2,334 research outputs found
Perbandingan Hasil Belajar Siswa Menggunakan Media Audio Visual Dengan Media Kolase Pada Mata Pelajaran IPS Terpadu Kelas VIII SMP 18 Banda Aceh
Media belajar merupakan suatu alat bantu yang dapat ditangkap oleh pancaindera yang berisi pesan yang ingin disampaikan kepada siswa yang dapat digunakan oleh setiap orang dan berhubungan dengan materi ajar dengan fungsi sebagai alat bantu dalam proses pembelajaran yang membantu menjelaskan materi, adapun media pembelajaran yang dapat digunakan adalah audio visual dan kolase. Media audio visual dan Kolase memiliki kesamaan dalam penyajian materi sedangkan perbedaannya adalah media audio visual dapat menampilkan sesuatu yang detail dari benda yang bergerak sedangkan kolase menekankan pada indera penglihatan dan tetap tidak memperlihatkan gerak seperti halnya gambar hidup. Rumusan masalah dalam penelitian ini adalah apakah hasil belajar siswa menggunakan media audio visual lebih baik dari pada media kolase pada mata pelajaran IPS Terpadu kelas VIII SMP Negeri 18 Banda Aceh. Penelitian ini bertujuan untuk mengetahui apakah hasil belajar siswa menggunakan media audio visual lebih baik dari pada media kolase pada mata pelajaran IPS Terpadu kelas VIII SMP Negeri 18 Banda Aceh. Populasi dalam penelitian ini ialah seluruh siswa kelas VIII yang berjumlah 152 siswa. Pengambilan sampel dalam penelitian ini hanya dua kelas yakni kelas VIII-3 sebanyak 30 siswa dan kelas VIII-4 sebanyak 30 siswa. Teknik pengumpulan data berupa pemberian tes kepada siswa, yakni pre-test dan post-test. Teknik pengolahan data dilakukan dengan uji-t. Hasil pengolahan data penelitian diperoleh thitung = 2,31 yang lebih besar dari ttabel = 1,67 pada taraf signifikansi 0,05 dan dk = 58, maka H0 ditolak dan Ha diterima. Simpulan yang dapat diambil adalah hasil belajar IPS Terpadu yang menggunakan media pembelajaran Audio Visual lebih baik dibandingkan dengan hasil belajar yang menggunakan media pembelajaran kolase pada siswa SMP Negeri 18 Banda Aceh
Formalizing a hierarchical file system
An abstract file system is defined here as a partial function from (absolute) paths to data. Such a file system determines the set of valid paths. It allows the file system to be read and written at a valid path, and it allows the system to be modified by the Unix operations for creation, removal, and moving of files and directories. We present abstract definitions (axioms) for these operations. This specification is refined towards a pointer implementation. The challenge is to have a natural abstraction function from the implementation to the specification, to define operations on the concrete store that behave exactly in the same way as the corresponding functions on the abstract store, and to prove these facts. To mitigate the problems attached to partial functions, we do this in two steps: first a refinement towards a pointer implementation with total functions, followed by one that allows partial functions. These two refinements are proved correct by means of a number of invariants. Indeed, the insights gained consist, on the one hand, of the invariants of the pointer implementation that are needed for the refinement functions, and on the other hand of the precise enabling conditions of the operations on the different levels of abstraction. Each of the three specification levels is enriched with a permission system for reading, writing, or executing, and the refinement relations between these permission systems are explored. Files and directories are distinguished from the outset, but this rarely affects our part of the specifications. All results have been verified with the proof assistant PVS, in particular, that the invariants are preserved by the operations, and that, where the invariants hold, the operations commute with the refinement functions
Mobile Computing in Physics Analysis - An Indicator for eScience
This paper presents the design and implementation of a Grid-enabled physics
analysis environment for handheld and other resource-limited computing devices
as one example of the use of mobile devices in eScience. Handheld devices offer
great potential because they provide ubiquitous access to data and
round-the-clock connectivity over wireless links. Our solution aims to provide
users of handheld devices the capability to launch heavy computational tasks on
computational and data Grids, monitor the jobs status during execution, and
retrieve results after job completion. Users carry their jobs on their handheld
devices in the form of executables (and associated libraries). Users can
transparently view the status of their jobs and get back their outputs without
having to know where they are being executed. In this way, our system is able
to act as a high-throughput computing environment where devices ranging from
powerful desktop machines to small handhelds can employ the power of the Grid.
