cssi/SciSciGPT-SciSciNet huggingface dataset:
Consistency tests for elementary functions

The possibility of using consistency tests to determine the quality of an elementary function subroutine has been considered by several authors. Although none of the authors thought highly of the idea, our investigations have led us to conclude that consistency tests do have a definite provable value in some situations. The error in a subroutine has two possible sources: (a) range-reduction and (b) the reduced-range approximation. For instance, in approximating the sine of a large angle one reduces the problem to that of approximating the sine or cosine of an angle in a reduced-range---perhaps [0, π/4]. Since the range-reduction process will then involve subtracting a large integer-multiple of an inaccurately represented π/2, it is clear that the reduced-range argument will be in error by a quantity which varies linearly with the original argument. Since these range-reduction errors are unavoidable and well understood, we have concentrated our efforts on consistency tests which will help to evaluate the quality of a subroutine in the reduced-range approximation. We give three examples. In each case the variable x is supposed to be within the reduced range; the tests are still valid without this condition, but there is a diminished likelihood of our bounds being realistic when x is outside the reduced range.
The Effect of Propranolol on Circulatory Adaptations to Volume and Pressure Loads

Beta-adrenergic blockade with propranolol caused mild impairment in cardiovascular adaptation to volume (blood infusion) and pressure (angiotensin infusion) challenges in the dog. The impairment was manifested by smaller increases in stroke volume and cardiac output. The altered response to angiotensin infusion was completely attributable to β-adrenergic blockade. The possible role of a non-specific effect of propranolol on cardiovascular adjustment to volume stress was also discussed.
Bias correcting confidence intervals for a nearly common property

Abstract Cline, D.B.H. and Spiegelman, C.H., 1991. Bias correcting confidence intervals for a nearly common property. Chemometrics and Intelligent Laboratory System, 11: 131–136. Confidence intervals are an important tool. Realistic confidence intervals account for both random errors and systematic errors (bias). We improve the usual method for combining random and systematic errors. The new methods are simple and often result in increased accuracy for confidence interval levels.
Self-Orthogonal Greedy Codes

In this paper, we examine greedily generated self-orthogonal codes. We show that they are linear, and discuss several properties which they possess. We also look at specific examples of these codes.
Hereditary colorectal cancer syndromes: molecular genetics, genetic counseling, diagnosis and management

Hereditary forms of colorectal cancer, as is the case with virtually all forms of hereditary cancer, show extensive phenotypic and genotypic heterogeneity, a phenomenon discussed throughout this special issue of Familial Cancer. Clearly, the family physician, oncology specialist, genetic counselor, and cancer geneticist must know fully the complexity of hereditary cancer syndromes, their differential diagnosis, in order to establish a diagnosis, direct highly-targeted surveillance and management, and then be able to communicate effectively with the molecular geneticist so that an at-risk patient’s DNA can be tested in accord with the syndrome of concern. Thus, a family with features of the Lynch syndrome will merit microsatellite instability testing, consideration for immunohistochemistry evaluation, and mismatch repair gene testing, while, in contrast, a patient with FAP will require APC testing. However, other germline mutations, yet to be identified, may be important should testing for these mutations prove to be absent and, therein, unrewarding to the patient. Nevertheless, our position is that if the patient’s family history is consistent with one of these syndromes, but a mutation is not found in the family, we still recommend the same surveillance and management strategies for patients from families with an established cancer-causing germline mutation. Our purpose in this paper is to provide a concise coverage of the major hereditary colorectal cancer syndromes, to discuss genetic counseling, molecular genetic evaluation, highly targeted surveillance and management, so that cancer control can be maximized for these high hereditary cancer risk patients.
High-frequency noise in probes immersed in gas discharges

Probes immersed in a gas discharge give noise with an equivalent saturated diode current I/sub eq/=(I/sub eqO/ + A omega /sup alpha / and an a-c probe conductance G/sub p/ = (G/sub po/+ B omega /sup alpha /), where alpha approx equal 1.3 f or an unshielded probe in an unshielded tube and alpha approx equal 2 for a shielded probe in a shielded tube. Since the high- frequency noise can be reduced by shielding, part but not all of the noise seems to come from the capacitive coupling between the probe and the plasma sheath at the glass wall. The values of A and B are only slightly dependent in the tube current. They are practically independent of probe current as long as pah of the current is carried by electrons but both decrease for strongly negative probe bias. This makes it likely that the effect is mainly caused by electrons. The effect cannot be explained by electrons turning in front of the probe and inducing current pulses in the probe. (auth)
The Harm in Looking

