bluuebunny/crossref_metadata_2025 huggingface dataset:
Observer‐based control of linear complementarity systems
Authors: Heemels W. P. M. H. , Camlibel M. K. , Schumacher J. M. , Brogliato B.
Published: August 2010

In this paper we present observer and output‐based controller design methods for linear complementarity systems (LCS) employing a passivity approach. Due to various inherent properties of LCS, such as the presence of state jumps, mode dynamics described by differential and algebraic equations (DAEs), and regions for certain modes being lower dimensional, various observer and control design schemes that have been proposed for other classes of (hybrid) dynamical systems do not apply to LCS. In particular, we present an observer design method for LCS which is effective even in the presence of state jumps. We show the well‐posedness of the observer, in the sense of existence and uniqueness of solution trajectories for the estimated state, and prove the global exponential stability of the observation error. These two properties guarantee that the estimated state exponentially recovers the state of the system. For the problem of stabilization based on output measurements only, we adopt an observer‐based control approach in which we apply a state feedback law to the estimated state obtained from the observer. We prove that the resulting closed‐loop system is well‐posed and globally exponentially stable. In order to show the well‐posedness of the closed loop, novel well‐posedness results for LCS based on low‐index properties are presented. Copyright © 2010 John Wiley & Sons, Ltd.
LMI optimization approach to robust decentralized controller design
Authors: Labibi Batool , Marquez Horacio Jose , Chen Tongwen
Published: August 2010

A new approach for design of robust decentralized controllers for continuous linear time‐invariant systems is proposed using linear matrix inequalities (LMIs). The proposed method is based on closed‐loop diagonal dominance. Sufficient conditions for closed‐loop stability and closed‐loop block‐diagonal dominance are obtained. Satisfying the obtained conditions is formulated as an optimization problem with a system of LMI constraints. By adding an extra LMI constraint to the system of LMI constraints in the optimization problem, the robust control is addressed as well. Accordingly, the decentralized robust control problem for a multivariable system is reduced to an optimization problem for a system of LMI constraints to be feasible. An example is given to show the effectiveness of the proposed method. Copyright © 2010 John Wiley & Sons, Ltd.
Nonsmooth µ‐synthesis
Authors: Apkarian Pierre
Published: August 2010

We revisit robust complex‐ and mixed‐ µ‐synthesis problems based on upper bounds and show that they can be recast as specially structured controller design programs. The proposed reformulations suggest a streamlined handling of µ‐synthesis problems using recently developed (local) nonsmooth optimization methods, where both scalings or multipliers and a controller of given structure are obtained simultaneously. A first cut of the nonsmooth programming software for structuredH∞synthesis is made available through the MATLAB R2010b Prerelease,Robust Control Toolbox Version 3.5developed by The MathWorks, Inc. Copyright © 2010 John Wiley & Sons, Ltd.
Switched state feedback for uncertain continuous‐time systems with interval delays
Authors: Mahmoud Magdi S. , Xia Yuanqing
Published: August 2010

The objective of this paper is to design a switched robust control for a class of continuous‐time systems subject to linear fractional uncertainty and interval time delays. The controller is based on state feedback and the LMI‐based stability conditions are derived using an improved Lyapunov–Krasovskii functional. Moreover, the switching rule as well as the state feedback gains are determined from the minimization of a guaranteed cost function. The theoretical results are illustrated with a numerical example. Copyright © 2010 John Wiley & Sons, Ltd.
Weighted Kaplan–Meier estimators for two‐stage treatment regimes
Authors: Miyahara Sachiko , Wahed Abdus S.
Published: August 2010

In two‐stage randomization designs, patients are randomized to one of the initial treatments, and at the end of the first stage, they are randomized to one of the second stage treatments depending on the outcome of the initial treatment. Statistical inference for survival data from these trials uses methods such as marginal mean models and weighted risk set estimates. In this article, we propose two forms of weighted Kaplan–Meier (WKM) estimators based on inverse‐probability weighting—one with fixed weights and the other with time‐dependent weights. We compare their properties with that of the standard Kaplan–Meier (SKM) estimator, marginal mean model‐based (MM) estimator and weighted risk set (WRS) estimator. Simulation study reveals that both forms of weighted Kaplan–Meier estimators are asymptotically unbiased, and provide coverage rates similar to that of MM and WRS estimators. The SKM estimator, however, is biased when the second randomization rates are not the same for the responders and non‐responders to initial treatment. The methods described are demonstrated by applying to a leukemia data set. Copyright © 2010 John Wiley & Sons, Ltd.
Regression analysis of clustered interval‐censored data with informative cluster size
Authors: Kim Yang‐Jin
Published: August 2010

