cssi/SciSciGPT-SciSciNet huggingface dataset:
Time- and dose-response effects of the mycotoxin, fumonisin B1 on sphingoid base elevations in precision-cut rat liver and kidney slices☆

Fumonisins are mycotoxins produced on corn (Zea mays) by the common fungus Fusarium moniliforme. The fumonisins are potent inhibitors of sphingolipid biosynthesis and cause dramatic elevations in the free sphingoid base, sphinganine, both in cells in culture and in urine, blood and tissues of animals dosed with the toxins. In this study the effects of fumonisin B1 (FB1) on sphingoid bases in precision-cut rat liver and kidney slices were evaluated. In liver slices exposed for 20 hr to FB1, as little as 0.1 μM caused a 40-fold elevation in free sphinganine. Kidney slices were less responsive, and a 1 μM dose of FB1 was required to cause a 10-fold increase in sphinganine. The amount of sphinganine in liver slices exposed to FB1 increased in a time-dependent manner over a 72-hr period, but kidney slices exposed to the same doses of FB1 showed a peak elevation of sphinganine after 24 hr, with a decline in the levels over the next 48 hr. Liver slices may more closely approximate the in vivo response of animals to FB, than do primary hepatocytes (in which sphinganine may be elevated > 100-fold), because the elevations in sphinganine were similar to those reported in livers of animals fed fumonisins. On the other hand, the response of kidney slices to FB1 was substantially less than that reported in kidney tissue of FB1-fed rats, suggesting that kidney may accumulate toxic levels of sphingoid bases that are released from other tissues into the blood. The use of tissue slices also appears to be a useful bioassay tool for monitoring corn or other products for toxins, such as fumonisins, that elevate sphinganine levels. Crude extracts of corn screenings naturally contaminated with fumonisins produced significantly elevated sphinganine levels in liver slices, even after 50-fold dilution of the extract.
Ultrafast nonlinear optical spectroscopy of a dual-band negative index metamaterial all-optical switching device

We study the nonlinear optical response of a fishnet structure-metamaterial all-optical switching device that exhibits two near-infrared negative-index resonances. We study and compare the nonlinear optical response at both resonances and identify transient spectral features associated with the negative index resonance. We see a significantly stronger response at the longer wavelength resonance, but identical temporal dynamics at both resonances, providing insight into separately engineering the switching time and switching ratio of such a fishnet structure metamaterial all-optical switch. We also numerically reproduce the nonlinear behavior of our device using the Drude conductivity model and a finite integration technique over wide spectral and pump fluence ranges. Thereby, we show that beyond the linear properties of the device, the magnitude of the pump-probe response is completely described by only two material parameters. These results provide insight into engineering various aspects of the nonlinear response of fishnet structure metamaterials.
Effects of the antiestrogen tamoxiten on low-density lipoprotein concentrations and oxidation in postmenopausal women

Our study demonstrates that tamoxifen, when administered to postmenopausal women at a conventional dosage, reduces LDL levels and protects LDL from oxidation. The protective effect of tamoxifen against the development of breast cancer in women considered at risk is being investigated in a placebo-controlled trial sponsored by the National Institutes of Health. Whether tamoxifen also protects against the development of cardiovascular disease in this trial is also of considerable interest.
Instrumentation for solving abutment parallelism problems in fixed prosthodontics

Abstract Casts from a number of preparations by dentists with a variety of fixed prosthodontic experience levels were surveyed, and the preparations were commonly found to contain undercuts, overtapered surfaces, and lack of a parallel path of insertion. A new instrumentation for preparing abutment teeth was examined, which eliminated the common inaccuracies caused by traditional techniques of using freely held handpieces and visually assessing the finished preparations. Three clinical preparation procedures were discussed. Each patient posed particularly demanding problems that required precise tooth preparation. Each completed prosthesis was readily inserted in the mouth due to the unobstructed uniform path of insertion. Keyways were not required in any of the prostheses.
Developing Cultural Competency in Early Childhood Preservice Educators through a Cultural Self-Analysis Project.

Today more than ever, preparation for diversity is essential for all teachers. Hence, teacher preparation programs are charged with preparing culturally competent teachers who have the knowledge, skills, and disposition to work with children and families from cultures different from their own. This article investigates an innovative approach, the Cultural Self-Analysis (CSA) Project, to accomplish this task with 26 prospective early childhood teachers. CSA Project steps are presented. Data collected on multiple levels were analyzed using constant comparative methodologies. Findings from this initial investigation suggest the CSA Project holds promise as an approach to prepare culturally responsive teachers in three major ways. Participants reported increased confidence and comfort, preparedness to facilitate home connections with culturally diverse persons, and enlightenment of teacher roles/responsibilities beyond academic instruction. We respectfully thank Dr. Laura C. Dominguez and David Grant who kind...
“Where's the Line?”—Negotiating Simulated Experiences to Define Teacher Identity

Teacher professional identity is a concept defined and researched in a multitude of ways (Beijaard, Meijer, & Verloop, 2004). This manuscript approaches teacher identity formation from the foundations of situated cognition, social learning, and identity in community practice. Focusing on a unique teacher development intervention designed to simulate parent-teacher interactions, we examine emerging data on teacher professional boundaries and identity formation. Findings suggest that complex simulations and technology-enhanced video reflections provide novice teachers with opportunities to bridge traditional gaps between educational theory and classroom practice.
Theoretical interpretation and derivation of flash-on-flash threshold parameters in visual system diseases.

