cssi/SciSciGPT-SciSciNet huggingface dataset:
Modeling thermography of the tumorous human breast: From forward problem to inverse problem solving

The abnormal thermogram has been shown to be a reliable indicator of a high risk of breast cancer. Nevertheless, a major weakness of current infrared breast thermography is its poor sensitivity for deeper tumors. Numerical modeling for breast thermography provides an effective tool to investigate the complex relationships between the breast thermal behaviors and the underlying pathophysiological conditions. Conventional “forward problem” modeling cannot be used to directly improve the tumor detectability, however, because the underlying tissue thermal properties are generally unknown. Based on our new comprehensive forward modeling, we propose an “inverse problem” modeling technique that aims to estimate tissue thermal properties from the breast surface thermogram. Our data suggest that the estimation of tumor-induced thermal contrast can be significantly improved by using the proposed inverse problem solving techniques to provide the individual-specific thermal background, especially for deeper tumors.
Strategy for automated analysis of dynamic metabolic mixtures by NMR. Application to an insect venom.

Elucidation of the composition of chemical−biological samples is a main focus of systems biology and metabolomics. Due to the inherent complexity of these mixtures, reliable, efficient, and potentially automatable methods are needed to identify the underlying metabolites and natural products. Because of its rich chemical information content, nuclear magnetic resonance (NMR) spectroscopy has a unique potential for this task. Here we present a generalization and application of a recently introduced NMR data collection, processing, and analysis strategy that circumvents the need for extensive purification and hyphenation prior to analysis. It uses covariance TOCSY NMR spectra measured on a 1-mm high-temperature cryogenic probe that are analyzed by a spectral trace clustering algorithm yielding 1D NMR spectra of the individual components for their unambiguous identification. The method is demonstrated on a metabolic model mixture and is then applied to the unpurified venom mixture of an individual walking sti...
Citrate formation by rat lung mitochondrial preparations.

Abstract Rat lung mitochondrial preparations were incubated in the presence of pyruvate and malate. The principal metabolic products measured were citrate and CO 2 . Citrate formation from pyruvate was found to be dependent on the presence of malate. Significant citrate was formed in the presence of isocitrate and the rate of citrate formation was increased by the addition of pyruvate. Small amounts of citrate were formed by lung mitochondrial preparations in the presence of 2-oxoglutarate and succinate only after the addition of pyruvate. The level of acetyl-CoA was significantly greater in the presence of pyruvate than in the presence of pyruvate plus malate. The addition of malate to lung mitochondrial preparations increased 14 CO 2 production from [U- 14 C]- and [1- 14 C] pyruvate but decreased its production from [2- 14 C]- and [3- 14 C]-pyruvate. However, malate increased the incorporation of [2- 14 C] pyruvate into malate and citrate. A low level of pyruvate-dependent H 14 CO 8 -incorporation into acid-stable products was observed, principally citrate and malate, but this rate did not exceed 5% of the rate of net citrate formation in the presence of malate and pyruvate. The capacity of rat lung mitochondria to form oxaloacetate from pyruvate alone in vitro is very limited, and would appear to cast doubt on a major role of pyruvate carboxylase in citrate formation. It is concluded that the rate of citrate formation from pyruvate is limited by the availability of intramitochondrial oxaloacetate and the rate of citrate efflux across the mitochondrial membrane.
Blood supply of the human fetal mandible.

Gross anatomic and radiologic studies of the blood supply to the human mandible of the full-term fetus and newborn infant were performed on 22 specimens ranging from 320–538 mm crown-heel length and 1,192–4,108 gm in weight. Ten specimens were injected with red-lead and liquid soap to demonstrate the arteries radiographically. Twelve other specimens were injected with Castolite with a sprinkling of red-lead and yellow dye. The best side of each specimen was studied by radiography and dissection. This study demonstrated: (1) a masseteric arterial plexus supplying the coronoid process and the lateral wall of the ramus with contributions from the facial, masseter, transverse facial and external carotid arteries or combinations thereof; (2) a mental arterial plexus anastomosing with the mental, submental and inferior labial arteries; (3) an inferior alveolar artery supplying most of the body of the mandible with a majority of its branches passing in an upward direction; and (4) periosteal vessels supplying the lower border of the mandible and receiving their blood supply from the blood vessels supplying the muscles attaching to these areas and the periosteum. Supplemental to the above findings were anastomoses between the submental, mylohyoid and sublingual arteries along the medial border of the mandible. Also a significant variation not previously recorded was noted in one specimen in which the sublingual artery originated from the facial artery rather than the lingual.
Aldosterone in congestive heart failure

The potent mineralocorticoid aldosterone has a multifaceted role in the pathogenesis of congestive heart failure. In addition to its contribution to salt and water retention, it also promotes organ fibrosis. Although angiotensin-converting–enzyme inhibitors have important therapeutic benefit in heart failure, they do not eliminate the effects of aldosterone. Thus, recent studies have underscored the value of aldosterone-receptor antagonists, such as spironolactone, in the treatment of chronic heart failure. This review article gives an in-depth update on the mechanisms of action of aldosterone and their implications for therapy.
Ordered conjugated polymer nano- and microstructures: Structure control for improved performance of organic electronics

