all-cause annual mortality rate was reduced to 2%. Therefore, the prevalence of CML is increasing over time. Estimating the CML prevalence and plateau prevalence is important in the implementation of health care strategies and future therapeutic trials. The objective of this report was to estimate the increasing prevalence and plateau prevalence of CML in future years. METHODS: The prevalence of CML was estimated based on several parameters: the annual mortality rate on TKI therapy compared with a age-matched, normal population; the incidence of CML; the anticipated population growth in the United States; and aging of the population. RESULTS: On the basis of these calculations, the mortality ratio of patients with CML compared with an age-matched normal population was approximately 1.53. The estimated prevalence of CML is approximately 70,000 in 2010, 112,000 in 2020, 144,000 in 2030, 167,000 in 2040, and 181,000 in 2050, when it will reach a near plateau prevalence. CONCLUSIONS: The current results indicated that the prevalence of CML will continue to increase to reach a near plateau prevalence 35 times the annual incidence. These estimates should be considered in health care policies and in the design of future studies in CML. Cancer 2012;118: 3123–27. © 2012 American Cancer Society.
Elastic interpretation of the glass transition in aluminosilicate liquids

One of the remaining puzzles of the glass transition is the origin of a glass-forming liquid's ``fragility,'' which quantifies the departure of its relaxation time from Arrhenius-activated kinetics. According to the shoving model proposed by Dyre, fragility is controlled by the instantaneous shear modulus of the liquid, since any flow event requires a local volume increase, and the related activation energy is equal to the work done in shoving aside the surrounding atoms. Here, we present an in situ high-temperature Brillouin spectroscopy test of the shoving model near the glass transition of eight aluminosilicate glass-forming systems. We find that the measured viscosity data agree qualitatively with the measured temperature dependence of shear moduli, as predicted by the shoving model. However, the model systematically underpredicts the values of fragility for our aluminosilicate liquids. This suggests that the dynamics of the glass transition are governed by additional factors beyond the evolution of the shear modulus, such as configurational entropy. We have also compared the glass transition temperature $({T}_{\mathrm{g},\mathrm{vis}})$ obtained from viscosity (temperature at 10${}^{12}$ Pa s) with the onset temperatures of the decrease in elastic moduli (${T}_{\mathrm{g},\mathrm{elas}}$) and increase in the thermal expansion coefficient (${T}_{\mathrm{g},\mathrm{CTE}}$) during heating. While we find an approximate one-to-one correlation between ${T}_{\mathrm{g},\mathrm{vis}}$ and ${T}_{\mathrm{g},\mathrm{CTE}}$, it is clear that the elastic moduli probe a different frequency response of the glass structure, since ${T}_{\mathrm{g},\mathrm{elas}}$ is systematically lower than ${T}_{\mathrm{g},\mathrm{vis}}$.
RELAXATION ON RECORD

Abstract Tense and anxious patients can be taught to relax by a series of graded tape-recorded exercises. The recordings have proved useful both for groups in hospital and for individual patients at home. No highly specialised experience is required to use them; and they are generally available through the Royal College of General Practitioners.
Epitaxial Growth of Rare-Earth Gallates on Single-Crystal Oxide Substrates

Epitaxial films of lanthanum gallate, praseodymium gallate, and neodymium gallate were prepared on [100] strontium titanate and [100] lanthanum aluminate single crystal substrates using solution techniques. The solutions employed were mixed-metal methoxyethoxides in 2-methoxyethanol. Films were prepared by spin-coating with a partially hydrolyzed solution, followed by firing at 850 °C for 20 minutes in air. Theta/2-theta scans revealed only [ h 00] reflections and omega scans (rocking curves) indicated good out-of-plane orientation. Pole figures and phi scans revealed good in-plane orientation and a [100] || [100] epitaxial relationship between the film and the substrate.
Short-term amphotericin B treatment of severe childhood histoplasmosis

For this paper which records good results in the therapy of disseminated histoplasmosis in infants and small children we are dispensing with the usual abstract and recording excerpts from correspondence with the authors that tend to put the principal considerations at issue into focus. From letter of W. E. N. to W. E. W.: You will note that the reviewers question … whether all of the patients were sick enough to justify potentially toxic therapy with amphotericin B. Another point is the implication that 7–10 days of therapy may almost always be enough. From letter of W.E.W. to W.E.N.: We recognize that serious histoplasmosis is not always fatal but few cases of disseminated disease in which the patient has recovered without treatment have been reported in babies less than a year of age. Certainly we treat only a few of our patients with histoplasmosis, only the ones we think are apt to have a fatal termination or suffer long and damaging illness. At the present cost of hospitalization it seems poor medical practice to withhold treatment and care for the patient in the hospital while he gets sicker and sicker. Blood or bone marrow cultures may take a few weeks or more to become positive and by that time the patient may require a prolonged course of treatment with a drug which shows most of its toxicity after a number of days of administration.
QUANTITATIVE ASPECTS OF MARRIAGE, FERTILITY AND FAMILY LIMITATION IN NINETEENTH CENTURY AMERICA: ANOTHER APPLICATION OF THE COALE SPECIFICATIONS