Visual increment thresholds measured on backgrounds flashed on simultaneously with the test flash exhibit saturation rather than following Weber’s law. These flash-on-flash thresholds have been modeled with saturating nonlinearities similar to those used to describe intensity-response functions of retinal neurons. Recently, the flash-on-flash technique has been used to assess the mechanisms of threshold elevations in visual system diseases. However, the results were interpreted in a qualitative way. This paper extends the clinical application of flash-on-flash threshold measures by providing a theoretically derived algorithm for estimating nonlinear model parameters from flash-on-flash threshold data. The performance of the algorithm is evaluated with Monte Carlo techniques, and the theoretical interpretations of the model parameters are tested experimentally. Published clinical flash-on-flash threshold data are reanalyzed using the algorithm. A previously unappreciated decrease in the half-saturation constant of retinitis pigmentosa patients was revealed by this analysis.
Improved blood glucose estimation through multi-sensor fusion

Continuous glucose monitoring systems are an integral component of diabetes management. Efforts to improve the accuracy and robustness of these systems are at the forefront of diabetes research. Towards this goal, a multi-sensor approach was evaluated in hospitalized patients. In this paper, we report on a multi-sensor fusion algorithm to combine glucose sensor measurements in a retrospective fashion. The results demonstrate the algorithm's ability to improve the accuracy and robustness of the blood glucose estimation with current glucose sensor technology.
Programming in Franglais: Six of one, half a dozen of d’autre

When I was studying French in high school, we students often spoke “Franglais”: French grammar and words where we knew them, English inserted where our command of French failed us. It was pretty awful, and the teacher did not think highly of it. But we could communicate haltingly because we all had about the same levels of knowledge of the respective languages. Today, there is a kind of programmer’s Franglais that is all too pervasive. Those who are old enough will remember the pitched controversy in the late 1960s and early 1970s over whether compilers, operating systems, and other systems programs should be written in assembly code or a high-level language. The prime argument for the languages was that their higher-level computational model allowed far more function to be coded in the same amount of development time.
Microporous membranes based on poly(ether ether ketone) via thermally-induced phase separation

Abstract The fabrication of poly(ether ether ketone) based membranes via thermally-induced phase separation has been investigated. Microporous membranes were generated from solid-liquid phase separation of miscible polymer-polymer mixtures comprised of PEEK and polyetherimide, with subsequent extraction of the PEI diluent; the introduction of a high polymer diluent provides a number of advantages in terms of melt processing and ultimate membrane properties. The nature of the solid-liquid phase separation and corresponding PEI segregation was investigated as a function of crystallization temperature and diluent molecular weight using dynamic mechanical thermal analysis. DMTA studies revealed segregation of PEL to both interlamellar and interfibrillar/interspherulitic regions. PEI extraction with liquid dichloromethane was found to be site specific, with diluent removal solely from the interfibrillar and interspherulitic regions; the retention of interlamellar PEI in the final article was reflected in a significant increase in the thermal resistance characteristics of the material. Scanning electron microscopy revealed a microporous morphology comprised of a spherulitic superstructure with two distinct pore size scales corresponding to PEI extraction from between fibrillar bundles and in interspherulitic regions, respectively. The relative morphological distribution could be shifted with variations in initial blend composition.
IDENTIFICATION THEORY FOR VARYING COEFFICIENT REGRESSION MODELS1

. The identification problem for regression models with time-varying coefficients is investigated using state-space model representations and some results from linear dynamic systems theory. The approach taken focuses on second moment information and yields global as opposed to local asymptotic results. The form of the equivalence classes that generate the identification problem is first derived and then employed to establish the identification of one of the most natural structural specifications currently employed in econometrics.
4,5-Cyclopropanocholestan-3β-ol Substrates for Cholesterol Oxidase and Their 1H NMR Assignments

We have assayed 4,5-cyclopropanocholestan-3-ols and 4,5-cyclopropanocholestan-3-ones and tested them as substrates and inhibitors of cholesterol oxidase. The 4,5-cyclopropanocholestan-3β-ols (α and β) are substrates of cholesterol oxidase that are converted to their respective ketones 1000-fold more slowly than cholesterol. The induced ring-current effects of a cyclopropane ring are clearly illustrated in the 1H NMR spectra of these sterols. These shielding effects are dramatic because of the rigidity of the steroid backbone. Assignments of the 1H resonances of the A, B, and cyclopropyl rings of the sterols have been made using DQF-COSY and NOESY experiments. We have assigned the upfield multiplet at approximately 0.5 ppm to H6α in both isomers. H6α is shielded by the cyclopropyl σ bond. H6β is deshielded by the cyclopropane ring and appears at approximately 2.0 ppm in both isomers.
Holocene prehistory of the northernmost north Pacific

