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Ground state solutions of elliptic problems have been analysed extensively in the theory of partial differential equations, as they represent fundamental spatial patterns in many model equations. While the results for scalar equations, as well as certain specific classes of elliptic systems, are comprehensive, much less is known about these localised solutions in generic systems of nonlinear elliptic equations. In this paper we present a general method to prove constructively the existence of localised radially symmetric solutions of elliptic systems on R d . Such solutions are essentially described by systems of non-autonomous ordinary differential equations. We study these systems using dynamical systems theory and computer-assisted proof techniques, combining a suitably chosen Lyapunov–Perron operator with a Newton–Kantorovich type theorem. We demonstrate the power of this methodology by proving specific localised radial solutions of the cubic Klein–Gordon equation on R 3 , the Swift–Hohenberg equation on R 2 , and a three-component FitzHugh–Nagumo system on R 2 . These results illustrate that ground state solutions in a wide range of elliptic systems are tractable through constructive proofs. [ABSTRACT FROM AUTHOR]

In this paper, we study travelling front solutions for nonlocal equations of the type ∂ t u = N ∗ S (u) + ∇ F (u) , u (t , x) ∈ R d. Here, N ∗ denotes a convolution-type operator in the spatial variable x ∈ R , either continuous or discrete. We develop a Morse-type theory, the Conley–Floer homology, which captures travelling front solutions in a topologically robust manner, by encoding fronts in the boundary operator of a chain complex. The equations describing the travelling fronts involve both forward and backward delay terms, possibly of infinite range. Consequently, these equations lack a natural phase space, so that classic dynamical systems tools are not at our disposal. We therefore develop, from scratch, a general transversality theory, and a classification of bounded solutions, in the absence of a phase space. In various cases the resulting Conley–Floer homology can be interpreted as a homological Conley index for multivalued vector fields. Using the Conley–Floer homology, we derive existence and multiplicity results on travelling front solutions. [ABSTRACT FROM AUTHOR]

In this paper we develop a general computer-assisted proof method for periodic solutions to delay differential equations. The class of problems considered includes systems of delay differential equations with an arbitrary number of (forward and backward) delays. When the nonlinearities include nonpolynomial terms we introduce auxiliary variables to first rewrite the problem into an equivalent polynomial one. We then apply a flexible fixed point technique in a space of geometrically decaying Fourier coefficients. We showcase the efficacy of this method by proving periodic solutions in the well-known Mackey–Glass delay differential equation for the classical parameter values. [ABSTRACT FROM AUTHOR]

This contribution focusses on some of the digital theological expressions of Stephan Joubert from an auto-ethnographic angle. Orientating from a practical theology perspective, I have chosen the social media platform Twitter, and more specifically the @stephanjoubert domain, as source to chart some significant tweet expressions for the purpose of describing the character and value of an aphoristic theology. In order to do so, I have used some randomly selected tweets of Stephan Joubert, spanning the period 2020--2021, which express aspects of a relevant contemporary ecclesiology. Against the backdrop of the disastrous impact of the COVID-19 pandemic as well as some important dates on the Christian calendar (Easter and Christmas), I specifically emphasise the significance of the formulation of an aphoristic theology using amongst other markers of simplicity, contextuality and relevance. [ABSTRACT FROM AUTHOR]

In this paper, a general method to obtain constructive proofs of existence of periodic orbits in the forced autonomous Navier–Stokes equations on the three-torus is proposed. After introducing a zero finding problem posed on a Banach space of geometrically decaying Fourier coefficients, a Newton–Kantorovich theorem is applied to obtain the (computer-assisted) proofs of existence. The required analytic estimates to verify the contractibility of the operator are presented in full generality and symmetries from the model are used to reduce the size of the problem to be solved. As applications, we present proofs of existence of spontaneous periodic orbits in the Navier–Stokes equations with Taylor–Green forcing. [ABSTRACT FROM AUTHOR]

In this paper we present a general approach to rigorously validate Hopf bifurcations as well as saddle-node bifurcations of periodic orbits in systems of ODEs. By a combination of analytic estimates and computer-assisted calculations, we follow solution curves of cycles through folds, checking along the way that a single nondegenerate saddle-node bifurcation occurs. Similarly, we rigorously continue solution curves of cycles starting from their onset at a Hopf bifurcation. We use a blowup analysis to regularize the continuation problem near the Hopf bifurcation point. This extends the applicability of validated continuation methods to the mathematically rigorous computational study of bifurcation problems. [ABSTRACT FROM AUTHOR]

In this paper, we present a generalization of the parameterization method, introduced by Cabré, Fontich and De la Llave, to center manifolds associated to non-hyperbolic fixed points of discrete dynamical systems. As a byproduct, we find a new proof for the existence and regularity of center manifolds. However, in contrast to the classical center manifold theorem, our parameterization method will simultaneously obtain the center manifold and its conjugate center dynamical system. Furthermore, we will provide bounds on the error between approximations of the center manifold and the actual center manifold, as well as bounds for the error in the conjugate dynamical system. [ABSTRACT FROM AUTHOR]