Summary Conjugated polymers (CPs), containing conjugated chains with π-electrons delocalized along the polymer backbone, have numerous potential applications in solution processed organic electronics. The charge transport mechanism of CPs and anisotropic charge transport characteristics in organic electronics require the control of CP structures at intra-molecular, inter-molecular and inter-grain level. This review focuses on the technologies that grant the control of the structure and orientation of CP crystal structures, especially the approaches of using graphitic surfaces to guide the crystallization of CPs, and provides an insight into the impact of the orientation of CP nano- and microstructures on CP-based organic electronics such as field-effect-transistors and organic photovoltaics.
HFE C282Y homozygotes have reduced low-density lipoprotein cholesterol: the Atherosclerosis Risk in Communities (ARIC) Study

Recent studies have raised questions about the long-term health risks for individuals with mutations in the HFE gene, although previous studies may have been plagued by selection bias or lack of population-based comparison groups. We examined cardiovascular disease risk factors and iron and liver biomarkers, as well as morbidity and mortality associated with the C282Y and H63D variants of HFE in the Atherosclerosis Risk in Communities (ARIC) study, which is a population-based cohort of nearly 16,000 U.S. white and black men and women who were 45-64 years old at baseline. Subjects were followed for an average of 15 years for death, incident coronary heart disease, stroke, and heart failure, and an average of 8 years for incident diabetes. The prevalence of C282Y homozygosity was 0.42% (45/10,800) in whites, which is similar to other North American population-based studies. C282Y homozygotes had significantly lower mean low-density lipoprotein (LDL) cholesterol and fibrinogen as well as higher mean levels of iron (ferritin, transferrin saturation) and liver biomarkers (alanine aminotransferase, Hepascore) compared with HFE wild-type subjects. Rates of all-cause mortality, cardiovascular disease, and diabetes were similar across HFE genotypes. These prospective, population-based data indicate higher serum iron indices and possible mild liver dysfunction or disease in some C282Y homozygotes, but they provide little evidence that HFE C282Y or H63D mutations are related to all-cause mortality, cardiovascular disease, or diabetes. Reduced LDL in C282Y homozygotes may be because of effects of excess iron on cholesterol metabolism and lipoprotein formation in the liver.
The International Effects of U.S. Farm Subsidies

Using dynamic programming, this paper examines effects of farm subsidies on U.S. exports of corn, cotton, rice, and wheat. The six policy simulations described here explore alternative proposals in the current round of the General Agreement on Tariffs and Trade. The analysis leads to two conclusions. First, abolishing domestic subsidies lowers world prices of these crops. Second, imposing tighter supply controls may not actually decrease exports in the short run.
A numerical model coupling the heat and gas species' transport processes in a tubular SOFC

A numerical model is presented in this work that computes the interdependent fields of flow, temperature, and mass fractions in a single tubular solid oxide fuel cell (SOFC). Fuel gas from a pre-reformer is considered to contain H 2 , CO, CO 2 , H 2 O (vapor), and CH 4 , so reforming and shift reactions in the cell are incorporated. The model uses mixture gas properties of the fuel and oxidant that are functions of the numerically obtained local temperature, pressure, and species concentrations, which are both interdependent and related to the chemical and electrochemical reactions. A discretized network circuit of a tubular SOFC was adopted to account for the Ohmic losses and Joule heating from the current passing around the circumference of the cell to the interconnect. In the iterative computation, local electrochemical parameters were simultaneously calculated based on the local parameters of pressure, temperature, and concentration of the species. Upon convergence of the computation, both local details and the overall performance of the fuel cell are obtained. These numerical results are important in order to better understand the operation of SOFCs.
Training dynamics and neural network performance

Abstract We use an analysis of a simple model of recurrent network dynamics to gain qualitative insights into the training dynamics of feedforward multilayer perceptrons (MLPs) used for classification. These insights suggest changes to the training methods used for MLPs that improve network performance significantly. In previous work, the probabilistic neural network (PNN) was shown to provide better zero-reject error performance on character and fingerprint classification problems than radial basis function and MLP-based neural network methods. We will show that performance equal to or better than PNN can be achieved with a single three-layer MLP by making fundamental changes in the network optimization strategy. These changes are: 1) use of neuron activation functions, which reduce the probability of singular Jacobians; 2) use of successive regularization to constrain the volume of the minimized weight space; 3) use of Boltzmann pruning to constrain the dimension of the weight space; 4) use of Prior class probabilities to normalize all error calculations, so that statistically significant samples of rare but important classes can be included without distorting the error surface. All four of these changes are made in the inner loop of a conjugate gradient optimization iteration and are intended to simplify the training dynamics of the optimization. On handprinted digits and fingerprint classification problems these modifications improve error-reject performance by factors between 2 and 4, and reduce network size by 40–60%. © 1997 Elsevier Science Ltd.
Negative ion fast atom bombardment mass spectrometry of isoprenoid diphosphates and related analogs