We examine evidence for Holocene contact between Asia and North America across what is now the Bering Strait, emphasizing maritime adaptation. After ∼10,000 B.P. residual influence of the Siberian Paleolithic is clear, and derivative Americans were moving southward along the open Pacific coast and settling in the eastern Aleutian Islands. By 6000 B.P. maritime adaptation is evident in the Kodiak Island region, and expansion westward brought colonization of the entire Aleutian chain of islands before 3000 B.P. In Asia there was marine subsistence on Hokkaido by 6000 B.P, but in the lower Amur River region, the southern and northern regions of the Okhotsk Sea, the coast of Kamchatka, and the Chukchi Peninsula no major maritime interest can be dated until after 2700 or even 2500 B.P In north Alaska, the mainland was cut off from Siberia by 6000 B.P with the rise of postglacial seas, but contact was reestablished ∼5000 B.P at the cultural level of the nonmaritime Siberian Neolithic. Pronounced marine orientation appears intrusively in north Alaska somewhat before 3000 B.P, when the only known source for the technology was the region extending from the Gulf of Alaska through the Aleutian Islands. Thereafter developed the maritime culture of the historic Eskimo people.
Viral prophylaxis in combined pancreas-kidney transplant recipients

The purpose of this study was to analyze different regimens of viral prophylaxis after combined pancreas-kidney transplantation (PKT). Over a 4-year period, we performed 82 PKTs with quadruple immunosuppression with OKT induction. Four regimens of prophylaxis were studied. The brat 30 patients received standard intravenous immunoglobulin (IVIG; 0.5 g/kg) for 6 doses and oral acyclovir for 3 months. The next 34 recipients received intravenous ganciclovir (2-5 mg/kg) twice daily for 2 weeks followed by oral acyclovir for 3 months. In the third group, patients were randomized to 5 doses over 2 months of either standard IVIG (n=9) or CMV hyperimmune globulin (Cytogam; n=9; 100-150 mg/kg) plus 2 weeks of IV ganciclovir followed by 3 months of oral acyclovir
Enhancement of the electrochemical oxidation of formic acid. Effects of anion adsorption and variation of rotation rate

Abstract Results are presented from a study on the electrochemical oxidation of formic acid. Perturbing a HCOOH+HClO4 solution by causing a small amount of any one of several different anions to be present dramatically changes observed nonlinear behavior in an apparently unique manner. Quantitative changes are also observed. In current-control experiments, the presence of fluoroborate ions causes a substantial increase in the value of the applied current density for which low valued stationary potentials remain stable. In potential-control experiments, the current density substantially increases at relevant potential values. Although most properties possessed by the fluoroborate anion exist among the other anions studied, the presence of any one of these other ions in solution yields inferior current–potential characteristics. Results from current-control experiments show that changes in rotation rates have no effect on the observed behavior regardless of anion composition or whether the limiting state is stationary or oscillating.
Production and separation of (186g)Re from proton bombardment of (186)WC.

Abstract A proof of concept study was undertaken where non-carrier added 186g Re was produced from the cyclotron bombardment of 186 WC. 186 WC was carbo-thermally generated from a novel precursor synthesized from 186 WO 3 , aqueous ammonia and hexamethyltetramine. The inherent high electrical and thermal conductivity of this material, coupled with its high melting point, made it an ideal candidate for proton bombardment for production of 186 Re. An18 μA irradiation for 3h and processing via thermo-chromatography, 186 WC yielded 0.93mCi of 186g Re which corresponds to 89% of the calculated theoretical yields. The radiochemical purity of the desired 186g Re species was found to be between 95 and 97% with small contaminants of 186 ReO 2 . The radiochemistry utility of the product was investigated using S-benzoyl-MAG3, and 100% complexation was achieved with stability being maintained for 96h. The re-oxidation of 186 WC back to 186 WO 3 by oxygen in the thermo-chromatography method of processing ensured that the starting material was regenerated and recovered from the process in 94–98% yield.
Immobilized microorganisms for hydrogen and ammonia production

Abstract Biological hydrogen and ammonia production are currently being studied as a means of lessening the dependence on non-renewable resources. Some of the systems considered show additional potential in various waste treatment processes. As the systems currently being examined employ a variety of organisms and metabolic pathways, the energetics of the various modes of hydrogen and ammonia production are examined in detail. The use of immobilized microorganisms may offer some advantages over free-living cultures. The present status of the work in this field employing immobilized microorganisms is reviewed, and areas for future research and the potential impacts of this technology are discussed.
Asymptotics of convex sets in Euclidean and hyperbolic spaces

