1,150 research outputs found
Fabrication and Comprehensive Modeling of Ion-Exchanged Bragg Opitcal Add-Drop Multiplexers
Optical add–drop multiplexers (OADMs) based on asymmetric Y branches and tilted gratings offer excellent-performance in wavelength-division multiplexed systems. To simplify waveguide fabrication, ion-exchange techniques appear to be an important option in photosensitive glasses. Optimum OADM performance depends on how accurately the waveguide fabrication process and tilted Bragg grating operation are understood and modeled. Results from fabrication and comprehensive modeling are compared for ion-exchange processes that use different angles of the tilted grating. The transmission and reflection spectra for the fabricated and simulated OADMs show excellent agreement. The OADM’s performance is evaluated in terms of the measured characteristics of the Y branches and tilted gratings
Buried Ion-Exchanged Glass Wavelengths: Burial-Depth Dependence on Waveguide Width
A detailed theoretical and experimental study of the depth dependence of buried ion-exchanged waveguides on waveguide width is reported. Modeling, which includes the effect of nonhomogeneous time-dependent electric field distribution, agrees well with our experiments showing that burial depth increases linearly with waveguide width. These results may be used in the proper design of integrated optical circuits that need waveguides of different widths at different sections, such as arrayed waveguide gratings
Comparing Alternative Breast Milk Feeding Questions to U.S. Breastfeeding Surveillance Questions
Background: Most mothers in the United States express their milk, which is then bottle fed to their infants. The National Immunization Survey (NIS), used to report national breastfeeding prevalence, asks about infant breast milk consumption, regardless of whether it is consumed at the mother\u27s breast or from a bottle. The NIS data are often erroneously interpreted, however, to mean prevalence of at-the-breast feeding. We hypothesized that over half of infants classified as breastfed at 3, 6, and 12 months by the NIS questions would also be consuming expressed breast milk.
Materials and Methods: A convenience sample of 456 mothers of infants 19?35 months of age recruited through ResearchMatch.org completed an online infant-feeding questionnaire. The questionnaire included both the NIS questions and more-detailed questions about feeding mode, distinguishing between at-the-breast and bottle.
Results: Based on responses of our sample to the NIS questions, it could be interpreted that 74%, 64%, and 39% of mother?infant dyads were at-the-breast feeding at 3, 6, and 12 months, respectively. However, at each time point, most infants consumed at least some breast milk from a bottle. As infants got older, the proportion of breast milk consumed from a bottle increased.
Conclusions: In this U.S. sample, the predominant breast milk feeding style involves both at-the-breast and expressed breast milk feeding. Future research and national surveillance should consider including separate measures of maternal breast milk expression and infant consumption of expressed breast milk to enable meaningful exploration of maternal and infant outcomes associated with these asynchronous behaviors
'Another, More Sinister Reality': Class, Youth and Psychopathology from Saturday Night and Sunday Morning to Endless Night
This article analyses how the protagonists of films such as Saturday Night and Sunday Morning (1959), The Collector (1965), Blow Up (1966), Twisted Nerve (1968) and Endless Night (1972) were understood in relation to debates over the supposed perils of the new affluence and the erosion of class distinctions that it was presumed to entail. In particular it examines the terms in which these issues were discussed within contemporaneous reviews of the films, terms that were insistently psychological. These protagonists, as well as, to a certain extent, the actors who played them, were seen as representing a nightmare image of a ‘new’ working class that no longer ‘knew its place’, and as manifesting psychological problems that were associated with this intermediate status. Their psychologies were interpreted by many critics as being distinguished by a sense of isolation from external reality and by a hostile relationship to the world characterised by a psychopathic lack of empathy. Such concerns could be seen as establishing certain parallels between working-class realism and the contemporaneous horror film, and indeed the reviews cited in this article demonstrate that working-class realism and horror were seen as having shared points of interest in the 1960s, points that have often been repressed by the tendency to compartmentalise British cinema history into separate or even opposed ‘traditions’
Guidelines for the use of cell lines in biomedical research
Cell-line misidentification and contamination with microorganisms, such as mycoplasma, together with instability, both genetic and phenotypic, are among the problems that continue to affect cell culture. Many of these problems are avoidable with the necessary foresight, and these Guidelines have been prepared to provide those new to the field and others engaged in teaching and instruction with the information necessary to increase their awareness of the problems and to enable them to deal with them effectively. The Guidelines cover areas such as development, acquisition, authentication, cryopreservation, transfer of cell lines between laboratories, microbial contamination, characterisation, instability and misidentification. Advice is also given on complying with current legal and ethical requirements when deriving cell lines from human and animal tissues, the selection and maintenance of equipment and how to deal with problems that may arise
Midterm outcomes of the Zenith Renu AAA Ancillary Graft
