cssi/SciSciGPT-SciSciNet huggingface dataset:
Contribution of competition for light to within-species variability in stomatal conductance

[1] Sap flux (JS) measurements were collected across two stands dominated by either trembling aspen or sugar maple in northern Wisconsin. Observed canopy transpiration (EC-obs) values derived from JS were used to parameterize the Terrestrial Regional Ecosystem Exchange Simulator ecosystem model. Modeled values of stomatal conductance (GS) were used to determine reference stomatal conductance (GSref), a proxy for GS that removes the effects of temporal responses to vapor pressure deficit (D) on spatial patterns of GS. Values of GSref were compared to observations of soil moisture, several physiological variables, and a competition index (CI) derived from a stand inventory, to determine the underlying cause of observed variability. Considerable variability in GSref between individual trees was found, with values ranging from 20 to 200 mmol m−2 s−1 and 20 to 100 mmol m−2 s−1 at the aspen and maple stands, respectively. Model-derived values of GSref and a sensitivity to D parameter (m) showed good agreement with a known empirical relationship for both stands. At both sites, GSref did not vary with topographic position, as indicated by surface soil moisture. No relationships were observed between GSref and tree height (HT), and a weak correlation with sapwood area (AS) was only significant for aspen. Significant nonlinear inverse relationships between GSref and CI were observed at both stands. Simulations with uniform reductions in incident photosynthetically active radiation (Q0) resulted in better agreement between observed and simulated EC. Our results suggest a link between photosynthesis and plant hydraulics whereby individual trees subject to photosynthetic limitation as a result of competitive shading exhibit a dynamic stomatal response resulting in a more conservative strategy for managing hydrologic resources.
Modeling the Transverse Thermal Conductivity of 2-D SiCf/SiC Composites Made with Woven Fabric

The hierarchical two-layer (H2L) model describes the effective transverse thermal conductivity (k{sub eff}) of a two-dimensional (2-D) SiC{sub f} /SiC composite plate made from stacked and infiltrated woven fabric layers in terms of constituent properties and microstructural and architectural variables. The H2L model includes the effects of fiber-matrix interfacial conductance, high-fiber packing fractions within individual tows, and the nonuniform nature of 2-D fabric/matrix layers that usually include a significant amount of interlayer porosity. Previously, H2L model k{sub eff} predictions were compared to measured values for two versions of 2-D Hi-Nicalon{sup TM}/pyrocarbon (PyC)/isothermal chemical vapor infiltration (ICVI)-SiC composite, one with a 'thin' (0.11-{mu}m) and the other with a 'thick' (1.04-{mu}m) PyC fiber coating, and for a 2-D Tyranno{sup TM} SA/thin PyC/forced flow chemical vapor infiltration SiC composite. In this study, H2L model k{sub eff} predictions were compared to measured values for a 2-D SiC{sub f} /SiC composite made using the ICVI process with Hi-Nicalon type S fabric and a thin PyC fiber coating. The values of k{sub eff} determined for the latter composite were significantly greater than the k{sub eff} values determined for the composites made with either the Hi-Nicalon or the Tyranno SA fabrics. Differences in k{sub eff} values weremore » expected for the different fiber types, but major differences also were due to observed microstructural and architectural variations between the composite systems, and as predicted by the H2L model.« less
“We Need to Have a Meeting”: Public Housing Demolition and Collective Agency in Atlanta, Georgia

The last two decades have witnessed widespread demolition of public housing and a large-scale relocation of public housing residents. Much of the current literature has examined the impact of demolition on relocated residents, focusing primarily on individual outcomes such as employment, housing quality, and health. This article examines the potential collective consequences of relocation by using data from 40 in-depth interviews conducted with relocated public housing residents in Atlanta, Georgia, to examine experiences of civic engagement and tenant activism before and after relocation. Participants describe frequent experiences of civic engagement and tenant activism in their public housing communities prior to demolition and also discuss how these collective actions often translated into meaningful gains for their communities. Participants also describe challenges associated with reestablishing these sources of collective agency in their new, post demolition, private-market rental communities where o...
A Zeolitic Structure (ITQ-34) with Connected 9- and 10-Ring Channels Obtained with Phosphonium Cations as Structure Directing Agents

Zeolites are materials with a large applied interest. Here we present ITQ-34 a new zeolitic material, obtained combining the use of the highly stable tetraalkylphosphonium cations as structure directing agents with the incorporation of Ge atoms in the structure.
Protection of Mice against Lethal Staphylococcus Infection by Escherichia coli O86 Fractions.