We study convex sets C of finite (but non-zero) volume in and . We show that the intersection C8 of any such set with the ideal boundary of has Minkowski (and thus Hausdorff) dimension of at most (n-1)/2, and this bound is sharp, at least in some dimensions n. We also show a sharp bound when C8 is a smooth submanifold of . In the hyperbolic case, we show that for any k(n-1)/2 there is a bounded section S of C through any prescribed point p, and we show an upper bound on the radius of the ball centered at p containing such a section. We show similar bounds for sections through the origin of a convex body in , and give asymptotic estimates as 1kn.
Optical-Optical Double Resonance Spectroscopy of the A-X and B-X Systems of Na3

$^{1}$ W.E. Ernst and S. Rakowsky, Phys. Rev. Lett. 74, 58 (1995). $^{2}$ W.E. Ernst and S. Rakowsky, Ber. Bunsenges. Phys. Chem. 99, 441 (1995). $^{3}$ H.-A. Eckel, J.M. Gress, J. Biele, and W. Demtr\""{o}der, J. Chem, Phys. 98, 135 (1993). $^{4}$ M. Meyer zur Heide, E. Tiemann, and D. Wendlandt, Chem. Phys. Lett. 199, 590 (1992).
Intratumoral hemorrhage among children with newly diagnosed, diffuse brainstem glioma.

BACKGROUND Children with diffuse brainstem glioma (BSG) commonly undergo novel therapies because their outcome is poor with radiation therapy (RT). Although recent clinical trials using new biologic agents documented intratumoral hemorrhage (IH) among several children with BSG, to the authors' knowledge little is known regarding this phenomenon. In the current study, the authors assessed the characteristics and estimated the cumulative incidence of IH among children with BSG. METHODS All available brain imaging studies and medical records of 48 consecutive patients with newly diagnosed BSG treated at the study institution over a 10-year interval (1992–2002) were reviewed. Treatment was comprised of RT and various regimens of conventional chemotherapy; none of these patients received biologic agents. At the time of last follow-up, all patients had died of tumor progression. RESULTS The authors reviewed 319 imaging studies (251 magnetic resonance imaging scans and 68 computed tomography scans). IH was present in 6.25% of patients at the time of diagnosis. The 6-month and 12-month cumulative incidence estimates of IH regardless of the associated symptoms were 15.5% ± 5.5% and 24.4% ± 6.5%, respectively. The same estimates for symptomatic cases were 8.9% ± 4% and 17.8% ± 6%, respectively. All cases of IH at the time of diagnosis and 78% of symptomatic cases that developed after diagnosis were located in necrotic areas. CONCLUSIONS Although IH is uncommon at the time of diagnosis, symptomatic IH may occur among nearly 20% of children after the diagnosis of BSG. The uniform occurrence of IH among patients treated with various chemotherapeutic regimens and its association with necrotic areas suggests that tumor biology plays a significant role in this event. Cancer 2006. © 2006 American Cancer Society.
Outcome of patients with hypertrophic cardiomyopathy and a normal electrocardiogram.

Objectives This study sought to clarify the frequency, clinical phenotype, and prognosis of those patients with hypertrophic cardiomyopathy (HCM) who present with a normal electrocardiogram (ECG). Background Hypertrophic cardiomyopathy is the most common cause of sudden death in young people. Screening advocates have recommended a 12-lead ECG for the early detection of HCM in athletes, yet the clinical outcomes of those presenting with a normal ECG remains to be fully delineated. Methods Baseline characteristic and echocardiographic data were collected on all patients with HCM who initially presented to our institution with a diagnostic echocardiogram but a normal ECG. Follow-up was obtained and compared with the prognosis of HCM patients who presented with abnormal ECGs. Results We compared 135 HCM patients with a normal ECG with 2,350 HCM patients with an abnormal ECG. The latter group was more likely to have worse symptoms, have higher gradients, and a greater degree of septal wall thickness than the patients with a normal ECG. Severe obstructive symptoms requiring surgical myectomy and implantation of an implantable cardioverter-defibrillator were more common in patients with abnormal ECGs. Cardiac survival was significantly better in the group with a normal ECG at presentation—none of these patients had a cardiac death at follow-up. Conclusions Almost 6% of patients presenting with demonstrable echocardiographic evidence of HCM had a normal ECG at the time of diagnosis. This subset of patients with normal ECG-HCM appears to exhibit a less severe phenotype with better cardiovascular outcomes.
Nucleosynthesis in massive stars and the 12C(α, γ)16O reaction rate

Abstract The evolution of a grid massive stars ranging from 12 to 40 M⊙ has been followed through all stages of nuclear burning up to the point of iron core collapse. The critical and highly uncertain rate for the reaction 12C(α, γ)16O has been varied over a range from 0.5 to 3.0 times that given by Caughlan and Fowler and two different prescriptions for semiconvection have been explored. The nucleosynthesis resulting from integrating the yields of these models over plausible initial stellar mass distributions is found to be in excellent agreement with the observed solar abundances of virtually all the intermediate mass isotopes (16 ≤ A ≤ 32) if, and only if, the rate of the 12C(α, γ)16O reaction is taken to be 1.7 ± 0.5 times that given by Caughlan and Fowler. This range is a small subset of what is allowed by current experimental measurements and can be taken as a nucleosynthetic “prediction” of the value that this rate needs to have in order to prevent 5- to 100-fold deviations from the observed relative abundances of key isotopes. These results are insensitive to the assumed slope of the initial stellar mass distribution within observational limits, and relatively insensitive to the theory of semiconvection (except for the apparent excessive production of 18O when semiconvective mixing is suppressed). Three of the stars have been followed through simulated explosions to obtain the explosive modifications to their nucleosynthesis (including the “neutrino process”), which for most isotopes is relatively small. Isotopic yields of both stable radioactive products are tabulated as are the calculated iron core masses of the presupernova stars.
Free-energy landscape for cage breaking of three hard disks

