157 research outputs found

    Studi Perbandingan Karakteristik Agregat Quarry Nangapanda Dan Quarry Aemau Untuk Lapis Pondasi Bawah (Sub Base)

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    Salah satu bahan penyusun perkerasan jalan adalah agregat,untuk itu perlu dilakukan penelitian terhadap karakteristik material agregat sebagai bahan dasar konstruksi jalan. Quarry Nangapanda dan quarry Aemau merupakan sumber material yang sering digunakan untuk pembangunan pekerjaan jalan di Kabupaten Ende dan Nagekeo. Tujuan Penelitian ini untuk mengetahui karakteristik agregat quarry Nangapanda dan quarry Aemau, serta perbandingan karakteristiknya untuk lapis pondasi bawah (sub base). Metode yang digunakan adalah Standar Nasional Indonesia (SNI). Hasil pengujian analisis saringan agregat dua quarry ini termasuk dalam tipikal gradasi seragam,berat jenis (bulk) quarry Nangapanda sebesar 2,53 dan quarry Aemau sebesar 2,84. Penyerapan (absorption) untuk quarry Nangapanda sebesar 2,81% dan quarry Aemau sebesar 1,60%,kadar air agregat quarry Nangapanda sebesar 1,51% dan quarry Aemau sebesar 1,075%,agregat yang lolos nomor 200 (0,075 mm) quarry Nangapanda sebesar 0,283% dan quarry Aemau sebesar 0,423%, keausan agregat quarry Nangapanda sebesar 18,30% dan quarry Aemau sebesar 12,06%. Hasil akhir agregat dua quarry ini sudah memenuhi syarat SNI dengan perbandingan karakteristik agregat quarry Aemau lebih baik dari agregat quarry Nangapanda

    Efficiently Enumerating Hitting Sets of Hypergraphs Arising in Data Profiling

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    We devise an enumeration method for inclusion-wise minimal hitting sets in hypergraphs. It has delay O(mk* +1 · n2) and uses linear space. Hereby, n is the number of vertices, m the number of hyperedges, and k* the rank of the transversal hypergraph. In particular, on classes of hypergraphs for which the cardinality k* of the largest minimal hitting set is bounded, the delay is polynomial. The algorithm solves the extension problem for minimal hitting sets as a subroutine. We show that the extension problem is W[3]-complete when parameterised by the cardinality of the set which is to be extended. For the subroutine, we give an algorithm that is optimal under the exponential time hypothesis. Despite these lower bounds, we provide empirical evidence showing that the enumeration outperforms the theoretical worst-case guarantee on hypergraphs arising in the profiling of relational databases, namely, in the detection of unique column combinations

    Robotic Arm Exhibit

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    Museums like the Children’s Museums and Theatre of Maine (CMTM) and the EcoTarium continually strive to produce engaging exhibits that promote family learning since families with young children are their primary audiences. Using design criteria developed by museum researchers over recent decades, we built a prototype pneumatic arm exhibit for CMTM to inspire children’s interests in engineering and science. We conducted several rounds of prototyping at the EcoTarium to refine the design. We conclude that the final design was very successful in meeting CMTM’s learning outcomes, including the promotion of family learning and active prolonged engagement, and recommend that the museum move to final fabrication of the exhibit

    Problems with Current Dental Documentation in Germany

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    Background: dental documentation is essential for the representation and communication of dental information amongst researchers and practitioners. Dental documentation has to provide the respective means for (a) the representation of the patient status’ and (b) the possible actions. Methods: the consistency of German definitions currently used for dental findings is evaluated by projecting well known examples onto problem axes like “existence of a structure” and “condition of a structure”. Results: it can be shown that current German dental terminology does not support an unambiguous documentation for any situation in dental practice. In some cases, Multiple aspects are merged in several finding statements and make a stringent derivation of the treatment planning difficult. Conclusions: dental documentation in Germany can in some aspects be improved with respect to (a) precision, (b) expressiveness, (c) simplicity and (d) reproducibility. The main axes of dental documentation are enumerated in preparation of a future top-down approach. Clinical Implications: an optimised finding scheme can enhance the communication amongst researchers and practitioners and thus is supposed to improve the treatment quality in the long run

    Adhesive mechanisms governing interferon-producing cell recruitment into lymph nodes

