cssi/SciSciGPT-SciSciNet huggingface dataset:
Importance of Potassium in Patients With Acute Myocardial Infarction

The records of 151 patients entering a coronary care unit and subsequently diagnosed as having an acute myocardial infarction were reviewed. The prevalence of hypokalemia, its relationship to diuretic treatment and the development of either ventricular tachycardia or ventricular fibrillation were studied. At admission, 14% of patients were hypokalemic. The presence of hypokalemia was related to previous diuretic therapy. Twenty-three percent of patients receiving diuretics as compared to 7% of patients not taking diuretics had a serum potassium of 3.5 mEq/L or less. Thirty-seven patients experienced either ventricular tachycardia or ventricular fibrillation. The presence of hypokalemia was associated with an increased frequency of both of these arrhythmias. Sixty-seven percent of patients with a serum potassium of less than 3.1 mEq/L had these serious ventricular arrhythmias compared to 40% of patients with a serum potassium between 3.1 and 3.5 mEq/L and 20% of normokalemic patients. The prevalence of premature ventricular beats was not correlated with the presence of hypokalemia. We conclude that hypokalemia is not only a common problem in patients with acute myocardial infarction but a clinically significant factor in the development of life threatening arrhythmias. Primary prevention of hypokalemia and its prompt treatment are indicated in these patients.
Ultrafast Charge Separation and Recombination Dynamics in Lead Sulfide Quantum Dot–Methylene Blue Complexes Probed by Electron and Hole Intraband Transitions

Lead salt quantum dots (QDs) have emerged as attractive materials for solar energy conversion because of their broad spectral response, long exciton lifetime, and efficient multiexciton generation. However, charge separation dynamics from these QDs remain poorly understood. In this study we investigate charge separation and recombination dynamics in PbS–methylene blue (MB+) complexes by femtosecond transient absorption spectroscopy. We show that while the 1S electrons and holes in excited PbS QDs lead to overlapping transient absorption features in the visible and near-IR regions, their intraband absorptions in the mid-IR can be monitored independently to directly follow the charge separation and recombination processes. The charge separation and recombination rates in PbS-MB+ complexes were found to be (2.7 ± 0.2) × 1012 and (1.1 ± 0.2) × 1011 s–1, respectively. The ultrafast charge separation rate suggests the possibility of hot electron injection and multiexciton dissociation from these strongly quantu...
Information access: Toward a more robust conceptualization

Information access is implicated in multiple research areas in library and information science (LIS). This paper argues that information access should receive more explicit attention from researchers. First, the two predominant conceptualizations of information access are examined and synthesized, noting the particular strengths and weaknesses of each. Next, the paper illustrates the centrality of information access by examining several LIS research areas; this explication demonstrates that information access is an important, though often implicit, concern of LIS researchers. Information access is studied across several research areas, but these typically remain isolated and unconnected. By integrating multiple analytical approaches to information access, this paper improves upon the current understanding of information access. The brief examination of information access suggests that a more refined framework, incorporating additional dimensions, would be fruitful, both to promote research into information access and to better integrate disparate research streams. This paper has three goals: to draw attention to the centrality of information access across LIS, to incorporate multiple research streams' perspectives on information access, and to suggest further refinements to the study of information access.
Glycolate biosynthesis by Scenedesmus and Chlorella in the presence or absence of NaHCO3

Both Scenedesmus and Chlorella excreted comparable quantities of glycolate. Glycolate formation was dependent upon light and oxygen, but occured in the absence of added CO2 or NaHCO3 for net photosynthesis. In an environment of 3000 ft. c. light and an atmosphere of oxygen, about 35 μg glycolate were excreted per hour per milliliter 1% (v/v) algae without NaHCO3 or CO2. Upon addition of NaHCO3 the rate increased to about 55 μg. Glycolate formation in the light in the absence of CO2 may result from photometabolism of algal polysaccharides. Glycolate excretion by Scenedesmus occurred at all pH values between 6.5 and 9.5 and was not related to utilization of bicarbonate. Scenedesmus obliquus excreted glycolate when existing in plates of four or eight cells, but not when present as small individual cells. At pH 9 14C fixation by Scenedesmus was faster than fixation by Chlorella. There was no significant difference in products of 14C fixation formed by Scenedesmus at pH values between 6.5 and 9.5. For unknown reasons α-hydroxy-2-pyridinemethanesulfonate stimulated CO2 fixation by Scenedesmus by at least 100%. This sulfonate had no effect on glycolate excretion nor upon the distribution of 14C among the products of 14CO2 fixation by Scenedesmus.
Ebic characterization of HgCdTe crystals and photodiodes

The scanning electron microscope was used to evaluate crystal imperfections and surface conditions of HgCdTe photovoltaic detectors by the electron induced current technique. This nondestructive technique, which can be applied to other semiconductor sensors as well, was found to be useful in examining the optically active area of the devices both at room and low temperatures. Marks as small as 0.05Μm due to imperfections in the detector material and improper surface preparation can clearly be observed. Devices are examined with and without antireflecting coating. Poor adhesion and pin hole defects in the dielectric can also be detected by this technique. Damage introduced by device fabrication is identified. The induced signal image characterization is compared to surface examinations by SEM operating in the secondary electron image mode and by x-ray topography.
Urinary N-Sulfate Glycosaminoglycan Excretion in Children: Normal and Abnormal Values.∗†

