cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimal flux patterns in cellular metabolic networks.

The availability of whole-cell-level metabolic networks of high quality has made it possible to develop a predictive understanding of bacterial metabolism. Using the optimization framework of flux balance analysis, I investigate the metabolic response and activity patterns to variations in the availability of nutrient and chemical factors such as oxygen and ammonia by simulating 30 000 random cellular environments. The distribution of reaction fluxes is heavy tailed for the bacteria H. pylori and E. coli, and the eukaryote S. cerevisiae. While the majority of flux balance investigations has relied on implementations of the simplex method, it is necessary to use interior-point optimization algorithms to adequately characterize the full range of activity patterns on metabolic networks. The interior-point activity pattern is bimodal for E. coli and S. cerevisiae, suggesting that most metabolic reactions are either in frequent use or are rarely active. The trimodal activity pattern of H. pylori indicates that a group of its metabolic reactions (20%) are active in approximately half of the simulated environments. Constructing the high-flux backbone of the network for every environment, there is a clear trend that the more frequently a reaction is active, the more likely it is a part of the backbone. Finally, I briefly discuss the predicted activity patterns of the central carbon metabolic pathways for the sample of random environments.
Discounted stochastic games with strategic complementarities: theory and applications

This paper considers a general class of discounted Markov stochastic games characterized by multidimensional state and action spaces with an order structure, and one-period reward functions and state transition law satisfying some complementarity and monotonicity conditions. Existence of pure-strategy Markov (Markov-stationary) equilibria for the finite (infinite) horizon game, with nondecreasing -and possibly discontinuous - strategies and value functions, is proved. The analysis is based on lattice programming, and not on concavity assumptions. Selected economic applications that fit the underlying framework are described: dynamic search with learning, long-run competition with learning-by-doing or network effects, and resource extraction.
Fetal lung volume and quantification of liver herniation by magnetic resonance imaging in isolated congenital diaphragmatic hernia.

Objective To determine associations between fetal lung and liver herniation volumes measured by magnetic resonance imaging (MRI) and mortality/need for extracorporeal membrane oxygenation (ECMO) in cases of isolated congenital diaphragmatic hernia (CDH). A secondary objective was to compare prenatal MRI parameters with two-dimensional ultrasound lung measurements. Methods A retrospective review of medical records of all fetuses with isolated CDH evaluated between January 2004 and July 2012 was performed. The following MRI parameters were measured at 20–32 weeks: observed/expected total fetal lung volume (o/e-TLV), predicted pulmonary volume (PPV), percentage of liver herniated into the fetal thorax (%LH) and the liver/thoracic volume ratio (LiTR). These were compared with the ultrasound-determined lung-to-head ratio (LHR) and the observed/expected LHR (o/e-LHR) in the same cohort. The predictive value of MRI and ultrasound parameters for mortality and the need for ECMO was evaluated by univariate, multivariate and factor analysis and by receiver–operating characteristics curves. Results Eighty fetuses with isolated CDH were evaluated. Overall mortality was 18/80 (22.5%). Two newborns died a few hours after birth. ECMO was performed in 29/78 (37.2%) newborns, with a survival rate of 48.3% (14/29). The side of the diaphragmatic defect was not associated with mortality (P = 0.99) or the need for ECMO (P = 0.48). Good correlation was observed among o/e-TLV, PPV, LHR and o/e-LHR as well as between %LH and LiTR (r = 0.89; P 0.05). All parameters were statistically associated with mortality or the need for ECMO. The best combination of measurements to predict mortality was o/e-TLV and %LH, with 83% accuracy. Conclusion Mortality and the need for ECMO in neonates with isolated CDH can be best predicted using a combination of MRI o/e-TLV and %LH. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Modulation of skeletal muscle protein synthesis by amino acids and insulin during sepsis

Effects of different concentrations of insulin and amino acids on protein synthesis in skeletal muscle of young, fed septic rats were determined in the perfused rat hindlimb. Rates of protein synthesis in gastrocnemius were measured by incorporation of [3H-phenylalanine into protein. Perfusion of hindlimb muscles from young, fed control rats with medium containing either insulin and a complete mixture of amino acids at plasma concentration (1x) or a mixture of amino acids at 10-fold (10x) plasma concentration resulted in an approximately twofold stimulation of the rate of protein synthesis. The effect of amino acids on protein synthesis was partly accounted for by elevated concentrations of branched-chain amino acids ([BCAA] leucine, isoleucine, and valine). In young, fed septic rats, the rate of protein synthesis in muscle perfused with buffer containing the normal concentration of amino acids was reduced 40% as compared with control levels (P < .05). In contrast to controls, addition of insulin (1,000 μU/mL) did not augment protein synthesis in muscle from young, fed septic rats perfused with the complete mixture of amino acids. Addition of insulin 10,000 μU/mL stimulated protein synthesis approximately 80% in gastrocnemius of septic rats (P < .05). However, the rate of protein synthesis remained less than that observed in young, fed control rats at similar insulin concentrations. Perfusion with medium containing 10x plasma amino acids stimulated protein synthesis approximately fourfold in young, fed septic rats as compared with control animals. In contrast to controls, BCAA at 10x plasma concentration did not augment protein synthesis in young, fed septic rats. There were no significant differences in rates of protein synthesis between control and nonseptic-abscess rats in any of the conditions examined. The results suggest a relative resistance of protein synthesis to the stimulatory effects of insulin or BCAA in muscle from young, fed septic animals, whereas the response to total amino acid supplementation is unaffected by the septic process.
Crystal structure of 1-meth-oxy-2,2,2-tris-(pyrazol-1-yl)ethane.

