Expression of a beta 1-related integrin by oligodendroglia in primary culture: evidence for a functional role in myelination.

We have investigated the expression of integrins by rat oligodendroglia grown in primary culture and the functional role of these proteins in myelinogenesis. Immunochemical analysis, using antibodies to a number of alpha and beta integrin subunits, revealed that oligodendrocytes express only one detectable integrin receptor complex (alpha OL beta OL). This complex is immunoprecipitated by a polyclonal anti-human beta 1 integrin subunit antibody. In contrast, astrocytes, the other major glial cell type in brain, express multiple integrins including alpha 1 beta 1, alpha 3 beta 1, and alpha 5 beta 1 complexes that are immunologically and electrophoretically indistinguishable from integrins expressed by rat fibroblasts. The beta subunit of the oligodendrocyte integrin (beta OL) and rat fibroblast beta 1 have different electrophoretic mobilities in SDS-PAGE. However, the two beta subunits appear to be highly related based on immunological cross-reactivity and one-dimensional peptide mapping. After removal of N-linked carbohydrate chains, beta OL and beta 1 comigrated in SDS-PAGE and peptide maps of the two deglycosylated subunits were identical, suggesting differential glycosylation of beta 1 and beta OL accounts entirely for their size differences. The oligodendrocyte alpha subunit, alpha OL, was not immunoprecipitated by antibodies against well characterized alpha chains which are known to associate with beta 1 (alpha 3, alpha 4, and alpha 5). However, an antibody to alpha 8, a more recently identified integrin subunit, did precipitate two integrin subunits with electrophoretic mobilities in SDS-PAGE identical to alpha OL and beta OL. Functional studies indicated that disruption of oligodendrocyte adhesion to a glial-derived matrix by an RGD-containing synthetic peptide resulted in a substantial decrease in the level of mRNAs for several myelin components including myelin basic protein (MBP), proteolipid protein (PLP), and cyclic nucleotide phosphodiesterase (CNP). These results suggest that integrin-mediated adhesion of oligodendrocytes may trigger signal(s) that induce the expression of myelin genes and thus influence oligodendrocyte differentiation

Comment on "Competition between helimagnetism and commensurate quantum spin correlations in LiCu2O2"

The microscopic origin of the recently observed helical structure in LiCu2O2 [1] is considered. It is shown that the frustrated antiferromagnetic double chain scenario adopted in Ref.1 is unrealistic. It should be replaced by a frustrated single-chain (CuO2) scenario proposed in Ref. 2 with ferromagnetic nearest neighbor and antiferromagnetic next nearest neighbor exchange integrals \. [1] T. Masuda et al. Phys. Rev. Lett. 92 (2004), 177201. [2] A. Gippius et al. Phys. Rev. B 70 (2004), R01426; cond-mat/0312576.Comment: one page, one figur

Identifications and SEDs of the detected sources from the AKARI Deep Field South

In order to find counterparts of the detected objects in the AKARI Deep Field South (ADFS) in all available wavelengths, we searched public databases (NED, SIMBAD and others). Checking 500 sources brighter than 0.0482 Jy in the AKARI Wide-S band, we found 114 sources with possible counterparts, among which 78 were known galaxies. We present these sources as well as our first attempt to construct spectral energy distributions (SEDs) for the most secure and most interesting sources among them, taking into account all the known data together with the AKARI measurements in four bands.Comment: 4 pages, 10 figures, To appear in: the proceedings of the conference "AKARI, a light to illuminate the misty Universe", February 16-19 2009, Toky

Cabaran dan Strategi Menghadapi Perubahan Kurikulum dalam Kalangan Pensyarah Bidang Agroteknologi Kolej Komuniti : Challenges and Strategies in Curriculum Change among Agrotechnology Lecturers in Community College