We investigate cage breaking in dense hard-disk systems using a model of three Brownian disks confined within a circular corral. This system has a six-dimensional configuration space, but can be equivalently thought to explore a symmetric one-dimensional free-energy landscape containing two energy minima separated by an energy barrier. The exact free-energy landscape can be calculated as a function of system size by a direct enumeration of states. Results of simulations show the average time between cage breaking events follows an Arrhenius scaling when the energy barrier is large. We also discuss some of the consequences of using a one-dimensional representation to understand dynamics through a multidimensional space, such as diffusion acquiring spatial dependence and discontinuities in spatial derivatives of free energy.
Collecting relevance feedback on titles and photographs in weblog posts

We investigate new interfaces that allow users to specify topics of interest in streams of weblog stories by providing relevance feedback to a search algorithm. Noting that weblog stories often contain photographs taken by the blogger during the course of the narrated events, we investigate whether these photographs can serve as a proxy for the whole post when users are making judgments as to the post's relevance. We developed a new story annotation interface for collecting relevance feedback with three variations: users are presented either with the full post as it appears in a weblog, an embedded photograph, or only the title of the post. We describe a user evaluation that compares annotation time, quality, and subjective user experience across each of these three conditions. The results show that relevance judgments based on embedded photographs or titles are far less accurate than when reading the whole weblog post, but the time required to acquire an accurate model of the user's topic interest is greatly reduced.
Surgical site infections after pediatric intracranial surgery for craniofacial malformations: frequency and risk factors.

Objective Surgical site infections (SSIs) after pediatric intracranial surgery for craniofacial malformations are relatively common and potentially serious nosocomial infections. Despite this, few studies have been published on this topic. We performed a retrospective study to determine the incidence of and factors associated with SSIs after intracranial surgery for craniofacial malformations at a single multidisciplinary craniofacial center during a 6-year period. Methods Retrospective chart review was performed on 254 patients who underwent 281 intracranial procedures during a 6-year period. Patients with SSIs (cases) were compared with those without SSIs (controls). National Nosocomial Infection Surveillance System criteria were used to identify cases of SSI. Results SSIs occurred in 9 (3.2%) of 281 intracranial procedures that took place during the study period. Factors associated with an SSI included a complicated diagnosis comprising a diagnosis of syndromic craniosynostosis, frontonasal dysplasia, or oblique facial cleft (odds ratio [OR], 13.0; 95% confidence interval [CI], 2.6-64.4); duration of surgery longer than 426 minutes (OR, 12.1; 95% CI, 2.4-59.9); closure of skin under tension (OR, 12.5; 95% CI, 3.0-52.6); use of bovine pericardium (OR and 95% CI undefined); more than four surgeons present during surgery (OR, 6.3; 95% CI, 1.2-32); pediatric intensive care unit stay longer than 2 days (OR, 10.8; 95% CI, 2.2-53.3); and use of a ventilator after surgery (OR, 4.8; 95% CI, 1.2-18.6). Conclusion In this study, the presence of a complicated diagnosis and a number of other factors were associated with an SSI after pediatric intracranial surgery for craniofacial malformations. We speculate that a complicated diagnosis may be a marker for other factors that contribute to the risk of an SSI. Future studies investigating SSIs after intracranial surgery should consider these factors.
Multidimensional simulation and optimization of hybrid laser and discharge plasma devices for EUV lithography

Current devices for EUV lithography combine both laser and discharge physics to achieve sufficient brightness with minimum debris generation to support the throughput requirements of High-Volume Manufacturing (HVM) lithography exposure tools with long lifetime. Source performance, Debris mitigation, and reflector system are critical to efficient EUV collection and component lifetime. Integrated models are developed to simulate EUV emission at high power and debris generation and transport in hybrid EUV devices. The models being developed include, for example, new ideas and parameters of laser beams in discharge devices. In addition, optimization of source parameters, combination magnetic fields and gas jet parameters to significantly reduce the debris, and mirror surface conditions to enhance the reflectivity of EUV. Source optimization studies include full 3-D simulation of laser interaction with tin targets followed by discharge simulation to produce the optimum EUV photons. Initial simulations show that for HVM devices a combination of source optimization, innovative debris mitigation system, and understanding debris/mirror interaction is required to achieve the lifetime needed.
Measurement of breast tissue composition with dual energy cone-beam computed tomography: A postmortem study