The title compound, C12H14N6O, consists of three pyrazole rings bound via nitro­gen to the distal ethane carbon of meth­oxy ethane. The dihedral angles between the three pyrazole rings are 67.62 (14), 73.74 (14), and 78.92 (12)°. In the crystal, mol­ecules are linked by bifurcated C—H,H⋯N hydrogen bonds, forming double-stranded chains along [001]. The chains are linked via C—H⋯O hydrogen bonds, forming a three-dimensional framework structure. The crystal was refined as a perfect (0.5:0.5) inversion twin.
AT&T: “Apologies are not enough”

AT&T's long distance service interruption in New York on September 17, 1991 was a serious threat to its image. After some initial confusion, including an ill‐advised attempt to shift the blame to lower level workers, Richard Allen, Chairman of AT&T, placed a full page newspaper advertisement to restore its image. This essay critically analyzes that statement, extending previous work on image restoration discourse by Benoit, Gullifor, and Panici (1991). Three primary strategies were developed appropriately in the discourse: mortification, plans for correcting the problem, and bolstering.
A convenient micromethod for the estimation of mitochondrial cytochrome c

Abstract 1. 1. A simple method is described for the extraction and estimation of mitochondrial cytochrome c; the assay is based on differences in the Soret band of cytochrome c in acid and alkaline solutions. 2. 2. The millimolar absorption index for the acid/base shift at 392.5–409.0 nm is 200.4, as compared with 25.1 for the corresponding oxidation/reduction shift at long wavelengths (535–550 nm); the sensitivity of the present method is such that reliable estimates of cytochrome c can be obtained with mitochondria isolated from as little as 5 mg fresh weight of insect flight muscle. 3. 3. The ratio of cytochrome c to protein in mitochondria isolated from flight muscles of the tsetse fly (Glossina morsitans) is 0.95 μmoles/g and of the blowfly (Sarcophaga nodosa) 1.14 μmoles/g; in both species the ratio remains constant during adult life. 4. 4. The proportion of cytochromes c, c′, b and aa3 in mitochondria of the tsetse fly is 1.00:0.51:0.69:0.98 and of the blowfly 1.00:0.46:0.54:0.52.
Enacting national selves: Authenticity, adventure, and disaffection in the Portuguese Diaspora

Disparate and, at times, contradictory enactments of “Portugueseness” are explored in relation to debates whose scope is local, national, and transnational. The focus is on how the national self‐representations of Portuguese migrants in Europe resonate with the hegemonic definitions of belonging in Portugal, Germany, and the newly emerging “Europe,” and how the differing images structure inclusion and exclusion within these polities. Descriptions of three localized events are juxtaposed to reveal what is at stake in these arguments over how to “be Portuguese” and why particular “knowledges, images, and discourses are … authorized” (Bhabha 1994: 270).
Conventional Pulse Oximetry Can Give Spurious Data in a Neonatal Population at Risk for Retinopathy of Prematurity (ROP) |[dagger]| 1260

Tighter control of oxygen titration in “at risk” premature neonates might reduce the incidence of complications associated with retinopathy of prematurity (STOP-ROP). Pulse oximetry (SpO2) has been used as a reference in determining oxygenation. SpO2 is determined by comparing absorbance of light (red and infrared) at two wavelengths during pulsatile blood flow. Motion, perfusion, and ambient light overwhelm the ability of a conventional oximeter to continuously transduce accurate readings in “at risk” premature infants. The Masimo Signal Extraction Technology (SET) calculates a noise reference and uses adaptive filters to attenuate artifact and amplify relevant signals. This study compares the Masimo SET to a conventional pulse oximeter (Nellcor) on ten sick newborns at risk for ROP. The Masimo sensor (LNOP Neo Pt) was attached to a Masimo prototype oximeter and the Nellcor sensor (N-25) to a Nellcor N-200 oximeter. Neonates were monitored for 3-4 hours with a sensor on each foot, then sensors were switched to the opposite foot and similarly monitored. ECG was interfaced from a SpaceLabs monitor to distinguish false oximeter events. Intrinsic motion, caregiver, and parental influenced desaturation were noted. The Masimo SET waveform was examined via a frequency analysis plot of SpO2. “True” desaturation occurred when a peak corresponding to the ECG frequency domain was identified and multiples of the waveform corroborated the finding (Comp. Biol. Med. 26:143-159, 1996). The total duration of Nellcor false alarms was nearly 14 times greater than Masimo SET. On average, the Nellcor alarmed falsely every 13.9min for 36.6s; Masimo SET, every 87.8min for 16.9s. False titration of oxygen may produce significant morbidity in the premature infant. A survey of >100 NICU's reported that the majority set high SpO2 alarms which “could predispose an infant on supplemental oxygen to hyperoxemia”(J. Perinatol. 17:341-5, 1997). The caregiver is numbed to a true alarm condition. Because of the high alarm rate, studies based upon a caregivers response to conventional oximetry are suspect at best. Table
Stacked Inspiratory Spirometry Reduces Pulmonary Shunt in Patients After Coronary Artery Bypass