Small doses of protein-lipopolysaccharides and lipopolysaccharides from Escherichia coli O86 prevent the death of mice infected intraperitoneally with a clinically virulent Staphylococcus aureus.
Sonographic Measurements of the Ulnar Nerve at the Elbow With Different Degrees of Elbow Flexion

Objective To determine whether there were differences in the cross-sectional area (CSA) and the flattening ratio of the normative ulnar nerve as it passes between the medial epicondyle and the olecranon at 30° of elbow flexion versus 90° of elbow flexion. Design Bilateral upper extremities of normal healthy adult volunteers were evaluated with ultrasound. The CSA and the flattening ratio of the ulnar nerve at the elbow as it passes between the medial epicondyle and the olecranon were measured, with the elbow flexed at 30° and at 90°, by 2 operators with varying ultrasound scanning experience by using ellipse and direct tracing methods. The results from the 2 different angles of elbow flexion were compared for each individual operator. Finally, intraclass correlations for absolute agreement and consistency between the 2 raters were calculated. Setting An outpatient clinic room at a regional rehabilitation center. Participants Twenty-five normal healthy adult volunteers. Main Outcome Measurement The mean CSA and the mean flattening ratio of the ulnar nerve at 30° of elbow flexion and at 90° of elbow flexion. Results First, for the ellipse method, the mean CSA of the ulnar nerve at 90° (9.93 mm 2 ) was slightly larger than at 30° (9.77 mm 2 ) for rater 1. However, for rater 2, the mean CSA of the ulnar nerve at 90° (6.80 mm 2 ) was slightly smaller than at 30° (7.08 mm 2 ). This was found to be statistically insignificant when using a matched pairs t test and the Wilcoxon signed-rank test, with a significance level of .05. Similarly, the difference between the right side and the left side was not statistically significant. The intraclass correlations for absolute agreement between the 2 raters were not very high due to different measurement locations, but the intraclass correlations for consistency were high. Second, for the direct tracing method, the mean CSA at 90° (7.26 mm 2 ) was slightly lower than at 30° (7.48 mm 2 ). This was found to be statistically nonsignificant when using the matched pairs t test and the Wilcoxon signed-rank test with a significance level of .05. There was no significant difference in the average flattening ratio between the 2 angles for the left arm (0.54 at 30° vs 0.56 at 90°; P = .619 for the matched pairs t test and .274 for the Wilcoxon signed-rank test). However, for the right arm, the flattening ratio at 90° was significantly higher than that at 30° (0.58 at 90° vs 0.50 at 30°; P = .007 for both the matched pairs t test and the Wilcoxon signed-rank test). Conclusions The mean CSA of the ulnar nerve at the elbow at 30° was not significantly different than at 90°. However, the average flattening ratio at 90° was found to be significantly higher than at 30° for the right arm.
Evaluation of Antibiotic Feed Supplements and Crystalline Antibiotics in Chick Rations

Abstract DURING 1950 the nutritional importance of the antibiotics in the so-called APF supplements was first recognized (Stokstad and Jukes, 1950). It was not until January 1, 1951, that the definition of Antibiotic Feed Supplement, adopted by the Association of American Feed Control Officials, became effective. Prior to that date there was no organized attempt to standardize and control antibiotic content of the APF supplements. Realization of the possible wide variation in antibiotic content of APF supplements suggested a series of chick assays of commercial samples. Samples were obtained during the latter part of 1950 from commercial feed manufacturers in Maryland through the courtesy of Mr. L. E. Bopst of the Maryland State Inspection Service. Since it seemed likely that the adoption of the new definition would eliminate some of the confusion associated with the APF supplements, two series of samples of Antibiotic Feed Supplements collected by the Maryland State Inspection …
Need for information metrics: with examples from document analysis

We present an argument that progress in Information Science is inhibited by our incomplete perception of the nature of the field. An agenda for research is proposed which, we believe, will lead to more rapid progress. Specific examples are given from the field of Document Analysis.
The effect of multi-component adsorption on selectivity in ion exchange displacement systems

This paper examines chemically selective displacement chromatography using affinity ranking plots, batch displacer screening experiments, column displacements, multi-component adsorption isotherms and spectroscopy. The affinity ranking plot indicated that the displacers, sucrose octasulfate (SOS) and tatrazine, should possess sufficient affinity to displace the proteins amyloglucosidase and apoferritin over a wide range of operating conditions. In addition, the plots indicated that the separation of these proteins by displacement chromatography would be extremely difficult. Further, the two proteins were shown to have very similar retention times under shallow linear gradient conditions. When batch displacement experiments were carried out, both tartrazine and SOS exhibited significant selectivity differences with respect to their ability to displace these two proteins, in contrast to the affinity ranking plot results. Column displacement experiments carried out with sucrose octasulfate agreed with the predictions of the affinity ranking plots, with both proteins being displaced but poorly resolved under several column displacement conditions. On the other hand, column displacement with tartrazine as the displacer resulted in the selective displacement and partial purification of apoferritin. Single- and multi-component isotherms of the proteins with or without the presence of displacers were determined and were used to help explain the selectivity reversals observed in the column and batch displacement experiments. In addition, fluorescence and CD spectra suggested that the displacers did not induce any structural changes to either of the proteins. The results in this paper indicate that multi-component adsorption behavior can be exploited for creating chemically selective displacement separations.
Fate of 14 C dieldrin in a simulated terrestrial ecosystem