Abstract Negative ion fast atom bombardment mass spectrometry (FABMS) was used to obtain mass spectra of the naturally occurring isoprenoid metabolites isopentenyl diphosphate ( 1 ), dimethylallyl diphosphate ( 5 ), geranyl diphosphate ( 3 ), farnesyl diphosphate ( 6 ), and presqualene diphosphate ( 8 ). Mass spectra were also recorded for several synthetic analogs, including methylene-bridged diphosphonates 9 and 10 , bisdiphosphates 12–14 , and nitrogen-containing analogs 15–18 . The ammonium salts of these materials gave molecular ions at [M-H] − for the acid forms (M) of the diphosphate esters. Spectra of the sodium salts of isopentenyl diphosphate ( 1 ) and geranyl diphosphate ( 3 ) showed predominant peaks at m z 267 [M + Na-2H] − and 335 [M + Na-2H] − , respectively, along with several diagnostic fragment ions at m z 177 (H 3 P 2 O 7 ), 159 (HP 2 O 6 ), and 97 (H 2 PO 4 ) from the diphosphate moiety. The molecular ion of isopentenyl diphosphate ( 1 ) ( m z 245) was readily observed with 4 μg of compound. Thus, detection at the microgram level should be possible for disphosphates whose molecular ions do not overlap with peaks from the matrix. These studies indicate that negative ion FABMS will be useful for the analysis of isoprenoid diphosphate intermediates in biosynthetic and enzyme mechanism studies.
Green−Kubo Formulas for Mutual Diffusion Coefficients in Multicomponent Systems

Green−Kubo relations for the mutual diffusion coefficients of an n-component system are derived from hydrodynamic equations, linear response theory, and the statistical theory of fluctuations. The mutual diffusion coefficients, which form an (n − 1)-dimensional matrix, are formulated as a product of a kinetic matrix and a thermodynamic matrix. The kinetic matrix consists of time integrals of diffusion flux correlation functions, i.e., the Onsager phenomenological coefficients. The thermodynamic matrix is determined by spatial integrals of radial distribution functions. The formulas are derived initially in the barycentric reference frame and then transformed to the volume-fixed reference frame, which is more appropriate to laboratory studies. Explicit expressions for binary and ternary mixtures are presented, from which various empirical relations between the mutual diffusion coefficients and self-diffusion coefficients are obtained using particular assumptions regarding the velocity cross-correlation fun...
Lung Cancer Diagnostic and Treatment Intervals in the United States: A Health Care Disparity?

Introduction Lung cancer diagnostic and treatment delays have been described for several patient populations. However, few studies have analyzed these intervals among patients treated in contemporary health care systems in the United States. We therefore studied the timing of lung cancer diagnosis and treatment at a U.S. medical center providing care to a diverse patient population within two different hospital systems. Methods We performed a retrospective analysis of consecutive patients diagnosed with non-small cell lung cancer stage I to III from 2000 to 2005 at public and private hospitals affiliated with the University of Texas Southwestern Medical Center. We recorded patient and disease characteristics; dates of initial radiograph suspicious for lung cancer, diagnosis, and treatment; and overall survival. Associations between these factors were assessed using univariate analysis, multivariate logistic regression, and Kaplan-Meier survival analysis. Results A total of 482 patients met criteria for analysis. In univariate analyses, the image-treatment interval was significantly associated with race, age, income, insurance type, and hospital type (76 days for public versus 45 days for private; p p p = 0.27) or with survival ( p = 0.42). Conclusion Intervals between suspicion, diagnosis, and treatment of lung cancer vary widely among patients. Health care system factors, such as hospital type, largely account for these discrepancies. In this study, these intervals do not appear to be associated with clinical outcomes.
Cu2ZnSnS4 solar cells fabricated by short-term sulfurization of sputtered Sn/Zn/Cu precursors under an H2S atmosphere

Abstract Synthesis of Cu2ZnSnS4 (CZTS) thin films by short-term sulfurization of sputtered Sn/Zn/Cu precursors under ambient H2S is studied. The effect of the sulfurization processes on the film morphology, surface roughness, composition of the CZTS, and the crystallinity was investigated by using scanning electron microscopy, optical profiler, energy dispersive spectroscopy, and X-ray diffraction respectively. To further explore the CZTS layer, the following additional layers were deposited to complete the solar cells: CdS with chemical bath deposition; ZnO and Al2O3-doped ZnO with RF magnetron deposition; and, silver fingers as the front contact as the last layer. The optical and morphological properties of the CZTS films were investigated and compared. Subsequently, the electrical characteristics and the efficiencies of the regarding solar cells were analyzed. A maximum efficiency of 3.8% has been obtained for the fast sulfurization (30 min at 580 °C) and finally, the performance is compared with our best cell fabricated through the more common slow annealing.
Why alpha-antiplasmin must be converted to a derivative form for optimal function.

