bluuebunny/crossref_metadata_2025 huggingface dataset:
The design and application of effective written instructional material: a review of published work
Authors: Mayberry John F
Published: September 2007

This review will consider the evidence base for the format of educational material drawing on academic papers and the practice of the design industry. The core issues identified from the review are drawn together in guidelines for educational posters, text and web based material. The review deals with the design of written material both for use in leaflets and books as well as the impact of factors such as font type and size as well as colour on poster design. It sets these aspects of educational material within a research framework, which looks at impact on learning and subsequent change in practice. These issues are examined through a practical example of a poster designed for a regional gastroenterology meeting.
Environmental influences on the high mortality from colorectal cancer in African Americans
Authors: Sharma Sumit , O'Keefe Stephen J D
Published: September 2007

Colon cancer is the second leading cause of cancer related death in American adults. The incidence and mortality are highest in African Americans (AAs) (incidence: 52 per 100 000) and lowest in American Hispanics (37 per 100 000). Comparative studies with Native Africans (<5 per 100 000) suggest that genetic susceptibility is an unlikely explanation and that environmental influences are to blame. Studies have suggested that risk is high because of excessive intakes of animal meat and fat products and differences in colonic bacterial metabolism, and that preventative and therapeutic management of colon cancer is compromised by the development of greater tumour virulence possibly resulting from disparities in educational and insurance status, screening behaviour, treatment patterns, social support, and access to and use of health care facilities. It should be possible to reduce the unacceptably higher rates of morbidity and mortality from colon cancer in AAs by dietary and lifestyle changes aimed at suppressing excessive intakes of animal meat and fat products, increasing the consumption of fresh fruit and vegetables, controlling energy balance, and by developing strategies to improve the availability, use and accessibility to health care resources.
Survey of the use of epinephrine (adrenaline) for anaphylaxis by junior hospital doctors
Authors: Jose Ricardo , Clesham Gerald J
Published: September 2007

Background

Anaphylaxis is a life threatening reaction where prompt and appropriate management can save lives. Epinephrine (adrenaline) is the treatment of choice; however, the recommended dose and route of administration of epinephrine used in the management of anaphylaxis is different from that used in the management of cardiac arrest.

Objective

To investigate how junior doctors would administer epinephrine in a case of anaphylactic shock in an adult patient.

Methods

Junior medical staff in two district general hospitals were assessed with a short questionnaire.

Results

95 junior hospital doctors were assessed. The majority (94%) would administer epinephrine as the life saving drug of choice, but only 16.8% would administer it as recommended by the UK Resuscitation Council Guidelines.

Conclusion

Junior doctors may be called to make immediate management decisions in patients with anaphylaxis; however, widespread confusion exists regarding the dose and route of administration of epinephrine. Strategies to improve education and access to appropriate drugs are needed. A labelled “anaphylaxis box” on every resuscitation trolley, containing the dose of epinephrine with clear labelling for intramuscular use, may be one solution.
Muscle metabolic responses during 16 hours of intermittent heavy exercise
Authors: Green H.J. , Duhamel T.A. , Holloway G.P. , Moule J. , Ouyang J. , Ranney D. , Tupling A.R.
Published: September 2007

The alterations in muscle metabolism were investigated in response to repeated sessions of heavy intermittent exercise performed over 16 h. Tissue samples were extracted from the vastus lateralis muscle before (B) and after (A) 6 min of cycling at approximately 91% peak aerobic power at repetitions one (R1), two (R2), nine (R9), and sixteen (R16) in 13 untrained volunteers (peak aerobic power = 44.3 ± 0.66 mL·kg–1·min–1, mean ± SE). Metabolite content (mmol·(kg dry mass)–1) in homogenates at R1 indicated decreases (p < 0.05) in ATP (21.9 ± 0.62 vs. 17.7 ± 0.68) and phosphocreatine (80.3 ± 2.0 vs. 8.56 ± 1.5) and increases (p < 0.05) in inosine monophosphate (IMP, 0.077 ± 0.12 vs. 3.63 ± 0.85) and lactate (3.80 ± 0.57 vs. 84.6 ± 10.3). The content (µmol·(kg dry mass)–1) of calculated free ADP ([ADPf], 86.4 ± 5.5 vs. 1014 ± 237) and free AMP ([AMPf], 0.32 ± 0.03 vs. 78.4 ± 31) also increased (p < 0.05). No differences were observed between R1 and R2. By R9 and continuing to R16, pronounced reductions (p < 0.05) at A were observed in IMP (72.2%), [ADPf] (58.7%), [AMPf] (85.5%), and lactate (41.3%). The 16-hour protocol resulted in an 89.7% depletion (p < 0.05) of muscle glycogen. Repetition-dependent increases were also observed in oxygen consumption during exercise. It is concluded that repetitive heavy exercise results in less of a disturbance in phosphorylation potential, possibly as a result of increased mitochondrial respiration during the rest-to-work non-steady-state transition.
Ultrastructural basis of airway smooth muscle contractionThis article is one of a selection of papers published in the Special Issue on Recent Advances in Asthma Research.
Authors: Seow Chun Y. , Paré Peter D.
Published: September 2007