Asaresultof therecentgrowthinthefieldofdiagnostic imaging, the US population has been subjected to a 7-fold increase in exposure tomedical radiation since the 1980s.1 Concerns over radiation-induced malignancy continue to mount in the popular2,3 and scientific4-7 press. In this issue of JAMA Pediatrics, Miglioretti et al8 provide valuable data on the use of computed tomography (CT) in pediatrics and the associated radiationexposure in childrenduring the period from 1996 to 2010; the data were derived from a large research network of health maintenance organizations in the United States. The authors used a random sample of CT scans to calculate radiation dosages and to estimate attributable risks of malignancy. In a similar investigationof adults, they found that, in 2010, an average of just over 1 diagnostic imaging test involving radiation was performed perenrollee, for anaverage radiationexposureof 2.34mSv (the equivalentofover200posterior-anterior chest radiographs).6,9 Using the same database, Miglioretti et al8 present several noteworthy findings: (1) the overall use of CT in pediatrics increased 2to 3-fold during this timeperiod, (2) substantial variability existed in the radiation doses used, and (3) projections of the risks of malignancy with the use of certain scans are higher than previously reported (eg, 1 in 300 girls younger than 5 years of age who undergo an abdominal/ pelvis CT scan will develop a subsequent solid tumor).
Erythrocyte Potassium Levels in Pernicious Anemia and Non-Tropical Sprue

SummaryErythrocyte potassium content is unaltered in the relapsed stage of pernicious anemia and non-tropical sprue. No change is noted during the period of reticulocytosis and red blood cell regeneration.
Darwin's Dilemma: Science in the Public Forum

This article explores the basis of the public debate between Darwinian evolution and creationism. Using dramatic analysis, we show that the source for the debate is due to what we call "Darwin's Dilemma," which is found in Darwin's Origin of Species. In the Origin, Darwin extends the mechanistic metaphor featured in Enlightenment science by devising the concept of "natural selection." In the process, however, he also ascribes a motive to nature, which moves his theory outside the boundaries of Enlightenment science. We show that he is aware of this dilemma in his theory, and that he tries to pass it off as a metaphorical maneuver for the sake of brevity. Darwin's inability to resolve this dilemma, however, opens the door for purveyors of creationism and intelligent design. Indeed, much of the debate today over Darwinian evolution still pivots on our inability to come to terms with Darwin's dilemma.
A simple design for an electronic speckle pattern interferometer

An electronic speckle pattern interferometer suitable for use in an undergraduate laboratory is described. This interferometer can be built for a small fraction of the cost of a commercial version and is simple and inexpensive to build and understand. The interferometer is useful for visualizing the normal modes of vibrating objects as well as changes in index of refraction.
Improvement in the Roche‐Wainer‐Thissen stature prediction model: A comparative study

The Roche-Wainer-Thissen (RWT) prediction model, developed in 1975, predicts the adult stature of a child based on age, current stature, current weight, current skeletal age, and the average stature of the parents. Generally, the method has worked well; however, there are certain steps in the procedure that can be improved. Seven variations of the current version of the RWT prediction model are investigated and compared in terms of the accuracy and reliability of prediction, culminating in a recommendation for the prediction of adult stature in Caucasian Americans. The recommended method, called multivariate cubic spline smoothing [MCS2 (1)], uses cubic splines in the smoothing part of the RWT prediction model, resulting in a simpler (i.e., fewer steps) method with smaller maximum deviations between predicted and actual adult statures than the current multivariate semi-metric smoothing (MS2 ) method. © 1993 Wiley-Liss, Inc.
Surface characterization of chromated copper arsenate (CCA)-treated red maple

Red maple wood blocks were treated with chromated copper arsenate (CCA) preservative. The surface quality of both treated and untreated wood was characterized by various analytical techniques. Environmental scanning electron microscopy (ESEM) showed deposits of metal oxides on the cell wall of CCA-treated wood. X-ray photoelectron spectroscopy (XPS) indicated a higher oxygen/carbon ratio on the surface for CCA-treated wood than for untreated controls or water-treated samples. The surface of CCA-treated wood was rougher than that of untreated and water-treated wood. Higher contact angles for CCA-treated wood with water, glycerol, and phenol-formaldehyde adhesive compared with untreated wood indicated poor wettability and a hydrophobic surface, which may partially explain why composites made of CCA-treated wood exhibit low performance, particularly in exterior applications.
Error bounds and strong upper semicontinuity for monotone affine variational inequalities

Global error bounds for possibly degenerate or nondegenerate monotone affine variational inequality problems are given. The error bounds are on an arbitrary point and are in terms of the distance between the given point and a solution to a convex quadratic program. For the monotone linear complementarity problem the convex program is that of minimizing a quadratic function on the nonnegative orthant. These bounds may form the basis of an iterative quadratic programming procedure for solving affine variational inequality problems. A strong upper semicontinuity result is also obtained which may be useful for finitely terminating any convergent algorithm by periodically solving a linear program.
The ambiguity of negation in natural language queries to information retrieval systems