Summary. Background: Human α2-antiplasmin (α2AP), the primary inhibitor of fibrinolysis, is secreted from the liver into plasma as a 464-residue protein with Met as the N-terminus. An R6W polymorphism has been suggested to affect fibrinolytic rate. Within circulating blood, antiplasmin-cleaving enzyme (APCE) cleaves Met-α2AP(R6) faster than Met-α2AP(W6) at the Pro12–Asn13 bond to yield Asn-α2AP. Objectives: To compare Met-α2AP(R6), Met-α2AP(W6) and Asn-α2AP for crosslinking with fibrin and the ability to protect fibrin from digestion by plasmin. Methods and results: Asn-α2AP utilizes Gln2 (Gln14 in Met-α2AP) to become crosslinked to fibrin approximately twelvefold faster than Met-α2AP(R6) or Met-α2AP(W6), and this enhances the resistance of fibrin to plasmin. All three forms of α2AP inhibit plasmin at identical rates. The N-terminal 12-residue peptide of Met-α2AP slows crosslinking of Met-α2AP(R6) or Met-α2AP(W6) by limiting access of factor XIIIa to Gln14 rather than shifting crosslinking to other Gln residues. Edman sequencing and mass analyses of tryptic peptides from each α2AP crosslinked with 5-(biotinamido)pentylamine showed Gln14 as the only major crosslinking site. Residues 5–8, GRQL in Met-α2AP(R6), and residues 1–8, MEPLGWQL in Met-α2AP(W6), slow fibrin crosslinking. Conclusion: Gln14 in both Met-α2AP(R6) and Met-α2AP(W6) is sheltered by the N-terminal 12-residue peptide, which, when cleaved, yields Asn-α2AP, which is rapidly crosslinked to fibrin and maximally protects it from plasmin. The R6 W polymorphism in Met-α2AP does not affect its crosslinking to fibrin, but it does slow cleavage by APCE and reduces the amount of Asn-α2AP available for rapid crosslinking to fibrin.
Intrinsic Activation Barriers as a Guide to Mechanisms of Reactions in the Gas Phase and on Solid Surfaces

Abstract This paper shows that a simple heuristic, that the intrinsic barriers for C–C and C–O bond scission is 20–40 kcal/mole higher than the intrinsic barriers for C–H bond scission, provides useful insights into reactions on surfaces. Quantum mechanical calculations at various levels up to QCISD(T)/6-311G(d,p) are used to show that the gas-phase intrinsic barrier for dehydrogenation reactions of the form ·H+CH3CH2R → H2+·CH2CH2R are 33 ± 2 kcal/mole less than the intrinsic barriers for hydrogenolysis reactions of the form ·H+CH3CH2R → CH4+·CH2R with R groups comprising a wide range of Taft parameters. We thenassumethat the difference in intrinsic barriers is the same, in the gas phase and on a surface, and use that assumption to predict mechanisms of reactions on metal surfaces. We find quite good agreement with the experiment for a wide variety of systems. In particular we explain why most hydrocarbon decomposition processes go via sequential decomposition mechanisms. We also explain why hydrogenolysis reactions have much higher activation barriers than most hydrogenation/dehydrogenation reactions on transition metal surfaces. These results imply that an examination of intrinsic barriers may provide a wide framework to characterize many types of surface reactions.
Remote sensing of NO using a differential absorption lidar

Single-ended remote sensing measurements of atmospheric NO have been made using differential absorption of frequency-doubled pulsed CO2 laser radiation backscattered from topographic targets. Returns were obtained from targets at ranges out to 1.4 km, and significant NO concentrations above ambient were observed over a path which crossed a traffic roadway at a range of 0.5 km. In view of the severe atmospheric water vapor absorption in the spectral region containing the NO absorption band, the range dependence of the lidar returns was also measured in order to determine the differential absorption of the ambient atmosphere. The results differed significantly from those computed from atmospheric transmission data tapes.
Quality measurement : Who is measuring outcomes and what are patients being told?

Change is inevitable, but participation is optional. An array of quality measures is being used by various government entities, health care purchasers and payers, and other groups. Many of the quality-measurement initiatives have not only gained the attention of large employers, but are also beginning to pique the public's interest. Novel approaches to measuring and rewarding quality are also emerging, such as pay-for-performance schemes and the use of APR-DRGs. Health care organizations that participate in the quality-measurement process and provide input will benefit by the type of measures that are ultimately created. It is much better to be part of the development process than to have insurer- or employer-designed quality measures imposed on your institution. At the very least, health care organizations would be wise to serve as watchdogs to ensure that currently proposed quality measures truly measure high-quality care.
Linking cranial kinematics, buccal pressure, and suction feeding performance in largemouth bass.