This paper deals with three aspects of the decline in the fertility of white women in the United States from 1800 to 1920. The first concerns the portion of the secular decline in the total fertility rate which was due to changes in marriage rates and the portion due to decreases in marital fertility rates. The second concerns the fraction of couples in the nineteenth century who acted effectively to reduce their fertility and the third deals with the importance of abortion as a family-limiting practice among white couples in the nineteenth century.
Compression scheme for digital cinema application

In this paper we present a compression scheme for the Digital Cinema application. Specifically, we developed a rate allocation algorithm for applying JPEG-2000 to coding Digital Cinema movies to achieve near lossless and smooth visual picture quality over the decoded movies at the required coding rate. First, a rate-distortion model is established based on the estimated source characteristics of the pictures, and a rate allocation algorithm is derived to determine a target rate for each picture based on the model so that 1) the overall distortion is minimized and 2) each picture has the same distortion at the required average bit rate. Then JPEG-2000 is employed to encode the high resolution motion picture according to the target rate allocation to achieve efficient compression performance and smooth picture quality over the picture sequence. The test results on Digital Cinema movie clips have shown that our scheme has achieved near lossless coding performance and very smooth picture quality both visually and in PSNR.
Assessment of off-flavor development in restructured chicken nuggets using hexanal and TBARS measurements and sensory evaluation

The hexanal contents of chicken nuggets treated with various anti-oxidants were evaluated in relation to the development of warmed-over flavor (WOF) during frozen storage. Of the antioxidant treatments tested, the sodium tripolyphosphate (STPP)/tertiary butylhydroquinone combination showed the greatest effect by decreasing hexanal production by 95%. Combinations of STPP/oleoresin rosemary, (0.5 g kg−1 and 1 g kg−1) decreased the hexanal contents by 85% and 91%, respectively. A higher correlation coefficient (pooled, within treatments) between hexanal contents and sensory scores for WOF (r = 0.68) relative to that between hexanal contents and thiobarbituric acid reactive substances values (r = 0.14) was obtained. A pooled, correlation coefficient within treatments and storage times (r = 0.56), was found between TBARS and sensory scores. It was concluded that the use of correlation coefficients calculated without pooling groups of data within each significant experimental factor to interrelate the results of different analyses may be inappropriate.
Acid‐Base equilibrium in aerobic fermentations: Influence of unutilizable acids and bases on the acetic acid concentration in culture liquid

An investigation was made on the factors influencing the acetic acid concentration in the culture liquid of the aerobic fermentations where acetie acid was used as a carbon source. The acetic acid concentration in the culture liquid changed in proportion to the amount of unutilizable acid or base supplied. This was explained by the principle of conservation of electroneutrality. Another factor affecting the acetic acid concentration in the culture liquid was bicarbonate ions which were formed by the dissolution and dissociation of carbon dioxide in the gas phase of the fermentor. The increment in bicarbonate ion concentration was equal to the decrement in the acetie acid concentration in the culture liquid.
Combined die-investment stone and die-stone cast for making resin-retained prostheses

A technique has been presented for developing a combined die-investment stone/die stone-full arch working cast for use in making a resin-retained prosthesis. The advantage of the technique is that it affords the opportunity to articulate the working cast with a cast of the opposing arch and make the framework directly on a refractory material, while minimizing the subsequent need to trim the refractory material.
Metabolism of murine and human embryos: Search for a growth indicator in vitro culture medium

Ham's F-10 medium was analyzed biochemically before and after growth of murine and human embryos. Ham's F-10 medium (280 mosm/kg, pH 7.4) alone, by means of reverse-phase high-performance liquid chromatography, demonstrated one major hydrophilic peak, which eluted at 4 to 8 minutes in a 10% to 48% acetonitrile gradient. This peak showed a single peptide of 50 kilodaltons in one-dimensional polyacrylamide gel electrophoresis and size exclusion high-performance liquid chromatography. After the growth of two-cell murine embryos to eight-cell embryos or blastocysts, the major hydrophilic peak was greatly reduced or absent in the culture medium, and in turn a major hydrophobic peak appeared that eluted at 29 minutes. The major hydrophobic peak could not be focused in one-dimensional polyacrylamide gel electrophoresis, but a high content of polar and nonpolar amino acids was revealed in N-terminal sequencing and mass spectrometric analysis. This shift in the peaks was not detected when embryos were cultured in the presence of 0.02% sodium azide. In vitro culture of human zygotes from the pronuclear stage to two to eight cells caused a similar disappearance of the major hydrophilic peak concomitant with the appearance of one to three major hydrophobic peaks in the culture medium. We conclude that the change in profile of culture medium from hydrophilic to hydrophobic peaks on high-performance liquid chromatography is indicative of the metabolic pattern of murine and human embryos. These data also indicate that murine and human embryos do not secrete any major peptide during their development in vitro.
Characterization of the discriminative stimulus properties of centrally administered (-)-DOM and LSD.