SummaryAn assay for N-sulfate hexosamine has been adapted to the determination of the urinary excretion of N-sulfated glycos-aminoglycans. Values were obtained for N-sulfate glycosaminoglycan concentrations in the urine of 56 pediatric outpatients without clinical signs of mucopolysaccharidosis. Abnormal levels of N-sulfate glycosaminoglycan were found in 6 cases of mucopolysaccharidosis.
Interferon-gamma (IFN-γ) regulates production of IL-10 and IL-12 in human herpesvirus-6 (HHV-6)-infected monocyte/macrophage lineage

To determine whether HHV-6 infection induces expression and production of IL-10 and IL-12 in monocytes/macrophages, and to explore the influence of IFN-γ on cytokine production in HHV-6-infected cells, expression and production of IL-10 and IL-12 were evaluated through reverse transcription-polymerase chain reaction (RT-PCR) and sandwich ELISA. HHV-6 infection induced the expression and the production of IL-10 and IL-12 in monocytes and THP-1 cells. Kinetic study showed that the expression of IL-12 mRNA decreased with accumulation of IL-10 mRNA. Expression and production of IL-12 were markedly increased when anti-human IL-10 MoAbs were added to the cultures, implying that endogenous IL-10 induced by HHV-6 inhibited IL-12 production. Addition of increasing concentrations of IFN-γ to the cultures of HHV-6-infected cells enhanced the expression of IL-12 gene, while the accumulation of IL-10 mRNA was down-regulated. Determination of protein levels of IL-10 and IL-12 by ELISA also showed that IFN-γ increased IL-12 and decreased IL-10 production. These results suggest that IFN-γ regulates the production of IL-10 and IL-12 at transcriptional level mainly through inhibiting endogenous IL-10 production in HHV-6-infected monocyte/macrophage lineage.
Compound scaling algorithm for multiobjective functions

: In this paper the possibility of using compound scaling algorithm for solving the multiobjective optimization problem is demonstrated. The algorithm treats the objective functions similar to behavior constraints during the intermediate iterations of optimization. The algorithm generates a partial Pareto curve while solving the problem. Truss and plate structures are used as example problems.
Computational methods based on an energy integral in dynamic fracture

Developments in the use of the crack tip energy flux integral in computational dynamic fracture mechanics over the past few years are reviewed. An expression for the crack tip energy flux in terms of near tip mechanical fields which is valid for general material response is derived. It is then demonstrated that certain useful energy integrals may be extracted from the general result by invoking the appropriate characterization of material response. Several alternative representations of energy flux in the form of integrals over some finite region around the crack tip are presented and compared with a view toward implementation in finite element simulation studies.
Biodegradation of Chlorinated Ethenes

Biodegradation of chlorinated ethenes by naturally occurring or artificially enhanced processes is an important component of current site remediation strategies. At this writing, several microbial mechanisms for chlorinated ethene transformation and degradation have been identified. The purpose of this chapter is to briefly summarize the current understanding of those processes that lead to the biodegradation of chlorinated ethenes.
Immunogenic potential of rgp120 from African HIV-1 subtype A

Previous studies have shown that the African strains of HIV-1 mostly cluster with the subtypes A, C or D based on phylogenetic analysis of the ENV nucleotide sequences. In the present investigation we have examined the immunogenic potential of full length gp120 derived from the Ugandan HIV-1 subtype A isolate, AUG06c, using computer-based prediction methods and a plasmid-mediated immunization technique. Computer-assisted analysis of the amino acid residues identified 15 potential B-cell epitopes in gp120 of AUG06c. Despite marked variation in the primary sequences, these epitopes were shown to correspond well to analogous sites in gp120 derived from the subtype B reference clones, MN and IIIBBH10. The relative positions of the epitopes indicated that E9[V3], E14[C3] and E15[V5] correspond to the previously defined principal neutralizing determinant (PND) located in the V3 loop, the CD4 binding site and gp120 "immunodominant" region, respectively. Intramuscular inoculation of BALB/c mice with the ENV clones from AUG06c or from the subtype C clone, CUG045 elicited antibodies which react with the homologous but not with the heterologous PND peptide in ELISA. However, cocktail inoculation with the ENV plasmids from AUG06c and CUG045 elicited antibodies which reacted with both peptides. Antibody response to the other predicted epitopes of AUG06c was not as strong as the response to the PND peptide. The response of the mice to DNA-mediated immunization was further tested in a proliferation assay. Spleen cells derived from the immunized mice exhibited a strong proliferative response to homologous and heterologous PND peptides in [3H]thymidine incorporation assay. DNA-mediated immunization with rgp120 of AUG06c appears to elicit cellular immune response of relatively broad specificity.
Multi-UAV System for Inventory Automation

This paper discusses the high-level design considerations and implementation challenges of an RFID-reader-equipped multi-UAV (unmanned aerial vehicle) system to aid inventory automation in a warehouse. A preliminary simulation, employing probabilistic-like algorithm for navigation decision, was also conducted to visualize the feasibility of the system.
New insights in solving distributed system equations by the quadrature method—I. Analysis