Abstract The rate and magnitude of buccal expansion are thought to determine the pattern of water flow and the change in buccal pressure during suction feeding. Feeding events that generate higher flow rates should induce stronger suction pressure and allow predators to draw prey from further away. We tested these expectations by measuring the effects of prey capture kinematics on suction pressure and the effects of the latter on the distance from which prey were drawn—termed suction distance. We simultaneously, but not synchronously, recorded 500‐Hz video and buccal pressure from 199 sequences of four largemouth bass, Micropterus salmoides, feeding on goldfish. From the video, we quantified several kinematic variables associated with the head and jaws of the feeding bass that were hypothesized to affect pressure. In a multiple regression, kinematic data accounted for 79.7% of the variation among strikes in minimum pressure. Faster mouth opening and hyoid depression were correlated with lower pressures, a...
TU-G-BRB-06: Improving the Dose Distribution and Delivery Efficiency in IMRT Inverse Planning by Iteratively Reweighted L1-Norm

Purpose: Compressed sensing with L1‐norm based total‐variation (TV) regularization has been successfully applied in IMRT inverse planning by generating piecewise constant fluence maps. L1‐norm was chosen primarily due to its computational efficiency; for sparse signal recovery, an ideal approach is to use L0‐norm (the number of non‐zero elements) or Lp‐norm (p<:1). It is, however, difficult to implement in practice as it is a non‐convex problem. The goal of this work is to introduce a substitute and yet effective method, which can further reduce the fluence‐map complexity and enhance delivery efficiency in IMRT inverse planning, while not damaging the conformal dose distribution. Methods: We propose to use an algorithm based on iteratively reweighted L1‐norm. The algorithm consists of solving a sequence of weighted L1‐norm minimization problems where the weights used for the next iteration are computed from the value of the current solution. In this work, a TV solver, called TFOCS, was used for each iteration. The proposed algorithm was evaluated on a prostate case for IMRT inverse planning. The treatment plans were evaluated by the conformation number (CN) and the modulation index (MI). Results: The iteratively reweighted L1‐norm outperforms the L1‐norm based TV method for fluence‐map optimization in both conformal dose distribution and delivery efficiency. Significantly, the proposed method by reweighting the TV form enables higher or similar conformal dose distribution with lower field complexity. At 60 segments, the complexity of the fluence‐map (MI) was reduced by 20%, while producing higher CN. This improvement will be more effective as the dose conformity gets stronger. Conclusions: The proposed method with the iteratively reweighted L1‐norm achieves more conformal dose distribution and improves the delivery efficiency by reducing the fluence‐map complexity compared with the conventional TV minimization for IMRT inverse planning.
Spatially programmable temperature control and measurement for chemically amplified photoresist processing

Preliminary performance data is presented for a new thermal processing module. The system is directed towards conducting the temperature sensitive baking and chilling steps for chemically amplified photoresists. The module is comprised of 49 individual heating zones. The zones can be controlled independently with separate temperature sensing, actuation and feedback control mechanisms. A supervisory control strategy is applied to coordinate the individual zones. An in-situ chill plate is used to enable a temperature controlled cool-down phase without the need for substrate movement. Results are presented to demonstrate temperature control over the plate to within plus or minus 0.02 degrees Celsius. Wafer temperature is controlled to within plus or minus 0.05 degrees Celsius as measured at 5 sites. Photomask processing results are presented depicting steady-state control to within plus or minus 0.05 degrees Celsius as measured at 16 sites within one quadrant of the substrate. The advantages of the system are discussed including better temperature uniformity than conventional systems and the ability to conduct multiple experiments in a single run by biasing the setpoint across the substrate.
Exact solutions to linear systems of equations using output sensitive lifting

Many methods have been developed to symbolically solve systems of linear equations over the rational numbers. A common approach is to use p-adic lifting or iterative refinement to build a modular or approximate solution, then apply rational number reconstruction. An upper bound can be computed on the number of iterations these algorithms must perform before applying rational reconstruction. In practice such bounds can be conservative. Output sensitive lifting is the technique of performing rational reconstruction at intermediate steps of the algorithm and verifying correctness which allows the possibility of early termination when the solution size is small. In this paper we show how using an appropriate output sensitive lifting strategy can improve several algorithms. We show this procedure to be computationally effective and introduce a variant of the iterative-refinement method that incorporates warm starts into the rational reconstruction procedure.
Therapeutic cryotherapy guided by MRI and ultrasound for haemangiomas in erector muscles of the back

SummaryThe indications, technique and results of cryotherapy for potentially hazardous paraspinal haemangiomas that would otherwise have to be treated surgically are described. Two men with back pain which limited work activity were treated by cryotherapy as an alternative to surgical therapy. Magnetic resonance imaging (MRI) was utilized for diagnosis and planning. Intrapro-cedural ultrasound was also utilized for guidance and monitoring. Techniques that were adapted from prostate cryotherapy with special probes are described. MRI proved crucial and essential for both diagnosis and planning. Laparoscopic ultrasound was also helpful. Both patients improved clinically and neither has required surgery with follow-up of over 1 year. No complications occurred. Image-guided cryotherapy, with at least 1 year follow-up, has been valuable to alleviate symptoms, avoid surgery, and permit patients to resume work.
Ligand-dependent regulation of T cell development and activation