The disposition of14C-dieldrin (HEOD) was examined in a Terrestrial Microcosm Chamber (TMC) model ecosystem consisting of a synthetic soil medium, agricultural crops, numerous invertebrates and a microtine rodent. Residues were determined in air, soil, water, plants, invertebrates, and tissues of the vole (Microtus canicaudus) and her offspring. Design considerations for this experiment were (a) whether the test system satisfactorily measured the fate of the material applied, (b) whether the results were comparable to field and laboratory studies of the rates and extent of movement, transformation and biological effects of HEOD, and (c) whether the TMC was comparable to other microcosm test systems. The average accountability was 89% of the14C-dieldrin applied to three TMCs. At termination, the soil contained 55% (± 19%) of the14C, plants 30% (± 18%) and fauna 1.5% (± 0.9%). The vole exhibited an average Ecological Magnification index of 59.5. An average concentration of 17.7 ppm HEOD was noted in the vole brain. Dieldrin adversely affected both vole survival and reproductive performance. The results in the TMC are highly consistent with the behavior of the chemical in the natural environment and in other microcosm systems.
The Amelogenin Proteins and Enamel Development in Humans and Mice

Before a tooth erupts into the oral cavity, the mineralized enamel and dentin layers begin to develop. During these early stages of enamel formation, an abundant group of proteins known as amelogenins are secreted by ameloblast cells within the developing tooth. These proteins are required for the enamel layer to reach its normal thickness and attain its intricate structure. Human patients with amelogenin gene mutations have a condition referred to as amelogenesis imperfecta, and we have analyzed human gene defects so that we can recreate them in mice. We have generated mice with a null amelogenin mutation where no amelogenin is produced, mice that over-express normal and mutated amelogenins, and over-expressors have been mated to null mice for rescue experiments. Because there are at least 15 messages that are alternatively spliced from a single amelogenin primary RNA transcript, these approaches have begun to reveal the functions of individual amelogenin proteins during enamel development. Finally, amelogenins are processed by carefully regulated proteolytic digestion leading to many additional amelogenin peptides and it is likely that protein function is altered during this developmental process. We have also had some surprises, as one of our mouse models develops odontogenic tumors, and we know now that some of the amelogenins are expressed in other regions of the body outside of the oral cavity, and may have a role in signal transduction.
Multimodality, crossmodality, and dyslexia.

It is argued that what we call intelligent behavior is based to a great extent on our ability to analyze multimodal and crossmodal information. Acquisition and utilization of those functions seem to appear and develop greatly during the 2–4 year period in humans. Among the functions are those frequently affected in dyslexic persons. It might be possible to diagnose potential dyslexics by testing for the adequacy of those functions at that early period. In addition, limitations on the number of concepts that can be handled simultaneously may be involved in information processing in such a way as to affect both multimodality and crossmodality; this limitation seems not to be generally taken in to account by educators, especially those working with dyslexic persons.
Computing the partition function, ensemble averages, and density of states for lattice spin systems by sampling the mean

An algorithm to approximately calculate the partition function (and subsequently ensemble averages) and density of states of lattice spin systems through non-Monte-Carlo random sampling is developed. This algorithm (called the sampling-the-mean algorithm) can be applied to models where the up or down spins at lattice nodes interact to change the spin states of other lattice nodes, especially non-Ising-like models with long-range interactions such as the biological model considered here. Because it is based on the Central Limit Theorem of probability, the sampling-the-mean algorithm also gives estimates of the error in the partition function, ensemble averages, and density of states. Easily implemented parallelization strategies and error minimizing sampling strategies are discussed. The sampling-the-mean method works especially well for relatively small systems, systems with a density of energy states that contains sharp spikes or oscillations, or systems with little a priori knowledge of the density of states.
VOLATILE COMPOSITION OF BLACK PEPPER

SUMMARY Using relatively mild gas chromatographic conditions, including glass-lined injectors, glass columns and lower operating temperatures, the occurrence of a number of previously reported hydrocarbon and oxygenated terpenes in pepper oil has been confirmed. On the basis of gas chromatographic retentions and matching of infrared spectral data, and in the case of the latter compound, mass and NMR spectrometry, cis-p-2-methen-1-ol, cis-p-2,8-menthadien-1-ol and transpinocarveol have been identified as constituents of black pepper oil. Spectral data are reported which permit the partial characterization of a number of additional oxygenated compounds. The presence of artifacts due to photocatalyzed rearrangements is demonstrated and discussed.
Biomechanical and Histological Evaluation of Osteochondral Transplantation in a Rabbit Model

Background: Biomechanical and histological properties of osteochondral transplantation have not been extensively examined.Hypothesis: Osteochondral grafts have properties similar to native articular cartilage.Study Design: Controlled laboratory study.Methods: A 2.7 mm (diameter) · 4.0 mm (depth) osteochondral defect was created in 17 New Zealand white rabbit knees. An osteochondral graft, harvested from the contralateral knee, was transplanted into the defect. Eight rabbits were sacrificed each at 6 and 8 weeks.Results: The 12-week grafts (1213.6 ± 309.0 N/mm) had significantly higher stiffness than the 6-week grafts (483.1 ± 229.1 N/mm; P< .001) and of normal cartilage (774.8 ± 117.1 N/mm; P< .003). Stiffness of the 6-week grafts was significantly lower than normal cartilage (P< .036). At all time points, full-thickness defects had significantly lower stiffness than normal cartilage (P< .001). Histologically, transplanted grafts scored significantly higher than the full-thickness defects (P< .001). The d...
Synthesis of a liposome incorporated 1-carboxyalkylxanthine-phospholipid conjugate and its recognition by an RNA aptamer.