ObjectiveThe Zenith Renu abdominal aortic aneurysm (AAA) Ancillary Graft (Cook Medical Inc, Bloomington, Ind) provides active proximal fixation for treatment of pre-existing endografts with failed or failing proximal fixation or seal. The purpose of this study was to evaluate the midterm outcomes of treatment with this device.MethodsFrom September 2005 to November 2006, a prospective, nonrandomized, multicenter, postmarket registry was utilized to collect physician experiences from 151 cases (89 converters and 62 main body extensions) at 95 institutions. Preoperative indications and procedural and postimplantation outcomes were collected and analyzed. Technical success and clinical success were determined as defined by the Society of Vascular Surgery reporting standards.ResultsPatients were predominantly male (87%) with a mean age of 77 years. The interval between the original endograft implantation to Renu treatment was 43.4 ± 18.7 months. The indications for treatment were endoleak (n = 111), migration (n = 136), or both (n = 94). Technical success was 98.0% with two cases of intraoperative conversion and one case of persistent type IA endoleak. The median follow-up for the cohort was 45.0 months (range, 0-56 months; interquartile range, 25.0 months). Overall, 32 cases had treatment failures that included at least one of the following: death (n = 5), type I/III endoleak (n = 18), graft infection (n = 1), thrombosis (n = 1), aneurysm enlargement >5 mm (n = 9), rupture (n = 4), conversion (n = 9, with 7 after 30 days), and migration (n = 1). Overall, the clinical success for the entire cohort during the follow-up period was 78.8% (119/151).ConclusionsThe postmarket registry data confirm that the Zenith Renu AAA Ancillary Graft can be used to treat endovascular repairs that failed due to proximal attachment failures. The salvage treatment with the Renu device had high technical success rate and resulted in clinical success in a majority of patients (78.8%). While failed endovascular repairs can be salvaged, a clinical failure in one of five patients still emphasizes the importance of patient and device selection during initial endovascular aneurysm repair to ensure durable success
Amyotrophic Lateral Sclerosis: Proteins, Proteostasis, Prions, and Promises
Copyright 2020 McAlary, Chew, Lum, Geraghty, Yerbury and Cashman. Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of the motor neurons that innervate muscle, resulting in gradual paralysis and culminating in the inability to breathe or swallow. This neuronal degeneration occurs in a spatiotemporal manner from a point of onset in the central nervous system (CNS), suggesting that there is a molecule that spreads from cell-to-cell. There is strong evidence that the onset and progression of ALS pathology is a consequence of protein misfolding and aggregation. In line with this, a hallmark pathology of ALS is protein deposition and inclusion formation within motor neurons and surrounding glia of the proteins TAR DNA-binding protein 43, superoxide dismutase-1, or fused in sarcoma. Collectively, the observed protein aggregation, in conjunction with the spatiotemporal spread of symptoms, strongly suggests a prion-like propagation of protein aggregation occurs in ALS. In this review, we discuss the role of protein aggregation in ALS concerning protein homeostasis (proteostasis) mechanisms and prion-like propagation. Furthermore, we examine the experimental models used to investigate these processes, including in vitro assays, cultured cells, invertebrate models, and murine models. Finally, we evaluate the therapeutics that may best prevent the onset or spread of pathology in ALS and discuss what lies on the horizon for treating this currently incurable disease
Value of traditional oral narratives in building climate-change resilience: insights from rural communities in Fiji
In the interests of improving engagement with Pacific Island communities to enable development of effective and
sustainable adaptation strategies to climate change, we looked at how traditional oral narratives in rural/peripheral Fiji communities might be used to inform such strategies. Interviews were undertaken and observations made in 27 communities; because the custodians of traditional knowledge were targeted, most interviewees were 70-79 years old.
The view that oral traditions, particularly those referring to environmental history and the observations/precursors of environmental
change, were endangered was widespread and regretted. Interviewees’ personal experiences of extreme events (natural disasters) were commonplace but no narratives of historical (unwitnessed by interviewees) events were found. In contrast, experiences of previous village relocations attributable (mainly) to environmental change were recorded in five communities while awareness of environmentally driven migration was more common. Questions about climate change elicited views dominated by religious/fatalist beliefs but included some more pragmatic ones; the confusion of climate change with climate variability, which is part of traditional knowledge, was widespread.
The erosion of traditional environmental knowledge in the survey communities over recent decades has been severe and is likely to continue apace, which will reduce community self-sufficiency and resilience. Ways of conserving such knowledge and incorporating it
into adaptation planning for Pacific Island communities in rural/peripheral locations should be explored
New generalized fuzzy metrics and fixed point theorem in fuzzy metric space
In this paper, in fuzzy metric spaces (in the sense of Kramosil and Michalek (Kibernetika 11:336-344, 1957)) we introduce the concept of a generalized fuzzy metric which is the extension of a fuzzy metric. First, inspired by the ideas of Grabiec (Fuzzy Sets Syst. 125:385-389, 1989), we define a new G-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by M Grabiec). Next, inspired by the ideas of Gregori and Sapena (Fuzzy Sets Syst. 125:245-252, 2002), we define a new GV-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by V Gregori and A Sapena). Moreover, we provide the condition guaranteeing the existence of a fixed point for these single-valued contractions. Next, we show that the generalized pseudodistance J:X×X→[0,∞) (introduced by Włodarczyk and Plebaniak (Appl. Math. Lett. 24:325-328, 2011)) may generate some generalized fuzzy metric NJ on X. The paper includes also the comparison of our results with those existing in the literature
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