The results shown in this paper are readily applicable to the wider eScience
community.Comment: 8 pages, 7 figures. Presented at the 3rd Int Conf on Mobile Computing
& Ubiquitous Networking (ICMU06. London October 200
Fine Needle Aspiration Cytology (FNAC) in the Management of Thyroid Pathology - The Aga Khan University Hospital Experience
Objective: To report the efficacy of FNAC in patients with thyroid disease.Methods: Between January 1990 and December 1994 the records of all patients treated surgically for thyroid disease at ENT Head and Neck Surgery of Aga Khan University were reviewed. All the patients had preÂoperative FNAC as the first line of evaluation and the histopathologist examined post-operative thyroid specimen.Results: Forty-five patients (36 female and 9 male) had thyroid surgery. In 26 patients out of 45, FNAC was conclusive in diagnosing the nature of disease, while in 19 patients the FNAC was inconclusive because of the presence of follicular cell neoplasia.Conclusion: Our results indicate that the FNAC is very accurate and a reliable test in the diagnosis of thyroid pathology, however, to distinguish follicular adenoma from follicular carcinoma final histology is required. FNAC is cost effective method of evaluating thyroid pathology pre-operatively and plays a vital role in planning the surgical management of thyroid nodule OPMA 49:133, 1999)
Antidepressant use in relation to dementia risk, cognitive decline, and brain atrophy
INTRODUCTION: We aimed to assess the effect of antidepressant use on dementia risk, cognitive decline, and brain atrophy. METHODS: In this prospective cohort study, we included 5511 dementia-free participants (Mini-Mental State Examination [MMSE] > 25) of the Rotterdam study (57.5% women, mean age 70.6 years). Antidepressant use was extracted from pharmacy records from 1991 until baseline (2002–2008). Incident dementia was monitored from baseline until 2018, with repeated cognitive assessment and magnetic resonance imaging (MRI) every 4 years. RESULTS: Compared to never use, any antidepressant use was not associated with dementia risk (hazard ratio [HR] 1.14, 95% confidence interval [CI] 0.92–1.41), or with accelerated cognitive decline or atrophy of white and gray matter. Compared to never use, dementia risk was somewhat higher with tricyclic antidepressants (HR 1.36, 95% CI 1.01–1.83) than with selective serotonin reuptake inhibitors (HR 1.12, 95% CI 0.81–1.54), but without dose–response relationships, accelerated cognitive decline, or atrophy in either group. DISCUSSION: Antidepressant medication in adults without indication of cognitive impairment was not consistently associated with long-term adverse cognitive effects. Highlights: Antidepressant medications are frequently prescribed, especially among older adults. In this study, antidepressant use was not associated with long-term dementia risk. Antidepressant use was not associated with cognitive decline or brain atrophy. Our results support safe prescription in an older, cognitively healthy population.</p
Antidepressant use in relation to dementia risk, cognitive decline, and brain atrophy
INTRODUCTION: We aimed to assess the effect of antidepressant use on dementia risk, cognitive decline, and brain atrophy. METHODS: In this prospective cohort study, we included 5511 dementia-free participants (Mini-Mental State Examination [MMSE] > 25) of the Rotterdam study (57.5% women, mean age 70.6 years). Antidepressant use was extracted from pharmacy records from 1991 until baseline (2002–2008). Incident dementia was monitored from baseline until 2018, with repeated cognitive assessment and magnetic resonance imaging (MRI) every 4 years. RESULTS: Compared to never use, any antidepressant use was not associated with dementia risk (hazard ratio [HR] 1.14, 95% confidence interval [CI] 0.92–1.41), or with accelerated cognitive decline or atrophy of white and gray matter. Compared to never use, dementia risk was somewhat higher with tricyclic antidepressants (HR 1.36, 95% CI 1.01–1.83) than with selective serotonin reuptake inhibitors (HR 1.12, 95% CI 0.81–1.54), but without dose–response relationships, accelerated cognitive decline, or atrophy in either group. DISCUSSION: Antidepressant medication in adults without indication of cognitive impairment was not consistently associated with long-term adverse cognitive effects. Highlights: Antidepressant medications are frequently prescribed, especially among older adults. In this study, antidepressant use was not associated with long-term dementia risk. Antidepressant use was not associated with cognitive decline or brain atrophy. Our results support safe prescription in an older, cognitively healthy population.</p
Benzodiazepine use in relation to long-term dementia risk and imaging markers of neurodegeneration:a population-based study