The sliding filament theory of contraction that was developed for striated muscle is generally believed to be also applicable to smooth muscle. However, the well-organized myofilament lattice (i.e., the sarcomeric structure) found in striated muscle has never been clearly delineated in smooth muscle. There is evidence that the myofilament lattice in some smooth muscles, such as airway smooth muscle, is malleable; it can be reshaped to fit a large range of cell dimensions while the maximal overlap between the contractile filaments is maintained. In this review, some early models of the structurally static contractile apparatus of smooth muscle are described. The focus of the review, however, is on the recent findings supporting a model of structurally dynamic contractile apparatus and cytoskeleton for airway smooth muscle. A list of unanswered questions regarding smooth muscle ultrastructure is also proposed in this review, in the hope that it will provide some guidance for future research.
The time course of inflammatory cytokine secretion in a rat model of postoperative pain does not coincide with the onset of mechanical hyperalgesia
Authors: Loram Lisa C. , Themistocleous Andreas C. , Fick Linda G. , Kamerman Peter R.
Published: September 2007

We characterized the time course of inflammatory cytokine release at the site of injury and in plasma after surgery on the rat tail. Anesthetized Sprague–Dawley rats had a 20 mm long incision made through the skin and fascia of their tails. Control rats were anesthetized, but no incision was made. Blood and tissue samples were taken 2 h and 1, 2, 4, and 8 days after surgery and analysed by ELISA for interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and cytokine-induced neutrophil chemoattractant-1 (CINC-1). In another group of rats, daily behavioral measurements were made of the rats’ responses to a blunt noxious mechanical stimulus (4 Newtons) applied to their tails. Primary hyperalgesia developed within 2 h of surgery and lasted for 6 days. The tissue concentrations of IL-1β, IL-6, and CINC-1 increased within 24 h of surgery, and TNF-α concentration increased within 48 h of surgery. Thereafter, cytokine concentrations remained elevated for 4 (IL-1β and IL-6) to 8 days (CINC-1, TNF-α) after surgery. Control animals did not develop hyperalgesia and no changes in cytokines concentrations were detected. Thus, in our model of postoperative pain, secretion of inflammatory cytokines IL-1β, IL-6, TNF-α, and CINC-1 was not essential for the initiation of postoperative hyperalgesia.
Biophysical basis for airway hyperresponsivenessThis article is one of a selection of papers published in the Special Issue on Recent Advances in Asthma Research.
Authors: An Steven S. , Fredberg Jeffrey J.
Published: September 2007

Airway hyperresponsiveness is the excessive narrowing of the airway lumen caused by stimuli that would cause little or no narrowing in the normal individual. It is one of the cardinal features of asthma, but its mechanisms remain unexplained. In asthma, the key end-effector of acute airway narrowing is contraction of the airway smooth muscle cell that is driven by myosin motors exerting their mechanical effects within an integrated cytoskeletal scaffolding. In just the past few years, however, our understanding of the rules that govern muscle biophysics has dramatically changed, as has their classical relationship to airway mechanics. It has become well established, for example, that muscle length is equilibrated dynamically rather than statically, and that in a dynamic setting nonclassical features of muscle biophysics come to the forefront, including unanticipated interactions between the muscle and its time-varying load, as well as the ability of the muscle cell to adapt (remodel) its internal microstructure rapidly in response to its ever-changing mechanical environment. Here, we consider some of these emerging concepts and, in particular, focus on structural remodeling of the airway smooth muscle cell as it relates to excessive airway narrowing in asthma.
Relaxation of canine airway smooth muscleThis article is one of a selection of papers published in the Special Issue on Recent Advances in Asthma Research.
Authors: Fust Anita , Stephens Newman L.
Published: September 2007

Relaxation of airway smooth muscle is an inadequately understood yet critical process that, if impaired, may have significant implications for asthma. Here we explore why relaxation is an important process to consider, how it may determine airway hyperresponsiveness, and some of the factors that influence relaxation of the airway smooth muscle. These include mechanical and biochemical factors such as deep inspirations or large amplitude oscillation of the muscle, plastic properties of the muscle, the load the muscle experiences, calcium, phosphorylation of the myosin light chain, cytoskeletal proteins, and sensitization.
Dendritic cells in allergic airway inflammationThis article is one of a selection of papers published in the Special Issue on Recent Advances in Asthma Research.
Authors: Bharadwaj Arpita S. , Bewtra Againdra K. , Agrawal Devendra K.
Published: September 2007

Dendritic cells (DCs) are primary antigen-presenting cells involved in interactions with T cells leading to the proliferation of TH1 or TH2 cell types. In asthma, predominance of TH2 cells appears to be responsible for disease pathogenesis. Differentiation of TH2 cells is driven by a variety of factors such as the expression of high levels of costimulatory molecules, the cytokine profile, and the subset of DCs. Many inflammatory cells involved in the pathogenesis of asthma either directly or indirectly modulate DC function. Traditional treatments for asthma decrease the number of airway DCs in animals as well as in patients with asthma. Immunomodulators including interleukin (IL)-10, transforming growth factor (TGF)-β, cytosine-phosphate-guanosine-containing oligodeoxynucleotides (CpG-ODN), 1α,25-dihydroxyvitamin D3, and fetal liver tyrosine kinase 3 ligand (Flt3L) are involved in the modulation of the function of DCs. Based on the critical review of the interaction between DCs and other inflammatory cells, we propose that activation of T cells by DCs and sensitization to inhaled allergen and resulting airway inflammation are dependent on plasmacytoid and myeloid subset of lung DCs to induce an immune response or tolerance and are tightly regulated by T-regulatory cells. Effects of various therapeutic agents to modulate the function of lung myeloid DCs have been discussed.
MARKOVIAN QUEUES WITH CORRELATED ARRIVAL PROCESSES
Authors: HUNTER JEFFREY J.
Published: September 2007

