cssi/SciSciGPT-SciSciNet huggingface dataset:
Excited-State Geometry Method for Calculation of the Absolute Resonance Raman Cross Sections of the Aromatic Amino Acids

The time correlator formalism was used to calculate the absolute resonance Raman cross sections for the aromatic amino acids based on density functional theory calculations of the ground-state potential energy surfaces combined with projection along normal mode eigenvectors in the excited state. The geometric difference between the minima of the ground and excited states along each normal mode was calculated to provide inputs for the time correlator in the linear approximation. The calculated dimensionless nuclear displacements, Delta(i), provide the electron-phonon coupling constants, S(i) = Delta(i)(2)/2, for the corresponding Raman active mode of frequency omega(t). The method is generally applicable to molecules that are Franck-Condon active. As an example we have chosen to calculate the absolute resonance Raman cross sections of models of the aromatic amino acids phenylalanine, tyrosine, and tryptophan. We discuss the role played by substituents on the aromatic ring that decrease vibronic activity to a level that permits application of the time correlator. While the method may have limitations for molecules of high symmetry, the current study of excited-state displacements and electronic structure indicates that the L(a),(b) states are Franck-Condon active in the aromatic molecules studied.
SU‐E‐CAMPUS‐J‐02: Exploring Appropriate CT Acquisition Parameters for Measuring Tumor Volumes in Response Assessment Using An Anthropomorphic Thorax Phantom

Purpose: Early tumor volume change holds promise for detecting the biologic activity of systemic therapy in non‐small cell lung cancer. It is imperative to optimize and standardize CT imaging protocols to further investigate volumetric response. This study explored the effects of CT acquisition parameters on volume measurements using a thorax phantom and segmentation algorithm. Methods: Eight phantom nodules of known volume (small size of 520–540mm^3, nominal diameter of 1mm and large size of 4210–4320mm^3, nominal diameter of 2mm), shape (spherical, elliptical) and density (−10 and +100 HU) were scanned on a GE VCT at four doses (25, 50, 100, and 200 mAs). For each scan, six image series were reconstructed at three slice intervals of 5, 2.5 and 1.25mm, and using the lung and standard reconstruction algorithms. Each nodule's volume was measured using an in‐house segmentation algorithm. Relative difference in volume (RDiV = (Algorithm‐True)/True*100%) was calculated. Linear mixed effects models were fitted to examine the effect of dose, and the combinations of slice thickness and reconstruction algorithm. Results: Dose did not affect the RDiV after adjusting for slice thickness and reconstruction algorithm (p=0.40). The combination of 1.25mm/standard had an estimated RDiv of −0.001 which was closest to 0. Slice thickness of 1.25mm/lung and 2.5mm/standard were not statistically different from 1.25mm/standard. Estimated differences of −6.3%(p=0.002), 7.1% (p<0.001), and 7.3%(p<0.001) in RDiV were observed for 2.5mm/lung, 5mm/standard and 5mm/lung when compared to 1.25mm/standard, respectively. Conclusion: Imaging acquisition parameters of CT slice thickness and reconstruction algorithm affect the accuracy and precision of lung nodule volume measurements to various degrees while dose has almost no effect. Our findings may help determine appropriate CT imaging acquisition parameters for clinical trials and care. Validation studies using different segmentation algorithms are warranted. This work is in part supported by Dr. Binsheng Zhao's NIH R01 CA149490. No other conflict of interest.
TrkB kinase activity is critical for recovery of respiratory function after cervical spinal cord hemisection

Neuroplasticity following spinal cord injury contributes to spontaneous recovery over time. Recent studies highlight the important role of brain-derived neurotrophic factor (BDNF) signaling via the high-affinity tropomyosin-related kinase (Trk) receptor subtype B (TrkB) in recovery of rhythmic diaphragm activity following unilateral spinal hemisection at C2 (C2SH). We hypothesized that TrkB kinase activity is necessary for spontaneous recovery of diaphragm activity post-C2SH. A chemical-genetic approach employing adult male TrkB(F616A) mice (n=49) was used to determine the impact of inhibiting TrkB kinase activity by the phosphoprotein phosphatase 1 inhibitor derivative 1NMPP1 on recovery of ipsilateral hemidiaphragm EMG activity. In mice, C2SH was localized primarily to white matter tracts comprising the lateral funiculus. The extent of damaged spinal cord (~27%) was similar regardless of the presence of functional recovery, consistent with spontaneous recovery reflecting neuroplasticity primarily of contralateral spared descending pathways to the phrenic motor pools. Ipsilateral hemidiaphragm EMG activity was verified as absent in all mice at 3days post-C2SH. By 2weeks after C2SH, ipsilateral hemidiaphragm EMG activity was present in 39% of vehicle-treated mice compared to 7% of 1NMPP1-treated mice (P=0.03). These data support the hypothesis that BDNF/TrkB signaling involving TrkB kinase activity plays a critical role in spontaneous recovery of diaphragm activity following cervical spinal cord injury.
Anisotropy of the Upper Critical Field in (TMTSF)2PF6