A prototype system to handle negation in natural language queries to information retrieval systems is presented. Whenever a query that has negation is entered, the system will determine whether or not it is necessary for the user to clarify exactly what constituents in the query are being negated. If clarification is needed, the user is presented with a list of choices and asked to select the appropriate one. The algorithm used is based on the results of a survey administered to 64 subjects. The subjects were given a number of queries using negation. For each query, several possible choices for the negated constituent(s) were given. Whenever a lexical unit composed of nouns connected by the conjunction and was negated, there was general agreement on the response. But whenever there were multiple lexical units involved, such as complex lexical units connected by and or prepositional phrases, the subjects were divided on the choices. The results of this survey indicate that it is not possible for a system to automatically disambiguate all uses of negation. However, it is possible for the user interface to handle disambiguation through a clarification dialog during which a user is asked to select from a list of possible interpretations.
The effect of diffusion of a sparingly soluble salt on the emf of a cell without transference

Abstract In concentration cells without transference, one of the electrodes usually involves a sparingly soluble salt. When the solubility of this salt in the solution between the electrodes is no longer negligible compared to the concentration of the other electrolyte present, access of the sparingly soluble salt to the other electrode must be prevented. The concentration gradients existing in such a cell cause deviations from the emf measured under equilibrium conditions. An approximate treatment is suggested for the estimation of errors incurred due to diffusion of the sparingly soluble salt. The need for this correction is demonstrated for emf measurements on cells involving non-aqueous ionizing solvents, in which the solubility of metal halides is usually higher than in their aqueous analogues.
Water Resources Development in AN Environmentally-Conscious ERA

The Sierra Club, which has long fought selected water resource projects that it believes would be environmentally damaging, has come to the conclusion in recent years that much more basic reforms are required in water resources development activities if the demands for environmental quality now evidenced by the American people are to be satisfied. These reforms should not be limited to those that would have a direct effect on the environmental aspects of proposed projects, but also many others long advocated by the economics profession that would have favorable indirect effects. Among the urgent reforms with indirect effects are those involving revision of the procedures used in evaluating proposed projects. These procedures should be revised so that future evaluations will much more accurately reflect the economic and environmental merits of proposed projects. Basic reforms of tax policies are also needed that will eliminate most of the private profit available to those who can persuade the government to increase the value of their land through the construction of water projects. Finally, some additional actions can be taken that will have a direct impact on lessening the adverse environmental impact of water projects beyond the provisions of the National Environmental Policy Act of 1969.
A Molecular Dynamics Study of Epoxy-Based Networks : Cross-Linking Procedure and Prediction of Molecular and Material Properties

Molecular modeling of thermosetting polymers has been presented with special emphasis on building atomistic models. Different approaches to build highly cross-linked polymer networks are discussed. A multistep relaxation procedure for relaxing the molecular topology during cross-linking is proposed. This methodology is then applied to an epoxy-based thermoset (EPON-862/DETDA). Several materials properties such as density, glass transition temperature, thermal expansion coefficient, and volume shrinkage during curing are calculated and found to be in good agreement with experimental results. Along with the material’s properties, the simulations also highlight the distribution of molecular weight buildup and inception of gel point during the network formation.
Actin Reorganization through Dynamic Interactions with Single-Wall Carbon Nanotubes

Single-wall carbon nanotubes (SWCNTs) have been widely used for biological applications in recent years, and thus, it is critical to understand how these inert nanomaterials influence cell behavior. Recently, it has been observed that cellular phenotypes such as proliferation, force generation and growth change upon SWCNT treatment, and SWCNTs directly affect the organization and redistribution of the actin cytoskeleton. However, the interactions between SWCNTs and actin at the molecular level or how this interaction changes actin structure remain largely unknown. Here, we investigated direct interaction of actin with SWCNT using all-atom molecular dynamics simulations and NIR spectroscopy of actin-dispersed SWCNTs. Actin can stably bind to the SWCNT surfaces via hydrophobic interactions but still allows nanotubes to slide and rotate on the actin surface. Our results establish several nanoscale conformational changes for the actin-SWCNT complexes, and we suggest these changes likely induce reorganization of actin filaments observed at larger scales.
Therapy with Infertile Heterosexual Couples: It’s Not About Gender—Or is it?

In spite of medical data that show males are equal to their female partners as a source of a heterosexual couple’s infertility, therapists face many unanswered questions about the extent to which gender influences each partner’s infertility experience in American culture. How is “hers” different from “his?” To what extent should the therapist strive to help the couple define the infertility issue as “ours”? This article explores how the therapist can elicit and be sensitive to gender issues while fostering resilience in the infertile couple.
Recognition of DNA by designed ligands at subnanomolar concentrations

SMALL molecules that specifically bind with high affinity to any predetermined DNA sequence in the human genome would be useful tools in molecular biology and potentially in human medicine. Simple rules have been developed to control rationally the sequence specificity of minor-groove-binding polyamides containing N-methylimidazole and N-methylpyrrole amino acids. Two eight-ring pyrrole–imidazole polyamides differing in sequence by a single amino acid bind specifically to respective six-base-pair target sites which differ in sequence by a single base pair. Binding is observed at subnanomolar concentrations of ligand. The replacement of a single nitrogen atom with a C-H regulates affinity and specificity by two orders of magnitude. The broad range of sequences that can be specifically targeted with pyrrole–imidazole polyamides, coupled with an efficient solid-phase synthesis methodology, identify a powerful class of small molecules for sequence-specific recognition of double-helical DNA.
An effective heuristic for the review period in an inventory model with staggered deliveries and normal demands