Abstract RNA or DNA aptamers have received much attention in recent literature as therapeutic agents and chromatographic matrices, however, their use in analytical methodologies is relatively unexplored. We describe here investigations aiming to combine this promising technology with versatile liposomes in a competitive assay format. Thus, a phospholipid derivative of an unsymmetrical 1,3-disubstituted xanthine (1-carboxyethyl-3-methylxanthine-DPPE) was prepared for incorporation into the lipid bilayers of dye-encapsulating liposomes. Its synthesis and characterization using GC–MS, 1 H NMR, and HPLC are described. Equilibrium filtration experiments using enzyme linked immunosorbent assays (ELISAs) were completed to assess the affinity for theophylline of an unmodified RNA aptamer and one that had been modified on the 3′ end with biotin. A dissociation constant ( K d ) for theophylline with the unmodified RNA aptamer of 0.9 μM and biotinylated aptamer of 1.0 μM was determined which showed that this modification did not affect the aptamer's affinity using this technique. The observed K d values correlated well to the previously reported value of 0.6 μM. Experiments were also carried out in a competitive manner with the prepared 1-carboxypropyl-3-methylxanthine intermediate, and the final 1-carboxypropyl-3-methylxanthine-DPPE conjugate once it had been incorporated into the bilayers of liposomes. The K d value for 1-carboxypropyl-3-methylxanthine was approximately 2.7 μM. Finally, successful binding to theophylline-analog-tagged liposomes in a competitive assay format was shown versus liposomes prepared without the tag.
Laser-induced fluorescence of i-C3H7S radicals

Abstract Iso-C 3 H 7 S radicals were generated by 248 nm photodissociation of i -C 3 H 7 SH and laser-induced fluorescence of the A-X transition was studied in the 395–435 nm region. A prominent series of bands in the excitation spectrum is interpreted as transitions to levels of the C-S stretching mode in the excited state, which has a frequency of 347 ± 10 cm −1 . Based on an expected radiative lifetime of about 800 ns, the observed zero-pressure lifetime of ≈ 120 ns suggests that all of the vibrational levels of the A state are strongly predissociated. Electronic quenching of i -C 3 H 7 S(A) is observed for a variety of collision partners.
Opportunistic Fair Scheduling in Wireless Networks: An Approximate Dynamic Programming Approach

We consider the problem of temporal fair scheduling of queued data transmissions in wireless heterogeneous networks. We deal with both the throughput maximization problem and the delay minimization problem. Taking fairness constraints and the data arrival queues into consideration, we formulate the transmission scheduling problem as a Markov decision process (MDP) with fairness constraints. We study two categories of fairness constraints, namely temporal fairness and utilitarian fairness. We consider two criteria: infinite horizon expected total discounted reward and expected average reward. Applying the dynamic programming approach, we derive and prove explicit optimality equations for the above constrained MDPs, and give corresponding optimal fair scheduling policies based on those equations. A practical stochastic-approximation-type algorithm is applied to calculate the control parameters online in the policies. Furthermore, we develop a novel approximation method--temporal fair rollout--to achieve a tractable computation. Numerical results show that the proposed scheme achieves significant performance improvement for both throughput maximization and delay minimization problems compared with other existing schemes.
Flavohemoglobin Detoxifies Nitric Oxide in Aerobic, but Not Anaerobic, Escherichia coli EVIDENCE FOR A NOVEL INDUCIBLE ANAEROBIC NITRIC OXIDE-SCAVENGING ACTIVITY

Abstract Nitric-oxide dioxygenase (NOD) and reductase (NOR) activities of flavohemoglobin (flavoHb) have been suggested as mechanisms for NO metabolism and detoxification in a variety of microbes. Mechanisms of NO detoxification were tested inEscherichia coli using flavoHb-deficient mutants and overexpressors. flavoHb showed negligible anaerobic NOR activity and afforded no protection to the NO-sensitive aconitase or the growth of anoxic E. coli, whereas the NOD activity and the protection afforded with O2 were substantial. A NO-inducible, O2-sensitive, and cyanide-resistant NOR activity efficiently metabolized NO and protected anaerobic cells from NO toxicity independent of the NOR activity of flavoHb. flavoHb possesses nitrosoglutathione and nitrite reductase activities that may account for the protection it affords against these agents. NO detoxification by flavoHb occurs most effectively via O2-dependent NO dioxygenation.
On the symmetry function of a convex set