Interval‐censored data are commonly found in studies of diseases that progress without symptoms, which require clinical evaluation for detection. Several techniques have been suggested with independent assumption. However, the assumption will not be valid if observations come from clusters. Furthermore, when the cluster size relates to response variables, commonly used methods can bring biased results. For example, in a study on lymphatic filariasis, a parasitic disease where worms make several nests in the infected person's lymphatic vessels and reside until adulthood, the response variable of interest is the nest‐extinction times. As the extinction times of nests are checked by repeated ultrasound examinations, exact extinction times are not observed. Instead, data are composed of two examination points: the last examination time with living worms and the first examination time with dead worms. Furthermore, as Williamsonet al. (Statistics in Medicine2008;27:543–555) pointed out, larger nests show a tendency for low clearance rates. This association has been denoted as an informative cluster size. To analyze the relationship between the numbers of nests and interval‐censored nest‐extinction times, this study proposes a joint model for the relationship between cluster size and clustered interval‐censored failure data. A proportional hazard model with random effect and a mixed ordinal regression model are applied to failure times and cluster size, respectively. The joint model approach addresses both the association among failure times from the same cluster and the dependency of failure times on cluster size. Simulation studies are performed to assess the finite sample properties of the estimators and lymphatic filariasis data are analyzed as an illustration. Copyright © 2010 John Wiley & Sons, Ltd.
Sample size determination in step‐up testing procedures for multiple comparisons with a control
Authors: Kwong Koon Shing , Cheung Siu Hung , Wen Miin‐Jye
Published: August 2010

Step‐up procedures have been shown to be powerful testing methods in clinical trials for comparisons of several treatments with a control. In this paper, a determination of the optimal sample size for a step‐up procedure that allows a pre‐specified power level to be attained is discussed. Various definitions of power, such as all‐pairs power, any‐pair power, per‐pair power and average power, in one‐ and two‐sided tests are considered. An extensive numerical study confirms that square root allocation of sample size among treatments provides a better approximation of the optimal sample size relative to equal allocation. Based on square root allocation, tables are constructed, and users can conveniently obtain the approximate required sample size for the selected configurations of parameters and power. For clinical studies with difficulties in recruiting patients or when additional subjects lead to a significant increase in cost, a more precise computation of the required sample size is recommended. In such circumstances, our proposed procedure may be adopted to obtain the optimal sample size. It is also found that, contrary to conventional belief, the optimal allocation may considerably reduce the total sample size requirement in certain cases. The determination of the required sample sizes using both allocation rules are illustrated with two examples in clinical studies. Copyright © 2010 John Wiley & Sons, Ltd.
A nonlinear model for highly unbalanced repeated time‐to‐event data: Application to labor progression
Authors: Arunajadai Srikesh G.
Published: August 2010

The collection of repeated measurements over time on an experimental unit to study the changes over time of a certain characteristic is common in biological and clinical studies. Data of this type are also often referred to as growth curve data or repeated measures data. There arise situations when one is interested in an estimate of the time to an event, based on a characteristic that indicates progression towards the event. The assessment of the progression of labor during childbirth based on cervical dilation is one such example. Here increase in the dilation of the cervix indicates progression towards delivery. Based on how long one has been in labor and an estimate of the time to complete dilation one might make crucial decisions like the decision to administer a drug or to perform a C‐section. Here a repeated measures approach is developed to model the time to the event. The parameters of the model are estimated by a maximum likelihood approach. A general model is developed for a class of data structures and a nonlinear model is developed specific to the labor progression data. Simulations are performed to assess the methodology and conditions are suggested for predicting the time to an event. Copyright © 2010 John Wiley & Sons, Ltd.
A systems approach to livability and sustainability: Defining terms and mapping relationships to link desires with ecological opportunities and constraints
Authors: Chazal Jacqueline de
Published: August 2010

I offer a protocol for assessing the sustainability of livability. This protocol draws on a framework developed to assess vulnerability, and offers two key pertinent features. These are (a) a capacity to incorporate multiple and shifting stakeholder values and (b) a means of moving from expressions of livability to underlying ecological attributes that deliver or constrain system change. The applicability of these features to both assessing the sustainability of livability and a reappraisal given system change are illustrated using data from a study site in the French Alps. The central place of values intrudes into livability and sustainability so as to complicate the situation. Even so, the protocol presented here is able to ground the abstractions and equivocation in a transparent and explicit set of announcements. Laying the steps out in the open allows for consistency in comparison and replication without artificially removing the labile flexibility embedded in livability and sustainability. Copyright © 2010 John Wiley & Sons, Ltd.
Physicochemical and structural characteristics of cross‐linked banana starch using three cross‐linking reagents
Authors: Rodríguez‐Marín María L. , Núñez‐Santiago Carmen , Wang Ya‐Jane , Bello‐Pérez Luis A.
Published: September 2010

Banana starch was cross‐linked using different cross‐linking reagents, phosphoryl chloride (POCl3), sodium trimetaphosphate (STMP), and epichlorohydrin (ECH), under alkaline conditions. The reaction conditions were selected to produce similar pasting profiles. The effects of the different cross‐linking reagents on the physicochemical and structural characteristics of cross‐linked starches were evaluated. The microscopy study did not show difference on the surface of the granules. Slight decrease in the peak temperature and enthalpy were found in the cross‐linked banana starch. The chemical groups introduced in the starch molecules by the diverse reagents promoted the re‐association of starch chains during storage. The rheological analysis of all starch dispersion at 10% (flow curves) showed a non‐Newtonian shear‐thinning; pastes obtained were time‐independent, suggesting an important contribution of the continuous phase. Structural study showed that the cross‐linked STMP‐starch had the lowest level of amylose and the ratio short/long amylopectin chains. The three reagents used for cross‐linking presented different action mode on starch granule and its components.
Gli1 Is an Inducing Factor in Generating Floor Plate Progenitor Cells from Human Embryonic Stem Cells
Authors: Denham Mark , Thompson Lachlan H. , Leung Jessie , Pébay Alice , Björklund Anders , Dottori Mirella
Published: August 2010

