1,330 research outputs found

    Secondary English Language Arts teachers\u27 perceptions and implementation of change policy

    Full text link
    Research regarding educational reform in the United States has examined change in public schools, including changes in the role of the teacher. Secondary teachers have been studied regarding school leadership, work atmosphere, and resource availability, but research specific to secondary English Language Arts teachers\u27 perceptions of how policy implementation affects them in their day to day practice is lacKing Factors of change and the effects on teachers\u27 attitudes reflect how teachers as participants of change cope with change reform; This qualitative research study sought a descriptive understanding of practicing secondary English Language Arts teachers and their perceptions regarding the scope and goals of curriculum reform policy through a multiple case study design viewed through a critical perspective. The principal methodological instrument for study is focused interviews and observations with teachers who had been teaching 8--10 years within the district to identify what they knew regarding curriculum policy changes within the past five years of curriculum at the state, district and site level, their current ways of practice, and then assessed how they perceive the impact of curriculum change on their practice. This research examined on a holistic level, the issue of change as it was perceived by the teachers. Furthermore, it examines specific policy implementation related to the role of change, its implementations, and the way in which teachers\u27 perceptions influenced the implementation; The case study sought to gain insights into the ways in which teachers themselves viewed their practice and how their perceptions impacted their classroom teaching. The principal methodological instrument for this study was focused interviews utilizing Fisher\u27s (1999) model of policy evaluation. Five questions directed the research: (1) What counts as change to secondary English Language Arts teachers? (2) In what ways do secondary English Language Arts teachers implement change in the metropolitan schools in which they work? (3) What becomes altered or modified in the classroom materials when secondary English Language Arts teachers implement policy as the basis for change? (4) What are the values or goals that underlie teacher\u27s perceptions of the change relationships between the secondary English Language Arts and policy implementation? (5) How is the secondary English Language Arts teacher\u27s perceptions affected by the implementation of policy change

    The prevalence of secondary neoplasms in acromegalic patients:possible preventive and/or protective role of metformin

    Get PDF
    Background Acromegaly is a rare disease due to chronic growth hormone (GH) excess and the consequent increase in insulin-like growth factor-1 (IGF-1) levels. Both GH and IGF-1 play a role in intermediate metabolism affecting glucose homeostasis. The association between hyperinsulinemia/impaired glucose tolerance and an increased risk of cancer has been clarified. Insulin has a mitogenic effect through its interaction with the IGF-1 receptor (IGF-1R) that also binds IGF-1. On the other hand, metformin, an anti-hyperglycemic drug that decreases serum levels of insulin and IGF-1, could have a protective role in the treatment of endocrine tumors. Methods A retrospective, observational, multicenter study in 197 acromegalic patients, receiving/not receiving metformin, was performed to assess whether the prevalence of neoplasms might be correlated with insulin resistance and could eventually be modified by metformin treatment. Results In general, the occurrence of secondary neoplasia among our patients was significantly (pV = 0.035) associated with a positive family history of malignancy and with disease duration; a trend towards significance was observed in patients aged > 50 years. Acromegalic subjects who had undergone surgery showed a lower probability of developing a malignant tumor, whereas a higher prevalence of malignancies was observed in obese patients. No significant statistical difference was found when comparing metformin-treated or -untreated subjects for the presence of a second tumor. More interestingly, a trend towards statistical significance (pV = 0.065) was demonstrated in the metformin-treated group for the onset of a benign neoplasm. Conclusion Metformin could act directly on tumor cell metabolism and may have an adjuvant role in benign lesion progression

    Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV

    Get PDF

    A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality

    Get PDF
    The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (Xmax_{max}) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of Xmax_{max} with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy

    Study on multi-ELVES in the Pierre Auger Observatory

    Get PDF
    Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity

    Outreach activities at the Pierre Auger Observatory

    Get PDF

    The ultra-high-energy cosmic-ray sky above 32 EeV viewed from the Pierre Auger Observatory

    Get PDF

    First results from the AugerPrime Radio Detector

    Get PDF

    Update of the Offline Framework for AugerPrime

    Get PDF

    The depth of the shower maximum of air showers measured with AERA

    Get PDF
    corecore