We attempt a broad exploration of properties and connections between the symmetry function of a convex set S $${S \subset\mathbb{R}^n}$$ and other arenas of convexity including convex functions, convex geometry, probability theory on convex sets, and computational complexity. Given a point $${x \in S}$$, let sym(x,S) denote the symmetry value of x in S: $${{\bf sym}(x,S):= max\{\alpha \ge 0 : x+\alpha(x-y) \in S {\rm for every} y \in S\}}$$, which essentially measures how symmetric S is about the point x, and define $${\bf sym}({\it S}):= \max_{x\in S} \, {\bf sym}({\it x,S})$$ x* is called a symmetry point of S if x* achieves the above maximum. The set S is a symmetric set if sym(S)=1. There are many important properties of symmetric convex sets; herein we explore how these properties extend as a function of sym(S) and/or sym(x,S). By accounting for the role of the symmetry function, we reduce the dependence of many mathematical results on the strong assumption that S is symmetric, and we are able to capture and otherwise quantify many of the ways that the symmetry function influences properties of convex sets and functions. The results in this paper include functional properties of sym(x,S), relations with several convex geometry quantities such as volume, distance, and cross-ratio distance, as well as set approximation results, including a refinement of the Lowner-John rounding theorems, and applications of symmetry to probability theory on convex sets. We provide a characterization of symmetry points x* for general convex sets. Finally, in the polyhedral case, we show how to efficiently compute sym(S) and a symmetry point x* using linear programming. The paper also contains discussions of open questions as well as unproved conjectures regarding the symmetry function and its connection to other areas of convexity theory.
Evaluation of firefly luciferase bioluminescence mediated photodynamic toxicity in cancer cells.

This work investigated whether fLuc-catalyzed oxidation of d-luciferin generates sufficient light to induce photodynamic toxicity in cancer cells. Light emission was assessed via cooled CCD (charge-coupled device) camera. Parental and fLuc expressing cancer cells were exposed to subtoxic concentrations of photosensitizers (Rose Bengal or hypericin) and d-luciferin, sunlight, or lamplight. Toxicity was assessed by MTT assay. fLuc expressing cells emitted up to 500-fold higher levels of photons than parental cell lines. Although exposure to photosensitizer and sunlight reduced survival of various cell lines, survival of fLuc expressing cells incubated with photosensitizer and d-luciferin, or photosensitizer and lamplight, did not differ significantly from parental or untreated cells. Contesting recent reports, fLuc bioluminescence does not generate sufficient photons to induce Rose Bengal or hypericin photodynamic toxicity in a range of malignant and nonmalignant cell lines, and is not suitable as a generalizable approach to antineoplastic therapy.
The reliability and validity of the Four Square Step Test for people with balance deficits secondary to a vestibular disorder.

Abstract Whitney SL, Marchetti GF, Morris LO, Sparto PJ. The reliability and validity of the Four Square Step Test for people with balance deficits secondary to a vestibular disorder. Objective To determine the reliability and validity of the Four Square Step Test (FSST) for use in people with balance deficits secondary to vestibular disorders, who frequently report falling and have difficulty with changes of direction. Design Cross-sectional descriptive study. Setting Outpatient clinic. Participants Thirty-two people with balance deficits secondary to vestibular disorders (mean age, 63.7±17.8y) who were currently enrolled in a vestibular physical therapy program agreed to participate. Interventions Participants performed the FSST, the Timed Up & Go (TUG) test, an 11-m walk test during which walking speed was recorded, and the Dynamic Gait Index (DGI) and completed the Dizziness Handicap Inventory (DHI) and the Activities-Specific Balance Confidence (ABC) Scale. Main Outcome Measures The main outcome measures were the FSST time, TUG results, DGI score, gait velocity, and DHI and ABC scores. Number of fall risk factors, as determined by published scores for people at risk for falling on the TUG test and gait speed, and number of falls were compared with FSST scores. Results The FSST has good reliability (intraclass correlation coefficient, model 3,1: .93; 95% confidence interval, .86–.96) and had good correlations with the other gait measures (correlation coefficients for the TUG, .69; gait speed, .65; DGI, −.51) and poor correlations with the DHI and the ABC (DHI, −.13; ABC, −.12). Multivariate linear regression showed that 51.5% of FSST performance was explained by TUG score and gait speed. The mean FSST time differed significantly between groups with 0 (n=12), 1 (n=12), or 2 to 3 (n=8) risk factors for falls (analysis of variance, F=10.02; P Conclusions The FSST is a reliable and valid tool for measuring the ability to perform multidirectional movements in people with balance deficits secondary to vestibular disorders.
Rhetorical criticism as a method for examining cultural pressures on organizational form

Purpose – The purpose of this paper is to provide a rationale and step‐by‐step description of how to use rhetorical criticism as a method for accounting for organizational isomorphism in organizational fields.Design/methodology/approach – The idea that rhetoric is an important form of organizational discourse has gained interest among organizational scholars in recent years. Institutional theorists, especially, have been willing to embrace the “rhetorical turn” in organization studies. These scholars recognize that rhetoric plays an important role in creating, maintaining, and disrupting organizational and institutional orders. This paper adds to this research agenda by suggesting that organizational isomorphism can be partly understood as a rhetorical phenomenon. A method of rhetorical criticism – a qualitative approach for analyzing the rhetorical dimensions of texts and practice – and its efficacy for institutional research is explicated. Using a popular television program about crime scene investigati...
Sequence of events leading to seizure activity at the level of a hippocampal epileptic pacemaker