Atelectasis is a major factor in postoperative morbidity for patients undergoing cardiopulmonary surgery. We evaluated the effectiveness of stacked inspiratory spirometry (STIS) in 17 patients status postcoronary artery bypass graft in a nonrandomized fashion. We measured pulmonary shunt as an endpoint, and compared the magnitudes before and after the STIS maneuver. Our results showed an 8.66 percent reduction in pulmonary shunt (p
Cheminformatics Analysis of Assertions Mined from Literature that Describe Drug-Induced Liver Injury in Different Species

Drug-induced liver injury is one of the main causes of drug attrition. The ability to predict the liver effects of drug candidates from their chemical structures is critical to help guide experimental drug discovery projects toward safer medicines. In this study, we have compiled a data set of 951 compounds reported to produce a wide range of effects in the liver in different species, comprising humans, rodents, and nonrodents. The liver effects for this data set were obtained as assertional metadata, generated from MEDLINE abstracts using a unique combination of lexical and linguistic methods and ontological rules. We have analyzed this data set using conventional cheminformatics approaches and addressed several questions pertaining to cross-species concordance of liver effects, chemical determinants of liver effects in humans, and the prediction of whether a given compound is likely to cause a liver effect in humans. We found that the concordance of liver effects was relatively low (ca. 39−44%) between ...
Determination of primary motoneuron identity in developing zebrafish embryos

The developmental determination of primary motoneurons was investigated by transplanting identified motoneurons in embryonic zebrafish to new spinal cord positions. Some cells moved from the new positions in which they were placed back to their original positions, thus it was difficult to evaluate whether they were determined. Among cells that remained in their new positions, those transplanted about 1 hour before axogenesis developed axonal trajectories that were appropriate for their original soma positions, whereas those transplanted 2 to 3 hours before axogenesis developed morphologies appropriate for their new soma positions. These results suggest that motoneuronal identity is determined before axogenesis.
Some design criteria in scanning tunneling microscopy

Optimum functioning of a scanning tunneling microscope (STM) requires tip-to-sample position control with picometer precision, a rough and fine positioning capability in three dimensions, a scanning range of at least 100 times the lateral resolution, a scanning speed as high as possible, and also, preferably, simplicity of operation. These requirements have to be satisfied in the presence of building vibrations with up to micrometer-size amplitudes, temperature drift, and other perturbations. They result in design rules, presented and discussed here, for the optimization of damping, stiffness, electrical control circuitry, and the performance of the piezoelectric actuators usually employed in STMs.
Relationship between ribosomal activity and age of culture in Escherichia coli B.

Abstract Ribosomal fractions prepared from Escherichia coli cells taken from cultures in the early log phase of growth are more active forming polyphenylalanine directed by polyuridylic acid than similar fractions obtained from cells only a few hours later. Ribosomal preparations from young cultures are also more sensitive to the action of streptomycin. These effects are due in a large part to the relative preponderance of free ribosomes in the preparations from the younger cultures.
A Direct Time-Domain FDTD Near-Field-to-Far-Field Transform in the Presence of an Infinite Grounded Dielectric Slab

A direct time-domain near-field-to-far-field transform (NFFFT) is developed that is applicable to the finite-difference time-domain analysis of radiation in the presence of a non-dispersive, infinite, grounded dielectric slab. With minor modification and/or simplification, the results can also be applied to the dielectric half-space and the infinite ungrounded dielectric slab. A few time-domain radiation examples involving microstrip transmission lines are used to illustrate the method
Matrix metalloproteinases and angiogenesis

Matrix metalloproteinases (MMPs) are a family of enzymes that proteolytically degrade various components of the extracellular matrix (ECM). Angiogenesis is the process of forming new blood vessels from existing ones and requires degradation of the vascular basement membrane and remodeling of the ECM in order to allow endothelial cells to migrate and invade into the surrounding tissue. MMPs participate in this remodeling of basement membranes and ECM. However, it has become clear that MMPs contribute more to angiogenesis than just degrading ECM components. Specific MMPs have been shown to enhance angiogenesis by helping to detach pericytes from vessels undergoing angiogenesis, by releasing ECM-bound angiogenic growth factors, by exposing cryptic proangiogenic integrin binding sites in the ECM, by generating promigratory ECM component fragments, and by cleaving endothelial cell-cell adhesions. MMPs can also contribute negatively to angiogenesis through the generation of endogenous angiogenesis inhibitors by proteolytic cleavage of certain collagen chains and plasminogen and by modulating cell receptor signaling by cleaving off their ligand-binding domains. A number of inhibitors of MMPs that show antiangiogenic activity are already in early stages of clinical trials, primarily to treat cancer and cancer-associated angiogenesis. However, because of the multiple effects of MMPs on angiogenesis, careful testing of these MMP inhibitors is necessary to show that these compounds do not actually enhance angiogenesis.
Copper ligation to soluble oligomers of the English mutant of the amyloid-β peptide yields a linear Cu(I) site that is resistant to O2 oxidation