Abstract This paper provides new insights in solving distributed system equations by the method of differential quadrature (Bellman et al., 1972). In this study, the method is shown to be essentially equivalent to the general collocation method (Finlayson and Scriven, 1966). Explicit formulae of the quadrature coefficients are derived for arbitrarily-distributed nodes and for nodes located at the zeros of an orthogonal polynomial. Due to their simplicity and flexibility, these formulae allow us to calculate the values of the coefficients accurately and efficiently. Since the accuracy of the equation solutions depends on the locations of the nodes, a systematic procedure for placing the grid points is developed. In Part II of this paper, this proposed approach is demonstrated to be superior than that of the orthogonal collocation. Methods for approximating partial derivatives in a symmetric problem are also proposed to minimize the computational effort. The above techniques are then extended to cases in which the given partial differential equation and associated constraints can not be transformed into an initial-value problem. Instead of the conventional approach of converting the problem into a large set of algebraic equations, a two-point boundary-value problem is formulated to reduce the number of iteration parameters. This strategy is especially suitable for cases with highly nonlinear equations.
Quantitative description of plastic deformation in nanocrystalline Cu: Dislocation glide versus grain boundary sliding

Uniaxial plastic deformation of polycrystalline Cu with grain sizes in the range of 5--20 nm was studied by using molecular dynamics computer simulations. We developed a quantitative analysis of plasticity by using localized slip vectors to separate the contributions of dislocation activity from grain boundary sliding. We conclude that the competition between these two mechanisms depends on strain rate and grain size, with the dislocation activity increasing with grain size but decreasing with increasing strain rate. For samples with a 5 nm grain size, dislocations contribute $\ensuremath{\approx}50%$ of the total plastic strain during steady state deformation at a rate of $1\ifmmode\times\else\texttimes\fi{}{10}^{8}\text{ }{\text{s}}^{\ensuremath{-}1}$, but this fraction decreases to 35% at a rate of $1\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }{\text{s}}^{\ensuremath{-}1}$. When the grain size is increased to 20 nm, dislocations account for 90% of the strain, even at $1\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }{\text{s}}^{\ensuremath{-}1}$. During the initial stages of plastic deformation, grain boundary sliding initially decreases with strain owing to strain-induced relaxation processes within the grain boundaries. The grains also rotate a few degrees during straining to 20%; the rate of rotation (per unit strain) slightly decreases with strain rate. Lastly, we computed the amount of forced atomic mixing during plastic deformation. The mean square separation distance between atom pairs within grain interiors increases with strain at a rate proportional to their distance apart (i.e., the mixing is superdiffusive), but for pair separations greater than the grain size, this rate becomes independent of the separation distance.
Lactate Shuttling and Lactate use as Fuel after Traumatic Brain Injury: Metabolic Considerations:

Lactate is proposed to be generated by astrocytes during glutamatergic neurotransmission and shuttled to neurons as ‘preferred' oxidative fuel. However, a large body of evidence demonstrates that metabolic changes during activation of living brain disprove essential components of the astrocyte–neuron lactate shuttle model. For example, some glutamate is oxidized to generate ATP after its uptake into astrocytes and neuronal glucose phosphorylation rises during activation and provides pyruvate for oxidation. Extension of the notion that lactate is a preferential fuel into the traumatic brain injury (TBI) field has important clinical implications, and the concept must, therefore, be carefully evaluated before implementation into patient care. Microdialysis studies in TBI patients demonstrate that lactate and pyruvate levels and lactate/pyruvate ratios, along with other data, have important diagnostic value to distinguish between ischemia and mitochondrial dysfunction. Results show that lactate release from human brain to blood predominates over its uptake after TBI, and strong evidence for lactate metabolism is lacking; mitochondrial dysfunction may inhibit lactate oxidation. Claims that exogenous lactate infusion is energetically beneficial for TBI patients are not based on metabolic assays and data are incorrectly interpreted.
Spatio-temporal characterization of the equatorial electrojet from CHAMP, Ørsted, and SAC-C satellite magnetic measurements

Received 4 May 2007; revised 20 June 2007; accepted 12 June 2007; published 13 September 2007. [1] The equatorial electrojet (EEJ) is an eastward electric current on the day-side, flowing in a narrow band along the dip equator in the ionospheric E region. Recent magnetic observations from the CHAMP, Orsted, and SAC-C satellites, comprising more than 95,000 dip equator crossings from 1999 to 2006, have provided an unprecedented longitudinal coverage of the EEJ magnetic signature. We have used these data to construct an empirical model of the EEJ current climatological mean and day to day variability as a function of longitude, local time, season, and solar flux. Our model has been successfully verified against vertical drift data from the JULIA radar at Jicamarca. We have also used the EEJ observations to estimate the self-correlation of the EEJ, confirming short longitudinal correlation lengths of 15 and finding a temporal correlation length of 2.4 h. Our model’s predictions of the eastward electric field and its standard deviation may provide useful input to various kinds of ionospheric simulations. Coefficients and software are available online at http://models.geomag.us/EEJ.html and http://www.earthref.org.
Delay efficient opportunistic routing in asynchronous multi-channel cognitive radio networks

