4,207 research outputs found
PERANCANGAN SARANA PUSAT PENDIDIKAN DAN LATIHAN OLAHRAGA PELAJAR PROVINSI GORONTALO
PPLP Provinsi Gorontalo sejak tahun 2017 hingga 2021 mengalami peningkatan dari tahun ke tahun. Berdasarkan data primer dari Dinas Pendidikan Kebudayaan Pemuda Dan Olahraga, tercatat sebanyak 74 siswa telah terdaftar di PPLP Provinsi Gorontalo. Pihak pengelola PPLP Provinsi Gorontalo menyampaikan, saat ini PPLP Provinsi Gorontalo memiliki kendala tidak adanya sekolah formal untuk menampung siswa yang berasal dari seluruh daerah yang ada di Provinsi Gorontalo. selain itu tidak adanya sekolah formal membuat pengawasan terhadap atlet tidak maksimal karena atlet harus keluar dari kawasan PPLP untuk pergi ke sekolah-sekolah terdekat.Tujuan PPLP Provinsi Gorontalo adalah untuk menghadirkan sekolah yang dapat menampung siswa berprestasi dibidang olahraga yang ada di provinsi gorontalo, serta memiliki sarana dan prasarana yang mendukung aktifitas pembelajaran dan pelatihan. Metode yang digunakan dalam perancangan ini adalah dengan melakukan observasi lapangan, yaitu dengan meninjau langsung kondisi lapangan dan mengumpulkan data dengan cara mewawancarai pihak terkait, kemudian mengidentifikasi aspek-aspek yang dapat diterapkan dalam perancangan yang menyangkut aspek teknis, aspek desain yang sesuai dengan kriteria perancangan yang akan dicapai. Dari permasalahan yang diperoleh selanjutnya dianalisis sehingga menghasilkan konsep perancangan dengan tema Arsitektur Kontemporer. Sebagai hasil desain yaitu dapat merancang pusat pendidikan dan latihan olahraga dengan segala kegiatan dan sarana prasarana yang mendukung. Hasil laporan berupa konsep perancangan dan penerapan pada objek rancangan sebagai pedoman untuk melanjutkan merancang pusat pendidikan dan latihan olahraga Pelajar.
Evidence for variation in the effective population size of animal mitochondrial DNA
Background: It has recently been shown that levels of diversity in mitochondrial DNA are remarkably constant across animals of diverse census population sizes and ecologies, which has led to the suggestion that the effective population of mitochondrial DNA may be relatively constant. Results: Here we present several lines of evidence that suggest, to the contrary, that the effective population size of mtDNA does vary, and that the variation can be substantial. First, we show that levels of mitochondrial and nuclear diversity are correlated within all groups of animals we surveyed. Second, we show that the effectiveness of selection on non-synonymous mutations, as measured by the ratio of the numbers of non-synonymous and synonymous polymorphisms, is negatively correlated to levels of mitochondrial diversity. Finally, we estimate the effective population size of mitochondrial DNA in selected mammalian groups and show that it varies by at least an order of magnitude. Conclusions: We conclude that there is variation in the effective population size of mitochondria. Furthermore we suggest that the relative constancy of DNA diversity may be due to a negative correlation between the effective population size and the mutation rate per generation
The sonographer’s role in RFA therapy of liver lesions
Interventional techniques using ultrasound guidance, such as Radio Frequency Ablation (RFA) of liver lesions, are the domain of the radiologist. However, real time ultrasound imaging as performed by the sonographer, is critical in monitoring the successful insertion and placement of the RFA needle. RFA is used to create a localised and controlled application of heat in order to induce necrosis of cells within the liver lesions
Fluctuating selection models and Mcdonald-Kreitman type analyses
It is likely that the strength of selection acting upon a mutation varies through time due to changes in the environment. However, most population genetic theory assumes that the strength of selection remains constant. Here we investigate the consequences of fluctuating selection pressures on the quantification of adaptive evolution using McDonald-Kreitman (MK) style approaches. In agreement with previous work, we show that fluctuating selection can generate evidence of adaptive evolution even when the expected strength of selection on a mutation is zero. However, we also find that the mutations, which contribute to both polymorphism and divergence tend, on average, to be positively selected during their lifetime, under fluctuating selection models. This is because mutations that fluctuate, by chance, to positive selected values, tend to reach higher frequencies in the population than those that fluctuate towards negative values. Hence the evidence of positive adaptive evolution detected under a fluctuating selection model by MK type approaches is genuine since fixed mutations tend to be advantageous on average during their lifetime. Never-the-less we show that methods tend to underestimate the rate of adaptive evolution when selection fluctuates