Abstract Consider a single-item, periodic review, infinite-horizon, undiscounted, inventory model with stochastic demands, proportional holding and shortage costs, and full backlogging. Orders can arrive in every period, and the cost of receiving them is negligible (as in JIT). Every T periods, one audits the stocks and chooses a delivery schedule for each of the next T periods, thus incurring a fixed audit cost and—when one schedules actual deliveries—a fixed order cost. The problem is to find a review period T and an ordering policy minimizing the average cost. An earlier article developed an algorithm for computing an optimal T , and undertook a numerical study to evaluate various approximations. Assuming normal demands, we characterize the asymptotic behavior (for large μ / σ ) of the optimal T and establish the asymptotic optimality of a heuristic, calculable on a spreadsheet. A numerical study indicates that patterns established here for large μ / σ hold for σ / μ above 2.
CORR Insights®: An Analysis of References Used for the Orthopaedic In-Training Examination: What are Their Levels of Evidence and Journal Impact Factors?

This CORR Insights® is a commentary on the article “An Analysis of References Used for the Orthopaedic In-Training Examination: What are Their Levels of Evidence and Journal Impact Factors?” by Haughom and colleagues available at: DOI: 10.1007/s11999-014-3895-0. The author certifies that he, or any member of his immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research ® editors and board members are on file with the publication and can be viewed on request. The opinions expressed are those of the writers, and do not reflect the opinion or policy of CORR ® or the Association of Bone and Joint Surgeons®. This CORR Insights® comment refers to the article available at DOI: 10.1007/s11999-014-3895-0.
Clinical and immunologic aspects of FeLV-induced immunosuppression.

Abstract Cats exposed to the feline leukemia virus (FeLV) may mount an effective immune response and eliminate the virus, develop a non-viremic, latent infection or become persistently infected and shed the virus. Persistently infected cats commonly die of secondary opportunistic infections that result from FeLV-induced immunosuppression. The acquired immunosuppression is the most frequent and most devastating consequence of FeLV infection in the cat. Immunosuppression is targeted primarily to the cell-mediated immune system and has been attributed to the viral p15e envelope protein. The decreased IgG response and proliferative response to T cell mitogens is thought to be due to a defect in the helper cell function. As a result of T helper cell immunosuppression, infected cats may also have defective cytotoxic lymphocyte and activated macrophage functions which are regulated by their lymphokines. Research has shown that the virus causes a general suppression in the production of T cell-derived lymphokines, including gamma interferon and interleukin 2. A decrease in the function of polymorphonuclear leukocytes has also been reported and may contribute to deaths due to opportunistic infections in FeLV-positive cats. There are numerous parallels between the acquired immunodeficiency syndrome (AIDS) in man and the FeLV-induced immunodeficiency syndrome in cats. Frequent deaths due to opportunistic infections, lymphopenia, depressed cell-mediated immune responses to T cell-dependent antigens despite hypergammaglobulinemia and the presence of a long period of time between infection and the onset of clinical signs are just a few of the syndromes that are similar between the 2 retroviral diseases. A new strain of FeLV, FeLV-FAIDS has been associated with a naturally occurring immunosuppressive syndrome that is strikingly similar to AIDS in man. In addition, a T-lymphotropic retrovirus has recently been identified from cats with an immunodeficiency-like syndrome; this feline lentivirus disease is morphologically similar, but antigenically distinct from the human immunodeficiency virus, the cause of AIDS. Treatment for FeLV immunosuppression is primarily supportive. The development of a soluble tumor cell antigen vaccine has been shown to be efficacious in preventing FeLV infections.
An X-RAY method for predicting anisotropic irradiation growth in Uranium

Abstract A single quantitative parameter for description of preferred orientation was developed for correlation with anisotropic irradiation growth in uranium. The parameter is derived from X-ray diffraction measurements of the type heretofore described by inverse pole figures. The new parameter, called the growth index, GI , formed a smooth curve when plotted against dimensional changes in alpha-rolled uranium plate that had been irradiated to 600 MWD/T (0.077 at % burnup) in the Materials Testing Reactor (MTR) at National Reactor Testing Station, Idaho. The growth index is formulated by weighting the volume of grains in each orientation by a strain tensor for anisotropic growth. Interactions between grains are neglected as a first approximation. The assumption of a tensor weighting factor is based on the observed homogeneous deformation of uranium at constant volume and does not depend on the mechanism by which deformation might occur. The growth index gives a single quantitative value for a given preferred orientation; with this information, controlled irradiation experiments can be performed on other variables that affect anisotropic growth such as fabrication methods, heat treatment, fuel geometry, cladding restraint, neutron flux, burnup, and irradiation temperature.
Refinement and Validation of Atomic Models of the Kv1.2 Potassium Channel Through Molecular Dynamics and Gating Charge Calculations