The temperature dependence of the upper critical magnetic field ${H}_{c2}(T)$ in the quasi-one-dimensional molecular superconductor (TMTSF${)}_{2}$P${\mathrm{F}}_{6}$ was determined via resistivity, for the intrachain (a), interchain (b), and interplane $({\mathbf{c}}^{*})$ directions. For H along a and b, ${H}_{c2}(T)$ exhibits pronounced positive curvature, with no sign of saturation to 0.1 K. A novel anisotropy inversion is observed, wherein ${H}_{c2}^{b}$ grows larger than ${H}_{c2}^{a}$ and exceeds the paramagnetic limit by more than 200%. The anomalous shape of ${H}_{c2}(T)$ is consistent with recent predictions of unconventional behavior in anisotropic superconductors, including the possibility of triplet pairing and reentrant superconductivity in very high field.
Hypercalcemia Associated with Calcium Supplement Use: Prevalence and Characteristics in Hospitalized Patients.

Background: The ingestion of large amounts of milk and antacids to treat peptic ulcer disease was a common cause of hypercalcemia in the past (the “milk-alkali syndrome”). The current popularity of calcium and supplements has given rise to a similar problem. Objectives: To evaluate the prevalence and characteristics of hypercalcemia induced by calcium intake (“calcium supplement syndrome”; or CSS) in hospitalized patients. Methods: We conducted a retrospective; electronic health record (EHR)-based review of patients with hypercalcemia over a 3-year period. Diagnosis of CSS was based on the presence of hypercalcemia; a normal parathyroid hormone (PTH) level; renal insufficiency; metabolic alkalosis; a history of calcium intake; and documented improvement with treatment. Results: Of the 72 patients with non-PTH mediated hypercalcemia; 15 (20.8%) satisfied all the criteria for the diagnosis of CSS. Calcium; vitamin D; and multivitamin ingestion were significantly associated with the diagnosis (p values < 0.0001; 0.014; and 0.045 respectively); while the presence of hypertension; diabetes; and renal insufficiency showed a trend towards statistical significance. All patients received intravenous fluids; and six (40%) received calcium-lowering drugs. The calcium level at discharge was normal 12 (80%) of patients. The mean serum creatinine and bicarbonate levels decreased from 2.4 and 35 mg/dL on admission respectively; to 1.6 mg/dL and 25.6 mg/dL at discharge respectively. Conclusion: The widespread use of calcium and vitamin D supplementation can manifest as hypercalcemia and worsening of kidney function in susceptible individuals. Awareness among health care professionals can lead to proper patient education regarding these health risks.
Educating electrical engineers for professional careers

In any current discussion of engineering education, particularly electrical engineering education, inevitably a conflict arises between those who wish to inject more science and mathematics into curricula and others who insist that engineering colleges should train engineers, not scientists. This paper supports neither side of this controversy but presents the arguments for the following thesis: The present emphasis on science and mathematics in electrical engineering curricula is creating a research-oriented type of undergraduate education that may lead to inadequate preparation for professional careers. Since 80 to 90% of the undergraduates intend to follow professional rather than research or teaching careers, re-evaluation of the goals of undergraduate education is required.
Inherently safer analysis of the attainable region process for the adiabatic oxidation of sulfur dioxide

Abstract The attainable region (AR) method is used to obtain the optimal design and operating conditions for the adiabatic oxidation of sulfur dioxide to sulfur trioxide. The optimum process layout for this exothermic, catalytic, reversible reaction is a complex interconnection of reactors that achieves a conversion in excess of the equilibrium value for a single adiabatic reactor. The complex design obtained from the AR method is technically and economically superior to a single adiabatic reactor but it is inferior from a safety perspective as a result of its complex interconnections and its high preheat temperature. The strategies of inherently safer design (minimize, substitute, moderate, and simplify) have been applied to the complex design to compare it with conventional adiabatic reactor designs.
Large body size in the pygmy swordtail Xiphophorus pygmaeus

Fishes in the genus Xiphophorus (swordtails and platyfishes) are well known for the influence of the pituitary (P) locus on variation of male size at maturity both within and among species. We report the discovery of large male size ( >29 mm SL) in several populations of the swordtail X. pygmaeus, a species previously thought to consist of only small males (<29 mm SL). Large size is geographically restricted, and average male size varies significantly by site and year sampled in a pattern suggesting a recent origin and slow spreading of the large male phenotype. However, large male size is not strongly patternally inherited in this species, as it is in its two closest relatives, X. nigrensis and X. multilineatus, showing that large size does not result from the same genetic (P locus) mechanism. Large X. pygmaeus males do not court, can exhibit the gold morph, do not possess swords and have slender body shape. In these traits they resemble small conspecific males and small males of X. nigrensis and X. multilineatus rather than large males of these latter two species. This shows that correlations between morphological and behavioural traits that occur in X. nigrensis and X. multilineatus are absent in X. pygmaeus.
Analysis and numerical simulation of phytoplankton-nutrient systems with nutrient loss

The dynamics of a mathematical model of a layer of single phytoplankton species growing over a pool of nutrients, proposed by [A.H. Taylor, J.R.W. Harris, J. Aiken, The interaction of physical and biological process in a model of the vertical distribution of phytoplankton under stratification, Mar. Int. Ecohyrd., J.C. Nihoul (Ed.) 42 (1986) 313-330] is analyzed. Both cases of presence and absence of a phytoplankton in the water below the layer of interest are considered. Positive and elementary stable nonstandard (PESN) methods, having the same qualitative features as the corresponding continuous models, are formulated and analyzed. Biological implications and a set of numerical simulations supporting the mathematical and numerical analysis are also presented.
The first nobel prize for integrated systems physiology: Ivan Petrovich Pavlov, 1904.

