115 research outputs found

    Uniform Continuity and Br\'ezis-Lieb Type Splitting for Superposition Operators in Sobolev Space

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    Using concentration-compactness arguments we prove a variant of the Brezis-Lieb-Lemma under weaker assumptions on the nonlinearity than known before. An intermediate result on the uniform continuity of superposition operators in Sobolev space is of independent interest

    Alternating sign multibump solutions of nonlinear elliptic equations in expanding tubular domains

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    Let Γ\Gamma denote a smooth simple curve in RN\mathbb{R}^{N}, N≥2N\geq2, possibly with boundary. Let ΩR\Omega_{R} be the open normal tubular neighborhood of radius 1 of the expanded curve RΓ:={Rx∣x∈Γ∖∂Γ}R\Gamma:=\{Rx\mid x\in \Gamma\smallsetminus\partial\Gamma\}. Consider the superlinear problem −Δu+λu=f(u)-\Delta u+\lambda u=f(u) on the domains ΩR\Omega_{R}, as R→∞R\rightarrow \infty, with homogeneous Dirichlet boundary condition. We prove the existence of multibump solutions with bumps lined up along RΓR\Gamma with alternating signs. The function ff is superlinear at 0 and at ∞\infty, but it is not assumed to be odd. If the boundary of the curve is nonempty our results give examples of contractible domains in which the problem has multiple sign changing solutions

    Boundary clustered layers near the higher critical exponents

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    We consider the supercritical problem {equation*} -\Delta u=|u| ^{p-2}u\text{\in}\Omega,\quad u=0\text{\on}\partial\Omega, {equation*} where Ω\Omega is a bounded smooth domain in RN\mathbb{R}^{N} and pp smaller than the critical exponent 2N,k∗:=2(N−k)N−k−22_{N,k}^{\ast}:=\frac{2(N-k)}{N-k-2} for the Sobolev embedding of H1(RN−k)H^{1}(\mathbb{R}^{N-k}) in Lq(RN−k)L^{q}(\mathbb{R}^{N-k}), 1≤k≤N−3.1\leq k\leq N-3. We show that in some suitable domains Ω\Omega there are positive and sign changing solutions with positive and negative layers which concentrate along one or several kk-dimensional submanifolds of ∂Ω\partial\Omega as pp approaches 2N,k∗2_{N,k}^{\ast} from below. Key words:Nonlinear elliptic boundary value problem; critical and supercritical exponents; existence of positive and sign changing solutions

    A concentration phenomenon for semilinear elliptic equations

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    For a domain \Omega\subset\dR^N we consider the equation -\Delta u + V(x)u = Q_n(x)\abs{u}^{p-2}u with zero Dirichlet boundary conditions and p∈(2,2∗)p\in(2,2^*). Here V≥0V\ge 0 and QnQ_n are bounded functions that are positive in a region contained in Ω\Omega and negative outside, and such that the sets {Qn>0}\{Q_n>0\} shrink to a point x0∈Ωx_0\in\Omega as n→∞n\to\infty. We show that if unu_n is a nontrivial solution corresponding to QnQ_n, then the sequence (un)(u_n) concentrates at x0x_0 with respect to the H1H^1 and certain LqL^q-norms. We also show that if the sets {Qn>0}\{Q_n>0\} shrink to two points and unu_n are ground state solutions, then they concentrate at one of these points

    MusMorph, a database of standardized mouse morphology data for morphometric meta-analyses.

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    Complex morphological traits are the product of many genes with transient or lasting developmental effects that interact in anatomical context. Mouse models are a key resource for disentangling such effects, because they offer myriad tools for manipulating the genome in a controlled environment. Unfortunately, phenotypic data are often obtained using laboratory-specific protocols, resulting in self-contained datasets that are difficult to relate to one another for larger scale analyses. To enable meta-analyses of morphological variation, particularly in the craniofacial complex and brain, we created MusMorph, a database of standardized mouse morphology data spanning numerous genotypes and developmental stages, including E10.5, E11.5, E14.5, E15.5, E18.5, and adulthood. To standardize data collection, we implemented an atlas-based phenotyping pipeline that combines techniques from image registration, deep learning, and morphometrics. Alongside stage-specific atlases, we provide aligned micro-computed tomography images, dense anatomical landmarks, and segmentations (if available) for each specimen (N = 10,056). Our workflow is open-source to encourage transparency and reproducible data collection. The MusMorph data and scripts are available on FaceBase ( www.facebase.org , https://doi.org/10.25550/3-HXMC ) and GitHub ( https://github.com/jaydevine/MusMorph )

    The cross-sectional GRAS sample: A comprehensive phenotypical data collection of schizophrenic patients

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    <p>Abstract</p> <p>Background</p> <p>Schizophrenia is the collective term for an exclusively clinically diagnosed, heterogeneous group of mental disorders with still obscure biological roots. Based on the assumption that valuable information about relevant genetic and environmental disease mechanisms can be obtained by association studies on patient cohorts of ≥ 1000 patients, if performed on detailed clinical datasets and quantifiable biological readouts, we generated a new schizophrenia data base, the GRAS (Göttingen Research Association for Schizophrenia) data collection. GRAS is the necessary ground to study genetic causes of the schizophrenic phenotype in a 'phenotype-based genetic association study' (PGAS). This approach is different from and complementary to the genome-wide association studies (GWAS) on schizophrenia.</p> <p>Methods</p> <p>For this purpose, 1085 patients were recruited between 2005 and 2010 by an invariable team of traveling investigators in a cross-sectional field study that comprised 23 German psychiatric hospitals. Additionally, chart records and discharge letters of all patients were collected.</p> <p>Results</p> <p>The corresponding dataset extracted and presented in form of an overview here, comprises biographic information, disease history, medication including side effects, and results of comprehensive cross-sectional psychopathological, neuropsychological, and neurological examinations. With >3000 data points per schizophrenic subject, this data base of living patients, who are also accessible for follow-up studies, provides a wide-ranging and standardized phenotype characterization of as yet unprecedented detail.</p> <p>Conclusions</p> <p>The GRAS data base will serve as prerequisite for PGAS, a novel approach to better understanding 'the schizophrenias' through exploring the contribution of genetic variation to the schizophrenic phenotypes.</p
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