Copper coordination to soluble oligomers of the English (AβH(6)R) mutant of the amyloid-β peptide is probed. Cu(II) coordination yields a square planar (N/O)4 coordination environment, while reduction yields an O2 inert linear bis-His Cu(I) centre.
Dynamic integrated system optimization and parameter estimation for discrete time optimal control of nonlinear systems

An algorithm for solving nonlinear discrete time optimal control problems with model-reality differences is presented. The technique uses Dynamic Integrated System Optimization and Parameter Estimation (DISOPE), which achieves the correct optimal solution in spite of deficiencies in the mathematical model employed in the optimization procedure. A version of the algorithm with a linear-quadratic model-based problem, implemented in the C+ + programming language, is developed and applied to illustrative simulation examples. An analysis of the optimality and convergence properties of the algorithm is also presented.
Hypertension in obstructive sleep apnea: risk and therapy

Obstructive sleep apnea (OSA) is a common form of sleep-disordered breathing that occurs due to recurrent collapse of the upper airway with inspiration. Large epidemiologic studies have established that OSA is a risk factor for developing hypertension. The pathophysiologic mechanism of this relationship is due to the distinctive pattern of intermittent hypoxia seen in OSA. This pattern increases sympathetic tone, oxidative stress, inflammation and endothelial dysfunction. These processes can all lead to persistent elevation of blood pressure beyond the obstructive events. OSA should be considered as part of the workup of patients with hypertension. Treatment of OSA with continuous positive airway pressure has an effect on hypertension control and risk reduction of cardiovascular diseases. This review discusses the pathophysiology and causal relationship between OSA and hypertension, along with the cardiovascular effects of treatment of OSA.
Monocyte Chemotactic and Activating factor is a potent Histamine-releasing Factor for human basophils.

Recombinant monocyte chemotactic-activating factor (MCAF) has been shown to induce histamine release from human basophils with a dose response between 10(-9) and 10(-6) M. The peak of activity was reached at 10(-7) M. Histamine release by MCAF was rapid with an initial rate comparable with histamine release by an optimal dose of anti-IgE. MCAF led to peak histamine release within 1 min. 80% of the subjects tested were responsive to MCAF or anti-IgE, while all were responsive to FMLP. The percentage histamine release by MCAF was, however, less than that seen with anti-IgE or FMLP, but this was attributable to a lesser percent release in nonatopic subjects; atopic subjects responded similarly to all three agonists. MCAF was also shown to activate highly purified human basophils more readily than mixed leukocytes, and its activity was inhibited by a polyclonal rabbit antibody. At a suboptimal concentration (2.5 x 10(-9) M), MCAF was unable to prime the basophil to histamine release by other secretagogues. However, interleukin 3 (IL-3) and IL-5 could each prime basophils for MCAF-induced secretion. Therefore, our results suggest that MCAF may be a major contributor to the histamine-releasing activity seen in peripheral blood mononuclear cell supernatants that has been designated histamine releasing factor(s).
Physicochemical Changes in Prawns (Machrobrachium rosenbergii) Subjected to Multiple Freeze‐Thaw Cycles

Fresh prawns were subjected to five freeze-thaw cycles (–29°C ⇄ 22°C) and associated physicochemical changes in muscle were determined. Shear force to break prawn tails was dependent on prawn size, more on weight (r = 0.75–0.81) than on diameter (r = 0.56–0.66). No change (P > 0.05) in shear force was observed in raw prawns after five freeze-thaw cycles. However, shear force of cooked prawns decreased after three freeze-thaw cycles which coincided with accelerated lipid oxidation in raw prawns. Electrophoretic analysis revealed gradual decreases in myosin, actin, and most other myofibrillar proteins with each successive freeze-thaw cycle. Enthalpy of protein denaturation decreased from 16.6 J/g (fresh) to 13.5 J/g after one freeze-thaw cycle with minor changes thereafter.
Mouse β-Defensin 1 Is a Salt-Sensitive Antimicrobial Peptide Present in Epithelia of the Lung and Urogenital Tract

One component of host defense at mucosal surfaces appears to be epithelium-derived peptides with antimicrobial activity called defensins. Human β-defensin 1 (hBD-1) represents the first member of the β-defensin family isolated from humans and has been implicated in the pathogenesis of cystic fibrosis. We describe in this report the isolation and characterization of a murine homolog of hBD-1 called mouse β-defensin 1 (mBD-1). The predicted amino acid sequence shows the hallmark features of other known epithelial β-defensins, including the ordered array of six cysteine residues. Analysis of a genomic clone of mBD-1 revealed two exons separated by a 15-kb intron. By use of fluorescence in situ hybridization, the mBD-1 gene was localized at the proximal portion of chromosome 8, the site where mouse α-defensins are found. Lysates from cells transfected with the mBD-1 cDNA showed antibacterial activity against gram-positive and gram-negative bacteria. mBD-1 transcripts were found in kidney, liver, and female reproductive organ tissues. In the airways, mBD-1 is expressed diffusely throughout the epithelial cells of the large proximal airways with less expression in the small distal airways and no expression in alveolar cells. The present study demonstrates that a β-defensin potentially homologous to human β-defensin 1 is present in the respiratory system and other mucosal surfaces in mice.
The hybrid open-framework of tin(II) phosphonopropionate oxalate, Sn4(O3PCH2CH2CO2)2(C2O4)

