bluuebunny/crossref_metadata_2025 huggingface dataset:
The safety of breast‐conserving therapy in patients with breast cancer aged ≤40 years
Authors: van der Leest Marloes , Evers Lisette , van der Sangen Maurice J. C. , Poortmans Philip M. , van de Poll‐Franse Lonneke V. , Vulto Ans J. , Nieuwenhuijzen Grard A. P. , Brenninkmeijer Stefan J. , Creemers Geert‐Jan , Voogd Adri C.
Published: March 2007

BACKGROUND.

The objectives of this study were to study the probability of local control after breast‐conserving therapy (BCT) in a large population of patients with early‐stage breast cancer aged ≤40 years and to determine which factors had prognostic value.

METHODS.

All patients (n = 758) aged ≤40 years with clinical stage I or II breast cancer who underwent BCT in general hospitals in the southern part of the Netherlands between 1988 and 2002 were selected for the current analysis. BCT included local excision of the tumor followed by irradiation of the breast. Of 758 patients, 329 patients (43%) received adjuvant systemic treatment, and 36 patients (5%) underwent a microscopically incomplete excision. The median follow‐up was 8.5 years.

RESULTS.

During follow‐up, 95 patients developed a local recurrence without evidence of distant disease at the time the recurrence was diagnosed. Contralateral breast cancer was diagnosed in 59 patients. The 5‐ and 10‐year actuarial local recurrence rates were 9.0% (95% confidence interval [95% CI], 6.6–11.4%) and 17.9% (95% CI, 14.1–21.7%), respectively. In a multivariate analysis, adjuvant systemic treatment reduced the risk of local recurrence (hazards ratio [HR], 0.47; 95% CI, 0.28–0.78) and contralateral breast cancer (HR, 0.46; 95% CI, 0.24–0.87) by >50%.

CONCLUSIONS.

The risk of local recurrence in young patients who underwent BCT was reduced strongly by using adjuvant systemic treatment. This finding may provide an argument if favor of advising the use of systemic treatment for all patients aged ≤40 years who undergo BCT. Cancer 2007. © 2007 American Cancer Society.
Distribution of tuberoinfundibular peptide of 39 residues and its receptor, parathyroid hormone 2 receptor, in the mouse brain
Authors: Faber Catherine A. , Dobolyi Arpád , Sleeman Mark , Usdin Ted B.
Published: March 2007

Tuberoinfundibular peptide of 39 residues (TIP39) was identified as a potent parathyroid hormone 2 receptor (PTH2R) agonist. Existing anatomical data also support the suggestion that TIP39 is the PTH2R's endogenous ligand, but a comprehensive comparison of TIP39 and PTH2R distributions has not been performed. In the present study, we compared the distributions of TIP39 and PTH2R on adjacent mouse brain sections. In addition, we determined the locations of PTH2R‐expressing cell bodies by in situ hybridization histochemistry and by labeling β‐galactosidase driven by the PTH2R promoter in knockin mice. An excellent correlation was found between the distributions of TIP39‐containing fibers and PTH2R‐containing cell bodies and fibers throughout the brain. TIP39 and the PTH2R are abundant in medial prefrontal, insular, and ectorhinal cortices, the lateral septal nucleus, the bed nucleus of the stria terminalis, the fundus striati, the amygdala, the ventral subiculum, the hypothalamus, midline and intralaminar thalamic nuclei, the medial geniculate body, the periaqueductal gray, the ventral tegmental area, the superior and inferior colliculi, the parabrachial nuclei, the locus coeruleus, subcoeruleus and periolivary areas, and the nucleus of the solitary tract. Furthermore, even the subregional distribution of TIP39‐ and PTH2R‐immunoreactive fibers in these regions showed remarkable similarities, providing anatomical evidence that TIP39 may act on the PTH2R. Based on these observations and on previous pharmacological data, we propose that TIP39 is an endogenous ligand of the PTH2R and that they form a neuromodulator system, which is optimally positioned to regulate limbic, endocrine, and auditory brain functions. J. Comp. Neurol. 502:563–583, 2007. Published 2007 Wiley‐Liss, Inc.
Culture of Ciona intestinalis in closed systems
Authors: Joly Jean‐Stéphane , Kano Shungo , Matsuoka Terumi , Auger Helene , Hirayama Kazuko , Satoh Nori , Awazu Satoko , Legendre Laurent , Sasakura Yasunori
Published: March 2007

Improvements in closed‐system culturing methods for marine invertebrates are important prerequisites for the generalized use of transgenic lines. We discuss here the effects of several closed‐system conditions on the growth and survival of the solitary ascidian, Ciona intestinalis. In Shimoda, close to the sea, a small‐tank system was used to ensure that tanks and systems were reasonably equipped, water exchange was rapid, and animals separated to minimize the risk of infection. In Gif‐sur‐Yvette, an inland site, we tried to determine the optimal conditions to limit handling operations, and to save artificial seawater by avoiding water pollution. A mixture of at least two types of live algae was better than any single‐organism diet. With these maintenance protocols, we were able to obtain several generations of Ciona intestinalis, including several transgenic lines. Because these systems make it easier to rear Ciona intestinalis in laboratories, they increase the potentialities of this model organism for research. Developmental Dynamics 236:1832–1840, 2007. © 2007 Wiley‐Liss, Inc.
Ablation studies on the developing inner ear reveal a propensity for mirror duplications
Authors: Waldman Erik H. , Castillo Aldo , Collazo Andres
Published: March 2007