In this paper, we are interested in designing efficient distributed opportunistic routing protocols for multi-hop multi-channel cognitive radio networks (CRNs). In CRNs, secondary users (SUs) access unused primary channels opportunistically, which induces considerable end-to-end delays for multi-hop routing. The primary cause of the delay overhead is that the set of available channels change dynamically over time due to the activities of primary users, making it challenging to effectively explore the spectrum diversity. Our approach towards working with such a dynamic network is to construct a cross-layer distributed opportunistic routing protocol. Our protocol jointly considers the channel sensing strategy, the forwarder selection for each SU, and the package division scheme on each link. We mathematically model the expected delay of each hop along the routing path. This delay model sheds lights on our expected end-to-end delay analysis, from which we develop a distributed algorithm to derive the system parameters for the opportunistic routing protocol. Extensive simulation results indicate the improved performance of our opportunistic routing protocol in terms of end-to-end delay, especially for CRNs with highly dynamic channel conditions.
Weitere Untersuchungen über Musterbildung in Kombinaten aus teilweise dissoziierten Flügel-Imaginalscheiben von Drosophila melanogaster

Zusammenfassung 1. 1. Flugel-Imaginalscheiben aus verpuppungsreifen Larven von Drosophila melanogaster wurden durch Trypsinbehandlung in vitro in eine Suspension von Einzelzellen bis Zellgruppen von weniger als hundert Zellen dissoziiert. 2. 2. Dabei wurden zwei Mutanten verwendet: yellow ( y , gelbe Korper- und Borstenfarbe) und multiple wing-hairs ( mwh , anstelle der einfachen Spreitenhaare auf der Flugelflache stehen Buschelchen von 2–5 Harchen). 3. 3. Zellen aus dissoziierten Scheiben wurden folgendermassen gemischt und reaggregiert: y;mwh + mit y + ; mwh , und reziprok y + ; mwh + mit y;mwh . 4. 4. Die so erhaltenen, gemischten Aggregate wurden in Wildtyplarven implantiert. 5. 5. Die implantierten Aggregate metamorphosieren zu Flugelspreiten-Mosaiken mit normalen, aus y und y + Borsten bestehenden Randborsten-Mustern (Abb. 1 und 2). Die Morphologie der die Randborsten umgebenden Spreitenhaare ( mwh + resp. mwh ) beweist, dass diese Randborsten-Mosaike echt sind und nicht durch teilweise nichtautonome Verfarbung von einheitlichen yellow Arealen verstanden werden konnen. Solche nicht-autonome Verfarbung kommt allerdings vor. 6. 6. Die Verwendung der Mutante mwh erlaubt, die Reichweite der nicht-autonomen Verfarbung von yellow -Bereichen durch angrenzende y + Areale festzustellen (Abb. 6). 7. 7. In den Aggregaten bildeten sich auch Thorax-Mosaike (Abb. 3). In diesen verhalten sich die yellow Borsten autonom. 8. 8. Oft werden unvollstandige Randborsten-Muster gebildet; in solchen Mosaiken sind die Randborsten alle entlang einer ausgesprochenen Achse angeordnet (Abb. 5). 9. 9. Die Zellen teilen sich nach der Dissoziation noch mehrmals. Dadurch wird das implantierte Material vervielfacht. Einzelzell-Mosaike sind dementsprechend selten. 10. 10. Der Metamorphosebeginn der Wirtslarven wird durch die Implantate oft hinausgeschoben. 11. 11. Die Ergebnisse werden im Hinblick auf Eigenschaften von morphogenetischen Feldern und Vormustern in Imaginalscheiben diskutiert.
The Project Method Approach: An Integrated Teaching Tool in Marketing Research

This article discusses the integrative role of the project method approach in marketing research. Using the six-step framework of the marketing research process, the article illustrates the effective execution of the project method approach and shows how the project method not only fosters at least 10 useful managerial skills but also incorporates the traditional lecture, case analysis, and games and simulation approaches to teaching marketing. Limitations of the project method and some observations on alternative approaches to its implementation are discussed.
Citrate as a regulator of acetyl-CoA metabolism in liver mitochondria

Abstract 1. 1.|The reversibility of citrate synthesis and the effects of citrate and fluorocitrate on citrate synthesis in whole mitochondria have been investigated. 2. 2.|Cleavage of citrate to oxaloacetate (trapped as malate) and acetyl-CoA (trapped as acetylcarnitine) in whole liver mitochondria can be demonstrated. The maximum rate of this reversed reaction is at most 1 40 of the maximum rate of citrate synthesis. 3. 3.|Citrate and fluorocitrate are competitive inhibitors with respect to oxaloacetate of purified pig heart synthase. The K i for both compounds was found to be approx. 1.5 mM. 4. 4.|Both citrate and fluorocitrate inhibit citrate synthesis and increase ketogenesis in whole liver mitochondria. They probably act as competitive inhibitors with respect to oxaloacetate, since malate counteracts this inhibition. 5. 5.|For kinetic reasons it is concluded that the citrate synthesis reaction probably never approaches equilibrium in the intact tissue. The importance of citrate in the regulation of citrate and ketone body formation in the liver is discussed.
Green's function for the Helmholtz equation in a layered half-space

In this article we construct the three-dimensional Green's function for Helmholtz's equation in a layered half-space.
Enhancement of seminiferous tubular growth and spermatogenesis in testes of rats recovering from early hypothyroidism: a quantitative study.

