bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accurate and efficient a posteriori account of geometrical imperfections in Koiter finite element analysis
Authors: Garcea G. , Liguori F. S. , Leonetti L. , Magisano D. , Madeo A. 
Published: March 2017

SummaryThe Koiter method recovers the equilibrium path of an elastic structure using a reduced model, obtained by means of a quadratic asymptotic expansion of the finite element model. Its main feature is the possibility of efficiently performing sensitivity analysis by including a posteriori the effects of the imperfections in the reduced nonlinear equations. The state‐of‐art treatment of geometrical imperfections is accurate only for small imperfection amplitudes and linear pre‐critical behaviour. This work enlarges the validity of the method to a wider range of practical problems through a new approach, which accurately takes into account the imperfection without losing the benefits of the a posteriori treatment. A mixed solid‐shell finite element is used to build the discrete model. A large number of numerical tests, regarding nonlinear buckling problems, modal interaction, unstable post‐critical and imperfection sensitive structures, validates the proposal. Copyright © 2017 John Wiley & Sons, Ltd.
Topology optimization of microwave waveguide filters
Authors: Aage N. , Egede Johansen V. 
Published: March 2017

SummaryWe present a density‐based topology optimization approach for the design of metallic microwave insert filters. A two‐phase optimization procedure is proposed in which we, starting from a uniform design, first optimize to obtain a set of spectral varying resonators followed by a band gap optimization for the desired filter characteristics. This is illustrated through numerical experiments and comparison to a standard band pass filter design. It is seen that the carefully optimized topologies can sharpen the filter characteristics and improve performance. Furthermore, the obtained designs share little resemblance to standard filter layouts, and hence, the proposed design method offers a new design tool in microwave engineering. Copyright © 2017 John Wiley & Sons, Ltd.
A priori and a posteriori error estimates of H1‐Galerkin mixed finite element method for parabolic optimal control problems
Authors: Shakya Pratibha , Sinha Rajen Kumar 
Published: March 2017

SummaryIn this exposition, we study both a priori and a posteriori error analysis for the H1‐Galerkin mixed finite element method for optimal control problems governed by linear parabolic equations. The state and costate variables are approximated by the lowest order Raviart‐Thomas finite element spaces, whereas the control variable is approximated by piecewise constant functions. Compared to the standard mixed finite element procedure, the present method is not subject to the Ladyzhenskaya‐Babuska‐Brezzi condition and the approximating finite element spaces are allowed to be of different degree polynomials. A priori error analysis for both the semidiscrete and the backward Euler fully discrete schemes are analyzed, and
convergence properties for the state variables and the control variable are obtained. In addition, L2(L2)‐norm a posteriori error estimates for the state and control variables and
‐norm for the flux variable are also derived.
Two negative minima of the first normal stress difference in a cellulose‐based cholesteric liquid crystal: Helix uncoiling
Authors: Echeverria Coro , Almeida Pedro L. , Aguilar Gutierrez Oscar F. , Rey Alejandro D. , Godinho Maria Helena 
Published: March 2017

ABSTRACTThe shear rate dependence of material functions such as shear viscosity (η) and the first normal stress difference (N1) were given and interpreted earlier by Kiss and Porter. Their widely accepted work revealed the possibility of having a negative minimum of N1 for polymeric liquid crystals. In this work, we disclose for the first time the evidence of two negative N1 minima on a sheared cellulosic lyotropic system. The lower shear rate minimum is ascribed to the uncoiling of the cholesteric helix, as theoretically predicted earlier. Our findings contribute also to the understanding of the other minimum already reported in the literature and attributed to the nematic director tumbling mode. Moreover, the elastic change that the LC‐HPC sample undergoes during the helix unwinding of the cholesteric structure is also by means of oscillatory measurements. This study is a contribution for the understanding of the structure‐properties relationship linked with the complex rheological behavior of chiral nematic cellulose‐based systems and may help to improve their further processing. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 821–830
Zebrafish models of non‐canonical Wnt/planar cell polarity signalling: fishing for valuable insight into vertebrate polarized cell behavior
Authors: Jussila Maria , Ciruna Brian 
Published: March 2017