As part of the search for relevant and contextual articulations of theology, this article provides an overview of a comprehensive research project that explored, described and analysed Christian motifs on Twitter. Based on the brief overview of the project, perspectives for the formulation of a Twitter theology are presented from a practical theological orientation. Two central markers are indicated and described as primary drivers of a Twitter theology: the first marker places its focus on the relationship, dynamics and functioning of aspects of authority and normativity in facilitating a Twitter theology. The second marker puts particular emphasis on the value and significance of using aphoristic formulations in the elucidation of a comprehensible Twitter theology. The article presents important strategic perspectives on the practice of a Twitter theology, as well as the formulation of a relevant contextual theology. [ABSTRACT FROM AUTHOR]

To make progress toward better computability of Morse–Floer homology and thus enhance the applicability of Floer theory, it is essential to have tools to determine the relative index of equilibria. Since even the existence of nontrivial stationary points is often difficult to accomplish, extracting their index information is usually out of reach. In this paper, we establish a computer-assisted proof approach to determining relative indices of stationary states. We introduce the general framework and then focus on three example problems described by partial differential equations to show how these ideas work in practice. Based on a rigorous implementation, with accompanying code made available, we determine the relative indices of many stationary points. Moreover, we show how forcing results can be then used to prove theorems about connecting orbits and traveling waves in partial differential equations. [ABSTRACT FROM AUTHOR]

In this paper we develop a symmetry preserving method for the rigorous computation of stationary states of the Ohta-Kawasaki partial differential equation in three space dimensions. By preserving the relevant symmetries we achieve an enormous reduction in computational cost. This makes it feasible to construct computer-assisted proofs of complex three-dimensional structures. In particular, we provide the first existence proofs for both the double gyroid and body centered cubic packed sphere solutions to this problem. [ABSTRACT FROM AUTHOR]

Traveling waves form a prominent feature in the dynamics of scalar reaction-diffusion equations on unbounded cylinders. The traveling waves can be identified with the bounded solutions of the elliptic PDE{∂2tu-c∂tu + Δu + f(x,u)= 0, t ϵ R, X ϵ Ω, B(u) = 0, t ϵ R, x ϵ ∂Ω where c ≠ 0 is the wave speed, Ω ⊂ Rd d is a bounded domain, Δ is the Laplacian on \Omega, and B denotes Dirichlet, Neumann, or periodic boundary data. We develop a new homological invariant for the dynamics of the bounded solutions of the above elliptic PDE. Restrictions on the nonlinearity f are kept to a minimum; for instance, any nonlinearity exhibiting polynomial growth in u can be considered. In particular, the set of bounded solutions of the traveling wave PDE may not be uniformly bounded. Despite this, the homology is invariant under lower order (but not necessarily small) perturbations of the nonlinearity f, thus making the homology amenable for computation. Using the new invariant we derive lower bounds on the number of bounded solutions of our PDE, thus obtaining existence and multiplicity results for traveling wave solutions of reaction-diffusion equations on unbounded cylinders. [ABSTRACT FROM AUTHOR]

Wright's conjecture states that the origin is the global attractor for the delay differential equation y ′ ( t ) = − α y ( t − 1 ) [ 1 + y ( t ) ] for all α ∈ ( 0 , π 2 ] when y ( t ) > − 1 . This has been proven to be true for a subset of parameter values α . We extend the result to the full parameter range α ∈ ( 0 , π 2 ] , and thus prove Wright's conjecture to be true. Our approach relies on a careful investigation of the neighborhood of the Hopf bifurcation occurring at α = π 2 . This analysis fills the gap left by complementary work on Wright's conjecture, which covers parameter values further away from the bifurcation point. Furthermore, we show that the branch of (slowly oscillating) periodic orbits originating from this Hopf bifurcation does not have any subsequent bifurcations (and in particular no folds) for α ∈ ( π 2 , π 2 + 6.830 × 10 − 3 ] . When combined with other results, this proves that the branch of slowly oscillating solutions that originates from the Hopf bifurcation at α = π 2 is globally parametrized by α > π 2 . [ABSTRACT FROM AUTHOR]

In this paper, we prove existence of symmetric homoclinic orbits for the suspension bridge equation u ⁗ + β u ″ + e u − 1 = 0 for all parameter values β ∈ [ 0.5 , 1.9 ] . For each β , a parameterization of the stable manifold is computed and the symmetric homoclinic orbits are obtained by solving a projected boundary value problem using Chebyshev series. The proof is computer-assisted and combines the uniform contraction theorem and the radii polynomial approach, which provides an efficient means of determining a set, centered at a numerical approximation of a solution, on which a Newton-like operator is a contraction. [ABSTRACT FROM AUTHOR]