Generation of mesencephalic dopamine (mesDA) neurons from human embryonic stem cells (hESCs) requires several stages of signaling from various extrinsic and intrinsic factors. To date, most methods incorporate exogenous treatment of Sonic hedgehog (SHH) to derive mesDA neurons. However, we and others have shown that this approach is inefficient for generating FOXA2+ cells, the precursors of mesDA neurons. As mesDA neurons are derived from the ventral floor plate (FP) regions of the embryonic neural tube, we sought to develop a system to derive FP cells from hESC. We show that forced expression of the transcription factor GLI1 in hESC at the earliest stage of neural induction, resulted in their commitment to FP lineage. The GLI1+ cells coexpressed FP markers, FOXA2 and Corin, and displayed exocrine SHH activity by ventrally patterning the surrounding neural progenitors. This system results in 63% FOXA2+ cells at the neural progenitor stage of hESC differentiation. The GLI1-transduced cells were also able to differentiate to neurons expressing tyrosine hydroxylase. This study demonstrates that GLI1 is a determinant of FP specification in hESC and describes a highly robust and efficient in vitro model system that mimics the ventral neural tube organizer.
Defining the fetal cardiac axis between 11 + 0 and 14 + 6 weeks of gestation: experience with 100 consecutive pregnancies
Authors: Sinkovskaya E. , Horton S. , Berkley E. M. , Cooper J. K. , Indika S. , Abuhamad A.
Published: September 2010

Objective

The purpose of this study was to establish normal fetal cardiac axis values during the first and early second trimesters of pregnancy.

Methods

This was a prospective observational cohort study in which the fetal cardiac axis was assessed during ultrasound examinations in 100 consecutive fetuses between 11 + 0 and 14 + 6 weeks of gestation. Transabdominal, and, when indicated, transvaginal, approaches were used. Intraobserver and interobserver reproducibility were calculated.

Results

The cardiac axis ranged from 34.5 to 56.8° (mean (SD) 47.6 ± 5.6°) in 94 fetuses with normal cardiac anatomy. The fetal cardiac axis tended to be significantly higher in fetuses at 11 + 0 to 11 + 6 weeks of gestation than in fetuses at 12 + 0 to 14 + 6 weeks of gestation. Congenital heart defects were found in six out of 100 fetuses, four of which had abnormal cardiac axis values at 11 + 0 to 14 + 6 weeks of gestation.

Conclusion

Cardiac axis measurement is possible in the first and early second trimesters of pregnancy. The assessment of cardiac axis at an early gestational age may help to identify pregnancies at high risk for congenital heart defects. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Participatory methods of integrated assessment—a review
Authors: Salter Jonathan , Robinson John , Wiek Arnim
Published: September 2010

The field of Participatory Integrated Assessment (PIA) is still very young, having evolved from the broader field of Integrated Assessment (IA) in the mid to late 1990s. Like IA, PIA is a problem‐based field, with a focus on interdisciplinary research. Fundamental to PIA, however, is the assertion that the quality of decisions is improved by the direct involvement of stakeholders in the assessment process—particularly when those decisions pertain to complex, intractable problems. Climate change presents just such a problem, and it is in the domains of climate change and related sustainability issues where PIA has seen its broadest application. Previous reviews have focused primarily on the mechanisms of participation in PIAs. The purpose of this review is to take a broader look at the field of PIA, focusing on components and cross‐cutting themes that appear to be defining the conduct of PIA exercises. The review first looks at common components of PIA, including methods (future scenarios and models), participation (mechanisms of participation, representation, and stages of involvement), and outcomes (policy outcomes and process outcomes). The review then turns to an examination of cross‐cutting themes in the field of PIA. These themes include the tension between qualitative and quantitative information, the role of interactivity in PIA, the importance of institutions and institutional change, and navigating the space defined by choice, uncertainty, and constraints. As governments at all levels move toward response options for climate change, PIA is increasingly becoming an approach for providing meaningful participation in the selection of those options. © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Integrated Assessment of Climate Change > Participatory Methods of Integrated Assessment

Social Status of Climate Change Knowledge > Climate Science and Decision Making
The physical concept of climate forcing
Authors: Liepert Beate G.
Published: September 2010

Since the beginning of the debate on global climate change, scientists, economists, and policy makers alike have been using ‘climate forcing’ as a convenient measure for evaluating climate change. Researchers who run complex computer models conceived the theoretical concept of climate forcing in the late 1960s (Charney Report, 1979). This overview describes the development and basics of the physical framework, as radiative energy imbalance in the atmosphere, inflicted by a perturbation in the climate system. Such disturbances and forced changes can alter processes in the climate system, which enhance or dampen the initial effects and thus introduce positive or negative feedback loops. With increased understanding of the nature of the climate system, this basic concept has become more complex and hence more difficult to interpret. The identification of additional anthropogenic disturbances, the interdependence of individual forcings, and difficulties to account for spatial and temporal variabilities of disturbances are only few issues that complicate the overall picture. Although numerous scientific studies exist that evaluate climate forcings by allocating watts per square meter values to individual forcings (Intergovernmental Panel on Climate Change (IPCC) reports, 2010), the actual number of publications that interpret the physical meaning of the climate‐forcing concept remains surprisingly small. Here, this overview focuses on explaining to an interdisciplinary audience the physical interpretation of the concept, including its limitations. It also examines new developments, such as polluter‐based emission scenarios, energy budget approaches, and climate impacts other than temperature change. WIREs Clim Change 2010 1 786–802 DOI: 10.1002/wcc.75

