431 research outputs found
Nominally forbidden transitions in the interband optical spectrum of quantum dots
We calculate the excitonic optical absorption spectra of (In,Ga)As/GaAs
self-assembled quantum dots by adopting an atomistic pseudopotential approach
to the single-particle problem followed by a configuration-interaction approach
to the many-body problem. We find three types of allowed transitions that would
be naively expected to be forbidden. (i) Transitions that are parity forbidden
in simple effective mass models with infinite confining wells (e.g. 1S-2S,
1P-2P) but are possible by finite band-offsets and orbital-mixing effects; (ii)
light-hole--to--conduction transitions, enabled by the confinement of
light-hole states; and (iii) transitions that show and enhanced intensity due
to electron-hole configuration mixing with allowed transitions. We compare
these predictions with results of 8-band k.p calculations as well as recent
spectroscopic data. Transitions in (i) and (ii) explain recently observed
satellites of the allowed P-P transitions.Comment: Version published in Phys. Rev.
Printed circuit board coils of multi-track litz structure for 3.3 kW inductive power transfer system
This paper presents the optimization procedure of an inductive power transmission (IPT) system which utilizes large size spiral printed circuit board (PCB) coils for high- power transfer. Printed circuit boards for coil assembly provides advantages in the manufacturing process through the use of cost- effective flexible fabrication techniques. Furthermore, this kind of construction offers a low profile device, which is of great interest for applications with space constraints. PCB-based IPT system coils can achieve high energy efficiency by applying litz-structure braiding techniques, as investigated in this work, where the objective was to obtain an optimized balance between the conduc- tion losses and proximity losses associated with the number and dimensions of the traces. Considering the geometrical dimensions and manufacturing constraints, we will proceed to obtain the characteristics of the coil to achieve optimal performance. The estimation of coil losses were in part based on finite element simulations, and the results were conveniently processed with the appropriate mathematical methods. Numerical simulation and experimental results were conducted for validation on a prototype suitable to transfer up to 3.3 kW for a transmitter- receiver distance of 10 cm. In the experimental arrangement, a maximum efficiency in the coils of 93% has been measured, and the overall efficiency of 88% has been reached for the entire IPT system
Eco-Epidemiological and Immunological Features of Localized Cutaneous Leishmaniasis in Southeastern Mexico: Thirty Years of Study
The Yucatan Peninsula is considered an important endemic area of localized cutaneous leishmaniasis (LCL) caused by Leishmania (Leishmania) mexicana and mainly the states of Campeche and Quintana Roo where 41.5% of all new cases in Mexico were reported in 2015. People were affected due to the lack of the resources for early diagnosis and treatment and although many aspects of the disease are known, control of LCL is absent in this region. Thus, better case detection and epidemiological surveillance are required. The presence of emerging focus and changes in the clinical form suggest the importance of continuing the eco-epidemiological studies, which could lead to the implementation of a sustainable control on the disease. In this review, we focus on the results of our multi-disciplinary studies carried out in the southeastern Mexico, including LCL burden, clinical aspects, causal agents, vectors, reservoirs and the host immune response to Leishmania (L.) mexicana infection
Temperate facultative cleaner wrasses selectively remove ectoparasites from their client-fish in the Azores
Cleaner fishes are key contributors to the health of fish communities. However, much of the information in the literature refers to tropical systems, while fewer studies have examined the activity of cleaner fish inhabiting temperate ecosystems. Facultative cleaner fish are assumed to clean only during their juvenile phase, and have a broader diet than obligatory cleaner fish. Here, we focused on 2 facultative cleaner fish species, Coris julis and Thalassoma pavo, that live along the temperate coasts of the Azorean island of São Miguel. We found that these species focused their cleaning activities on relatively few species of clients, which supports the general idea that facultative cleaner fishes in temperate waters are less dependent on cleaning interactions than obligatory cleaner fishes in tropical waters. Both cleaner species were found to give more bites per host when inspecting larger clients, likely because the latter typically host more parasites. We found that C. julis consumed a greater diversity of food items, which included gnathiid larvae and fewer caligid copepods, compared to T. pavo where no ectoparasites were found. All cleaner fish that we collected after observations of cleaning had eaten gnathiid isopod larvae but not caligid copepods, even though caligid copepods were the most abundant ectoparasite found on the body of 7 selected fish species (including both client and non-client species), suggesting that both species selectively feed on gnathiid isopods. This study is the first to demonstrate that temperate facultative cleaner fish species actively and selectively inspect and remove ectoparasites from their client-fish species.Fundação para a Ciência e Tecnologia (FCT, grant PTDC/MAR/105276/2008. European Regional Development Fund (ERDF) COMPETE - Operational Competitiveness Programme. FCT - Foundation for Science and Techno - project PEst-C/MAR/LA0015/2011.info:eu-repo/semantics/publishedVersio
An approach to predicting patient experience through machine learning and social network analysis.
