624 research outputs found
Biorthogonal wavelet theory and techniques for image coding
No full textThis paper concentrates on two issues related to wavelet-based image coding. At first, an algebra method is proposed to select biorthogonal wavelets for higher compression ratio and better quality of the reconstructed image. Then, a general algorithm is given to convert a discrete biorthogonal wavelet transform into lifting steps, so that one version of the transform, which maps integers to integers, can support both the lossy and lossless coding to facilitate the region of interest based image compression.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000077172800005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Software EngineeringCPCI-S(ISTP)
Finite-dimensional integrable systems related to the n-wave interaction equations
No full textUnder a constraint between the potentials and the eigenfunctions, Lax pairs and adjoint Lax pairs of a soliton hierarchy associated with the nxn generalized Zakharov-Shabat eigenvalue problem are transformed into a spatial finite-dimensional Hamiltonian system and a hierarchy of temporal finite-dimensional Hamiltonian systems. The Lax representations, r-matrix structure and integrals of motion are explicitly presented. These integrals of motion are functionally independent and in involution in pairs, which shows that these systems, especially the whole hierarchy of temporal finite-dimensional Hamiltonian systems, are Liouville integrable. (C) 2001 American Institute of Physics.Physics, MathematicalSCI(E)0ARTICLE83554-35644
Efficacy and safety of different doses of a slow-release corticosteroid implant for macular edema [Corrigendum]
No full textLiu QY, He MM, Shi H, et al. Drug Des Devel Ther. 2015;9: 2527–2535. In “Efficacy and safety of different doses of a slow release corticosteroid implant for macular edema: meta-analysis of randomized controlled trials” published May 2015, on page 2530, in Table 1 we have mistakenly stated the fluocinolone acetonide (FA) intravitreal inserts as Retisert® in the Campochiaro et al study; they were in fact the fluocinolone acetonide intravitreal inserts. We feel sorry about that, and we will be more rigorous to avoid any unnecessary confusion in the future. Read the original articl
A review of environment problems in the coastal sea of South China
No full textThe coastal sea of South China provided an important habitat for protection and propagation of marine organisms. Rapid economic development and human activities, such as wastewater discharge, reclamation, overfishing and aquaculture in the South China Sea had already resulted in environmental degradation, and thus caused sharp contradictions between exploitation and protection of the coastal sea of South China. In this present article, the main environment problems and degradation trends were reviewed based on literatures and other sources of information, which mainly referenced nutrient pollution, persistent organic pollution and metal pollution, decrease of biodiversity, reduction of marine habitat and frequent natural and ecological disasters. The current efforts in China on protecting the environment in the coastal sea of South China were discussed, which included improving legislation by formulating a series of laws and regulations at national or local level, setting up natural reserves, and supporting research projects. There were many challenges regarding policy, management and science research to protect and sustain the coastal sea of South China, such as imperfect legal and administrative systems, lack of public participation, poor financial support and lack of monitoring and evaluation. Finally, some recommendations were put forward for the sake of the sustainable use of the environment in the coastal sea of South China, including reinforcing the planning of marine resource exploitation and use through integrated coastal zone management, strengthening the marine environment and protection awareness of the public, and scientifically establishing the fishery spawning spots and aquatic reserves
Pseudo-binary systems CsAlF4-KAlF4 and Cs3AlF6-K3AlF6
No full textPhase relations in the system CsAlF4-KAlF4 and Cs3AlF6-K3AlF6 were investigated by DTA and XRD methods. In the system CsAlF4-KAlF4, two intermediate compounds 3CsAlF(4). KAlF4 and CsAlF4. KAlF4 were confirmed. The first one was indexed as orthorhombic with a = 9.079 +/- 0.003, b = 7.958 +/- 0.002, c = 7.648 +/- 0.004 Angstrom. The second one alpha-CsAlF4. KAlF4 is also orthorhombic, a = 10.982 +/- 0.005, b = 10.093 +/- 0.006, c = 6.160 +/- 0.002 Angstrom. Among the two compounds and KAlF4, two eutectic temperatures e(1) and e(2) are formed. The first eutectic temperature e(1) is located in 42 mol % KAlF4 at 525 degrees C, and e(2) in 70 mol % KAlF4 at 510 degrees C. The system Cs3AlF6-K3AlF6 is a successive solid solution system with the lowest melting point, the composition of which is 75 mol % Cs3AlF6 at 775 degrees C. In the solid solution, compound 2Cs(3)AlF(4). K3AlF6 was formed at 656 degrees C, and was indexed as a cubic cell with a = 8.891 Angstrom. (C) 1999 Elsevier Science B.V. All rights reserved.Chemistry, AnalyticalChemistry, PhysicalSCI(E)4ARTICLE1-2135-13933
Morphological, Glycohistochemical, and Immunohistochemical Studies on the Embryonic and Adult Bovine Testis
No full textIn the present study, the testes of 32 bovine embryos with different crown-rump length (2.5-
90 cm CRL) and of 15 sexually mature bulls (Deutsches Fleckvieh) were investigated using
light- and electron microscope as well as glycohistochemical and immunohistochemical
methods. The gestation period was divided into 3 stages; early, mid, and late gestation.