Abstract An analysis of the sequence of synaptic events leading to seizure activity was performed in chronic awake animals at the level of a hippocampal “epileptic pacemaker” by recording with extracellular microelectrodes the responses induced by ipsilateral and contralateral hippocampal stimulation, in different layers of the field CA1 of the dorsal hippocampus. The first event marking the beginning of the epileptic buildup was an increased voltage and a delayed decay of the apical positive slow wave. Superimposed on it, spike discharges were recorded; some of them were developed at the peak of the wave, and some others superimposed on the falling phase of the slow wave. Later during stimulation similar changes occurred at the level of the basal dendrites, where a slow negative wave was potentiated during the epileptic buildup. The active involvement of pyramidal soma occurred later still during the buildup apparently as a consequence of orthodromically conducted dendritic spikes. An initial positive field was abruptly replaced by a long-lasting negative field with discharges and later on with spike inactivation. Concurrently with the first preepileptic changes of apical dendritic potential, somatic unitary small-amplitude discharges (probably from interneurones) were recorded at the apical dendritic level. Their frequency and number gradually increased during the epileptic buildup. It is assumed that the epileptogenic buildup developed independently at the apical and basal dendritic levels. An estimation of current density lines showed separate sinks and sources of current at the two levels during the preseizure period. The main excitatory changes occurred at the apical dendritic level, in spite of the positivity of the preepileptic wave at this level. It is probable that reverberating neuronal chains were built up between usually inactive interneurons and the apical dendritic branches. Pyramidal discharges probably reactivated the interneurons.
A strategy for the integration of production planning and reactive scheduling in the optimization of a hydrogen supply network

Abstract In this paper, we address the integration of production planning and reactive scheduling for the optimization of a hydrogen supply network consisting of five plants, four inter-connected pipelines and 20 customers. We present multiperiod mixed integer nonlinear programming (MINLP) models for both the planning and scheduling levels. The planning model includes complex pricing functions resulting from deregulation, with a simplified pipeline description and determines feed and energy prices, as well as production levels, for a monthly horizon divided into 12-h time periods. Prices are fixed on the scheduling level, while a detailed pipeline model is included, to determine the on/off status and load steps of compressors on an hourly basis, in order to satisfy the actual demands as they become known while adhering to pressure constraints. In addition, we propose a solution methodology where the demand forecast is updated and the planning model is rerun every 12 h, while the scheduling model is run every hour and information is passed between the two levels to facilitate integration. We show that the planning model quickly becomes intractable and propose a heuristic solution method for this level based on Lagrangean decomposition. Results show that the proposed Lagrangean decomposition heuristic reduces the computational effort for solving the planning model by more than an order of magnitude compared to the commercial MINLP solver DICOPT++. It is also shown that for the majority of the plants, the power consumption and hydrogen production from the scheduling level agrees with the planning level. In some cases, however, the integration is hampered by the presence of nonlinearities, especially on the scheduling level, that lead to suboptimal or infeasible solutions. These nonlinearities need to be further addressed before the proposed methodology can be implemented in practice.
Autocatalytic Patterning with Silver Using Tin(II) Chloride Sensitizer

A silver mirror can be deposited on many types of surfaces from the reduction of the silver−diammine complex by a reducing sugar as proposed by Kemp in this Journal. Three extensions of Kemp’s demonstration that highlight the role of SnCl2 sensitizer in the deposition of a silver mirror on surfaces are presented. The demonstration extensions can be easily modified for audience participation. The results are visually striking and the silver-coated surfaces formed can be kept as decorations. The demonstrations can be used to reinforce diverse concepts such as complex formation, oxidation−reduction reactions, carbonyl and carbohydrate chemistry, nanoscale structures, and use of one-way mirrors in forensics.
Lymphoma and multiple myeloma mortality in relation to magnetic field exposure among electric utility workers

Associations between occupational magnetic field exposure and non-Hodgkin's lymphoma (NHL), Hodgkin's disease, and multiple myeloma mortality were evaluated in 138,905 electrical utility workers. A job-exposure matrix based on measured magnetic fields was used to derive individual exposure estimates. There was a small positive association between all NHL and low-grade NHL and duration of employment in any magnetic field-exposed job, but only up to 20 years. Cumulative magnetic field exposure was associated with a rising, then falling, risk of NHL. Rate ratios for intermediate/high-grade lymphoma were increased for the highest levels of lifetime cumulative exposure (RR = 3.7 and RR = 2.3), and were most pronounced for those exposures occurring 10-20 years previously. Hodgkin's disease and multiple myeloma mortality did not appear to be associated with exposure. Associations were stronger for NHL subgroups, suggesting that further analysis by subgroup may be warranted, but the absence of dose-response gradients diminishes the likelihood that associations represent causal relationships.
Teriparatide (1-34 human PTH) Regulation of Osterix During Fracture Repair