This meta-analysis is the first to our knowledge to evaluate the predictive properties of dynamic sex offender risk assessment instruments, which are designed to assess factors associated with recidivism that are amenable to change. Based on 52 studies (N = 13,446), we found that dynamic risk assessment instruments have small-to-moderate predictive properties, with Cohen's d ranging between 0.71 for sexual recidivism (41 studies, 22 unique samples, N = 5,699) and 0.43 for violent (including sexual) recidivism (27 studies, 14 unique samples, N = 10,368). Incremental predictive validity of dynamic over static risk assessment instruments was significant but modest; Cox hazard ratios varied between 1.08 for sexual recidivism (19 studies, 13 unique samples, N = 3,747) and 1.05 for any recidivism (11 studies, 8 unique samples, N = 2,511). Cox hazard ratios for the predictive validity of change scores on dynamic risk assessment instruments, controlling for static and initial dynamic scores, varied between 0.91 for sexual recidivism (6 studies, 6 unique samples, n = 1,980) and 0.95 for any recidivism (3 studies, 3 unique samples, n = 1,172). These findings indicate that dynamic risk assessment instruments can, in terms of Andrews and Bonta's (2010) risk and need principles, be a useful tool for improving sex offender treatment. They have the potential to contribute to the selection of appropriate, more individually tailored treatment approaches (focusing on individually relevant criminogenic need factors) and can assist in the evaluation of treatment effects. Considering this, further development of dynamic risk assessment instruments is warranted. (PsycINFO Database Record [ABSTRACT FROM AUTHOR]

Social media makes an important contribution to a rapidly changing world in which various domains of meaning are described anew. The evolving nature and dynamic character of social media therefore provides for a rich praxis terrain with which to interact from a practical theological orientation. More specifically associated with the theme of this contribution, the social media sphere also provides an excellent space not only to rethink but also to reenact expressions of dignity in society. The research is facilitated from a practical theological orientation, with particular focus on a normative dimension as embodied in aspects of dignity. Through the use of an interdisciplinary approach and methodology, some contours of dignity specifically associated with South African politics as well as the so-called Charlie Hebdo attacks in 2015 in Paris expressed on the social media platform, Twitter, are described and discussed. From this empirical analysis, description and discussion, a practical theological reflection is offered in which aspects of dignity associated with a normativity function are described. Some practical theological perspectives contributing to future relevant tweeting on dignity are also formulated and provided in conclusion. [ABSTRACT FROM AUTHOR]

The author discusses the diffusion of the works of the English deist Thomas Morgan in the U.S. He mentions that numerous intellectuals and deists report on seeing copies of Morgan's works in libraries and personal collections, as well as discussing the spread of deism throughout the country.

Objective We examined the costs and benefits of introducing migraine nurses into primary care. Background Migraine is one of the most costly neurological diseases. Methods We analyzed data from our earlier nonrandomized cohort study comparing an intervention group of 141 patients, whose care was supported by nurses trained in migraine management, and a control group of 94 patients receiving usual care. Estimates of per-person direct costs were based on nurses' salaries and referrals to neurologists. Indirect costs were estimated as lost productivity, including numbers of days of absenteeism or with <50% productivity at work due to migraine, and notional costs related to lost days of household activities or days of <50% household productivity. Analysis was conducted from the payer's perspective. Results After 9 months the direct costs were €281.11 in the control group against €332.23 in the intervention group (mean difference −51.12; 95% CI: −113.20-15.56; P = .134); the indirect costs were €1985.51 in the control group against €1631.75 in the intervention group (mean difference 353.75; 95% CI: −355.53-1029.82; P = .334); and total costs were €2266.62 in the control group, against €1963.99 in the intervention group (mean difference 302.64; 95% CI: −433.46-1001.27; P = .438). When costs attributable to lost household productivity were included, total costs increased to €6076.62 in the control group and €5048.15 in the intervention group (mean difference 1028.47; 95% CI: −590.26-2603.67; P = .219). Conclusion Migraine nurses in primary care seemed in this study to increase practice costs but decrease total societal costs. However, it was a nonrandomized study, and the differences did not reach significance. For policy-makers concerned with headache-service organization and delivery, the important messages are that we found no evidence that nurses increased overall costs, and investment in a definitive study would therefore be worthwhile. [ABSTRACT FROM AUTHOR]

