717 research outputs found

    Characterization of Aquaporin 4 Protein Expression and Localization in Tissues of the Dogfish (Squalus acanthias)

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    The role of aquaporin water channels such as aquaporin 4 (Aqp4) in elasmobranchs such as the dogfish Squalus acanthias is completely unknown. This investigation set out to determine the expression and cellular and sub-cellular localization of Aqp4 protein in dogfish tissues. Two polyclonal antibodies were generated (AQP4/1 and AQP4/2) and these showed somewhat different characteristics in Western blotting and immunohistochemistry. Western blots using the AQP4/1 antibody showed two bands (35.5 and 49.5 kDa) in most tissues in a similar fashion to mammals. Liver had an additional band of 57 kDa and rectal gland two further faint bands of 37.5 and 38.5 kDa. However, unlike in mammals, Aqp4 protein was ubiquitously expressed in all tissues including gill and liver. The AQP4/2 antibody appeared much less specific in Western blots. Both antibodies were used in immunohistochemistry and showed similar cellular localizations, although the AQP4/2 antibody had a more restricted sub-cellular distribution compared to AQP4/1 and therefore appeared to be more specific for Aqp4. In kidney a sub-set of tubules were stained which may represent intermediate tubule segments (In-III–In-VI). AQP4/1 and AQP4/2 antibodies localized to the same tubules segments in serial sections although the intensity and sub-cellular distribution were different. AQP4/2 showed a basal or basolateral membrane distribution whereas AQP4/1 was often distributed throughout the whole cell including the nuclear region. In rectal gland and cardiac stomach Aqp4 was localized to secretory tubules but again AQP/1 and AQP/2 exhibited different sub-cellular distributions. In gill, both antibodies stained large cells in the primary filament and secondary lamellae. Again AQP4/1 antibody stained most or all the cell including the nucleus, whereas AQP4/2 had a plasma membrane or plasma membrane and cytoplasmic distribution. Two types of large mitochondrial rich transport cells are known to exist in elasmobranchs, that express either Na, K-ATPase, or V-type ATPase ion transporters. Using Na, K-ATPase, and V-type ATPase antibodies, Aqp4 was colocalized with these proteins using the AQP4/1 antibody. Results show Aqp4 is expressed in both (and all) branchial Na, K-ATPase, and V-type ATPase expressing cells

    Characterization of Aquaporin 4 Protein Expression and Localization in Tissues of the Dogfish (\u3cem\u3eSqualus acanthias\u3c/em\u3e)

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    The role of aquaporin water channels such as aquaporin 4 (Aqp4) in elasmobranchs such as the dogfish Squalus acanthias is completely unknown. This investigation set out to determine the expression and cellular and sub-cellular localization of Aqp4 protein in dogfish tissues. Two polyclonal antibodies were generated (AQP4/1 and AQP4/2) and these showed somewhat different characteristics in Western blotting and immunohistochemistry. Western blots using the AQP4/1 antibody showed two bands (35.5 and 49.5 kDa) in most tissues in a similar fashion to mammals. Liver had an additional band of 57 kDa and rectal gland two further faint bands of 37.5 and 38.5 kDa. However, unlike in mammals, Aqp4 protein was ubiquitously expressed in all tissues including gill and liver. The AQP4/2 antibody appeared much less specific in Western blots. Both antibodies were used in immunohistochemistry and showed similar cellular localizations, although the AQP4/2 antibody had a more restricted sub-cellular distribution compared to AQP4/1 and therefore appeared to be more specific for Aqp4. In kidney a sub-set of tubules were stained which may represent intermediate tubule segments (In-III–In-VI). AQP4/1 and AQP4/2 antibodies localized to the same tubules segments in serial sections although the intensity and sub-cellular distribution were different. AQP4/2 showed a basal or basolateral membrane distribution whereas AQP4/1 was often distributed throughout the whole cell including the nuclear region. In rectal gland and cardiac stomach Aqp4 was localized to secretory tubules but again AQP/1 and AQP/2 exhibited different sub-cellular distributions. In gill, both antibodies stained large cells in the primary filament and secondary lamellae. Again AQP4/1 antibody stained most or all the cell including the nucleus, whereas AQP4/2 had a plasma membrane or plasma membrane and cytoplasmic distribution. Two types of large mitochondrial rich transport cells are known to exist in elasmobranchs, that express either Na, K-ATPase, or V-type ATPase ion transporters. Using Na, K-ATPase, and V-type ATPase antibodies, Aqp4 was colocalized with these proteins using the AQP4/1 antibody. Results show Aqp4 is expressed in both (and all) branchial Na, K-ATPase, and V-type ATPase expressing cells