Purpose: To investigate the feasibility of a three-material compositional measurement of water, lipid, and protein content of breast tissue with dual kVp cone-beam computed tomography (CT) for diagnostic purposes. Methods: Simulations were performed on a flat panel-based computed tomography system with a dual kVp technique in order to guide the selection of experimental acquisition parameters. The expected errors induced by using the proposed calibration materials were also estimated by simulation. Twenty pairs of postmortem breast samples were imaged with a flat-panel based dual kVp cone-beam CT system, followed by image-based material decomposition using calibration data obtained from a three-material phantom consisting of water, vegetable oil, and polyoxymethylene plastic. The tissue samples were then chemically decomposed into their respective water, lipid, and protein contents after imaging to allow direct comparison with data from dual energy decomposition. Results: Guided by results from simulation, the beam energies for the dual kVp cone-beam CT system were selected to be 50 and 120 kVp with the mean glandular dose divided equally between each exposure. The simulation also suggested that the use of polyoxymethylene as the calibration material for the measurement of pure protein may introduce an error of −11.0%. However, the tissue decomposition experiments, which employed a calibration phantom made out of water, oil, and polyoxymethylene, exhibited strong correlation with data from the chemical analysis. The average root-mean-square percentage error for water, lipid, and protein contents was 3.58% as compared with chemical analysis. Conclusions: The results of this study suggest that the water, lipid, and protein contents can be accurately measured using dual kVp cone-beam CT. The tissue compositional information may improve the sensitivity and specificity for breast cancer diagnosis.
On the nature of the anti-tail of Comet Kohoutek (1973f) I. A working model

The model derived for the anti-tail of Comet Kohoutek describes it as a flat formation, confined essentially to the comet's orbit plane and composed of relatively heavy particles (mostly in the size range 0.1-1 mm) whose motions are controlled by solar gravity and solar radiation pressure. Almost all the material was produced by the comet before perihelion at a rate about an order of magnitude higher than for Comets Arend-Roland and Bennett. The latent heat of vaporization of the particle material is estimated at 40-45 kcal/mole or higher.
Critical factors influencing the fire performance of bolted double angle connections

Abstract Double angle connections are frequently used in steel framed structures and these connections, during a fire incident, play a critical role in transferring forces between structural members. There is lack of understanding on the response of bolted double angle connections under fire conditions. In this paper results from a set of numerical studies, carried out using finite element program ANSYS, on the fire behavior of bolted double angle connections are presented. In the analysis material and geometric nonlinearities, high temperature properties of steel and nonlinear contact interactions, are accounted for. The model is validated by comparing the predictions from the analysis with the published experimental results. The validated model was applied to carry out parametric studies to quantify the effect of critical factors on the fire performance of bolted double angle connections. Results from the parametric studies indicate that bolt-hole size, edge-distance, thermal gradient and slenderness of beam web have significant influence on the fire performance of bolted double angle connections.
Fiber optic two-photon fluorescence microendoscopy: towards brain imaging in freely moving mice

We introduce a compact and lightweight (3.7 g) two-photon fluorescence microendoscope, which is based on a flexible photonic bandgap fiber and a DC micromotor, and which is designed for brain imaging in freely moving mice.
Spatial Heterogeneity in Cancer Control Planning and Cancer Screening Behavior.

Each state is autonomous in its comprehensive cancer control (CCC) program, and considerable heterogeneity exists in the program plans, but researchers often focus on the concept of nationally repr...
Selection is more intelligent than design: improving the affinity of a bivalent ligand through directed evolution

Multivalent molecular interactions can be exploited to dramatically enhance the performance of an affinity reagent. The enhancement in affinity and specificity achieved with a multivalent construct depends critically on the effectiveness of the scaffold that joins the ligands, as this determines their positions and orientations with respect to the target molecule. Currently, no generalizable design rules exist for construction of an optimal multivalent ligand for targets with known structures, and the design challenge remains an insurmountable obstacle for the large number of proteins whose structures are not known. As an alternative to such design-based strategies, we report here a directed evolution-based method for generating optimal bivalent aptamers. To demonstrate this approach, we fused two thrombin aptamers with a randomized DNA sequence and used a microfluidic in vitro selection strategy to isolate scaffolds with exceptionally high affinities. Within five rounds of selection, we generated a bivalent aptamer that binds thrombin with an apparent dissociation constant (K(d)) <10 pM, representing a ∼200-fold improvement in binding affinity over the monomeric aptamers and a ∼15-fold improvement over the best designed bivalent construct. The process described here can be used to produce high-affinity multivalent aptamers and could potentially be adapted to other classes of biomolecules.
Analysis of the t(2;5) (p23;q35) Translocation in CD30+ Primary Cutaneous Lymphoproliferative Disorders and Hodgkin's Disease

