cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure and organization of membrane organelles along distal microtubule segments in growth cones.

Advance and stabilization of organelle-rich cytoplasm within the neuronal growth cone is coupled to axon elongation (Goldberg and Burmeister, 1986; Aletta and Greene, 1988), and this involves forward movement of organelles from the growth cone base along distinct tracks toward the leading edge. Membrane-bound organelles that advance first within the growth cone often make transient excursions toward the leading edge, and at the light microscope level these leading organelles appear to colocalize with distal microtubule (MT) segments (Dailey and Bridgman, 1989). We have used electron microscopy (EM) to identify the membranous organelles adjacent to distal MT segments, and to examine their structural interactions with MTs. In both glutaraldehyde-fixed and rapid frozen whole-mount growth cones, attenuated endoplasmic reticulum (ER)-like membrane elements were the most common organelle type located adjacent to distal MT segments. These ER-like membrane elements coursed roughly parallel to MTs and frequently terminated within an electron-dense bulb at the MT tip. Blind-ended membrane tubes, dense-core vesicles, clear vesicles, and vacuoles were also found adjacent to distal MT segments. Quantitative analyses of organelle-MT associations suggest that elements of the ER-like membrane system may frequently advance ahead of other membrane-bound organelles. Freeze-etch EM revealed crossbridging structures between MTs and membranous organelles, which is consistent with the idea that advance of leading membrane organelles into the growth cone periphery is mediated by microtubule-based motor transport mechanisms. The results suggest that distal microtubule segments serve as transport elements for advance of membrane organelles into more peripheral growth cone regions, and together MTs and ER-like membrane organelles may initiate the conversion of dynamic F-actin-rich cytoplasm to more stable organelle-rich cytoplasm (i.e., axoplasm).
On the decidability and axiomatization of query finiteness in deductive databases

A database query is finite if its result consists of a finite sets tuples. For queries formulated as sets of pure Horn rules, the problem of determining finiteness is, in general, undecidable.In this paper, we consider superfiniteness—a stronger kind of finiteness, which applies to Horn queries whose function symbols are replaced by the abstraction of infinite relations with finiteness constraints (abbr., FC's). We show that superfiniteness is not only decidable but also axiomatizable, and the axiomatization yields an effective decision procedure. Although there are finite queries that are not superfinite, we demonstrate that superfinite queries represent an interesting and nontrivial subclass within the class of all finite queries.The we turn to the issue of inference of finiteness constraints—an important practical problem that is instrumental in deciding if a query is evaluable by a bottom-up algorithm. Although it is not known whether FC-entailment is decidable for sets of function-free Horn rules, we show that super-entailment, a stronger form of entailment, is decidable. We also show how a decision procedure for super-entailment can be used to enhance tests for query finiteness.
Co-chairman's remarks: genome organization and evolution.

Abstract A full understanding of the evolution of life on the earth must include an account of the RNA world and of any other informational systems that preceded it.
Response to Comment on "Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment"

Although Chan makes several valid points, his analysis confuses relationships associated with the long-term variations with those associated with shorter term variability (interannual and decadal). We present an analysis that clarifies the observations from the western North Pacific.
Energy use quantification in the canning of Clingstone peaches

Thermal and electrical energy usages in a California clingstone peach cannery were monitored to establish energy consumption levels and to identify energy intensive unit operations. Representative processing lines were instrumented with orifice plates for steam flow measurements and with electric watt transducers for electrical power monitoring to yield actual consumption values. Steam use in the lye peelers and retorts accounted for 98% of all energy consumed, indicating that further examination of these operations for modification or equipment redesign should be a first priority for energy conservation. Pumping of liquids and dry conveying of fruit and waste material accounted for 61% of all electrical energy use. Electrical energy use amounted to only 2% of the total energy used, however, on an equivalent fossil fuel use basis.
The Act of Killing

The Act of Killing. Joshua Oppenheimer, director; Signe Byrge Sorensen, producer. Featuring Anwar Congo, Jusuf Kalla, etc. Produced by Final Cut for Real, Denmark, 2012; 159 or 115 mins. Available ...
Ensemble Kalman filters for large geophysical applications

At the same time that the Kalman filter (KF) was being developed, the United States produced its first operationally useful numerical weather prediction in 1958 using a single-layer barotropic model. Over the next 40 years, incredible increases in computing power have allowed numerical weather prediction (NWP) models to become far larger and more comprehensive so that modern models have tens of millions of state variables. Throughout this period, operational NWP models always taxed the capabilities of the largest computer systems available.
Cam-Clay plasticity, Part II: implicit integration of constitutive equation based a nonlinear elastic stress predictor

Abstract An improved stress integration algorithm for the modified Cam-Clay plasticity model capable of accounting for nonlinear elasticity is proposed. The algorithm entails the use of secant elastic moduli for integrating the nonlinear elastic constitutive equation in conjunction with a fully implicit scheme for calculating plastic strains. Numerical experiments demonstrate the algorithm's good accuracy and stability under a wide variety of imposed stress and strain paths. This algorithm should be useful in situations dominated by combined nonlinear elastic unloading and plasticity such as would occur in tunneling and excavations.
Identification and Characterization of TF1phox, a DNA-binding Protein That Increases Expression of gp91phox in PLB985 Myeloid Leukemia Cells

