633 research outputs found
Pengembangan Lembar Kegiatan Siswa (Lks) Kimia Sma/ma Berbasis Learning Cycle 5e Pada Materi Laju Reaksi
Penelitian ini bertujuan untuk: (1) mengembangkan Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E, (2) mengetahui kualitas Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E, (3) mengetahui efektivitas Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E untuk meningkatkan prestasi belajar siswa. Penelitian dan pengembangan Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E menggunakan prosedur penelitian dan pengembangan dari Borg and Gall yang disederhanakan menjadi 9 tahapan yaitu: (1) penelitian pendahuluan dan pengumpulan data, (2) perencanaan, (3) pengembangan produk, (4) uji coba lapangan awal, (5) revisi produk awal, (6) uji coba pelaksanaan lapangan, (7) penyempurnaan produk hasil uji coba lapangan, (8) uji coba pelaksanaan lapangan, (9) penyempurnaan produk akhir. Analisis Data yang digunakan adalah analisis deskriptif kualitatif. Hasil Penelitian menunjukkan: (1) telah berhasil dikembangkan Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E pada materi Laju Reaksi yang dilakukan berdasarkan tahapan penelitian dan pengembangan R&D yang terdiri dari 9 tahapan, (2) kualitas Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E pada materi Laju Reaksi memiliki kualitas sangat baik pada aspek komponen kelayakan isi, bahasa, penyajian dan kegrafisan dengan persentase sebesar 84,06% berdasarkan penilaian siswa dan 90,88% berdasarkan penilaian guru, (hasil uji efektivitas pada aspek pengetahuan terdapat perbedaan antara kelas eksperimen (pembelajaran dengan menggunakan model Learning Cycle 5E disertai Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E ) dan kelas baseline (pembelajaran dengan menggunakan model pembelajaran Learning Cycle 5E tanpa disertai Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E ),, sedangkan pada aspek sikap dan keterampilan tidak terdapat perbedaan
Refactoring GrPPI:Generic Refactoring for Generic Parallelism in C++
Funding: EU Horizon 2020 project, TeamPlay (https://www.teamplay-xh2020.eu), Grant Number 779882, UK EPSRC Discovery, grant number EP/P020631/1, and Madrid Regional Government, CABAHLA-CM (ConvergenciA Big dAta-Hpc: de Los sensores a las Aplicaciones) Grant Number S2018/TCS-4423.The Generic Reusable Parallel Pattern Interface (GrPPI) is a very useful abstraction over different parallel pattern libraries, allowing the programmer to write generic patterned parallel code that can easily be compiled to different backends such as FastFlow, OpenMP, Intel TBB and C++ threads. However, rewriting legacy code to use GrPPI still involves code transformations that can be highly non-trivial, especially for programmers who are not experts in parallelism. This paper describes software refactorings to semi-automatically introduce instances of GrPPI patterns into sequential C++ code, as well as safety checking static analysis mechanisms which verify that introducing patterns into the code does not introduce concurrency-related bugs such as race conditions. We demonstrate the refactorings and safety-checking mechanisms on four simple benchmark applications, showing that we are able to obtain, with little effort, GrPPI-based parallel versions that accomplish good speedups (comparable to those of manually-produced parallel versions) using different pattern backends.Publisher PDFPeer reviewe
Migraine aura: retracting particle-like waves in weakly susceptible cortex
Cortical spreading depression (SD) has been suggested to underlie migraine aura. Despite a precise match in speed, the spatio-temporal patterns of SD and aura symptoms on the cortical surface ordinarily differ in aspects of size and shape. We show that this mismatch is reconciled by utilizing that both pattern types bifurcate from an instability point of generic reaction-diffusion models. To classify these spatio-temporal pattern we suggest a susceptibility scale having the value [sigma]=1 at the instability point. We predict that human cortex is only weakly susceptible to SD ([sigma]<1), and support this prediction by directly matching visual aura symptoms with anatomical landmarks using fMRI retinotopic mapping. We discuss the increased dynamical repertoire of cortical tissue close to [sigma]=1, in particular, the resulting implications on migraine pharmacology that is hitherto tested in the regime ([sigma]>>1), and potentially silent aura occurring below a second bifurcation point at [sigma]=0 on the susceptible scale
Low-grade oligodendroglioma of the pineal gland: a case report and review of the literature