The t(2;5) (p23;q35) chromosomal translocation is found in about 40% of lymph node-based CD30+ anaplastic large cell lymphomas of T-cell or null-cell lineage. This translocation results in the expression of a fusion protein containing the catalytic domain of anaplastic lymphoma kinase (ALK) under the control of the promoter for nucleophosmin (NPM), a nucleolar phosphoprotein. Expression of ALK activity, normally absent in lymphocytes, is postulated to be involved in the pathogenesis of lymphomas bearing the t(2;5) translocation. Certain primary cutaneous lymphoproliferative disorders and Hodgkin's disease are also known to contain CD30+ large lymphoid cells. In order to determine the role of the t(2;5) translocation in these diseases, several investigators have employed a variety of techniques including cytogenetics, genomic Southern blot analysis, RNA- and DNA-based PCR assays, various forms of in-situ hybridization, and immunostaining for the p80 fusion protein encoded by the chimeric t(2;5) transcripts. These studies included approximately 415 cases of Hodgkin's disease, 65 cases of CD30+ primary cutaneous large cell lymphoma, and 38 cases of lymphomatoid papulosis. The aggregate results of these studies indicate that the t(2;5) translocation or other somatic mutations resulting in inappropriate expression of ALK are involved rarely if at all in the pathogenesis of Hodgkin's disease, but may be present in about 10% of cases of lymphomatoid papulosis and 20% of cases of CD30+ primary cutaneous large cell lymphoma. However, the t(2;5) has not been detected yet in any case involving multiple or secondary CD30+ lymphoproliferative disorders, thereby providing no evidence for a role in tumor clone progression. Additional studies will be needed to determine if t(2;5) status has any clinical significance for patients with CD30+ primary cutaneous lymphoproliferative disorders.
The Visual Deprivation Syndrome

The variety of experimental manipulations shown to induce amblyopia in young cats and monkeys is described. A brief monocular eye closure of only one week or an artificial strabismus of only two weeks produces profound long-lasting changes in the electrophysiology and anatomy of the visual system. A poor quality of visual experience, an image imbalance between the two eyes, or any spatial or temporal incompatibility can produce these symptoms of amblyopia.
Quadrature mirror filter banks, M-band extensions and perfect-reconstruction techniques

In this paper, quadrature mirror filters (QMF) are reviewed. After a brief introduction to multirate building blocks, the two-band QMF bank is discussed. Various distortions caused by the structure, and methods to eliminate these distortions are outlined. Perfect-reconstruction structures for the two-band case are reviewed, and the results are extended to the case of arbitrary number of channels. The relation between perfect-reconstruction QMF banks and the concept of losslessness in transfers-matrices is indicated. New lattice structures are presented, which perform the perfect reconstruction, sometimes even under coefficient quantization.
Analysis of a Stitched Double Cantilever Beam

A simple analytical model is presented to describe crack propagation in stitched laminated Double Cantilever Beam (DCB) specimens. The stitches are smeared and modeled as continuous cohesive springs, which are assumed to be linear-elastic until final failure. Timoshenko beam theory is used to model the DCB specimen. As the specimen is loaded, the stitches are assumed to break when the strain in the stitches reaches the ultimate strain. The crack tip is assumed to advance as the energy release rate at the crack tip reaches the Mode I fracture toughness of the parent laminate. A closed form solution is obtained for the problem of beam on elastic foundation and it is used to simulate the DCB test and crack propagation. Results presented include, load-deflection diagrams, crack bridging length and apparent fracture toughness for various stitch parameters. A semi-empirical formula is derived for the bridging length as a function of the stitch ultimate strain and fracture toughness ofthe parent laminate. The results are compared with experimental results. It is found that, for the case with Kevlar stitches, the linear elastic model of the stitch yarn is not adequate. It is shown that inelastic behavior ofthe stitches plays a significant role in increasing the fracture toughness due to stitching.
Readable Formal Proofs

The need to integrate the processes of programming and program verification requires notations for formal proofs that are easily readable. We discuss this problem in the context of Hoare logic and separation logic. It has long been the custom to describe formal proofs in these logics informally by means of "annotated specifications" or "proof outlines". For simple programs, these annotated specifications are essentially similar to the annotated flow charts introduced by Floyd and Naur. For more elaborate programs, a richer notation has evolved for dealing with procedure calls and various structural rules, such as the frame axiom, as well as various rules for concurrency. Our goal is to devise a formalism for insuring that annotated specifications actually determine valid formal proofs (modulo the correctness of verification conditions), while providing as much flexibility as possible. For this purpose, we give inference rules for "annotation definitions" that assert that an annotated specification determines a particular Hoare triple. We consider verification algorithms in a wide sense. The outcome of a verification algorithm can be a definite (yes or no) answer, a "don't know" answer, or a conditional answer or no answer at all (divergence). We obtain these kinds of verification algorithms if we apply the existing technology of abstraction to least-fixpoint checking, i.e., checking whether the least fixpoint of a given operator in a given lattice is smaller than a given bound. The formulation of the verification algorithm as least-fixpoint checking is classical for the class of correctness properties that are reducible to non-reachability (validity of assertions, partial correctness, safety properties). We need to investigate the approach also for the class of correctness properties that are reducible to termination (validity of intermittent assertions, total correctness, liveness properties), for all classes of programs including procedural (recursive) programs and concurrent programs.
Parametric uncertainty modeling for LFT model realization