In an attempt to examine the effect of dependencies in the arrival process on the steady state queue length process in single server queueing models with exponential service time distribution, four different models for the arrival process, each with marginally distributed exponential inter-arrivals to the queueing system, are considered. Two of these models are based upon the upper and lower bounding joint distribution functions given by the Fréchet bounds for bivariate distributions with specified marginals, the third is based on Downton's bivariate exponential distribution and fourthly the usual M/M/1 model. The aim of the paper is to compare conditions for stability and explore the queueing behavior of the different models.
A METHOD FOR SOLVING LINEAR PROGRAMMING PROBLEMS WITH FUZZY PARAMETERS BASED ON MULTIOBJECTIVE LINEAR PROGRAMMING TECHNIQUE
Authors: ZANGIABADI M. , MALEKI H. R.
Published: September 2007

In the real-world optimization problems, coefficients of the objective function are not known precisely and can be interpreted as fuzzy numbers. In this paper we define the concepts of optimality for linear programming problems with fuzzy parameters based on those for multiobjective linear programming problems. Then by using the concept of comparison of fuzzy numbers, we transform a linear programming problem with fuzzy parameters to a multiobjective linear programming problem. To this end, we propose several theorems which are used to obtain optimal solutions of linear programming problems with fuzzy parameters. Finally some examples are given for illustrating the proposed method of solving linear programming problem with fuzzy parameters.
A CHANCE-CONSTRAINED PORTFOLIO SELECTION PROBLEM UNDER t-DISTRIBUTION
Authors: WANG YI , CHEN ZHIPING , ZHANG KECUN
Published: September 2007

Aimed at better modeling stock returns and finding robustly optimal investment decisions, a new portfolio selection model is proposed in this paper. The model differs from existing ones in following ways: multiple market frictions are taken into account simultaneously; the adopted multivariate t-distribution can capture the well-recognized fat tails in the return data by adding only one more parameter relative to the normal; the downside loss risk is controlled by a chance constraint which, including VaR as a special case, is flexible in terms of adjusting the threshold return and the loss probability level; one important advantage about the combination of the latter two innovations is that the derived asset allocation model can be transformed into a second-order cone program or a linear program, which can be easily solved in polynomial time. Empirical results based on some S&P 500 component stocks not only demonstrate the practicality of our new model, but show how different model parameters could affect the optimal portfolio selection. This is very useful in guiding investors to choose a correct model and to find the investment strategy most suitable for their specific purpose.
THE PLANCK SATELLITE: STATUS & PERSPECTIVES
Authors:   on behalf of the Planck Collaboration., BOUCHET F. R.
Published: September 2007

I review the status of development of the PLANCK project which is slated for launch mid-2008. In particular, I illustrate the type of scientific results to expect in light of the current knowledge of the two on-board instruments. Indeed both instruments have now been delivered to industry for integration and they have been fully tested. This leads us to anticipate that the steady and fast rate of progress enjoyed by cosmology, in particular through the constraints given by the analysis of the Cosmic Microwave background (CMB) will continue unabated in the years to come.
SOME ISSUES IN CMB POLARIZATION OBSERVATION
Authors: NG KIN-WANG
Published: September 2007

As a huge amount of high-resolution data made by future high-sensitivity CMB experiments comes along, it is timely to study some important issues such as asymmetric beam effects and the mixing and separation of the E-mode and B-mode polarization in order to make efficient and unbiased estimation of the CMB anisotropy power spectra.
PROBING THE CLUSTER MASS DISTRIBUTION USING SUBARU WEAK LENSING DATA
Authors: UMETSU KEIICHI , TAKADA MASAHIRO , BROADHURST TOM
Published: September 2007

We present results from a weak lensing analysis of the galaxy cluster A1689 (z = 0.183) based on deep wide-field imaging data taken with Suprime-Cam on Subaru telescope. A maximum entropy method has been used to reconstruct directly the projected mass distribution of A1689 from combined lensing distortion and magnification measurements of red background galaxies. The resulting mass distribution is clearly concentrated around the cD galaxy, and mass and light in the cluster are similarly distributed in terms of shape and orientation. The azimuthally-averaged mass profile from the two-dimensional reconstruction is in good agreement with the earlier results from the Subaru one-dimensional analysis of the weak lensing data, supporting the assumption of quasi-circular symmetry in the projected mass distribution of the cluster.
GEOMETRIC MEAN NEUTRINO MASS RELATION
Authors: HE XIAO-GANG , ZEE A.
Published: September 2007

Present experimental data from neutrino oscillations have provided much information about the neutrino mixing angles. Since neutrino oscillations only determine the mass squared differences [Formula: see text], the absolute values for neutrino masses mi, can not be determined using data just from oscillations. In this work we study implications on neutrino masses from a geometric mean mass relation [Formula: see text] which enables one to determined the absolute masses of the neutrinos. We find that the central values of the three neutrino masses and their 2σ errors to be m1 = (1.58 ± 0.18) meV , m2 = (9.04 ± 0.42) meV , and m3 = (51.8 ± 3.5) meV . Implications for cosmological observation, beta decay and neutrinoless double beta decays are discussed.
SCALAR DARK MATTER EFFECTS IN HIGGS AND TOP QUARK DECAYS
Authors: HE XIAO-GANG , TSAI HO-CHIN , LI TONG , LI XUE-QIAN
Published: September 2007