The inner ear develops from a simple ectodermal thickening known as the otic placode. Classic embryological manipulations rotating the prospective placode tissue found that the anteroposterior axis was determined before the dorsoventral axis. A small percentage of such rotations also resulted in the formation of mirror duplicated ears, or enantiomorphs. We demonstrate a different embryological manipulation in the frog Xenopus: the physical removal or ablation of either the anterior or posterior half of the placode, which results in an even higher percentage of mirror image ears. Removal of the posterior half results in mirror anterior duplications, whereas removal of the anterior half results in mirror posterior duplications. In contrast, complete extirpation results in more variable phenotypes but never mirror duplications. By the time the otocyst separates from the surface ectoderm, complete extirpation results in no regeneration. To test for a dosage response, differing amounts of the placode or otocyst were ablated. Removal of one third of the placode resulted in normal ears, whereas two‐thirds ablations resulted in abnormal ears, including mirror duplications. Recent studies in zebrafish have demonstrated a role for the hedgehog (Hh) signaling pathway in anteroposterior patterning of the developing ear. We have used overexpression of Hedgehog interacting protein (Hip) to block Hh signaling and find that this strategy resulted in mirror duplications of anterior structures, consistent with the results in zebrafish. Developmental Dynamics 236:1237–1248, 2007. © 2007 Wiley‐Liss, Inc.
Free vibration analysis of rectangular plates with cutouts allowing for transverse shear deformation and rotary inertia
Authors: Aksu Güven
Published: March 2007

The energy approach using the variational procedure in conjunction with the finite difference technique has been applied for the Mindlin theory dynamic analysis of rectangular plates with cutouts in which account is taken of the effects of both transverse shear deformation and rotary inertia. This study has clearly demonstrated that the discrepancy with the thin plate theory solutions increases with increasing values of thickness ratio β and the error due to the thin plate assumptions increases particularly for the higher modes. It is also concluded that the effect of a cutout becomes more pronounced as the thickness of the plate approaches the size of cutout.
Statistical analysis of the inelastic response of shear structures subjected to earthquakes
Authors: Rega G. , Vestroni F.
Published: March 2007

Inelastic deformations of structures subjected to strong earthquakes are commonly accepted by Aseismic Codes; some discrepancies exist in the different procedures proposed to design a structure for which the ductility demand is to be limited within acceptable values. To have a better insight into the seismic behaviour of multi‐degree‐of‐freedom structures beyond the elastic range, the dynamic elasto‐plastic response of a ten‐storey shear system under two sets of artificial and recorded accelerograms is studied considering different stiffness‐strength distributions and constitutive laws. Statistics of the results are presented, demonstrating the dependence of the overall and storey ductility values and of their ratio on the characteristics of the structure and excitation.
Non‐linear soil‐structure‐interaction analysis using dynamic stiffness or flexibility of soil in the time domain
Authors: Wolf John P. , Obernhuber Pius
Published: March 2007

The basic equation of motion to analyse the interaction of a non‐linear structure and an irregular soil with the linear unbounded soil is formulated in the time domain. The contribution of the unbounded soil involves convolution integrals of the dynamic‐stiffness coefficients in the time domain and the corresponding motions. Alternatively, a flexibility formulation for the contribution of the unbounded soil using the dynamic‐flexibility coefficients in the time domain, together with the direct‐stiffness method for the structure and the irregular soil can be applied. The dynamic‐stiffness or flexibility coefficient in the time domain is calculated as the inverse Fourier transform of the corresponding value in the frequency domain. The dynamic‐stiffness coefficient's asymptotic behaviour for high frequencies determines the singular part whose transformation exists only in the sense of a distribution. As the dynamic‐flexibility coefficient converges to zero for the frequency approaching infinity, the corresponding coefficient in the time domain is simpler to calculate, as no singular part exists. The salient features of the dynamic‐stiffness and flexibility coefficients in the time domain are illustrated using a semi‐infinite rod with exponentially increasing area. The dynamic‐flexibility coefficients in the time domain are calculated for a rigid circular disc resting on the surface of an elastic halfspace and of a layer built‐in at its base. Material damping is also introduced using the three‐parameter Kelvin and the Voigt models.
Inelastic seismic response of simple eccentric structures
Authors: Tso W. K. , Sadek A. W.
Published: March 2007