An (auto)biographical Twitter-theology. Due to the increasing challenges created by an evolving digital world, traditional expressions of the Christian faith could become irrelevant for a fast-paced world. Through an autobiographical orientation, a search for meaningful personal expressions of the Christian faith on Twitter is traced and mapped down. Facilitated through a practical-theological inquiry and employing a qualitative empirical research methodology, personal aphorisms of the Christian faith on Twitter are traced down and presented as possible examples of a relevant digital autobiographical theology. Through the contribution of these empirical realities, new hermeneutical outcomes and a strategic involvement are facilitated. The creation, development and meaning of new theological formulations and articulations are explored and described through these expressions. In the tracing of and in the mapping down of these new expressions of faith, demarcations of a possible lived spirituality in the digital sphere are sounded out and verbalised. Through the documentation of these new and relevant articulations of the language of faith, a contribution is made to a meaningful digital autobiographical theology. [ABSTRACT FROM AUTHOR]

Most research in social networks has focused on the assumption that unknown entities are malicious and thus the traditional approach was to detect them and deny their access to sensitive data. In this paper, we propose a new computational model that helps users predict security risks associated with their information sharing on social networks. The model is based on the assumption that a risk indicator value can be predicted by assessing a number of risk attributes using a neuro-fuzzy technique. A disclosure decision is made based on this risk indicator value. The approach was tested in a real prototype of a social mobile service at a university campus. Further, we show how the model can be implemented in a popular social rating site. Results obtained show the relevance and effectiveness of the proposed approach in predicting risks and in deciding up on it about disclosure decisions in social pervasive applications. [ABSTRACT FROM AUTHOR]

In this work we introduce a rigorous computational method for finding heteroclinic solutions of a system of two second order differential equations. These solutions correspond to standing waves between rolls and hexagonal patterns of a two-dimensional pattern formation PDE model. After reformulating the problem as a projected boundary value problem (BVP) with boundaries in the stable/unstable manifolds, we compute the local manifolds using the parameterization method and solve the BVP using Chebyshev series and the radii polynomial approach. Our results settle a conjecture by Doelman et al. [European J. Appl. Math., 14 (2003), pp. 85-110] about the coexistence of hexagons and rolls. [ABSTRACT FROM AUTHOR]

Different and divergent facets of human existence are increasingly becoming embodied within a digital domain. The social media platform, Twitter, comprises an important expression of the digital world and social media, but also of popular culture. In a practical theological tracing of the theme of human waste on Twitter, new contents and meaning related to this concept are mapped out in a variety of categories. On the basis of existing and newly developed research methodologies, an exploration is conducted in order to indicate how the digital world can assist in the creation of new empirical realities, hermeneutic outcomes and strategic involvement. In this tracing of human waste as a theme on Twitter, accents of a possible lived spirituality are sounded out and verbalised. It is on the basis of these descriptions that possibilities unfold for new practical theological orientations, both for the present and the future. [ABSTRACT FROM AUTHOR]

Against the backdrop of a virtual existence, this contribution has portrayed the intimate relationship between two practical theologians. Through the use of biographical accounts, the author has not only attempted to indicate the significant contribution of Professor Julian Müller to the field of practical theology, but has also described the influence of this work on his own life and current research practice. In these descriptions of engagement, on the basis of which relevant research accents have been demarcated, a scenario pointing towards relevant future developments has also been indicated. In the mapping of a digital autobiographical practical theology, the author has personally 'reached beyond' in his endeavour to identify new research avenues in the articulation of the autobiographical language of a lived digital religion. [ABSTRACT FROM AUTHOR]

The phenomenon relating to the popularity and impact of social media as an important expression of the new digital world, is already widely known and well-documented. In this research, the main focus will fall on a specific manner of expression associated with social media and, in particular, with the Twitter platform, namely the hashtag (#) symbol. This symbol has come to comprise an important expression in popular culture, and is generally associated with various dimensions of activities in the social media environment. Through the use of several examples from the recent past, the development and meaning of the hashtag will be explored and described. As part of this description, a motivation will be put forward as to why it is important, for the purposes of a practical theological involvement as expressed in the dimensions of a lived spirituality, to take cognisance of the hashtag and the world that is associated with it. Arising from this motivation, and in congruence with the strategic character of practical theology, perspectives will be mapped out with a view to the further use and meaning of a dynamic reading of the hashtag. [ABSTRACT FROM AUTHOR]

In a digital world, it seems as if the boundaries between rich and poor are becoming increasingly blurred. A mobinomic world is created through the use of cellular telephones, which plays an important role on multiple levels of socioeconomic understanding. Various advantages are created through the interplay between the power of mobility and the convergence of various forms of media. Considering the immediate accessibility of an overflow of data in various forms as well as time pressure, decision-making is increasingly becoming associated with living in the fast lane of the digital world. Unfortunately, the cost of faster decision-making is that it could potentially result in individuals making poor decisions on various levels. A practical-theological exploration, as embedded in a transversal rational engagement, entails a preliminary investigation and description of this digital reality, especially as portrayed in the dynamics of decision-making associated with the social media platform Twitter. [ABSTRACT FROM AUTHOR]