The hydrothermal synthesis and single crystal XRD characterization of a three-dimensional open-framework tin(II) phosphonopropionate oxalate, Sn4(O3PCH2CH2CO2) 2- (C2O4), is described; the structure contains two different bifunctional linkers as well as SnO3 and SnO4 polyhedra each with a stereochemically active lone pair of electrons, and exhibits several types of channels.
Who speaks “broken English”? US undergraduates’ perceptions of non‐native English1

This study attempts to discover how native US English speakers construct social categories for people outside the US. A close look at one group's belief system provides insights that can be used in addressing linguistic discrimination, with information on how varieties and features of varieties are perceived. Here 79 US undergraduates labeled maps with descriptions of English spoken by international students, and 208 rated the English of students from 58 countries. Familiarity and socio-political relationships with countries of origin appeared to play a role in responses. Evaluation was often central to description, with a category of stigmatized, often “broken”, English used for all non-native speakers except perhaps (Western) Europeans. Salient subgroups were: negatively evaluated “Chinese” English, somewhat negatively evaluated “Mexican” English, and “harsh” and “guttural” Russian English. Respondents had competing frameworks for classifying Indian and German English. A model of these overlapping categories and implications for addressing linguistic prejudice are suggested.
Career Education in the Primary Grades: Building Work-Readiness Through an Experiential Curriculum

(2000). Career Education in the Primary Grades: Building Work-Readiness Through an Experiential Curriculum. Childhood Education: Vol. 76, No. 4, pp. 219-224.
Network flow algorithms for wireless networks and design and analysis of rate compatible ldpc codes

While Shannon already characterized the capacity of point-to-point channels back in 1948, characterizing the capacity of wireless networks has been a challenging problem. The deterministic channel model proposed by Avestimehr, etc. (2007 - 1) has been a promising approach for approximating the Gaussian channel capacity and has been widely studied recently. Motivated by this model, an improved combinatorial algorithm is considered for finding the unicast capacity for wireless information flow on such deterministic networks in the first part of this thesis. Our algorithm fully explores the useful combinatorial features intrinsic in the problem. Our improvement applies generally with any size of finite fields associated with the channel model. Comparing with other related algorithms, our improved algorithm has very competitive performance in complexity. In the second part of our work, we consider the design and analysis of rate-compatible LDPC codes. Rate-compatible LDPC codes are basically a family of nested codes, operating at different code rates and all of them can be encoded and decoded using a single encoder and decoder pair. Those properties make rate-compatible LDPC codes a good choice for changing channel conditions, like in wireless communications. The previous work on the design and analysis of LDPC codes are all targeting at a specific code rate and no work is known on the design and analysis of rate-compatible LDPC codes so that the code performance at all code rates in the family is manageable and predictable. In our work, we proposed algorithms for the design and analysis of rate-compatible LDPC codes with good performance and make the code performance at all code rates manageable and predictable. Our work is based on E2RC codes, while our approaches in the design and analysis can be applied more generally not only to E2RC codes, but to other suitable scenarios, like the design of IRA codes. Most encouragingly, we obtain families of rate-compatible codes whose gaps to capacity are at most 0.3 dB across the range of rates when the maximum variable node degree is twenty, which is very promising compared with other existing results.
Top predators provide insurance against climate change

Recent research by Wilmers et al. shows that top predators might buffer some of the ecological effects of climate change. Top predators can regulate the structure of entire communities and dampen their variability; however, in their absence, prey populations are likely to fluctuate greatly owing to bottom-up factors. Restoring top predators to their natural environment could provide insurance against undesired effects of climate change on ecological communities.
Many-body fits of phase-equivalent effective interactions

In many-body theory, it is often useful to renormalize short-distance, high-momentum components of an interaction via unitary transformations. Such transformations preserve the on-shell physical observables of the two-body system (mostly phase shifts, hence unitarily connected effective interactions are often called phase equivalent) while modifying off-shell T-matrix elements influential in many-body systems. In this paper, I lay out a general and systematic approach for controlling the off-shell behavior of an effective interaction, which can be adjusted to many-body properties, and present an application to trapped fermions at the unitary limit.
RAPD analysis of genetic variation among propanil-resistant and -susceptible Echinochloa crus-galli populations in Arkansas

Abstract The extensive use of propanil for weed control in Oryza sativa over the past 30 yr has led to the development of propanil-resistant Echinochloa crus-galli. This problem was first identified in one Arkansas county in 1990. Since that time, 171 resistant populations have been identified in 20 counties. Random amplified polymorphic DNA (RAPD) analysis was used to assess genetic variation among populations of propanil-resistant and -susceptible E. crus-galli in Arkansas and to elucidate the origin of resistance and its dispersal. Sixteen E. crus-galli populations from seven Arkansas counties and one population from Mississippi were analyzed using 13 primers, which amplified a total of 159 repeatable fragments. Genetic distance was calculated among the populations, and the populations were clustered. The analysis revealed two distinct clusters with an average between-cluster genetic distance of 0.436 and average within-cluster distances of 0.012 and 0.029. These clusters may represent different Echino...
Oxidative Deamination of N-Acetyl Neuraminic Acid: Substituent Effects and Mechanism.

