4,710 research outputs found

    Differences in nitrate uptakeamong benthic algal assemblages in a mountain stream

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    We evaluated how benthic algal assemblages that vary in composition, richness, and other diversity metrics remove NO 3 -N from the water column of a mountain stream. Ecological theory and empirical studies suggest that ecosystem process rates should increase as richness increases because of niche separation or activity of dominant taxa. Accordingly, we predicted that algal assemblages with highest richness would show the highest rates of NO 3 -N uptake. To test this prediction, we transplanted 225 rocks representing 3 patch types (green, yellow, and brown) that differed macroscopically in algal composition from a lake outflow stream to a lake inflow stream where an experimental release of 15 N-NO 3 was ongoing. We measured 15 N uptake in each patch type during the stable isotope release. Benthic algal richness varied from 28 genera in the green patch type and 26 genera in the yellow patch type to 22 genera in the brown patch type. Without accounting for differences in chlorophyll a content, NO 3 -N uptake (2.1–3.3 3 10 4 /d) was highest in the green patch type, lowest (0.3–0.6 3 10 4 /d) in the yellow patch type, and intermediate (1.2–1.5 3 10 4 /d) in the brown patch type. NO 3 -N uptake normalized to chlorophyll a increased in concert with algal richness in the 3 patch types. This result supports the hypothesis that increased assemblage diversity leads to higher rates of community processes. Aside from diversity differences per se, lower rates of NO 3 -N uptake in the brown patch type might be the consequence of differences in functional characteristics of the taxa present. Approximately 29% of algal biovolume in the brown patch type consisted of taxa capable of N 2 -fixation, a result that suggests that algae in this patch type might be capable of meeting N needs via N 2 -fixation rather than via removal from the water column

    Benefits and difficulties of the national service training program in Rizal Technological University

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    The primary purpose of this study is to ascertain the benefits of the National Service Training Program (NSTP) implementation and to identify the problems encountered by its implementers. Results showed that the benefits derived from the program were topped by enhancement of skills on basic leadership with emphases on the ability to listen and ability to communicate which were rated very important and very much benefited among other training aspects of the program. Results also revealed that students are aware of the importance of physical, mental and social health as well as the observance of proper hygiene for overall sense of well-being. Although recreation is one aspect that the respondents find important, appreciation of it underscores the need to have more time for assignments and projects as most of the respondents are enrolled in their respective courses with 29 units, making them unable to appreciate the perks of involving themselves into various recreational activities. Problems in the implementation showed lack of provision of materials and equipment and of budgetary allocation which rendered full implementation weak as students and faculty involved in the community immersion have to rely on their own resources, in addition to the indifference and passivity of the local government officials. Based on the findings, the researchers recommended that: the school administrators need to allocate adequate budget for materials and equipment; periodic faculty development trainings and; to look into the passive attitude of the local officials to ensure that implementation NSTP projects will benefit both clients and implementers

    The very fast evolution of Sakurai's object

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    V4334 Sgr (a.k.a. Sakurai's object) is the central star of an old planetary nebula that underwent a very late thermal pulse a few years before its discovery in 1996. We have been monitoring the evolution of the optical emission line spectrum since 2001. The goal is to improve the evolutionary models by constraining them with the temporal evolution of the central star temperature. In addition the high resolution spectral observations obtained by X-shooter and ALMA show the temporal evolution of the different morphological components.Comment: 2 pages, 2 figures to appear in the Proceedings of the IAU Symp. 323: "Planetary nebulae: Multi-wavelength probes of stellar and galactic evolution". Eds. X.-W. Liu, L. Stanghellini and A. Karaka

    Learning Action Cell Implementation in the Philippine Public Schools: A Descriptive Phenomenological Study

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    Philippine DepEd Order (DO) #35, s. 2016, institutionalized the Learning Action Cell (LAC) in public schools. The policy’s key objective is to improve teachers’ teaching competence. Conversely, there needs to be more literature, specifically in the Davao City public schools, to account for its implementation since its inception. Thus, this study. The study aimed to propose a LAC implementation model for the Davao City public school’s division. It made use of qualitative, descriptive phenomenological research design. Ten (10) participants were involved, and they participated in the focus group discussion and key informant interviews. The proposed LAC implementation model focused on the students’ learning as its definitive goal. It can be realized if the teachers’ teaching skills are enhanced, and the LAC implementation is well implemented. Correspondingly, the proposed model emphasizes supportive leadership, teachers’ positive attitudes, well-defined roles and responsibilities, sufficient resources, systematic procedures, and well-disseminated policy. One of the study’s recommendations is for future researchers to study the impact of the continuous improvement model adopted in the implementation of LAC in the DepEd schools on the learning quality of the students and the school improvement. Keywords: teacher professional development, LAC implementation model, academic performance DOI: 10.7176/JEP/14-27-07 Publication date:September 30th 202

    Outdoor and indoor path loss modeling at the sub-THz band

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    In this letter, we present new measurement results to model large-scale path loss at the sub-THz (141-145 GHz) band, for both indoor and outdoor scenarios. Extensive measurement campaigns have been carried out, taking into account both line-of-sight (LoS) and non line-of-sight (NLoS) propagation. For all considered propagation scenarios, existing omni-directional and directional path loss model have been developed, based on the so-called close-in (CI) free-space reference distance model. Moreover, path loss modeling is applied for the 2nd and 3rd strongest multipath components (MPCs). Thus, path loss exponent and large-scale shadow fading estimates are provided. Moreover, power angular spread analysis is depicted, using power angular information up to the 3rd strongest MP

    Selpercatinib in Patients With RET Fusion–Positive Non–Small-Cell Lung Cancer: Updated Safety and Efficacy From the Registrational LIBRETTO-001 Phase I/II Trial