    Nuclear reactor power as applied to a space-based radar mission

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    The SP-100 Project was established to develop and demonstrate feasibility of a space reactor power system (SRPS) at power levels of 10's of kilowatts to a megawatt. To help determine systems requirements for the SRPS, a mission and spacecraft were examined which utilize this power system for a space-based radar to observe moving objects. Aspects of the mission and spacecraft bearing on the power system were the primary objectives of this study; performance of the radar itself was not within the scope. The study was carried out by the Systems Design Audit Team of the SP-100 Project

    Karakteristik Silase Semak Bunga Putih (Chromolaena odorata) dengan Penambahan Jenis Karbohidrat Terlarut yang Berbeda

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    Penelitian bertujuan untuk mengetahui karakteristik silase semak bunga putih (Chromolaena odorata) yang ditambahkan jenis karbohdirat terlarut yang berbeda. Penelitian menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 4 ulangan. Perlakuan terdiri dari R0 : Semak bunga putih (70%) + Lamtoro (30%) (kontrol), R1 : Semak bunga putih (70%) + Lamtoro (20%) + Dedak Padi (10%), R2 : Semak bunga putih (70%) + Lamtoro (20%) + Tepung Gaplek (10%), R3 : Semak bunga putih (70%) + Lamtoro (20%) + Tepung Jagung (10%), Persentase dedak padi, tepung jagung dan tepung gaplek dihitung berdasarkan berat cacahan daun SBP dan lamtoro dalam kondisi layu. Variabel yang diteliti adalah karakteristik fisik (organoleptik) dan kimia (proksimat) silase semak bunga putih. Hasil penelitian menunjukkan penambahan karbohidrat terlarut berpengaruh nyata terhadap karaktersitik fisik dan kimia silase. Disimpulkan bahwa penambahan tepung gaplek berpengaruh dan nyata lebih tinggi dalam menghasilkan karakteristik fisik silase semak bunga putih yang terbaik. sedangkan karakteristik kimia, penambahan dedak padi sebagai karbohidrat terlarut nyata lebih tinggi dibandingkan dengan tepung gaplek dan tepung jagung.

    Neutron diffraction reveals sequence-specific membrane insertion of pre-fibrillar islet amyloid polypeptide and inhibition by rifampicin

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    AbstractHuman islet amyloid polypeptide (hIAPP) forms amyloid deposits in non-insulin-dependent diabetes mellitus (NIDDM). Pre-fibrillar hIAPP oligomers (in contrast to monomeric IAPP or mature fibrils) increase membrane permeability, suggesting an important role in the disease. In the first structural study of membrane-associated hIAPP, lamellar neutron diffraction shows that oligomeric hIAPP inserts into phospholipid bilayers, and extends across the membrane. Rifampicin, which inhibits hIAPP-induced membrane permeabilisation in functional studies, prevents membrane insertion. In contrast, rat IAPP (84% identical to hIAPP, but non-amyloidogenic) does not insert into bilayers. Our findings are consistent with the hypothesis that membrane-active pre-fibrillar hIAPP oligomers insert into beta cell membranes in NIDDM