The maximum ductility demand and the edge displacement of a simple single mass eccentric model is evaluated when the system is subjected to ground motions represented by the El Centro 1940 and Taft 1952 earthquake records. The resisting elements are taken to be bilinear hysteretic. It is found that the ductility demand depends to a great extent on the energy content of the ground motions, particularly in the period range beyond the elastic period of the system. Unlike elastic response, the coincidence of uncoupled torsional and lateral frequencies does not lead to exceptionally high inelastic response. An increase by a factor of two in ductility demand is not uncommon for a system with large eccentricity as compared to a symmetrical system. Therefore, system eccentricity has a larger effect on ductility demand than earlier studies indicated. Using Clough's model to allow for stiffness degradation effect, results are found to be within 20 per cent of those calculated based on the bilinear hysteretic model.
First passage of a sliding rigid structure on a frictional foundation
Authors: Bergman L. A. , Spencer B. F.
Published: March 2007

The first passage problem for a sliding rigid block on a frictional foundation, subjected to Gaussian white noise through the foundation, is studied. A well‐posed boundary value problem is formulated from Markov process theory and solved for the ordinary moments of time to first passage by the finite element method. A range of parameters is studied representing a simple seismic base isolation system. Results of Monte Carlo simulation are given for comparison.
The seismicity of Western Scandinavia
Authors: Ambraseys N. N.
Published: March 2007

The purpose of this paper is to present the results of an evaluation of the seismicity of western Scandinavia. Intensities, with reference to the MSK scale, have been assessed for the larger earthquakes, in most cases from primary sources, and isoseismal maps have been constructed for the most important events, while for smaller shocks one or more isoseismal radii were estimated. In all, over 3,200 earthquakes have been retrieved for Northwest Europe including about 300 artificial events such as chemical explosions, rock‐bursts and mine explosions. Of these, 500 events occurred in western Scandinavia. Surface‐wave magnitudes were reassessed for 205 events, using surface‐wave amplitude‐period data, and all earthquakes recorded by more than 6 stations were relocated for the period prior to 1955. A calibration formula, obtained from the combination of macroseismic and instrumental data of the 20th century, has been used to assign magnitudes to all events for which there is macroseismic information available, thus deriving a homogeneous body of data covering a period of 180 years.

It is shown that the largest earthquake in the region since 1800 occurred on land and that it had a magnitude in excess of 6.0. This is contrary to the current belief, based on short‐term data, that the larger events in western Fennoscandia occur offshore in the continental shelf areas.
Tank damage during the may 1983 coalinga earthquake
Authors: Manos George C. , Clough Ray W.
Published: March 2007

The magnitude M = 6‐5 Coalinga earthquake of 2 May 1983 caused intense ground shaking throughout the epicentral region. Unanchored cylindrical ground supported tanks located at six sites within this oil producing area were damaged; damages included elephant's foot buckling at the base of three moderate sized tanks, joint rupture and top shell buckling in one large old rivetted tank, bottom plate rupture of a relatively new welded tank and damage to the floating roofs of 11 tanks. Also oil spilled over the top of many tanks and secondary damages occurred in pipe connections, ladders, etc.

In this paper an estimate is made of the intensity of ground motion at each of the tank sites, based on strong motion records made during the main shock and the strongest aftershock. Then response parameters specified by current codes are correlated with the damages observed at each tank site. Based on this comparison, it is concluded that current U.S. practice under‐estimates the sloshing response of tanks with floating roofs and does not adequately address the uplifting mechanism of unanchored ground supported tanks.
Tertiary systems
Authors: Hernried Alan G. , Sackman Jerome L.
Published: March 2007

Through perturbation theory, results are obtained for the dynamic response of the very light equipment component(s) of tertiary equipment‐structure systems. Both the three‐degree‐of‐freedom and multi‐degree‐of‐freedom models are examined. The case of all natural frequencies of the subsystems distinct (detuning) as well as a natural frequency of each subsystem close or equal to one another (tuning) are examined. The results should serve as a reliable and economical alternative to expensive numerical time‐integration schemes which may mask significant response due to ill‐conditioning of the combined system property matrices.
Computational aspects of a seismic performance test method using on‐line computer control
Authors: Shing Pui‐Shum B. , Mahin Stephen A.
Published: March 2007

The basic computational procedure of a newly developed seismic performance test méthod is presented and examined in this paper. This method uses a direct step‐by‐step integration technique to compute the displacement response of a test specimen subjected to a numerically specified seismic excitation record, utilizing the non‐linear restoring forces actually developed by the specimen during the experiment. Due to the limitations of the experimental procedure and conditions, special analytical assumptions and numerical methods must be adopted. The adequacy of such analytical techniques is evaluated and possible computational errors are identified. An improved numerical integration algorithm is also proposed for this specific application. It has been found that the method can be a reliable and powerful experimental tool provided appropriate analytical and numerical criteria, as discussed in this paper, are observed.
Response spectra for torsion, rocking and rigid foundations
Authors: Rutenberg Avigdor , Heidebrecht Arthur C.
Published: March 2007

