bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing Mental Health Concerns in Schools: Does School-Link Achieve Its Aims?
Authors: Maloney Danielle , Jones Judith , Walter Garry , Davenport Rita
Published: January 2008

Objective: The aim of this paper was to evaluate the reach and impact of the New South Wales' School-Link initiative.

Method: Postal surveys, focus groups and interviews were conducted.

Results: School-Link has established a strong partnership between health and education, raised the awareness of child and adolescent mental health problems and contributed in the areas of prevention and early intervention.

Conclusions: Building on the momentum and the foundations that have been established is the next challenge for this initiative.
Putting ‘Addiction’ Back Into Psychiatry: The RANZCP Section of Addiction Psychiatry
Authors: Lubman Dan , Jurd Stephen , Baigent Michael , Krabman Peter
Published: January 2008

Objective: The aim of this paper is to provide an overview of the history and activities of the RANZCP Section of Addiction Psychiatry, as well as its current challenges and opportunities.

Conclusions: From initial exclusion to an active and growing membership, the Section of Addiction Psychiatry continues to ensure that problematic substance use and gambling remain core issues within Australasian psychiatry. In addition to commenting and contributing to ongoing clinical and policy initiatives, the Section has recently introduced an advanced training curriculum and maintains a strong partnership with the relatively new Australasian Chapter of Addiction Medicine. Its active input into education, training, media and policy development within the College guarantees that psychiatry is represented within the addiction field, and that tomorrow's psychiatrists are competent to assess and treat comorbid addiction issues.
Developing the ‘Youth Model’ in Mental Health Services
Authors: Birleson Peter , Vance Alasdair
Published: January 2008

Objective: The aim of this paper was to review the basis of the ‘youth model’ and new ‘headspace’ service delivery structures, proposed as a solution to the problem of high rates of psychiatric disorder in the youth period of life. Several issues were examined through asking key questions and answering these from the perspective of two academically oriented child and adolescent psychiatrists.

Conclusions: As half of all mental disorders appear during childhood and early adolescence, more research into the origin and emergence of these problems should focus on this early period of life. Prevention research should also focus largely on children and adolescents, with interventions targeted through sequential assessment at pivotal stages. The current problem of access to mental health care for youth in the adult mental health service system could be improved with additional funding and culture change – it is not necessary to create a new service system. Indeed, there are dangers in establishing new services for 12–25-year-olds, as the 12–17-year-old population has different needs from 18–25-year-olds. In particular, the younger group are at risk of ‘adultification’ by being grouped together with young adults, and this risk needs to be actively managed. Health service planning must pay attention to developmental differences. Several suggestions are proposed for addressing the mental health needs of young adults.
Patient Satisfaction with the Black Dog Institute Depression Clinic
Authors: Fletcher Kathryn , Parker Gordon , Tully Lucy
Published: January 2008

Objective: The aim of this paper is to report on patient satisfaction with the Black Dog Institute Depression Clinic, a tertiary referral service providing assessment and treatment advice to patients with mood disorders.

Method: Patients who attended the Depression Clinic over the period 2006–2007 received questionnaires in the mail assessing satisfaction with the services received. Of the 321 patients attending, 114 (35%) replied. Results from 110 patients were subsequently analysed.

Results: Overall, patients were very satisfied with the services received. However, a number of priority areas were identified including provision of information about diagnosis, causal factors and treatment options; managing patient expectations about services offered; the need for improvement of communication between patient and psychiatrist; and the need for adequate de-briefing for those who receive an unexpected or differing diagnosis.

Conclusions: Patient satisfaction is a central component in shaping clinical service development to ensure delivery of effective health care. Findings from this study have implications for the improved delivery of psychiatric services.
Impact of Severe Acute Respiratory Syndrome and the Perceived Avian Influenza Epidemic on the Increased Rate of Influenza Vaccination Among Nurses in Hong Kong
Authors: Tam Dennise K. P. , Lee Shui-Shan , Lee Sing
Published: January 2008

Objective.

To determine the rate of influenza vaccination and the factors associated with the vaccination's acceptance among nurses in Hong Kong.

Design.

Cross-sectional survey.

Participants.

Nurses practicing between 2003 and 2007.

Methods.

A questionnaire was sent to all nurses registered with any of the 3 nursing associations that participated in this study.

Results.

A total of 941 completed questionnaires were available for analysis, though not all nurses responded to every question (response rate, 33.5%-36.3%). Vaccination rates in 2006 and 2007 were 57.2% and 46.2%, respectively. Nurses who were vaccinated in 2006 were more likely to get vaccinated in 2007 (P<.01); 56% of the nurses perceived influenza vaccine as being effective against influenza. The perceived effectiveness of influenza vaccine was a consistent predictor of rates of vaccination in 2006 (odds ratio [OR], 8.47 [95% confidence interval {CI}, 6.13-11.70];P<.01) and 2007 (OR, 6.05 [95% CI, 3.79-9.67];P<.01). Concern about contracting avian influenza was a predictor of the vaccination rate in 2006 but not in 2007 (OR, 1.47 [95% CI, 1.03-2.09];P<.05), as was the perceived lack of control over avian influenza infection (OR, 1.52 [95% CI, 1.06-2.18];P<.05).

Conclusions.