Abstract Despite the plausible assumption that the effects of hallucinogens predominantly arise in the central nervous system, most studies of these drugs in intact subjects have been conducted following systemic administration. The objective of the present investigation was to characterize the stimulus effects of (−)2,5-dimethoxy-4-methylamphetamine ((−)-DOM) following intracerebroventricular administration. Chronic indwelling cannulae were implanted into the lateral ventricle of male Fischer 344 rats trained to discriminate systemically administered (−)-DOM or lysergic acid diethylamide (LSD) from saline. Time–course and dose–response relationships for (−)-DOM and LSD administered intracerebroventricularly were established. For both LSD and (−)-DOM, central administration did not change the pretreatment times required for the maximal stimulus effects to occur. However, the onset of the stimulus effect was more rapid following intracerebroventricular administration. Following pretreatment periods that maximize drug-appropriate responding, central administration of (−)-DOM and LSD was approximately 2.4- and 1.5-times more potent, respectively, than systemic administration. The results of this study are consistent with the assumption that the stimulus effects of (−)-DOM and LSD are centrally mediated.
Reinforcing vulnerability? Disaster relief, recovery, and response to the 2001 flood in Rawalpindi, Pakistan

Abstract The paper conducts a retrospective analysis of the relief and recovery efforts in the aftermath of the 2001 flood disaster in the Rawalpindi–Islamabad conurbation in Pakistan. The concept of recovery back to “normal” is questioned because “normal” life in the study area was characterized by extreme poverty, injustice, exposure, and vulnerability to hazards. A strong gender dimension to the experience of relief and recovery was found from the case study. It is suggested that participatory approach to needs assessment and actual relief and recovery, with special attention to gender variables, will go a long way towards linking recovery with long-term vulnerability mitigation.
Mental Models and Computer-Based Scientific Inquiry Learning: Effects of Mechanistic Cues on Adolescent Representation and Reasoning About Causal Systems

This research applies cognitive science to the development and study of computer-based scientific inquiry learning. A scientific inquiry software program designed in the domain of elementary hydrology was adapted for mental model reasoning research, and tested in two middle school science classes. The study explores how qualitative mechanistic cues about system factors influence mental animation of system mechanisms and reasoning about causality. Middle school groups were compared on model development, inquiry, prediction, and learning. Students provided with mechanistic cues during inquiry developed more complex models with significantly more animated explanations of how and why causality exists. When not provided with mechanistic information, students reduced the level of complexity and animation in models during inquiry. Girls started with more complex and animated models than boys and reduced the level of complexity and animation in models during inquiry, whereas boys increased the level of complexity and animation in models. Students provided with mechanistic cues had more accurate theories after inquiry than students not provided with mechanistic cues. There was a trend toward use of better inquiry strategies and more accurate prediction in girls provided with mechanistic cues. Level of animation in model descriptions was a significant predictor of developing accurate theories.
γ-Aminobutyric acid receptor type A receptor potentiation reduces firing of neuronal assemblies in a computational cortical model.

Background The understanding of how general anesthetics act on individual cells and on global brain function has increased significantly during the last decade. What remains poorly understood is how anesthetics act at intermediate scales. Several major theories emphasize the importance of neuronal groups, sets of strongly connected neurons that fire in a time-locked fashion, in all aspects of brain function, particularly as a necessary substrate of consciousness. The authors have undertaken computer modeling to determine how a-aminobutyric acid receptor type A (GABAA) receptor potentiating agents such as propofol may influence the dynamics of neuronal group formation and ongoing activity. Methods A computer model of a cortical network with connections modified by synaptic plasticity was examined. At baseline, the model spontaneously formed neuronal groups. Direct effects of GABAA receptor potentiation and indirect effects on input drive were then examined to study their effects on this process. Results Potentiation of GABAA inhibition and input drive reduction reduced the firing frequency of inhibitory and excitatory neurons in a dose-dependent manner. The diminution in spiking rates led to dramatic reductions in the firing frequency of neuronal groups. Simulated electroencephalographic output from the model at baseline exhibits gamma and theta rhythmicity. The direct and indirect GABAA effects reduce the amplitude of these underlying rhythms and modestly slow the gamma rhythm. Conclusions GABAA facilitation both directly and indirectly inhibits the ability of neurons to form groups spontaneously. A lack of group formation is consistent with some theories of anesthetic-induced loss of memory formation and consciousness.
Gram-negative respiratory bacteria which cause ropy milk constitute a distinct cluster within the genusAcinetobacter

