1,461 research outputs found
The Variance of QSO Counts in Cells
{}From three quasar samples with a total of 1038 objects in the redshift
range we measure the variance of counts in cells of
volume . By a maximum likelihood analysis applied separately on these
samples we obtain estimates of , with .
The analysis from a single catalog for Mpc and from a
suitable average over the three catalogs for and
Mpc, gives , ,
and , respectively, where the
confidence ranges account for both sampling errors and statistical
fluctuations in the counts. This allows a comparison of QSO clustering on large
scales with analogous data recently obtained both for optical and IRAS
galaxies: QSOs seem to be more clustered than these galaxies by a biasing
factor .Comment: 13 pages in plain Tex, 5 figures available in postscript in a
separate file, submitted to ApJ, DAPD-33
Band structure and optical properties of opal photonic crystals
A theoretical approach for the interpretation of reflectance spectra of opal
photonic crystals with fcc structure and (111) surface orientation is
presented. It is based on the calculation of photonic bands and density of
states corresponding to a specified angle of incidence in air. The results
yield a clear distinction between diffraction in the direction of light
propagation by (111) family planes (leading to the formation of a stop band)
and diffraction in other directions by higher-order planes (corresponding to
the excitation of photonic modes in the crystal). Reflectance measurements on
artificial opals made of self-assembled polystyrene spheres are analyzed
according to the theoretical scheme and give evidence of diffraction by
higher-order crystalline planes in the photonic structure.Comment: to appear in PR
Pengaruh Kualitas Produk dan Kualitas Pelayanan terhadap Minat Beli Ulang Pelanggan Shao Kao Kertajaya melalui Kepuasan Pelanggan
Penelitian ini bertujuan untuk mengetahui pengaruh dari kualitas produk dan kualitas pelayanan terhadap minat beli ulang dengan kepuasan pelanggan sebagai mediator. Penelitian menggunakan 150 responden yang merupakan pelanggan Shao Kao. Data yang diperoleh diolah menggunakan metode Partial Least Square. Hasil penelitian menunjukkan bahwa kualitas produk dan pelayanan keduanya berpengaruh signifikan terhadap kepuasan pelanggan dan kepuasan pelanggan sendiri berpengaruh signifikan positif terhadap minat beli ulang. Dalam penelitian ini pengaruh tidak langsung yang terbentuk bersifat memperlemah
Analisa Pengaruh Customer Experience Terhadap Minat Beli Konsumen Di Sushi Tei Restaurant Surabaya
Penelitian ini dilakukan untuk mengetahui customer experience yang terdiri dari sensory experience, emotional experience, dan social experience terhadap minat beli konsumen di Sushi Tei Restaurant Surabaya. Peneliti mengambil sampel sebanyak 70 responden. Berdasarkan hasil analisa, disimpulkan bahwa sensory experience dan social experience berpengaruh terhadap minat beli konsumen, sedangkan emotional experience tidak berpengaruh terhadap minat beli konsumen. Dari hasil analisa tersebut juga disimpulkan bahwa variabel yang paling dominan adalah social experience
Analisa Pengembangan Strategi Emotional Branding Dalam Membangun Loyalitas Konsumen Garuda Indonesia Airlines
Penelitian ini bertujuan untuk mengetahui perkembangan strategi dari emotional branding terhadap loyalitas konsumen Garuda Indonesia di Jakarta, Surabaya, dan Bali berdasarkan empat konsep dasar emotional branding menurut Gobe yaitu hubungan, pengalaman pancaindera, imajinasi, dan visi. Penelitian ini menggunakan metode kuantitatif dan pemilihan subyek dilakukan menggunakan teknik purposive sampling. Responden dalam penelitian ini adalah konsumen loyal Garuda Indonesia yang telah menggunakan layanan jasa Garuda Indonesia dalam satu tahun terakhir sebanyak minimal dua kali.Metode penelitian survei dengan menggunakan analisa regresi linear berganda digunakan dalam penelitian ini. Hasil penelitian ini menunjukkan pengalaman pancaindera, imajinasi, dan visi berpengaruh secara signifikan terhadap loyalitas konsumen sedangkan hubungan berpengaruh secara tidak signifikan terhadap loyalitas konsumen
Human leucocyte antigen diversity: a biological gift to escape infections, no longer a barrier for haploidentical hemopoietic stem cell transplantation
Since the beginning of life, every multicellular organism appeared to have a complex innate immune system although the adaptive immune system, centred on lymphocytes bearing antigen receptors generated by somatic recombination, arose in jawed fish approximately 500 million years ago. The major histocompatibility complex MHC, named the Human leucocyte antigen (HLA) system in humans, represents a vital function structure in the organism by presenting pathogen-derived peptides to T cells as the main initial step of the adaptive immune response. The huge level of polymorphism observed in HLA genes definitely reflects selection, favouring heterozygosity at the individual or population level, in a pathogen-rich environment, although many are located in introns or in exons that do not code for the antigen-biding site of the HLA. Over the past three decades, the extent of allelic diversity at HLA loci has been well characterized using high-resolution HLA-DNA typing and the number of new HLA alleles, produced through next-generation sequencing methods, is even more rapidly increasing. The level of the HLA system polymorphism represents an obstacle to the search of potential compatible donors for patients affected by haematological disease proposed for a hematopoietic stem cell transplant (HSCT). Data reported in literature clearly show that antigenic and/or allelic mismatches between related or unrelated donors and patients influences the successful HSCT outcome. However, the recent development of the new transplant strategy based on the choice of haploidentical donors for HSCT is questioning the role of HLA compatibility, since the great HLA disparities present do not worsen the overall clinical outcome. Nowadays, NGS has contributed to define at allelic levels the HLA polymorphism and solve potential ambiguities. However, HLA functions and tissue typing probably need to be further investigated in the next future, to understand the reasons why in haploidentical transplants the presence of a whole mismatch haplotype between donors and recipients, both the survival rate and the incidence of acute GvHD or graft rejection are similar to those reported for unrelated HSCTs
Preparation and Comparison of Hydrolase-Coated Plastics
Polypropylene and polyethylene were coated with alpha-Chymotrypsin
(a-CT) or subtilisin Carlsberg (SubC) or Burkholderia
cepacia lipase (lipase BC) by different immobilization procedures,
such as physical adsorption and covalent linking. This
latter procedure was based on the chemical functionalization
of the plastic surface by oxygen gas plasma treatment. Immobilization
of the enzyme was carried out by using as cross-linking
agent i) glutaraldehyde (GA) or ii) N’-diisopropylcarbodiimide
(DIC) and N-hydroxysuccinimide (NHS). The effects of duration
of the plasma treatment and the type of the immobilization
procedure on the transesterification activity of the enzyme
were investigated. In general polypropylene resulted a better
support than polyethylene. Moreover, a-CT showed higher
transesterification activity when immobilized with GA, while for
SubC, DIC and NHS were better cross-linking agents than GA.
No activity was observed with these enzymes when immobilization
was carried out by physical adsorption. On the contrary,
lipase BC immobilized by physical adsorption was even more
active than the free enzyme. Concerning thermal stability, immobilized
SubC was less stable than the free enzyme. Overall,
these results show that plastics endowed with biocatalytic
properties could be obtained by simple immobilization protocols
and that optimal immobilization conditions depend on the
type of starting plastic, plasma treatment, cross-linking method,
and the nature of the enzyme
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