    3-(2,4-Dichloro­phen­yl)-1,5-di-2-furylpentane-1,5-dione

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    In the title compound, C19H14Cl2O4, intra­molecular C—H⋯O and C—H⋯Cl hydrogen bonds generate S(6) and S(5) ring motifs, respectively. In the crystal structure, inter­molecular C—H⋯O inter­actions between symmetry-related mol­ecules involving two methyl­ene groups and an O atom as a bifurcated acceptor generate an R 2 1(6) ring motif. In the mol­ecule, one of the furan rings is rotationally disordered by approximately 180° about the single C—C bond to which it is attached; the refined site-occupancy factors are 0.505 (7) and 0.495 (7). The major component of the disordered furan ring and the benzene ring form a dihedral angle of 88.8 (4)°. The dihedral angle between the major disorder component and the other furan ring is 81.9 (4)°. In addition, the crystal structure is stabilized by further inter­molecular C—H⋯O (×2) hydrogen bonds and C—H⋯π inter­actions

    Estimating cortical thickness trajectories in children across different scanners using transfer learning from normative models

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    This work illustrates the use of normative models in a longitudinal neuroimaging study of children aged 6–17 years and demonstrates how such models can be used to make meaningful comparisons in longitudinal studies, even when individuals are scanned with different scanners across successive study waves. More specifically, we first estimated a large-scale reference normative model using Hierarchical Bayesian Regression from N = 42,993 individuals across the lifespan and from dozens of sites. We then transfer these models to a longitudinal developmental cohort (N = 6285) with three measurement waves acquired on two different scanners that were unseen during estimation of the reference models. We show that the use of normative models provides individual deviation scores that are independent of scanner effects and efficiently accommodate inter-site variations. Moreover, we provide empirical evidence to guide the optimization of sample size for the transfer of prior knowledge about the distribution of regional cortical thicknesses. We show that a transfer set containing as few as 25 samples per site can lead to good performance metrics on the test set. Finally, we demonstrate the clinical utility of this approach by showing that deviation scores obtained from the transferred normative models are able to detect and chart morphological heterogeneity in individuals born preterm.</p

    Estimating cortical thickness trajectories in children across different scanners using transfer learning from normative models

    Get PDF
    This work illustrates the use of normative models in a longitudinal neuroimaging study of children aged 6–17 years and demonstrates how such models can be used to make meaningful comparisons in longitudinal studies, even when individuals are scanned with different scanners across successive study waves. More specifically, we first estimated a large-scale reference normative model using Hierarchical Bayesian Regression from N = 42,993 individuals across the lifespan and from dozens of sites. We then transfer these models to a longitudinal developmental cohort (N = 6285) with three measurement waves acquired on two different scanners that were unseen during estimation of the reference models. We show that the use of normative models provides individual deviation scores that are independent of scanner effects and efficiently accommodate inter-site variations. Moreover, we provide empirical evidence to guide the optimization of sample size for the transfer of prior knowledge about the distribution of regional cortical thicknesses. We show that a transfer set containing as few as 25 samples per site can lead to good performance metrics on the test set. Finally, we demonstrate the clinical utility of this approach by showing that deviation scores obtained from the transferred normative models are able to detect and chart morphological heterogeneity in individuals born preterm.</p

    3-Hydr­oxy-4-methoxy­benzaldehyde thio­semicarbazone hemihydrate

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    The asymmetric unit of the title compound, C9H11N3O2S·0.5H2O, comprises two crystallograpically independent thio­semicarbazone mol­ecules (A and B) and a water mol­ecule of crystallization. In each of the thio­semicarbazone mol­ecules, intra­molecular O—H⋯O and N—H⋯N hydrogen bonds form five-membered rings, producing S(5) ring motifs. Inter­molecular O—H⋯S and N—H⋯O inter­actions between mol­ecule B and the water mol­ecule form a six-membered ring, producing an R 2 2(6) ring motif. Inter­molecular N—H⋯S hydrogen bonds form dimers involving pairs of both A and B mol­ecules, which form R 2 2(8) ring motifs. The angles between the aromatic ring and thio­urea unit in the two mol­ecules are 0.80 (6) and 3.28 (5)°, which proves that each mol­ecule is fairly planar. The crystal structure is stabilized by inter­molecular O—H⋯S (×2), O—H⋯O, N—H⋯S (×2) and N—H⋯O (×2) hydrogen bonds and C—H⋯O (×2) contacts to form a three-dimensional network
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