Testicular weight and DNA content were markedly reduced (63 and 69%) in weanling Long-Evans rat pups rendered hypothyroid from birth by administration of propylthiouracil (PTU), a reversible goitrogen. These growth deficits worsened to >80% by continuing hypothyroidism beyond weaning, to days 50 and 90. Recovery of thyroid function, brought about by discontinuing PTU at weaning, resulted in a paradoxical stimulation of testis growth, amounting to increased weight (40%), DNA content (60%) and size by 90 days, compared to age-matched controls. In the 25-day or older hypothyroid rats, testicular structure was immature and spermatogenesis markedly delayed, as evident by closed lumen and significantly reduced diameter of seminiferous tubules (38%), thickness of germinal layer (70%), and number of primary spermatocytes (86%), compared to control. Hypothyroidism did not alter the number of tubules per testis cross section. In the 90-day recovery rats, numbers of seminiferous tubules were unchanged but tubular diameter was significantly (20%) larger than in controls and spermatogenesis appeared very active as indicated by significantly increased germinal layer thickness (22%) and total number and density of primary spermatocytes (55% and 40%). The results show that although postnatal hypothyroidism is deleterious for testicular growth and spermatogenesis, recovery from this condition leads to enhanced seminiferous tubular growth and spermatogenesis.
Diurnality and cone photopigment polymorphism in strepsirrhines: examination of linkage in Lemur catta.

Trichromatic color vision is routine among catarrhine primates, but occurs only as a variant form of color vision in some individuals in most platyrrhine genera. This arises from a fundamental difference in the organization of X-chromosome cone opsin genes in these two lineages: catarrhines have two opsin genes specifying middle- and long-wavelength-sensitive cone pigments, while platyrrhines have only a single gene. Some female platyrrhine monkeys achieve trichromacy because of a species polymorphism that allows the possibility of different opsin gene alleles on the two X-chromosomes. Recently, a similar opsin gene polymorphism was detected in some diurnal strepsirrhines, while at the same time appearing to be absent in any nocturnal genera. The aim of this study was to assess whether cone pigment polymorphism is inevitably linked to diurnality in strepsirrhines. Cone photopigments were measured in a species usually classified as diurnal, the ring-tailed lemur (Lemur catta), using electroretinogram flicker photometry, a noninvasive electrophysiological procedure. Each of 12 animals studied was found to have the same middle-wavelength cone pigment, with peak sensitivity at about 547 nm. In conjunction with earlier results, this implies that cone pigment polymorphism is unlikely to exist in this species and that, accordingly, such variation is not a consistently predictable feature of vision in diurnal strepsirrhines.
The role of blood group antigens in infectious diseases

The medical literature contains a large number of publications attempting to correlate blood groups with disease. Many of these reports are poorly documented and have limited scientific validity. Only a few agents, such as malaria parasites and parvovirus B19, infect red blood cells (RBCs) and precursors. Most other agents use RBCs as carriers to the target tissue. There is an excess of blood group A individuals among cancer patients compared with normal individuals; malignancy has also been associated with the Lewis antigen. Plasmodium vivax only enters RBCs when the Fy6 Duffy protein is present. Certain Escherichia coli organisms will only attach to epithelial cells carrying P or Dr blood group antigens. The P antigen Is also the receptor for parvovirus B19. Le(b) appears to be the receptor for Helicobacter pylori in gastric tissue. The high frequency blood group antigen AnWJ is the receptor for Haemophilus influenzae. Knowledge of the functions of RBC surface molecules Is expanding and the ability to generate experimental animals devoid of certain molecules will clarify their physiological role.
Membrane permeability changes with vitamin A/vitamin E mixed bilayers

Abstract Vitamin A (all trans -retinol) enhances the permeability of egg phosphatidylcholine liposomes to glucose, urea, and erythritol while vitamin E (α-tocopherol) decreases permeability to the same solutes. Egg phosphatidylcholine bilayers containing both vitamin A and vitamin E are shown to have an altered permeability more similar to that affected by vitamin E alone. The membrane stabilizing effect of vitamin E appears dominant over the membrane destabilizing effect of vitamin A.
Performance of a metallic gas diffusion layer for PEM fuel cells

A novel metallic porous medium with improved thermal and electrical conductivities and controllable porosity was developed based on micro/nano technology for its potential application in PEM fuel cells. In this work to demonstrate its applicability, the gas diffusion medium, made of 12.5 μm thick copper foil, was tested in an operational fuel cell. The small thickness and straight-pore feature of this novel material provides improved water management even at low flow rates. The performance does not decline at lower flow rates, unlike conventional gas diffusion layers. It has been shown that the performance can be further enhanced by increasing the in-plane transport. The improvements of such gas diffusion layer, including pore shape, porosity, and surface properties, are fully discussed.
A theory of rational childhood

Abstract This paper explores the implications of the extension of the assumption of rational self-interested maximization to children. This extension provides useful insights into the economic rationality of family interactions, beyond that possible when children are assumed to be ‘durable goods’. A number of childhood behavior patterns, often dismissed as childish irrationality, can be modeled as rational rent-seeking strategies within the family ‘marketplace’.
A Mutant Yeast Topoisomerase II (top2G437S) with Differential Sensitivity to Anticancer Drugs in the Presence and Absence of ATP