We study possible observational effects of scalar dark matter, the darkon D, in Higgs h and top quark t decay processes, h → DD and t → cDD in the minimal Standard Model (SM) and its two Higgs doublet model (THDM) extension supplemented with a SM singlet darkon scalar field D. We find that the darkon D can have a mass in the range of sub-GeV to several tens of GeV, interesting for LHC and ILC colliders, to produce the required dark matter relic density. In the SM with a darkon, t → cDD only occurs at loop level giving a very small rate, while the rate for Higgs decay h → DD can be large. In THDM III with a darkon, where tree level flavor changing neutral current (FCNC) interaction exists, a sizable rate for t → cDD is also possible.
THE SOCIAL NETWORK OF CONTEMPORARY POPULAR MUSICIANS
Authors: PARK JUYONG , CELMA OSCAR , KOPPENBERGER MARKUS , CANO PEDRO , BULDÚ JAVIER M.
Published: September 2007

In this paper, we analyze two social network datasets of contemporary musicians constructed from allmusic.com (AMG), a music and artists' information database: one is the collaboration network in which two musicians are connected if they have performed or produced an album together, and the other is the similarity network in which they are connected if they were musically similar according to the music experts. We find that, while both networks exhibit typical features of social networks such as high transitivity (clustering), we find that they differ significantly in some key network features such as the degree and the betweenness distributions. We believe that this highlights the fundamental differences in the construction mechanism (self-organized collaboration and human-perceived similarity) of the new networks.
RANDOM WALKS ON DIRECTED NETWORKS: THE CASE OF PAGERANK
Authors: FORTUNATO SANTO , FLAMMINI ALESSANDRO
Published: September 2007

PageRank, the prestige measure for Web pages used by Google, is the stationary probability of a peculiar random walk on directed graphs, which interpolates between a pure random walk and a process where all nodes have the same probability of being visited. We give some exact results on the distribution of PageRank in the cases in which the damping factor q approaches the two limit values 0 and 1. When q → 0 and for several classes of graphs the distribution is a power law with exponent 2, regardless of the in-degree distribution. When q → 1 it can always be derived from the in-degree distribution of the underlying graph, if the out-degree is the same for all nodes.
SYNCHRONIZATION IN ECOLOGICAL NETWORKS: A BYPRODUCT OF DARWINIAN EVOLUTION?
Authors: DERCOLE FABIO , LOIACONO DANIELE , RINALDI SERGIO
Published: September 2007

The paper considers the evolution of a particular class of networks of identical chaotic oscillators, namely that of ecological networks. In these networks, nodes represent patches where a certain number of plant and animal populations interact on ecological timescale, arcs represent migration flows due to dispersal, and Darwinian evolution is responsible for variations, on a longer evolutionary timescale, of the demographic parameters characterizing the populations. Up to now, this problem has been mainly studied with reference to single-population patches described by one-dimensional discrete-time models and by considering only the dispersal rates of migrating populations as an evolving trait. Here, we propose a method of investigation which allows to study multipopulation patches described by continuous-time models with evolving traits influencing various demographic parameters (including or not dispersal). The method is casted within the frame of the so-called master stability function approach for the analysis of synchronization of coupled systems, and the results obtained in a first and very simple application support the conjecture that evolution drives ecological networks toward weak forms of synchronization.
INTERNET DATA PACKET TRANSPORT: FROM GLOBAL TOPOLOGY TO LOCAL QUEUEING DYNAMICS
Authors: LEE H. K. , GOH K.-I. , KAHNG B. , KIM D.
Published: September 2007

We study structural feature and evolution of the Internet at the autonomous systems level. Extracting relevant parameters for the growth dynamics of the Internet topology, we construct a toy model for the Internet evolution, which includes the ingredients of multiplicative stochastic evolution of nodes and edges and adaptive rewiring of edges. The model reproduces successfully structural features of the Internet at a fundamental level. We also introduce a quantity called the load as the capacity of node needed for handling the communication traffic and study its time-dependent behavior at the hubs across years. The load at hub increases with network size N as ~ N1.8. Finally, we study data packet traffic in the microscopic scale. The average delay time of data packets in a queueing system is calculated, in particular, when the number of arrival channels is scale-free. We show that when the number of arriving data packets follows a power law distribution, ~ n-λ, the queue length distribution decays as n1-λ and the average delay time at the hub diverges as ~ N(3-λ)/(γ-1) in the N → ∞ limit when 2 < λ < 3γ being the network degree exponent.
MARKERLESS HUMAN MOTION TRACKING FROM A SINGLE CAMERA USING INTERVAL PARTICLE FILTERING
Authors: SABOUNE JAMAL , CHARPILLET FRANÇOIS
Published: September 2007

In this paper we present a new approach for marker less human motion capture from conventional camera feeds. The aim of our study is to recover 3D positions of key points of the body that can serve for gait analysis. Our approach is based on foreground extraction, an articulated body model and particle filters. In order to be generic and simple, no restrictive dynamic modeling was used. A new modified particle-filtering algorithm was introduced. It is used efficiently to search the model configurations space. This new algorithm, which we call Interval Particle Filtering, reorganizes the configurations search space in an optimal deterministic way and proved to be efficient in tracking natural human movement. Results for human motion capture from a single camera are presented and compared to results obtained from a marker based system. The system proved to be able to track motion successfully even in partial occlusions and even outdoors.
DECOMPOSITIONS OF THE FREE PRODUCT OF GRAPHS
Authors: ACCARDI LUIGI , LENCZEWSKI ROMUALD , SAŁAPATA RAFAŁ
Published: September 2007