A study of the mechanism of the oxidative deamination of the N-nitroso-N-acetyl sialyl glycosides leading with overall retention of configuration to the corresponding 2-keto-3-deoxy-d-glycero-d-galacto-nonulopyranosidonic acid (KDN) glycosides is described, making use of a series of differentially O-protected N-nitroso-N-acetyl sialyl glycosides and of isotopic labeling studies. No evidence is found for stereodirecting participation by ester groups at the 4- and 7-positions. Comparisons are drawn with oxidative deamination reactions of 4-amino-4-deoxy and 2-amino-2-deoxy hexopyranosides and a common mechanism is formulated involving the intermediacy of 1-oxabicyclo[3.1.0]hexyl oxonium ions following participation by the pyranoside ring oxygen. A minor reaction pathway has been uncovered by labeling studies in the β-thiosialosides that results in the exchange of the 4-O-acetyl group by the glacial acetic acid that serves as external nucleophile in the general oxidative deamination process. A mechanism is p...
Local semantic closure

Dans son traite de semantique formelle, Tarski a envisage la possibilite d'appliquer sa theorie de la verite aux langues naturelles en elaborant une hierarchie des langues. Dans cet article, l'A. montre comment cette hierarchie des langues peut etre representee dans le cadre de la grammaire localement standard, qui considere chaque langue naturelle comme une structure ressemblant a un collecteur dans lequel chaque phrase declarative fait partie d'un ensemble de phrases, appele voisinage standard qui est associe a une algebre de formules dont la structure est celle de la logique standard des predicats du premier ordre. La these fondamentale de la theorie de la grammaire localement standard stipule que la langue anglaise peut etre couverte par des voisinages standards et qu'elle possede la propriete de cloture semantique locale, dans la mesure ou chaque phrase anglaise (au mode declaratif) est contenue dans un voisinage standard emboite dans une hierarchie semantique locale
Secure and robust symmetric key generation using physical layer techniques under various wireless environments

Due to the unavoidable shared nature of the wireless radio spectrum, providing security for wireless communications presents unique challenges. Cryptographic keys have been used as a primary technique for securing wireless networks but are not completely secure. The symmetric keys used for cryptographic purposes are vulnerable to man-in-the-middle and brute force attacks. More recently, PHY-layer based techniques have gained significant attention, where the principle of channel reciprocity and the natural randomness of the measured wireless channel to generate secret keys is leveraged. Although, PHY-layer secret key generation has been investigated and presented in the literature before, there has been a lack of discussion in terms of obtaining symmetric keys on both ends of the link. In this work, we present a novel PHY-layer secret key generation technique that aims for symmetric encryption keys while limiting the information leaked to an eavesdropper to ensure complete secrecy and to prevent potential intelligent attacks. Our algorithm utilizes forward and backward channel state information in a given wireless link and combats the minute differences observed in these pairs by generating channel trend information. We demonstrate our technique using experimental results from a realtime SDR testbed connected to a wireless channel emulator. Our results indicate that the algorithm is successful in generating symmetric keys under various wireless environments without revealing any information pertaining to the key via the open wireless channel. Our secret key extraction rate can reach values in excess of 17.3 Kbps.
Clinical Embryology of the Abdomen

Conventional distinction between intraperitoneal and extraperitoneal sites is often helpful in differential diagnostic considerations. Yet it should be understood that the abdomen and pelvis constitute an anatomic continuum that is punctuated by the mesenteries, ligaments, and fasciae, which may either confine pathology or actually provide avenues for disease spread.
Vascular Surgery in North America: Current Perspectives in Peripheral Arterial Disease

Over the course of the past several decades treatment of peripheral arterial disease (PAD) has changed in North America. Advent of new technology has led to a shift in the initial treatment of both intermittent claudication (IC) and critical limb ischemia (CLI) towards endovascular intervention—including percutaneous balloon angioplasty, stenting and atherectomy. Overall increase in interventions for PAD correlates with a surge in the number of endovascular procedures performed by interventional cardiologists, interventional radiologists and vascular surgeons. Changes in reimbursement patterns has led to a trend towards these procedures being performed in an outpatient or office setting. Although this has resulted in fewer cases being performed in the hospital potential cost saving has been offset by increased use of the more highly reimbursed atherectomy in the outpatient setting. With regard to recommendations on how to treat these patients the Society of Vascular Surgery (SVS) has recently published guidelines for the treatment of IC emphasizing the importance of initial conservative medical management. There continues to be significant equipoise in the treatment of CLI across North America leading to tremendous variability in the use of open surgery and endovascular therapy. Guidance for the future treatment of CLI is partially dependent upon the Best Endovascular versus Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial, a randomized, controlled trial currently accruing patients in North America.
Symptom reports in severe chronic insomnia.