Isu perubahan iklim, kekurangan sumber, kemajuan kecerdasan buatan, ledakan teknologi dan globalisasi memberi impak kepada pasaran buruh dalam bidang pertanian. Hal ini menyebabkan institusi Pendidikan Latihan Teknikal dan Vokasional (PLTV) menghadapi tekanan untuk menyediakan graduan berkemahiran tinggi seiring dengan matlamatnya. Oleh itu, bagi mengatasi masalah ini PLTV terutamanya Kolej Komuniti terdesak untuk melakukan perubahan terhadap kurikulum Program Sijil Kolej Komuniti (SKK) terutamanya dalam bidang agroteknologi. Oleh itu kajian ini adalah bertujuan untuk meneroka cabaran dan strategi pensyarah bidang agroteknologi di Kolej Komuniti dalam menghadapi perubahan kurikulum. Kajian ini dijalankan menggunakan pendekatan kualitatif dengan reka bentuk kajian tinjauan. Pengumpulan data kajian dilaksanakan melalui temu bual separa berstruktur dengan menggunakan protokol temu bual yang diadaptasi daripada kajian-kajian lepas. Populasi kajian terdiri daripada pensyarah bidang agroteknologi di Kolej Komuniti dan kaedah persampelan bertujuan digunakan untuk memilih enam orang responden kajian. Data yang diperoleh dianalisis secara tematik. Penemuan kajian mendapati pensyarah menghadapi cabaran dari aspek kepakaran, pengetahuan dan kompetensi; kekangan masa; kekurangan sumber; dan reka bentuk kurikulum. Pensyarah juga mengesyorkan strategi menghadapi cabaran perubahan kurikulum dari aspek latihan; penambahbaikan sumber; penambahbaikan kurikulum; dan jaminan kualiti. Dapatan kajian ini dijangka memberi sumbangan dalam merangka proses perubahan kurikulum terutamanya bagi Program SKK bidang agroteknologi dengan teliti, sistematik dan berkesan.   Climate change, shortages of resources, advancements in artificial intelligence, technological explosions, and globalization have an impact on the agricultural labour market. As a result, the Institute of Technical and Vocational Training Education (PLTV) is under pressure to produce highly trained graduates in order to meet its objectives. In an effort to resolve this issue, PLTV, particularly Community College, is urgently needed to revise the curriculum of the Community College Certificate Programme (SKK), particularly in the field of agrotechnology. The study aims at exploring the challenges and strategies of agrotechnology lecturers at Community College in facing the prospect of curriculum changes. The survey study was designed implementing a qualitative methodology. The collection of survey data is carried out through semi-structured interviews using adapted interview protocols. The study population consisted of lecturers in the field of agrotechnology at Community College covering three clusters namely agriculture technology, aquaculture and food processing and quality control. The purposive sampling method is used to select six survey informan who meet the set criteria. The data obtained is analyzed thematically. The findings of the study find lecturers facing challenges from aspects of expertise, knowledge, and competence; time constraints; lack of resources; and curriculum design. The lecturers also recommended strategies to overcome the challenges in curriculum change from the practice aspect; resource improvement; curricular improvements; and quality assurance. This finding is expected to contribute to the the curriculum change process especially for the Agrotechnology Certificate Program

Intrinsic localized modes in the charge-transfer solid PtCl

We report a theoretical analysis of intrinsic localized modes in a quasi-one-dimensional charge-transfer-solid $[Pt(en)_2][Pt(en)_2 Cl_2](ClO_4)_4$(PtCl). We discuss strongly nonlinear features of resonant Raman overtone scattering measurements on PtCl, arising from quantum intrinsic localized (multiphonon) modes (ILMs) and ILM-plus-phonon states. We show, that Raman scattering data displays clear signs of a non-thermalization of lattice degrees-of-freedom, manifested in a nonequilibrium density of intrinsic localized modes.Comment: 4 pages, 4 figures, REVTE

Knudsen gas in a finite random tube: transport diffusion and first passage properties

We consider transport diffusion in a stochastic billiard in a random tube which is elongated in the direction of the first coordinate (the tube axis). Inside the random tube, which is stationary and ergodic, non-interacting particles move straight with constant speed. Upon hitting the tube walls, they are reflected randomly, according to the cosine law: the density of the outgoing direction is proportional to the cosine of the angle between this direction and the normal vector. Steady state transport is studied by introducing an open tube segment as follows: We cut out a large finite segment of the tube with segment boundaries perpendicular to the tube axis. Particles which leave this piece through the segment boundaries disappear from the system. Through stationary injection of particles at one boundary of the segment a steady state with non-vanishing stationary particle current is maintained. We prove (i) that in the thermodynamic limit of an infinite open piece the coarse-grained density profile inside the segment is linear, and (ii) that the transport diffusion coefficient obtained from the ratio of stationary current and effective boundary density gradient equals the diffusion coefficient of a tagged particle in an infinite tube. Thus we prove Fick's law and equality of transport diffusion and self-diffusion coefficients for quite generic rough (random) tubes. We also study some properties of the crossing time and compute the Milne extrapolation length in dependence on the shape of the random tube.Comment: 51 pages, 3 figure