Variational bounds on the energy dissipation rate in body-forced shear flow

A new variational problem for upper bounds on the rate of energy dissipation in body-forced shear flows is formulated by including a balance parameter in the derivation from the Navier-Stokes equations. The resulting min-max problem is investigated computationally, producing new estimates that quantitatively improve previously obtained rigorous bounds. The results are compared with data from direct numerical simulations.Comment: 15 pages, 7 figure

Variational bound on energy dissipation in turbulent shear flow

We present numerical solutions to the extended Doering-Constantin variational principle for upper bounds on the energy dissipation rate in plane Couette flow, bridging the entire range from low to asymptotically high Reynolds numbers. Our variational bound exhibits structure, namely a pronounced minimum at intermediate Reynolds numbers, and recovers the Busse bound in the asymptotic regime. The most notable feature is a bifurcation of the minimizing wavenumbers, giving rise to simple scaling of the optimized variational parameters, and of the upper bound, with the Reynolds number.Comment: 4 pages, RevTeX, 5 postscript figures are available as one .tar.gz file from [email protected]

The space station: Human factors and productivity

Human factor researchers and engineers are making inputs into the early stages of the design of the Space Station to improve both the quality of life and work on-orbit. Effective integration of the human factors information related to various Intravehicular Activity (IVA), Extravehicular Activity (EVA), and teletobotics systems during the Space Station design will result in increased productivity, increased flexibility of the Space Stations systems, lower cost of operations, improved reliability, and increased safety for the crew onboard the Space Station. The major features of productivity examined include the cognitive and physical effort involved in work, the accuracy of worker output and ability to maintain performance at a high level of accuracy, the speed and temporal efficiency with which a worker performs, crewmember satisfaction with their work environment, and the relation between performance and cost

An AUC-based Permutation Variable Importance Measure for Random Forests

The random forest (RF) method is a commonly used tool for classification with high dimensional data as well as for ranking candidate predictors based on the so-called random forest variable importance measures (VIMs). However the classification performance of RF is known to be suboptimal in case of strongly unbalanced data, i.e. data where response class sizes differ considerably. Suggestions were made to obtain better classification performance based either on sampling procedures or on cost sensitivity analyses. However to our knowledge the performance of the VIMs has not yet been examined in the case of unbalanced response classes. In this paper we explore the performance of the permutation VIM for unbalanced data settings and introduce an alternative permutation VIM based on the area under the curve (AUC) that is expected to be more robust towards class imbalance. We investigated the performance of the standard permutation VIM and of our novel AUC-based permutation VIM for different class imbalance levels using simulated data and real data. The results suggest that the standard permutation VIM loses its ability to discriminate between associated predictors and predictors not associated with the response for increasing class imbalance. It is outperformed by our new AUC-based permutation VIM for unbalanced data settings, while the performance of both VIMs is very similar in the case of balanced classes. The new AUC-based VIM is implemented in the R package party for the unbiased RF variant based on conditional inference trees. The codes implementing our study are available from the companion website: http://www.ibe.med.uni-muenchen.de/organisation/mitarbeiter/070_drittmittel/janitza/index.html

Analisis Kesiapan Pemerintah Provinsi Kalimantan Tengah dalam Wacana Pemindahan Ibu Kota Negara Republik Indonesia ke Kota Palangkaraya

Artikel ini merupakan hasil studi lapangan yang terkait dengan wacana pemindahan Ibu Kota Republik Indonesia dari Jakarta ke Palangkaraya. Secara umum, pemerintah daerah Kalimantan Tengah menyatakan kesiapan dan persetujuan terkait wacana  yang digulirkan oleh pemerintah pusat tersebut, namun gubernur Provinsi Kalteng mengingatkan ada beberapa hal yang perlu untuk diperhatikan jika wacana tersebut benar-benar akan diwujudkan. Beberapa persoalan pokok tersebut adalah kesiapan anggaran untuk pembangunan infrastruktur, perencanaan tata ruang wilayah yang baik, perencanaan kesiapan SDM, dan aspek-aspek sosial budaya yang perlu untuk menjadi perhatian. Studi ini dilakukan dengan wawancara mendalam terhadap beberapa informan serta analisis dokumentatif baik yang bersumber dari surat kabar, pemberitaan-pemberitaan di radio maupun di televisi dan studi lapangan oleh peneliti. Studi ini menyimpulkan bahwa, meskipun pemerintah daerah Kalteng  sudah  menyatakan  kesiapannya,  namun  banyak  faktor  yang  perlu untuk diperhatikan, terutama aspek sosial, politik, birokrasi, dan daya dukung lingkungan hidup. Peneliti menyimpulkan bahwa perlu dilakukan kajian mendalam terkait dengan perencanaan tersebut agar tidak menimbulkan permasalahan di kemudian hari