Study objectives To describe patterns and severities of the daytime and nighttime symptoms of chronic insomnia patients. Design Exploratory chart review from clinicians' evaluation summaries, a self-report screening instrument, the Pittsburgh Sleep Quality Index, the Beck Depression Inventory, the Epworth Sleepiness Scale, and the Hopkins Symptom Checklist-90 (HSCL90). Setting A regional sleep disorders referral clinic. Patients or participants 94 patients with chronic insomnia (DSM-IV code 307.42), classified into the subgroups "Primary Insomnia," "Depression-Related," "Anxiety-Related," and "Other". Interventions N/A. Measurements and results Frequent symptoms occurred not only in nocturnal domains (e.g., sleep disturbances, environmental sensitivity), but also in daytime domains (e.g., cognitive difficulties, sleepiness). Compared to primary insomnia patients, those with depression-related insomnia endorsed more severe symptoms. All subgroups endorsed a generally similar symptom profile when single symptoms were considered in isolation. When considered conjointly, severe symptoms typical of depression and generalized social alienation had a high negative predictive value for primary insomnia. The number of severe symptoms on the HSCL90 was related to fewer sleep hours in the nonprimary insomnia subgroup but not in the primary insomnia subgroup. Conclusions Patients with chronic insomnia report significant daytime as well as nighttime symptoms. Depression-related and primary insomnias were separable only by some highly characteristic symptoms of depression. Diagnostic subgroups of insomnia patients may vary in how their overall distress relates to diminished self-reported sleep. Nighttime and daytime symptoms need to be assessed together when measuring insomnia severity.
Acceleration waves on random fields with fractal and Hurst effects

Abstract In this study, we determine the effect of spatial randomness on the probability of shock formulation and the distance to form shocks from acceleration waves as a function of the initial amplitude. The noise is applied to the dissipation and elastic nonlinearity of the system for two different cases: (i) two variables with the same noise of varying intensity and (ii) four variables with the same noise of varying intensity. The random fields used here are unique as they can capture and decouple the field’s fractal dimension and Hurst parameter. We focus on determining the driving parameter, either fractal or Hurst, which is significant in altering the response of the system.
Angiotensin II for the Treatment of Vasodilatory Shock — Promise and Caution

Shock is one of the most common reasons for admission of patients to an intensive care unit. Low blood pressure is a hallmark of shock, and raising blood pressure is one of the foremost therapeutic goals in this setting. In patients with vasodilatory (i.e., “distributive”) shock, who represent approximately two thirds of all patients with shock,1 the usual method of raising blood pressure after fluid resuscitation is intravenous infusion of a vasopressor agent. The agents most commonly used to raise blood pressure in patients with vasodilatory shock are the adrenergic agents norepinephrine (recommended first-line therapy) and epinephrine — both of . . .
Methods and Considerations for Dynamic Analysis of Functional MR Imaging Data

Functional MR imaging (fMR imaging) studies have recently begun to examine spontaneous changes in interregional interactions (functional connectivity) over seconds to minutes, and their relation to natural shifts in cognitive and physiologic states. This practice opens the potential for uncovering structured, transient configurations of coordinated brain activity whose features may provide novel cognitive and clinical biomarkers. However, analysis of these time-varying phenomena requires careful differentiation between neural and nonneural contributions to the fMR imaging signal and thorough validation and statistical testing. In this article, the authors present an overview of methodological and interpretational considerations in this emerging field.
Fatigue Behaviour of Structural Ceramics

4-point bending static and cyclic fatigue tests are carried out on several structural ceramics both at room and elevated temperatures. Measured fatigue behaviours are compared with the lifetime predicted from the dynamic fatigue properties and cyclic loading effects on delayed failure are discussed. Experimental results indicate that a delayed failure of ceramics under a cyclic loading is caused mainly by extension of a pre-existed flaw and the lifetime is substantially predictable from a subcritical crack growth behaviour estimated under a static or quasi-static loading condition. It is also pointed out that at elevated temperatures the crystallization of glassy phase at grain boundaries extends the lifetime and that a crack growth is accelerated by compressive stress if grain (cluster) bridgings and/or crack interlockings are formed on a crack surface. Humidity controlled stress corrosion of a glassy phase at grain boundaries and mechanical fracture through the grain boundaries due to softening of the glassy phase are considered as main crack growth mechanisms at room and elevated temperatures, respectively. From these results it is concluded that the fatigue behaviour of ceramics is strongly affected by the properties of grain boundaries.
Associate Program Directors in Surgery: A Select Group of Surgical Educators