Abstract: We develop and present a computational method for producing forcing theorems for stationary and periodic solutions and connecting orbits in scalar parabolic equations with periodic boundary conditions. This method is based on prior work by van den Berg, Ghrist, and Vandervorst on a Conley index theory for solutions braided through a collection of known stationary solutions. Essentially, the topological structure of the stationary solutions forces the existence of additional solutions with a specified topological type. In particular, this paper studies connecting orbits and develops and implements the algorithms required to compute the index, providing sample results as illustrations. [Copyright &y& Elsevier]

Abstract: In this paper we investigate periodic solutions of second order Lagrangian systems which oscillate around equilibrium points of center type. The main ingredients are the discretization of second order Lagrangian systems that satisfy the twist property and the theory of discrete braid invariants developed by Ghrist et al. (2003) . The problem with applying this topological theory directly is that the braid types in our analysis are so-called improper. This implies that the braid invariants do not entirely depend on the topology: the relevant braid classes are non-isolating neighborhoods of the flow, so that their Conley index is not universal. In first part of this paper we develop the theory of the braid invariant for improper braid classes and in the second part this theory is applied to second order Lagrangian system and in particular to the Swift–Hohenberg equation. [Copyright &y& Elsevier]

In the context of the interconnected world of the information age, and demarcated by a virtual existence through the use of the Internet, decision-making has become even more dynamic. In an evolving era of virtuality, with special emphasis on the increasing role of mobile communication technology, it is indicated that decision-making has become fluid. As part of the phenomenon of fluid decision-making, not only is the evolutionary character of virtual connectivity acknowledged, but the ever-increasing and important role of mobile platforms is also emphasised. In a hermeneutical practical theology of lived spirituality, focusing on the praxis of everyday living, the possible role of spirituality in informing the fluid decision-making processes in a mobile virtual world was traced. A qualitatively inspired analysis, using data collected from various virtual forums, was proposed. In the description of these contours, special emphasis was placed on narrative-inspired biographical accents. The research made a contribution in terms of possible new articulations of the language of faith as embodied in fluid decision-making in a mobile virtual reality. [ABSTRACT FROM AUTHOR]

Abstract: An important paradigm in decision-making models is utility-maximization where most models do not include actors’ motives. Fuzzy set theory on the other hand offers a method to simulate human decision-making. However, the literature describing expert-driven fuzzy logic models, rarely gives precise details on the methodology (to be) used. To fill the gap, this paper describes a methodology of 10 steps to model individual actor’s drivers, motives, hereby taking into account the ecological, social and economic context. Testing the methodology on the composition of mixed farming systems in the Mekong Delta, Vietnam, showed that manual model development is not a waterfall approach but requires feedback loops, except for model implementation. Using feed-back loops, the proposed 10 step method allowed to include human drivers and motives other than utility-maximization and to maintain a degree of transparency hard to achieve when using automated procedures. [Copyright &y& Elsevier]

In this paper we propose a rigorous numerical technique for the computation of symmetric connecting orbits for ordinary differential equations. The idea is to solve a projected boundary value problem (BVP) in a function space via a fixed point argument. The formulation of the projected BVP involves a high order parameterization of the invariant manifolds at the steady states. Using this parameterization, one can obtain explicit exponential asymptotic bounds for the coefficients of the expansion of the manifolds. Combining these bounds with piecewise linear approximations, one can construct a contraction in a function space whose unique fixed point corresponds to the wanted connecting orbit. We have implemented the method to demonstrate its effectiveness, and we have used it to prove the existence of a family of even homoclinic orbits for the Gray-Scott equation. [ABSTRACT FROM AUTHOR]

The article discusses a study on the effectiveness of dexamethasone in varying doses as an anti-inflammatory therapy during early sepsis in mice. The study procedure included the administration of dexamethasone in mice, cecal ligation and puncture, and the administration of phosphate-buffered saline. The researchers concluded that the success of anti-inflammatory therapies in a septic setting is associated to treatment balance.

In second order Lagrangian systems bifurcation branches of periodic solutions preserve certain topological invariants. These invariants are based on the observation that periodic orbits of a second order Lagrangian lie on 3-dimensional (noncompact) energy manifolds and the periodic orbits may have various linking and knotting properties. The main ingredients defining the topological invariants are the discretization of second order Lagrangian systems that satisfy the twist property and the theory of discrete braid invariants developed in [R. W. Ghrist, J. B. Van den Berg, and R. C. Vandervorst, Invent. Math., 152 (2003), pp. 369-432]. In the first part of this paper we recall the essential theory of braid invariants, and in the second part this theory is applied to second order Lagrangian systems and in particular to the Swift--Hohenberg equation. We show that the invariants yield forcing relations on bifurcation branches. We quantify this principle via an order relation on the topological type of a bifurcation branch. The order will then determine the forcing relation. It is shown that certain braid classes force infinitely many solution curves. [ABSTRACT FROM AUTHOR]