The CYBB gene encodes gp91phox, the heavy chain of the phagocyte-specific NADPH oxidase. CYBB is transcriptionally inactive until the promyelocyte stage of myelopoiesis, and in mature phagocytes, expression of gp91phox is further increased by interferon-γ (IFN-γ) and other inflammatory mediators. The CYBB promoter region contains several lineage-specific cis-elements involved in the IFN-γ response. We screened a leukocyte cDNA expression library for proteins able to bind to one of these cis-elements (−214 to −262 base pairs) and identified TF1phox, a protein with sequence-specific binding to the CYBB promoter. Electrophoretic mobility shift assay with nuclear proteins from a variety of cell lines demonstrated binding of a protein to the CYBB promoter that was cross-immunoreactive with TF1phox. DNA binding of this protein was increased by IFN-γ treatment in the myeloid cell line PLB985, but not in the non-myeloid cell line HeLa. Overexpression of recombinant TF1phox in PLB985 cells increased endogenous gp91phox message abundance, but did not lead to cellular differentiation. Overexpression of TF1phox in myeloid leukemia cell lines increased reporter gene expression from artificial promoter constructs containing CYBB promoter sequence. These data suggested that TF1phox increased expression of gp91phox.
Value of serum arabinitol for the management of Candida infections in clinical practice.

To determine the value of serum arabinitol concentrations in clinical practice, we identified all patients at the University of Utah Medical Center for whom a serum arabinitol determination had been requested by the attending physician or housestaff to assist in the management of candidiasis. The patient populaton was divided into three categories on the basis of clinical and pathological findings: (1) superficial candidiasis, (2) possible deep, invasive candidiasis, and (3) definite, deep invasive candidiasis. Abnormal renal function was associated with elevated concentrations of serum arabinitol in proportion to the degree of renal dysfunction. Both the serum arabinitol concentration and the arabinitol/creatinine ratio were increased in the combined patient population with candidiasis relative to normal uninfected controls (p=0.06 and 0.001, respectively). However, neither of these tests reliably distinguished patients with invasive candidiasis from those with only superficial candidal disease.
Explanation for False-positive Urine Cultures Obtained by Bag Technique

We would like to thank Drs Robson and Leung for their comments. As they state, our study does not support the use of bag specimens for the diagnosis of UTIs because a bag specimen results in a high false-positive rate. A bag specimen may be useful, however, when the physician would like to examine the urine in a healthy infant and is willing to withhold antibiotics until urine culture results are reported. If the culture is positive for pathogens, it may be a reflection of the periurethral flora, or it may mean that the urinary tract is infected. To differentiate between periurethral colonization of urine and a UTI, an in-and-out catheter or suprapubic aspiration is recommended for specimen collection. Obviously, if antibiotic therapy has already begun, the diagnosis of periurethral colonization of the urine vs UTI will be impossible to differentiate. Urine bag collection is reliable only if
Conjoint Analysis of Study Abroad Preferences: Key Attributes, Segments and Implications for Increasing Student Participation

ABSTRACT An adaptive conjoint analysis was performed on the study abroad preferences of a sample of undergraduate college students. The results indicate that trip location, cost, and time spent abroad are the three most important determinants of student preference for different study abroad trip scenarios. The analysis also uncovered four different study abroad need-based segments. In order to increase study abroad participation rates it is recommended that universities determine which of these segments they want to target, and then develop a set of study abroad offerings and communication strategies custom designed to address the particular needs of each targeted segment. Recommendations on how to market to each segment are provided.
A multispecies chemistry model of Io's local interaction with the Plasma Torus

[1] We model the local interaction between the plasma in the torus and Io's neutral corona (inside ∼6 RIo), focusing on the multispecies chemistry outside the collision-dominated ionosphere. We include a detailed chemistry of S, O, SO2, SO under ionization, charge exchange, and recombination processes in a parcel of plasma that follows a prescribed flow field around Io's ionosphere and interacts with the neutral density profiles in the corona, as constrained by available observations. We compare the model results to the Galileo plasma observations in Io's wake (GLL/J0). We conclude the following: (1) The plasma characteristics along GLL/J0 require a dense SO2 corona confined close to Io (<2 RIo). (2) Molecular SO2 chemistry dominates the interaction, with atomic chemistry playing a negligible role. (3) SO2+ is the main output ion of the local interaction, but it recombines and dissociates rapidly so that the contribution of the local interaction to the global mass and energy supply of the torus is very small. (4) The high density of plasma observed in the wake requires a supplemental ionization source beyond the thermal electrons of the torus, and we estimate the ionization due to the (∼350 eV) field-aligned electron beams observed around Io. (5) Assuming a SO2 atmosphere/corona with a vertical column of 6 × 1016 cm−2 and a prescribed deceleration of the flow around Io, we estimate a local ion mass production rate of ∼200 kg/s. We also compute a neutral loss rate of ∼2400 kg/s and a pick-up current of ∼5.2 MAmp, both dominated by the SO2 resonant charge exchange reaction.
Inflammatory cytokines and antigen presenting cell activation