Objective The role of the Associate Program Director (APD) within surgical education is not clearly defined or regulated by the Accreditation Council for Graduate Medical Education, often leading to variations in the responsibilities among institutions. Required credentials are not specified and compensation and protected time are not regulated resulting in large discrepancies among institutions. APDs are brought into the fold of surgical education to parcel out the escalating responsibilities of program director (PD). The Association of Program Directors in Surgery, Associate Program Directors Committee sent a survey to all APDs to better understand the role of the APDs within the hierarchy of surgical education. Design A survey was sent to all 235 general surgery residency programs through the Association of Program Directors in Surgery list serve. The survey collected information on APD demographics, characteristics, and program information, qualifications of the APD, time commitment and compensation, administrative duties, and projected career track. Setting General surgery residency programs within the United States. Participants 108 Associate Program Directors in general surgery Results A total of 108 (46%) APDs responded to the survey. Seventy-three (70.2%) of the APD’s were males. Most (77.8%) were in practice for more than 5 years, and 69% were at a university-based program. Most of the respondents felt that the administrative and curricular tasks were appropriately distributed between the APD and PD and many shared tasks with the PD. A total of 44.6% were on the path to become a future PD at their institution. An equal number of APDs (42.6%) were compensated above their base salary for being an APD vs no compensation at all; however, 16 (14.8%) had a reduced clinical load as part of their compensation for being an APD. Conclusion This is the first study to describe the characteristics of APDs within the hierarchy of surgical education. Our data demonstrate that APDs have a substantial role in the function of a residency program and they need to be developed to better define their position in the program leadership.
Genetic Variation, Magnesium Sulfate Exposure, and Adverse Neurodevelopmental Outcomes Following Preterm Birth.

Objective To evaluate the association of magnesium sulfate (MgSO 4 ) exposure and candidate gene polymorphisms with adverse neurodevelopmental outcomes following preterm birth. Study Design We performed a nested case–control analysis of a randomized trial of maternal MgSO 4 before anticipated preterm birth for the prevention of cerebral palsy (CP). Cases were children who died within 1 year of life or were survivors with abnormal neurodevelopment at age 2 years. Controls were race- and sex-matched survivors with normal neurodevelopment. We analyzed 45 candidate gene polymorphisms in inflammation, coagulation, and vascular regulation pathways and their association with (1) psychomotor delay, (2) mental delay, (3) CP, and (4) combined outcome of death/CP. Logistic regression analyses, conditional on maternal race and child sex, and adjusted for treatment group, gestational age at birth and maternal education, were performed. Results Four hundred and six subjects, 211 cases and 195 controls, were analyzed. The strongest association was for IL6R (rs 4601580) in which each additional copy of the minor allele was associated with an increased risk of psychomotor delay (adjusted odds ratio 3.3; 95% confidence interval, 1.7–6.5; p Conclusion Candidate gene polymorphisms are associated with death and adverse neurodevelopmental outcomes following preterm birth. MgSO 4 may abrogate this genotype association for some loci.
Effects in Adherent Subjects

Dropouts confound the treatment effect when the outcome and the dropout process both depend on subject characteristics. If dropout is unrelated to treatment, there is an unconfounded effect, but it...
Relationship of plaques and tangles to Alzheimer's disease phenotype

Publisher Summary This chapter discusses relationship of plaques and tangles to Alzheimer's disease (AD) phenotype. The clinical features of AD are pleiomorphic and in the early stages overlap the changes associated with normal aging. The probability that dementia is caused by AD then is determined by the exclusion of other known causes of dementia and by the degree to which the clinical presentation and course are characteristic of known cases of AD. Executive functioning, or the ability to inhibit inappropriate responses and select key information and behaviors for action often is affected early in dementia of the Alzheimer's type (DAT), and results in poor judgments and problem solving. There is increasing support for the possibility that phenotypic variants of DAT reflect different aetiologies that share a final common pathway of cerebral degeneration that in turn produces the general clinical features of gradually progressive impairment of memory and other cognitive functions. It is found that correlations between neocortical tangle densities and clinical measures of dementia severity are greater than for neocortical plaques and dementia severity. The neuronal counts, synaptic densities, and vascular amyloid burden have also been analyzed for associations with clinical status in AD.
Biogenesis and Degradation of Gap Junctions

The dynamic regulation of gap junction biogenesis and degradation is a key element in the control of intercellular communication. This regulation starts in the endoplasmic reticulum, in which a large fraction of newly synthesized connexin molecules can be degraded. Multisubunit assembly of endogenously expressed connexins is first detected in the trans-Golgi network, as opposed to the endoplasmic reticulum wherein most other integral membrane proteins oligomerize. Gap junction plaques grow, at least in part, by lateral diffusion of plasma membrane connexin hemichannels to the periphery of the plaques. Connexins have a half-life of a few hours, being turned over within the endoplasmic reticulum by the ubiquitin/proteasome system and after transport to the cell surface via the lysosome. Although some aspects of gap junction biogenesis and degradation are relatively well understood, several intriguing unanswered questions remain.
The Imperative to Enhance Heat Transfer

This review considers the many techniques that have been developed to enhance convective heat transfer. There is the desire to encourage or accommodate high heat fluxes. After introducing the techniques, the applications to the various modes of heat transfer (single-phase free convection, single-phase forced convection [including performance evaluation criteria, active techniques, and compound techniques], pool boiling, convective boiling/evaporation, vapor-space condensation, and convective condensation) are described. Comments are offered regarding the generations of heat transfer technology; advanced enhancement represents 3rd generation heat transfer technology.