The centennial of the awarding of the Nobel Prize in Physiology or Medicine to Russian Academician Ivan P. Pavlov (FIGURE 1[⇓][1]) is an occasion for assessing the paths opened to modern integrated systems physiology and medicine by discoveries at Pavlov’s city laboratory in St. Petersburg and
Accuracy of providers' assessment of pain during intrauterine device insertion

Abstract Background Providers often underestimate patient pain. This study investigated if providers accurately assess pain during intrauterine device (IUD) insertion. Study Design This is a secondary analysis of a randomized trial. Participants rated pain on a 100-mm visual analogue scale (VAS). Providers marked a similar VAS for maximum level and timing of participant pain. Results The mean patient maximum pain was 64.8 mm (SD, 27) compared to 35.3 mm (SD, 26) rated by the provider (p Conclusions Providers underestimate pain during IUD insertion. Implications To our knowledge, this is the first paper to compare provider and patient perceptions of pain during IUD insertion. Understanding this relationship will help guide further research about IUD insertion pain and techniques and could improve patient counseling.
Adenyl cyclase from renal cortex

Abstract Studies were carried out to characterize the parathyroid hormone-sensitive adenyl cyclase from rat renal cortex. The enzyme activity was tightly associated with the particulate fraction, and was not effectively solubilized by treatment with a variety of surface-active agents. The enzyme showed considerable contamination by ATPase, which was not separated from adenyl cyclase by gel filtration, although cyclic 3′,5′-nucleotide phosphodiesterase was removed by this procedure. Filtering the enzyme through a shallow bed of agarose gel gave a preparation with increased specific activity and a linear relationship between activity and concentration of enzyme protein. Adenyl cyclase activity was detected over the pH range 6.0 to 9.0, with optimal parathyroid hormone- and fluoride-stimulated activity at pH 8.0 and 7.5, respectively. Fluoride-stimulated activity was maximal at 8 mM F − . Incubation of the enzyme at 37° caused progressive loss in activity. A sex difference was observed in the response of the enzyme to monovalent cations. Enzyme from female rats showed inhibition of basal activity by 50 mM Li + , and no effect of Na + , K + , or Rb + , whereas enzyme from males showed significant activation of basal and hormone-stimulated reactions by 50 mM K + and Rb + . The enzyme required either Mn 2+ or Mg 2+ and the latter afforded optimal activation by parathyroid hormone and F − . The optimal concentration of Mg 2+ varied with the concentration of substrate used. At higher concentrations of ATP (5, 10, 20 mM), optimal Mg 2+ /ATP ratios approximated 1.0. At lower levels of ATP (0.5, 1.0 mM) optimum Mg 2+ /ATP ratios ranged from 0.5 to 3.0. In the presence of optimal Mg 2+ , Ca 2+ inhibited adenyl cyclase, with 50% inhibition at approximately 2 mM Ca 2+ . Mn 2+ also inhibited the enzyme, but was less effective than Ca 2+ , giving 50% inhibition of hormone and F − reactions at 5 and 7.5 mM, respectively. The apparent affinity of the enzyme for ATP was much lower than has been found with the enzyme from other tissue. Even at concentrations of ATP as high as 20 mM, there was no evidence for saturation of the enzyme with substrate. Parathyroid hormone or F − affected the enzyme through an increase in v max without a detectable change in affinity for ATP.
Ferrocene/ferrocenium ion as a catalyst for the photodecomposition of chloroform

Irradiation (λ > 320 nm) of ferrocene in chloroform causes decomposition of chloroform and the accumulation of HCl, CCl3OOH, and C2Cl6. This appears to occur initially through a cycle in which (a) ferrocene is oxidized to ferrocenium and tetrachloroferrate ions, (b) FeCl4− undergoes photodissociation, and (c) ferrocenium reoxidizes the chloroferrate(II) species. On extended photolysis, the concentrations of CCl3OOH and FeCl4− build up and a competing cycle in which FeCl4− is restored through oxidation of the chloroferrate(II) species by CCl3OOH accelerates the decomposition rate.
Development and distribution of neuronal cilia in mouse neocortex

Neuronal primary cilia are not generally recognized, but they are considered to extend from most, if not all, neurons in the neocortex. However, when and how cilia develop in neurons are not known. This study used immunohistochemistry for adenylyl cyclase III (ACIII), a marker of primary cilia, and electron microscopic analysis to describe the development and maturation of cilia in mouse neocortical neurons. Our results indicate that ciliogenesis is initiated in late fetal stages after neuroblast migration, when the mother centriole docks with the plasma membrane, becomes a basal body, and grows a cilia bud that we call a procilium. This procilium consists of a membranous protrusion extending from the basal body but lacking axonemal structure and remains undifferentiated until development of the axoneme and cilia elongation starts at about postnatal day 4. Neuronal cilia elongation and final cilia length depend on layer position, and the process extends for a long time, lasting 8-12 weeks. We show that, in addition to pyramidal neurons, inhibitory interneurons also grow cilia of comparable length, suggesting that cilia are indeed present in all neocortical neuron subtypes. Furthermore, the study of mice with defective ciliogenesis suggested that failed elongation of cilia is not essential for proper neuronal migration and laminar organization or establishment of neuronal polarity. Thus, the function of this organelle in neocortical neurons remains elusive.
A comparison of molecular-based models to determine vapor–liquid phase coexistence in hydrogen fluoride