This article is categorized under:

Paleoclimates and Current Trends > Climate Forcing

Climate Models and Modeling > Knowledge Generation with Models
Eight years of wind measurements from scatterometer for wind resource mapping in the Mediterranean Sea
Authors: Furevik Birgitte R. , Sempreviva Anna M. , Cavaleri Luigi , Lefèvre Jean‐Michel , Transerici Claudio
Published: August 2010

Eight years of wind observations from the SeaWinds scatterometer instrument on the National Aeronautics and Space Administration QuikScat satellite and in situ data from 11 locations in the Mediterranean have been considered. The data have been co‐located in time and space, and it is shown that the scatterometer is able to provide similar long‐term statistics as available from buoy data, such as annual and monthly wind indexes. Such statistics is useful to give an overview of the climatology in the different areas. The correlation between QuikScat and in situ observations is degraded towards the coast, giving indication of how well the scatterometer can represent the coastal winds. The degradation is stronger in areas with strong spatial variability. The QuikScat winds are gridded into a 0.25° by 0.25° grid to produce seasonal and annual means of the offshore wind conditions over the Mediterranean. Copyright © 2010 John Wiley & Sons, Ltd.
Structural and functional insights into eukaryotic mRNA decapping
Authors: Ling Sharon H. M. , Qamra Rohini , Song Haiwei
Published: September 2010

The control of messenger RNA (mRNA) translation and degradation is important in regulation of eukaryotic gene expression. In the general and specialized mRNA decay pathways which involve 5′→3′ decay, decapping is the central step because it is the controlling gate preceding the actual degradation of mRNA and is a site of numerous control inputs. Removal of the cap structure is catalyzed by a decapping holoenzyme composed of the catalytic Dcp2 subunit and the coactivator Dcp1. Decapping is regulated by decapping activators and inhibitors. Recent structural and kinetics studies indicated that Dcp1 and the substrate RNA promote the closed form of the enzyme and the catalytic step of decapping is rate limiting and accelerated by Dcp1. The conformational change between the open and closed decapping enzyme is important for controlling decapping, and regulation of this transition has been proposed to be a checkpoint for determining the fate of mRNAs. Here we summarize the past and recent advances on the structural and functional studies of protein factors involved in regulating mRNA decapping. WIREs RNA 2011 2 193–208 DOI: 10.1002/wrna.44

This article is categorized under:

RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms

RNA Turnover and Surveillance > Regulation of RNA Stability
Wave propagation in an elastically supported string with point‐wise defects: gap‐band and pass‐band effects
Authors: Glushkov E. , Glushkova N. , Wauer J.
Published: August 2010

Wave excitation, propagation and diffraction phenomena as well as related resonance trap‐mode, gap‐band and pass‐band effects occurring in one‐dimensional waveguides with obstacles are considered. The waveguide is a spring‐supported string with pointwise changed cross‐section and/or spring force. The analysis is based on semi‐analytical solution in terms of the waveguide's Green functions with unknown coefficients. The latter are obtained from a linear algebraic system whose eigenvalues are spectral points of the problem considered. One of the purposes is to examine the relation between the spectral point allocation in the complex frequency plane and the resonance wave phenomena observed. It is shown that pass‐band phenomena are controlled by natural frequencies approaching to the real axis.
Tailoring the Microstructure of Sol–Gel Derived Hydroxyapatite/Zirconia Nanocrystalline Composites
Authors: Vasconcelos HC , Barreto MC
Published: August 2010

In this study, we tailor the microstructure of hydroxyapatite/zirconia nanocrystalline composites by optimizing processing parameters, namely, introducing an atmosphere of water vapor during sintering in order to control the thermal stability of hydroxyapatite, and a modified sol–gel process that yields to an excellent intergranular distribution of zirconia phase dispersed intergranularly within the hydroxyapatite matrix. In terms of mechanical behavior, SEM images of fissure deflection and the presence of monoclinic ZrO2 content on cracked surface indicate that both toughening mechanisms, stress-induced tetragonal to monoclinic phase transformation and deflection, are active for toughness enhancement.
Quantum Dot Infrared Photodetectors: Photoresponse Enhancement Due to Potential Barriers
Authors: Mitin Vladimir , Antipov Andrei , Sergeev Andrei , Vagidov Nizami , Eason David , Strasser Gottfried
Published: August 2010

Potential barriers around quantum dots (QDs) play a key role in kinetics of photoelectrons. These barriers are always created, when electrons from dopants outside QDs fill the dots. Potential barriers suppress the capture processes of photoelectrons and increase the photoresponse. To directly investigate the effect of potential barriers on photoelectron kinetics, we fabricated several QD structures with different positions of dopants and various levels of doping. The potential barriers as a function of doping and dopant positions have been determined using nextnano3 software. We experimentally investigated the photoresponse to IR radiation as a function of the radiation frequency and voltage bias. We also measured the dark current in these QD structures. Our investigations show that the photoresponse increases ~30 times as the height of potential barriers changes from 30 to 130 meV.
Le cancer de la verge : à propos d’un cas et revue de la littérature
Authors: Odzébé A.W.S. , Bouya P.A. , Nkoua Mbon J.B. , Ngatshé A. , Péko J.F.
Published: September 2010