Developmental changes in the testicular morphogenesis were therefore analyzed in details
during these phases.
Generally, embryonic development of bovine testis involves the same mechanism described
in other mammals. At the first stage of this study (2.5 cm CRL/43 dpc), the anlage of the
testes protruded to the coelomic cavity as paired bean-shaped structures on either side of the
dorsal mesentery medial to the mesonephros. It consists of primitive testicular cords,
interstitium, and rete testis blastema. Proceeding with fetal age, these basic testicular
structures are further differentiated. The tunica albuginea is separated into two layers: an outer
fibrous layer (tunica fibrosa) with some mesenchymal cells, numerous fibroblast, and much
fibrous content and an inner cellular layer with several blood vessels (tunica vasculosa). The
testicular cords are surrounded by a marked basal lamina and peritubular cells and lined by
two types of cells: a large number of dark polygonal cells with irregular nuclei, pre-Sertoli
cells and small number of large light round cells with relatively round nuclei, the
prespermatogonia. The average number of the germ cells per cross section of cord increases,
particularly form 3.5 to 14 cm CRL, resulting in a germ cell maximum at the end of this stage
(14 cm CRL). Although most of the germ cells are located toward the periphery of the cord,
some are also found in the center. Pre-Sertoli cells form a complete layer at the periphery of
the cords. Generally, these cells are irregular in shape and numerous but considerably smaller
than the germ cells. Unlike prespermatogonia, mitotic figures are seen in pre-Sertoli cells
during the whole embryonic life. As a consequence of the expansion in the interstitium, the
seminiferous cords are progressively separated from each other. The testicular interstitium is
rapidly differentiated and is composed of several islets or clusters of polygonal Leydig cells,
peritubular flattened cells surrounding the testicular cords, connective tissue cells, and
numerous blood vessels. In the present study, fetal Leydig cells were first recognized at 3.5
cm CRL. Thereafter, the average number of these cells is rapidly increased to attain their maximum with the end of the first gestation period (14 cm CRL). This generation of Leydig
cells however dedifferentiates progressively with developmental age. A continuous system of
basal lamina joins the testicular cords with rete strands from 10 cm CRL and onwards. This
system establishes the first connection between these two testicular components via ill-developed uncanalized straight tubules (tubuli recti). Rete testis channels are lined by simple
layer of cuboidal epithelium with round nuclei occupying most of the cytoplasm and enclosed
by well-defined basal lamina.
The adult bovine testis is enclosed by a connective tissue capsule, tunica albuginea, composed
predominantly of collagen fibers and few elastic fibers. Most of the testicular parenchyma is
made up of the convoluted seminiferous tubules (tubuli seminiferi contorti), two-ended
convoluted loops, with both ends opening into the rete testis via specialized terminal
segments. The seminiferous tubules of sexually mature bulls are enclosed by a distinct lamina
propria and are lined by two cell populations, non-proliferating Sertoli cells and highly
proliferating spermatogenic cells. The bovine lamina propria consists of basal lamina,
collagen and elastic fibers, and 3-5 layers of partially overlapping myofibroblasts.
Additionally, fibrocytes, collagen fibrils, and fibroblasts-like cells form the outermost border
of the tubulus. Sertoli cells are easily identifiable elements of the seminiferous epithelium.