Mature CD4+ and CD8 + T lymphocytes develop in the thymus from precursors with diverse clonally distributed receptors, possessing binding sites with negligible, intermediate, or high affinity for selfpeptide major histocompatibility complex (MHC) ligands. Positive- and negative-selection processes acting on this precursor pool yield a peripheral T cell population comprised of cells with receptors (TCR) capable of self-peptide MHC ligand recognition, but largely depleted of those able to mediate overt self-responsiveness. The Lymphocyte Biology Section of the Laboratory of Immunology studies how self-ligand recognition guides T cell development in the thymus and influences the functionality of naive and activated T cells in the periphery. It also seeks to define the molecular basis for the discrimination between self-ligands and foreign antigens that controls T cell activation to effector function. Finally, it uses a combination of conventional cellular immunological methods, biochemical and biophysical studies, and advanced imaging techniques to visualize, quantitate, and model the various steps in the development of primary and memory T cell immune responses.
How bacteria survive an acid trip

The evolutionary pressure to populate rewarding niches can require organisms to survive high-risk environments. For bacteria that inhabit the nutrient-rich human gut, whether they are our friends or foes, the trip through the stomach requires clever strategies to survive harsh, low-pH conditions. Gut-resident Escherichia coli strains deploy a complex set of responses to counter the impact of the low pH they experience as they travel through the stomach (1). Some of their responses, such as the amino acid decarboxylases, act to keep the cytoplasmic pH above a dangerous level. However, the permeability of the outer membrane leaves the periplasmic space unprotected from the perilously low pH of the external medium. Consequently, these bacteria had to develop strategies to protect periplasmic proteins from irreversible pH denaturation. A network of chaperones participates in this protection; the key pH-responsive members are the small, abundant HdeA and HdeB proteins, the activity of which is triggered by low pH. In a recent study reported in PNAS, Foit et al. (2) apply a multipronged approach to learn how E. coli HdeA uses low pH-induced protonation of a small number of acidic residues to shift from an inactive, stably folded dimeric state to a partially folded monomer that is capable of reversibly binding unfolded substrates.
Validation of Multiangle Imaging Spectroradiometer (MISR) aerosol optical thickness measurements using Aerosol Robotic Network (AERONET) observations over the contiguous United States

[1] Aerosol optical thickness (AOT) data retrieved by the Multiangle Imaging Spectroradiometer (MISR) in 2001 were compared with AOT measurements from 16 Aerosol Robotic Network (AERONET) sites over the contiguous United States. Overall, MISR and AERONET AOTs were strongly correlated (r = 0.73). Regression analysis showed that the root mean square error (RMSE) of MISR AOT was 0.05. The overall retrieval error of MISR AOT was within ±0.04 ± 0.18 × AOT. This result as well as the regression slope and intercept were comparable with previous results using AOT retrievals from MISR or Moderate Resolution Imaging Spectroradiometer (MODIS). The agreement between MISR and AERONET AOTs was improved (R2 = 0.90, RMSE = 0.04) when data from three western inland sites were excluded. A paired t test indicated that MISR systematically overestimated AOT by 0.02 ± 0.007. It was also shown that this positive bias in MISR AOT was greater during the spring and summer as well as in western United States. Together, these results suggest that MISR AOT measurements may be suitable for quantitative analysis of aerosol abundance. Finally, it is unlikely that the current results will vary when using alternative MISR AOT parameters since our analysis also showed the MISR AOT parameters (best fit, regional mean, and weighted regional mean AOTs) to be highly comparable.
Visually Similar Wavelets with Application to Data Hiding Systems

Transform domain information hiding has been an important field for several years. Recent parameterized methods have been introduced to expand the available key-space for information hiding techniques. This paper introduces and defines Visually Similar Wavelet systems. Visually Similar Wavelet systems are those pairs or sets of wavelets that preserve visually pleasing aspects of an image. The application of these techniques is discussed in the context of two different information hiding fields, watermarking and steganography. An example is presented illustrating the use in fragile watermarking.
Photon echo modulation effects in LaF3:Pr3+

Abstract Photon echo modulation effects have been observed in the 3 H 4 - 3 P 0 transition of LaF 3 :Pr 3+ in an applied magnetic field. Our results are interpreted as being due to the combined effect of the Pr nuclear Zeeman and hyperfine interaction.
Regulation of the S-Locus Receptor Kinase and Self-Incompatibility in Arabidopsis thaliana

Intraspecific mate selectivity often is enforced by self-incompatibility (SI), a barrier to self-pollination that inhibits productive pollen-pistil interactions. In the Brassicaceae, SI specificity is determined by two highly-polymorphic proteins: the stigmatic S-locus receptor kinase (SRK) and its pollen coat-localized ligand, the S-locus cysteine-rich protein (SCR). Arabidopsis thaliana is self fertile, but several of its accessions can be made to express SI, albeit to various degrees, by transformation with functional SRK-SCR gene pairs isolated from its close self-incompatible relative, Arabidopsis lyrata. Here, we use a newly identified induced mutation that suppresses the SI phenotype in stigmas of SRK-SCR transformants of the Col-0 accession to investigate the regulation of SI and the SRK transgene. This mutation disrupts NRPD1a, a gene that encodes a plant-specific nuclear RNA polymerase required for genomic methylation and production of some types of silencing RNAs. We show that NRPD1a, along with the RNA-dependent RNA polymerase RDR2, is required for SI in some A. thaliana accessions. We also show that Col-0 nrpd1a mutants exhibit decreased accumulation of SRK transcripts in stigmas, which is not, however, responsible for loss of SI in these plants. Together, our analysis of the nrpd1a mutation and of SRK promoter activity in various accessions reveals that the SRK transgene is subject to several levels of regulation, which vary substantially by tissue type and by accession. This study thus helps explain the well-documented differences in expression of SI exhibited by SRK-SCR transformants of different A. thaliana accessions.
Feedback reduction by thresholding in multi-user broadcast channels: Design and limits