Eight strains of Gram-negative respiratory bacteria that produce ropiness in milk were characterized with respect to morphology, physiology, and DNA base composition. All were found to belong to one of the major groups of the genusAcinetobacter. The results of tests for the utilization of 50 different compounds as sole source of carbon and energy were used for a numerical analysis in which 20 strains ofAcinetobacter characterized by other investigators were included. The eight ropy-milk strains, and one previously described, were found to cluster together. The characteristics differentiating the members of this cluster from other strains ofAcinetobacter were determined.
Description of the mean behaviour of ionospheric plasma temperatures

A status report on the empirical modeling of ionospheric electron and ion temperatures is given with special emphasis on the models used in the International Reference Ionosphere (IRI). Electron temperature models have now reached a state where reliable prediction of the mean altitudinal, latitudinal and diurnal variations is possible. These models are largely based on satellite measurements, but comparisons with incoherent scatter radar measurements have shown excellent agreement. Variations with season and magnetic and solar activity seem to be small and are not yet included consistently in these models. Similar to the electron temperature, the ion temperature shows the largest variations with altitude, latitude and local time. But due to the larger mass, these variations are smoother and more steady in the case of the ions and therefore easier to model. Nevertheless, very few ion temperature models exist. The IRI model takes advantage of the observed concurrence of the ion temperature with the neutral temperature at low altitudes and with the electron temperature at high altitudes.
Characterization of an isolated chloroplast membrane FeS protein and its identification as the photosystem I FeSA/FeSB binding protein

An iron-sulfur protein of approx. 9 kDa has been isolated from spinach chloroplast membranes. Based on iron and sulfide content (∼900 nmol Fe and S2− per mg protein), optical absorbance and low-temperature EPR spectra, it appears that this protein contains 8Fe and 8S2− in two [4Fe4S] clusters. The protein cross-reacts with an antibody raised against a 9 kDa PS I subunit previously identified as the psaC (frxA) gene product. This identity was confirmed by the N-terminal amino acid sequence of the isolated FeS protein. It is concluded that the isolated FeS protein binds PS I centers FeSA and FeSB and that each of these centers contains 4Fe and 4S2−.
Frankenstein, racial science, and the yellow peril

(2001). Frankenstein, racial science, and the yellow peril. Nineteenth-Century Contexts: Vol. 23, No. 1, pp. 1-28.
Studies of the Auger spectrum from the (100) surface of GaAs using positron annihilation induced Auger electron spectroscopy

Abstract Measurements of the first high-resolution positron annihilation induced Auger spectrum from GaAs(100) are presented. The spectrum displays six As and three Ga Auger peaks below 110 eV, including a strong As M 4,5 VV peak at 28 eV and a less intense Ga M 2,3 M 4,5 M 4,5 peak at 53 eV. The Auger peak intensities are used to obtain experimental annihilation probabilities for relevant core-level electrons. Experimental results are compared with first-principles calculations of positron surface states and annihilation characteristics of surface trapped positrons.
Magnetic states in amorphous Fe−Pd−Si alloys*

Abstract Low temperature measurements of electrical resistivity, magnetic susceptibility and magnetoresistivity for the amorphous Fe x (Pd 82 Si 18 ) 100− x alloys where x is changed between 0·1 and 0·9 are reported. The amorphous alloys were prepared by rapid quenching from the liquid state. The polarization of the d -electrons of Pd atoms around a Fe atom is found to persist down to the lowest Fe concentration. No giant moment was observed in the present alloys. The effect of the spin polarization on the Kondo type s-d scattering is absent or very small. Interactions between the d -electrons of the Fe atoms, resulting in the superparamagnetic behavior of the alloys seem to take place below a characteristic temperature T d and only at higher fields. This is found to be consistent with the magnetoresistivity data. The results of both electrical and magnetic measurements are in quantitative agreement.
Prognostic Interplay of Coronary Artery Calcification and Underlying Vascular Dysfunction in Patients With Suspected Coronary Artery Disease

Objectives This study sought to evaluate the interrelation of atherosclerotic burden, as assessed by coronary artery calcium (CAC) score and coronary vascular function, as assessed by quantitative estimates of coronary flow reserve (CFR), with respect to prediction of clinical outcomes. Background The contribution of coronary vascular dysfunction, atherosclerotic burden, and the 2 combined to cardiac events is unknown. Method A total of 901 consecutive patients underwent 82 Rubidium myocardial perfusion imaging (MPI) positron emission tomography (PET) and CAC scan. All patients had normal MPI. The primary endpoint was a composite of major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, late revascularization, and admission for heart failure. Results At baseline, CFR decreased (2.15 ± 0.72, 2.02 ± 0.65, and 1.88 ± 0.64, p Conclusions In symptomatic patients with normal MPI, global CFR but not CAC provides significant incremental risk stratification over clinical risk score for prediction of major adverse cardiac events.
Simple rectovaginal fistulas.