Simple procedures are proposed for computing response spectra for torsional and rocking input ground motions assuming horizontally travelling waves of constant shape. It is shown that harmonic relationships exist between the rotational spectra and the corresponding translational spectra, and that SV rather than PSV is the correct basis for deriving the angular displacement, velocity and acceleration response spectra. An approximation enabling the use of the standard tripartite logarithmic response spectra is discussed. Simple expressions for ‘accidental’ eccentricity and rocking input effects are presented. Also proposed are multipliers to spectral ordinates to account for the filtering effects of rigid base mats resting on Winkler type foundations. For wave transit times shorter than half the natural period of the structure, these multipliers can be approximated by the frequency dependent averaging coefficients given in the literature, which are dependent, however, on the response, rather than the input, frequency.
Response of tanks to vertical seismic excitations
Authors: Haroun Medhat A. , Tayel Magdy A.
Published: March 2007

A method for analyzing the earthquake response of elastic, cylindrical liquid storage tanks under vertical excitations is presented. The method is based on superposition of the free axisymmetrical vibrational modes obtained numerically by the finite element method. The validity of these modes has been checked analytically and the formulation of the load vector has been confirmed by a static analysis. Two forms of ground excitations have been used: step functions and recorded seismic components. The radial and axial displacements are computed and the corresponding stresses are presented. Both fixed and partly fixed tanks are considered to evaluate the effect of base fixation on tank behaviour. Finally, tank response under the simultaneous action of both vertical and lateral excitations is calculated to evaluate the relative importance of the vertical component of ground acceleration on the overall seismic behaviour of liquid storage tanks.
Vibrations of beams fully or partially supported on elastic foundations
Authors: Eisenberger M. , Yankelevsky D. Z. , Adin M. A.
Published: March 2007

Exact stiffness and consistent mass matrices for beams on elastic foundations are derived. Using these matrices it is possible to find the natural frequencies and mode shapes of vibrations, for beams fully or partially supported on elastic foundations. Several examples are given for frequencies and mode shapes of beams partially supported on elastic foundations.
Seismic response of light internal equipment in base‐isolated structures
Authors: Kelly James M. , Tsai Hsiang‐Chuan
Published: March 2007

The seismic response of light secondary systems in a building is dependent on the response of the primary structural system to the seismic ground motion with the result that very high accelerations can be induced in such secondary systems. This response can be reduced through the use of aseismic base isolation which is a design strategy whereby the entire building can be decoupled from the damaging horizontal components of seismic ground motion by the use of some form of isolation system.

The paper presents a theoretical analysis of the response of light equipment in isolated structures and a parallel experimental programme both of which show that the use of base isolation can not only attenuate the response of the primary structural system but also reduce the response of secondary systems. Thus, the design of equipment and piping in a base‐isolated building is very much simpler than that for a conventionally founded structure: inelastic response and equipment‐structure interaction need not be considered and multiple support response analysis is rendered unnecessary.

Although an isolation system with linear elastic bearings can reduce the acceleration of the structure, it may be accompanied by large relative displacements between the structure and the ground. A system using lead‐rubber hysteretic bearings, having a force‐displacement relation which is approximately a bilinear loop, can reduce these displacements. A parallel experimental programme was carried out to investigate the response of light equipment in structures isolated using lead‐rubber bearings. The experimental results show that these bearings can dissipate energy and limit the displacement and acceleration of the structure but are less effective in reducing the accelerations in the internal equipment.

The results of both the analysis and the tests show that base isolation is a very effective method for the seismic protection of light equipment items in buildings.
Fuzzy optimum design of aseismic structures
Authors: Guang‐Yuan Wang , Wen‐Quan Wang
Published: March 2007

It was pointed out in our previous paper that there exists a vast amount of fuzzy information in both objective and constraint functions of optimum design of structures. Then the idea of fuzzy optimum design of structures was first proposed and the problem with fuzzy allowable intervals of the physical variables (structural responses and sizes) could be solved via the α‐level cut approach.

In this paper, the procedure of fuzzy optimum design of aseismic structures is further developed. For this purpose, the concepts and definitions of fuzzy predictive earthquake intensity, fuzzy response spectrum and fuzzy structural response are given. A solution of the programming problems with generalized fuzzy constraints (including both fuzzy constraint functions and their fuzzy allowable intervals) is put forward; one of its special cases is the χ‐level cut solution in Reference 1. The satisfaction degree of a fuzzy constraint function to its fuzzy allowable interval is defined, by which the problem considered is transformed into a series of non‐fuzzy programmings. Then, a series of optimum points can be obtained which make up the solution of the fuzzy programming.

As the solution of fuzzy programming contains not one but a series of optimum points, a two‐step approach is presented to the fuzzy optimum design of aseismic structures. The first step is to find out the set of minimum cost design points corresponding to different design levels. In the second step, both construction cost and earthquake‐caused loss expectation in the service life of the structure are traded off to find the optimum design level as well as a corresponding optimum design scheme.
Dynamic finite element analysis of three‐dimensional soil models with a transmitting element
Authors: Werkle Horst
Published: March 2007

