6,443 research outputs found
A model for Hopfions on the space-time S^3 x R
We construct static and time dependent exact soliton solutions for a theory
of scalar fields taking values on a wide class of two dimensional target
spaces, and defined on the four dimensional space-time S^3 x R. The
construction is based on an ansatz built out of special coordinates on S^3. The
requirement for finite energy introduces boundary conditions that determine an
infinite discrete spectrum of frequencies for the oscillating solutions. For
the case where the target space is the sphere S^2, we obtain static soliton
solutions with non-trivial Hopf topological charges. In addition, such hopfions
can oscillate in time, preserving their topological Hopf charge, with any of
the frequencies belonging to that infinite discrete spectrum.Comment: Enlarged version with the time-dependent solutions explicitly given.
One reference and two eps figures added. 14 pages, late
Beyond the mask of deference: Exploring the relationship between ruptures and transference in a single-case study
Like grandparents, like parents: Empirical evidence and psychoanalytic thinking on the transmission of parenting styles
The authors discuss the issue of intergenerational transmission of parenting from an empirical and psychoanalytic perspective. After presenting a framework to explain their conception of parenting, they describe intergenerational transmission of parenting as a key to interpreting and eventually changing parenting behaviors. Then they present (1) the empirical approach aimed at determining if there is actually a stability across generations that contributes to harsh parenting and eventually maltreatment and (2) the psyphoanalytic thinking that seeks to explain the continuity in terms of representations and clinical phenomena. The authors also discuss the relationship between the attachment and the caregiving systems and hypothesize a common base for the two systems in childhood experience. Finally, they propose the psychoanalytic perspective as a fruitful theoretical framework to integrate the evidence for the neurophysiological mediators and moderators of intergenerational transmission. Psychoanalytically informed research can provide clinically relevant insights and hypotheses to be tested
Epiluminescence microscopy for the diagnosis of doubtful melanocytic skin lesions: Comparison of the ABCD rule of dermatoscopy and a new 7-point checklist based on pattern analysis
Objective: To compare the reliability of a new 7-point checklist based on simplified epiluminescence microscopy (ELM) pattern analysis with the ABCD rule of dermatoscopy and standard pattern analysis for the diagnosis of clinically doubtful melanocytic skin lesions. Design: In a blind study, ELM images of 342 histologically proven melanocytic skin lesions were evaluated for the presence of 7 standard criteria that we called the 'ELM 7-point checklist.' For each lesion, 'overall' and 'ABCD scored' diagnoses were recorded. From a training set of 57 melanomas and 139 atypical non-melanomas, odds ratios were calculated to create a simple diagnostic model based on identification of major and minor criteria for the '7-point scored' diagnosis. A test set of 60 melanomas and 86 atypical non-melanomas was used for model validation and was then presented to 2 less experienced ELM observers, who recorded the ABCD and 7-point scored diagnoses. Settings: University medical centers. Patients: A sample of patients with excised melanocytic lesions. Main Outcome Measures: Sensitivity, specificity, and accuracy of the models for diagnosing melanoma. Results: From the total combined sets, the 7-point checklist gave a sensitivity of 95% and a specificity of 75% compared with 85% sensitivity and 66% specificity using the ABCD rule and 91% sensitivity and 90% specificity using standard pattern analysis (overall ELM diagnosis). Compared with the ABCD rule, the 7-point method allowed less experienced observers to obtain higher diagnostic accuracy values. Conclusions: The ELM 7-point checklist provides a simplification of standard pattern analysis because of the low number of features to identify and the scoring diagnostic system. As with the ABCD rule, it can be easily learned and easily applied and has proven to be reliable in diagnosing melanoma
Soma térmica de fases de desenvolvimento de cultivares de arroz irrigado em função da época de semeadura.