Immune responses are stimulated in response to threats against health. In animals, defense against infectious agents, particularly rapidly growing viruses and bacteria, requires an immediate response to limit growth and dissemination, and then stimulation of a more prolonged, specific immunity to prevent re-infection. The process by which animals meet the dual needs of an immediate response to danger and initiation of long-term protection is substantially influenced by inflammatory cytokines produced primarily by macrophages and professional antigen presenting cells (APCs). Inflammatory cytokines mobilize the immune system in response to danger and increase the efficiency of an immune response as effectors of APC function. Here we review the evidence for the involvement of inflammatory cytokines in immune induction and as mediators of APC activity, with a particular emphasis on swine and on the induction of immunity at mucosal surfaces. The vast majority of infections occur at mucosal surfaces of the enteric, respiratory and reproductive tracts, and induction of protective immunity at these sites is particularly challenging. Induction of immunity at mucosal surfaces of the small intestine is greatly facilitated by the oral adjuvant, cholera toxin (CT). CT potentiates inflammatory cytokine and costimulatory molecule expression in macrophages, and stimulates humoral and cell-mediated immune responses both locally and systemically. These observations are consistent with the hypothesis that activation of APCs is a key step in the induction of antigen-specific immunity, and that inflammatory cytokine expression is a hallmark of activated APC function. The efficacy of vaccine adjuvants, particularly in the context of mucosal immunity, may be determined by their ability to induce a controlled inflammatory response in gut-associated lymphoid tissue, characterized by the expression of various costimulatory molecules and inflammatory cytokines. Thus, elucidation of the patterns of inflammatory cytokine expression and features of APC activation will help to facilitate the rational development of more efficacious vaccines.
Further remarks on boundary conditions of plasma models in a bounded region

The field solutions for a parallel-plate waveguide filled with warm plasma in the zero-temperature limit are examined in detail. The results show that a complete consistency of these solutions with those for the cold plasma cannot be obtained.
Cognitive development of learners in pharmacy education

Abstract Human development involves growth and maturation, including development in the cognitive abilities of learners. Just as Jean Piaget's childhood stages of cognitive development have provided a basis for kindergarten through 12th-grade education, cognitive development theories for adults in higher education have been described. Kohlberg's theory in developmental psychology, Grow's model of self-directed learning, Saljo's conceptions of learning, and Vygotsky's theory of social development are discussed in relation to cognitive development of student pharmacists. Importantly, not all learners appear to progress through all stages in these cognitive theories, with some learners progressing further than others. Investigations suggest that learners in any course of study are not all in the same stage of development; development stages can vary among classmates. Cognitive development theories suggest that educators should assess course requirements and foster development for diverse learners. Likewise, student definitions of learning can be simple or complex, though appear to mirror the instructor's teaching methods and learning definition. Thus, deeper learning requires skilled educators to strive in understanding and challenging learners toward greater cognitive development. Important to cognitive development are strategies for improving thinking and a manner in which educators can augment both course instructional format and students' conceptions of learning. Implications to pharmacy education are discussed, such as educators' need to plan for increasing cognitive abilities among students progressing through a whole pharmacy program. All pharmacy educators should have a conceptual basis for cognitive development of learners in pharmacy.
Carbamazepine Regulates Feline Aggression Elicited From the Midbrain Periaqueductal Gray

Carbamazepine has been utilized both as an anticonvulsant and as a psychotropic drug for the treatment of complex partial seizures and various mood and other emotional disorders such as the episodic dyscontrol syndrome. In the present study, we sought to identify the role of carbamazepine in the regulation of two forms of aggressive behavior--affective defense and quiet biting attack behavior--elicited by electrical stimulation of the midbrain periaqueductal gray matter of the cat in the absence of convulsive activity. The experimental paradigm involved establishment of stable baseline thresholds for affective defense and quiet biting attack responses. Following establishment of a stable baseline, carbamazepine (2.5, 5, or 10 mg/kg) and propylene glycol (vehicle control) were administered peripherally (IP). The response thresholds were tested 5-30, 30-60, 60-90, 120-150, 1440-1470, and 2160-2190 minutes following drug administration. It was observed that carbamazepine administration at 5 and 10 mg/kg dose levels preferentially suppressed affective defense behavior but had no effect upon quiet biting attack, indicating that the selective effects of carbamazepine upon affective attack are not due to any possible sedative effects upon motor responses. The effects of carbamazepine upon affective defense were dose dependent and of long duration when administered at the highest dose level (10 mg/kg).
Environmental heat and partial water restriction effects on body fluid spaces, water loss, body temperature, and metabolism of Holstein cows.