We study a combustion-radiation model which models premixed flames propagating in a gaseous mixture with inert dust. This model combines diffusion of mass and temperature with reaction at the flame front. We choose a free boundary model to describe the propagating flames and take a linearized approximation to model the radiation, but we keep a nonlinear reaction term which is temperature dependent. The radiative transfer of thermal energy emitted and absorbed by dust is modelled using the Eddington equation. We analyse the bifurcation diagram of the travelling wave solution curve. In a specific parameter plane, travelling waves are given by a single smooth curve which is parameterized by the flame temperature. [ABSTRACT FROM AUTHOR]

The article discusses an animal study on the impact of β-human chorionic gonadotropin-related peptide LGQV on cecal ligation and punctured-induced mortality and inflammation. The study made use of male C57BL/6 mice with sepsis. It found that the peptide can lower risk of mortality and inflammation.

Summary Three days of fasting protects mice against lethal renal ischemia-reperfusion (I/R) injury. We hypothesize that the protection imposed by fasting is mediated by increased levels of corticosterone, induced by the stress of food deprivation. C57Bl/6 mice were fasted for 3 days after which serum corticosterone levels were determined. Mice underwent a bilateral adrenalectomy (ADX). Ten days later, they were either fasted or given a corticosterone receptor antagonist while fasting. Bilateral renal I/R injury was induced by clamping the artery and vein of the left and right kidney simultaneously for 37 min. Survival and kidney function were determined. Fasting significantly increased corticosterone levels. Only 8% of the ADX mice which were fasted prior to I/R injury survived, whereas all sham-ADX operated mice survived I/R injury after fasting. After ADX and fasting, 70% of the mice subjected to sham I/R succumbed to the surgical procedure. After fasting with concomitant blockade of the glucocorticoid receptor all animals survived renal I/R. Three days of fasting protects against I/R injury and increases serum corticosterone levels. ADX renders mice incapable of withstanding subsequent abdominal surgery. Glucocorticoid receptor blockade does not interfere with the protective effects of fasting. Thus, the protection against renal I/R injury induced by preoperative fasting is mediated by corticosterone-independent mechanisms. [ABSTRACT FROM AUTHOR]

Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explanations for this correlation have focused on the ants' ecology, such as food resource distribution. However, many species have colonies with a single queen and workforces that grow over several orders of magnitude, and little is known about how a colony's organization, including recruitment methods, may change during its growth. After all, recruitment involves interactions between ants, and hence the size of the colony itself may influence which recruitment method is used-even if the ants' behavioural repertoire remains unchanged. Here we show using mathematical models that the observed correlation can also be explained by recognizing that failure rates in recruitment depend differently on colony size in various recruitment strategies. Our models focus on the build up of recruiter numbers inside colonies and are not based on optimality arguments, such as maximizing food yield. We predict that ant colonies of a certain size should use only one recruitment method (and always the same one) rather than a mix of two or more. These results highlight the importance of the organization of recruitment and how it is affected by colony size. Hence these results should also expand our understanding of ant ecology. [ABSTRACT FROM AUTHOR]

We study the existence of solutions homoclinic to a saddle centre in a family of singularly perturbed fourth order differential equations, originating from a water-wave model. Due to a reversibility symmetry, the occurrence of such embedded solitons is a codimension-1 phenomenon. By varying a parameter a countable family of solitary waves is found. We examine the asymptotic frequency at which this phenomenon of persistence in the singular limit occurs, by performing a refined Stokes line analysis. In the limit where the parameter tends to infinity, each Stokes line splits into a pair, and the contributions of these two Stokes lines cancel each other for a countable set of parameter values. More generally, we derive the full leading order asymptotics for the Stokes constant, which governs the (exponentially small) amplitude of the (minimal) oscillations in the tails of nearly homoclinic solutions. True homoclinic trajectories are characterized by the Stokes constant vanishing. This formal asymptotic analysis is supplemented with numerical calculations. [ABSTRACT FROM AUTHOR]

While there is no consensus on a definition, it is widely recognized that the concept of sustainability has economic, environmental and social dimensions. We used fuzzy logic as a well-suited tool to handle the vague, uncertain, and polymorphous concept of sustainability. For recognizing the major important indicators in defining sustainability in range management, several semi-structured interviews with an open-ended questionnaire in three different areas of the Fars province in Southwest Iran were held. Pastoralists’ experts recognized that sustainability in range management is a function of three major components (inputs) which are the stocking rate in a pasture, the amount of plantation density per hectare, and the number of pastoralists who live in a pasture where the output of the model is the Right Rate of Stocking. Based on pastoralists’ insights we developed a model called Equilibrium Assessment by Fuzzy Logic (EAFL) which provides a mechanism for assessing sustainability in rangeland management. The EAFL model exhibits three important characteristics. First, it permits the combination of various aspects of sustainability with different units of measurement. Second, it overcomes the difficulty of assessing certain attributes or indicators of sustainability without precise quantitative criteria and, third, the methodology is easy to use and interpret. An important outcome of the EAFL model is that all the pastoralists’ experts agree with this conclusion that the current, real stocking rates are much higher than the optimal stocking rates. [Copyright &y& Elsevier]