Adult Sertoli cells are large irregularly shaped cells with their broad bases resting on the basal
lamina while the remaining cytoplasmic processes extend upward to the tubular lumen. They
are characterized by round or oval euchromatin-rich nuclei situating in the basal portion near
the basal lamina of the seminiferous tubules. Adult bovine germ cells are present in four
morphologically different groups, i.e., spermatogonia, spermatocytes, spermatids, and
spermatozoa. The seminiferous cycle stages are identified using changes in the germ cell
nuclei as well as location and shape of spermatids. According to this method, eight stages are
defined in the seminiferous epithelium of bovine. The interstitial or intertubular tissue of adult
bovine testis consists of Leydig cells, macrophages, scattered lymphocytes and plasma cells,
and contains numerous blood and lymph vessels. Not all Leydig cells have contact to blood or
lymph capillaries.
The excurrent duct system of the adult bovine testis consists of terminal segment of the
convoluted seminiferous tubules, straight tubules, and rete testis. The terminal segment can be
further subdivided into a proximal (transitional) region, middle portion, and distal part
(terminal plug). The proximal region is lined by typical Sertoli cells while the last two parts
are lined by modified Sertoli cells. The tubulus rectus of adult bovine testis is composed of
three morphologically different regions: a proximal cup-shaped region, a middle narrow stalk,
and a distal festooned portion. The rete testis is a complicated centrally positioned meshwork
of intercommunicating channels that lies within the mediastinum testis parallel to the long
axis of epididymis. The simple cuboidal epithelium of straight tubules and rete testis is shown
to contain some lymphocytes and macrophages.
The cellular distribution of glycoconjugates within the fetal and adult bovine testis was
investigated using thirteen (ConA, PSA, LCA, PNA, GSA-I, ECA, DBA, SBA, HPA, VVA,
WGA, UEA-I, LTA) different fluorescein isothiocyanate (FITC) conjugated lectins. In fetal
testes, detection of sugar moieties by lectins was carried out on Bouin õ s-fixed paraffin-embedded sections while in adult it was performed on both Bouin õ s-fixed paraffin-embedded and acetone-fixed frozen sections. Only five lectins (PSA, PNA, GSA-I, DBA, WGA) showed a positive reaction in the embryonic testes. PNA, GSA-I, DBA, and WGA were detected in the germ cells whereas PSA, DBA and WGA labeled the fetal Leydig cells. None of the lectins used was observed in the pre-Sertoli cells. Further on, some lectins were seen in tunica albuginea (PSA, PNA, GSA-I, WGA), basal lamina of testicular cords (PSA, WGA), interstitial blood vessels (PSA, GSA-I, WGA), mediastinum testis (PSA, PNA, WGA) and rete testis epithelium (PNA). In adult animals, spermatogonia and spermatocytes were positively stained with PSA, LCA, DBA, SBA, and VVA. All the lectins investigated except that of the fucose-binding lectin (UEA-I and LTA) were definitely detected in the acrosome of round and elongated spermatids. These results indicate a role for carbohydrates in spermiogenesis. Apical Sertoli cells processes and Leydig cells were weakly stained with
PSA and LCA as well. DBA binding sites were also seen in the Leydig cells.
Immunohistochemical studies were performed using the Avidin-Biotin-Peroxidase Complex
(ABC) method for localization of fibroblast growth factor-1 (FGF-1), fibroblast growth
factor-2 (FGF-2), S-100, laminin, alpha-smooth muscle actin (á -SMA), vascular endothelial
growth factor (VEGF), connexin 43 (Cx43), CD4, CD8, CD68, angiotensin-converting
enzyme (ACE), and galactosyltransferase (GalTase) in the bovine testis. The expression of
FGF-1 and FGF-2 was further investigated in the adult bovine testis using in situ
hybridization and PCR. Immunohistochemically, FGF-1 was seen in the Sertoli cells, Leydig
cells, endothelium of the blood vessels, and epithelium of straight tubules and rete testis of
fetal and adult testis. It was additionally detected in spermatogonia and spermatids of sexual
mature animals. FGF-2 exhibited a striking positive reaction in fetal (from 6 to 30 cm CRL)
and adult Leydig cells. Moreover, it showed marked reaction in the endothelium of blood
vessels and in the epithelium of tubulus rectus and rete testis. FGF-2 was also localized in
some spermatogonia, and myofibroblasts. By means of in situ hybridization, FGF-1 and FGF-2 mRNA were found in Leydig and Sertoli cells as well as in the modified Sertoli cells of the
terminal segment. FGF-1 transcripts were additionally recognized in the straight tubules and
rete testis epithelium. Distinct S100 immunostaining was observed in the Sertoli cells,
endothelium of blood vessels and in the rete testis epithelium of fetal and adult testis. Laminin
was localized to the basal lamina of seminiferous tubules, blood vessels, myofibroblasts, and
rete testis. Although á -SMA was detected in smooth muscle cells of the blood vessels, no
immunoreactivity was seen in the peritubular cells during the whole gestation period. The