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    Selpercatinib; Lung cancer; SafetySelpercatinib; Cáncer de pulmón; SeguridadSelpercatinib; Càncer de pulmó; SeguretatPURPOSE Selpercatinib, a first-in-class, highly selective, and potent CNS-active RET kinase inhibitor, is currently approved for the treatment of patients with RET fusion–positive non–small-cell lung cancer (NSCLC). We provide a registrational data set update in more than double (n = 316) of the original reported population (n = 144) and better characterization of long-term efficacy and safety. METHODS Patients were enrolled to LIBRETTO-001, a phase I/II, single-arm, open-label study of selpercatinib in patients with RET-altered cancers. An analysis of patients with RET fusion–positive NSCLC, including 69 treatment-naive and 247 with prior platinum-based chemotherapy, was performed. The primary end point was objective response rate (ORR; RECIST v1.1, independent review committee). Secondary end points included duration of response (DoR), progression-free survival (PFS), overall survival, and safety. RESULTS In treatment-naive patients, the ORR was 84% (95% CI, 73 to 92); 6% achieved complete responses (CRs). The median DoR was 20.2 months (95% CI, 13.0 to could not be evaluated); 40% of responses were ongoing at the data cutoff (median follow-up of 20.3 months). The median PFS was 22.0 months; 35% of patients were alive and progression-free at the data cutoff (median follow-up of 21.9 months). In platinum-based chemotherapy pretreated patients, the ORR was 61% (95% CI, 55 to 67); 7% achieved CRs. The median DoR was 28.6 months (95% CI, 20.4 to could not be evaluated); 49% of responses were ongoing (median follow-up of 21.2 months). The median PFS was 24.9 months; 38% of patients were alive and progression-free (median follow-up of 24.7 months). Of 26 patients with measurable baseline CNS metastasis by the independent review committee, the intracranial ORR was 85% (95% CI, 65 to 96); 27% were CRs. In the full safety population (n = 796), the median treatment duration was 36.1 months. The safety profile of selpercatinib was consistent with previous reports. CONCLUSION In a large cohort with extended follow-up, selpercatinib continued to demonstrate durable and robust responses, including intracranial activity, in previously treated and treatment-naive patients with RET fusion–positive NSCLC.Supported by Loxo Oncology, a wholly owned subsidiary of Eli Lilly and Company. A.D. was supported in part by funding from the National Cancer Institute of the National Institutes of Health: 1R01CA251591- 01A1 and P30 CA008748. Partial support was likewise provided by LUNGevity

    Near-Infrared Imaging of Early-Type Galaxies III. The Near-Infrared Fundamental Plane

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    Near-infrared imaging data on 251 early-type galaxies in clusters and groups are used to construct the near-infrared Fundamental Plane (FP) r_eff ~ sigma_0^1.53 _eff^-0.79. The slope of the FP therefore departs from the virial expectation of r_eff ~ sigma_0^2 _eff^-1 at all optical and near-infrared wavelengths, which could be a result of the variation of M/L along the elliptical galaxy sequence, or a systematic breakdown of homology among the family of elliptical galaxies. The slope of the near-infrared FP excludes metallicity variations as the sole cause of the slope of the FP. Age effects, dynamical deviations from a homology, or any combination of these (with or without metallicity), however, are not excluded. The scatter of both the near-infrared and optical FP are nearly identical and substantially larger than the observational uncertainties, demonstrating small but significant intrinsic cosmological scatter for the FP at all wavelengths. The lack of a correlation of the residuals of the near-infrared FP and the residuals from the Mg_2-sigma relation indicates that the thickness of these relations cannot be ascribed only to age or metallicity effects. Due to this metallicity independence, the small scatter of the near-infrared FP excludes a model in which age and metallicity effects ``conspire'' to keep the optical FP thin. All of these results suggest that the possible physical origins of the FP relations are complicated due to combined effects of variations of stellar populations and structural parameters among elliptical galaxies.Comment: to appear in The Astronomical Journal; 35 pages, including 13 Postscript figures and 1 table; uses AAS LaTeX style file

    Near-Infrared Imaging of Early-Type Galaxies IV. The Physical Origins of the Fundamental Plane Scaling Relations

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    The physical origins of the Fundamental Plane (FP) scaling relations are investigated for early-type galaxies observed at optical and near-infrared wavelengths. The slope for the FP is shown to increase systematically with wavelength from the U-band through the K-band. A distance-independent construction of the observables is described which provides an accurate measurement of the change in the FP slope between any pair of bandpasses. The variation of the FP slope with wavelength is strong evidence of systematic variations in stellar content along the elliptical galaxy sequence. The intercept of the diagnostic relationship between log(D_K/D_V) and log(sigma_0) shows no significant dependence on environment within the uncertainties of the Galactic extinction corrections, demonstrating the universality of the stellar populations contributions at the level of Delta(V-K)=0.03 mag to the zero-point of the global scaling relations. Several other constraints on the properties of early-type galaxies --- the slope of the Mg_2-sigma_0 relation, the effects of stellar populations gradients, and deviations of early-type galaxies from a dynamically homologous family --- are included to construct an empirical, self-consistent model which provides a complete picture of the underlying physical properties which are varying along the early-type galaxy sequence. This empirical approach demonstrates that there are significant systematic variations in both age and metallicity along the elliptical galaxy sequence, and that a small, but systematic, breaking of dynamical homology (or a similar, wavelength independent effect) is required. Predictions for the evolution of the slope of the FP with redshift are described. [abriged]Comment: to appear in The Astronomical Journal; 40 pages, including 10 Postscript figures and 3 tables; uses AAS LaTeX style file
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