The overall influenza vaccination rate for nurses in Hong Kong was about 50%. It was affected by the perceived threat of an impending outbreak. The attitudes of nurses toward the effectiveness of and rationale for vaccination were a major barrier to increasing the rate of vaccination.
Nosocomial Dermatitis Caused by Dermanyssus gallinae
Authors: Bellanger A. P. , Bories C. , Foulet F. , Bretagne S. , Botterel F.
Published: January 2008

The mite Dermanyssus gallinae may cause pruritic dermatitis in humans. We describe a case of nosocomial infestation with D. gallinae from an abandoned pigeon nest suspended on the front wall of the Hôpital Henri Mondor near a window. Close surveillance and regular destruction of pigeon nests could prevent these incidents of infection in humans.
QTLNetwork: mapping and visualizing genetic architecture of complex traits in experimental populations
Authors: Yang Jian , Hu Chengcheng , Hu Han , Yu Rongdong , Xia Zhen , Ye Xiuzi , Zhu Jun
Published: January 2008

Summary: QTLNetwork is a software package for mapping and visualizing the genetic architecture underlying complex traits for experimental populations derived from a cross between two inbred lines. It can simultaneously map quantitative trait loci (QTL) with individual effects, epistasis and QTL–environment interaction. Currently, it is able to handle data from F2, backcross, recombinant inbred lines and double-haploid populations, as well as populations from specific mating designs (immortalized F2 and BCnFn populations). The Windows version of QTLNetwork was developed with a graphical user interface. Alternatively, the command-line versions have the facility to be run in other prevalent operating systems, such as Linux, Unix and MacOS.

Availability:  http://ibi.zju.edu.cn/software/qtlnetwork

Contact:  jzhu@zju.edu.cn
Figaro: a novel statistical method for vector sequence removal
Authors: White James Robert , Roberts Michael , Yorke James A. , Pop Mihai
Published: January 2008

Motivation: Sequences produced by automated Sanger sequencing machines frequently contain fragments of the cloning vector on their ends. Software tools currently available for identifying and removing the vector sequence require knowledge of the vector sequence, specific splice sites and any adapter sequences used in the experiment—information often omitted from public databases. Furthermore, the clipping coordinates themselves are missing or incorrectly reported. As an example, within the ∼1.24 billion shotgun sequences deposited in the NCBI Trace Archive, as many as ∼735 million (∼60%) lack vector clipping information. Correct clipping information is essential to scientists attempting to validate, improve and even finish the increasingly large number of genomes released at a ‘draft’ quality level.

Results: We present here Figaro, a novel software tool for identifying and removing the vector from raw sequence data without prior knowledge of the vector sequence. The vector sequence is automatically inferred by analyzing the frequency of occurrence of short oligo-nucleotides using Poisson statistics. We show that Figaro achieves 99.98% sensitivity when tested on ∼1.5 million shotgun reads from Drosophila pseudoobscura. We further explore the impact of accurate vector trimming on the quality of whole-genome assemblies by re-assembling two bacterial genomes from shotgun sequences deposited in the Trace Archive. Designed as a module in large computational pipelines, Figaro is fast, lightweight and flexible.

Availability: Figaro is released under an open-source license through the AMOS package (http://amos.sourceforge.net/Figaro).

Contact:  mpop@umiacs.umd.edu
Charge-density studies of energetic materials: CL-20 and FOX-7
Authors: Meents A. , Dittrich B. , Johnas S. K. J. , Thome V. , Weckert E. F.
Published: January 2008

Experimental electron densities and derived properties have been determined for the two energetic materials CL-20 (3,5,9,11-tetraacetyl-14-oxo-1,3,5,7,9,11-hexaazapentacyclo-[5.5.3.02,6.04,10.08,12]pentadecane), and FOX-7 (1,1-diamino-2,2-dinitroethylene) from single-crystal diffraction. Synchrotron data extending to high scattering angles were measured at low temperature. Low figures-of-merit and excellent residuals were obtained. The Hansen & Coppens multipole-model electron density was compared with results from theoretical calculations via structure factors simulating an experiment. Chemical bonding in the molecules is discussed and a topological analysis gives insight especially into the character of those bonds that are thought to play a key role in the decomposition of the molecules. A comparison of theoretical and experimental electrostatic potentials shows no obvious evidence supporting earlier findings on other nitroheterocyclic molecules that electron-density maxima near the C—NO2 bonds mapped on the electron-density isosurface can be correlated with impact sensitivities. For FOX-7 periodic Hartree–Fock calculations were performed to investigate the influence of the crystal field on the electron density distribution.
Predicting regularities in lattice constants of GdFeO3-type perovskites
Authors: Khan Asifullah , Javed Syed Gibran
Published: January 2008

A novel idea of employing genetic programming to obtain mathematical expressions representing the dependency of lattice constants (LC) on their atomic parameters is presented in this paper. The results obtained from simulations reveal that only two atomic parameters are sufficient for LC prediction of GdFeO3-type perovskites. In addition, an advantage of this approach is that there is no need to save any trained model as in the case of other existing machine-learning based approaches.
Disorder in Ag7GeSe5I, a superionic conductor: temperature-dependent anharmonic structural study
Authors: Albert Stéphanie , Pillet Sébastien , Lecomte Claude , Pradel Annie , Ribes Michel
Published: January 2008