Le cancer de la verge est rare. Il pose souvent en Afrique le problème de l’acceptabilité de l’amputation de la verge. Nous rapportons un cas de tumeur de la verge révélé après une circoncision tardive. Le traitement a consisté en une amputation des deux tiers de la verge. Le patient est vivant sans récidive locale, deux ans après la chirurgie. La revue de la littérature montre la rareté de cette tumeur et le rôle des facteurs favorisants qui sont: l’absence de circoncision et l’infection à papillomavirus.
Disruptive Symptoms In Childhood And Adolescence And Early Initiation Of Tobacco And Cannabis Use: The Gazel Youth Study
Authors: Galéra C. , Bouvard M.-P. , Melchior M. , Chastang J.-F. , Lagarde E. , Michel G. , Encrenaz G. , Messiah A. , Fombonne E.
Published: September 2010

Purpose

To examine the link between symptoms of hyperactivity-inattention and conduct disorder in childhood, and the initiation of tobacco and cannabis use, controlling for other behavioral symptoms, temperament and environmental risk factors.

Method

The sample (N = 1107 participants, aged 4 to 18 years at baseline) was recruited from the population-based longitudinal Gazel Youth study with a follow-up assessment 8 years later. Psychopathology, temperament, environmental variables, and initiation of tobacco and cannabis use were self-reported. Event time analyses were performed to assess the effects of childhood disruptive symptoms on age at first use of tobacco and cannabis.

Results

Proportional hazard models revealed that participants with high levels of childhood symptoms of both hyperactivity-inattention and conduct disorder were at highest risk of early tobacco initiation (in males: hazard ratio [HR] = 2.05; confidence interval [CI]: 1.24–3.38; in females: HR = 2.01; CI: 1.31–3.09), and, in males, of early cannabis initiation (HR = 1.95; CI: 1.04–3.64). Temperament, through activity in both males and females and negative emotionality in females, was also associated to early substance use initiation.

Conclusions

Children who simultaneously have high levels of symptoms of hyperactivity-inattention and conduct disorder are at increased risk for early substance initiation. These associations may guide childhood health professionals to consider the liability for early substance initiation in high-risk groups.
Treatment of high‐grade squamous intraepithelial lesions in an area of Thailand with a high incidence of cervical cancer
Authors: Sriprasert Intira , Kietpeerakool Chumnan , Cheewakriangkrai Chalong , Siriaree Sitthicha , Tantipalakorn Charuwan , Srisomboon Jatupol
Published: September 2010

Objective

To audit the treatment of high‐grade squamous intraepithelial lesions (HSILs) at Chiang Mai University Hospital based on 12 standard requirements of the National Health Service Cervical Screening Programme.

Methods

Records were reviewed of all women with histologically proven HSIL undergoing treatment at Chiang Mai University Hospital between January 2005 and May 2009.

Results

Four of the standard requirements were not met: not all women underwent colposcopy before definitive treatment; the rate of specimen fragmentation was high; among women with ectocervical lesions, the rate of tissue removal to a depth of greater than 7 mm was low; and among women aged over 50 years with endocervical‐margin involvement, the rate of repeat excision was low.

Conclusion

This audit highlights four treatment practices that do not meet standard requirements and require detailed exploration. The development of guidelines for the treatment of cervical precancerous lesions in Thailand is challenging and merits further attention.
Bovid mortality profiles in paleoecological context falsify hypotheses of endurance running–hunting and passive scavenging by early Pleistocene hominins
Authors: Bunn Henry T. , Pickering Travis Rayne
Published: September 2010

The world’s first archaeological traces from 2.6 million years ago (Ma) at Gona, in Ethiopia, include sharp-edged cutting tools and cut-marked animal bones, which indicate consumption of skeletal muscle by early hominin butchers. From that point, evidence of hominin meat-eating becomes increasingly more common throughout the Pleistocene archaeological record. Thus, the substantive debate about hominin meat-eating now centers on mode(s) of carcass resource acquisition. Two prominent hypotheses suggest, alternatively, (1) that earlyHomohunted ungulate prey by running them to physiological failure and then dispatching them, or (2) that earlyHomowas relegated to passively scavenging carcass residues abandoned by carnivore predators. Various paleontologically testable predictions can be formulated for both hypotheses. Here we test four predictions concerning age-frequency distributions for bovids that contributed carcass remains to the 1.8 Ma. old FLK 22Zinjanthropus(FLK Zinj, Olduvai Gorge, Tanzania) fauna, which zooarchaeological and taphonomic data indicate was formed predominantly by earlyHomo. In all but one case, the bovid mortality data from FLK Zinj violate test predictions of the endurance running-hunting and passive scavenging hypotheses. When combined with other taphonomic data, these results falsify both hypotheses, and lead to the hypothesis that earlyHomooperated successfully as an ambush predator.
Minor-Minimal Planar Graphs of Even Branch-Width
Authors: INKMANN TORSTEN , THOMAS ROBIN
Published: September 2010