Based on remarkable success of PTH as an anabolic drug for osteoporosis, case reports of off-label use of teriparatide (1-34 PTH) in patients with complicated fractures and non-unions are emerging. We investigated the mechanisms underlying PTH accelerated fracture repair. Bone marrow cells from 7 days 40 microg/kg of teriparatide treated or saline control mice were cultured and Osx and osteoblast phenotypic gene expression assessed by real-time RT-PCR in these cells. Fractured animals injected daily with either saline or 40 microg/kg of teriparatide for up to 21 days were X-rayed and histological assessment performed, as well as immunohistochemical analyses of the Osx expression in the fracture callus. Osx, Runx2 and osteoblast or chondrocyte phenotypic gene expression was also assessed in fracture calluses. Our data shows that Osx and Runx2 are up-regulated in marrow-derived MSCs isolated from mice systemically treated with teriparatide. Furthermore, these MSCs undergo accelerated osteoblast maturation compared to saline injected controls. Systemic teriparatide treatments also accelerated fracture healing in these mice concomitantly with increased Osx expression in the PTH treated fracture calluses compared to controls. Collectively, these data suggest a mechanism for teriparatide mediated fracture healing possibly via Osx induction in MSCs.
Changing Competencies of Hospitality Leaders: A 25-Year review

Significant changes in the competitive environment of business and education, along with changes in the macro-environment, point to the need for curriculum reform in hospitality management. Determining relevant competencies and skill sets has helped human resource managers over the years to improve hiring and selection practices, in developing strategies to retain managers, and in career planning initiatives. This study is a review of competencies that have been emphasized by hospitality industry leaders for success in the field over the years, and reports similarities as well as key changes in skills demanded of students graduating from hospitality management programs.
Recent advances in arsenic carcinogenesis: modes of action, animal model systems, and methylated arsenic metabolites.

Recent advances in our knowledge of arsenic carcinogenesis include the development of rat or mouse models for all human organs in which inorganic arsenic is known to cause cancer–skin, lung, urinary bladder, liver, and kidney. Tumors can be produced from either promotion of carcinogenesis protocols (mouse skin and lungs, rat bladder, kidney, liver, and thyroid) or from complete carcinogenesis protocols (rat bladder and mouse lung). Experiments with p53+/− and K6/ODC transgenic mice administered dimethylarsinic acid or arsenite have shown some degree of carcinogenic, cocarcinogenic, or promotional activity in skin or bladder. At present, with the possible exception of skin, the arsenic carcinogenesis models in wild-type animals are more highly developed than in transgenic mice. Recent advances in arsenic metabolism have suggested that methylation of inorganic arsenic may be a toxification, rather than a detoxification, pathway and that trivalent methylated arsenic metabolites, particularly monomethylarsonous acid and dimethylarsinous acid, have a great deal of biological activity. Accumulating evidence indicates that these trivalent, methylated, and relatively less ionizable arsenic metabolites may be unusually capable of interacting with cellular targets such as proteins and even DNA. In risk assessment of environmental arsenic, it is important to know and to utilize both the mode of carcinogenic action and the shape of the dose–response curve at low environmental arsenic concentrations. Although much progress has been recently made in the area of arsenic's possible mode(s) of carcinogenic action, a scientific concensus has not yet been reached. In this review, nine different possible modes of action of arsenic carcinogenesis are presented and discussed–induced chromosomal abnormalities, oxidative stress, altered DNA repair, altered DNA methylation patterns, altered growth factors, enhanced cell proliferation, promotion/progression, gene amplification, and suppression of p53.
Molecular simulation study of assembly of DNA-grafted nanoparticles: effect of bidispersity in DNA strand length

In this paper, we use molecular dynamics simulations to study the assembly of DNA-grafted nanoparticles to demonstrate specifically the effect of bidispersity in grafted DNA strand length on the thermodynamics and structure of nanoparticle assembly at varying number of grafted single-stranded DNA (ssDNA) strands and number of guanine/cytosine (G/C) bases per strand. At constant number of grafted ssDNA strands and G/C nucleotides per strand, as bidispersity in strand lengths increases, the number of nanoparticles that assemble as well as the number of neighbours per particle in the assembled cluster increases. When the number of G/C nucleotides per strand in short and long strands is equal, the long strands hybridise with the other long strands with higher frequency than the short strands hybridise with short/long strands. This dominance of the long strands leads to bidisperse systems having similar thermodynamics to that in corresponding systems with monodisperse long strands. Structurally, however, as a ...
Mixed low- and high-grade non-muscle-invasive bladder cancer: a histological subtype with favorable outcome

Objective To determine whether heterogeneity of tumor grade affects the response to Bacillus Calmette-Guerin (BCG) treatment for patients with non-muscle-invasive bladder cancer (NMIBC).
Micellar microstructure of linear and guerbet micelles: Fluorescence probe study

Abstract Pyrene, 1-decylpyrene, and 1,10-bis(1-pyrene)decane were used as fluorescence probes to differentiate the microstructure of micelles formed from linear and Guerbet surfactants. The pyrene probes experience a higher micropolarity and microfluidity in a Guerbet micelle compared with the linear counterpart.
Vincent van Gogh and the thujone connection.