Abstract In this work, we apply the Gibbs–Duhem integration (GDI) technique to obtain the vapor–liquid equilibrium (VLE) properties of hydrogen fluoride according to three potential models. Properties examined include coexistence densities, enthalpy of vaporization, and vapor pressure. The models are representative of the various types of potentials used in simulation studies; namely, a pure pair potential from ab initio studies, an effective pair potential which fits parameters to condensed phase properties, and a semi-empirical pair potential. The effective pair potential was found to be the best performer of the three potentials tested, with semi-quantitative agreement with experiment. The other potentials which, by definition, did not include 3+ body effects performed poorly at most states. The effective pair potential is used to specify parameters in a Statistical Associating Fluid Theory (SAFT) model for hydrogen fluoride (HF). Significant improvement is seen over previous attempts to model HF using SAFT, although shortcomings do remain.
Effect of CD44 binding peptide conjugated to an engineered inert matrix on maintenance of breast cancer stem cells and tumorsphere formation.

Introduction As cancer cells are affected by many factors in their microenvironment, a major challenge is to isolate the effect of a specific factor on cancer stem cells (CSCs) while keeping other factors unchanged. We have developed a synthetic inert 3D polyethylene glycol diacrylate (PEGDA) gel culture system as a unique tool to study the effect of microenvironmental factors on CSCs response. We have reported that CSCs formed in the inert PEGDA gel by encapsulation of breast cancer cells maintain their stemness within a certain range of gel stiffness. The objective was to investigate the effect of CD44 binding peptide (CD44BP) conjugated to the gel on the maintenance of breast CSCs.
Positively charged templates for labeling internalizing antibodies: comparison of N-succinimidyl 5-iodo-3-pyridinecarboxylate and the D-amino acid peptide KRYRR.

Receptor-mediated internalization of monoclonal antibodies (mAbs), such as those specific for the epidermal growth factor receptor variant III (EGFRvIII), can lead to rapid loss of radioactivity from the target cell. In the current study, the anti-EGFRvIII mAb L8A4 was radioiodinated using two methods -N-succinimidyl 5-iodo-3-pyridinecarboxylate (SIPC) and via a D-amino acid peptide LysArgTyrArgArg (D-KRYRR). Paired-label internalization assays performed on EGFRvIII-expressing U87ΔEGFR cells in vitro demonstrated that labeling L8A4 using D-KRYRR resulted in significantly higher retention of radioiodine in the intracellular compartment. In athymic mice with D256 human glioma xenografts, tumor uptake was similar for both labeling methods through 24 hr. However, an up to fourfold higher tumor retention was observed for mAb labeled with the D-amino acid peptide at later time points. Radiation absorbed dose calculations based on these biodistribution data indicated that L8A4 labeled using D-KRYRR exhibited better tumor-to-normal-organ radiation dose ratios, suggesting that this labeling method may be of particular value for labeling internalizing mAbs.
Shock-Wave/Boundary-Layer Interactions in Hypersonic Low Density Flows

Results of numerical simulations of Mach 10 air flow over a hollow cylinder-flare and a double-cone are presented where viscous effects are significant. The flow phenomena include shock-shock and shock- boundary-layer interactions with accompanying flow separation, recirculation, and reattachment. The purpose of this study is to promote an understanding of the fundamental gas dynamics resulting from such complex interactions and to clarify the requirements for meaningful simulations of such flows when using the direct simulation Monte Carlo (DSMC) method. Particular emphasis is placed on the sensitivity of computed results to grid resolution. Comparisons of the DSMC results for the hollow cylinder-flare (30 deg.) configuration are made with the results of experimental measurements conducted in the ONERA RSCh wind tunnel for heating, pressure, and the extent of separation. Agreement between computations and measurements for various quantities is good except that for pressure. For the same flow conditions, the double- cone geometry (25 deg.- 65 deg.) produces much stronger interactions, and these interactions are investigated numerically using both DSMC and Navier-Stokes codes. For the double-cone computations, a two orders of magnitude variation in free-stream density (with Reynolds numbers from 247 to 24,7 19) is investigated using both computational methods. For this range of flow conditions, the computational results are in qualitative agreement for the extent of separation with the DSMC method always predicting a smaller separation region. Results from the Navier-Stokes calculations suggest that the flow for the highest density double-cone case may be unsteady; however, the DSMC solution does not show evidence of unsteadiness.
Nitric Oxide-induced Deamination of Cytosine and Guanine in Deoxynucleosides and Oligonucleotides