Planar cell polarity (PCP) coordinates the uniform orientation, structure and movement of cells within the plane of a tissue or organ system. It is beautifully illustrated in the polarized arrangement of bristles and hairs that project from specialized cell surfaces of the insect abdomen and wings, and pioneering genetic studies using the fruit fly, Drosophila melanogaster, have defined a core signalling network underlying PCP. This core PCP/non‐canonical Wnt signalling pathway is evolutionarily conserved, and studies in zebrafish have helped transform our understanding of PCP from a peculiarity of polarized epithelia to a more universal cellular property that orchestrates a diverse suite of polarized cell behaviors that are required for normal vertebrate development. Furthermore, application of powerful genetics, embryonic cell‐transplantation, and live‐imaging capabilities afforded by the zebrafish model have yielded novel insights into the establishment and maintenance of vertebrate PCP, over the course of complex and dynamic morphogenetic events like gastrulation and neural tube morphogenesis. Although key questions regarding vertebrate PCP remain, with the emergence of new genome‐editing technologies and the promise of endogenous labeling and Cre/LoxP conditional targeting strategies, zebrafish remains poised to deliver fundamental new insights into the function and molecular dynamic regulation of PCP signalling from embryonic development through to late‐onset phenotypes and adult disease states. WIREs Dev Biol 2017, 6:e267. doi: 10.1002/wdev.267This article is categorized under:

Signaling Pathways > Global Signaling Mechanisms
Early Embryonic Development > Gastrulation and Neurulation
Nervous System Development > Vertebrates: General Principles
Histology and ultrastructure of the integumental chromatophores in tokay gecko (Gekko gecko) (Linnaeus, 1758) skin
Authors: Szydłowski Paweł , Madej Jan Paweł , Mazurkiewicz-Kania Marta 
Published: March 2017

AbstractThis paper describes the relationship between the arrangement of dermal chromatophores in tokay gecko (Gekko gecko) skin and the formation of wild-type colouration, with emphasis on the ultrastructure of chromatophores. The samples of the tokay gecko skin were collected from wild-type colouration adult specimens. Morphology and distribution of chromatophores was determined by using light microscopy and transmission electron microscopy. The present study revealed that orange/red coloured skin of G. gecko contained erythrophores, which were located under basement membrane, and usually comprised deeper situated iridophores and melanophores which were form single layer with iridophores or were occupying the deepest region of dermis. In orange/red coloured skin, erythrophores were the predominant chromatophores. However in blue areas these cells occurred in small numbers or were not noticed at all. In blue pigmented areas predominated iridophores and melanophores. Iridophores were found just under basement membrane, but this superficial location of iridophores occured only in areas without erythrophores. Distribution of erythrophores, melanophores, and iridophores determines the characteristic blue colour of the tokay gecko skin with orange/red dots on the whole body.
Expression of human cytomegalovirus components in the brain tissues of patients with Rasmussen’s encephalitis
Authors: Zhang Yao , Wang Yisong , Chen Sichang , Chen Shuai , Guan Yuguang , Liu Changqing , Li Tianfu , Luan Guoming , An Jing 
Published: March 2017

AbstractRasmussen’s encephalitis (RE) is a rare and severe progressive epileptic syndrome with unknown etiology. Infection by viruses, including human cytomegalovirus (HCMV), has been speculated to be a potential trigger for RE. However, no viral antigens have been detected in the brains of patients with RE; thus, a possible clinical linkage between viral infections and RE has not been firmly established. In this study, we evaluated the expression of HCMV pp65 antigen in brain sections from 26 patients with RE and 20 non-RE patients by immunohistochemistry andin situhybridization, and assessed the associations between HCMV infection and clinical parameters. Elevated expression of HCMV pp65 protein and DNA was observed in 88.5% (23/26) and 69.2% (18/26) of RE cases, respectively. In the non-RE group, HCMV pp65 antigen was detected only in two cases (10%), both of which were negative for DNA staining. Additionally, the intensity of HCMV pp65 staining was correlated with a shorter duration of the prodromal stage, younger age of seizure onset, and more severe unilateral cortical atrophy. Elevated expression of HCMV pp65 was observed in RE brain tissue and was correlated with the clinical features of RE disease. In summary, our results suggested that HCMV infection may be involved in the occurrence and progression of RE disease. Thus, further studies are needed to determine whether early treatment with anti-HCMV antibodies could modulate the course of RE.
Childhood Family Structure and Intergenerational Income Mobility in the United States
Authors: Bloome Deirdre 
Published: March 2017