We study the free product of rooted graphs and its various decompositions using quantum probabilistic methods. We show that the free product of rooted graphs is canonically associated with free independence, which completes the proof of the conjecture that there exists a product of rooted graphs canonically associated with each notion of noncommutative independence which arises in the axiomatic theory. Using the orthogonal product of rooted graphs, we decompose the branches of the free product of rooted graphs as "alternating orthogonal products". This leads to alternating decompositions of the free product itself, with the star product or the comb product followed by orthogonal products. These decompositions correspond to the recently studied decompositions of the free additive convolution of probability measures in terms of boolean and orthogonal convolutions, or monotone and orthogonal convolutions. We also introduce a new type of quantum decomposition of the free product of graphs, where the distance partition of the set of vertices is taken with respect to a set of vertices instead of a single vertex. We show that even in the case of widely studied graphs this yields new and more complete information on their spectral properties, like spectral measures of a (usually infinite) set of cyclic vectors under the action of the adjacency matrix.
GENERATORS OF DETAILED BALANCE QUANTUM MARKOV SEMIGROUPS
Authors: FAGNOLA FRANCO , UMANITÀ VERONICA
Published: September 2007

For a quantum Markov semigroup [Formula: see text] on the algebra [Formula: see text] with a faithful invariant state ρ, we can define an adjoint [Formula: see text] with respect to the scalar product determined by ρ. In this paper, we solve the open problems of characterizing adjoints [Formula: see text] that are also a quantum Markov semigroup and satisfy the detailed balance condition in terms of the operators H, Lk in the Gorini–Kossakowski–Sudarshan–Lindblad representation [Formula: see text] of the generator of [Formula: see text]. We study the adjoint semigroup with respect to both scalar products 〈a, b〉 = tr (ρa*b) and 〈a, b〉 = tr (ρ1/2a*ρ1/2 b).
RANDOM FIELDS: NON-ANTICIPATING DERIVATIVE AND DIFFERENTIATION FORMULAS
Authors: DI NUNNO GIULIA
Published: September 2007

The non-anticipating stochastic derivative represents the integrand in the best L2-approximation for random variables by Itô non-anticipating integrals with respect to a general stochastic measure with independent values on a space–time product. In this paper some explicit formulas for this derivative are obtained.
Human Impacts in Pine Forests: Past, Present, and Future
Authors: Richardson David M. , Rundel Philip W. , Jackson Stephen T. , Teskey Robert O. , Aronson James , Bytnerowicz Andrzej , Wingfield Michael J. , Procheş Şerban
Published: September 2007

Pines (genus Pinus) form the dominant tree cover over large parts of the Northern Hemisphere. Human activities have affected the distribution, composition, and structure of pine forests for millennia. Different human-mediated factors have affected different pine species in different ways in different regions. The most important factors affecting pine forests are altered fire regimes, altered grazing/browsing regimes, various harvesting/construction activities, land clearance and abandonment, purposeful planting and other manipulations of natural ecosystems, alteration of biotas through species reshuffling, and pollution. These changes are occurring against a backdrop of natural and anthropogenically driven climate change. We review past and current influence of humans in pine forests, seeking broad generalizations. These insights are combined with perspectives from paleoecology to suggest probable trajectories in the face of escalating human pressure. The immense scale of impacts and the complex synergies between agents of change calls for urgent and multifaceted action.
Roles and Effects of Environmental Carbon Dioxide in Insect Life
Authors: Guerenstein Pablo G. , Hildebrand John G.
Published: September 2007

Carbon dioxide (CO2) is a ubiquitous sensory cue that plays multiple roles in insect behavior. In recent years understanding of the well-known role of CO2in foraging by hematophagous insects (e.g., mosquitoes) has grown, and research on the roles of CO2cues in the foraging and oviposition behavior of phytophagous insects and in behavior of social insects has stimulated interest in this area of insect sensory biology. This review considers those advances, as well as some of the mechanistic bases of the modulation of behavior by CO2and important progress in our understanding of the detection and CNS processing of CO2information in insects. Finally, this review briefly addresses how the ongoing increase in atmospheric CO2levels may affect insect life.
Induction of group VIA phospholipase A2activity during in vitro ischemia in C2C12 myotubes is associated with changes in the level of its splice variants
Authors: Poulsen K. A. , Pedersen S. F. , Kolko M. , Lambert I. H.
Published: September 2007