The autoxidation of nitric oxide (NO.) forms the nitrosating agent N2O3, which can directly damage DNA by deamination of DNA bases following nitrosation of their primary amine functionalities. Within the G:C base pair, deamination results in the formation of xanthine and uracil, respectively. To determine the effect of DNA structure on the deamination of guanine and cytosine, the NO.-induced deamination rate constants for deoxynucleosides, single- and double-stranded oligonucleotides, and a G-quartet oligonucleotide were measured. Deamination rate constants were determined relative to morpholine using a Silastic membrane to deliver NO. at a rate of approximately 10-20 nmol/ml/min for 60 min, yielding a final concentration of approximately 600-1200 microM NO2-. GC/MS analysis revealed formation of nanomolar levels of deamination products from millimolar concentrations of deoxynucleosides and oligomers. Deamination rate constants for cytosine and guanine in all types of DNA were lower than the morpholine nitrosation rate constant by a factor of approximately 10(3)-10(4). Xanthine was formed at twice the rate of uracil, and this may have important consequences for mechanisms of NO.-induced mutations. Single-stranded oligomers were 5 times more reactive than deoxynucleosides toward N2O3. Double-stranded oligomers were 10-fold less reactive than single-stranded oligomers, suggesting that Watson-Crick base pairing protects DNA from deamination. G-quartet structures were also protective, presumably because of hydrogen bonding. These results demonstrate that DNA structure is an important factor in determining the reactivity of DNA bases with NO.-derived species.
Data MULEs: modeling and analysis of a three-tier architecture for sparse sensor networks

Abstract This paper presents and analyzes a three-tier architecture for collecting sensor data in sparse sensor networks. Our approach exploits the presence of mobile entities (called MULEs) present in the environment. When in close range, MULEs pick up data from the sensors, buffer it, and deliver it to wired access points. This can lead to substantial power savings at the sensors as they only have to transmit over a short-range. This paper focuses on a simple analytical model for understanding performance as system parameters are scaled. Our model assumes a two-dimensional random walk for mobility and incorporates key system variables such as number of MULEs, sensors and access points. The performance metrics observed are the data success rate (the fraction of generated data that reaches the access points), latency and the required buffer capacities on the sensors and the MULEs. The modeling and simulation results can be used for further analysis and provide certain guidelines for deployment of such systems.
On the distributions of the relative phase of complex wavelet coefficients

In this paper, the probability distributions of relative phase are studied. We proposed von Mises and wrapped Cauchy for the probability density function (pdf) of the relative phase in complex wavelet domain. The maximum-likelihood method is used to estimate the two parameters of von Mises and wrapped Cauchy. We demonstrate that the von Mises and wrapped Cauchy fit well with real data obtained from various real images including texture images as well as natural images. The von Mises and wrapped Cauchy models are compared, and the simulation results show that the wrapped Cauchy fits well with the peaky and heavy-tailed pdf of the relative phase and the von Mises fits well with the pdf which is in Gaussian shape. For most of the test images, the wrapped Cauchy model is more accurate than the von Mises, when images are decomposed by different complex wavelet transforms including dual-tree complex wavelet (DTCWT), pyramidal dual-tree directional filter bank (PDTDFB) and a modified version of curvelet.
Privacy oracle: a system for finding application leaks with black box differential testing

We describe the design and implementation of Privacy Oracle, a system that reports on application leaks of user information via the network traffic that they send. Privacy Oracle treats each application as a black box, without access to either its internal structure or communication protocols. This means that it can be used over a broad range of applications and information leaks (i.e., not only Web traffic or credit card numbers). To accomplish this, we develop a differential testing technique in which perturbations in the application inputs are mapped to perturbations in the application outputs to discover likely leaks; we leverage alignment algorithms from computational biology to find high quality mappings between different byte-sequences efficiently. Privacy Oracle includes this technique and a virtual machine-based testing system. To evaluate it, we tested 26 popular applications, including system and file utilities, media players, and IM clients. We found that Privacy Oracle discovered many small and previously undisclosed information leaks. In several cases, these are leaks of directly identifying information that are regularly sent in the clear (without end-to-end encryption) and which could make users vulnerable to tracking by third parties or providers.
A Unique 520–590 GHz Biased Subharmonically-Pumped Schottky Mixer

We report on the design and performance of a novel broadband, biased, subharmonic 520-590 GHz fix-tuned frequency mixer that utilizes planar Schottky diodes. The suspended stripline circuit is fabricated on a GaAs membrane mounted in a split waveguide block. The chip is supported by thick beam leads that are also used to provide precise radio frequency (RF) grounding, RF coupling and dc/intermediate frequency connections. At room temperature, the mixer has a measured double sideband noise temperature of 3000 to 4000 K across the design band.
Weighted averaging of evoked potentials

Weighted averages of brain evoked potentials (EPs) are obtained by weighting each single EP sweep prior to averaging. These weights are shown to maximize the signal-to-noise ratio (SNR) of the resulting average if they satisfy a generalized eigenvalue problem involving the correlation matrices of the underlying signal and noise components. The signal and noise correlation matrices are difficult to estimate and the solution of the generalized eigenvalue problem is often computationally impractical for real-time processing. Correspondingly, a number of simplifying assumptions about the signal and noise correlation matrices are made which allow an efficient method of approximating the maximum SNR weights. Experimental results are given using actual auditory EP data which demonstrate that the resulting weighted average has estimated SNRs that are up to 21% greater than the conventional ensemble average SNR. >
The Effects of Sulfur, Thiol, and Thiol Inhibitor Compounds on Arsine-Induced Toxicity in the Human Erythrocyte Membrane