We prove that the stationary Swift-Hohenberg equation has chaotic dynamics on a critical energy level for a large (continuous) range of parameter values. The first step of the method relies on a computer assisted, rigorous, continuation method to prove the existence of a periodic orbit with certain geometric properties. The second step is topological: we use this periodic solution as a skeleton, through which we braid other solutions, thus forcing the existence of infinitely many braided periodic orbits. A semiconjugacy to a subshift of finite type shows that the dynamics is chaotic. [ABSTRACT FROM AUTHOR]

About 30% of the potato plants from a ( Solanum tuberosum × S. berthaultii) × S. tuberosum backcross population had chlorotic, malformed leaves; but a gradation in symptom severity suggested regulation by more than one gene. The study was undertaken to determine whether this was the case, whether any genes previously reported to control chlorosis in potato were involved, and to see how symptoms were related to effects on chlorophyll content. Testing for quantitative trait loci indicated major control by a single recessive gene on chromosome 1, close to one or more loci that have been reported to produce chlorosis in tomato, but distinct from similar genes previously identified in potato. The proposed symbol for the potato gene that confers phenotype with chlorotic and malformed leaves is cml (chlorotic and malformed leaves). The effects of this gene appeared to be accentuated by a second gene, located on chromosome 12. Chlorotic plants showed a 50% decrease in chlorophyll b level in the affected parts of leaves. It is concluded that cml is different from previously reported genes for chlorosis in potato, that at least one other gene modifies the intensity of symptom expression, and that the observed chlorosis is produced through effects on chlorophyll b level. [ABSTRACT FROM AUTHOR]

The work of the English Deist Thomas Morgan (d. 1743), a Marcion in his time, received much negative criticism in England and abroad, especially in Germany. His views aroused comments in books, dissertations and journals. Only in the first half of the twentieth century was he to be praised by theologians such as Adolf von Harnack and Emanuel Hirsch, who likewise disparaged the Old Testament. [ABSTRACT FROM AUTHOR]

Symptoms of nocturnal hypoventilation may negatively influence the quality of life (QoL) of ALS patients long before respiratory failure ensues. Non‐invasive mechanical ventilation (NIV) is considered a treatment option for nocturnal hypoventilation. The primary objective of NIV is improving quality of life (QoL). It may also prolong life by several months. A systematic review of the literature was performed to analyse what is known of the effect of NIV on survival, QoL and other outcome measures. A computerized literature search was performed to identify controlled clinical trials and observational studies of treatment of ALS‐associated nocturnal hypoventilation from 1985 until May 2005. Twelve studies fulfilled the inclusion criteria. Four studies were retrospective, seven prospective and in one study randomization was used. All studies reported beneficial effects of NIV on all outcome measures. In seven studies NIV was associated with prolonged survival in patients tolerant for NIV, and five studies reported an improved QoL. In conclusion, studies on the use of NIV in ALS differ in study design and endpoint definitions. All studies suggest a beneficial effect on QoL and other outcome measures (Evidence level Class II‐III). Well‐designed randomized controlled trials comparing the effect on QoL and survival have not been performed. [ABSTRACT FROM AUTHOR]

We study radial flame ball solutions of a three-dimensional free boundary problem (FBP), which models combustion of a gaseous mixture with dust in a microgravity environment. The model combines diffusion of mass and temperature with reaction at the flame front, the reaction rate being temperature dependent. The radiative flux due to the presence of dust enters the equation for the temperature in the form of a divergence term. This flux is modeled by Eddington's radiative transfer equation. The main parameters are the dimensionless opacity and the ratio of radiative and thermal fluxes. We prove existence of spherical flame ball solutions for the FBP. Bifurcation diagrams are obtained, exhibiting the multiplicity of solutions. Singular limit cases of the parameter values are also discussed. [ABSTRACT FROM AUTHOR]