The involvement of group VI Ca2+-independent PLA2s (iPLA2-VI) in in vitro ischemia [oxygen and glucose deprivation (OGD)] in mouse C2C12 myotubes was investigated. OGD induced a time-dependent (0–6 h) increase in bromoenol lactone (BEL)-sensitive iPLA2activity, which was suppressed by specific short interfering (si)RNA knockdown of iPLA2-VIA. OGD was associated with an increase in iPLA2-VIA protein levels, whereas mRNA levels were unchanged. The levels of iPLA2-VIB mRNA and protein were not increased by OGD. RT-PCR and Western blot analysis identified a mouse iPLA2-VIA homolog to catalytically inactive 50-kDa iPLA2-VIA-ankyrin variants previously identified in humans. Both the mRNA and protein levels of this ∼50-kDa variant were reduced significantly within 1 h following OGD. In C2C12 myoblasts, iPLA2-VIA seemed to predominantly reside at the endoplasmatic reticulum, where it accumulated further during OGD. A time-dependent reduction in cell viability during the early OGD period (3 h) was partially prevented by iPLA2-VIA knockdown or pharmacological inhibition (10 μM BEL), whereas iPLA2-VIA overexpression had no effect on cell viability. Taken together, these data demonstrate that OGD in C2C12 myotubes is associated with an increase in iPLA2-VIA activity that decreases cell viability. iPLA2-VIA activation may be modulated by changes in the levels of active and inactive iPLA2-VIA isoforms.
CD36 gene deletion reduces fat preference and intake but not post-oral fat conditioning in mice
Authors: Sclafani A. , Ackroff K. , Abumrad N. A.
Published: September 2007

Several findings suggest the existence of a “fatty” taste, and the CD36 fatty acid translocase is a candidate taste receptor. The present study compared fat preference and acceptance in CD36 knockout (KO) and wild-type (WT) mice using nutritive (triglyceride and fatty acid) and nonnutritive (Sefa Soyate oil) emulsions. In two-bottle tests (24 h/day) naive KO mice, unlike WT mice, displayed little or no preference for dilute soybean oil, linoleic acid, or Sefa Soyate emulsions. At high concentrations (2.5–20%), KO mice developed significant soybean oil preferences, although they consumed less oil than WT mice. The postoral actions of fat likely conditioned these preferences. KO mice, like WT mice, learned to prefer a flavored solution paired with intragastric soybean oil infusions. These findings support CD36 mediation of a gustatory component to fat preference but demonstrate that it is not essential for fat-conditioned flavor preferences. The finding that oil-naive KO mice failed to prefer a nonnutritive oil, assumed to provide texture rather than taste cues, requires explanation. Finally, CD36 deletion decreased fat consumption and enhanced the ability of the mice to compensate for the calories provided by their optional fat intake.
Mitochondrial metabolism during daily torpor in the dwarf Siberian hamster: role of active regulated changes and passive thermal effects
Authors: Brown Jason C. L. , Gerson Alexander R. , Staples James F.
Published: September 2007

During daily torpor in the dwarf Siberian hamster, Phodopus sungorus, metabolic rate is reduced by 65% compared with the basal rate, but the mechanisms involved are contentious. We examined liver mitochondrial respiration to determine the possible role of active regulated changes and passive thermal effects in the reduction of metabolic rate. When assayed at 37°C, state 3 (phosphorylating) respiration, but not state 4 (nonphosphorylating) respiration, was significantly lower during torpor compared with normothermia, suggesting that active regulated changes occur during daily torpor. Using top-down elasticity analysis, we determined that these active changes in torpor included a reduced substrate oxidation capacity and an increased proton conductance of the inner mitochondrial membrane. At 15°C, mitochondrial respiration was at least 75% lower than at 37°C, but there was no difference between normothermia and torpor. This implies that the active regulated changes are likely more important for reducing respiration at high temperatures (i.e., during entrance) and/or have effects other than reducing respiration at low temperatures. The decrease in respiration from 37°C to 15°C resulted predominantly from a considerable reduction of substrate oxidation capacity in both torpid and normothermic animals. Temperature-dependent changes in proton leak and phosphorylation kinetics depended on metabolic state; proton leakiness increased in torpid animals but decreased in normothermic animals, whereas phosphorylation activity decreased in torpid animals but increased in normothermic animals. Overall, we have shown that both active and passive changes to oxidative phosphorylation occur during daily torpor in this species, contributing to reduced metabolic rate.
A transfer function method for the continuous assessment of baroreflex control of renal sympathetic nerve activity in rats
Authors: Kanbar Roy , Oréa Valérie , Chapuis Bruno , Barrès Christian , Julien Claude
Published: September 2007

The present study examined whether the gain of the transfer function relating cardiac-related rhythm of renal sympathetic nerve activity (RSNA) to arterial pressure (AP) pulse might serve as a spontaneous index of sympathetic baroreflex sensitivity (BRS). AP and RSNA were simultaneously recorded in conscious rats, either baroreceptor-intact (control, n = 11) or with partial denervation of baroreflex afferents [aortic baroreceptor denervated (ABD; n = 10)] during 1-h periods of spontaneous activity. Transfer gain was calculated over 58 adjacent 61.4-s periods (segmented into 10.2-s periods). Coherence between AP and RSNA was statistically ( P < 0.05) significant in 90 ± 3% and 56 ± 10% of cases in control and ABD rats, respectively. Transfer gain was higher ( P = 0.0049) in control [2.39 ± 0.13 normalized units (NU)/mmHg] than in ABD (1.48 ± 0.22 NU/mmHg) rats. In the pooled study sample, transfer gain correlated with sympathetic BRS estimated by the vasoactive drug injection technique ( R = 0.75; P < 0.0001) and was inversely related to both time- (standard deviation; R = −0.74; P = 0.0001) and frequency-domain [total spectral power (0.00028–2.5 Hz); R = −0.82; P < 0.0001] indices of AP variability. In control rats, transfer gain exhibited large fluctuations (coefficient of variation: 34 ± 3%) that were not consistently related to changes in the mean level of AP, heart rate, or RSNA. In conclusion, the transfer function method provides a continuous, functionally relevant index of sympathetic BRS and reveals that the latter fluctuates widely over time.
Renal and cardiac neuropeptide Y and NPY receptors in a rat model of congestive heart failure
Authors: Callanan Ean Y. , Lee Edward W. , Tilan Jason U. , Winaver Joseph , Haramati Aviad , Mulroney Susan E. , Zukowska Zofia
Published: September 2007