During his last two years Vincent van Gogh experienced fits with hallucinations that have been attributed to a congenital psychosis. But the artist admitted to episodes of heavy drinking that were amply confirmed by colleagues and there is good evidence to indicate that addiction to absinthe exacerbated his illness. Absinthe was distilled from an alcoholic steep of herbs. Wormwood (Artemisia absinthium) was the most significant constituent because it contributed thujone. This terpene can cause excitation, convulsions that mimic epilepsy, and even permanent brain damage. Statements in van Gogh's letters and from his friends indicate that he had an affinity for substances with a chemical connection to thujone; the documented examples are camphor and pinene. Perhaps he developed an abnormal craving for terpenes, a sort of pica, that would explain his attempts to eat paints and so on, which were previously regarded as unrelated absurdities. (JAMA1988;260:3042-3044)
Effects of submicrometer-sized particles on microdroplet lasing.

We report the threshold emission characteristics of lasing from microdroplets that consist of Rhodamine 6G dye in an ethanol solution that contains undoped polystyrene latex spheres. The addition of latex particles to the droplets suppresses lasing. Our findings indicate that, for a fixed Rhodamine 6G concentration and fixed pump intensity, lasing ceases when a certain total-threshold latex particle surface area is reached in the droplet, independent of latex particle size. A possible explanation for these findings is the Forster-assisted annihilation of Rhodamine 6G dye lasing levels, facilitated by the adsorption of dye molecules on the surfaces of latex particles.
MENARCHE AND THE (HETERO)SEXUALIZATION OF THE FEMALE BODY

Menarche—or a woman's first menstrual period—is a central aspect of body politics. Through explorations of oral and written narratives, I suggest that girls' subjective sense of themselves as maturing women at menarche develops simultaneously with a process of sexualization whereby young women experience themselves as sexualized, and their bodies are produced as sexual objects. While women internalize negative scripts associated with the bleeding female body, they also respond with consciousness and resistance.
A three-dimensional model of anisotropic hardening in metals and its application to the analysis of sheet metal formability

Abstract The hardening model proposed by Z. Mroz based on the uniaxial fatigue behavior of many metals is adopted to derive an incremental constitutive equation for general three-dimensional problems. This constitutive law is then employed in the analysis of metal forming problems to assess the influence of loading cycles, of the types involved in standard forming processes, on the ultimate formability of sheet metals. The predicted forming limit curves differ quantitatively from results obtained via an isotropie hardening model and differ qualitatively from those obtained via a kinematic model. Also investigated are the effects of such loading cycles on material response to simple tensile loading, which is often used to characterize a material. Significant differences between the present model and the other two models considered are observed in such characterizers of simple tensile behavior as the stress-strain curve, the anisotropy parameter and the uniform elongation. These differences suggest a rather simple experiment to identify the proper material model to be used in analyses of problems which involve loading cycles. Comparisons with some experimental results reveal that the employment of an anisotropic hardening model, such as the generalized Mroz model derived herein, is indeed crucial in accurately predicting material response to complicated loading histories.
Prenatal Diagnosis of a Persistent Fifth Aortic Arch, Pulmonary‐to‐Systemic type: An Unusual Association with Evolving Aortic Coarctation

Persistent fifth arch (PFA) is a rare anomaly that is often underdiagnosed and missed. Different PFA types that have been reported in the literature are systemic-to-systemic type (most common), systemic-to-pulmonary artery (PA), and PA-to-systemic types. The designations of systemic-to-PA or PA-to-systemic are based on if the PFA is a source of PA or systemic blood flow, respectively, in the setting of critical proximal obstruction (pulmonary atresia or aortic atresia). This case describes an unusual PFA, which connects the distal PA to distal ascending aorta; however, it is not associated with critical proximal obstruction, and while it appeared to be an incidental finding in early gestation, progressive serial distal obstruction of the left fourth arch was seen to develop. This case highlights that prenatal diagnosis of PFA is possible and that once a diagnosis is made, serial fetal echocardiograms should be performed to evaluate for evolving lesions.
Gamma-irradiation of 7-ketocholesterol in aqueous dispersions and liposomes

7-Ketocholesterol in aqueous sodium stearate dispersions or incorporated into liposomes was exposed to gamma radiation at 0–4°C to a dose of 50 kGy. Substrate degradation was noted in all systems, but occurred to a much greater extent in dispersions (≈90%) than in liposomes (0–25%). The difference in degree of degradation is attributed to dissimilarities in the micro-environment of 7-ketocholesterol in the two systems. The principal decomposition product was identified as 7-ketocholestanol, a compound that can arise from hydrogenation of the double bond of the starting material. Also detected, but in lower concentration, were the epimeric 7-hydroxycholesterols resulting from the reduction of the original carbonyl function. Both 7-ketocholestanol and the epimeric 7-hydroxycholesterols are believed to be secondary species generated by the interaction of the starting material with the primary radiolysis products of water. In addition, many minor degradation products were noted but not identified.