A temperature-dependent structural investigation of the substituted argyrodite Ag7GeSe5I has been carried out on a single crystal from 15 to 475 K, in steps of 50 K, and correlated to its conductivity properties. The argyrodite crystallizes in a cubic cell with the F\bar 43m space group. The crystal structure exhibits high static and dynamic disorder which has been efficiently accounted for using a combination of (i) Gram–Charlier development of the Debye–Waller factors for iodine and silver, and (ii) a split-atom model for Ag+ ions. An increased delocalization of the mobile d
10 Ag+ cations with temperature has been clearly shown by the inspection of the joint probability-density functions; the corresponding diffusion pathways have been determined.
Structures of the cubic and rhombohedral high-pressure modifications of silicon as packing of the rod-like substructures determined by the algebraic geometry
Authors: Kraposhin V. S. , Talis A. L. , Kosushkin V. G. , Ogneva A. A. , Zinober L. I.
Published: January 2008

Tessellations by generating clusters are proposed for the high-pressure phases BC8 and R8 of silicon. The structures of both high-pressure phases are represented by the parallel packings of rods. The latter are stacks of distorted icosahedra, joined by a common triangular face and flattened out along the threefold symmetry axis. Along the rod axis there is an alternation of empty and double-centered icosahedra. The empty icosahedra are additionally distorted in the cubic BC8 phase by antiparallel rotation about the rod axis, while the double-centered icosahedra are distorted by that rotation in the rhombohedral R8 phase. A possible mechanism of the reversible BC8 ↔ R8 transformation is proposed as the rotation about the rod axis of the common triangular face of the neighboring icosahedra, thus transforming between distorted and undistorted icosahedra. The graphs of the generating clusters for both the BC8 and R8 structures are determined by two subconfigurations of the same construction of the finite projective geometry.
Normal hypertrophy accompanied by phosphoryation and activation of AMP‐activated protein kinase α1 following overload in LKB1 knockout mice
Authors: McGee Sean L. , Mustard Kirsty J. , Hardie D. Grahame , Baar Keith
Published: January 2008

The activation of the AMP‐activated protein kinase (AMPK) and inhibition of the mammalian target of rapamycin complex 1 (mTORC1) is hypothesized to underlie the fact that muscle growth following resistance exercise is decreased by concurrent endurance exercise. To directly test this hypothesis, the capacity for muscle growth was determined in mice lacking the primary upstream kinase for AMPK in skeletal muscle, LKB1. Following either 1 or 4 weeks of overload, there was no difference in muscle growth between the wild type (wt) and LKB1−/− mice (1 week: wt, 38.8 ± 7.75%; LKB1−/−, 27.8 ± 12.98%; 4 week: wt, 75.8 ± 15.2%; LKB1−/−, 85.0 ± 22.6%). In spite of the fact that the LKB1 had been knocked out in skeletal muscle, the phosphorylation and activity of the α1 isoform of AMPK were markedly increased in both the wt and the LKB1−/− mice. To identify the upstream kinase(s) responsible, we studied potential upstream kinases other than LKB1. The activity of both Ca2+–calmodulin‐dependent protein kinase kinase α(CaMKKα) (5.05 ± 0.86‐fold) and CaMKKβ (10.1 ± 2.59‐fold) increased in the overloaded muscles, and this correlated with their increased expression. Phosphorylation of TAK‐1 also increased 10‐fold following overload in both the wt and LKB1 mice. Even though the α1 isoform of AMPK was activated by overload, there were no increases in expression of mitochondrial proteins or GLUT4, indicating that the α1 isoform is not involved in these metabolic adaptations. The phosphorylation of TSC2, an upstream regulator of the TORC1 pathway, at the AMPK site (Ser1345) was increased in response to overload, and this was not affected by LKB1 deficiency. Taken together, these data suggest that the α1 isoform of AMPK is preferentially activated in skeletal muscle following overload in the absence of metabolic adaptations, suggesting that this isoform might be important in the regulation of growth but not metabolism.
Up‐regulation of hypertonicity‐activated myo‐inositol transporter SMIT1 by the cell volume‐sensitive protein kinase SGK1
Authors: Klaus F. , Palmada M. , Lindner R. , Laufer J. , Jeyaraj S. , Lang F. , Boehmer C.
Published: January 2008

Mechanisms of regulatory cell volume increase following cell shrinkage include accumulation of organic osmolytes such as betaine, taurine, sorbitol, glycerophosphorylcholine (GPC) and myo‐inositol. Myo‐inositol is taken up by the sodium‐myo‐inositol‐transporter SMIT1 (SLC5A3) expressed in a wide variety of cell types. Hypertonicity induces the transcription of the SMIT1 gene upon binding of the transcription factor tonicity enhancer binding protein (TonEBP) to tonicity responsive enhancers (TonE) in the SMIT1 promoter region. However, little is known about post‐translational regulation of the carrier protein. In this study we show that SMIT1 is modulated by the serum‐ and glucocorticoid‐inducible kinase SGK1, a protein genomically up‐regulated by hypertonicity. As demonstrated by two‐electrode voltage‐clamp in the Xenopus oocyte expression system, SMIT1‐mediated myo‐inositol‐induced currents are up‐regulated by coexpression of wild type SGK1 and constitutively active S422DSGK1 but not by inactive K127NSGK1. The increase in SMIT1 activity is due to an elevated cell surface expression of the carrier while its kinetic properties remain unaffected. According to the decay of SMIT1 activity in the presence of brefeldin A, SGK1 stabilizes the SMIT1 protein in the plasma membrane. The SGK isoforms SGK2, SGK3 and the closely related protein kinase B (PKB) are similarly capable of activating SMIT1 activity. SMIT1‐mediated currents are decreased by coexpression of the ubiquitin‐ligase Nedd4‐2, an effect counteracted by additional coexpression of SGK1. In conclusion, the present observations disclose SGK isoforms and protein kinase B as novel regulators of SMIT1 activity.
Muscle synergies during locomotion in the cat: a model for motor cortex control
Authors: Drew Trevor , Kalaska John , Krouchev Nedialko
Published: January 2008