In regard to the causes of simple rectovaginal fistulas (RVF) we examined the methods of diagnosis and the efficacy and outcome of surgical procedures. The study included all of our patients diagnosed with simple RVF between December 1988 and July 1998 (n=19). Medical charts of these patients were reviewed regarding diagnostic investigations, operative procedure, outcome, and follow-up. The most common cause was obstetric trauma (n=15, 79%) followed by infection (n=4, 21%). Eight patients (42%) had undergone anal surgery prior to the development of RVF; two of these had undergone more than one procedure. Endoanal ultrasound was performed in 15 patients and identified the fistula in 11 (73%). A concomitant sphincter injury was visualized in 9 of 15 patients (60%). The most common initial operation performed was an endoanal advancement flap in 12 patients (63%). This operation was performed in combination with a sphincteroplasty in 4 patients, while 3 had sphincteroplasty alone. The mean hospital stay was 3 days (range 1– 5). Postoperative morbidity was noted in 5 patients (26%) of and consisted of recurrent fistula and passage of gas per vagina. Surgery was successful in complete resolution of symptoms in 14 cases (74%). Two of the three recurrences were successfully repaired with a repeat endoanal advancement flap, and one is awaiting repair. The mean follow-up for the entire group was 35.8 months (range 6– 84). Endoanal advancement flap should be the initial treatment of choice for simple, low rectovaginal fistulas. The procedure can also be employed with expectations of success even after a failed primary repair and should be combined with a sphincteroplasty if a coexistent anteriorly based anal sphincter defect is noted either by clinical examination or endoanal ultrasonography.
COMPLICATION OF BONE-MARROW TRANSPLANTATION GRAFT-VERSUS-HOST DISEASE RESULTING FROM CHRONIC-MYELOGENOUS-LEUKÆMIA LEUCOCYTE TRANSFUSIONS

Abstract Allogeneic bone-marrow transplantation was attempted in a 12-year-old boy with acute lymphocytic leukaemia. Chronicmyelogenous-leukaemia leucocytes transfused during a period of granulocytopenia became engrafted and resulted in graft-versus-host disease. Allogeneic blood-products should not be transfused into patients with severe drug or irradiation induced immunosuppression without prior in-vitro X-irradiation.
Evidence-based classification of recommendations on use of genomic tests in clinical practice: Dealing with insufficient evidence

Numerous genomic tests continue to emerge as potential tools in the diagnosis, treatment, prognosis, and prevention for a wide variety of common human diseases. To date, most of these tests have "insufficient evidence" of clinical validity and utility for their use in clinical practice. Explicit and quantitative tools can be used in the evaluation of direct and indirect evidence on the utility of genomic tests. As suggested in an article in this month's issue by Veenstra et al., a recommendation matrix can be developed based on the amount of certainty of the evidence and the assessment of the risk-benefit profile. To supplement the current binary (up or down) evidence-based recommendation for use, it is worthwhile to explore all available data to develop a three-tier evidence-based recommendation classification of genomic tests ("use in practice," "promote informed decision-making," and "discourage use"). Promoting informed decision making may be a valuable recommendation for tests for which there is sufficient information on analytic and clinical validity and for which the risk/benefit analysis on clinical utility is promising but not definitive. This approach could provide interim guidance for clinical practice, while rigorous outcomes research is conducted to assess the impact of such tests on patients, families, and population health outcomes.
Solution method for a hovering helicopter rotor using the Euler equations

A method for the calculation of the flow field of a helicopter rotor blade in hover is presented. The approach uses a finite volume solution of the three dimensional Euler equations for the blade near field. In the Euler solver the velocity field is decomposed into two parts. One is the induced velocity of the vortex wake extending below the blade, found from a free wake calculation procedure. The other part is the unknown additional velocity field of the rotor blade. This approach eliminates numerical diffusion of the rolled up wake vorticity due to truncation error and artificial viscosity. Also, the effects of the far wake are included in the limited computational domain. Solutions are presented for an isolated wing and a model helicopter rotor and compared to experiment.
Insidious, Largely Undetected, Fatal Clostridium perfringens Sepsis Resulting in Unbridled Vascular Hemolysis: Concepts Regarding Pathogenesis