Abstract The effects of partial water restriction on metabolism, body fluid compartments, and water balance were measured in seven mature nonlactating Holstein cows at two constant environmental temperatures, 18 and 32C. For 7 days at each temperature, water was restricted to 50% of ad libitum consumption. Partial water restriction at 18C caused a 50% reduction in water loss with a reduction in total body fluid volume mainly from the extravascular fluid compartment. This was followed by a reduction in feed consumption and metabolism. At 32C partial water restriction caused a great reduction in water loss through urine and feces, allowing more of the water to be used for heat loss by vaporization. Partial water restriction, unlike total water withdrawal, did not change the volumes of vascular compartments at either normal or high temperatures. However, animals exposed to normal and high temperatures respond differently to water restriction. At 18C similar percentage reductions (approximately 50%) occur in urine, fecal water, and total vaporization to reduce water loss during water restriction. But at 32C water loss is reduced mainly by reduction of urine and fecal water, rather than vaporization. Comparison between ad libitum animals at the two temperatures showed that heat caused a 15.9% reduction in metabolism. Water restricted cows, compared to ad libitum cows at 32C, showed a 17.0% reduction in metabolism. Results suggest the reduced metabolism is a compensatory mechanism to reduce internal heat production in an environment of high external heat and low water availability. Also, insignificant reduction in blood and plasma volumes produced available fluids for heat loss through vaporization when water was restricted at a high temperature.
Modeling of sputtering erosion/redeposition—status and implications for fusion design

This paper reviews sputtering erosion/redeposition modeling for plasma facing surfaces. Basics of the WBC Monte Carlo impurity transport code are described. An example analysis is shown for erosion of a liquid tin fusion reactor divertor. Multiyear erosion studies of candidate divertor and first wall coating materials (Li, Be, C, W, etc.) are summarized—showing generally serious erosion concerns for low-Z solid materials, and encouraging results for high-Z materials and liquid divertor surfaces. Future goals are discussed, e.g. for supercomputer modeling.
Fast-Atom Bombardment Mass Spectrometry Coupled to Planar Gel Electrophoresis

Abstract An interface system between planar gel electrophoresis and mass spectrometry is described that includes a means of rapid electrophoretic gel disruption, concentration of extracted sample in a pre-column, and transfer of the sample molecules to the continuous flow FAB source of a mass spectrometer. Spatial resolution achieved on the surface of the gel is on the order of 2 mm diameter for a spot, and 4 mm2 for a band. Sensitivities to 50 picomoles have been demonstrated for the analysis of small peptides with continuous-flow fast atom bombardment mass spectrometry.
Continuous or intermittent cocaine administration: Effects of amantadine treatment during withdrawal

Research indicates that daily cocaine injections produce sensitization to, while the continuous infusion of cocaine produces tolerance to, its behavioral and neurochemical effects. The effects of the continuous infusion of cocaine are consistent with the withdrawal syndrome reported by human cocaine abusers. The present experiment examined whether amantadine administrations during withdrawal from continuous or intermittent cocaine attenuate and/or eliminate the behavioral effects produced by these administration regimens. The rats were pretreated for 14 days with either continuous or intermittent daily injections of cocaine, and were then withdrawn from the pretreatment regimen for 7 days. On days 1-5 of the withdrawal period, half the subjects received a 5.0 mg/kg IP injection of amantadine, and the other half received a 20.0 mg/kg IP injection of amantadine. On day 7 of withdrawal from the cocaine pretreatment, all rats were given a 15.0 mg/kg IP injection of cocaine. Their behavior was rated according to the modified Ellinwood and Balster (6) scale for 60 min. The results indicated that amantadine treatment during withdrawal eliminated the tolerance normally associated with the continuous infusion of cocaine. In contrast, in both the saline control and daily injection subjects amantadine treatment during withdrawal resulted in a slight, but statistically significant, reduction in the behavioral effects of cocaine. The present results therefore indicate that low doses of amantadine should be considered as a potential pharmacotherapy for the early stages of cocaine withdrawal. Furthermore, the present experimental procedures may represent an effective screening methodology for potential cocaine pharmacotherapies.
Enrichments of aquatic bacteria in continuous culture

A chemostat was employed for the enrichment and eventual isolation of a variety of heterotrophic bacteria from seawater. Experimental attempts to separate single species from mixed cultures of known composition showed that successful or unsuccessful competition for the limiting substrate is based upon the particular growth parameters of the individual species under the given culture conditions. The technique appears to be suitable to enrich reproducibly for bacterial species of little substrate specificity. Applications in ecological studies are discussed.
Factor VLeiden Inhibits Fibrinolysis In Vivo

Background— Factor VLeiden (fVLeiden) predisposes to thrombosis by enhancing thrombin formation. This study tested the hypothesis that fVLeiden inhibits fibrinolysis in vivo. Methods and Results— Radiolabeled clots were injected into the jugular veins of wild-type mice and mice heterozygous (fV+/Q) or homozygous (fVQ/Q) for fVLeiden. Mean percent clot lysis 5 hours later was significantly reduced in fVQ/Q mice (14.3±3.6%, n=13) compared with wild-type mice (40.2±7.0%, n=17; P<0.01) and intermediate in fV+/Q mice (29.4±8.7%, n=9; P<0.03 versus fVQ/Q, P=0.36 versus wild type). The rate of in vitro lysis of plasma clots prepared from fV+/Q or fVQ/Q mice was significantly slower than that of wild-type plasma clots, whereas in vitro clot lysis did not differ significantly between groups after inhibiting thrombin-activatable fibrinolysis inhibitor. Conclusions— fVLeiden inhibits fibrinolysis in vivo, suggesting an additional pathway by which this mutation promotes thrombosis.
A simple model for the sorption of helium by Fullerene crystals