OBJECTIVE:Improving the patient experience has become an essential component of any healthcare system\u27s performance metrics portfolio. In this study, we developed a machine learning model to predict a patient\u27s response to the Hospital Consumer Assessment of Healthcare Providers and Systems survey\u27s Doctor Communications domain questions while simultaneously identifying most impactful providers in a network. MATERIALS AND METHODS:This is an observational study of patients admitted to a single tertiary care hospital between 2016 and 2020. Using machine learning algorithms, electronic health record data were used to predict patient responses to Hospital Consumer Assessment of Healthcare Providers and Systems survey questions in the doctor domain, and patients who are at risk for responding negatively were identified. Model performance was assessed by area under receiver-operating characteristic curve. Social network analysis metrics were also used to identify providers most impactful to patient experience. RESULTS:Using a random forest algorithm, patients\u27 responses to the following 3 questions were predicted: During this hospital stay how often did doctors. 1) treat you with courtesy and respect? 2) explain things in a way that you could understand? 3) listen carefully to you? with areas under the receiver-operating characteristic curve of 0.876, 0.819, and 0.819, respectively. Social network analysis found that doctors with higher centrality appear to have an outsized influence on patient experience, as measured by rank in the random forest model in the doctor domain. CONCLUSIONS:A machine learning algorithm identified patients at risk of a negative experience. Furthermore, a doctor social network framework provides metrics for identifying those providers that are most influential on the patient experience
The death and the resurrection of (psy)critique: the case of neuroeducation
A rapidly emerging hegemonic neuro-culture and a booming neural subjectivity signal the entry point for an inquiry into the status of the signifier neuro as a universal passe-partout. The wager of this paper is that the various (mis)appropriations of the neurosciences in the media and in academia itself point to something essential, if not structural, in connection with both the discipline of the neurosciences and the current socio-cultural and ideological climate. Starting from the case of neuroeducation (the application of neuroscience within education), the genealogy of the neurological turn is linked to the history of psychology and its inextricable bond with processes of psychologisation. If the neurological turn risks not merely neglecting the dimension of critique, but also obviating its possibility, then revivifying a psy-critique (understanding the academified modern subject as grounded in the scientific point of view from nowhere) might be necessary in order to understand today’s neural subjectivity and its place within current biopolitics
Synovial hemangioma of the knee joint in a 12-year-old boy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Synovial hemangioma is a rare condition and is frequently misdiagnosed, leading to a diagnostic delay of many years.</p> <p>Case presentation</p> <p>We present a case of an atypical synovial hemangioma in a 12-year-old Caucasian boy with a diagnostic delay of 3 years.</p> <p>Conclusion</p> <p>It is important to know that synovial hemangioma mostly affects the knee joint, showing recurrent bloody effusions without a history of trauma. If there are no intermittent effusions, the diagnosis will be even more difficult. In cases of nonspecific symptoms and longstanding knee pain the diagnosis of a synovial hemangioma should also be considered in order to avoid diagnostic delay. Magnetic resonance imaging is the main diagnostic tool to evaluate patients with synovial hemangioma, showing characteristic lace-like or linear patterns.</p> <p>Angiography can identify feeder vessels and offers the possibility of embolisation in the same setting. Surgical excision, either done per arthroscopy or per arthrotomy, is recommended as soon as possible to avoid the risk of damage to the cartilage.</p