Voltage-gated potassium (Kv) channels are membrane proteins that respond to changes in transmembrane potential through voltage-sensing domains (VSD). These domains are composed of highly charged transmembrane segments that move in response to changes in electric potential and control opening of the ion conduction gate. Complete atomistic models of Kv1.2, in the open and closed states, have been constructed using the structure prediction program Rosetta and available crystallographic structures. By means of molecular dynamics simulations, the two models are refined in the presence of an external voltage bias leading to stable conformations of the channel in an explicit membrane-solvent environment. Salt-bridge interactions stabilizing the VSD are identified within the VSD and between the charged residues of the VSD and lipid head groups. Conformational changes in the VSD result in the transfer of electric charge across the membrane, that can be measured as a gating current. The magnitude of the gating charge in Kv1.2 potassium channel is calculated from more than 1microsecond of all-atom molecular dynamics simulation. Free energy calculations are performed to determine the individual contribution of several (nine) charged residues of the VSD to the gating charge. The total gating charge obtained for the refined models of the channel is ∼10.5e, indicating that the refined model of the closed resting state most likely represents an intermediate conformation that precedes closing of the channel. Through steered molecular dynamics (SMD) simulations we identify a closed conformation of the channel, corresponding to a gating charge of 12.7e, in accord with experimental values obtained for the Shaker potassium channel.
Kramers-Kronig Calculation of the Grazing Angle Reflection Spectrum of Barrier Oxide Layer on Aluminum

The nature of the grazing angle reflection spectrum of the thin oxide layer formed on the surface of aluminum was examined by Kramers-Kronig calculations. It was confirmed that the 960-cm−1 peak seen in the grazing angle reflection spectrum corresponds to the absorption band at 738 cm−1 of a low-temperature transition alumina such as γ-Al2O3. The large frequency shift toward higher frequencies is explained in terms of the product between the real and imaginary parts of the refractive index of the oxide. Simulation using the Kramers-Kronig calculation showed, in addition, a very weak structure at about 700 cm−1 in the grazing angle reflection spectrum, which was attributed to a peak shifted from the 590-cm−1 absorption peak of γ-Al2O3.
Perseveration of associative strength in rabbit nictitating membrane response conditioning following ISI shifts

The present experiment determined whether associative strength based upon 15 CS-US pairings at various interstimulus intervals (ISIs) could survive shifts of the ISI to influence the subsequent acquisition of the nictitating membrane (NM) CR. The choice of 15 preshift pairings was based upon previous work, which had shown that this training level produced substantial associative strength without NM CR acquisition. Consequently, this experiment, by shifting the ISI before the beginning of CR acquisition, served as an extension to traditional ISI-shift studies that have imposed the manipulation after CR acquisition. The findings of the experiment indicated that 15 preshift pairings in Stage 1 at ISIs from 250 to 4,000 msec were as effective as 15 pairings at a 500-msec ISI in determining the number of trials to the first NM CR in Stage 2 in which the training ISI was 500 msec. Moreover, 15 pairings in Stage 1 at ISIs from 250 to 2,000 msec were equivalent to 15 pairings at 500 msec in controlling the number of trials to 10 successive NM CRs in Stage 2. These outcomes demonstrate that, within a large ISI range, the associative strength based upon relatively few pairings is preserved despite various shifts of the ISI. Therefore, these results suggest that the reductions in CR performance, which have been consistently observed in traditional studies following ISI shifts, are not due to the loss of associative strength.
The analysis of intensity data in diatomic molecules. A criticism of the r-centroid approach

Abstract The r-centroid approximation as a method of analyzing intensity data in diatomic molecules is discussed. Using some bands of the B 3 Π g → A 3 Σ g + of nitrogen as an illustration, it is shown that one cannot always expect all bands to fall on a single curve of R( r ) vs r . The significance of r-centroids is also discussed.
Some Aspects of Variance Spectra of Synoptic Scale Tropospheric Wind Components in Midlatitudes and in the Tropics

Abstract The primary concern of this paper is an examination of the utility of spectral techniques in detecting wave modes of the large-scale tropospheric circulation. Sample time- and space-spectra of meridional winds in middle latitudes are presented. A maximum in the spatial spectra of the transient waves at hemispheric wave numbers 5–7 is shown, in agreement with similar, previously published spectra. The temporal spectra, unlike the spatial spectra, fail to show any significant features that can be attributed to the passage of baroclinic disturbances. (In this paper, the frequency range considered is limited to 0.03–0.50 per day.) The continuum of the coherence statistic between lower and upper tropospheric wind components is highly significant, but no significant “peaks” or maxima exist. Because of recent interest in the dynamics of tropical regions, spectral techniques are employed on meridional wind data for five tropical stations with record lengths of from 3 to 7 yr. At 850 mb, the two stations ...
Comparison of Methods for the Mitigation of Line Disturbances Due to PWM AC Drives

Several methods are used to reduce the line current harmonics created by PWM AC drives, and by doing so, also reduce the voltage distortion at the secondary terminals of the supply transformer. However, each method also impacts the power distribution system in a different way, and has an impact on the operation of the drive itself. This paper will review and compare the effects that harmonic mitigating methods have on the line supply and on the drive. The comparisons are supported by computer simulations of drive systems and verified by extensive tests that were conducted in the lab.
Competition studies in horse spleen ferritin probed by a kinetically inert inhibitor, [Cr(TREN)(H(2)O)(OH)](2+), and a highly luminescent Tb(III) reagent.