It is well established that the motor cortex makes an important contribution to the control of visually guided gait modifications, such as those required to step over an obstacle. However, it is less clear how the descending cortical signal interacts with the interneuronal networks in the spinal cord to ensure that precise changes in limb trajectory are appropriately incorporated into the base locomotor rhythm. Here we suggest that subpopulations of motor cortical neurones, active sequentially during the step cycle, may regulate the activity of small groups of synergistic muscles, likewise active sequentially throughout the step cycle. These synergies, identified by a novel associative cluster analysis, are defined by periods of muscle activity that are coextensive with respect to the onset and offset of the EMG activity. Moreover, the synergies are sparse and are frequently composed of muscles acting around more than one joint. During gait modifications, we suggest that subpopulations of motor cortical neurones may modify the magnitude and phase of the EMG activity of all muscles contained within a given synergy. Different limb trajectories would be produced by differentially modifying the activity in each synergy thus providing a flexible substrate for the control of intralimb coordination during locomotion.
Cyclic movement stimulates hyaluronan secretion into the synovial cavity of rabbit joints
Authors: Ingram K. R. , Wann A. K. T. , Angel C. K. , Coleman P. J. , Levick J. R.
Published: January 2008

The novel hypothesis that the secretion of the joint lubricant hyaluronan (HA) is coupled to movement has implications for normal function and osteoarthritis, and was tested in the knee joints of anaesthetized rabbits. After washing out the endogenous synovial fluid HA (miscibility coefficient 0.4), secretion into the joint cavity was measured over 5 h in static joints and in passively cycled joints. The net static secretion rate (11.2 ± 0.7 μg h−1, mean ±s.e.m., n= 90) correlated with the variable endogenous HA mass (mean 367 ± 8 μg), with a normalized value of 3.4 ± 0.2 μg h−1 (100 μg)−1. Cyclic joint movement approximately doubled the net HA secretion rate to 22.6 ± 1.2 μg h−1 (n= 77) and raised the normalized percentage to 5.9 ± 0.3 μg h−1 (100 μg)−1. Secretion was inhibited by 2‐deoxyglucose and iodoacetate, confirming active secretion. The net accumulation rate underestimated true secretion rate due to some trans‐synovial loss. HA turnover time (endogenous mass/secretion rate) was 17–30 h (static) to 8–15 h (moved) The results demonstrate for the first time that the active secretion of HA is coupled to joint usage. Movement–secretion coupling may protect joints against the damaging effects of repetitive joint use, replace HA lost during periods of immobility (overnight), and contribute to the clinical benefit of exercise therapy in moderate osteoarthritis.
Functional α7‐containing nicotinic acetylcholine receptors localize to cell bodies and proximal dendrites in the rat substantia nigra pars reticulata
Authors: Poisik Olga V. , Shen Jian‐xin , Jones Susan , Yakel Jerrel L.
Published: January 2008

The substantia nigra pars reticulata (SNr) is the primary output nucleus for the basal ganglia (BG) in the rat. The SNr is reciprocally connected with the pedunculopontine tegmental nucleus (PPN) in the brainstem, which provides cholinergic innervation to most BG nuclei. The cholinergic input into the BG is considered to be important because PPN activity is altered in Parkinson's disease (PD), a neurological disorder involving the BG, and cholinergic pharmacotherapy is beneficial in alleviating some of its symptoms. In order to better understand the role of cholinergic input to the BG, we examined the effects of nicotinic acetylcholine receptor (nAChR) activation in the GABAergic neurons in slices through juvenile rat SNr. With the aide of subtype selective antagonists, we found that SNr neurons express the α7 subtype of nAChRs, the function of which we assessed using the whole cell patch‐clamp recording technique. Besides α7 nAChRs, GABAergic SNr neurons also contained functional non‐α7 nAChRs. Using local photolysis of caged carbachol, a broad‐spectrum cholinergic agonist, we mapped α7 nAChR‐mediated currents along the visible extent of filled SNr neurons and found that α7 nAChRs can be functionally detected as far as 60 μm away from the soma. Our data are paving the way to a better understanding of the physiological roles of nAChRs in the BG.
Role for metabotropic glutamate receptor 5 (mGluR5) in the pathogenesis of fragile X syndrome
Authors: Dölen Gül , Bear Mark F.
Published: January 2008