Letk≥ 1 be an integer, and letHbe a graph with no isolated vertices embedded in the projective plane, such that every homotopically non-trivial closed curve intersectsHat leastktimes, and the deletion and contraction of any edge in this embedding results in an embedding that no longer has this property. LetGbe the planar double cover ofHobtained by liftingGinto the universal covering space of the projective plane, the sphere. We prove thatGis minor-minimal of branch-width 2k. We also exhibit examples of minor-minimal planar graphs of branch-width 6 that do not arise in this way.
Effects of early experience on the post-weaning acceptance of whole grain wheat by fine-wool Merino lambs
Authors: Lynch J. J. , Keogh R. G. , Elwin R. L. , Green G. C. , Mottershead B. E.
Published: September 2010

Groups of Merino lambs were exposed to wheat at different ages, for different durations, and with or without their mothers, in two experiments. Acceptance of wheat was tested during the week following weaning.

In experiment 1 the mothers had never eaten wheat; all but one group were exposed without their mothers. Lambs showed more interest in wheat at 1 to 2 weeks of age than at any other age. The only group in which there was good acceptance of wheat during testing was the group which was exposed with their mothers. The latter had been given wheat for the first time in the week prior to the lamb's exposure. The average intake of this group in 2.5 h of testing (0.5 h per day for 5 days) was 290 g per head.

In experiment 2, groups of lambs, together with their mothers who were experienced in eating wheat, had uncontrolled access to wheat trailed on the ground for different periods within the first 4 weeks after birth. Lambs in one group had access to wheat for 1 to 5 days following birth.

All lambs in experiment 2 ate wheat during testing and there were no differences in either intake or feeding times between groups. Mean intake of all groups during the 5 day test period was 810 g per head.

The results demonstrate the importance of early experience and in particular maternal influences in determining the subsequent acceptance of a wheat supplement by lambs. The results also raise questions concerning not only the nature, but also the extent of maternal influences on dietary selection.
Examining ‘Social Investment’ Policy in a Multi-Ethnic Sure Start Area: Staff Perspectives
Authors: Hamm Tricia
Published: September 2010

This article, based on a study conducted in a multi-ethnic Sure Start programme between 2003–6, explores aspects of the interface between policy, implementation and use of services. The early Sure Start discourse depicted parents both as legitimate recipients of support and as active and aspirational agents. It is argued that the second of these identities, tapping into a ‘social investment’ agenda, increasingly characterised the direction of the policy discourse. Interview data from professionals in the case study area about local need and use of services, however, emphasised the ‘constrained agency’ of many local mothers, and the inappropriateness therefore of the perceived direction of policy.
Models and Approaches in Family-Focused Policy and Practice
Authors: Hughes Nathan
Published: September 2010

A review of models and approaches to family-based policy and service provision for those at risk of social exclusion suggests three distinct categories. In the first category, approaches seek to strengthen the ability of family members to offer support to a primary service user within that family. In the second category, family members are recognised as having their own specific and independent needs arising out of their relationship with the primary service user. The third category includes ‘whole family approaches’ focused on shared needs and strengths that could not be dealt with through a focus on family members as individuals.
Bullöse Autoimmundermatosen
Authors: Hertl Michael , Niedermeier Andrea , Borradori Luca
Published: August 2010

Blasenbildende Autoimmunerkrankungen sind seltene, meist schwere Erkrankungen von Haut und Schleimhäuten, die immunologisch durch zirkulierende Antikörper gegen Adhäsionsmoleküle der Epidermis und der dermoepidermalen Junktionszone charakterisiert sind; diese führen zum Adhäsionsverlust von Haut und Schleimhäuten und klinisch zur Ausbildung von Blasen oder Erosionen. Beim Pemphigus findet der Adhäsionsverlust in der Epidermis statt, während beim Pemphigoid, der linearen IgA-Dermatose, der Epidermolysis bullosa acquisita und der Dermatitis herpetiformis Duhring der Adhäsionsverlust subepidermal, d. h. innerhalb oder unterhalb der dermoepidermalen Basalmembranzone statt findet. Die Autoantigene dieser Erkrankungen sind weitesgehend identifiziert und charakterisiert. Die Diagnostik bullöser Autoimmundermatosen basiert auf Histologie und direkter Immunfluoreszenz perilesionaler Haut sowie dem serologischen Autoantikörpernachweis mittels indirekter Immunfluoreszenz und rekombinanten Proteinen. Therapeutisch erfolgt in den meisten Fällen die systemische Therapie mit Glukokortikoiden, die mit adjuvanten Immunsuppressiva kombiniert werden, um die Steroiddosis kurzfristig reduzieren zu können. Eine prospektive Studie beim Pemphigus zeigt, dass die zusätzliche Behandlung mit Azathioprin, Mykophenolat Mofetil bzw. Cyclophosphamid die kummulative Steroiddosis bis zur klinischen Remission reduziert. Beim bullösen Pemphigoid führt die topische Therapie mit Clobetasol ohne die unerwünschten Nebenwirkungen der systemischen Steroidtherapie zu kompletten klinischen Remissionen. Die therapeutische B-Zelldepletion mit Rituximab als Second Line-Therapie hat die Prognose des Pemphigus wesentlich verbessert. Bei weiteren Erkrankungen wie der Dermatitis herpetiformis und Epidermolysis bullosa acquisita liegen vergleichbare, kontrollierte Therapiestudien bislang noch nicht vor.
Genodermatosen in der täglichen Praxis – die Rolle des Dermatologen
Authors: Itin Peter H. , Burger Bettina
Published: August 2010