Abstract We propose a simple model to explain the start of intercalation of helium atoms into Fullerene polycrystals. The result of our analysis shows that for both 3 He and 4 He to intercalate into the Fullerene, they must overcome a barrier of 7K above the vacuum.
An improved method for estimating surface humidity from daily minimum temperature

Abstract Minimum daily air temperature (Tn) is often used as a surrogate for mean daily dew point (TI,day) to estimate near-surface humidity. This method is unreliable under arid conditions where nightly minimum temperatures may remain well above the dew point. Daily meteorological data from 52 weather stations within the continental US and Alaska were evaluated. Daily differences between Td,day and Tn were large in arid climates, with corresponding vapor pressure differences averaging between 0.8 and 1.2 kPa on an annual basis. Sites with semi-arid characteristics showed a large degree of seasonality in the results with average vapor pressure differences ranging from 0.1 to 0.6 kPa between winter and summer months. Sites in other climate regimes generally showed small differences between Tn and Td,day over the entire year, corresponding to average vapor pressure differences of less than 0.3 kPa. An empirical model was developed to improve the accuracy of Tn based humidity estimates using daily air temperature, annual precipitation and estimated daily potential evapotranspiration. The model reduced humidity estimation errors by up to 80% at semi-arid and arid sites and had minimal effects when Tn based humidity estimates were relatively accurate. The ratio of annual precipitation to estimated annual evapotranspiration was useful for distinguishing sites where Tn based humidity estimates were relatively accurate from sites where estimation errors were large. The results of this investigation provide a simple, more accurate method than Tn for estimating humidity in arid and semi-arid regions using general weather station data.
Iridium thin films deposited via pulsed laser deposition for future applications as transition-edge sensors

The University of Miami has recently started developing and studying high-resolution microcalorimeters operating near 100 mK for X-ray and particle physics and astrophysics. These detectors will be based on Transition Edge Sensors technology fabricated using iridium thin films deposited via the Pulsed Laser Deposition technique. We report here the preliminary result of the room temperature characterization of the Ir thin films, and an overview of future plans to use the films as transition edge sensors.
SU-GG-T-48: Clinical Implementation of Electronic Brachytherapy Skin Applicator in IORT Setting

Purpose: Commissioning of a skin applicator for a 50kVp electronic source for an expeditious IORT treatmentMethod and Materials: A single applicator cone (50mm diameter, 31.4mm SSD) was used with a 50kVp source to produce a circular field. The field was collimated using disposable cutouts (0.5mm lead equivalent) between 1cm × 1cm and 1cm × 4.9cm. Treatment margins were derived to ensure a 5% dose deviation, using GAFChromic film. Cutout factors, chamber stem effect, and the effect of imperfect Cone‐Skin contact were investigated using a soft x‐ray chamber. Results: Without the cutout, the treatment margin was found to be 0.9mm. Adding cutouts, the margin was 0.4mm for a 10mm field, and 2.1mm for a 45mm field. The stem effect was as high as 0.8% for elongated cutouts. A 10% dose rate decrease was measured 1mm away from the end cap. The cutout factors range was 3.7%. Physical abutment of two fields on the skin could increase dose up to 44%, while a 1mm gap/overlap caused −60%/+60% dose variations, respectively. Conclusion: In an IORT setting, it is necessary to provide proper cutout and treatment time as quickly as possible. Based on our measurements, a cutout can be produced on the fly in the OR by conservatively adding 2mm around the measured scar. It is not necessary to measure individual cutout factors, as the dose delivered using an averaged cutout factor should be within 5% of the measured value. Given the 10%/mm dose rate drop away from the applicator, it is imperative to position the lesion at a known and stable treatment position for maintaining contact between cutout and skin. When treating areas greater than 5cm, the overlap region could experience ∼60% dose variations. Study partially supported by a Xoft, Inc. grant.
Cortical areas supporting category learning identified using functional MRI

Functional MRI was used to identify cortical areas involved in category learning by prototype abstraction. Participants studied 40 dot patterns that were distortions of an underlying prototype and then, while functional MRI data were collected, made yes-no category judgments about new dot patterns. The dot patterns alternated between ones mostly requiring a “yes” response and ones mostly requiring a “no” response. Activity in four cortical areas correlated with the category judgment task. A sizeable posterior occipital cortical area (BA 17/18) exhibited significantly less activity during processing of the categorical patterns than during processing of noncategorical patterns. Significant increases in activity during processing the categorical patterns were observed in left and right anterior frontal cortex (BA 10) and right inferior lateral frontal cortex (BA 44/47). Decreases in activation of visual cortex when categorical patterns were being evaluated suggest that these patterns could be processed in a more rapid or less effortful manner after the prototype had been learned. Increases in prefrontal activity associated with processing categorical patterns could be related to any of several processes involved in retrieving information about the learned exemplars.
Linearized Optical Tomography using the Diffusion Approximation in Regions with Curved Boundaries

We show that the diffusion approximation with a zero partial-flux boundary condition accurately models photon migration in a highly scattering medium with curved boundaries. In particular, we examine optical mammography in a transmission geometry.
MALDI tissue imaging of ocular lens alpha-crystallin.

