20 research outputs found

    Pembuatan Alat Peraga Lemari Pendingin Sebagai Media Pembelajaran Mata Kuliah Teknik Pendingin Di Universitas Negeri Semarang

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    — Media pembelajaran merupakan segala fisik yang menyajikan pesan serta perangsang peserta didik untuk belajar, sehingga keberadaan media pembelajaran penting untuk membantu dalam proses belajar mengajar. Alat peraga adalah salah satu media pembelajaran, dengan memanfaatkan alat peraga proses pembelajaran akan dapat mempermudah dalam memahami materi yang dipelajari oleh mahasiswa, karena ditampilkan dalam bentuk nyata. Teknik Pendingin adalah salah satu mata kuliah yang ada pada Prodi Pendidikan Teknik Elektro. Permasalahannya apakah alat peraga lemari pendingin layak sebagai media pembelajaran pada mata kuliah Teknik Pendingin jurusan Teknik Elektro Universitas Negeri Semarang. Untuk itu perlu diadakan penelitian untuk mengetahui apakah alat peraga lemari pendingin ini layak untuk dignakan sebagai media pembelajaran. Data dikumpulkan dengan metode angket tertutup maupun terbuka. Alat peraga lemari pendingin ini diujicoba oleh dosen ahli materi teknik pendingin. Metode analisis yang digunakan adalah metode analisis statistik deskriptif. Menurut hasil penelitian dari responden secara keseluruhan, alat peraga lemari pendingin pada mata kuliah Teknik Pendingin ini layak digunakan sebagai media pembelajaran. Dosen ahli materi mengemukakan alat peraga ini layak dijadikan alat peraga setelah adanya revisi alat. Berdasarkan dari hasil penelitian dan pembahasan, dapat disimpulkan bahwa menurut mahasiswa media pembelajaran yang berupa alat peraga lemari pendingin pada mata kuliah Teknik Pendingin diwujudkan dengan menyusun prosedur kerja dengan langkah-langkah sebagai berikut: perencanaan alat peraga, penyediaan alat dan bahan, pembuatan alat peraga, validasi alat peraga, uji coba alat peraga, dan evaluasi. Dari hasil penelitian yang telah dilakukan kepada mahasiswa dengan beberapa aspek, alat peraga lemari pendingin ini termasuk dalam kategori layak, sehingga alat peraga ini dapat digunakan sebagai media pembelajaran. Namun masih terdapat kekurangan pada bahan penutup yang dugunakan seharusnya tidak menggunakan kaca agar tidah mudah pecah, dan jika menggunakan kaca suhu yang ada di dalam lemari pendingin masih dapat terpengaruh oleh suhu udara luar. Kata kunci— Media Pembelajaran, teknik pendingin, universitas negeri semarang, alat peraga, lemari pendingi

    c-Myc Is a Universal Amplifier of Expressed Genes in Lymphocytes and Embryonic Stem Cells

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    SummaryThe c-Myc HLH-bZIP protein has been implicated in physiological or pathological growth, proliferation, apoptosis, metabolism, and differentiation at the cellular, tissue, or organismal levels via regulation of numerous target genes. No principle yet unifies Myc action due partly to an incomplete inventory and functional accounting of Myc’s targets. To observe Myc target expression and function in a system where Myc is temporally and physiologically regulated, the transcriptomes and the genome-wide distributions of Myc, RNA polymerase II, and chromatin modifications were compared during lymphocyte activation and in ES cells as well. A remarkably simple rule emerged from this quantitative analysis: Myc is not an on-off specifier of gene activity, but is a nonlinear amplifier of expression, acting universally at active genes, except for immediate early genes that are strongly induced before Myc. This rule of Myc action explains the vast majority of Myc biology observed in literature

    Phosphorylation of H4 Ser 47 promotes HIRA-mediated nucleosome assembly

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    Histone H3 variant H3.3, while differing from canonical H3 (H3.1) by only five amino acids, is assembled into nucleosomes, along with histone H4, at genic regions by the histone chaperone HIRA, whereas H3.1 is assembled into nucleosomes in a CAF-1-dependent reaction. Here, we show that phosphorylation of histone H4 Ser 47 (H4S47ph), catalyzed by the PAK2 kinase, promotes nucleosome assembly of H3.3–H4 and inhibits nucleosome assembly of H3.1–H4 by increasing the binding affinity of HIRA to H3.3–H4 and reducing association of CAF-1 with H3.1–H4. These results reveal a mechanism whereby H4S47ph distinctly regulates nucleosome assembly of H3.1 and H3.3

    Evolutionary Analysis of <i>GH3</i> Genes in Six <i>Oryza</i> Species/Subspecies and Their Expression under Salinity Stress in <i>Oryza sativa</i> ssp. <i>japonica</i>