myofibroblasts surrounding the seminiferous tubules and rete testis showed intense positive
reaction for á -SMA in the adult testis. VEGF was detected in the acrosomes of the elongating
spermatids. Connexin 43 was localized to gap junctions between Leydig cells in the fetal and
adult life as well as to the seminiferous epithelium apical to spermatogonia and basal to
spermatocytes, a position correlating with Sertoli-Sertoli cell junctions. The detection of cells
positive for CD4, CD8, CD68 within the adult testis interstitium clearly indicate the presence
of lymphocytes and macrophages within this testicular compartment. GalTase showed
striking positive reaction in the Golgi complex of Sertoli cells, Leydig cells, and some
spermatocytes as well as at the cell membrane of elongating spermatids and in the simple
cuboidal epithelium of rete testis. ACE positive reaction was found in the prespermatogonia
(only at 6-10 cm CRL) and in fetal and adult testicular blood vessels. The functional
significance of these immunocytochemically-demonstrated proteins is discussed
Effects of different diets on growth performance, digestive enzyme activities and intestinal bacterial community of juvenile Chinese giant salamander (Andrias davidianus)
No full textThis study analyzed the growth performance, digestive enzyme activities and intestinal microbial community in HC group (fed with Chironomid larvae), HH group (fed with Chironomid larvae plus Earthworms) and QY group (fed with Earthworms) of juvenile Chinese giant salamander (Andrias davidianus) after farming for 60 days. The results showed that diet can affect the growth performance, digestive enzyme activities and intestinal mcirobiota composition of juvenile Chinese giant salamander. The growth performance in juvenile Chinese giant salamander of HC group was significantly higher than that of HH group and QY group. The ether extract content in muscles of juvenile Chinese giant salamander of HH group and QY group was significantly lower than that of HC group. The intestinal digestive enzyme activities in juvenile Chinese giant salamander of HC group were significantly lower than that of HH group and QY group. The intestinal microbial richness and diversity in juvenile Chinese giant salamander of HH group and QY group were significantly higher than that of HC group. The most dominant phylum of HC group and HH group was Firmicutes but QY group was Bacteroidota, and the most dominant genus of HC group was Clostridium_sensu_stricto_1 but HH group and QY group was Bacteroides. The 24 specific bacterial groups with different classification levels had significant differences in three diet groups of juvenile Chinese giant salamander and these specific bacteria were concentrated in Firmicutes, Proteobacteria and Bacteroidota. Thus, the above studies indicated that Chironomid larvae as diet can increase the growth performance of juvenile Chinese giant salamander, while the addition of Earthworms as diet can enhance digestive ability and change microbiota composition in intestine of juvenile Chinese giant salamander
An active origin method for affine matching
No full textAn active origin-based affine marching method was proposed in this paper. The basic idea is, the origin which has two adjustable parameters an the affine coordinate frame and the affine coordinate frame are both active. So the affine transformation between the model affine coordinate frame and the image affine coordinate frame has two adjustable parameters which will be applied to affine matching. Theoretical analysis and experiments demonstrated the proposed method being better than the conventional method.Computer Science, Software EngineeringCPCI-S(ISTP)
Matrix Factorizations for Reversible Integer Mapping
No full textReversible integer mapping is essential for lossless source coding by transformation. A general matrix factorization theory for reversible integer mapping of invertible linear transforms is developed in this paper. Concepts of the integer factor and the elementary reversible matrix (ERM) for integer mapping are introduced, and two forms of ERM---triangular ERM (TERM) and single-row ERM (SERM)---are studied. We prove that there exist some approaches to factorize a matrix into TERMs or SERMs if the transform is invertible and in a finite-dimensional space. The advantages of the integer implementations of an invertible linear transform are i) mapping integers to integers, ii) perfect reconstruction, and iii) in-place calculation. We find that besides a possible permutation matrix, the TERM factorization of an-bynonsingular matrix has at most three TERMs, and its SERM factorization has at most +1SERMs. The elementary structure of ERM transforms is the ladder structure. An executable factorization algorithm is also presented. Then, the computational complexity is compared, and some optimization approaches are proposed. The error bounds of the integer implementations are estimated as well. Finally, three ERM factorization examples of DFT, DCT, and DWT are given
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