Abstract
The declining prevalence of two-parent families helped increase income inequality over recent decades. Does family structure also condition how economic (dis)advantages pass from parents to children? If so, shifts in the organization of family life may contribute to enduring inequality between groups defined by childhood family structure. Using National Longitudinal Survey of Youth data, I combine parametric and nonparametric methods to reveal how family structure moderates intergenerational income mobility in the United States. I find that individuals raised outside stable two-parent homes are much more mobile than individuals from stable two-parent families. Mobility increases with the number of family transitions but does not vary with children’s time spent coresiding with both parents or stepparents conditional on a transition. However, this mobility indicates insecurity, not opportunity. Difficulties maintaining middle-class incomes create downward mobility among people raised outside stable two-parent homes. Regardless of parental income, these people are relatively likely to become low-income adults, reflecting a new form of perverse equality. People raised outside stable two-parent families are also less likely to become high-income adults than people from stable two-parent homes. Mobility differences account for about one-quarter of family-structure inequalities in income at the bottom of the income distribution and more than one-third of these inequalities at the top.
Treatment of refractory status epilepticus with electroconvulsive therapy: Need for future clinical studies
Authors: Ray Anindya 
Published: March 2017

AbstractStatus epilepticus (SE) is a serious medical emergency. Refractory-SE non-responsive to anesthetic medication is a life threatening condition with very high mortality rate. Proper management of those cases is a big medical challenge. Over the last two decades there are anecdotal reports of successful management of such cases with electroconvulsive therapy (ECT) in 12 patients of different age group with variable pattern of seizures and different etiology. However, there is no systematic research about it. ECT is a well-known safe, easy- to-administer, low-cost therapeutic modality in the field of neuro-psychiatry. Thus its potential to treat refractory-SE which essentially lacks effective management should be evaluated in future research. The objectives of this article are to do a thorough literature review on use of ECT in refractory-SE; mechanism of action of ECT in refractory-SE; and finally formulate a working protocol for future study of using ECT in patients of refractory-SE.
Laparoscopic hemicolectomy for a patient with situs inversus totalis and colorectal cancer
Authors: Martínez Maria Labalde , Veguillas Redondo Pilar , Carlin Gatica Jorge , Ramia Angel Jose Manuel 
Published: March 2017

AbstractSitus inversus totalis is a congenital anatomic anomaly characterized by a complete inversion of thoracic and abdominal organs. We present a case of a 67 year-old patient diagnosed with situs inversus totals in his childhood who was referred for a two-month history of hematoquezia. Ascending colon cancer where found and he underwent a laparoscopic hemicolectomy with radical lymphadenectomy. An exhaustive preoperative study and a detailed planning of laparoscopic surgery including positions of operator and assistants and trocar sites have been performed to be aware of anatomic challenges. The operating time was 120 min and blood loss was minimal. Histologic examination showed a well-differentiated adenocarcinoma with serosal invasion and without lymph nodes metastasis (pT3N0). The patient was discharged on postoperative 6th day without complications. Laparoscopic surgery for colon cancer in patients with situs inversus totalis could be more difficult nevertheless a safe and feasible procedure should be performed successfully.
Experiencia en el abordaje de pacientes con complejo extrofia-epispadias en un centro de alto nivel de complejidad en Colombia, 10 años
Authors: Arenas Hoyos Juliana , Pedraza Bermeo Adriana , Pérez Niño Jaime 
Published: March 2017