To utilize the multi-user diversity in broadcast channels, the channel state information (CSI) of each user must be known at the transmitter. To reduce the overhead of CSI feedback under random beamforming the question of which receivers should feed back their CSI is investigated. Using the closed form expression for the SINR distribution, thresholding functions T(n) are designed to meet specific design criterion as a function of the number of receivers. Specifically three design criterion are proposed. The asymptotic limits of the successful thresholding functions T(n) are found. If T(n) scales slower than log n, asymptotically no performance is lost. If T(n) scales faster than log n, all multi-user diversity is lost.
Characterization of a diffusion-bonded Al-Mg alloy/SiC interface by high resolution and analytical electron microscopy

The interfacial structure of a diffusion-bonded Al-4.55 at. pct Mg/SiC interface was examined by conventional and high-resolution transmission electron microscopy. Formation of Mg2Si, MgO, and Al2MgO4 was observed. The monoclinic Mg2Si phase formed at the Al/SiC interface, while the oxides MgO and Al2MgO4 formed at the monoclinic Mg2Si/Al interface. It is shown that the formation of these phases can be predicted using simple thermodynamic criteria such as the relative bond strengths between Al, Si, C, O, and Mg. In addition, precipitation of some equilibrium Al8Mg5 precipitate was also observed at the interface. The interfacial structure observed in the Al-Mg/SiC system is contrasted with that observed in the pure Al/SiC system.
Oncoproteomic profiling with antibody microarrays

The incidence of cancer and its associated mortality are increasing globally, indicating an urgent need to develop even more effective and sensitive sets of biomarkers that could help in early diagnosis and consequent intervention. Given that many cellular processes are carried out by proteins, cancer research has recently shifted toward an exploration of the full proteome for such discovery. Among the advanced methodologies that are being developed for analyzing the proteome, antibody microarrays have become a prominent tool for gathering the information required for a better understanding of disease biology, early detection, discrimination of tumors and monitoring of disease progression. Here, we review the technical aspects and challenges in the development and use of antibody microarray assays and examine recently reported applications in oncoproteomics.
Should coronary artery bypass be delayed following successful direct coronary artery streptokinase thrombolysis during evolving myocardial infarction

Abstract The effect of deferring immediate coronary artery bypass was evaluated in two groups of similar patients having successful direct coronary artery thrombolysis with streptokinase in the treatment of evolving myocardial infarction. Within 6 hours of onset of myocardial infarction, 140 patients underwent immediate cardiac catheterization and infusion of intracoronary streptokinase up to 500,000 units. Of those patients having restoration of orthograde coronary blood flow coupled with immediate evidence of myocardial salvage, 31 patients (group I) had immediate coronary artery bypass and 34 patients (group II) had coronary artery bypass deferred. Group I had no hemorrhagic, hemodynamic, or new cardiac complications. There were no deaths, reinfarction, recurrence of angina, or loss of salvaged myocardium at restudy. In group II, 11 of 34 patients had early reinfarction (p
Conformational differences between the Pfr and Pr states in Pseudomonas aeruginosa bacteriophytochrome

Phytochromes are red-light photoreceptors that regulate light responses in plants, fungi, and bacteria by means of reversible photoconversion between red (Pr) and far-red (Pfr) light-absorbing states. Here, we report the crystal structure of the Q188L mutant of Pseudomonas aeruginosa bacteriophytochrome (PaBphP) photosensory core module, which exhibits altered photoconversion behavior and different crystal packing from wild type. We observe two distinct chromophore conformations in the Q188L crystal structure that we identify with the Pfr and Pr states. The Pr/Pfr compositions, varying from crystal to crystal, seem to correlate with light conditions under which the Q188L crystals are cryoprotected. We also compare all known Pr and Pfr structures. Using site-directed mutagenesis, we identify residues that are involved in stabilizing the 15Ea (Pfr) and 15Za (Pr) configurations of the biliverdin chromophore. Specifically, Ser-261 appears to be essential to form a stable Pr state in PaBphP, possibly by means of its interaction with the propionate group of ring C. We propose a "flip-and-rotate" model that summarizes the major conformational differences between the Pr and Pfr states of the chromophore and its binding pocket.
Secreted effector proteins of Salmonella enterica serotype typhimurium elicit host-specific chemokine profiles in animal models of typhoid fever and enterocolitis

