Multivariate Anisotropic Interpolation on the Torus

We investigate the error of periodic interpolation, when sampling a function on an arbitrary pattern on the torus. We generalize the periodic Strang-Fix conditions to an anisotropic setting and provide an upper bound for the error of interpolation. These conditions and the investigation of the error especially take different levels of smoothness along certain directions into account

Udvalgte Stykker af Læren om Jordbunden.

Udvalgte Stykker af Læren om Jordbunden

Om Ammoniak og Ammoniaksaltene, isærdeleshed om det Værd, som disse have til Vegetationens Befordring.

Om Ammoniak og Ammoniaksaltene, isærdeleshed om det Værd, som disse have til Vegetationens Befordring

Comparison of different CT metal artifact reduction strategies for standard titanium and carbon-fiber reinforced polymer implants in sheep cadavers

BACKGROUND CT artifacts induced by orthopedic implants can limit image quality and diagnostic yield. As a number of different strategies to reduce artifact extent exist, the aim of this study was to systematically compare ex vivo the impact of different CT metal artifact reduction (MAR) strategies on spine implants made of either standard titanium or carbon-fiber-reinforced-polyetheretherketone (CFR-PEEK). METHODS Spine surgeons fluoroscopically-guided prepared six sheep spine cadavers with pedicle screws and rods of either titanium or CFR-PEEK. Samples were subjected to single- and dual-energy (DE) CT-imaging. Different tube voltages (80, DE mixed, 120 and tin-filtered 150 kVp) at comparable radiation dose and iterative reconstruction versus monoenergetic extrapolation (ME) techniques were compared. Also, the influence of image reconstruction kernels (soft vs. bone tissue) was investigated. Qualitative (Likert scores) and quantitative parameters (attenuation changes induced by implant artifact, implant diameter and image noise) were evaluated by two independent radiologists. Artifact degree of different MAR-strategies and implant materials were compared by multiple ANOVA analysis. RESULTS CFR-PEEK implants induced markedly less artifacts than standard titanium implants (p < .001). This effect was substantially larger than any other tested MAR technique. Reconstruction algorithms had small impact in CFR-PEEK implants and differed significantly in MAR efficiency (p < .001) with best MAR performance for DECT ME 130 keV (bone kernel). Significant differences in image noise between reconstruction kernels were seen (p < .001) with minor impact on artifact degree. CONCLUSIONS CFR-PEEK spine implants induce significantly less artifacts than standard titanium compositions with higher MAR efficiency than any alternate scanning or image reconstruction strategy. DECT ME 130 keV image reconstructions showed least metal artifacts. Reconstruction kernels primarily modulate image noise with minor impact on artifact degree

Distinct effects of AMPAR subunit depletion on spatial memory

Pharmacological studies established a role for AMPARs in the mammalian forebrain in spatial memory performance. Here we generated global GluA1/3 double knockout mice (Gria1/3−/−) and conditional knockouts lacking GluA1 and GluA3 AMPAR subunits specifically from principal cells across the forebrain (Gria1/3ΔFb). In both models, loss of GluA1 and GluA3 resulted in reduced hippocampal GluA2 and increased levels of the NMDAR subunit GluN2A. Electrically-evoked AMPAR-mediated EPSPs were greatly diminished, and there was an absence of tetanus-induced LTP. Gria1/3−/− mice showed premature mortality. Gria1/3ΔFb mice were viable, and their memory performance could be analyzed. In the Morris water maze (MWM), Gria1/3ΔFb mice showed profound long-term memory deficits, in marked contrast to the normal MWM learning previously seen in single Gria1−/− and Gria3−/− knockout mice. Our results suggest a redundancy of function within the pool of available ionotropic glutamate receptors for long-term spatial memory performance

FINITUDE HUMANA E ENFERMAGEM: REFLEXÕES SOBRE O (DES)CUIDADO INTEGRAL E HUMANIZADO AO PACIENTE E SEUS FAMILIARES DURANTE O PROCESSO DE MORRER