An evolutionary analysis of cAMP-specific Phosphodiesterase 4 alternative splicing

<p>Abstract</p> <p>Background</p> <p>Cyclic nucleotide phosphodiesterases (PDEs) hydrolyze the intracellular second messengers: cyclic adenosine monophosphate (cAMP) and cyclic guanine monophosphate (cGMP). The cAMP-specific PDE family 4 (PDE4) is widely expressed in vertebrates. Each of the four PDE4 gene isoforms (PDE4 A-D) undergo extensive alternative splicing via alternative transcription initiation sites, producing unique amino termini and yielding multiple splice variant forms from each gene isoform termed long, short, super-short and truncated super-short. Many species across the vertebrate lineage contain multiple splice variants of each gene type, which are characterized by length and amino termini.</p> <p>Results</p> <p>A phylogenetic approach was used to visualize splice variant form genesis and identify conserved splice variants (genome conservation with EST support) across the vertebrate taxa. Bayesian and maximum likelihood phylogenetic inference indicated PDE4 gene duplication occurred at the base of the vertebrate lineage and reveals additional gene duplications specific to the teleost lineage. Phylogenetic inference and PDE4 splice variant presence, or absence as determined by EST screens, were further supported by the genomic analysis of select vertebrate taxa. Two conserved PDE4 long form splice variants were found in each of the PDE4A, PDE4B, and PDE4C genes, and eight conserved long forms from the PDE4 D gene. Conserved short and super-short splice variants were found from each of the PDE4A, PDE4B, and PDE4 D genes, while truncated super-short variants were found from the PDE4C and PDE4 D genes. PDE4 long form splice variants were found in all taxa sampled (invertebrate through mammals); short, super-short, and truncated super-short are detected primarily in tetrapods and mammals, indicating an increasing complexity in both alternative splicing and cAMP metabolism through vertebrate evolution.</p> <p>Conclusions</p> <p>There was a progressive independent incorporation of multiple PDE4 splice variant forms and amino termini, increasing PDE4 proteome complexity from primitive vertebrates to humans. While PDE4 gene isoform duplicates with limited alternative splicing were found in teleosts, an expansion of both PDE4 splice variant forms, and alternatively spliced amino termini predominantly occurs in mammals. Since amino termini have been linked to intracellular targeting of the PDE4 enzymes, the conservation of amino termini in PDE4 splice variants in evolution highlights the importance of compartmentalization of PDE4-mediated cAMP hydrolysis.</p

Pergeseran Paradigma Pembelajaran Informatika di Sekolah

Pembelajaran sekolah mengalami perkembangan sesuai zaman. Perubahan paradigma Pembelajaran diformulasikan ke dalam Kurikulum sekolah demi terwujudnya Pendidikan yang berkualitas. Strategi pembelajaran &nbsp;kontekstual diperlukan untuk memenuhi kebutuhan belajar peserta didik. Informatika merupakan mata pelajaran yang mengalami perubahan seiring perkembangan teknologi. Tulisan ini mendeskripsikan bagaimana pergeseran paradigma pembelajaran dari TIK menjadi Informatika di Sekolah. Untuk memperoleh paradigma pembelajaran Informatika dalam implementasi Kurikulum Merdeka sekarang secara komprehensif dilakukan pendekatan penelitian kualitatif yang menggunakan metode studi Pustaka, observasi dan wawancara. &nbsp;Observasi peneliti dilakukan secara langsung di lapangan dan melibatkan bagian kurikulum serta guru. Guru yang dimaksudkan di sini adalah guru yang mengalami langsung proses pembelajaran sesuai kurikulum yang lama, yakni Kurikulum 2013 dan kurikulum baru, yakni Kurikulum Merdeka yang secara khusus di satuan pendidikan Sekolah Menengah Atas yang ada di provinsi Sulawesi Utara. Berdasarkan observasi lapangan, studi dokumentasi dan wawancara bahwa terjadi pergeseran paradigma pembelajaran Informatika di sekolah. Pembelajaran Informatika menggantikan pembelajaran TIK, karena dipandang adanya perluasan dan pendalaman materi.&nbsp; Informatika mencakup aspek-aspek pembelajaran yang disesuaikan dengan perkembangan teknologi terkini yang begitu pesat