PURPOSE: To apply MALDI (matrix-assisted laser desorption ionization) tissue imaging methods to obtaining a profile of the distribution of the lens alpha-crystallins and their modified forms in calf and mature bovine lenses. METHODS: Frozen bovine lenses were cut equatorially at -12 degrees C to -20 degrees C into 10- to 40-microm sections depending on lens age. Tissue sections were mounted onto MALDI sample plates by ethanol soft-landing to maintain tissue integrity. A two-layered matrix deposition method was used to improve mass spectral reproducibility across sections. Molecular images of the two subunits of alpha-crystallin and their modifications over approximately one-half of a single tissue section were reconstituted from mass spectral data sets acquired in 250-microm steps. Identification of protein truncation products and confirmation of phosphorylation distribution patterns were performed by reverse-phase liquid chromatography of soluble extracts from specific tissue regions followed by tandem mass spectrometry (LC/MS/MS). RESULTS: Distinct distribution patterns were observed for the two subunits of alpha-crystallin and their modified forms. alphaA-crystallin showed extensive truncation across whole sections, especially in the nuclei, whereas alphaB-crystallin was observed to be relatively stable. Both alphaA-crystallin and alphaB-crystallin displayed the highest level of phosphorylation in the middle cortex region, a finding confirmed by LC/MS/MS analysis of dissected regions. CONCLUSIONS: A new imaging technique has been successfully applied to molecularly characterize the spatial distribution of lens proteins and their modifications in lens sections. The different distributions of alpha-crystallin revealed in this study provide new leads in the investigation of underlying physiological significance of the modified forms of the two alpha-crystallin subunits.
A Source of Response Regulator Autophosphatase Activity: The Critical Role of a Residue Adjacent to the Spo0F Autophosphorylation Active Site †

Two-component signaling systems are used by bacteria, plants, and lower eukaryotes to adapt to environmental changes. The first component, a protein kinase, responds to a signal by phosphorylating the second component; a response regulator protein that often acts by inducing the expression of specific genes. Response regulators also have an autophosphatase activity that ensures that the proteins are not permanently activated by phosphorylation. The magnitude of this activity varies by at least 1000-fold between various response regulators, and the molecular features responsible for this varied autophosphatase activity have not been clearly defined. Using wild-type and mutant derivatives of the sporulation response regulator Spo0F, it has been demonstrated that a key residue in determining the magnitude of this activity is that at position 56 of Spo0FP; this residue is adjacent to the site of phosphorylation, Asp 54. For example, Spo0FP K56N has a 23-fold greater autophosphatase activity (t1/2 ) 8 min) than wild-type Spo0F P( t1/2 ) 180 min). It is suggested that, by analogy to the GTPase activity of p21 ras and by examining the crystallographic structure of Spo0F, that the carboxyamide of the mutant Asn 56 may favorably position a catalytic water near the protein acyl phosphate to promote Spo0FP K56N hydrolysis. It is also deduced that Lys 56 in the wild-type protein is critical for the efficient interaction and phosphoryl transfer between Spo0F and it's cognate protein kinase, KinA. Comparison of the known response regulators shows that inefficient autophosphatases ( t1/2 on the order of hours) typically contain an amino acid residue with a long side chain at the position equivalent to 56 in Spo0F, whereas efficient autophosphatases (t1/2 on the order of minutes) frequently contain a residue with a carboxyamide or carboxylate side chain at this position. It appears that, by altering residues adjacent to the active site, the autophosphatase activity of response regulator proteins has been attenuated to match the diverse biological roles played by these proteins.
Nanoparticle adhesion in proton exchange membrane fuel cell electrodes

Abstract Carbon supported platinum (Pt/C) catalyst remains among the most preferable catalyst materials for Proton Exchange Membrane (PEM) fuel cells. However, platinum (Pt) particles suffer from poor durability and encounter electrochemical surface area (ESA) loss under operation with the accompany of Pt nanoparticle coarsening. Several proposed mechanisms have involved the Pt detachment from its carbonate support as an initial step for the deactivation of Pt nanoparticles. In this study, we investigated the detachment mechanism from the nano-adhesion point of view. Classic molecular dynamics simulations are performed on systems contain Pt nanoparticles of different sizes and shapes. A thin Nafion film (1 nm) at different hydration levels is also included in the system to study the environmental effect on nanoparticle adhesion. We found that the adhesion force strengthens as the Pt size goes up. Pt nanoparticles of tetrahedral shape exhibit relatively stronger connection with the carbon substrate due to its unique ‘anchor-like’ structure. Adhesion is enhanced with the introduction of a Nafion. The humidity level in the Nafion film has a rather complicated effect on the strength of nanoparticle adhesion. The binding energies and maximum adhesive forces are reported for all systems studied.
Monitoring the synthesis and properties of copolymeric polycations.