Mapping of neurokinin b in the cat brainstem
Abstract We studied the distribution of neurokinin B-immunoreactive cell bodies and fibers in the cat brainstem using an indirect immunoperoxidase technique. The highest density of immunoreactive fibers was found in the motor trigeminal nucleus, the laminar and alaminar spinal trigeminal nuclei, the facial nucleus, the marginal nucleus of the brachium conjunctivum, the locus coeruleus, the cuneiform nucleus, the dorsal motor nucleus of the vagus, the postpyramidal nucleus of the raphe, the lateral tegmental field, the Ko¨lliker-Fuse nucleus, the inferior central nucleus, the periaqueductal gray, the nucleus of the solitary tract, and in the inferior vestibular nucleus. Immunoreactive cell bodies containing neurokinin B were observed, for example, in the locus coeruleus, the dorsal motor nucleus of the vagus, the median division of the dorsal nucleus of the raphe, the lateral tegmental field, the pericentral nucleus of the inferior colliculus, the internal division of the lateral reticular nucleus, the inferior central nucleus, the periaqueductal gray, the postpyramidal nucleus of the raphe, and in the medial nucleus of the solitary tract. This widespread distribution of neurokinin B in the cat brainstem suggests that the neuropeptide could be involved in many different physiological functions. In comparison with previous studies carried out in the rat brainstem on the distribution of neurokinin B, our results point to a more widespread distribution of this neuropeptide in the cat brainstem. Keywords Neurokinin B AE Brainstem AE Cat AE Immunocytochemistry AE Mapping AE Tachykini
'Education, education, education' : legal, moral and clinical
This article brings together Professor Donald Nicolson's intellectual interest in professional legal ethics and his long-standing involvement with law clinics both as an advisor at the University of Cape Town and Director of the University of Bristol Law Clinic and the University of Strathclyde Law Clinic. In this article he looks at how legal education may help start this process of character development, arguing that the best means is through student involvement in voluntary law clinics. And here he builds upon his recent article which argues for voluntary, community service oriented law clinics over those which emphasise the education of students
Age-Related Changes in the Epithelial and Stromal Compartments of the Mammary Gland in Normocalcemic Mice Lacking the Vitamin D3 Receptor
The vitamin D3 receptor (VDR) serves as a negative growth regulator during mammary gland development via suppression of branching morphogenesis during puberty and modulation of differentiation and apoptosis during pregnancy, lactation and involution. To assess the role of the VDR in the aging mammary gland, we utilized 12, 14, and 16 month old VDR knockout (KO) and wild type (WT) mice for assessment of integrity of the epithelial and stromal compartments, steroid hormone levels and signaling pathways. Our data indicate that VDR ablation is associated with ductal ectasia of the primary mammary ducts, loss of secondary and tertiary ductal branches and atrophy of the mammary fat pad. In association with loss of the white adipose tissue compartment, smooth muscle actin staining is increased in glands from VDR KO mice, suggesting a change in the stromal microenviroment. Activation of caspase-3 and increased Bax expression in mammary tissue of VDR KO mice suggests that enhanced apoptosis may contribute to loss of ductal branching. These morphological changes in the glands of VDR KO mice are associated with ovarian failure and reduced serum 17β-estradiol. VDR KO mice also exhibit progressive loss of adipose tissue stores, hypoleptinemia and increased metabolic rate with age. These developmental studies indicate that, under normocalcemic conditions, loss of VDR signaling is associated with age-related estrogen deficiency, disruption of epithelial ductal branching, abnormal energy expenditure and atrophy of the mammary adipose compartment
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