Variational bound on energy dissipation in plane Couette flow

We present numerical solutions to the extended Doering-Constantin variational principle for upper bounds on the energy dissipation rate in turbulent plane Couette flow. Using the compound matrix technique in order to reformulate this principle's spectral constraint, we derive a system of equations that is amenable to numerical treatment in the entire range from low to asymptotically high Reynolds numbers. Our variational bound exhibits a minimum at intermediate Reynolds numbers, and reproduces the Busse bound in the asymptotic regime. As a consequence of a bifurcation of the minimizing wavenumbers, there exist two length scales that determine the optimal upper bound: the effective width of the variational profile's boundary segments, and the extension of their flat interior part.Comment: 22 pages, RevTeX, 11 postscript figures are available as one uuencoded .tar.gz file from [email protected]

Tingkat Penggunaan Teknologi Informasi dan Dampaknya pada Kreativitas Pembelajaran Guru-guru Sekolah Luar Biasa di Provinsi Sulawesi Utara Indonesia

Penelitian ini bertujuan untuk menganalisis tingkat penggunaan teknologi informasi dan dampaknya pada kreativitas pembelajaran guru-guru sekolah luar biasa di Provinsi Sulawesi Utara. Penelitian ini menggunakan metode penelitian deskriptif. Metode ini dapat digunakan untuk mendeskripsikan, menginterpretasikan suatu fenomena. Data yang digunakan adalah data sekunder yang diambil dari teori-teori terkait. Berdasarkan hasil analisis dapat disimpulkan bahwa dari 335 guru SLB di Provinsi Sulawesi Utara hanya 263 orang guru yang menguasai IT, sementara sisanya 72 orang belum menguasai IT.&nbsp; Usia guru SLB di Prov. Sulawesi Utara terbanyak berusia kurang dari 30 tahun dengan jumlah perempuan 57 orang dan laki-laki 21 orang. Sementara persentase usia diatas 55 tahun sebanyak 16 orang perempuan dan 8 orang laki-laki. Hal ini menjukkan bahwa usia guru tingkat pemahaman IT oleh guru yang berusia lebih muda lebih mendominasi dikarenakan mereka lahir dan tumbuh di tengah-tengah perkembangan IT secara global

Relación entre la composición química corporal, la fertilidad y la prolificidad en conejas primíparas.

En este trabajo se ha estudiado el efecto de la composición química corporal, estimada mediante el método de impedancia bioeléctrica (BIA) en la primera y segunda inseminación artificial (IA), sobre la fertilidad y la prolificidad de conejas primíparas. Se utilizaron los datos de 137 conejas procedentes de dos granjas que utilizaban dos genéticas distintas (UPV e Hyplus) y tres ritmos reproductivos (R4: inseminación a los 4 días tras el parto y destete a los 28 días, R11: inseminación a los 11 días postparto y destete a 35 días y R14: inseminación a los 14 días tras el parto y destete a los 42 días). La fertilidad media observada en el segundo parto fue de un 56,2% y el porcentaje de nacidos vivos, sobre los nacidos totales, fue de un 87,5%, no encontrándose diferencias entre los ritmos utilizados. El aumento de la proporción de proteína corporal, grasa y energía en la primera IA tuvieron un efecto positivo (P=0,007; P=0,03 y P<0,001, respectivamente) sobre la fertilidad del segundo parto. Igualmente, un mayor contenido en grasa (P<0,001) y energía (P<0,001) en la segunda IA también incrementaron la fertilidad del segundo parto. El incremento del ratio proteína/energía corporal de las conejas, determinado en las dos IA, tuvo un efecto negativo sobre la fertilidad en el segundo parto (P<0,001), observándose mejores resultados en conejas con 12 g proteína/MJ respecto a otras con valores superiores. El porcentaje de nacidos vivos (P<0,001), sobre los nacidos totales, aumentó con la proporción de proteína de las conejas en el momento de la segunda IA, pero esta última no tuvo efecto sobre la fertilidad. This study evaluated the effect of chemical body composition at first and second artificial inseminations (AI), determined by bioelectric impedance technique (BIA), on fertility and prolificacy of primiparous rabbit does. Data of 137 does from two farms using two different genetics (UPV and Hyplus) and three breeding systems were analyzed. Fertility was 56.2 % and the percentage of kits born alive over total born was 87.5 %. Breeding system had no effect on fertility or the percentage of kits born alive. Higher body protein, fat and energy of the rabbit doe at first artificial insemination (AI) increased the fertility in the second parity (P=0.007, P=0.03 and P<0.001 respectively). Fat and energy content of the doe at the second AI affected positively fertility in the second parity (P<0.001 and P<0.001 respectively), while protein influenced positively only prolificacy (P<0.001). The increase of the ratio protein/energy in both AI moments had a negative influence on fertility in the second parity (P<0.001), rabbit does with 12 g protein/MJ showed a higher fertility than those with higher value