Die Entwicklung einer Krankheit ist jeweils das Resultat der gegenseitigen Beeinflussung von genetischer Konstellation und Umwelteinwirkungen. Am Beispiel der Ichthyosis vulgaris und der atopischen Dermatitis wird gezeigt, wie sowohl monogene als auch polygene Erkrankungen durch Umweltkonstellationen, hier trockene Luft im Winter, den Phänotyp beeinflussen. Rund 1/3 aller monogenen Erkrankungen zeigen eine Beteiligung der Haut- und Hautanhangsgebilde (Integument). Damit ist das Integument dasjenige Organ, welches am häufigsten bei genetischen Erkrankungen mitbetroffen ist. Bis heute sind etwa 350 Genodermatosen aufgeklärt worden. Nach der Entschlüsselung des menschlichen Genoms hat das Projekt ENCODE zum Ziel die funktionellen Elemente des Genoms und Transcriptoms zu untersuchen. Für die Haut scheinen microRNAs wichtige funktionskontrollierende Aufgaben zu haben. Die wachsende Bedeutung der Epigenetik und die unterliegenden Mechanismen wie z. B. Methylierung werden besprochen. Abschließend werden praktische Tipps zum diagnostischen Vorgehen bei unbekannten Symptomenkonstellationen gegeben.
Präventiv und stigmareduzierend?
Authors: Conrad Ines , Heider Dirk , Schomerus Georg , Angermeyer Matthias C. , Riedel-Heller Steffi
Published: September 2010

Anliegen: Evaluation der präventiven und stigmareduzierenden Wirkung des eintägigen Schulprojekts «Verrückt? Na und!». Methode: Grundlage bildete ein quasi-experimentelles Längsschnittdesign mit Interventionsgruppe (IG; n = 120) und Kontrollgruppe (KG; n = 90) zu drei Messzeitpunkten. Es wurden Schüler der Jahrgänge 9 und 10 zu Schulklima, Hilfesuchverhalten und Sozialer Distanz (SD) gegenüber psychisch kranken Menschen befragt. Zusätzlich wurden beteiligte Lehrer befragt. Ergebnisse: Hinsichtlich der SD konnte ein kurzzeitiger positiver Effekt in der IG nachgewiesen werden. Die Ergebnisse zum Hilfesuchverhalten zeigen, dass im Falle einer seelischen Krise gleichaltrige Freunde an erster Stelle stehen. Schlussfolgerung: Das eintägige Projekt reduziert die SD kurzfristig und wäre somit ein guter Ausgangspunkt für die Implementierung regelmäßiger Aktivitäten. Jugendliche Betroffene können Gleichaltrigen Mut machen, einer seelischen Krise mit weniger Ängsten und Vorurteilen zu begegnen.
A statistical study on the correlation between lower ionospheric perturbations as seen by subionospheric VLF/LF propagation and earthquakes
Authors: Hayakawa M. , Kasahara Y. , Nakamura T. , Muto F. , Horie T. , Maekawa S. , Hobara Y. , Rozhnoi A. A. , Solovieva M. , Molchanov O. A.
Published: September 2010

The subionospheric VLF/LF propagation is extensively used to investigate the lower ionospheric perturbation in possible association with earthquakes. An extensive period of data over 7 yr from January 2001 to December 2007 and a combination of different propagation paths in and around Japan are used to examine the statistical correlation between the VLF/LF propagation anomaly (average nighttime amplitude, dispersion, and nighttime fluctuation) and earthquakes with magnitude >6.0. It is then found that the propagation anomaly exceeding the 2σ (standard deviation) criterion indicating the presence of ionospheric perturbation is significantly correlated with earthquakes with shallow depth (<40 km). Finally, the mechanism of seismoionospheric perturbations is discussed.
Ammonium concentration in ice cores: A new proxy for regional temperature reconstruction?
Authors: Kellerhals T. , Brütsch S. , Sigl M. , Knüsel S. , Gäggeler H. W. , Schwikowski M.
Published: August 2010

We present a reconstruction of tropical South American temperature anomalies over the last ∼1600 years. The reconstruction is based on a highly resolved and carefully dated ammonium record from an ice core that was drilled in 1999 on Nevado Illimani in the eastern Bolivian Andes. Concerning the relevant processes governing the observed correlation between ammonium concentrations and temperature anomalies, we discuss anthropogenic emissions, biomass burning, and precipitation changes but clearly favor a temperature‐dependent source strength of the vegetation in the Amazon Basin. That given, the reconstruction reveals that Medieval Warm Period– and Little Ice Age–type episodes are distinguishable in tropical South America, a region for which until now only very limited temperature proxy data have been available. For the time period from about 1050 to 1300 AD, our reconstruction shows relatively warm conditions that are followed by cooler conditions from the 15th to the 18th century, when temperatures dropped by up to 0.6°C below the 1961–1990 average. The last decades of the past millennium are characterized again by warm temperatures that seem to be unprecedented in the context of the last ∼1600 years.
Trace gas emissions from savanna fires in northern Australia
Authors: Paton‐Walsh C. , Deutscher N. M. , Griffith D. W. T. , Forgan B. W. , Wilson S. R. , Jones N. B. , Edwards D. P.
Published: August 2010