© 2012 Elsevier 0196-4399/00 (see frontmatter) 47 Introduction Clostridium perfringens is a grampositive, encapsulated, nonmotile, anaerobic, spore-forming bacillus that is widely distributed in nature and the alimentary tracts of animals and humans (1). When cultured on 5% sheep blood agar, it produces a distinct zone of beta hemolysis surrounded by a secondary, less-intense hemolytic zone. The hemolytic zones on blood agar are attributable to several hemolysins, including the very potent alpha-lecithinase (phospholipase C) toxin. Under ideal growth conditions, C. perfringens has a doubling time of 7 min (2) and, therefore, in a short time span can produce and secrete large amounts of toxins, which can account for most of the clinical manifestations of infections caused by the bacterium. C. perfringens is well known as a virulent pathogen in gas gangrene infections and in food poisoning, as exemplified by enteritis necroticans (pigbel), a necrotizing infection of the jejunum and ileum accompanied by bloody diarrhea (3,4). Other devastating manifestations of C. perfringens invasion include postabortal and postpartum infections, leading to intravascular hemolysis in patients who have undergone abortion (5) or who have sustained trauma. In addition, spontaneous, nontraumatic gas gangrene can occur in Corresponding Author: Steve Xie, M.D., Ph.D., Department of Pathology, Westchester Medical Center, New York Medical College, 100 Woods Rd., Valhalla, NY 10595. Tel.: 914-493-7433. Fax: 914493-1145. E-mail: xies@wcmc.com Case Report
Approach to acute renal failure in biopsy proven myeloma cast nephropathy: is there still a role for plasmapheresis?

A 75-year-old Caucasian man with hypertension and severe, emphysema, presented to the Veterans Administration New York Harbor Health Care System Hospital outpatient clinic, for his bi-yearly physical in March 2003. The patient had a macrocytic anemia and a serum creatinine (Scr) level of 3.3mg per 100 ml (baseline Scr, 0.9 mg per 100 ml 1 month earlier). An outpatient nephrology consultation was initiated after a comprehensive negative gastrointestinal workup. Detailed history and physical examination were performed. He denied the following symptoms: headache, visual changes, hesitancy, frequency, oliguria, dysuria, nausea, vomiting, fever, chills, bone pain, and change in weight, appetite or bowel habits. He also denied the following: hematochezia, melena, fatigue, dyspnea, dizziness, or chest pain. His medications on presentation included lisinopril 20 mg day -1 and combination albuterol and atrovent inhaler. He denied occupational or chemical exposure, and use of herbal or over-the-counter medications. The patient quit smoking and drinking over 20 years ago. He had no history of diabetes mellitus, macroscopic hematuria, or tuberculosis. His family history was non-contributory. Physical examination revealed an alert, healthy-appearing older male with a blood pressure of 134/83 mm Hg (without orthostasis), pulse rate of 78 beats min -1 , weight of 89kg, and body mass index of 29 kg m -2 . There was no lymphadenopathy. Heart examination showed regular rate and rhythm, without murmurs, rubs, or gallops. Lungs were clear to percussion and auscultation. Abdomen had normal bowel sounds, was soft, non-tender, with no masses or hepatomegaly. There was dullness in Traube's space on deep inspiration. Extremities revealed no clubbing, cyanosis, rash, or edema. Neurological examination was essentially normal. Diagnostic studies were performed. Renal ultrasound showed 11.7 and 12.4 cm right and left kidney, respectively. Both kidneys demonstrated mildly increased, diffuse parenchymal echogenicity, consistent with mild medical renal disease, with no scarring or masses. There was no hydronephrosis. Renal veins were patent bilaterally. The bladder was not distended. Spleen was enlarged, measuring 12.6 cm. Results of the laboratory studies are detailed in Table 1. Urinary dipstick showed trace protein but sulfosalicyclic acid testing was not performed. Twenty-four-hour urine protein level was 3.1 g day -1 . Urine protein electrophoresis was unremarkable, but urine and serum immunofixation electrophoresis and serum protein electrophoresis showed a monoclonal band (IgAκ). His quantitative serum immunoglobulin A (IgA) level was 2330 mg per 100ml. Bone marrow biopsy revealed 90% plasma cells (Figure 1). Skeletal survey was negative. A diagnosis of multiple myeloma (MM) Durie-Salmon stage III was made.
The use of a samarium loaded liquid scintillator for the determination of the half-life of Sm147