The ability of ferritin as an Fe(II) detoxifier and Fe(III) storage protein is limited by its ability to recognize and incorporate Fe(II), which is then oxidized and mineralized at internal protein sites. The Cr(III) amine complex [Cr(N(CH2CH2NH2)3(H2O)(OH)]2+ [abbreviated as Cr(TREN)] is a kinetically inert inhibitor of iron incorporation and mineralization in ferritin. Unlike other inhibitors, Cr(TREN) can only exchange its two aqua/hydroxy ligands. Competition studies between Cr(TREN) and Tb(III) binding have been performed in horse spleen ferritin (HoSF) to probe uptake of Fe(II). From these studies, we propose that Cr(TREN) inhibits Fe(II) uptake by obstructing the routes of metal uptake and by disrupting the early recognition events at the protein surface that precede metal ion uptake. Using an improved luminescence approach to quantify Tb(III) binding to the protein, we demonstrate that Tb(III) cannot interfere with Cr(TREN) binding to ferritin, but that Cr(TREN) dramatically inhibits Tb(III) binding. We show that bound Tb(III) serves as a reliable reporter for Cr(TREN) binding, as the latter efficiently quenches the Tb(III) luminescence via inter-ion energy transfer. Two types of Cr(TREN) binding sites were successfully distinguished from these competition experiments. A common Tb(III)/Cr(TREN) site was identified with stoichiometry of ~0.6 equivalents of metal cation per ferritin subunit. We propose that the sites along the three-fold channels and the ferroxidase sites are common binding sites for Tb(III) and Cr(TREN). The remaining Cr(TREN) (2.4 equivalents of metal ions/subunit) does not compete with Tb(III) but rather blocks Tb(III) access into the cavity and decreases the protein's affinity for Tb(III). Electronic supplementary material is available if you access this article at http://dx.doi.org/10.1007/s00775-002-0409-4. On that page (frame on the left side), a link takes you directly to the supplementary material.
Intrahepatic cholangiocarcinoma: findings on spiral CT during arterial portography

Abstract To attempt to determine the characteristic imaging features of intraheptic cholangiocarcinoma on spiral CT during arterial portography (CTAP), spiral CTAP examinations of 17 patients with pathologically confirmed intrahepatic cholangiocarcinoma were reviewed in consensus by three radiologists. The diameter of the tumors ranged from 1 to 12 cm (mean diameter, 6.6 cm). All tumors (100%) were hypoattenuating masses on spiral CTAP. In 11 cases, the tumor was homogeneous in attenuation (65%). Tumor margins were smooth and regular in 11 cases (65%). Vascular invasion was found in 14 cases (82%). Intrahepatic bile duct dilatation was present in seven cases (41%). This review shows that intrahepatic cholangiocarcinoma is associated with a constellation of findings on spiral CTAP. The presence of a low attenuation homogeneous intrahepatic mass with vascular invasion and intrahepatic bile duct dilatation on spiral CTAP images should raise the possibility of intrahepatic cholangiocarcinoma. However, these findings can be associated with other types of primary and secondary malignant hepatic tumors.
Repetitive Activation of Hypothalamic G Protein-Coupled Receptor 54 with Intravenous Pulses of Kisspeptin in the Juvenile Monkey (Macaca mulatta) Elicits a Sustained Train of Gonadotropin-Releasing Hormone Discharges

The purpose of the present study was to further examine the hypothesis that activation of G protein-coupled receptor 54 (GPR54) signaling at the end of the juvenile phase of primate development is responsible for initiation of gonadarche and the onset of puberty. Accordingly, we determined whether repetitive iv administration of the GPR54 receptor agonist kisspeptin-10 (2 μg as a brief 1-min infusion once every hour for 48 h) to the juvenile male rhesus monkey would prematurely elicit sustained, pulsatile release of hypothalamic GnRH, the neuroendocrine trigger for gonadarche. GnRH release was monitored indirectly by measuring LH secretion from the in situ pituitary, the GnRH responsiveness of which had been heightened before the experiment with an intermittent iv infusion of synthetic GnRH. Agonadal animals (n = 4) were employed to eliminate any confounding and secondary effects of changing feedback signals from the testis. The first brief infusion of kisspeptin-10 evoked an LH discharge that mimicked th...
Working towards a risk prediction model for neural tube defects.