Attributes Enhanced Role-Based Access Control Model
Abstract. Attribute-based access control (ABAC) and role-based access control (RBAC) are currently the two most popular access con-trol models. Yet, they both have known limitations and offer features complimentary to each other. Due to this fact, integration of RBAC and ABAC has recently emerged as an important area of research. In this paper, we propose an access control model that combines the two mod-els in a novel way in order to unify their benefits. Our approach provides a fine-grained access control mechanism that not only takes contextual information into account while making the access control decisions but is also suitable for applications where access to resources is controlled by exploiting contents of the resources in the policy
Self-duality of the D1-D5 near-horizon
We explore fermionic T-duality and self-duality in the geometry AdS3 x S3 x
T4 in type IIB supergravity. We explicitly construct the Killing spinors and
the fermionic T-duality isometries and show that the geometry is self-dual
under a combination of two bosonic AdS3 T-dualities, four fermionic T-dualities
and either two additional T-dualities along T4 or two T-dualities along S3. In
addition, we show that the presence of a B-field acts as an obstacle to
self-duality, a property attributable to S- duality and fermionic T-duality not
commuting. Finally, we argue that fermionic T-duality may be extended to CY2 =
K3, a setting where we cannot explicitly construct the Killing spinors.Comment: 24 pages, references added, changes made to reinforce the point that
S-duality and fermionic T-duality generically do not commute, version
accepted to JHE
Intrinsic and Extrinsic Performance Limits of Graphene Devices on SiO2
The linear dispersion relation in graphene[1,2] gives rise to a surprising
prediction: the resistivity due to isotropic scatterers (e.g. white-noise
disorder[3] or phonons[4-8]) is independent of carrier density n. Here we show
that acoustic phonon scattering[4-6] is indeed independent of n, and places an
intrinsic limit on the resistivity in graphene of only 30 Ohm at room
temperature (RT). At a technologically-relevant carrier density of 10^12 cm^-2,
the mean free path for electron-acoustic phonon scattering is >2 microns, and
the intrinsic mobility limit is 2x10^5 cm^2/Vs, exceeding the highest known
inorganic semiconductor (InSb, ~7.7x10^4 cm^2/Vs[9]) and semiconducting carbon
nanotubes (~1x10^5 cm^2/Vs[10]). We also show that extrinsic scattering by
surface phonons of the SiO2 substrate[11,12] adds a strong temperature
dependent resistivity above ~200 K[8], limiting the RT mobility to ~4x10^4
cm^2/Vs, pointing out the importance of substrate choice for graphene
devices[13].Comment: 16 pages, 3 figure
VEZF1 elements mediate protection from DNA methylation
There is growing consensus that genome organization and long-range gene regulation involves partitioning of the genome into domains of distinct epigenetic chromatin states. Chromatin insulator or barrier elements are key components of these processes as they can establish boundaries between chromatin states. The ability of elements such as the paradigm β-globin HS4 insulator to block the range of enhancers or the spread of repressive histone modifications is well established. Here we have addressed the hypothesis that a barrier element in vertebrates should be capable of defending a gene from silencing by DNA methylation. Using an established stable reporter gene system, we find that HS4 acts specifically to protect a gene promoter from de novo DNA methylation. Notably, protection from methylation can occur in the absence of histone acetylation or transcription. There is a division of labor at HS4; the sequences that mediate protection from methylation are separable from those that mediate CTCF-dependent enhancer blocking and USF-dependent histone modification recruitment. The zinc finger protein VEZF1 was purified as the factor that specifically interacts with the methylation protection elements. VEZF1 is a candidate CpG island protection factor as the G-rich sequences bound by VEZF1 are frequently found at CpG island promoters. Indeed, we show that VEZF1 elements are sufficient to mediate demethylation and protection of the APRT CpG island promoter from DNA methylation. We propose that many barrier elements in vertebrates will prevent DNA methylation in addition to blocking the propagation of repressive histone modifications, as either process is sufficient to direct the establishment of an epigenetically stable silent chromatin stat
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