A method for the dynamic finite element analysis of a non‐axisymmetric soil model with an axisymmetric boundary is presented. In the non‐axisymmetric soil domain an arbitrary discretization with three‐dimensional isoparametric solid elements is used. At the boundary a transmitting element is arranged. It is based on the semi‐analytical element of Waas and Kausel. The transformation of the stiffness matrix of the Waas/Kausel element with cyclic symmetric displacements to general displacement fields is presented. For earthquake excitation the forces acting on the discretized domain are given. The method is illustrated by the dynamic analysis of an embedded box‐type building. The distribution and magnitude of significant section forces are discussed.
Structural response for six correlated earthquake components
Authors: Ghafory‐Ashtiany Mohsen , Singh Mahendra P.
Published: March 2007

The paper examines the effect on the structural response of the inevitable correlation which exists between the six earthquake components acting along a set of structural axes. The rotational components are expressed in terms of the spatial derivatives of the translational components. For the calculation of response, modal analysis is employed so that ground response spectra can also be used as seismic input. A methodology is developed to obtain the maximum mean square response which can occur in a structure, irrespective of its orientation with respect to the impinging seismic waves. The application of this methodology for the calculation of design response is advocated, especially for asymmetric structures. For the assumed model of seismic wave motion, the numerical results show a significant contribution to the response from the rotational components. This contribution is, however, expected to be reduced by structural foundation averaging and interaction effects. Further studies with more complete models of seismic wave motions, and their interaction with structural foundations, are thus warranted for a realistic evaluation and characterization of the rotational inputs for design purposes.
Earthquake analysis of arch dams including dam–water interaction, reservoir boundary absorption and foundation flexibility
Authors: Fok Ka‐Lun , Chopra Anil K.
Published: March 2007

The available substructure method and computer program for the steady‐state, harmonic response analysis of arch dams, including the hydrodynamic effects, are extended to consider flexibility of the foundation rock and to include Fourier synthesis of harmonic responses to obtain the earthquake response of arch dams. By efficient evaluation of hydrodynamic terms, interpolation of frequency response functions and more efficient computer programming, the computational costs for analysing arch dams have been reduced by an order of magnitude relative to the available procedure.
Fire‐cracked rock features on sandy landforms in the Northern Rocky Mountains: Toward establishing reliable frames of reference for assessing site integrity
Authors: Thoms Alston V.
Published: March 2007

In cool coniferous forest settings of the Northern Rocky Mountains, well‐preserved fire‐cracked rock (FCR) features within 30 cm of the surface on ostensibly stable, sandy upland landforms date to the last six millennia. Isolated FCR and artifacts sometimes extend a meter or more below surface, which is suggestive of in situ burial. A paucity of intact features in the lower solum, however, is consistent with the downward migration of deeply buried artifacts by biomechanical processes, especially floralturbation. Moreover, an absence of credible sediment source areas usually precludes colluvial deposition, and results of grain‐size analysis reported herein are inconsistent with eolian deposition. Site disarticulation rates tend to be faster on landforms in warmer forested regions of south‐central North America, given that most intact FCR features there date only to the last two millennia. The very presence of millennia‐old FCR features in these diverse settings, however, is a testament to their durability and utility as measures of site integrity. © 2007 Wiley Periodicals, Inc.
Depression in older adults: exploring the relationship between goal setting and physical health
Authors: Street Helen , O'Connor Moira , Robinson Hayley
Published: March 2007

Depression in older adults is associated with a decreased quality of life, increased physical and emotional suffering and an increased risk of death and is often associated with declining physical health. Older people with physical illness have higher rates of depression and studies have also noted the particularly high rate of co‐morbidity between depressive disorder and general medical conditions. However, other studies have shown those suffering from poor physical health do not necessarily become depressed and, in particular, the goal setting style of the individual impacts on the relationship between poor physical health and depression. This study argues that those who are conditional goal setters and suffer from poorer physical health will be more prone to depression as their perceived ability to achieve their goals is negatively impacted. One hundred and eighty‐seven participants were recruited for this study. The participants completed the Centre for Epidemiological Studies Depression Inventory and the physical health subscale of the SF‐12 Health Survey. Participants were asked to rank their three most important goals and to give the main reason for setting each of their top three goals. The results showed that poorer physical health is associated with higher depression scores. Correlations revealed significant negative associations between physical health and depression, physical health and progress towards goal and progress towards goal and depression. A partial correlation between physical health and depression scores controlling for progress demonstrated that the relationship between physical health and depression is mediated through perceived progress. Implications for clinical practice are highlighted. Copyright © 2007 John Wiley & Sons, Ltd.
Modeling low‐frequency fluctuation and hemodynamic response timecourse in event‐related fMRI
Authors: Kay Kendrick N. , David Stephen V. , Prenger Ryan J. , Hansen Kathleen A. , Gallant Jack L.
Published: March 2007