This paper presents a reflection about nurse care to the patient and its relatives face the death. It focuses the integral and humanized care and aims to touch nursing team and others health professionals about the necessity to attend the human, as bio-psycho-social, cultural and spiritual being. Focalizes the death as the unique certainty that one have since was born, sometimes crossed by many denying mechanism, since for the occidental society is common to deny the finitude instead to accept it. It shows that the nurse care to the patients and relatives face to death process, demand technical efficiency, sensibility and interaction, manifesting the art of nursing as an empathy, intuition and perception to attend patient and its relative’s needs. At same time must respect the expression of pain, aguish, abandon, loose, desperate, anger and others frequently observed on process of die. This paper wants to contribute to touch health workers, especially nurses and to emphasize the value of integral and humanized care. It also point out the necessity to discuss this subject during the graduation.Este articulo muestra una reflexión sobre el cuidado de enfermería dado a los enfermos y a su familia frente a la muerte. Enfoca el cuidado general y humanizado y busca sensibilizar el equipo de enfermería y demás profesionales del equipo de salud, frente a la necesidad de una atención adecuada al ser humano, viéndolo como un ser biopisicosocial, cultural y espiritual. Enfoca la muerte como el único hecho real que se tiene desde el nacimiento, rodeado sin embargo, por diversos mecanismos de negación por parte del enfermo y de sus familiares y hasta por los mismos profesionales que lo atienden, pues, para el hombre occidental es común negar su finitud en vez de aceptarla. Muestra que la atención de enfermería dado al enfermo y su familia frente al proceso de muerte, requiere del enfermero eficiencia técnico – científico, sensibilidad y acogimiento, mostrando el arte de la enfermería como el sentir, intuición, percepción aguda para atender las necesidades del enfermo y su familia. Debe también respetar la expresión de sentimientos de dolor, angustia, agresividad, abandono, perdida, desespero, rabia, culpa, entre otros, que a menudo son observados en el transcurso del proceso de muerte. Frente a estas constataciones este estudio pretende contribuir para la sensibilización de los profesionales de salud y en especial para los de enfermería y enfatizar la importancia del cuidado general y humanizado al enfermo y a su familia. Busca también resaltar la necesidad de un abordaje del tema durante la formación de los profesionales de salud.O artigo apresenta uma reflexão sobre o cuidado de enfermagem ao paciente e seus familiares diante da morte. Enfoca o cuidado integral e humanizado e visa à sensibilização da equipe de enfermagem e demais profissionais da equipe de saúde quanto à necessidade de um atendimento adequado ao ser humano, compreendido como um ente biopsicossocial, cultural e espiritual. Focaliza a morte como a única certeza que se tem desde o nascimento, permeada, porém, por diversos mecanismos de negação por parte do paciente e de seus familiares e até mesmo dos profissionais que o assistem, pois para o homem ocidental é corrente negar a sua finitude ao invés de aceitá-la. Evidencia que o cuidado de enfermagem prestado a pacientes e familiares diante do processo de morrer requer do enfermeiro eficiência técnico-científica, sensibilidade e interação, manifestando a arte da enfermagem como a empatia, intuição, percepção aguçada para atender às necessidades do paciente e de seus familiares. Deve, igualmente, respeitar a expressão dos sentimentos de dor, angústia, agressividade, abandono, perda, desespero, raiva, culpa, entre outros freqüentemente observados no transcorrer da vivência do processo de morrer. Diante destas constatações, este trabalho pretende contribuir para a sensibilização dos profissionais de saúde e, em especial, os da enfermagem e enfatizar a importância do cuidado integral e humanizado ao paciente, compartilhado com os familiares. Pretende ressaltar, também, a necessidade de abordagem do tema no decorrer da formação dos profissionais de saúde

Glutamatergic dysfunction leads to a hyper-dopaminergic phenotype through deficits in short-term habituation: a mechanism for aberrant salience

Psychosis in disorders like schizophrenia is commonly associated with aberrant salience and elevated striatal dopamine. However, the underlying cause(s) of this hyper-dopaminergic state remain elusive. Various lines of evidence point to glutamatergic dysfunction and impairments in synaptic plasticity in the etiology of schizophrenia, including deficits associated with the GluA1 AMPAR subunit. GluA1 knockout (Gria1−/−) mice provide a model of impaired synaptic plasticity in schizophrenia and exhibit a selective deficit in a form of short-term memory which underlies short-term habituation. As such, these mice are unable to reduce attention to recently presented stimuli. In this study we used fast-scan cyclic voltammetry to measure phasic dopamine responses in the nucleus accumbens of Gria1−/− mice to determine whether this behavioral phenotype might be a key driver of a hyper-dopaminergic state. There was no effect of GluA1 deletion on electrically-evoked dopamine responses in anaesthetized mice, demonstrating normal endogenous release properties of dopamine neurons in Gria1−/− mice. Furthermore, dopamine signals were initially similar in Gria1−/− mice compared to controls in response to both sucrose rewards and neutral light stimuli. They were also equally sensitive to changes in the magnitude of delivered rewards. In contrast, however, these stimulus-evoked dopamine signals failed to habituate with repeated presentations in Gria1−/− mice, resulting in a task-relevant, hyper-dopaminergic phenotype. Thus, here we show that GluA1 dysfunction, resulting in impaired short-term habituation, is a key driver of enhanced striatal dopamine responses, which may be an important contributor to aberrant salience and psychosis in psychiatric disorders like schizophrenia