To further characterize the mechanistic basis for cellular resistance/hypersensitivity to anticancer drugs, a yeast genetic system was used to select a mutant type II topoisomerase that conferred cellular resistance to CP-115,953, amsacrine, etoposide, and ellipticine. The mutant enzyme contained a single point mutation that converted Gly437 --> Ser (top2G437S). Purified top2G437S displayed wild-type enzymatic activity in the absence of drugs but exhibited two properties that were not predicted by the cellular resistance phenotype. First, in the absence of ATP, it was hypersensitive to all of the drugs examined and hypersensitivity correlated with increased drug affinity. Second, in the presence of ATP, top2G437S lost its hypersensitivity and displayed wild-type drug sensitivity. Since the resistance of yeast harboring top2G437S could not be explained by alterations in enzyme-drug interactions, physiological levels of topoisomerase II were determined. The Gly437 --> Ser mutation reduced the stability of topoisomerase II and decreased the cellular concentration of the enzyme. These findings suggest that the physiological drug resistance phenotype conferred by top2G437S results primarily from its decreased stability. This study highlights the need to analyze both the biochemistry and the physiology of topoisomerase II mutants with altered drug sensitivity in order to define the mechanistic bridge that links enzyme function to cellular phenotype.
Electric field dependence of the thermal conductivity of quantum paraelectrics

Thermal conductivity measurements have been carried out on single crystals of ${\mathrm{SrTiO}}_{3}$ and ${\mathrm{KTaO}}_{3}$ in the presence of electric fields applied either perpendicular or parallel to the heat current. In the case of ${\mathrm{SrTiO}}_{3},$ the response is surprisingly large: a 7 kV/cm parallel field increases the thermal conductivity by up to $400%.$ A pronounced anisotropy in both materials, which becomes apparent above nearly the same temperature, is also observed. These effects can be interpreted qualitatively using a simple model in which TA phonons in an energy band near the soft TO mode scatter off of either impurities, ferroelectric microregions, or quantum ferroelectric fluctuations.
The nuclear spin response to intermediate energy protons

Abstract Hadronic spin-excitations in nuclei are investigated by studying inelastic proton-nucleus scattering. The Random-Phase-Approximation (RPA) and the Distorted-Wave-Impulse-Approximation (DWIA) are used to describe the nuclear structure and reaction, respectively. To study spin-excitations in (p,p')-reactions, the double differential cross section and the spin-flip probability S nn ' are investigated for forward angles. The longitudinal and transverse spin-flip probabilities S L and S T give information about the π and ρ-exchange in the nuclear medium. These spin observables depend sensitively on the distortions of the projectile wave.
Colonoscopic full-thickness resection of the colon in a porcine model as a prelude to endoscopic surgery of difficult colon polyps: a novel technique (with videos)

Background Colonoscopic full-thickness resection (CFTR) of the colon may obviate the need for surgical resection of benign lesions. Objective To develop an animal model for CFTR of the colon followed by endoscopic suture closure with through-the-endoscope devices. Design Pilot study. Setting University medical center. Animals Twenty pigs. Interventions A 2-cm circular area was resected on the antimesenteric side of the colon (phase 1, n=10) and on the mesenteric side (phase 2, n=10) by using an insulated tip knife cut followed by the use of a grasping forceps and a snare to resect and retrieve the specimen. The tissue apposition system was used to close the defect. Main Outcome Measurements Resection and closure times were recorded. The animals were euthanized at 2 weeks and examined for peritonitis, adhesions, wound healing, and T-tag injury to adjacent viscera. Results The CFTR was successful in all 20 attempts. The median resection time was 6 minutes (range 2.5–35 minutes). Suture closure was successful in 19 animals. It took a median time of 41 minutes (range 21–125 minutes) and 4 sutures to close the defect. Eighteen animals survived without clinical signs of distress; there was a well-healed scar without peritonitis or distant adhesions on necropsy at 2 weeks. One animal failed to thrive, and necropsy revealed mild peritonitis, small abscesses, distant adhesions, and a 2-mm hole at the suture site. Two of the 132 T-tags were inserted in the adjacent viscera. Limitations Colon resection in the proximal colon was not studied. Conclusions In this animal model, CFTR of the colon followed by suture closure can be accomplished successfully by using through-the-endoscope devices.
The cyclization of N,N′-bis[2-(dialkoxy)ethyl]-p-xylene-α,α′-diamine dihydrochloride to pyrido[3,4-g]isoquinoline and 3,8-phenanthroline

The ring closure of N,N′-bis[2-(dialkoxy)ethyl]-p-xylene-α,α′-diamine dihydrochloride in fuming sulfuric acid has been investigated and the cyclization products have been identified as the linear pyrido[3,4-g]isoquinoline as well as the previously reported angular 3,8-phenanthroline.
Post-Ecdysial Change in the Permeability of the Exoskeleton of the Blue Crab, Callinectes Sapidus

Crustaceans must replace their old exoskeleton with a new, larger one in order to grow and differentiate. During that process a new (preexuvial) cuticle is deposited beneath the old cuticle. Since breakdown products from the old cuticle have been reported to be removed from the old cuticle and transported across the new cuticle and hypodermis into the hemolymph, the preexuvial cuticle is presumed to be permeable. However, it has also been reported that intermolt cuticle is a highly impermeable structure that prevents loss of water and ions from the cuticle to the external environment. This study was designed to determine the timing of any change in the permeability of the cuticle of the blue crab, Callinectes sapidus, from the period just preceding ecdysis through the early postmolt period. To test for any changes in permeability pilot studies were performed on pieces of dorsobranchial cuticle from late premolt (D4) and early postmolt crabs (15 min, 2 h, 12 h and 18 h post-ecdysis) using 3 H2O and an Ussing chamber. Additional permeability studies were done monitoring the movement of p-nitrophenol (pNP) across the cuticle using a more restricted post-exuvial time course (0, 5, 10, 15 and 30 min. postecdysis) as compared to premolt cuticle. Results from these studies as well as wash-out studies using tissues pre-loaded with pNP and staining of 1 h post-molt cuticle with OsO4 suggest that the epicuticle undergoes a transition at or soon after ecdysis that renders it impermeable to water and small molecules. While the precise mechanism for this transition is unknown, it is clear that the resultant alteration in epicuticle permeability during early post-ecdysis allows for the formation of a barrier that prevents osmotic and ionic exchange, allows for the generation of significant hydrostatic pressure, and provides a suitable microenvironment for calcification.
Web 2.0 Technologies: Applications for Community Colleges