Functional magnetic resonance imaging (fMRI) suffers from many problems that make signal estimation difficult. These include variation in the hemodynamic response across voxels and low signal‐to‐noise ratio (SNR). We evaluate several analysis techniques that address these problems for event‐related fMRI. (1) Many fMRI analyses assume a canonical hemodynamic response function, but this assumption may lead to inaccurate data models. By adopting the finite impulse response model, we show that voxel‐specific hemodynamic response functions can be estimated directly from the data. (2) There is a large amount of low‐frequency noise fluctuation (LFF) in blood oxygenation level dependent (BOLD) time‐series data. To compensate for this problem, we use polynomials as regressors for LFF. We show that this technique substantially improves SNR and is more accurate than high‐pass filtering of the data. (3) Model overfitting is a problem for the finite impulse response model because of the low SNR of the BOLD response. To reduce overfitting, we estimate a hemodynamic response timecourse for each voxel and incorporate the constraint of time‐event separability, the constraint that hemodynamic responses across event types are identical up to a scale factor. We show that this technique substantially improves the accuracy of hemodynamic response estimates and can be computed efficiently. For the analysis techniques we present, we evaluate improvement in modeling accuracy via 10‐fold cross‐validation. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Mutual‐information‐based approach for neural connectivity during self‐paced finger lifting task
Authors: Chen Chun‐Chuan , Hsieh Jen‐Chuen , Wu Yu‐Zu , Lee Po‐Lei , Chen Shyan‐Shiou , Niddam David M. , Yeh Tzu‐Chen , Wu Yu‐Te
Published: March 2007

Frequency‐dependent modulation between neuronal assemblies may provide insightful mechanisms of functional organization in the context of neural connectivity. We present a conjoined time‐frequency cross mutual information (TFCMI) method to explore the subtle brain neural connectivity by magnetoencephalography (MEG) during a self‐paced finger lifting task. Surface electromyogram (sEMG) was obtained from the extensor digitorum communis. Both within‐modality (MEG‐MEG) and between‐modality studies (sEMG‐MEG) were conducted. The TFCMI method measures both the linear and nonlinear dependencies of the temporal dynamics of signal power within a pre‐specified frequency band. Each single trial of MEG across channels and sEMG signals was transformed into time‐frequency domain with use of the Morlet wavelet to obtain better temporal spectral (power) information. As compared to coherence approach (linear dependency only) in broadband analysis, the TFCMI method demonstrated advantages in encompassing detection for the mesial frontocentral cortex and bilateral primary sensorimotor areas, clear demarcation of event‐ and non‐event‐related regions, and robustness for sEMG ‐ MEG between‐modality study, i.e., corticomuscular communication. We conclude that this novel TFCMI method promises a possibility to better unravel the intricate functional organizations of brain in the context of oscillation‐coded communication. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Relation between muscle and brain activity during isometric contractions of the first dorsal interosseus muscle
Authors: van Duinen Hiske , Renken Remco , Maurits Natasha M. , Zijdewind Inge
Published: March 2007

We studied the relationship between muscle activity (electromyography, EMG), force, and brain activity during isometric contractions of the index finger, on a group and individual level. Ten subjects contracted their right or left index finger at 5, 15, 30, 50, and 70% of their maximal force. Subjects received visual feedback of the produced force. We focused our analysis on brain activation that correlated with EMG. Brain activity of specific anatomical areas (region‐of‐interest analysis, ROI) was quantified and correlated with EMG activity. Furthermore, we tried to distinguish between brain areas in which activity was modulated by the amount of EMG and areas that were active during the task but in which the activity was not modulated. Therefore, we used two regressors simultaneously: (1) the produced EMG and (2) the task (a categorical regressor). As expected, activity in the motor areas (contralateral sensorimotor cortex, premotor areas, and ipsilateral cerebellum) strongly correlated with the amount of EMG. In contrast, activity in frontal and parietal areas (inferior part of the right precentral sulcus, ipsilateral supramarginal gyrus, bilateral inferior parietal lobule, bilateral putamen, and insular cortex) correlated with activation per se, independently of the amount of EMG. Activity in these areas was equal during contractions of the right or left index finger. We suppose that these areas are more involved in higher order motor processes during the preparatory phase or monitoring feedback mechanisms. Furthermore, our ROI analysis showed that muscle and brain activity strongly correlate in traditional motor areas, both at group and at subject level. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
An assessment of some open issues in the analysis of foreign exchange intervention
Authors: Vitale Paolo
Published: March 2007

We discuss some fundamental aspects of the study of foreign exchange intervention. In particular, we analyse some unresolved issues, such as the secrecy puzzle, the relevance of the signalling and portfolio‐balance effect hypotheses, the identification of the impact of foreign exchange intervention on currency values. We argue that: (i) the unresolved nature of these issues is partly due to the absence of a market microstructure perspective in most of the existing analysis of foreign exchange intervention; and (ii) that recent promising advances in this strand of research have not fully exploited the potential of such perspective. Copyright © 2007 John Wiley & Sons, Ltd.
DFT studies using supercells and projector‐augmented waves for structure, energetics, and dynamics of glycine, alanine, and cysteine
Authors: Maul R. , Ortmann F. , Preuss M. , Hannewald K. , Bechstedt F.
Published: March 2007