Background: Benzodiazepine use is common, particularly in older adults. Benzodiazepines have well-established acute adverse effects on cognition, but long-term effects on neurodegeneration and dementia risk remain uncertain. Methods: We included 5443 cognitively healthy (MMSE ≥ 26) participants from the population-based Rotterdam Study (57.4% women, mean age 70.6 years). Benzodiazepine use from 1991 until baseline (2005–2008) was derived from pharmacy dispensing records, from which we determined drug type and cumulative dose. Benzodiazepine use was defined as prescription of anxiolytics (ATC-code: N05BA) or sedative-hypnotics (ATC-code: N05CD) between inception of pharmacy records and study baseline. Cumulative dose was calculated as the sum of the defined daily doses for all prescriptions. We determined the association with dementia risk until 2020 using Cox regression. Among 4836 participants with repeated brain MRI, we further determined the association of benzodiazepine use with changes in neuroimaging markers using linear mixed models. Results: Of all 5443 participants, 2697 (49.5%) had used benzodiazepines at any time in the 15 years preceding baseline, of whom 1263 (46.8%) used anxiolytics, 530 (19.7%) sedative-hypnotics, and 904 (33.5%) used both; 345 (12.8%) participants were still using at baseline assessment. During a mean follow-up of 11.2 years, 726 participants (13.3%) developed dementia. Overall, use of benzodiazepines was not associated with dementia risk compared to never use (HR [95% CI]: 1.06 [0.90–1.25]), irrespective of cumulative dose. Risk estimates were somewhat higher for any use of anxiolytics than for sedative-hypnotics (HR 1.17 [0.96–1.41] vs 0.92 [0.70–1.21]), with strongest associations for high cumulative dose of anxiolytics (HR [95% CI] 1.33 [1.04–1.71]). In imaging analyses, current use of benzodiazepine was associated cross-sectionally with lower brain volumes of the hippocampus, amygdala, and thalamus and longitudinally with accelerated volume loss of the hippocampus and to a lesser extent amygdala. However, imaging findings did not differ by type of benzodiazepines or cumulative dose. Conclusions: In this population-based sample of cognitively healthy adults, overall use of benzodiazepines was not associated with increased dementia risk, but potential class-dependent adverse effects and associations with subclinical markers of neurodegeneration may warrant further investigation.</p
Sub-Riemannian Fast Marching in SE(2)
We propose a Fast Marching based implementation for computing sub-Riemanninan
(SR) geodesics in the roto-translation group SE(2), with a metric depending on
a cost induced by the image data. The key ingredient is a Riemannian
approximation of the SR-metric. Then, a state of the art Fast Marching solver
that is able to deal with extreme anisotropies is used to compute a SR-distance
map as the solution of a corresponding eikonal equation. Subsequent
backtracking on the distance map gives the geodesics. To validate the method,
we consider the uniform cost case in which exact formulas for SR-geodesics are
known and we show remarkable accuracy of the numerically computed SR-spheres.
We also show a dramatic decrease in computational time with respect to a
previous PDE-based iterative approach. Regarding image analysis applications,
we show the potential of considering these data adaptive geodesics for a fully
automated retinal vessel tree segmentation.Comment: CIARP 201
COPD is associated with an increased risk of peripheral artery disease and mortality
Patients with chronic obstructive pulmonary disease (COPD) commonly present with multimorbidity. We aimed to investigate the association between COPD and the development of peripheral arterial disease (PAD) in the general population, and how this might affect mortality among individuals with COPD. We included 3123 participants of the population-based Rotterdam Study without PAD at baseline (mean age 65 years; 57.4% female). The association between COPD at baseline and PAD during follow-up was studied using logistic regression (PAD being indicated by an ankle–brachial index (ABI) of 0.9 or less). Cox regression was used for mortality analysis and interaction terms were used to investigate mortality risk modification by PAD. The presence of COPD was associated with incident PAD (adjusted odds ratio 1.9, 95% CI 1.1–3.2). Mortality rates per 100 000 person-years were as follows: 10.0 in individuals without COPD or PAD, 18.4 in those with COPD only, 16.1 in those with PAD only and 30.1 in individuals with both COPD and PAD. No statistical interaction was found between PAD and COPD on risk of dying. Individuals with COPD have an almost doubled risk of developing PAD. Although PAD does not modify the association between COPD and mortality, people suffering from both diseases have substantially higher mortality rates
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