330 research outputs found

    School-Based Relationships Among Children with or at Risk for Emotional and Behavioral Disorders

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    We investigated the influence of a teacher’s perceived emotional state (e.g., feeling emotionally exhausted; feeling accomplished) on the association between parent-teacher relationships and teacher-child conflict among young children. We used pretest data from a pilot study examining the efficacy of a socio-emotional learning intervention for children with or at risk for emotional or behavioral disorders (EBD). Twenty-six teachers and 45 children (Mean age= 7.46 years; SD = 1.21) participated in the intervention. Teachers rated their relationships with children and their parents using the Parent-Teacher Relationship Scale and Student-Teacher Relationship Scale. Multilevel models showed that teachers with a higher sense of personal accomplishment evidenced a negative association between parent-teacher relationships and teacher-child conflict. However, for teachers who felt emotionally exhausted or those who had a lower sense of personal achievement, the association between parent-teacher relationships and teacher-child conflict either remained unchanged or was positive. We conclude by discussing findings in relation to the importance of increasing teacher efficacy, reducing teacher burnout, and strengthening parent-teacher relationships in schools to improve teacher-child relationships and children’s psychosocial outcomes

    New tunnel diode for zero-bias direct detection for millimeter-wave imagers

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    High-resolution passive millimeter wave imaging cameras require per pixel detector circuitry that is simple, has high sensitivity, low noise, and low power. Detector diodes that do not require bias or local oscillator input, and have high cutoff frequencies are strongly preferred. In addition, they must be manufacturable in large quantities with reasonable uniformity and reproducibility. Such diodes have not been obtainable for W-band and above. We are developing zero-bias square-law detector diodes based on InAs/Alsb/GaAlSb heterostructures which for the first time offer a cost-effective solution for large array formats. The diodes have a high frequency response and are relatively insensitive to growth and process variables. The large zero- bias non-linearity in current floor necessary for detection arises from interband tunneling between the InAs and the GaAlSb layers. Video resistance can be controlled by varying an Alsb tunnel barrier layer thickness. Our analysis shows that capacitance can be further decreased and sensitivity increased by shrinking the diode area, as the diode can have very high current density. DC and RF characterization of these devices and an estimate of their ultimate frequency performance in comparison with commercially available diodes are presented

    A Drosophila screen identifies NKCC1 as a modifier of NGLY1 deficiency

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    N-Glycanase 1 (NGLY1) is a cytoplasmic deglycosylating enzyme. Loss-of-function mutations in the NGLY1 gene cause NGLY1 deficiency, which is characterized by developmental delay, seizures, and a lack of sweat and tears. To model the phenotypic variability observed among patients, we crossed a Drosophila model of NGLY1 deficiency onto a panel of genetically diverse strains. The resulting progeny showed a phenotypic spectrum from 0 to 100% lethality. Association analysis on the lethality phenotype, as well as an evolutionary rate covariation analysis, generated lists of modifying genes, providing insight into NGLY1 function and disease. The top association hit was Ncc69 (human NKCC1/2), a conserved ion transporter. Analyses in NGLY1-/- mouse cells demonstrated that NKCC1 has an altered average molecular weight and reduced function. The misregulation of this ion transporter may explain the observed defects in secretory epithelium function in NGLY1 deficiency patients

    Design, fabrication, and performance of infrared and visible vertical cavity surface emitting lasers”,

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    Abstract-This paper discusses the issues involving the design and fabrication of vertical-cavity surface-emitting lasers (VCSEL's). A review of the basic experimental structures is given, with emphasis on recent developments in distributed Bragg reflectors, gain media, as well as current and optical confinement techniques. The paper describes present VCSEL performance, in particular, those involving selective oxidation and visible wavelength operation

    New tunnel diode for zero-bias direct detection for millimeter-wave imagers

    Get PDF
    High-resolution passive millimeter wave imaging cameras require per pixel detector circuitry that is simple, has high sensitivity, low noise, and low power. Detector diodes that do not require bias or local oscillator input, and have high cutoff frequencies are strongly preferred. In addition, they must be manufacturable in large quantities with reasonable uniformity and reproducibility. Such diodes have not been obtainable for W-band and above. We are developing zero-bias square-law detector diodes based on InAs/Alsb/GaAlSb heterostructures which for the first time offer a cost-effective solution for large array formats. The diodes have a high frequency response and are relatively insensitive to growth and process variables. The large zero- bias non-linearity in current floor necessary for detection arises from interband tunneling between the InAs and the GaAlSb layers. Video resistance can be controlled by varying an Alsb tunnel barrier layer thickness. Our analysis shows that capacitance can be further decreased and sensitivity increased by shrinking the diode area, as the diode can have very high current density. DC and RF characterization of these devices and an estimate of their ultimate frequency performance in comparison with commercially available diodes are presented

    Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis

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    Background More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+)to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.Methods In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.Findings We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+.After 5\u20138 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0\ub717, 95% CI 0\ub711\u20130\ub725) among girls aged 13\u201319 years, and decreased significantly by 66% (RR 0\ub734, 95% CI 0\ub723\u20130\ub749) among women aged 20\u201324 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0\ub746, 95% CI 0\ub733\u20130\ub766) among girls aged 13\u201319 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0\ub733, 95% CI 0\ub724\u20130\ub746) among girls aged 15\u201319 years, decreased significantly by 54% (RR 0\ub746, 95% CI 0.36\u20130.60) among women aged 20\u201324 years, and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub753\u20130\ub789) among women aged 25\u201329 years. Among boys aged 15\u201319 years anogenital wart diagnoses decreased significantly by 48% (RR 0\ub752, 95% CI 0\ub737\u20130\ub775) and among men aged 20\u201324 years they decreased significantly by 32% (RR 0\ub768, 95% CI 0\ub747\u20130\ub798). After 5\u20139 years of vaccination, CIN2+ decreased significantly by 51% (RR 0\ub749, 95% CI 0\ub742\u20130\ub758) among screened girls aged 15\u201319 years and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub757\u20130\ub784) among women aged 20\u201324 years.Interpretation This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects

    Population-level effects of human papillomavirus vaccination programs on infections with nonvaccine genotypes

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    We analyzed human papillomavirus (HPV) prevalences during prevaccination and postvaccination periods to consider possible changes in nonvaccine HPV genotypes after introduction of vaccines that confer protection against 2 high-risk types, HPV16 and HPV18. Our meta-analysis included 9 studies with data for 13,886 girls and women ≀19 years of age and 23,340 women 20–24 years of age. We found evidence of cross-protection for HPV31 among the younger age group after vaccine introduction but little evidence for reductions of HPV33 and HPV45. For the group this same age group, we also found slight increases in 2 nonvaccine high-risk HPV types (HPV39 and HPV52) and in 2 possible high-risk types (HPV53 and HPV73). However, results between age groups and vaccines used were inconsistent, and the increases had possible alternative explanations; consequently, these data provided no clear evidence for type replacement. Continued monitoring of these HPV genotypes is important

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie
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