The mechanism of arsine (AsH3) toxicity is not completely understood. The first cytotoxic effect of AsH3 is disruption of ion homeostasis, with a subsequent hemolytic action. The only accepted treatment for AsH3 toxicity is exchange transfusion of the blood. In this study the effect of sulfur, sulfur compounds, thiolcontaining compounds, and thiol inhibitors on AsH3-induced disruption of membrane transport and hemolysis in human erythrocytes was investigated in vitro. Elemental sulfur, sodium thiosulfate, 5,5*-dithio-bis(2-nitrobenzoic acid), and meso-2,3dimercaptosuccinic acid were successful in delaying hemolysis, but the most successful agent was the sulfhydryl inhibitor, N-ethylmaleimide (NEM). This indicated that sulfhydryl groups, possibly membrane sulfhydryls, are major factors in the hemolytic mechanism of AsH3. Measuring intracellular ion concentrations tested the effect of NEM on AsH3-induced disruption of membrane transport. AsH3 alone caused all ions tested to flow with their concentration gradients: Intracellular K 1 and Mg 11 decreased,
Competition in variable environments: experiments with planktonic rotifers

SUMMARY 1. In a constant environment, competition often tends to reduce species diversity. However, several theories predict that temporal variation in the environment can slow competitive exclusion and allow competing species to coexist. This study reports on laboratory competition experiments in which two pairs of planktonic rotifer species competed for a phytoplankton resource under different conditions of temporal variability in resource supply. 2. For both species pairs, Keratella cochlearis dominated under all conditions of temporal variability, and the other species (Brachionus calyciflorus or Synchaeta sp.) almost always went extinct. Increasing temporal variation in resource supply slowed competitive exclusion but did not change competitive outcome or allow coexistence. 3. Rotifers show a gleaner–opportunist trade-off, because gleaner species have low threshold resource levels (R*) and low maximum population growth rates, while opportunist species have the opposite characteristics. In the competition experiments, the gleaner always won and the opportunists always lost. Thus, a gleaner–opportunist tradeoff was not sufficient to facilitate coexistence under conditions of resource variability. Instead, the winning species had both the lowest R* and the greatest ability to store resources and ration their use during times of extreme resource scarcity.
Building Data Centers With Optically Connected Memory

Future data centers will require novel, scalable memory architectures capable of sustaining high bandwidths while still achieving low memory access latencies. Electronic interconnects cannot meet the challenges presented by the need for multi-terabit off-chip memory data paths. In this work, the electronic bus between main memory and its host processor is replaced with a circuit-switched optical interconnection network. We investigate the impact of our optically connected memory system on large-scale architectures and experimentally validate the protocol using field-programmable gate array based processor nodes and a custom-designed memory controller. The processor communicates all-optically with multiple synchronous dynamic random access memory nodes using 4 × 2.5-Gb/s wavelength-striped payloads, operating error free with bit-error rates less than 10-12.
Subtle, Pervasive, Harmful: Racist and Sexist Remarks in Public as Hate Speech

Using field observations and 100 in-depth interviews with participants recruited from public places in Northern California, this article documents the experience of being the target of hate speech in public places. Focusing on racist and sexist hate speech (as participants define the phenomenon), I show that there is a range of experiences with hate speech and that it is often quite subtle, leaving all but intended victims unaware that it occurs. These data also show that such interactions occur with regularity and leave targets harmed in significant ways. There can be little doubt that members of traditionally disadvantaged groups face a strikingly different reality on the street than do members of privileged groups. Although the legal status of hate speech remains ambiguous, its harms are not.
Edge-based segmentation of 3-D magnetic resonance images

The 3-D visualization of MR images of the brain requires that the data set first be segmented into brain and non-brain regions. Most existing segmentation techniques either require multiple-modality data (making high-resolution imaging impractical) or require extensive user interaction (for correction of contours). We present an automated technique for the segmentation of single-modality, 3-D magnetic resonance (MR) images. Computer graphics techniques ace employed to generate 3-D views of the brain's surface from the segmented images. The segmentation algorithm is based on the 3-D difference of Gaussians (DOG) filter. A novel method was developed for the classification of regions found by the DOG filter, as well as an automated correction procedure that detects errors from the DOG filter. Spatial information is also incorporated to help discriminate between tissues. Encouraging results were obtained with an average of less than five percent error in each image. >
Neural net based digital halftoning of images

Various novel techniques for digital image halftoning are presented, performing nonstandard quantization subject to a fidelity criterion. Hopfield-type networks can be used for this task, minimizing a frequency-weighted mean squared error between the input (continuous-tone) and the output (bilevel) image. A novel kind of massively parallel analog network (the differential neural network) is introduced and shown to be appropriate for this task. This kind of network contains a nonmonotonic nonlinearity in lieu of the sigmoid function. >
Surgical therapy for heart failure