Abstract The kinetics; evolution of molar mass; solution conductivity, sigma; intrinsic viscosity; and average composition drift; and distribution were determined by monitoring the synthesis of copolymeric polycations of acrylamide (Am) and [2-(acryloyloxy)ethyl]-trimethylammonium chloride (Q9). The quantitative relationship between diminishing sigma and charged co-monomers incorporation was monitored for the first time and provided novel data on counterion condensation, which occurs gradually over a broad composition regime. This new capability allows predictions concerning the relationship between copolymer composition and linear charge density, xi, to be tested and models of trivariate mass, composition, and xi distributions to be built. This approach, hence, brings together the previously disparate fields of synthetic chemistry of copolymers and physical chemical properties of polyelectrolytes. Monitoring was achieved with a new implementation of the ACOMP (automatic continuous online monitoring of polymerization reactions) platform. Reactivity ratios determined by ACOMP were rQ9 = 0.47 and rAm = 1.10. Opposite trends in composition drift and final molar mass were found; low starting percentage of Q9 led to low composition drift and high molar mass, whereas the opposite was found at high starting percentage of Q9. Complementary end-product analysis by multidetector gel permeation chromatography supported the ACOMP results. End-product polyelectrolyte properties were characterized by automatic continuous mixing, revealing that combined electrostatic persistence length and excluded volume effects led to the expected large changes in polyelectrolyte conformation and interactions. These results set the groundwork for semibatch control of molar mass, composition, and xi, and eventually for monitoring and control for inverse emulsion-based reactions of this type.
Preparation of long-chain β-enaminones and β-diketones from long-chain 3,5-disubstituted isoxazole compounds

A series of long-chain compounds containing the β-enaminone functionality were prepared in yields ranging from 71 to 88% from their corresponding long-chain 3,5-disubstituted isoxazole precursors utilizing a Raney nickel-catalyzed reductive ring-opening procedure. These newly prepared multifunctional compounds were subsequently hydrolyzed under mild acidic conditions (pH 4–5) to give their corresponding long-chain β-diketones in yields ranging from 79 to 98%. Both the β-enaminone and β-diketone functionalized compounds were characterized by NMR, IR spectroscopy, GC-MS, and m.p. The mass spectra for these two classes of compounds, derived by utilizing electron impact ionization, gave distinctive McLafferty rearrangement fragmentation ions that clearly established the newly introduced functionality to reside at the C-2 and C-4 positions of the lipid’s alkyl chain. 1H NMR spectra of the pure β-diketone compounds were complex owing to the keto enol tautomerism displayed by the β-diketone moiety. In solution the β-diketone compounds were shown to exist mainly in the enolic tautomeric form. Long-chain β-diketone compounds are known to be relatively common constituents of some plant waxes, and the overall procedure starting from soybean methyl esters provides a complementary approach to prepare these types of compounds.
Rayleigh-Ritz Calculation of Effective Potential Far from Equilibrium

We demonstrate the utility of a Rayleigh-Ritz scheme recently proposed to compute the nonequilibrium effective potential nonperturbatively in a strong noise regime far from equilibrium. A simple Kramers model of an ionic conductor is used to illustrate the efficiency of the method.
Does Depression Cause Obesity? A Meta-analysis of Longitudinal Studies of Depression and Weight Control

To evaluate the causal effects of depression on obesity, longitudinal tests of the effect of depression on follow-up obesity status were meta-analyzed. Combining data from 16 studies the results confirmed that, after controlling for potential confounding variables, depressed compared to nondepressed people were at significantly higher risk for developing obesity. The risk among depressed people for later obesity was particularly high for adolescent females (odds ratio: 2.57, 95% CI: 2.27, 2.91). These findings highlight the importance of depression screening and treatment programs, especially among adolescents, to assist in the prevention of adult obesity.
Frequency-domain measurements of changes of optical pathlength during spreading depression in a rodent brain model

Previously, we have shown that time-resolved spectroscopy can monitor changes in the distribution of photon migration pathlengths which are reflective of the changes in the tissue absorption due primarily to oxygenated or deoxygenated hemoglobin. In this study, we have monitored mean photon migration pathlengths in the frequency domain in the rodent brain insulted by hypoxia, ischemia and spreading depression (SD) using phase modulated spectroscopy (PMS). This technique consisted of monitoring light which emerged from the exposed rodent skull at 8 mm form an incident light source of 754 nm and 816 nm whose intensity was modulated at 220 MHz. The changes in phase-shift, (theta), of the emergent light with respect to the incident light are reflective of the photon pathlengths and hemoglobin absorbance. A multiprobe assembly holding PMS source fiber, nicotinamide dinucleotide (NADH) fluorometric probe, electrocortigraph (ECoG) electrodes, and doppler blood flow probe was placed on the rodent brain to simultaneously monitor brain metabolism, electrical cortical activity (ECoG) and blood flow. The PMS detector fiber was placed 8 mm posterior to the multiprobe assembly. Correlations between changes in intracellular deoxygenation (NADH) and hemoglobin deoxygenation as measured by PMS changes at 754 nm and 816 nm during hypoxia, and ischemia were found. The depolarization phase of spreading depression resulted in a similar increase at both 754 nm and 816 nm. We attribute this result to vasoconstriction and/or the decrease of extracellular space due to water shift in the rodent brain.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Are centrifugal ventricular assist devices the answer to reducing post-implantation gastrointestinal bleeding?