BACKGROUND Several risk factors have been consistently associated with neural tube defects (NTDs). However, the predictive ability of these risk factors in combination has not been evaluated.
F104S c-Mpl responds to a transmembrane domain−binding thrombopoietin receptor agonist: Proof of concept that selected receptor mutations in congenital amegakaryocytic thrombocytopenia can be stimulated with alternative thrombopoietic agents

Objective To determine whether specific c-Mpl mutations might respond to thrombopoietin receptor agonists. Materials and Methods We created cell line models of type II c-Mpl mutations identified in congenital amegakaryocytic thrombocytopenia. We selected F104S c-Mpl for further study because it exhibited surface expression of the receptor. We measured proliferation of cell lines expressing wild-type or F104S c-Mpl in response to thrombopoetin receptor agonists targeting the extracellular (m-AMP4) or transmembrane (LGD-4665) domains of the receptor by 1-methyltetrazole-5-thiol assay. We measured thrombopoietin binding to the mutant receptor using an in vitro thrombopoietin uptake assay and identified F104 as a potentially critical residue for the interaction between the receptor and its ligand by aligning thrombopoietin and erythropoietin receptors from multiple species. Results Cells expressing F104S c-Mpl proliferated in response to LGD-4665, but not thrombopoietin or m-AMP4. Compared to thrombopoietin, LGD-4665 stimulates signaling with delayed kinetics in both wild-type and F104S c-Mpl−expressing cells. Although F104S c-Mpl is expressed on the cell surface in our BaF3 cell line model, the mutant receptor does not bind thrombopoietin. Comparison to the erythropoietin receptor suggests that F104 engages in hydrogen-bonding interactions that are critical for binding to thrombopoietin. Conclusions These findings suggest that a small subset of patients with congenital amegakaryocytic thrombocytopenia might respond to treatment with thrombopoietin receptor agonists, but that responsiveness will depend on the type of mutation and agonist used. We postulate that F104 is critical for thrombopoietin binding. The kinetics of signaling in response to a transmembrane domain−binding agonist are delayed in comparison to thrombopoietin.
Quantitative Crystallinity Determinations for β-Lactam Antibiotics by Solution Calorimetry: Correlations with Stability

The solution calorimetry method is based on the observation that amorphous forms are normally significantly higher in energy than are crystalline forms. The utility and validity of the calorimetric method were investigated for cephalothin sodium, cefazolin sodium, cefamandole nafate, and cefamandole sodium. Amorphous, partially crystalline, and crystalline forms were prepared and characterized by X-ray diffraction (powder), by solution calorimetry, and, for cephalothin sodium, by the thermal decomposition rate at 50 degrees. Qualitatively, there was a good correlation between calorimetric crystallinity and the (less precise) crystallinity derived from X-ray data. The energy and structure of the amorphous state depend on the history of the sample; even samples of the same crystalline polymorph, containing no amorphous phase, may differ in energy. Thus, the absolute value of the crystallinity (X-ray or calorimetric) depends on the choice of amorphous and crystalline standards. The heat of solution is a precise (+/- 1%) and unambiguous measure of the relative crystallinity; and provided amorphous and crystalline standards are appropriately chosen, the calorimetric crystallinity correlates well with chemical stability.
Delayed uterine re-inversion: A unique symptom complex

A case of late recurrence of uterine inversion is presented. Symptoms included constipation and urinary retention without uterine bleeding. Symptoms resolved 3 months after the replacement of the uterus. It is hypothesized that the symptoms were related to stretch injury to the pelvic parasympathetic nerves. Timely intervention may prevent long-term sequelae.
Searching for stochastic gravitational-wave background with the co-located LIGO interferometers

This paper presents techniques developed by the LIGO Scientic Collaboration to search for the stochastic gravitational-wave background using the co-located pair of LIGO interferometers at Hanford, WA. We use correlations between interferometers and environment monitoring instruments, as well as time-shifts between two interferometers (described here for the first time) to identify correlated noise from non-gravitational sources. We veto particularly noisy frequency bands and assess the level of residual non-gravitational coupling that exists in the surviving data.
Practice patterns of obstetrician-gynecologists regarding preconception and prenatal screening for cystic fibrosis.

Objective: To assess practices of obstetrician-gynecologists regarding carrier screening for cystic fibrosis (CF). Methods: A questionnaire investigating practice patterns and opinions pertaining to CF screening was mailed to 1165 members of the American College of Obstetricians and Gynecologists (ACOG), of whom 565 participate in the Collaborative Ambulatory Research Network (CARN) and 600 were randomly selected. Results: Of the questionnaires, 64% were returned. Statistical analyses were limited to the 632 respondents whose primary medical specialty was gynecology (Gyn Only) or obstetrics and gynecology (ObGyn). CARN membership was not a significant factor on any nondemographic measure. Almost one-half of physicians do not ask nonpregnant patients their family history of CF or provide them with information about CF screening. The majority of ObGyns (88.7%) ask obstetric patients their family history of CF, and offer CF carrier screening. Almost two-thirds (65.8%) offer screening to all prenatal patients. Among those ObGyns who selectively offer CF screening to pregnant patients, only 27.4% utilized all of the selection criteria in the guidelines. Liability for not offering screening, familiarity with CF, and the ability to interpret a positive screening test were important physician concerns. Conclusion: The results indicate a need for minimizing the complexity of clinical guidelines for population-based genetic screening, prospective assessment of implementation and focused continuing education for providers.
Efficient Synthesis of α-C-Galactosyl Ceramide Immunostimulants: Use of Ethylene-Promoted Olefin Cross-Metathesis