Neuropeptide Y (NPY) is coreleased with norepinephrine and stimulates vasoconstriction, vascular and cardiomyocyte hypertrophy via Y1 receptors (R) and angiogenesis via Y2R. Although circulating NPY is elevated in heart failure, NPY's role remains unclear. Activation of the NPY system was determined in Wistar rats with the aortocaval (A-V) fistula model of high-output heart failure. Plasma NPY levels were elevated in A-V fistula animals (115.7 ± 15.3 vs. 63.1 ± 17.4 pM in sham, P < 0.04). Animals either compensated [urinary Na+excretion returning to normal with moderate disease (COMP)] or remained decompensated with severe cardiac and renal failure (urinary Na+excretion <0.5 meq/day), increased heart weight, decreased mean arterial pressure and renal blood flow (RBF), and death within 5–7 days (DECOMP). Cardiac and renal tissue NPY decreased with heart failure, proportionate to the severity of renal complications. Cardiac and renal Y1R mRNA expression also decreased (1.5-fold, P < 0.005) in rats with heart failure. In contrast, Y2R expression increased up to 72-fold in the heart and 5.7-fold in the kidney ( P < 0.001) proportionate to severity of heart failure and cardiac hypertrophy. Changes in receptor expression were confirmed since the Y1R agonist, [Leu31, Pro34]-NPY, had no effect on RBF, whereas the Y2R agonist (13–36)-NPY increased RBF to compensate for disease. Thus, in this model of heart failure, cardiac and renal NPY Y1 receptors decrease and Y2 receptors increase, suggesting an increased effect of NPY on the receptors involved in cardiac remodeling and angiogenesis, and highlighting an important regulatory role of NPY in congestive heart failure.
Aldosterone-induced increases in superoxide production counters nitric oxide inhibition of epithelial Na channel activity in A6 distal nephron cells
Authors: Yu Ling , Bao Hui-Fang , Self Julie L. , Eaton Douglas C. , Helms My N.
Published: September 2007

Oxygen radicals play an important role in signal transduction and have been shown to influence epithelial sodium channel (ENaC) activity. We show that aldosterone, the principal hormone regulating renal ENaC activity, increases superoxide (O2−) production in A6 distal nephron cells. Aldosterone (50 nM to 1.5 μM) induced increases in dihydroethidium fluorescence in a dose-dependent manner in confluent A6 epithelial cells. Using single-channel measurements, we showed that sequestering endogenous O2−(with the O2−scavenger 2,2,6,6-tetramethylpiperidine 1-oxyl) significantly decreased ENaC open probability from 0.10 ± 0.03 to 0.03 ± 0.01. We also found that increasing endogenous O2−in A6 cells, by applying a superoxide dismutase inhibitor, prevented nitric oxide (NO) inhibition of ENaC activity. ENaC open probability values did not significantly change from control values (0.23 ± 0.05) after superoxide dismutase and 1.5 μM NO coincubation (0.21 ± 0.04). We report that xanthine oxidase and hypoxanthine compounds increase local concentrations of O2−by ∼30%; with this mix, an increase in ENaC number of channels times the open probability (from 0.1 to 0.3) can be achieved in a cell-attached patch. Our data also suggest that O2−alters NO activity in a cGMP-independent mechanism, since pretreating A6 cells with ODQ compound (a selective inhibitor of NO-sensitive guanylyl cyclase) failed to block 2,2,6,6-tetramethylpiperidine 1-oxyl inhibition of ENaC activity.
Susceptibility to HSV-1 infection and exercise stress in female mice: role of estrogen
Authors: Brown A. S. , Davis J. M. , Murphy E. A. , Carmichael M. D. , Carson J. A. , Ghaffar A. , Mayer E. P.
Published: September 2007

Exhaustive exercise has been associated with an increased risk for upper respiratory tract infections in mice and humans. We have previously shown (Brown AS, Davis JM, Murphy AE, Carmichael MD, Ghaffer A, Mayer EP. Med Sci Sports Exerc 36: 1290–1295, 2004) that female mice are better protected from the lethal effects of herpes simplex virus type 1 (HSV-1) infection, both at rest and following exercise stress, but little is known about possible mechanisms. This study tested the effects of estrogen on HSV-1 infection and macrophage antiviral resistance following repeated exhaustive exercise. Female mice were assigned to either exercise (Ex) or control (C): intact female (I-C or I-Ex), ovariectomized female (O-C or O-Ex), or ovariectomized estrogen-supplemented female (E-C or E-Ex). Exercise consisted of treadmill running to volitional fatigue (∼125 min) for 3 consecutive days. Intact female mice had a later time to death than O and E ( P < 0.05) and fewer deaths than both O and E ( P < 0.05). Exercise stress was associated with increased time to sickness ( P < 0.05) and symptom severity at days 6 and 12–21 postinfection ( P < 0.05) and decreased macrophage antiviral resistance ( P < 0.001) in all groups. E had increased symptom severity at days 6 and 13–21 postinfection ( P < 0.05). Results indicate that intact female mice are better protected from the lethal effects of HSV-1 infection and that exercise stress had a similar negative impact in all groups. This protective effect was lost in ovariectomized mice, but it was not reinstated by 17β-estradiol replacement. This indicates that other ovarian factors, alone or in combination with estrogen, are responsible for the protective effects in females.
Horizontal Smooth Pursuit Adaptation in Macaques After Muscimol Inactivation of the Dorsolateral Pontine Nucleus (DLPN)
Authors: Ono Seiji , Mustari Michael J.
Published: September 2007