Ventricular assist devices (VAD) are an effective and innovative strategy for prolonging the life of patients with end-stage congestive heart failure. However, significant rates of post-implantation nonsurgical bleeding continue to challenge the management of these patients [(1)][1]. Over the last
Morphometric analysis of horizontal canal nerves of chronically diabetic rats.

Horizontal canal nerves of 3-, 6-, 9-, and 12-month-diabetic rats were compared with those of age-matched controls. The myelin sheaths of the horizontal canal nerves in diabetic rats were thinner t...
Quenching the wild wells of Kuwait

We have attempted to provide an analysis of the problems and constraints related to controlling the types of wild wells encountered in Kuwait. We hope that new ways of dealing with such catastrophes will emerge from our discussion. But it is difficult to prepare for a disaster that is likely to happen to somebody else, in a community in which interests are divided and even opposed. In the case of Kuwait, there have certainly been missed opportunities. For instance, if a share in the future production of several wells had been given to one company (and that replicated tenfold), with the proviso that the methods used to control their wells would be available to be practiced by others, progress might have been made more rapidly and with higher confidence. As $50 million a day was being lost in Kuwait, considerable money could have been saved by a fast response to the problem. Not only have important resources been destroyed by the action of Iraq, they have been unnecessarily squandered by an inability to permit technical measures to be implemented to control the wild wells of Kuwait.
Use of the Spectrophotometer for Measuring Melanin Dispersion in the Frog

Summary(1) The spectrophotometer has been used as an instrument for recording the effects of melanophore expansion on the reflecting power of the skin pigments of the frog. (2) The reflectance in the light adapted frogs may be as much as 10% above that of the dark adapted frog at the same wave length. (3) Melanophore expansion in dark adapted frogs masks the reflecting power of the skin pigment at the red end of the spectrum more than at the violet. (4) The average skin reflectance in the light adapted frogs is not more than 21.8%. (5) A difference between the response of melanophores to environmental conditions and operations of the hypophysis is suggested.
Solar ponds using ammonium salts

Abstract Ammonium salts have good potential for use in salt gradient solar ponds. The environmental problems associated with NaCl are eliminated by incorporating the salt discharge from the solar pond into the fertilizer cycle of an agricultural system. Thermophysical and optical properties of several ammonium salts are sufficiently close to those of NaCl to suggest that the thermal efficiency of solar ponds using ammonium salts should be equivalent to that of a NaCl pond. Ammonia outgassing is minimal, and algae growth is curtailed by precipitating soluble phosphates. Because fertilizer is purchased for the agricultural system, the cost of salt for the solar pond is determined by the real interest for holding the fertilizer in inventory. These economics make feasible several desirable maintenance schedules for the solar pond.
“All These People Who Can Do Things That I Can’t”: Adolescents’ Reflections on Class, Poverty, and the American Dream

This article investigates high school seniors’ attitudes about socioeconomic status in two historical contexts: the growing economy of the mid-1990s and the recent economic recession. High school seniors (N = 72) were provided with identical scenarios and questions that prompted them to evaluate social stratification. The 1996 cohort expressed belief in the American Dream and individual mobility whereas the 2011 cohort articulated more understanding of structural issues that affect social class mobility. Analysis showed greater awareness of the economy’s impact on family life in the 2011 cohort. Finally, the 2011 cohort noted the strong role of technology as an indicator of status.
A New Nanotechnology Technique for Determining Drug Efficacy Using Targeted Plasmonically Enhanced Single Cell Imaging Spectroscopy

Recently, we described a new technique, targeted plasmonically enhanced single cell imaging spectroscopy (T-PESCIS), which exploits the plasmonic properties of gold nanoparticles, e.g. gold nanospheres, to simultaneously obtain enhanced intracellular Raman molecular spectra and enhanced Rayleigh cell scattering images throughout the entire span of a single cell cycle. In the present work, we demonstrate the use of T-PESCIS in evaluating the relative efficacy and dynamics of two popular chemotherapy drugs on human oral squamous carcinoma (HSC-3) cells. T-PESCIS revealed three plasmonically enhanced Raman scattering vibration bands, 500, 1000, and 1585 cm–1, associated with the cellular death dynamics. Detailed analysis indicated that the decrease in the 500 cm–1 band did not correlate well with drug efficacy but could indicate death initiation. The time it takes for the relative intensity of either the 1000 or 1585 cm–1 band (“SERS death” bands) to appear and increase to its maximum value after the injecti...