Metabotropic glutamate receptors (mGluRs) have been implicated in a diverse variety of neuronal functions. Studies reviewed here indicate that exaggerated signalling through mGluR5 can account for multiple cognitive and syndromic features of fragile X syndrome, the most common inherited form of mental retardation and autism. Since a reduction of mGluR5 signalling can reverse fragile X phenotypes, these studies provide a compelling rationale for the use of mGluR5 antagonists for the treatment of fragile X and related disorders.
Control Design for the Active Stabilization of Rail Wheelsets
Authors: Mei T. X. , Li H.
Published: January 2008

Through a detailed control assessment of a conventional railway wheelset, this paper addresses some of the key design issues in the development of active primary suspensions for the stabilization control of railway vehicles. It reveals the basic feedback requirements for achieving adequate stability and hence provides a useful insight of how active controllers may be structured. For the control design, a number of factors in addition to the stabilization are considered including the actuation requirements, creep forces at the wheel-rail contact, track following as well as robustness against parameter variations. Based on the outcome of the control analysis, the study proposes a design and optimization procedure for the development of active wheelset control. The design method is applied to a two-axle vehicle in a case study, which shows that the new design approach is advantageous when compared with other design methods previously studied.
Disturbance Rejection in the Control of a Maglev Artificial Heart
Authors: Gentili Luca , Marconi Lorenzo , Paden Brad
Published: January 2008

This paper is devoted to the development of an advanced controller for a maglev artificial heart: in particular, a magnetically levitated left ventricular assist device is studied and the disturbances from the natural heart are taken into account. The main goal is to define a control action able to reject dc as well as periodical disturbances from the control input in steady state. This is accomplished by exploiting the intrinsic instability of the system. The paper presents a couple of approaches for solving the problem: an internal model based approach and a solution based on adaptive observers. The internal model based solution relies on the knowledge of the frequencies of the sinusoidal disturbances affecting the system: this hypothesis is not far from the reality of the maglev apparatus as the shape and frequency of the quasiperiodic disturbance can be known with the addition of sensors. The design methodology based on the use of adaptive observers does not require the perfect knowledge of the frequencies of sinusoidal disturbances as an adaptive mechanism is presented to estimate them.
Nondiagonal MIMO QFT Controller Design for Darwin-Type Spacecraft With Large Flimsy Appendages
Authors: Garcia-Sanz Mario , Eguinoa Irene , Barreras Marta , Bennani Samir
Published: January 2008

This paper deals with the design of robust control strategies to govern the position and attitude of a Darwin-type spacecraft with large flexible appendages. The satellite is one of the flyers of a multiple spacecraft constellation for a future ESA mission. It presents a 6×6 high order multiple-input–multiple-output (MIMO) model with large uncertainty and loop interactions introduced by the flexible modes of the low-stiffness appendages. The scientific objectives of the satellite require very demanding control specifications for position and attitude accuracy, high disturbance rejection, loop-coupling attenuation, and low controller order. The paper demonstrates the feasibility of a sequential nondiagonal MIMO quantitative feedback theory (QFT) strategy controlling the Darwin spacecraft and compares the results with H-infinity and sequential diagonal MIMO QFT designs.
Discrete Lagrange Equations for Thermofluid Systems
Authors: Fahrenthold Eric P. , Hean Charles R.
Published: January 2008

A primary focus of the system dynamics literature is the development of structured modeling methods, suitable for application to a diverse array of engineering problems. An important obstacle in the development of unified modeling methods is the need to employ Eulerian reference frames in many thermofluid systems applications. An extension of Lagrange’s equations, to compressible thermofluid dynamics in Eulerian frames, offers a general modeling methodology for thermofluid systems compatible with discrete energy methods widely used for mechanical systems simulations.
Dynamic Image-Based Visual Servo Control Using Centroid and Optic Flow Features
Authors: Mahony R. , Corke P. , Hamel T.
Published: January 2008

This paper considers the question of designing a fully image-based visual servo control for a class of dynamic systems. The work is motivated by the ongoing development of image-based visual servo control of small aerial robotic vehicles. The kinematics and dynamics of a rigid-body dynamical system (such as a vehicle airframe) maneuvering over a flat target plane with observable features are expressed in terms of an un-normalized spherical centroid and an optic flow measurement. The image-plane dynamics with respect to force input are dependent on the height of the camera above the target plane. This dependence is compensated by introducing virtual height dynamics and adaptive estimation in the proposed control. A fully nonlinear adaptive control design is provided that ensures asymptotic stability of the closed-loop system for all feasible initial conditions. The choice of control gains is based on an analysis of the asymptotic dynamics of the system. Results from a realistic simulation are presented that demonstrate the performance of the closed-loop system. To the author’s knowledge, this paper documents the first time that an image-based visual servo control has been proposed for a dynamic system using vision measurement for both position and velocity.
Position Control Using Acceleration-Based Identification and Feedback With Unknown Measurement Bias
Authors: Chandrasekar Jaganath , Bernstein Dennis S.
Published: January 2008

A position-command-following problem for asymptotically stable linear systems is considered. To account for modeling limitations, we assume that a model is not available. Instead, acceleration data are used to construct a compliance (position-output) model, which is subsequently used to design a position servo loop. Furthermore, we assume that the acceleration measurements obtained from inertial sensors are biased. A subspace identification algorithm is used to identify the inertance (acceleration-output) model, and the biased acceleration measurements are used by the position-command-following controller, which is constructed using linear quadratic Gaussian (LQG) techniques.
Force Control Loop Affected by Bounded Uncertainties and Unbounded Inputs for Pneumatic Actuator Systems
Authors: Khayati Karim , Bigras Pascal , Dessaint Louis-A.
Published: January 2008