This paper presents a procedure for parametric uncertainty modeling of a small unmanned aerial vehicle flight dynamics for the purpose of LFT model realization. Experimental data measurements were taken to construct the parametric uncertainties in the 6-DOF nonlinear simulation model for the vehicle . A new approach is used to linearize the uncertain nonlinear simulation model developed and a physically meaningful LFT model was obtained. The accuracy and exactness of this approach was benchmark against the original uncertain nonlinear simulation model with uncertainty perturbations.
The Platycerus (Coleoptera, Lucanidae) of California, with the recognition of Platycerus cribripennis Van Dyke as a valid species

Th e status of Platycerus cribripennis Van Dyke, generally treated as a synonym of P. marginalis Casey, has been unclear. Here we recognize and redescribe P. cribripennis, which is endemic to the coastal mountains of California, as a valid species due to its unique morphology. A key to the Platycerus of California is presented, and the distributions of the recognized species are discussed.
Smoothing splines with boundary correction

Regular smoothing splines are known to have a type of boundary bias problem that can reduce their estimation efficiency. In this paper, a boundary corrected smoothing spline with general order is designed in a way that the risk will decay at an optimal rate. An O(n) algorithm is also developed to compute the resultant estimator efficiently.
A New Method for Estimating Enzyme Activity and Control Coefficients in vivo

An understanding of metabolism in vivo must, of course, be based upon a systems analysis that includes an examination of the role and relationships of all the variables involved. These include the concentrations of substrates, products, and effectors as well as enzyme kinetic mechanisms, constants and enzyme activity. Current research in areas such as biochemical differentiation, aging, biotechnology, etc., is focussed primarily on the regulation of metabolism by enzyme activity. In fact, metabolites are generally more important than enzymes in controlling reaction rates. As we shall be discussing the citric acid cycle it is appropriate to quote Krebs (1957): “The average half-life of the acids in the tricarboxylic acid cycle ... is a few seconds. The amounts of enzyme in the tissue are sufficient to deal with the intermediates as soon as they arise: in other words, the amount of available substrate is the factor limiting the rate at which the intermediary step proceeds.” And yet, the recent literature on metabolic regulation in vivo describes the role of metabolites by such passive and mysterious words as “elasticity,” while enzymes are given credit as the force behind “control coefficients.” Reactions are often referred to by the name of the enzyme catalyst, and the rate of a reaction in vivo is often equated with the activity of the enzyme. Some of this prejudice stems from in vitro studies, in which enzymes must be diluted to the point at which they limit the rate of the reaction being measured, while substrates must be present at levels greatly exceeding their in vivo concentration.
Can we successfully maintain risk patients

: The most fundamental premise in the current view of periodontal disease is that not all individuals are at equal risk for disease and disease progression. Studies reveal that about 5–20% of the population is at risk for severe disease progression. The purpose of this paper is to define at-risk patients, review risk factors and indicators of disease progression, and outline an evidence-based strategy that includes both self-care and professional care for maintaining periodontal health. Risk factors/risk indicators considered include history of previous disease, increased pocket depth and loss of clinical attachment, frequency of dental care, specific bacterial pathogens, and systemic/environmental host factors such as smoking, diabetes mellitus, genetics, and stress. Because host factors may have more influence on disease progression than periodontal pathogens, personal and professional maintenance care must include the role of the host in periodontal disease progression. By examining the evidence surrounding these complex issues, dentists and dental hygienists are able to determine the extent to which evidence supports available approaches to maintain periodontal health and control disease progression.
A COMPOSITES THEORY PREDICTS THE DEPENDENCE OF STIFFNESS OF CARTILAGE CULTURE TISSUES ON COLLAGEN VOLUME FRACTION

Abstract The tensile stiffness of tissue grown from chondrocyte culture was both measured experimentally and predicted using a composites model theory relating tissue microstructure to macroscopic material stiffness. The tissue was altered by several treatment protocols to provide a wide range of collagen fibril volume fraction (0.015–0.15). The rate of change of tissue modulus with change in collegen volume fraction predicted by the theory was within 14% of the slope of the linear fit through the experimental data, without the use of fitting parameters for the theoretical value of the slope. Use of the model to simulate cytokine mediated tissue digestion suggests that the action of IL-1 β and retinoic acid is mainly removal of proteoglycans and some removal of collagen. The model also indicates that the matrix and collagen remaining in the tissue has the same elastic properties as the untreated tissue, and is not damaged due to the alteration. Young’s modulus of the collagen fibrils is predicted to be 120 MPa, a value in the range of previous studies. This value is dependent mainly on the matrix modulus and collagen fibril volume fraction and not on Poisson’s ratio of either matrix or fibril. Poisson’s ratio of the tissue depends primarily on the Poisson’s ratio of the matrix.