We present analyses of near‐infrared ground‐based Fourier transform infrared solar absorption spectra recorded from a site in Darwin, Northern Territory, Australia (12.4°S, 130.9°E) from August 2005 to June 2008. Total column amounts of carbon monoxide derived from these spectra show a very clear annual cycle, with evidence of transported pollution from Indonesian fires in 2006. Aerosol optical depth measurements from the same site show a similar annual cycle but without exceptional values in 2006, suggesting significant loss of aerosol loading in the transported and aged smoke. In addition, we report the first ever measurements by remote sensing solar Fourier transform infrared of emission ratios with respect to carbon monoxide for formaldehyde (0.022 ± 0.007), acetylene (0.0024 ± 0.0003), ethane (0.0020 ± 0.0003), and hydrogen cyanide (0.0018 ± 0.0003) from Australian savanna fires. These are derived from mid‐infrared spectra recorded through smoke plumes over Darwin on 20 separate days. The only previous measurements of emission ratios for formaldehyde and hydrogen cyanide from Australian savanna fires involved cryogenic trapping and storage of samples that were gathered in very fresh smoke. The results reported here are nearly an order of magnitude higher (but in agreement with laboratory studies), suggesting losses in the collection, storage, or transfer of the gases in the earlier measurements and/or chemical production of these reactive gases within the smoke plumes. Emission ratios for acetylene and ethane from this work are in broad agreement with other literature values.
Composite analysis of dust impacts on African easterly waves in the Moderate Resolution Imaging Spectrometer era
Authors: Jury Mark R. , Santiago Myrna J.
Published: August 2010

This study examines the synoptic scale impacts of African dust on easterly waves in the tropical northeast Atlantic. Moderate Resolution Imaging Spectrometer aerosol optical depth (AOD), National Oceanic and Atmospheric Administration products, and National Center for Environmental Prediction reanalysis fields in the Atlantic main hurricane development region (MDR) form the basis for statistical analysis of a limited set of cases objectively selected for the 2000–2008 hurricane seasons when thresholds are exceeded for sea surface temperature (SST), easterly wind shear, cyclonic vorticity, and upward motion. After ranking African easterly waves by AOD, the top (dusty) and bottom (clean) cases are studied as composite differences. African dust and subsidence cause temperatures to warm ∼3°C in the 700 hPa layer, while SSTs cause temperatures to cool, stabilizing the atmosphere. Increased AOD and strong (10 m s−1) 600 hPa easterly winds limit cloud efficiency through shear and oversupply of condensation nuclei. Vertical section composites demonstrate that warm dry subsident air coincides with the African dust plume in the latitudes 18°N–30°N. Hurricane reanalysis data indicate that higher AOD in the MDR reduces chances for the intensification of African easterly waves.
Experimental investigation of dynamic effects in capillary pressure: Grain size dependency and upscaling
Authors: Camps‐Roach Geremy , O'Carroll Denis M. , Newson Timothy A. , Sakaki Toshihiro , Illangasekare Tissa H.
Published: August 2010

The macroscopic flow equations used to predict two‐phase flow typically utilizes a capillary pressure‐saturation relationship determined under equilibrium conditions. Theoretical reasoning, experimental evidence, and numerical modeling results have indicated that when one fluid phase replaces another fluid, this relationship may not be unique but may depend on the rate at which the phase saturations change in response to changes in phase pressures. This nonuniqueness likely depends on a variety of factors including soil‐fluid properties and possibly physical scale. To quantify this dependency experimentally, direct measurements of equilibrium and dynamic capillary pressure‐saturation relationships were developed for two Ottawa sands with different grain sizes using a 20 cm long column. A number of replicate air‐water experiments were conducted to facilitate statistical comparison of capillary pressure‐saturation relationships. Water and air pressures and phase saturations were measured at three different vertical locations in the sand column under different desaturation rates (1) to measure local capillary pressure‐saturation relationships (static and dynamic); (2) to quantify the dynamic coefficientτ, a measure of the magnitude of observed dynamic effects, as a function of water saturation for different grain sizes and desaturation rates; (3) to investigate the importance of grain size on measured dynamic effects; and (4) to assess the importance of sample scale on the magnitude of dynamic effects in capillary pressure. A comparison of the static and dynamicPc‐Swrelationships showed that at a given water saturation, capillary pressure measured under transient water drainage conditions is statistically larger than capillary pressure measured under equilibrium or static conditions, consistent with thermodynamic theory. The dynamic coefficientτ, used in the expression relating the static and dynamic capillary pressures to the desaturation rate was dependant on porous media mean grain size but not on the desaturation rate. Results also suggest that the magnitude of the dynamic coefficient did not increase with the increased averaging volume considered in this study, as has been reported in the literature. This work suggests that dynamic effects in capillary pressure should be included in numerical models used to predict multiphase flow in systems when saturations change rapidly, particularly in fine‐grained soil systems (e.g., CO2sequestration, enhanced oil recovery, air sparging for remediation).