The purpose of this paper is to develop an accurate closed-loop acting force technique for a pneumatic actuator, as an essential stage in the implementation of positioning control strategy. Since an analytical nonlinear structure, which linearly depends on parameter uncertainties, generically characterizes pneumatic plants, a feedback linearization design is proposed to cancel most of the resulting nonlinearities. Then, we proposed a linear state-feedback control and an additive nonlinear action to robustly bound the force error dynamics, devices which are required to handle the further parametric uncertainties and exogenous unbounded disturbances that will arise on the deduced structure. The design of the linear control gains is performed within robust closed-loop pole clustering using a linear matrix inequality approach. Finally, various experimental results illustrate the validity of the approach.
Pressure, Flow, Force, and Torque Between the Barrel and Port Plate in an Axial Piston Pump
Authors: Bergada J. M. , Watton J. , Kumar S.
Published: January 2008

This paper analyzes the pressure distribution, leakage, force, and torque between the barrel and the port plate of an axial piston pump. A detailed set of new equations is developed, which takes into account important parameters such as tilt, clearance and rotational speed, and timing groove. The pressure distribution is derived for different operating conditions, together with a complementary numerical analysis of the original differential equations, specifically written for this application and used to validate the theoretical solutions. An excellent agreement between the two approaches is shown, allowing an explicit analytical insight into barrel/port plate operating characteristics, including consideration of cavitation. The overall mean force and torques over the barrel are evaluated and show that the torque over the XX axis is much smaller than the torque over the YY axis, as deduced from other nonexplicit simulation approaches. A detailed dynamic analysis is then studied, and it is shown that the torque fluctuation over the YY axis is typically 8% of the torque total magnitude. Of particular novelty is the prediction of a double peak in each torque fluctuation resulting from the more exact modeling of the piston/port plate/timing groove pressure distribution characteristic during motion. A comparison between the temporal torque fluctuation pattern and another work shows a good qualitative agreement. Experimental and analytical results for the present study demonstrate that barrel dynamics do contain a component primarily directed by the torque dynamics.
Development of a Vehicle Stability Control System Using Brake-by-Wire Actuators
Authors: Hong Daegun , Hwang Inyong , Yoon Paljoo , Huh Kunsoo
Published: January 2008

The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional braking control systems. In order to achieve the superior braking performance through the wheel slip control, real-time information such as tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance, stability enhancement, etc. In this paper, a vehicle stability control system is developed based on the braking monitor, wheel slip controller, and optimal target slip assignment algorithm. The braking monitor estimates the tire braking force, lateral tire force, and brake disk-pad friction coefficient utilizing the extended Kalman filter. The wheel slip controller is designed based on the sliding mode control method. The target slip assignment algorithm is proposed to maintain the vehicle stability based on the direct yaw-moment controller and fuzzy logic. A hardware-in-the-loop simulator (HILS) is built including electrohydraulic brake hardware and vehicle dynamics software. The effectiveness of the proposed stability control system is demonstrated through the HILS experiment.
Mechanical Equivalent of Heat — Software for a Thermistor
Authors: Boleman Michael
Published: January 2008

The Mechanical Equivalent of Heat Apparatus from PASCO scientific provides the means for doing a simple experiment to determine the mechanical equivalent of heat, J. A necessary step of this experiment is to determine the temperature of an aluminum cylinder. By measuring the resistance of a thermistor embedded in the cylinder, one is able to determine the cylinder's temperature to ±1°C using a table of resistance versus temperature supplied by PASCO.1 To allow for a more accurate temperature determination, I have developed software to calculate the temperature to ∼ ±0.3°C.
Using a Meniscus to Teach Uncertainty in Measurement
Authors: Backman Philip
Published: January 2008

I have found that students easily understand that a measurement cannot be exact, but they often seem to lack an understanding of why it is important to know something about the magnitude of the uncertainty. This tends to promote an attitude that almost any uncertainty value will do. Such indifference may exist because once an uncertainty is determined or calculated, it remains as only a number without a concrete physical connection back to the experiment. For the activity described here—presented as a challenge—groups of students are given a container and asked to make certain measurements and to estimate the uncertainty in each of those measurements. They are then challenged to complete a particular task involving the container and a volume of water. Whether the assigned task is actually achievable, however, slowly comes into question once the magnitude of the uncertainties in the original measurements is compared to the specific requirements of the challenge.
Michelson Interferometer for Your Kitchen Table
Authors: Vollmer M. , Möllmann K.-P.
Published: January 2008

Interferometry and related technologies are well known and often used in science and industry. Examples are measurements of small distances, determining the index of refraction of gases, testing the optical quality of optical components (e.g., lenses) and measuring the surface roughness with optical profilometers (which are more or less just computerized white light Michelson interferometers).
Rogue Mantle Helium and Neon
Authors: Albarède Francis
Published: January 2008