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    Natural interferon-producing cells (IPCs) are found in peripheral lymph nodes (PLNs), where they support NK cell, T cell, and B cell responses to pathogens. However, their route of entry and the adhesive mechanisms used to gain access to PLNs remain poorly defined. We report that IPCs can enter PLNs via a hematogenous route, which involves a multistep adhesive process, and that transmigration is enhanced by inflammation. Results indicate that L-selectin on IPCs is required for efficient attachment and rolling on high endothelial venules in vivo in both nonstimulated and inflamed PLNs. IPCs, however, also possess functional ligands for E-selectin that contribute to this process only in the latter case. In conjunction with selectin-mediated adhesion, both β1- and β2-integrins participate in IPC attachment to the inflamed vessel wall, whereas chemotaxis relies in part on the chemokine receptor CCR5. Identification of the adhesive machinery required for IPC trafficking into PLNs may provide opportunities to regulate immune responses reliant on the activity of these cells

    Analytic continuation of Taylor series and the two-point boundary value problems of some nonlinear ordinary differential equations

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    We compare and discuss the respective efficiency of three methods (with two variants for each of them), based respectively on Taylor (Maclaurin) series, Pad\'{e} approximants and conformal mappings, for solving quasi-analytically a two-point boundary value problem of a nonlinear ordinary differential equation (ODE). Six configurations of ODE and boundary conditions are successively considered according to the increasing difficulties that they present. After having indicated that the Taylor series method almost always requires the recourse to analytical continuation procedures to be efficient, we use the complementarity of the two remaining methods (Pad\'{e} and conformal mapping) to illustrate their respective advantages and limitations. We emphasize the importance of the existence of solutions with movable singularities for the efficiency of the methods, particularly for the so-called Pad\'{e}-Hankel method. (We show that this latter method is equivalent to pushing a movable pole to infinity.) For each configuration, we determine the singularity distribution (in the complex plane of the independent variable) of the solution sought and show how this distribution controls the efficiency of the two methods. In general the method based on Pad\'{e} approximants is easy to use and robust but may be awkward in some circumstances whereas the conformal mapping method is a very fine method which should be used when high accuracy is required.Comment: Final versio

    The RING-CH ligase K5 antagonizes restriction of KSHV and HIV-1 particle release by mediating ubiquitin-dependent endosomal degradation of tetherin

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    Tetherin (CD317/BST2) is an interferon-induced membrane protein that inhibits the release of diverse enveloped viral particles. Several mammalian viruses have evolved countermeasures that inactivate tetherin, with the prototype being the HIV-1 Vpu protein. Here we show that the human herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) is sensitive to tetherin restriction and its activity is counteracted by the KSHV encoded RING-CH E3 ubiquitin ligase K5. Tetherin expression in KSHV-infected cells inhibits viral particle release, as does depletion of K5 protein using RNA interference. K5 induces a species-specific downregulation of human tetherin from the cell surface followed by its endosomal degradation. We show that K5 targets a single lysine (K18) in the cytoplasmic tail of tetherin for ubiquitination, leading to relocalization of tetherin to CD63-positive endosomal compartments. Tetherin degradation is dependent on ESCRT-mediated endosomal sorting, but does not require a tyrosine-based sorting signal in the tetherin cytoplasmic tail. Importantly, we also show that the ability of K5 to substitute for Vpu in HIV-1 release is entirely dependent on K18 and the RING-CH domain of K5. By contrast, while Vpu induces ubiquitination of tetherin cytoplasmic tail lysine residues, mutation of these positions has no effect on its antagonism of tetherin function, and residual tetherin is associated with the trans-Golgi network (TGN) in Vpu-expressing cells. Taken together our results demonstrate that K5 is a mechanistically distinct viral countermeasure to tetherin-mediated restriction, and that herpesvirus particle release is sensitive to this mode of antiviral inhibition

    P-TEFb Activation by RBM7 Shapes a Pro-survival Transcriptional Response to Genotoxic Stress

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    DNA damage response (DDR) involves dramatic transcriptional alterations, the mechanisms of which remain ill defined. Here, we show that following genotoxic stress, the RNA-binding motif protein 7 (RBM7) stimulates RNA polymerase II (Pol II) transcription and promotes cell viability by activating the positive transcription elongation factor b (P-TEFb) via its release from the inhibitory 7SK small nuclear ribonucleoprotein (7SK snRNP). This is mediated by activation of p38MAPK, which triggers enhanced binding of RBM7 with core subunits of 7SK snRNP. In turn, P-TEFb relocates to chromatin to induce transcription of short units, including key DDR genes and multiple classes of non-coding RNAs. Critically, interfering with the axis of RBM7 and P-TEFb provokes cellular hypersensitivity to DNA-damage-inducing agents due to activation of apoptosis. Our work uncovers the importance of stress-dependent stimulation of Pol II pause release, which enables a pro-survival transcriptional response that is crucial for cell fate upon genotoxic insult.Peer reviewe
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