Today’s healthcare delivery system is challenged with an escalating number of heart failure patients who have exhausted medical therapy and overwhelmed the limits of organ transplantation. Scientific and technological advances over the last 20 years have now brought new surgical options to this vast patient population, ranging from ventricular restoration surgery to surgical gene therapy and beyond. This article reviews the myriad of surgical options that are available to these patients, their benefits and shortcomings, as well as potential future directions.
The Age-Associated Decline of Glycogen Synthase Kinase 3β Plays a Critical Role in the Inhibition of Liver Regeneration

Aging reduces the regenerative capacities of many tissues. In this paper, we show a critical role of the glycogen synthase kinase 3β (GSK3β)-cyclin D3 pathway in the loss of the regenerative capacity of the liver. In young animals, high levels of growth hormone (GH) increase expression of GSK3β, which associates with cyclin D3 and triggers degradation of cyclin D3. In livers of old mice, the GSK3β promoter is repressed by C/EBPβ-histone deacetylase 1 (HDAC1) complexes, leading to the reduction of GSK3β. The treatment of old mice with GH increases expression of GSK3β via removal of the C/EBPβ-HDAC1 complexes from the GSK3β promoter. We found that the GSK3β-cyclin D3 pathway is also altered in young GH-deficient Little mice and that treatment of Little mice with GH corrects the GSK3β-cyclin D3 pathway. We present evidence that GSK3β regulates liver proliferation by controlling growth-inhibitory activity of C/EBPα. The downregulation of GSK3β in young mice inhibits liver proliferation after partial hepatectomy via the cyclin D3-C/EBPα pathway, while the elevation of GSK3β in old mice accelerates liver proliferation. Thus, this paper shows that GSK3β is a critical regulator of liver proliferation and that the reduction of GSK3β with age causes the loss of regenerative capacities of the liver.
Delayed-rectifier (KV2.1) regulation of pancreatic β-cell calcium responses to glucose: inhibitor specificity and modeling

The delayed-rectifier (voltage-activated) K+ conductance (KV) in pancreatic islet β-cells has been proposed to regulate plasma membrane repolarization during responses to glucose, thereby determini...
Localized refractory dissolved organic carbon sinks in the deep ocean

[1] The global ocean holds one of Earth's major carbon reservoirs as dissolved organic matter (662 ± 32 PgC). Most of this material (>95%) is termed refractory dissolved organic carbon (RDOC) as Williams and Druffel (1987) found it to be old relative to the circulation time of the ocean. While RDOC within the modern ocean is thus perceived as vast and only slowly renewed, its mobilization has been implicated by Sexton et al. (2011) to explain Earth's transient warming events (i.e., hyperthermals) of the Paleocene and Eocene epochs (65–34 million years ago). Assessing this proposed function of RDOC as a rapidly (~5–10 kyr) exchangeable carbon reservoir is presently limited by insufficient knowledge of the responsible processes. Here we investigate the dynamics of RDOC in the deep Pacific Ocean, previously characterized by concentration gradients thought to be established by slow but systematic RDOC removal with circulation and aging of the water masses. We demonstrate that RDOC is instead conserved during much of its circulation, but that there exist localized sinks in the deep, far North Pacific and at mid depth in the subtropical South Pacific. Water mass mixing into these sink regions creates the observed RDOC gradients. Together, the Pacific sinks remove 7–29% of the 43 Tg RDOC added to the deep global ocean each year with overturning circulation, and point to an important but still unidentified control on the RDOC inventory of deep marine systems.
Amplifiers, filters and geomorphic responses to climate change in Kentucky rivers

Efforts to predict responses to climate change and to interpret modern or paleoclimate indicators are influenced by several levels of potential amplifiers, which increase or exaggerate climate impacts, and/or filters, which reduce or mute impacts. With respect to geomorphic responses and indicators, climate forcings are partly mediated by ecological, hydrological, and other processes which may amplify or filter impacts on surface processes and landforms. Then, geomorphic responses themselves may be threshold-dominated or dynamically unstable, producing disproportionately large and long-lived responses to climate changes or disturbances. Or, responses may be dynamically stable, whereby resistance or resilience of geomorphic systems minimizes the effects of changes. Thus a given geomorphic response to climate could represent (at least) two levels of amplification and/or filtering. An example is given for three fluvial systems in Kentucky, U.S.A, the Kentucky, Green, and Big South Fork Rivers. Climate impacts in the early Quaternary were amplified by glacially-driven reorganization of the ancestral Ohio River system to the North, and by dynamical instability in the down-cutting response of rivers incising plateau surfaces. Effects of more recent climate changes, however, have been filtered to varying extents. Using alluvial terraces as an example, the study rivers show distinctly different responses to climate forcings. The lower Green River has extensive, well-developed terraces recording several episodes of aggradation and downcutting, while the Big South Fork River has no alluvial terraces. The Kentucky River is intermediate, with limited preservation of relatively recent terraces. The differences can be explained in terms of differences among the rivers in (1) filtering effects of constraints on fluvial responses imposed by strongly incised, steep-walled bedrock controlled valleys; and (2) amplifier effects of periodic damming of lower river reaches by glaciofluvial outwash.
‘The West and the Rest’: A Civilizational Mantra in Arms Control and Disarmament?