The canonical model of helium isotope geochemistry describes the lower mantle as undegassed, but this view conflicts with evidence of recycled material in the source of ocean island basalts. Because mantle helium is efficiently extracted by magmatic activity, it cannot remain in fertile mantle rocks for long periods of time. Here, I suggest that helium with high
3
He/
4
He ratios, as well as neon rich in the solar component, diffused early in Earth's history from low-melting-point primordial material into residual refractory “reservoir” rocks, such as dunites. The difference in
3
He/
4
He ratios of ocean-island and mid-ocean ridge basalts and the preservation of solar neon are ascribed to the reservoir rocks being stretched and tapped to different extents during melting.
Arabidopsis
CLV3 Peptide Directly Binds CLV1 Ectodomain
Authors: Ogawa Mari , Shinohara Hidefumi , Sakagami Youji , Matsubayashi Yoshikatsu
Published: January 2008

CLV1, which encodes a leucine-rich repeat receptor kinase, and CLV3, which encodes a secreted peptide, function in the same genetic pathway to maintain stem cell populations in Arabidopsis shoot apical meristem. Here, we show biochemical evidence, by ligand binding assay and photoaffinity labeling, that the CLV3 peptide directly binds the CLV1 ectodomain with a dissociation constant of 17.5 nM. The CLV1 ectodomain also interacts with the structurally related CLE peptides, with distinct affinities depending on the specific amino acid sequence. Our results provide direct evidence that CLV3 and CLV1 function as a ligand-receptor pair involved in stem cell maintenance.
Natural Genetic Variation in
Lycopene Epsilon Cyclase
Tapped for Maize Biofortification
Authors: Harjes Carlos E. , Rocheford Torbert R. , Bai Ling , Brutnell Thomas P. , Kandianis Catherine Bermudez , Sowinski Stephen G. , Stapleton Ann E. , Vallabhaneni Ratnakar , Williams Mark , Wurtzel Eleanore T. , Yan Jianbing , Buckler Edward S.
Published: January 2008

Dietary vitamin A deficiency causes eye disease in 40 million children each year and places 140 to 250 million at risk for health disorders. Many children in sub-Saharan Africa subsist on maize-based diets. Maize displays considerable natural variation for carotenoid composition, including vitamin A precursors α-carotene, β-carotene, and β-cryptoxanthin. Through association analysis, linkage mapping, expression analysis, and mutagenesis, we show that variation at the
lycopene epsilon cyclase
(
lcyE
) locus alters flux down α-carotene versus β-carotene branches of the carotenoid pathway. Four natural
lcyE
polymorphisms explained 58% of the variation in these two branches and a threefold difference in provitamin A compounds. Selection of favorable
lcyE
alleles with inexpensive molecular markers will now enable developing-country breeders to more effectively produce maize grain with higher provitamin A levels.
Initiating and Cancer-Propagating Cells in
TEL-AML1
-Associated Childhood Leukemia
Authors: Hong Dengli , Gupta Rajeev , Ancliff Philip , Atzberger Ann , Brown John , Soneji Shamit , Green Joanne , Colman Sue , Piacibello Wanda , Buckle Veronica , Tsuzuki Shinobu , Greaves Mel , Enver Tariq
Published: January 2008

Understanding cancer pathogenesis requires knowledge of not only the specific contributory genetic mutations but also the cellular framework in which they arise and function. Here we explore the clonal evolution of a form of childhood precursor–B cell acute lymphoblastic leukemia that is characterized by a chromosomal translocation generating a
TEL-AML1
fusion gene. We identify a cell compartment in leukemic children that can propagate leukemia when transplanted in mice. By studying a monochorionic twin pair, one preleukemic and one with frank leukemia, we establish the lineal relationship between these “cancer-propagating” cells and the preleukemic cell in which the
TEL-AML1
fusion first arises or has functional impact. Analysis of
TEL-AML1
–transduced cord blood cells suggests that
TEL-AML1
functions as a first-hit mutation by endowing this preleukemic cell with altered self-renewal and survival properties.
Act Now (But How?)
Authors: Ruddiman William F.
Published: January 2008

Cool It
. The Skeptical Environmentalist's Guide to Global Warming.
By Bjorn Lomborg
. Alfred A. Knopf, New York, 2007. 257 pp. $21, C$27. ISBN 9780307266927. Marshall Cavendish, London, and Cyan Communications, London, 2007. 367 pp. £19.99. ISBN 9780462099125.

Developing further a theme from earlier books, Lomborg advocates spending only modest amounts to lower carbon emissions and instead focusing on improving health and reducing poverty. He argues that the increased global wealth will in the long run allow a more effective response to climate change.
Natural Streams and the Legacy of Water-Powered Mills
Authors: Walter Robert C. , Merritts Dorothy J.
Published: January 2008

Gravel-bedded streams are thought to have a characteristic meandering form bordered by a self-formed, fine-grained floodplain. This ideal guides a multibillion-dollar stream restoration industry. We have mapped and dated many of the deposits along mid-Atlantic streams that formed the basis for this widely accepted model. These data, as well as historical maps and records, show instead that before European settlement, the streams were small anabranching channels within extensive vegetated wetlands that accumulated little sediment but stored substantial organic carbon. Subsequently, 1 to 5 meters of slackwater sedimentation, behind tens of thousands of 17th- to 19th-century milldams, buried the presettlement wetlands with fine sediment. These findings show that most floodplains along mid-Atlantic streams are actually fill terraces, and historically incised channels are not natural archetypes for meandering streams.
A Shared Docking Motif in TRF1 and TRF2 Used for Differential Recruitment of Telomeric Proteins
Authors: Chen Yong , Yang Yuting , van Overbeek Megan , Donigian Jill R. , Baciu Paul , de Lange Titia , Lei Ming
Published: January 2008