Abstract An investigation of the use of metal loaded organic liquid scintillators for the study of long lived alpha emitters has been carried out. The method was checked using a samarium loaded scintillator. A specific activity corresponding to a half-life of (1.28 ± 0.04) × 1011 years for the alpha decay of Sm147 was found. This is in agreement with the published half-life measured using a different technique.
Controlling hyperhydration of carnations (Dianthus caryophyllus L.) grown in a mist reactor

Carnations (Dianthus caryophyllus L.) grown in vitro often develop physiological abnormalities such as hyperhydration. The amount of hyperhydration and growth was compared between carnations grown in mist reactors and conventional semisolid micropropagation systems (vented or unvented GA7 culture boxes). Plants grown in the mist reactor with long misting times (10 min h−1) produced more dry mass than those grown with <10 min h−1; however, more misting also produced more hyperhydrated plants (70% hyperhydration). Control of hyperhydration in the mist reactor involved either reducing the overall nutrient mist supply or altering the mist supply throughout the culturing period. Stepped decreases in the mist supply throughout the 3-week period or an overall decrease in the duration of misting reduced hyperhydration to 13% and 5%, respectively. However, for both misting regimes, the biomass of normal (healthy) plants (fresh and dry weights) was limited. Further analysis suggested that, although normal plant biomass increased with longer mist exposure, hyperhydration levels also increased while the water content, based on percent dry weight, approached that of hyperhydrated plants. Sufficient normal plant development (fresh weight, leaf and shoot numbers, height, and rooting) with <50% hyperhydration was obtained by weekly, stepped increases in the nutrient mist supply. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 71: 307–314, 2000/2001.
Lanthanide ions as luminescent chromophores for liquid chromatographic detection

Abstract The chloride and nitrate salts of Tb(III) and Eu(III) can be employed as luminescent chromophores for reversed-phase liquid chromatographic detection. The method is applicable to specific compounds that are capable of either transferring energy to, or quenching the background luminescence of, a lanthanide ion. Addition of the lanthanide ion is achieved through a post-column reaction device. Mobile phases containing methanol and acetonitrile can be employed. Significant quenching of the lanthanide luminescence is observed in mobile phases containing water. This quenching can be reduced by the addition of potassium acetate. Higher temperatures increase the intermolecular energy transfer resulting in an increase in the sensitivity. Oxygen quenches the lanthanide luminescence and measures to remove oxygen from the mobile phase must be taken. The selectivity of the energy transfer can be used to both simplify chromatograms and aid in the identification of compounds.
Postural tachycardia syndrome and reflex syncope: similarities and differences.

As awareness of postural tachycardia syndrome (POTS) has increased in recent years,1-3 our laboratory has received numerous patient referrals for “POTS going to faint.” These comprise patients who, during tilt table testing, have development of excessive tachycardia, sometimes gradually decreasing blood pressure and symptoms of orthostatic intolerance, followed by a simple postural faint (current designation “reflex neurocardiogenic syncope”4). Consider 2 representative teenage patients placed on a tilt table for a 20- to 30-minute supine equilibration period and then tilted upright to 70 degrees. Both have development of excessive increases in heart rate within 5 minutes of the onset of upright tilt (Figure 1). Both become lightheaded and nauseated and have development of progressive neurocognitive impairment. Respirations deepen, and end tidal carbon dioxide is significantly decreased. They are both pale and somewhat diaphoretic. Blood pressure may slowly decrease. Just before pronouncing the diagnosis of POTS, 1 patient abruptly loses consciousness in association with a rapid decrease in blood pressure and heart rate characteristic of the “vasovagal faint” variant of reflex syncope because of the decrease in blood pressure (the vaso or vascular part) followed immediately by a sudden drop in heart rate (the vagal part).5 This causes an equally abrupt change in the diagnosis from POTS to simple faint. The other patient continues to have an excessively increased heart rate and symptoms of orthostatic intolerance but has no decrease in blood pressure or heart rate, or loss of consciousness. Blood pressure and heart rate data for the representative tilt subjects are shown in Figure 1. These scenarios have fostered concerns about the clinical and physiological similarities and differences between simple faint and POTS. The answer appears to be a qualified no to clinical similarity and a qualified yes to physiological similarity. One could easily reverse this question and ask whether there are clinical and physiological differences between simple faint and POTS. The answer appears to be a qualified yes to clinical difference and a qualified no to physiological difference. The most notable differences between POTS and simple fainting are found in their clinical presentations, and therefore history taking is paramount in diagnoses. POTS is a chronic day-to-day form of orthostatic intolerance, and simple faint is most often episodic and associated with long periods of “wellness.” Figure 1 The figure shows heart rate in the top panel and mean arterial pressure in the bottom panel during upright tilt to 70 degrees. A representative patient with POTS is shown in red and a representative patient with syncope is shown in green. Excessive tachycardia ...
Impact of Acute Pulmonary Embolization on Arterial Stiffening and Right Ventricular Function in Dogs