A large variety of gas phase conformations of the amino acids glycine, alanine, and cysteine is studied by numerically efficient semi‐local gradient‐corrected density functional theory calculations using a projector‐augmented wave scheme and periodic boundary conditions. Equilibrium geometries, conformational energies, dipole moments, vibrational modes, and IR optical spectra are calculated from first principles. A comparison of our results with values obtained from quantum‐chemistry methods with localized basis sets and nonlocal exchange‐correlation functionals as well as with experimental data is made. For conformations containing strong intramolecular hydrogen bonds deviations in their energetic ordering occur, which are traced back to different treatments of spatial nonlocality in the exchange‐correlation functional. However, even for these structures, the comparison of calculated and measured vibrational frequencies shows satisfying agreement. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007.
Time‐correlated single photon counting FLIM: Some considerations for physiologists
Authors: Medine Claire N. , Mcdonald Angela , Bergmann Axel , Duncan Rory R.
Published: March 2007

Recent developments in cellular imaging now permit the minimally invasive study of protein interactions in living cells. These advances are of enormous interest to cell biologists, as proteins rarely act in isolation, but rather in concert with others in forming cellular machinery. Up until recently, all protein interactions had to be determined in vitro using biochemical approaches. This biochemical legacy has provided cell biologists with the basis to test defined protein‐protein interactions not only inside cells, but now also with spatial resolution. More recent developments in TCSPC imaging are now also driving towards being able to determine protein interaction rates with similar spatial resolution, and together, these experimental advances allow investigators to perform biochemical experiments inside living cells. Here, we discuss some findings we have made along the way which may be useful for physiologists to consider. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Vertex partitions and maximum degenerate subgraphs
Authors: Matamala Martín
Published: March 2007

Let G be a graph with maximum degree d≥ 3 and ω(G)≤ d, where ω(G) is the clique number of the graph G. Let p1 and p2 be two positive integers such that d = p1 + p2. In this work, we prove that G has a vertex partition S1, S2 such that G[S1] is a maximum order (p1‐1)‐degenerate subgraph of G and G[S2] is a (p2‐1)‐degenerate subgraph, where G[Si] denotes the graph induced by the set Si in G, for i = 1,2. On one hand, by using a degree‐equilibrating process our result implies a result of Bollobas and Marvel [1]: for every graph G of maximum degree d≥ 3 and ω(G)≤ d, and for every p1 and p2 positive integers such that d = p1 + p2, the graph G has a partition S1,S2 such that for i = 1,2, Δ(G[Si])≤ pi and G[Si] is (pi‐1)‐degenerate. On the other hand, our result refines the following result of Catlin in [2]: every graph G of maximum degree d≥ 3 has a partition S1,S2 such that S1 is a maximum independent set and ω(G[S2])≤ d‐1; it also refines a result of Catlin and Lai [3]: every graph G of maximum degree d≥ 3 has a partition S1,S2 such that S1 is a maximum size set with G[S1] acyclic and ω(G[S2])≤ d‐2. The cases d = 3, (d,p1) = (4,1) and (d,p1) = (4,2) were proved by Catlin and Lai [3]. © 2007 Wiley Periodicals, Inc. J Graph Theory 55: 227–232, 2007
Formation of the hinge in the podocopan ostracode Loxoconcha pulchra
Authors: Yamada Shinnosuke
Published: March 2007

The hinge structure in the podocopan ostracode Loxconcha pulchra was examined throughout its molt cycle using ultrastructural and histological procedures. The structure consists of ligament and hingement, and develops along the attached margin of the right and left valves. In Stage C the hingement of both valves interdigitates beneath the ligament, and a series of outer epidermal cells (dorsal epidermal cells), exhibiting abundant granules, underlie the hinge structure. Apolysis occurs at Stage D1, and electron‐dense granular materials of variable diameter are seen within the ecdysial space. Epicuticle formation begins at Stage D2 and is complete before Stage D4. In Stage D2 the new epicuticle appears as a dotted line consisting of numerous grain‐like materials. The dorsal epidermal cells, which actively secrete the numerous granules during molting, increase their size and reveal the electron‐dense substances in the cytoplasm from Stage D2. At early Stage D3 the procuticle deposition of ligament commences inside the epicuticle, and is completed in Stage D4. In Stage D4 the uncalcified procuticle is secreted under the whole area of carapace, and the new carapace is then ready for ecdysis. After ecdysis, calcification of the carapace commences from the dorsal and ventral marginal areas towards the central area. During Stage A there is no further cuticle deposition in the ligament, although the dorsal epidermal cells secrete as actively in the postmolt stage as in premolt. The dorsal epidermal cells begin to form the hingement just after ecdysis. Cuticle deposition of the hingement proceeds asynchronously in the two valves: the hingement of the right valve is formed prior to that of left one in L. pulchra. The right hingement functions as a mold for the left hingement to form the precise interdigitated structure in L. pulchra. These observations suggest that the ostracode ligament is a unique cuticle, which should not be confused with the cuticles of other arthropods. The work establishes, for the first time, a description of the formation of the hingement in podocopan ostracodes. J. Morphol. © 2007 Wiley‐Liss, Inc.
Performance characteristics of a new prototype for a portable GC using ambient air as carrier gas for on‐site analysis
Authors: Sanchez Juan M. , Sacks Richard D.
Published: March 2007