The current generation of new students, referred to as the Millennial Generation, brings a new set of challenges to the community college. The influx of these technologically sophisticated students, who interact through the social phenomenon of Web 2.0 technology, bring expectations that may reshape institutions of higher learning. This chapter provides an overview of Web 2.0 technologies and considerations of their potential to transform the way education is delivered. Long-held learning beliefs and established educational strategies may need to be redefined to incorporate the benefits of Web 2.0 and to serve the educational needs of the Millennial Generation.
Cadmium carboxycinnamate coordination polymers with dimensionality differences depending on dipyridyl ligand

Hydrothermal reaction of cadmium nitrate, carboxycinnamic acid (H 2 cca), and a tethering hydrogen-bonding capable dipyridyl ligand afforded three new crystalline coordination polymers, which were characterized by single-crystal X-ray diffraction. {[Cd(cca)(dpa) 2 ]·2H 2 O} n ( 1 , dpa = 4,4′-dipyridylamine) shows a (4, 4) coordination polymer layer, but with pendant dpa ligands curling in through the grid apertures. {[Cd(cca)(4-bpmp)(H 2 O)]·2H 2 O} n ( 2 , 4-bpmp = bis(4-pyridylmethyl)piperazine) also has a 2-D coordination polymer layer structure, but with closely interdigitated (6, 3) herringbone motifs. [Cd(cca)(4-bpfp)] n ( 3 , 4-bpfp = bis(4-pyridylformyl)piperazine) manifests a {Cd 2 (OCO) 2 } dimer-based 6-connected pcu 3-D network. All three materials undergo modest to strong blue-violet fluorescence under ultraviolet radiation. Thermal decomposition behavior is also probed.
Effects of hydrocarbon enrichment on trichloroethylene biodegradation and microbial populations in finished compost

This study focused on the capacity of finished compost, often used as packing material in biofiltration units, to support microbial biodegradation of trichloroethylene (TCE). Finished compost was enriched with methane or propane (10% head space) to stimulate cometabolic biodegradation of gaseous TCE. Successful hydrocarbon enrichment, as indicated by rapid depletion of hydrocarbon gas and measurable growth of hydrocarbon-utilizing micro-organisms, occurred within a week. Within batch reactor flasks, approximately 75% of head space TCE (1-40 ppmv) was rapidly sorbed onto compost material. Up to 99% of the remaining head space TCE was removed via biodegradation in compost enriched with either hydrocarbon. Hydrocarbon enrichment with methane or propane corresponded to 10-fold increases in methanotrophic or propanotrophic populations, respectively. Based on growth assessment under different nutritional regimes, there appeared to be complex metabolic interactions within the microbial community in enriched compost. Five separate bacterial cultures were derived from the hydrocarbon-enriched compost and assayed for the ability to degrade TCE.
Congestive heart failure self-management among US veterans: The role of personal and professional advocates

Abstract Objective Understand patients’ experiences with primary care services for congestive heart failure (CHF) and explore the relationship between health services and self-management. Methods We conducted semi-structured interviews with thirty-nine patients with CHF receiving care at one Veterans Affairs Medical Center (VA). We analyzed data using thematic content analysis. Results Participants acknowledged the importance of ongoing engagement in the plan of care for CHF. They attributed success in this effort to be greatly influenced by personal advocates. The advocates included both members of the healthcare team with whom they had a continuity relationship and friends or family members who assisted on a daily basis. Participants also identified psychological symptoms as a major barrier to carrying out self-care. Conclusion Patients identify relationships with health care workers, help from family and friends, and mental health problems as major influences on the ability to manage their CHF. Practice implications Efforts to optimize CHF self-management should attend to health system and psychosocial barriers to care.
Evidence for a glutathionyl-enzyme intermediate in the amidase activity of the bifunctional glutathionylspermidine synthetase/amidase from Escherichia coli.

Glutathionylspermidine (Gsp) is a metabolite common to Escherichia coli and protozoal parasites of the Trypanosoma family. Though its role in E. coli is unknown, Gsp is known to be an intermediate in the biosynthesis of N1,N8-bis(glutathionyl)spermidine (trypanothione), a metabolite unique to trypanosomatids that may allow the parasites to overcome oxidative stresses induced by host defense mechanisms. The bifunctional Gsp-synthetase/amidase from E. coli catalyzes both amide bond formation and breakdown between the N1-amine of spermidine [N-(3-aminopropyl)-1,4-diaminobutane] and the glycine carboxylate of glutathione (γ-Glu-Cys-Gly), with net hydrolysis of ATP [Bollinger et al. (1995) J. Biol. Chem. 270 (23), 14031−14041]. Synthetase and amidase activities reside in separate domains of the protein, and liberation of the amidase domain from the synthetase domain activates the amidase activity as much as 70-fold in kcat/Km for a chromogenic substrate γ-Glu-Ala-Gly-pNA [Kwon et al., (1997) J. Biol. Chem. 272...
Oxidation of magnesiowustite single crystals-I. Optical and kinetic data