<p>Abstract</p> <p>Background</p> <p>Gliomas are a very rare subtype of pineal region tumours, whereas oligodendrogliomas of the pineal region are exceedingly rare, since there have been only 3 cases of anaplastic oligodedrogliomas reported this far.</p> <p>Methods-Results</p> <p>We present a case of a low-grade oligodendroglioma arising in the pineal gland of a 37 year-old woman. The patient presented with diplopia associated with a cystic pineal region mass demonstrated on MRI. Total resection was performed and histological examination showed that the cystic wall consisted of tumour cells with a central nucleus a perinuclear halo and minimal pleomorphism. Immnunohistochemical analysis showed that these cells were diffusely positive for CD57, and negative for GFAP, CD10, CD99, cytokeratins, neurofilaments and synaptophysin. FISH analysis was performed in a small number of neoplastic cells, which were not exhausted after immunohistochemistry and did not reveal deletion of 1p and 19q chromosome arms. However, the diagnosis of a low grade oligodendroglioma of the pineal gland was assigned.</p> <p>Conclusion</p> <p>Although the spectrum of tumours arising in the pineal gland is broad, the reports of oligodendrogliomas confined to this location are exceedingly rare, and to the best of our knowledge there is no report of a low-grade oligodendroglioma. However, they should be added in the long list of tumours arising in the pineal gland.</p
Intrapopulation Variability Shaping Isotope Discrimination and Turnover: Experimental Evidence in Arctic Foxes
Tissue-specific stable isotope signatures can provide insights into the trophic ecology of consumers and their roles in food webs. Two parameters are central for making valid inferences based on stable isotopes, isotopic discrimination (difference in isotopic ratio between consumer and its diet) and turnover time (renewal process of molecules in a given tissue usually measured when half of the tissue composition has changed). We investigated simultaneously the effects of age, sex, and diet types on the variation of discrimination and half-life in nitrogen and carbon stable isotopes (δ15N and δ13C, respectively) in five tissues (blood cells, plasma, muscle, liver, nail, and hair) of a top predator, the arctic fox Vulpes lagopus. We fed 40 farmed foxes (equal numbers of adults and yearlings of both sexes) with diet capturing the range of resources used by their wild counterparts. We found that, for a single species, six tissues, and three diet types, the range of discrimination values can be almost as large as what is known at the scale of the whole mammalian or avian class. Discrimination varied depending on sex, age, tissue, and diet types, ranging from 0.3‰ to 5.3‰ (mean = 2.6‰) for δ15N and from 0.2‰ to 2.9‰ (mean = 0.9‰) for δ13C. We also found an impact of population structure on δ15N half-life in blood cells. Varying across individuals, δ15N half-life in plasma (6 to 10 days) was also shorter than for δ13C (14 to 22 days), though δ15N and δ13C half-lives are usually considered as equal. Overall, our multi-factorial experiment revealed that at least six levels of isotopic variations could co-occur in the same population. Our experimental analysis provides a framework for quantifying multiple sources of variation in isotopic discrimination and half-life that needs to be taken into account when designing and analysing ecological field studies
A Novel Mutation in LEPRE1 That Eliminates Only the KDEL ER- Retrieval Sequence Causes Non-Lethal Osteogenesis Imperfecta
Prolyl 3-hydroxylase 1 (P3H1), encoded by the LEPRE1 gene, forms a molecular complex with cartilage-associated protein (CRTAP) and cyclophilin B (encoded by PPIB) in the endoplasmic reticulum (ER). This complex is responsible for one step in collagen post-translational modification, the prolyl 3-hydroxylation of specific proline residues, specifically α1(I) Pro986. P3H1 provides the enzymatic activity of the complex and has a Lys-Asp-Glu-Leu (KDEL) ER-retrieval sequence at the carboxyl terminus. Loss of function mutations in LEPRE1 lead to the Pro986 residue remaining unmodified and lead to slow folding and excessive helical post-translational modification of type I collagen, which is seen in both dominant and recessive osteogenesis imperfecta (OI). Here, we present the case of siblings with non-lethal OI due to novel compound heterozygous mutations in LEPRE1 (c.484delG and c.2155dupC). The results of RNA analysis and real-time PCR suggest that mRNA with c.2155dupC escapes from nonsense-mediated RNA decay. Without the KDEL ER- retrieval sequence, the product of the c.2155dupC variant cannot be retained in the ER. This is the first report of a mutation in LEPRE1 that eliminates only the KDEL ER-retrieval sequence, whereas other functional domains remain intact. Our study shows, for the first time, that the KDEL ER- retrieval sequence is essential for P3H1 functionality and that a defect in KDEL is sufficient for disease onset