We study a thermodiffusive combustion model for premixed flames propagating in reactive gaseous mixtures which contain inert dust. As observed by Joulin, radiative transfer of heat may significantly enhance the flame temperature and its propagation speed. The Joulin effect is at its most pronounced in the parameter regime where the medium is very transparent while radiative flux dominates convection. In this asymptotic regime, where in the limit the flame temperature achieves its upper bound, we determine the law that describes the relation between the propagation speed of the flame and the control parameters. Finally, we present strong numerical evidence for the validity of the asymptotic analysis. [ABSTRACT FROM AUTHOR]

van den Berg JWK, Slebos D-J, Postma DS, Dijkhuizen B, Koëter GH, Timens W, van der Bij W, Kauffman HF. Feasibility of sputum induction in lung transplant recipients. Clin Transplant 2004 DOI: 10.1111/j.1399-0012.2004.00237.x © Blackwell Munksgaard, 2004 Sputum induction (SI) is nowadays being applied as a non-invasive and safe method to investigate airway inflammation in pulmonary diseases. We investigated the feasibility of SI after lung transplantation (LTX), and compared sputum and bronchoalveolar lavage (BAL) cellular characteristics and interleukin-8 (IL-8) levels. Results were also compared with 11 healthy subjects. SI as performed between 26 and 1947 d after LTX in 19 recipients, was successful in 16 of 22 attempts (73%). Six patients failed to produce sputum after induction, mostly just post-LTX and with having a lower forced expiratory volume in 1 s (FEV1). The success rate in clinically stable patients after the first month post-LTX was 93%. Side-effects were absent. Sputum recovery, viability and squamous cell contamination were comparable between LTX patients and healthy subjects. In the LTX group, total cell counts, neutrophil percentages and IL-8 levels were much higher in SI than BAL (1.6 × 106/mL, 65.5% and 54.2 ng/mL vs. 0.1 × 106/mL, 3.0% and 0.01 ng/mL; p < 0.001). Although LTX-neutrophil percentages in SI and BAL correlated properly ( ρ = 0.72, p = 0.04), both techniques are not interchangeable. We conclude that sputum induction is feasible, well tolerated, and without major side-effects in stable patients after the first month post-LTX. Induced sputum may be a useful tool to study inflammatory changes of the airways after LTX, and because of the large quantity of neutrophils sampled, especially for further studies on the pathogenesis of bronchiolitis obliterans. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the Netherlands, rehabilitation medicine plays an important role in the symptomatic and palliative treatment of ALS patients. Detailed information about the actual care of ALS patients in the Netherlands and about the attitude of consultants in rehabilitation medicine towards the management of this disease was lacking. OBJECTIVE: To obtain detailed information about the rehabilitation care for patients with ALS in the Netherlands. METHODS: We have performed a survey among all consultants in rehabilitation medicine in the Netherlands, using a questionnaire about the organisation of care and the care management of ALS patients. RESULTS: Two hundred eighty one questionnaires were gathered with a response rate of 98%. There were 14 specialised ALS centres spread throughout the country, except in the northwest and southwest. Most consultants worked with an ALS multidisciplinary team and most patients were treated in an outpatient rehabilitation clinic. Follow up visits were performed in most cases 5-6 times per year. The majority of the patients were followed up until death. The Dutch protocol for rehabilitative management in ALS was used in 89% of all treated ALS patients. Follow up and care management was not different in the specialised centres compared with the non-specialised centres. CONCLUSION: In conclusion, this study indicated that the actual care for ALS patients was reasonably well organised in the Netherlands, based on the results and reactions of the consultants in rehabilitation medicine. [ABSTRACT FROM AUTHOR]

Abstract Natural, moderately loosely packed sands can only erode from the surface of the bed after an increase in pore volume. Because of this shear dilatancy, negative pore pressures are generated in the bed. In cases of low permeability, these negative pressures are released relatively slowly, which retards the maximum rate of erosion. This effect is incorporated in a new, analytically derived, pick-up function that can explain the observation of gradual retrogressive failure of very steep subaqueous slopes, sometimes more than 5 m high, in fine non-cohesive sands. This process, termed ‘breaching’ in the field of sediment dredging, may produce large failures in sand bars or river banks. The analytical function that describes the breaching process in fine sand is incorporated in a one-dimensional, steady-state numerical model of turbidity currents describing the spatial development of flow. This model is applied to simulate a large ‘flushing’ event in Scripps Submarine Canyon, Pacific coast of California. Breach retrogradation and the successive evolution in time of the resulting turbidity current in the canyon are predicted in a sequence of discrete steps. Predicted velocities are compared with values measured during a flushing event. Implications for the interpretation of deep-water massive sands are discussed. [ABSTRACT FROM AUTHOR]

We establish the existence of homoclinic solutions for a class of fourth-order equations which includes the Swift–Hohenberg model and the suspension bridge equation. In the first case, the nonlinearity has three zeros, corresponding to a double-well potential, while in the second case the nonlinearity is asymptotically constant on one side. The Swift–Hohenberg model is a higher-order extension of the classical Fisher–Kolmogorov model. Its more complicated dynamics give rise to further possibilities of pattern formation. The suspension bridge equation was studied by Chen and McKenna (J. Differential Equations136 (1997), 325–355); we give a positive answer to an open question raised by the authors. [Copyright &y& Elsevier]