Abstract The oxidation of homogeneous magnesiowustite single crystals, prepared by diffusing iron into MgO single crystals, is studied optically and by X-ray diffraction. Crystals designated L (low), M (medium) and H (high), containing about 20, 36, and 67 cation per cent Fe were prepared. By control of temperature and oxygen partial pressure using appropriate CO/CO2 gas mixtures, the magnesiowustite crystals were equilibrated at or near their upper ferric iron composition, and then were oxidized to magnesioferrite in air at temperatures in the range 800–1100°C and for various periods of time. Photomicrographs showed that L and M crystals oxidized by forming magnesioferrite surface layers, with “fingers” of magnesioferrite extending into the crystals and with numerous small isolated “islands” of magnesioferrite within the crystals. The growth of the external oxidized layer was found to be linear with time and with an activation energy of about 30 kcal/mol. Photomicrographs of H crystals show major development of magnesioferrite on external surfaces, with small amounts of hematite on or near the original surface and also on some internal (111) planes. The growth of the external oxidized layer is proportional to (time) 1 2 , suggesting a diffusion controlled mechanism, and the activation energy is about 18 kcal/mol. Comparison is made with data for oxidation behavior of iron oxides.
Circular dichroism and viscometric studies on a basic protein from pig brain.

— A highly purified basic protein prepared from pig brain was studied by circular dichroism and viscometry. The circular dichroism spectrum of the protein in 50% (v/v) aqueous n-propanol showed two negative bands (at 217-220 nm and 204 nm); the spectrum in 90% (v/v) aqueous trifluoroethanol similarly showed two negative bands (at 217 nm and at 206 nm). The molar ellipticity of this protein in aqueous solvents was relatively flat and no negative bands were observed above 200 nm. The ηap C of the protein from pig brain was 0-12 as C O in tris buffer (0-1 M, pH 7-8). On the basis of these studies we concluded that the protein is asymmetric and extended in aqueous systems and contains a maximum of 20 per cent α-helix in trifluoroethanol.
Using new aggregation operators in rule-based intelligent control

A new aggregation operator is applied in the design of an approximate reasoning-based controller. The ordered weighted averaging (OWA) operator has the property of lying between the AND function and the OR function used in previous fuzzy set reasoning systems. It is shown that, by applying OWA operators, more generalized types of control rules, which may include linguistic quantifiers such as MANY and MOST, can be developed. The new aggregation operators, as tested in a cart-pole balancing control problem, illustrate improved performance when compared with existing fuzzy control aggregation schemes. >
A descriptive analysis of nontuberculous mycobacterial infections (NTM) of the upper extremity

Abstract Objectives Nontuberculous mycobacterial (NTM) infections are frequently reported as a cause of bone and soft-tissue infection of the upper extremity, primarily in the hand and wrist. Limited information exists on clinical characteristics and treatment outcomes of patients with NTM infection of the upper extremity. The clinical and radiological characteristic of these infections in a large group of patients with upper extremity NTM infections are described herein. Methods A retrospective analysis was conducted of NTM infections of the upper extremity at Mayo Clinic Florida from December 2000 through December 2012. Only patients with positive mycobacterial cultures from the upper extremities were included. Data collection included demographics, radiologic and clinical characteristics, mycobacterial culture results, time to diagnosis and treatment outcomes. Results Forty-two patients were included; 71% were male and the mean age was 60 ± 18 years. Eighteen (43%) patients were diagnosed with skin/soft tissue infections and 15 (36%) had tenosynovitis. Twenty-six (62%) patients were immunosuppressed. The most common underlying medical conditions were rheumatologic disorders (40%) and diabetes mellitus (17%). Sixteen (38%) patients were taking glucocorticosteroids, and 11 (26%) patients were receiving tumor necrosis factor alpha (TNF-α) inhibitors at the time of diagnosis. Injuries to the affected extremity were reported in 62% of patients. Fishing (21%) and gardening (14%) were the most common reported exposures. Signs and symptoms of infection were localized to the skin in 62% and extended to the joints in 52%. Mycobacterium marinum (36%) and Mycobacterium chelonae / abscessus (33%) were the two most commonly identified organisms. Radiologic studies were available in 30 (71%) patients. Average time to clinical evaluation from onset of symptoms was 2.6 (±3.5) months and time to diagnosis from initial clinical evaluation was 4.5 (±4.5) months. Forty-one (98%) patients were treated. Twenty-eight (68%) patients were treated with both antimicrobial and surgical debridement, nine (21%) with antimicrobial treatment alone, and four (10%) with surgical debridement alone. Twenty-six (62%) patients were cured, four (9%) relapsed after the first round of treatment, two (5%) failed all treatment modalities, and three (7%) patients died. Conclusion Diagnosis of NTM infection of the upper extremity is often delayed due to its indolent presentation and lack of clinical suspicion. Healthcare professionals should be aware of the increasing incidence of soft tissue NTM infection after percutaneous injury, especially in immunosuppressed patients, to improve diagnostic promptness and treatment outcome.