The performance characteristics of a portable GC instrument requiring no compressed gas supplies and using relatively lightweight transportable components for the analysis of volatile organic components in large‐volume air samples are described. To avoid the need for compressed gas tanks, ambient air is used as the carrier gas, and a vacuum pump is used to pull the carrier gas and injected samples through the wall‐coated capillary column and a photoionization detector (PID). At‐column heating is used eliminating the need for a conventional oven. The fused silica column is wrapped with heater wire and sensor wire so that heating is provided directly at the column. A PID is used since it requires no external gas supplies and has high sensitivity for many compounds of interest in environmental air monitoring. In order to achieve detection limits in the ppb range, an online multibed preconcentrator containing beds of graphitized carbons and carbon molecular sieves is used. After sample collection, the flow direction through the preconcentrator is reversed, and the sample is thermally desorbed directly into the column. Decomposition of sensitive compounds during desorption is greater with air as the carrier gas than with hydrogen.
Superheated water as chromatographic eluent for parabens separation on octadecyl coated zirconia stationary phase
Authors: Dugo Paola , Buonasera Katia , Crupi Maria Lucia , Cacciola Francesco , Dugo Giovanni , Mondello Luigi
Published: March 2007

In this study, the use of pure water at superheated temperatures, between 100 and 200°C, as a mobile phase for RP separation is explored. Instrumental parameters, such as temperature, flow rate, preheating and cooling, have shown significant effects on the quality of the chromatographic peaks. The properties of superheated water as an eluent were investigated by observing the chromatographic behaviour of four parabens on a carbon‐clad zirconia (ZR) phase with covalently bonded octadecyl groups. Results were compared with those obtained at 30°C on a silica‐based phase with octadecyl groups, using water and ACN as mobile phase. The optimized method was finally applied to analyse parabens in a commercial body cream.
Liver Transplantation in Children with Sickle-Cell Disease†
Authors: Mekeel Kristin L. , Langham Max R. , Gonzalez-Peralta Regino , Fujita Shiro , Hemming Alan W.
Published: March 2007

Severe liver disease is an unusual but potentially fatal complication of sickle-cell disease (SCD). Liver transplantation has been complicated by ongoing SCD and thrombosis. We reviewed 214 pediatric transplants done at our institution from 1990 to 2005. Three patients were transplanted for complications of SCD, including intrahepatic cholestasis and viral hepatitis. Overall patient and graft survival was 66%. One patient died after 6 years from a subdural hematoma. There were not any incidences of graft loss, primary nonfunction, or thrombosis. All 3 patients required between 1 and 4 postoperative transfusions to keep hemoglobin (Hgb) >9 g/dL with an S fraction of less than 25%. One patient required a preoperative transfusion for a hemoglobin S (HbS) fraction of 30%. Mean follow-up has been 4.2 years (range, 2.6–5.4 years). All 3 children continued to suffer sequelae from their SCD. One child suffered from recurrent sickle-cell hepatopathy and chronic graft failure. In conclusion, children with SCD can in rare instances develop acute and chronic liver failure. These children can be successfully transplanted with good outcomes. Careful attention must be paid to HbS fraction and hemoglobin level to prevent sickling and vascular thrombosis. Unfortunately, liver transplant cannot alter the natural course of the disease. Liver Transpl 13:505–508, 2007. © 2007 AASLD.
Working Up Donors for High-Urgency and Elective Adult-To-Adult Live Donor Liver Transplantation†
Authors: Chan See Ching , Fan Sheung Tat , Liu Chi Leung , Lo Chung Mau , Lam Banny K. , Lee Evelyn W.
Published: March 2007

Donor workup for adult-to-adult live donor liver transplantation is done to ensure that the donor remains physically and psychologically healthy after saving or improving the life of the recipient. Even though two-thirds of the liver transplants in our center were from live donors, this life-saving procedure remains a mere treatment option, given the magnitude of the donor operation with the associated donor risks. Live donor liver transplantation was also adopted for high-urgency situations provided that the donor was suitable and the recipient considered salvageable. Donor workup in this setting had not been reported in the literature. In this cohort of 399 potential donors, 128 (32.1%) ultimately underwent donor surgery. Donors in the high-urgency situation had a lower operation rate of 28.4% (64/225) compared with that of 36.8% (64/174) of donors in the elective situation (P = 0.049). Dropouts from step 1 mainly because of ABO incompatibility, positive hepatitis serology, comorbidities, and voluntary donor withdrawal were 52.6% (210/399). Only 11.6% (22/189) of the potential donors who proceeded to subsequent steps of the workup dropped out (2 were psychologically unsuitable, 10 were anatomically prohibitive). The transplantation rate of potential recipients with 1 or more potential donors was also high. The rates were similar for the high-urgency (55%, 64/116) and the elective (51%, 64/125) situations. In a region with scarcity of deceased donor liver grafts, careful and expeditious initial donor workup minimizes dropouts from subsequent steps and allows timely transplantation in high-urgency situations. Liver Transpl 13:509–515, 2007. © 2007 AASLD.