Mammalian telomeres are protected by a six-protein complex: shelterin. Shelterin contains two closely related proteins (TRF1 and TRF2), which recruit various proteins to telomeres. We dissect the interactions of TRF1 and TRF2 with their shared binding partner (TIN2) and other shelterin accessory factors. TRF1 recognizes TIN2 using a conserved molecular surface in its TRF homology (TRFH) domain. However, this same surface does not act as a TIN2 binding site in TRF2, and TIN2 binding to TRF2 is mediated by a region outside the TRFH domain. Instead, the TRFH docking site of TRF2 binds a shelterin accessory factor (Apollo), which does not interact with the TRFH domain of TRF1. Conversely, the TRFH domain of TRF1, but not of TRF2, interacts with another shelterin-associated factor: PinX1.
Sensing of Viral Infection and Activation of Innate Immunity by Toll-Like Receptor 3
Authors: Vercammen Elisabeth , Staal Jens , Beyaert Rudi
Published: January 2008

Toll-like receptors (TLRs) form a major group of transmembrane receptors that are involved in the detection of invading pathogens. Double-stranded RNA is a marker for viral infection that is recognized by TLR3. TLR3 triggering activates specific signaling pathways that culminate in the activation of NF-κB and IRF3 transcription factors, as well as apoptosis, enabling the host to mount an effective innate immune response through the induction of cytokines, chemokines, and other proinflammatory mediators. In this review, we describe the paradoxical role of TLR3 in innate immunity against different viruses and in viral pathogenesis but also the evidence for TLR3 as a “danger” receptor in nonviral diseases. We also discuss the structure and cellular localization of TLR3, as well as the complex signaling and regulatory events that contribute to TLR3-mediated immune responses.
Role of Modern Imaging Techniques for Diagnosis of Infection in the Era of18F-Fluorodeoxyglucose Positron Emission Tomography
Authors: Kumar Rakesh , Basu Sandip , Torigian Drew , Anand Vivek , Zhuang Hongming , Alavi Abass
Published: January 2008

During the past several years, it has become quite evident that positron emission tomography (PET) with18F-fluorodeoxyglucose (FDG) imaging can play a major role in the management of patients with suspected infection. Particularly, several groups have demonstrated that this powerful imaging methodology is very effective in the evaluation of osteomyelitis, infected prostheses, fever of unknown origin, and AIDS. In view of its extraordinary sensitivity in detecting disease activity and the ability to quantitate the degree of FDG uptake, PET might prove to be an appropriate modality for monitoring disease activity and evaluating response to therapy. FDG-PET has many advantages over existing imaging techniques for the diagnosis of infectious diseases. These include feasibility of securing diagnostic results within 1.5 to 2 h, excellent spatial resolution, and accurate anatomical localization of sites of abnormality. The availability of PET/computed tomography as a practical tool has further enhanced the role of metabolic imaging in many settings. In the future, this modality is very likely to be employed on a routine basis for detecting, characterizing, and monitoring patients with suspected and proven infection.
Rotavirus Vaccines: an Overview
Authors: Dennehy Penelope H.
Published: January 2008

Rotavirus infection is the most common cause of severe diarrhea disease in infants and young children worldwide and continues to have a major global impact on childhood morbidity and mortality. Vaccination is the only control measure likely to have a significant impact on the incidence of severe dehydrating rotavirus disease. In 1999, a highly efficacious rotavirus vaccine licensed in the United States, RotaShield, was withdrawn from the market after 14 months because of its association with intussusception. Two new live, oral, attenuated rotavirus vaccines were licensed in 2006: the pentavalent bovine-human reassortant vaccine (RotaTeq) and the monovalent human rotavirus vaccine (Rotarix). Both vaccines have demonstrated very good safety and efficacy profiles in large clinical trials in western industrialized countries and in Latin America. Careful surveillance has not revealed any increased risk of intussusception in the vaccinated groups with either vaccine. The new rotavirus vaccines are now introduced for routine use in a number of industrialized and developing countries. These new safe and effective rotavirus vaccines offer the best hope of reducing the toll of acute rotavirus gastroenteritis in both developed and developing countries.
Update on Rapid Diagnostic Testing for Malaria
Authors: Murray Clinton K. , Gasser Robert A. , Magill Alan J. , Miller R. Scott
Published: January 2008

To help mitigate the expanding global impact of malaria, with its associated increasing drug resistance, implementation of prompt and accurate diagnosis is needed. Malaria is diagnosed predominantly by using clinical criteria, with microscopy as the current gold standard for detecting parasitemia, even though it is clearly inadequate in many health care settings. Rapid diagnostic tests (RDTs) have been recognized as an ideal method for diagnosing infectious diseases, including malaria, in recent years. There have been a number of RDTs developed and evaluated widely for malaria diagnosis, but a number of issues related to these products have arisen. This review highlights RDTs, including challenges in assessing their performance, internationally available RDTs, their effectiveness in various health care settings, and the selection of RDTs for different health care systems.