Olefin cross-metathesis has been used to prepare α-C-galactosylceramide derivatives. The metathesis process merged vinyl and propenyl glycosides with vinyl derivatives of phytosphingosine. The use of ethylene enhanced the yield of the methathesis step.
NMR Investigation of the Local Dopant-Hydrogen Configuration in Amorphous Silicon

Hydrogen’s role in the doping efficiency and long term stability of hydrogenated amorphous silicon is not well understood. The introduction of dopants has been observed to cause an increase in the deposition rate and in the formation of dangling bonds. We have performed NMR spin echo double resonance measurements on heavily doped amorphous silicon samples prepared via plasma deposition in order to ascertain the dopanthydrogen structural units. The resulting dopant concentrations were 2.0 and 0.5 at. % boron and/or phosphorus in compensated and singly doped material respectively. Our results indicate no direct dopant-hydrogen bonding in the compensated or n-type samples. However, in the p-type material the data indicate that approximately 40% of the boron atoms are directly bonded to a hydrogen.
Multiple amylase genes in two strains of Bacillus stearothermophilus.

Abstract Plasmid DNA fragments from Bacillus stearothermophilus ATCC29609 (BR135) and chromosomal DNA fragments from B. stearothermophilus ATCC31195 (BR132) were cloned into pBR322 and transformed into Escherichia coli strain HB 101. Clones were selected which demonstrate extracellular expression of thermostable amylase. The DNA inserts from both strains showed similar restriction maps. Examination of the parental strains revealed plasmids of approx. 100 kb and 35 kb for BR135 and no discernible plasmids for BR132. Hybridization experiments showed that the amylase gene is contained within a 3.2-kb Hin dIII fragment on both plasmids, and to be present in multiple copies in the BR135 chromosome. Multiple chromosomal copies of the amylase gene were also observed for BR132. Purification of the α-amylase produced by the cloned plasmid amy gene yielded a homogeneous 58-kDa protein with thermostable amylase activity.
Behavioral analysis of male and female Fmr1 knockout mice on C57BL/6 background

Fragile X syndrome (FXS) is a monogenic disease caused by mutations in the FMR1 gene. The Fmr1 knockout (KO) mice show many aspects of FXS-related phenotypes, and have been used as a major pre-clinical model for FXS. Although FXS occurs in both male and female patients, most studies on the mouse model use male animals. Few studies test whether gender affects the face validity of the mouse model. Here, we examined multiple behavioral phenotypes with male hemizygous and female homozygous Fmr1 KO mice on C57BL/6 background. For each behavioral paradigm, we examined multiple cohorts from different litters. We found that both male and female Fmr1 KO mice displayed significant audiogenic seizures, hyperactivity in the open field test, deficits in passive avoidance and contextual fear memory, and significant enhancement of PPI at low stimulus intensity. Male and female Fmr1 KO mice also showed more transitional movement between the lit and dark chambers in the light-dark tests. The lack of gender effects suggests that the Fmr1 KO mouse is a reasonable tool to test the efficacy of potential FXS therapies.
Using highly dispersive fiber gratings as wavelength-tunable true-time-delay in phased array antenna

We have designed, assembled and tested a phase-array antenna using fiber Bragg gratings in the highly dispersive transmission region as our tunable true-time delay (TTD) generators. The TTD generator is designed by cascading 29 identical fiber gratings and 1×2 fiber splitter pairs. Tapping from each fiber splitter allows us to steer our RF microwave beam from a 30×4-element antenna by tuning the wavelength of a laser. The 10Ghz RF signal is superimposed upon a laser beam by means of a LiNbO 3 modulator. However, with a conventional modulator, the optical frequency spectrum of the modulated beam consists of two sidebands on opposite sides of the optical carrier; all three of which may experience very different time delays due to dispersion. This may have detrimental effects on time-delay sensitive processes such as antenna beamforming. Therefore, we studied the use of single-sideband versus double-sideband modulators in the transmitters of photonic phased array antenna. We focus in particular on the effect of the different spectral profiles of single and double sideband modulators on beamforming when using the fiber Bragg gratings as TTD generators. With very high dispersion in our fiber Bragg gratings close to the band edge, the absolute propagation times are different for each sideband and the optical carrier. Therefore double sideband modulated signals will generate two sets of separate delays in the same microwave signal which causes beam deterioration and increased side-lobes. We demonstrated this theoretically and verified experimentally by comparing the antenna patterns generated by single-side-band and by double sideband modulators.