Salmonella enterica serotype Typhimurium causes enterocolitis in humans, a localized infection characterized by diarrhea and by pathological changes that are most severe in the intestine and mesenteric lymph nodes (24, 25). In contrast, S. enterica serotype Typhi causes typhoid fever, a systemic infection characterized by fever, while diarrhea is considered to be an insignificant symptom developing in only one-third of patients (28). A striking difference between the host responses elicited during infections with serotype Typhimurium and serotype Typhi in humans is the type of inflammation observed in the intestine. Analysis of biopsy samples reveals that inflammation in the intestines of patients infected with serotype Typhimurium is characterized by an infiltrate that is composed primarily of polymorphonuclear (PMN) cells (6, 27), while inflammation in typhoid fever patients is caused predominantly by infiltration with monocytes (21, 39). Similarly, the predominant cell type (representing 95% of fecal leucocytes) in stools from typhoid fever patients is mononuclear, whereas PMN cells predominate (representing 75% of fecal leucocytes) in stool samples from enterocolitis patients (13).
Insect Pests of Upholstered Furniture

Insects as pests of upholstered furniture have become much more destructive during the past few years. This seems to be the result of the increased sales of upholstered furniture covered with woolen fabrics and filled with vegetable or animal materials susceptible to insect attack. Psocids and the tobacco beetle, while annoying to the owner, seldom appear to affect seriously the appearance or usefulness of furniture. Carpet beetles are minor pests, except in the case of the furniture carpet beetle. This insect is capable of rendering furniture both unsightly and unusable by devouring hair and feather upholsterings and by feeding on the wool in covers. Clothes moths; more especially the webbing clothes moth, are the most destructive of all pests since they persistently attack woolen covers, are so widely distributed, and spread so easily.
Tungsten hexacarbonyl and hydrogen peroxide as precursors for the growth of tungsten oxide thin films on titania nanoparticles

W(CO)6 and H2O2 were used in an atomic layer deposition (ALD)-like process to grow thin WOx films onto TiO2 powders in a fluidized bed reactor. Carbonyl precursors are not widely used in this application, so that deviations from an ideal ALD process, previously not examined with W(CO)6, were identified. The resulting WOx films were a result of both ALD-like and chemical vapor deposition-based growth modes. A chemical reaction mechanism incorporating a combination of these two growth modes was inferred. As the move to expand the range of ALD precursors meets with the desire to scale up these processes, the simultaneous appearance of both these growth modes is likely to become more and more common, and so understanding the interaction of these two types of surface reactions is key to progress in the field. The films were observed to inhibit the anatase-to-rutile phase transformation in the TiO2 powders upon high temperature annealing, while crystallization of the amorphous WO3 was also not observed. Changes in the local bonding within the WO3 were observed and associated with changes in the structural nature of the film and its interface to the substrate. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1278–1286, 2014
Towards Accountable Enterprise Mashup Services

As a result of the proliferation of Web 2.0 style Web sites, the practice of mashup services has become increasingly popular in the Web development community. While mashup services bring flexibility and speed in delivering new valuable services to consumers, the issue of accountability associated with the mashup practice remains largely ignored by the industry. Furthermore, realizing the great benefits of mashup services, industry leaders are eagerly pushing these services into the enterprise arena. Although enterprise mashup services hold great promise in delivering a flexible SOA solution in a business context, the lack of accountability in current mashup solutions may render this ineffective in the enterprise environment. This paper defines accountability for mashup services, analyses the underlying issues in practice, and finally proposes a framework and ontology to model accountability. This model may then be used to develop effective accountability solutions for mashup environments.
A SNAPSHOT OF TECHNOLOGY INTEGRATION TRAINING IN TEACHER EDUCATION PROGRAMS

Background and purpose . There is not a consensus on how teacher candi- dates in teacher training programs are prepared to teach with technology. While the National Association of State Boards of Education (2012) held that the training of teachers “too often has not kept pace with advances in technology or new ways of learning” and that educators were not being prepared to use technology effectively in classroom, the American Association of Colleges for Teacher Education (2013) indi- cated that almost all of the teacher candidates are well prepared to integrate techno- logy into their instruction. Aim and method. This study took a snapshot of 83 teacher training programs in two states: Illinois and Nebraska to identify how their teacher training programs prepared their candidates to teach with technology.
Active Control of Passive Dynamics for Ground Disturbance Rejection

approved: Dr. Jonathan Hurst We present a model for running that combines active control with passive dynamics, in an attempt to approach the economy and robustness of animal running. Our work is inspired by examples of guinea fowl encountering an unexpected drop in ground surface, with little affect on their running gait. Previous investigations have shown that the steady-state center-of-mass motion of animal running and walking may be approximated by a mass bouncing upon a spring, but this approximation does not incorporate disturbance rejection. To approach the robustness of animal running, we add a motor in series with our spring, and use it for closed-loop force control. The active controller maintains the force profile of the vertically hopping spring-mass model in the presence of disturbances, while the series spring does the majority of the mechnical work, maintaining the economy of the purely passive spring-mass system. We show in simulation that our force-controlled model is more resilient to ground disturbances that affect the center-of-mass trajectory, toe-force profile and hopping frequency than the uncontrolled model.