Pulmonary hypertension (PH) can impact right ventricular (RV) function and alter pulmonary artery (PA) stiffness. The response of the RV to an acute increase in pulmonary pressure is unclear. In addition, the relation between total pulmonary arterial compliance and local PA stiffness has not been investigated. We used a combination of right heart catheterization (RHC) and magnetic resonance imaging (MRI) to assess PA stiffening and RV function in dogs before and after acute embolization. We hypothesized that in moderate, acute PH the RV is able to compensate for increased afterload, maintaining adequate coupling. Also, we hypothesized that in the absence of PA remodeling the relative area change in the proximal PA (RAC, a noninvasive index of local area strain) correlates with the total arterial compliance (stroke volume-to-pulse pressure ratio). Our results indicate that, after embolization, RV function is able to accommodate the demand for increased stroke work without uncoupling, albeit at the expense of a reduction of efficiency. In this acute model, RAC showed excellent correlation with total arterial compliance. We used this correlation to assess PA pulse pressure (PP) from noninvasive MRI measurements of stroke volume and RAC. We demonstrated that in acute pulmonary embolism MRI estimates of PP are remarkably close to measurements from RHC. These results, if confirmed in chronic PH and clinically, suggest that monitoring of PH progression by noninvasive methods may be possible.
Hardware for Microprocessor Controlled HPLC: Interfacing of an Interval Timer and Interrupt Controller to the “S100 Bus System”

Abstract A hardware interface for the 8253 Interval Timer and the 8259 Interrupt Controller to the standard “S100 Interface Bus System” is described herein. The interface allows the three timers of the 8253 Interval Timer to be synchronized by either an external trigger or an internal trigger issued by the microprocessor. This permits synchronized control of external devices either by the microprocessor, manually, or otherwise externally. Furthermore, two of the three timers are driven by two independent programmable clocks. This enhances their range, in contrast to a fixed clock, while maintaining the lowest possible error. The addition of the 8259 Interrupt Controller further supplements the flexibility of this interface. It permits the synchronization of software along with the external devices and permits the timers to be used in a “stopwatch” fashion by allowing them and the external trigger to initiate an “interrupt”.
PR or GR

Fifteen Ss each learned 12 paired associates whose response terms represented four form-classes (CMC, VCC, CCV, CCC). The form-classes were equated for PR. However, differences in ease of learning for the various form-classes were statistically significant, both for trials to criterion and for mean number of correct responses in 25 trials. In terms of decreasing ease of learning the form-classes were ordered CCV, CCC, CVC, VCC, contrary to a prediction based on letter-sequence preferences determined by frequency of experience in language (GR).
Boundary conditions for the numerical solution of elliptic equations in exterior regions

Elliptic equations in exterior regions frequently require a boundary condition at infinity to ensure the well-posedness of the problem. Examples of practical applications include the Helmholtz equation and Laplace's equation. Computational procedures based on a direct discretization of the elliptic problem require the replacement of the condition on a finite artificial surface. Direct imposition of the condition at infinity along the finite boundary results in large errors. A sequence of boundary conditions is developed which provides increasingly accurate approximations to the problem in the infinite domain. Estimates of the error due to the finite boundary are obtained for several cases. Computations are presented which demonstrate the increased accuracy that can be obtained by the use of the higher order boundary conditions. The examples are based on a finite element formulation but finite difference methods can also be used.
Mössbauer and DFT Study of the Ferromagnetically Coupled Diiron(IV) Precursor to a Complex with an FeIV2O2 Diamond Core

Recently, we reported the reaction of the (μ-oxo)diiron(III) complex 1 ([FeIII2(μ-O)(μ-O2H3)(L)2]3+, L = tris(3,5-dimethyl-4-methoxypyridyl-2-methyl)amine) with 1 equiv of H2O2 to yield a diiron(IV) intermediate, 2 (Xue, G.; Fiedler, A. T.; Martinho, M.; Munck, E.; Que, L., Jr. Proc. Natl. Acad. Sci. U.S.A. 2008, 105, 20615−20). Upon treatment with HClO4, complex 2 converted to a species with an FeIV2(μ-O)2 diamond core that serves as the only synthetic model to date for the diiron(IV) core proposed for intermediate Q of soluble methane monooxygenase. Here we report detailed Mossbauer and density functional theory (DFT) studies of 2. The Mossbauer studies reveal that 2 has distinct FeIV sites, a and b. Studies in applied magnetic fields show that the spins of sites a and b (Sa = Sb = 1) are ferromagnetically coupled to yield a ground multiplet with S = 2. Analysis of the applied field spectra of the exchange-coupled system yields for site b a set of parameters that matches those obtained for the mononucle...