Objetivos El complejo extrofia-epispadias (CEE) se considera una de las malformaciones más severas de la línea media de compromiso multisistémico. La extrofia vesical es la presentación más frecuente en el espectro del complejo. Esta patología tiene un alto impacto en la calidad de vida. A pesar de la relación entre un cierre primario temprano y mejores resultados, en nuestro medio la remisión es tardía y la experiencia es escasa. El objetivo del siguiente estudio es mostrar la experiencia en el abordaje de CEE en los últimos 10 años en una institución de alto nivel de complejidad y remisión en Colombia.Materiales y métodos Se realiza un estudio observacional descriptivo, con una serie de casos del 2006 al 2016.Resultados En 10 años, se presentaron 5 casos de CEE en un centro de alta complejidad y remisión en Colombia. La mayoría de los pacientes han tenido múltiples intervenciones; la edad del primer procedimiento fue 829 días en promedio (27,6 meses). Se ha tenido un seguimiento postoperatorio promedio de 2,8 años. No se han presentado neoplasias en el seguimiento. Las comorbilidades más frecuentes son infección y litiasis. Ninguno de los pacientes contactados reportó inicio de vida sexual. La escala International Consultation on Incontinence Questionnaire-Urinary Incontinence-Short Form (ICIQ-UI-SF) tuvo un promedio de 9 puntos. Existen factores sociales asociados en nuestro medio.Conclusión El CEE requiere un abordaje temprano y multidisciplinario en instituciones con experiencia; los resultados en continencia urinaria, función sexual, desarrollo psicosocial y calidad de vida están sujetos a tratamiento oportuno de la patología.
Some remarks on the number of solutions of some nonlinear elliptic problems
Authors: Solimini Sergio 
Published: March 2017

This paper studies the multiplicity of solutions of the problem:

\begin{align*}
-\Delta u &= f(x,u)+t\phi\quad &&\text{in }\Omega\\
u&=0 &&\text{on } \partial\Omega
\end{align*}

depending on the parameter

t

for certain terms

ϕ

. The main hypothesis on

f

is that, setting

f_{ \pm } = \lim \limits_{s\rightarrow \pm \:∞}\frac{f(x,s)}{s}

, in the interval

]f_−, f_+[

there are eigenvalues of

−Δ

with the Dirichlet homogeneous boundary conditions on

∂Ω

. Studying the « bifurcation from infinity » of the solutions of the problem, multiplicity or sharp multiplicity results are obtained in the case that such eigenvalues are the first two or the first three or only one and simple. In such a way we improve or sharpen previous results of Lazer and McKenna, Hofer, Gallouet and Kavian and of the author.

Résumé
Nous étudions le nombre de solutions du problème:

\begin{align*}
-\Delta u &= f(x,u)+t\phi\quad &&\text{dans }\Omega\\
u&=0 &&\text{sur } \partial\Omega
\end{align*}

où

ϕ

est fixée et

t

est un paramètre. L’hypothèse principale sur

f

est la suivante. Posons

f_{ \pm } = \lim \limits_{s\:\rightarrow \: \pm ∞}\frac{f(x,s)}{s}

; alors l’intervalle

]f_−, f_+[

contient au moins une valeur propre de l’opérateur

(−Δ)

avec condition de Dirichlet au bord. Nous étudions la « bifurcation de l’infini » des solutions du problème pour obtenir une estimation (dans certains cas exacte) du nombre de solutions. Nous considérons principalement les cas où

]f_−, f_+[

contient les deux premières valeurs propres, les trois premières, ou seulement une valeur propre simple. Nos résultats améliorent ou précisent certains travaux de Lazer et McKenna, Hofer, Gallouët et Kavian, et de nous-même.
On the dynamics of Bose-Einstein condensation
Authors: Buffet E. , De Smedt Ph. , Pulè J.V. 
Published: March 2017

We study a non-linear integro-differential equation describing the evolution of a gas of Bosons interacting with a heat bath. The solution is shown to exist globally. A family of Liapunov functionals is constructed and used to prove convergence to equilibrium. The linearized equation determines a semi-group of contractions. The nature of approach to equilibrium (exponential at low density, but not in the two-phase region) is studied in relation to the spectral properties of the generator of the semi-group.