The Influence of Coastal Access on Isotope Variation in Icelandic Arctic Foxes
To quantify the ecological effects of predator populations, it is important to evaluate how population-level specializations are dictated by intra- versus inter-individual dietary variation. Coastal habitats contain prey from the terrestrial biome, the marine biome and prey confined to the coastal region. Such habitats have therefore been suggested to better support predator populations compared to habitats without coastal access. We used stable isotope data on a small generalist predator, the arctic fox, to infer dietary strategies between adult and juvenile individuals with and without coastal access on Iceland. Our results suggest that foxes in coastal habitats exhibited a broader isotope niche breadth compared to foxes in inland habitats. This broader niche was related to a greater diversity of individual strategies rather than to a uniform increase in individual niche breadth or by individuals retaining their specialization but increasing their niche differentiation. Juveniles in coastal habitats exhibited a narrower isotope niche breadth compared to both adults and juveniles in inland habitats, and juveniles in inland habitats inhabited a lower proportion of their total isotope niche compared to adults and juveniles from coastal habitats. Juveniles in both habitats exhibited lower intra-individual variation compared to adults. Based on these results, we suggest that foxes in both habitats were highly selective with respect to the resources they used to feed offspring, but that foxes in coastal habitats preferentially utilized marine resources for this purpose. We stress that coastal habitats should be regarded as high priority areas for conservation of generalist predators as they appear to offer a wide variety of dietary options that allow for greater flexibility in dietary strategies
Second law, entropy production, and reversibility in thermodynamics of information
We present a pedagogical review of the fundamental concepts in thermodynamics
of information, by focusing on the second law of thermodynamics and the entropy
production. Especially, we discuss the relationship among thermodynamic
reversibility, logical reversibility, and heat emission in the context of the
Landauer principle and clarify that these three concepts are fundamentally
distinct to each other. We also discuss thermodynamics of measurement and
feedback control by Maxwell's demon. We clarify that the demon and the second
law are indeed consistent in the measurement and the feedback processes
individually, by including the mutual information to the entropy production.Comment: 43 pages, 10 figures. As a chapter of: G. Snider et al. (eds.),
"Energy Limits in Computation: A Review of Landauer's Principle, Theory and
Experiments
Inhibition of NOS- like activity in maize alters the expression of genes involved in H2O2 scavenging and glycine betaine biosynthesis
Nitric oxide synthase-like activity contributes to the production of nitric oxide in plants, which controls
plant responses to stress. This study investigates if changes in ascorbate peroxidase enzymatic
activity and glycine betaine content in response to inhibition of nitric oxide synthase-like activity are
associated with transcriptional regulation by analyzing transcript levels of genes (betaine aldehyde
dehydrogenase) involved in glycine betaine biosynthesis and those encoding antioxidant enzymes
(ascorbate peroxidase and catalase) in leaves of maize seedlings treated with an inhibitor of nitric
oxide synthase-like activity. In seedlings treated with a nitric oxide synthase inhibitor, transcript levels
of betaine aldehyde dehydrogenase were decreased. In plants treated with the nitric oxide synthase
inhibitor, the transcript levels of ascorbate peroxidase-encoding genes were down-regulated. We thus
conclude that inhibition of nitric oxide synthase-like activity suppresses the expression of ascorbate
peroxidase and betaine aldehyde dehydrogenase genes in maize leaves. Furthermore, catalase activity
was suppressed in leaves of plants treated with nitric oxide synthase inhibitor; and this corresponded
with the suppression of the expression of catalase genes. We further conclude that inhibition of nitric
oxide synthase-like activity, which suppresses ascorbate peroxidase and catalase enzymatic activities,
results in increased H2O2 content
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