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    Glycoside Hydrolase 3 (GH3), a member of the Auxin-responsive gene family, is involved in plant growth, the plant developmental process, and various stress responses. The GH3 gene family has been well-studied in Arabidopsis thaliana and Zea mays. However, the evolution of the GH3 gene family in Oryza species remains unknown and the function of the GH3 gene family in Oryza sativa is not well-documented. Here, a systematic analysis was performed in six Oryza species/subspecies, including four wild rice species and two cultivated rice subspecies. A total of 13, 13, 13, 13, 12, and 12 members were identified in O. sativa ssp. japonica, O. sativa ssp. indica, Oryza rufipogon, Oryza nivara, Oryza punctata, and Oryza glumaepatula, respectively. Gene duplication events, structural features, conserved motifs, a phylogenetic analysis, chromosome locations, and Ka/Ks ratios of this important family were found to be strictly conservative across these six Oryza species/subspecies, suggesting that the expansion of the GH3 gene family in Oryza species might be attributed to duplication events, and this expansion could occur in the common ancestor of Oryza species, even in common ancestor of rice tribe (Oryzeae) (23.07~31.01 Mya). The RNA-seq results of different tissues displayed that OsGH3 genes had significantly different expression profiles. Remarkably, the qRT-PCR result after NaCl treatment indicated that the majority of OsGH3 genes play important roles in salinity stress, especially OsGH3-2 and OsGH3-8. This study provides important insights into the evolution of the GH3 gene family in Oryza species and will assist with further investigation of OsGH3 genes&#8217; functions under salinity stress

    Expansion and Evolutionary Patterns of Glycosyltransferase Family 8 in Gramineae Crop Genomes and Their Expression under Salt and Cold Stresses in <i>Oryza sativa</i> ssp. <i>japonica</i>

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    Plant cell walls play a fundamental role in several ways, providing structural support for cells, resistance against pathogens and facilitating the communication between cells. The glycosyltransferase family 8 (GT8) is involved in the formation of the plant cell wall. However, the evolutionary relationship and the functional differentiation of this important gene family remain obscure in Gramineae crop genomes. In the present investigation, we identified 269 GT8 genes in the seven Gramineae representative crop genomes, namely, 33 in Hordeum vulgare, 37 in Brachypodium distachyon, 40 in Oryza sativa ssp. japonica, 41 in Oryza rufipogon, 36 in Setaria italica, 37 in Sorghum bicolor, and 45 in Zea mays. Phylogenetic analysis suggested that all identified GT8 proteins belonged to seven subfamilies: galacturonosyltransferase (GAUT), galacturonosyltransferase-like (GATL), GATL-related (GATR), galactinol synthase (GolS), and plant glycogenin-like starch initiation proteins A (PGSIP-A), PGSIP-B, and PGSIP-C. We estimated that the GAUT subfamily might be further divided into four subgroups (I&#8211;IV) due to differentiation of gene structures and expression patterns. Our orthogroup analysis identified 22 orthogroups with different sizes. Of these orthogroups, several orthogroups were lost in some species, such as S. italica and Z. mays. Moreover, lots of duplicate pairs and collinear pairs were discovered among these species. These results indicated that multiple duplication modes led to the expansion of this important gene family and unequal loss of orthogroups and subfamilies might have happened during the evolutionary process. RNA-seq, microarray analysis, and qRT-PCR analyses indicated that GT8 genes are critical for plant growth and development, and for stresses responses. We found that OsGolS1 was significantly up-regulated under salt stress, while OsGAUT21, OsGATL2, and OsGATL5 had remarkable up-regulation under cold stress. The current study highlighted the expansion and evolutionary patterns of the GT8 gene family in these seven Gramineae crop genomes and provided potential candidate genes for future salt- and cold- resistant molecular breeding studies in O. sativa

    Induction of DNMT3B by PGE2 and IL6 at Distant Metastatic Sites Promotes Epigenetic Modification and Breast Cancer Colonization

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    Current cancer treatments are largely based on the genetic characterization of primary tumors and are ineffective for metastatic disease. Here we report that DNA methyltransferase 3B (DNMT3B) is induced at distant metastatic sites and mediates epigenetic reprogramming of metastatic tumor cells. Multiomics analysis and spontaneous metastatic mouse models revealed that DNMT3B alters multiple pathways including STAT3, NFκB, PI3K/Akt, β-catenin, and Notch signaling, which are critical for cancer cell survival, apoptosis, proliferation, invasion, and colonization. PGE2 and IL6 were identified as critical inflammatory mediators in DNMT3B induction. DNMT3B expression levels positively correlated with human metastatic progression. Targeting IL6 or COX-2 reduced DNMT3B induction and improved chemo or PD1 therapy. We propose a novel mechanism linking the metastatic microenvironment with epigenetic alterations that occur at distant sites. These results caution against the Achilles heel in cancer therapies based on primary tumor characterization and suggests targeting DNMT3B induction as new option for treating metastatic disease. SIGNIFICANCE: These findings reveal that DNMT3B epigenetically regulates multiple pro-oncogenic signaling pathways via the inflammatory microenvironment at distant sites, cautioning the clinical approach basing current therapies on genetic characterization of primary tumors
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