The smooth pursuit (SP) system can adapt its response to developmental changes, injury, and behavioral context. Previous lesion and single-unit recording studies show that the macaque cerebellum plays a role in SP initiation, maintenance, and adaptation. The aim of this study was to determine the potential role of the DLPN in SP adaptation. The DLPN receives inputs from the cortical SP system and delivers eye and visual motion information to the dorsal/ventral paraflocculus and vermis of the cerebellum. We studied SP adaptation in two juvenile rhesus monkeys ( Macaca mulatta), using double steps of target speed that step- up (10–30°/s) or step-down (25–5°/s). We used microinjection of muscimol (≤2%; 0.15 μl) to reversibly inactivate the DLPN, unilaterally. After DLPN inactivation, initial ipsilesional SP acceleration (first 100 ms) was significantly reduced by 47–74% ( P < 0.01; unpaired t-test) of control values in the single-speed step-ramp paradigm. Similarly, ipsilesional steady-state SP velocity was also reduced by 59–78% ( P < 0.01; unpaired t-test) of control values. Contralesional SP was not impaired after DLPN inactivation. Control testing showed significant adaptive changes of initial SP eye acceleration after 100 trials in either step-up or step-down paradigms. After inactivation, during ipsilesional SP, adaptation was impaired in the step-up but not in the step-down paradigm. In contrast, during contralesional tracking, adaptive capability remained in the step-down but not in the step-up paradigm. Therefore SP adaptation could depend, in part, on direction sensitive eye/visual motion information provided by DLPN neurons to cerebellum.
Regulation of the Crab Heartbeat by FMRFamide-Like Peptides: Multiple Interacting Effects on Center and Periphery
Authors: Fort Timothy J. , Brezina Vladimir , Miller Mark W.
Published: September 2007

We are studying the functional “logic” of neuromodulatory actions in a simple central pattern generator (CPG)-effector system, the heart of the blue crab Callinectes sapidus. The rhythmic contractions of this heart are neurogenic, driven by rhythmic motor patterns generated by the cardiac ganglion (CG). Here we used anatomical and physiological methods to examine the sources and actions on the system of the FMRFamide-like peptides (FLPs) TNRNFLRFamide (F1), SDRNFLRFamide (F2), and GYNRSFLRFamide, an authentic Callinectes FLP. Immunohistochemical localization revealed a plexus of FLP-immunoreactive fibers in the pericardial organs (POs), from which modulators are released to reach the heart as circulating neurohormones. Combined backfill and immunohistochemical experiments indicated that the FLPs in the POs originated in the CNS, from large neurosecretory cells in the B cluster of the first thoracic neuromere. In physiological experiments, we examined the actions of the FLPs on the intact working heart, on the semi-intact heart in which we could record the motor patterns as well as the muscle contractions, on the isolated CG, and in a preparation developed to assess direct actions on the muscle with controlled patterns of motor neuron spikes. The FLPs had strong positive chronotropic and inotropic effects. Dissection of these effects suggested that they were produced through at least two primary actions of the FLPs exerted both on the heart muscle and on the CG. These primary actions elicited numerous secondary consequences mediated by the feedforward and feedback interactions that integrate the activity of the complete, coupled CPG-effector system.
Corticofugal Modulation of Multi-Parametric Auditory Selectivity in the Midbrain of the Big Brown Bat
Authors: Zhou Xiaoming , Jen Philip H.-S.
Published: September 2007

Corticofugal modulation of sub-cortical auditory selectivity has been shown previously in mammals for frequency, amplitude, time, and direction domains in separate studies. As such, these studies do not show if multi-parametric corticofugal modulation can be mediated through the same sub-cortical neuron. Here we specifically studied corticofugal modulation of best frequency (BF), best amplitude (BA), and best azimuth (BAZ) at the same neuron in the inferior colliculus of the big brown bat, Eptesicus fuscus, using focal electrical stimulation in the auditory cortex. Among 53 corticofugally inhibited collicular neurons examined, cortical electrical stimulation produced a shift of all three measurements (i.e., BF, BA, and BAZ) toward the value of stimulated cortical neuron in 13 (24.5%) neurons, two measurements (i.e., BF and BAZ or BA and BAZ) in 19 (36%) neurons, and one measurement in 16 (30%) neurons. Cortical electrical stimulation did not shift any of these measurements in the remaining five (9.5%) neurons. Corticofugally induced collicular BF shift was symmetrical, whereas the shift in collicular BA or BAZ was asymmetrical. The amount of shift in each measurement was significantly correlated with each measurement difference between recorded collicular and stimulated cortical neurons. However, shifts of three measurements were not correlated with each other. Furthermore, average measurement difference between collicular and cortical neurons was larger for collicular neurons with measurement shifts than for those without shifts. These data indicate that multi-parametric corticofugal modulation can be mediated through the same subcortical neuron based on the difference in auditory selectivity between subcortical and cortical neurons.