Résumé
Nous étudions une équation intégro-différentielle non linéaire décrivant l’évolution d’un gaz de Bosons en interaction avec un bain thermique. Nous montrons l’existence globale de la solution. On construit une famille de fonctionnelles de Liapounov, et l’on s’en sert pour démontrer la convergence vers l’équilibre. L’équation linéarisée définit un semi-groupe de contractions. La vitesse de convergence vers l’équilibre (exponentielle en basse densité, mais non dans la région diphasique) est reliée aux propriétés spectrales du générateur de ce semi-groupe.
On the treewidth of random geometric graphs and percolated grids
Authors: Li Anshui , Müller Tobias 
Published: March 2017

Abstract
In this paper we study the treewidth of the random geometric graph, obtained by dropping n points onto the square [0,√n]2 and connecting pairs of points by an edge if their distance is at most r=r(n). We prove a conjecture of Mitsche and Perarnau (2014) stating that, with probability going to 1 as n→∞, the treewidth of the random geometric graph is 𝜣(r√n) when lim inf r>rc, where rc is the critical radius for the appearance of the giant component. The proof makes use of a comparison to standard bond percolation and with a little bit of extra work we are also able to show that, with probability tending to 1 as k→∞, the treewidth of the graph we obtain by retaining each edge of the k×k grid with probability p is 𝜣(k) if p>½ and 𝜣(√log k) if p<½.
Hawkes processes with variable length memory and an infinite number of components
Authors: Hodara Pierre , Löcherbach Eva 
Published: March 2017

Abstract
In this paper we propose a model for biological neural nets where the activity of the network is described by Hawkes processes having a variable length memory. The particularity in this paper is that we deal with an infinite number of components. We propose a graphical construction of the process and build, by means of a perfect simulation algorithm, a stationary version of the process. To implement this algorithm, we make use of a Kalikow-type decomposition technique. Two models are described in this paper. In the first model, we associate to each edge of the interaction graph a saturation threshold that controls the influence of a neuron on another. In the second model, we impose a structure on the interaction graph leading to a cascade of spike trains. Such structures, where neurons are divided into layers, can be found in the retina.
Extreme events of Markov chains
Authors: Papastathopoulos I. , Strokorb K. , Tawn J. A. , Butler A. 
Published: March 2017

AbstractThe extremal behaviour of a Markov chain is typically characterised by its tail chain. For asymptotically dependent Markov chains, existing formulations fail to capture the full evolution of the extreme event when the chain moves out of the extreme tail region, and, for asymptotically independent chains, recent results fail to cover well-known asymptotically independent processes, such as Markov processes with a Gaussian copula between consecutive values. We use more sophisticated limiting mechanisms that cover a broader class of asymptotically independent processes than current methods, including an extension of the canonical Heffernan‒Tawn normalisation scheme, and reveal features which existing methods reduce to a degenerate form associated with nonextreme states.
A unified approach for large queue asymptotics in a heterogeneous multiserver queue
Authors: Miyazawa Masakiyo 
Published: March 2017

AbstractWe are interested in a large queue in a GI/G/kqueue with heterogeneous servers. For this, we consider tail asymptotics and weak limit approximations for the stationary distribution of its queue length process in continuous time under a stability condition. Here, two weak limit approximations are considered. One is when the variances of the interarrival and/or service times are bounded, and the other is when they become large. Both require a heavy-traffic condition. Tail asymptotics and heavy-traffic approximations have been separately studied in the literature. We develop a unified approach based on a martingale produced by a good test function for a Markov process to answer both problems.
Improving Disaster Response Efforts Through the Development of a Disaster Health Care Response System
Authors: Wilson Jonathan A. , McKenzie L. Kendall , McLeod W. Terry , Darsey Damon A. , Craig Jim 
Published: March 2017

AbstractWe review the development of a disaster health care response system in Mississippi aimed at improving disaster response efforts. Large-scale disasters generate many injured and ill patients, which causes a significant utilization of emergency health care services and often requires external support to meet clinical needs. Disaster health care services require a solid infrastructure of coordination and collaboration to be effective. Following Hurricane Katrina, the state of Mississippi implemented best practices from around the nation to establish a disaster health care response system. The State Medical Response System of Mississippi provides an all-hazards system designed to support local response efforts at the time, scope, and scale required to successfully manage the incident. Components of this disaster health care response system can be replicated or adapted to meet the dynamic landscape of health care delivery following disasters. (Disaster Med Public Health Preparedness. 2017;11:600–604)