AbstractThis article attempts to reflect on arms control and disarmament as a civilizational practice. The provocation for this undertaking can be traced back to the growing popularity of civilization discourses. The article highlights the paradoxical tension within these discourses with, on the one hand, their proclamations of inter-civilizational conflicts based on failure to regulate and prohibit the proliferation of weapons and, on the other hand, the teleological drive towards building a universal civilization of modernity. It critiques these discourses with the help of critical security studies and postcolonial insights into the problematique of civilization that seeks to universalize that which stabilizes and asserts the military superiority of the West while marginalizing the efforts of ‘the Rest’ demanding equality and justice in practices of arms control and disarmament. The article then uses representative historical narratives to demonstrate the historical continuity between practices of discr...
Image Reconstruction from Undersampled Fourier Data Using the Polynomial Annihilation Transform

Fourier samples are collected in a variety of applications including magnetic resonance imaging and synthetic aperture radar. The data are typically under-sampled and noisy. In recent years, $$l^1$$l1 regularization has received considerable attention in designing image reconstruction algorithms from under-sampled and noisy Fourier data. The underlying image is assumed to have some sparsity features, that is, some measurable features of the image have sparse representation. The reconstruction algorithm is typically designed to solve a convex optimization problem, which consists of a fidelity term penalized by one or more $$l^1$$l1 regularization terms. The Split Bregman Algorithm provides a fast explicit solution for the case when TV is used for the $$l^1$$l1 regularization terms. Due to its numerical efficiency, it has been widely adopted for a variety of applications. A well known drawback in using TV as an $$l^1$$l1 regularization term is that the reconstructed image will tend to default to a piecewise constant image. This issue has been addressed in several ways. Recently, the polynomial annihilation edge detection method was used to generate a higher order sparsifying transform, and was coined the "polynomial annihilation (PA) transform." This paper adapts the Split Bregman Algorithm for the case when the PA transform is used as the $$l^1$$l1 regularization term. In so doing, we achieve a more accurate image reconstruction method from under-sampled and noisy Fourier data. Our new method compares favorably to the TV Split Bregman Algorithm, as well as to the popular TGV combined with shearlet approach.
Magnetic Ceramics: VI, Evaluation of Some Methods of Nickel Ferrite Formation

The extent of nickel ferrite formation, as affected by four preparatory techniques, was investigated by determining the magnetic moment of the reacted powder with a vibrating-coil magnetometer. The oxide, carbonate, hydroxide, and oxalate methods were used. At low temperatures the hydroxide and oxalate techniques were found to give the greatest yield of ferrospinel. The hydroxide method yielded a magnetic material by precipitation. Weight-loss measurements were correlated to the magnetic data.
On-chip high-power porous silicon lithium ion batteries with stable capacity over 10000 cycles (Presentation Recording)

We demonstrate the operation of a graphene-passivated on-chip porous silicon material as a high rate lithium ion battery anode with over 50x power density and 100x energy density improvement compared to identically prepared on-chip porous silicon supercapacitors. We demonstrate this Faradaic storage behavior to occur at fast charging rates (1-10 mA/cm2) where lithium locally intercalates into the nanoporous silicon, but not underlying bulk silicon material. This prevents the degradation and poor cycling performance that is commonly observed from deep storage in bulk silicon materials. As a result, this device exhibits cycling performance that exceeds 10,000 cycles with capacity above 0.1 mAh/cm2, without notable capacity fade. This work demonstrates a practical route toward high power, high energy, and long lifetime all-silicon on-chip storage systems relevant toward integration of energy storage into electronics, photovoltaics, and other silicon-based technology.
Spectrin’s chimeric E2/E3 enzymatic activity

In this minireview, we cover the discovery of the human erythrocyte α spectrin E2/E3 ubiquitin conjugating/ligating enzymatic activity and the specific cysteines involved. We then discuss the consequences when this activity is partially inhibited in sickle cell disease and the possibility that the same attenuation is occurring in multiple organ dysfunction syndrome. We finish by discussing the reasons for believing that nonerythroid α spectrin isoforms (I and II) also have this activity and the importance of testing this hypothesis. If correct, this would suggest that the nonerythroid spectrin isoforms play a major role in protein ubiquitination in all cell types. This would open new fields in experimental biology focused on uncovering the impact that this enzymatic activity has upon protein-protein interactions, protein turnover, cellular signaling, and many other functions impacted by spectrin, including DNA repair.
Passive SCR for lean gasoline NOX control: Engine-based strategies to minimize fuel penalty associated with catalytic NH3 generation

Abstract Lean gasoline engines offer greater fuel economy than common stoichiometric gasoline engines. However, excess oxygen prevents the use of the current three-way catalyst (TWC) to control nitrogen oxide (NOX) emissions in lean exhaust. A passive SCR concept, introduced by General Motors Global RD however, the rich operation necessary for NH3 production results in a fuel consumption penalty. The fuel penalty can be minimized by adjusting spark timing to increase rich-phase engine out NOX emissions and, thereby, NH3 levels. Additionally, higher engine out NOX during engine load increase to simulate acceleration resulted in additional fuel savings. A 10% fuel consumption benefit was achieved with the passive SCR approach by optimizing rich air-fuel equivalence ratio and spark timing while also utilizing acceleration load conditions.