O desenvolvimento da planta de arroz é afetado pela temperatura do ar e assim, a influência da temperatura nos processos de desenvolvimento vegetal pode ser expressa pela soma térmica, com unidade graus dia (ºC dia). O objetivo deste trabalho foi determinar a soma térmica de fases de desenvolvimento de quatro cultivares de arroz em três épocas de cultivo. Foi conduzido um experimento na área de várzea do Departamento de Fitotecnia da Universidade Federal de Santa Maria com três datas de semeadura (17/10/2011, 18/11/2011 e 19/12/2011) e quatro cultivares de ciclos distintos: IRGA 421 (ciclo superprecoce), BRS Querência (ciclo precoce), IRGA 424 (ciclo médio) e SCSBRS Tio Taka (ciclo tardio). A duração (º C dia) da fase de emergência - diferenciação de panícula aumentou com o atraso da data de semeadura, enquanto a duração da fase antese ? início da maturação dos grãos foi similar entre as cultivares semeadas no período recomendado pelo zoneamento agrícola
Sedimentology, structure and age estimate of five continental slope submarine landslides, eastern Australia
Sedimentological and accelerator mass spectrometry (AMS) <sup>14</sup>C data provide estimates of the structure and age of five submarine landslides (∼0.4–3 km<sup>3</sup>) present on eastern Australia's continental slope between Noosa Heads and Yamba. Dating of the post-slide conformably deposited sediment indicates sediment accumulation rates between 0.017 m ka<sup>–1</sup> and 0.2 m ka<sup>–1</sup>, which is consistent with previous estimates reported for this area. Boundary surfaces were identified in five continental slope cores at depths of 0.8 to 2.2 m below the present-day seafloor. Boundary surfaces present as a sharp colour-change across the surface, discernible but small increases in sediment stiffness, a slight increase in sediment bulk density of 0.1 g cm<sup>–3</sup>, and distinct gaps in AMS <sup>14</sup>C ages of at least 25 ka. Boundary surfaces are interpreted to represent a slide plane detachment surface but are not necessarily the only ones or even the major ones. Sub-bottom profiler records indicate that: (1) the youngest identifiable sediment reflectors upslope from three submarine landslides terminate on and are truncated by slide rupture surfaces; (2) there is no obvious evidence for a post-slide sediment layer draped over, or burying, slide ruptures or exposed slide detachment surfaces; and (3) the boundary surfaces identified within the cores are unlikely to be near-surface slide surfaces within an overall larger en masse dislocation. These findings suggest that these submarine landslides are geologically recent (<25 ka), and that the boundary surfaces are either: (a) an erosional features that developed after the landslide, in which case the boundary surface age provides a minimum age for the landslide; or (b) detachment surfaces from which slabs of near-surface sediment were removed during landsliding, in which case the age of the sediment above the boundary surface indicates the approximate age of landsliding. While an earthquake-triggering mechanism is favoured for the initiation of submarine landslides on the eastern Australian margin, further evidence is required to confirm this interpretation
Determinação do número de dias e dos graus-dia em que a iniciação da panícula (IP) antecede a diferenciação da panícula (DP) de cultivares de arroz irrigado.
Amending entanglement-breaking channels via intermediate unitary operations
We report a bulk optics experiment demonstrating the possibility of restoring the entanglement distribution through noisy quantum channels by inserting a suitable unitary operation (filter) in the middle of the transmission process. We focus on two relevant classes of single-qubit channels consisting in repeated applications of rotated phase-damping or rotated amplitude-damping maps, both modeling the combined Hamiltonian and dissipative dynamics of the polarization state of single photons. Our results show that interposing a unitary filter between two noisy channels can significantly improve entanglement transmission. This proof-of-principle demonstration could be generalized to many other physical scenarios where entanglement-breaking communication lines may be amended by unitary filters
Textile sustainability: reuse of clean waste from the textile and apparel industry
Today societies are already experiencing changes in their production systems and even consumption in order to guarantee the survival and well-being of future generations. This fact emerges from the need to adopt a more sustainable posture in both people's daily lives and productive systems. Within this context, textile sustainability emerges as the object of study of this work whose aim is to analyse which sustainability dimensions are being prioritized by the clean waste management systems of the textile and garment industries. This article aims to analyse solutions that are being proposed by sustainable creative business models in the reuse of discarded fabrics by the textile industry. Search also through a qualitative research by a case study (the Reuse Fabric Bank) understand the benefits generated by the re-use in environmental, economic, social and ways to add value.This work is supported by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT - Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136.info:eu-repo/semantics/publishedVersio
Performance deficits of NK1 receptor knockout mice in the 5 choice serial reaction time task: effects of d Amphetamine, stress and time of day.
Background
The neurochemical status and hyperactivity of mice lacking functional substance P-preferring NK1 receptors (NK1R-/-) resemble abnormalities in Attention Deficit Hyperactivity Disorder (ADHD). Here we tested whether NK1R-/- mice express other core features of ADHD (impulsivity and inattentiveness) and, if so, whether they are diminished by d-amphetamine, as in ADHD. Prompted by evidence that circadian rhythms are disrupted in ADHD, we also compared the performance of mice that were trained and tested in the morning or afternoon.
Methods and Results
The 5-Choice Serial Reaction-Time Task (5-CSRTT) was used to evaluate the cognitive performance of NK1R-/- mice and their wildtypes. After training, animals were tested using a long (LITI) and a variable (VITI) inter-trial interval: these tests were carried out with, and without, d-amphetamine pretreatment (0.3 or 1 mg/kg i.p.). NK1R-/- mice expressed greater omissions (inattentiveness), perseveration and premature responses (impulsivity) in the 5-CSRTT. In NK1R-/- mice, perseveration in the LITI was increased by injection-stress but reduced by d-amphetamine. Omissions by NK1R-/- mice in the VITI were unaffected by d-amphetamine, but premature responses were exacerbated by this psychostimulant. Omissions in the VITI were higher, overall, in the morning than the afternoon but, in the LITI, premature responses of NK1R-/- mice were higher in the afternoon than the morning.
Conclusion
In addition to locomotor hyperactivity, NK1R-/- mice express inattentiveness, perseveration and impulsivity in the 5-CSRTT, thereby matching core criteria for a model of ADHD. Because d-amphetamine reduced perseveration in NK1R-/- mice, this action does not require functional NK1R. However, the lack of any improvement of omissions and premature responses in NK1R-/- mice given d-amphetamine suggests that beneficial effects of this psychostimulant in other rodent models, and ADHD patients, need functional NK1R. Finally, our results reveal experimental variables (stimulus parameters, stress and time of day) that could influence translational studies
- …
