bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of a melatonin implant on the free radical load in avian thydroid and its relation with thyroid hormonogenesis
Authors: Prakash Prem , Laloraya Malini , Pradeep Kumar G.
Published: July 2007

The primary aim of this study was to evaluate the effect of melatonin on the oxyradical load in avian thyroid. The superoxide free radicals have been spin trapped by EPR spectroscopy in the thyroid gland of Indian rock pigeon Columba livia following melatonin implantation for two weeks. Melatonin implantation resulted in augmentation in the levels of superoxde radical in the thyroid gland of pigeons with a concomitant decrease in the levels of the total superoxide dismutase activity. This was also associated with increased lipid peroxidation. Melatonin implantation caused a significant increase in plasma levels of glucose. Plasma levels of thyroxine (T4) and triiodothyronine (T3) were lower in the melatonin‐treated pigeons. However, the T3/T4 ratio was higher following melatonin implantation. Since iodination of tyrosine is an H2O2‐dependent phenomenon, the inhibition in the activity of SOD could lead to impaired thyroid hormone synthesis.
Purification and characterization of trichomaglin ‐ A novel ribosome‐inactivating protein with abortifacient activity
Authors: Chen Rong , Xu Yong‐zhen , Wu Jian , Pu Zheng , Jin Shan‐wei , Liu Wang‐yi , Xia Zong‐xiang
Published: July 2007

Trichomaglin, a novel ribosome‐inactivating protein, has been isolated from root tuber of a plant Maganlin (Trichosanthes Lepiniate, Cucurbitaceae). The isolation and purification procedure included ammonium sulfate precipitation, Sephadex G‐75 chromatography and CM‐Sephadex C‐50 chromatography. The protein was identified to be homogeneous by SDS‐PAGE and FPLC analysis. Its molecular weight is 24,673 dalton and isoelectric point is 5.8, determined by electrospray ionization mass spectroscopy and isoelectric focusing gel electrophoresis respectively. Trichomaglin can inhibit protein synthesis in rabbit reticulocyte lysate with ID50 of 10.1 nM. When rat ribosome was incubated with trichomaglin, a diagnostic RNA fragment appeared on polyacrylamide gel after ribosomal RNAs were treated with acidic aniline. It was concluded that trichomaglin is an RNA N‐glycosidase. In addition, it has been verified to be an abortifacient protein.
Aldosterone directly induces Na, K‐ATPase α1‐subunit mRNA in the renal cortex of rat
Authors: Seok Jeong‐Ho , Hong Jang‐Hee , Jeon Jong‐Rye , Hur Gang‐Min , Sung Ji‐Yeon , Lee Jae‐Heun
Published: July 2007

The change of blood pressure and the induction of Na, K‐ATPase α1‐subunit mRNA have been investigated in the renal cortex of aldosterone‐treated hypertensive rat. The increase of blood pressure by aldosterone‐treatment for 25 days was decreased by the treatment of amiloride or spironolactone. The level of Na, K‐ATPase α1‐subunit mRNA of the renal cortex in aldosterone‐treated rat was increased than that in the control, and its increase was repressed by treatment of spironolactone, but not altered by the treatment of amiloride. This result suggests that the increase of Na, K‐ATPase α1‐subunit mRNA in the renal cortex of aldosterone‐treated hypertensive rat may be related with the direct induction of Na, K‐ATPase mRNA without the increase of Na‐traffic through Na‐channel.
Preparation and characterization of β1‐bungarotoxin bispecific monoclonal antibody
Authors: Yang C. C. , Chan H. L.
Published: July 2007

A hybrid hybridoma (tetradoma) that produces bispecific monoclonal antibodies (mAbs)2, which recognize two different epitopes on the A chain of β1‐bungarotoxin (β1‐bgt) at peptide sequences 46‐51 and 100‐106, has been obtained by fusing two hybridoma cell lines. The bispecific mAb were observed to inhibit 98% of the enzymatic activity of β1‐bgt and neutralize its lethal toxicity completely. The avidity between the bispecific mAb and β1‐bgt was noted to be 4.5×1010 (liter/nmol), which is about 45‐150 folds higher than the avidity of its two parental mAbs. All the soluble complexes, obtained from bispecific mAb and β1‐bgt with different molar ratios, emerged in the void volume of size exclusion chromatography column, indicating multiple complexes of β1‐bgt and bispecific mAb were formed. Based on these results, it indicated that the binding of bispecific mAb with its two epitopes on β1‐bgt, which facilitates the immuno‐complex formation and enhances the avidity, also highly neutralizes the biological activity of β1‐bgt.
Squatting, Self-Immolation, and the Repatriation of Crimean Tatars
Authors: Uehling Greta
Published: July 2007

In the summer of 1978, a Crimean Tatar man named Musa Mamut walked out of his home in a small village in the Crimea toward a policeman waiting for him at his front gate. He was to be taken to the station for questioning, and quite possibly arrested for “violation of the passport regime.” But Mamut had already drenched himself with gasoline and, lighting a match, was engulfed in flames. He ran toward the policeman, who ran the other way. A deliveryman tripped Musa, and two friends who had been passing by extinguished the flames. His friends took him to the Simferopol city hospital, where he died six days later, never expressing any regret for what he did.
The “Revolutionary Girl with the Titus-Head”: Women's Participation in the 1919 Revolutions in Budapest and Munich in the Eyes of their Contemporaries
Authors: Johnson Eliza
Published: July 2007

The First World War represents a watershed in European women's history. The process of female integration into the industrial economy was both speeded up and given official endorsement as the massive mobilization of soldiers created great manpower shortages. The war seemed to accelerate and legitimate the process of female political integration as well, as most postwar European governments met the basic aims of the women's suffrage movement. Despite these advances, the First World War and the interwar years comprised an era which was fraught with conflicts over women's roles, rights, and responsibilities.
Site‐Directed Mutagenesis of Asp313, Glu315, and Asp391 Residues in Chitinase of Aeromonas Caviae
Authors: Lin Fu‐Pang , Chen Hsing‐Chen , Lin Chung‐Saint
Published: July 2007

Site‐directed mutagenesis was used to explore the roles of amino acid residues involved in the activity of chitinase from Aeromonas caviae .Kinetic parameters for 4‐methylumbelliferyl‐N, N‐diacetylchitobiose or 4‐methylumbelliferyl‐N,N, N‐triacetylchitotriose hydrolysis were determined with wild‐type and mutant chitinases. Chitinases with the mutations E315D (or Q) and D391E (or N) were severely impaired and had dramatically decreased kcat. However, the effect of the these mutations on the K m values were different. The function ofthe carboxylgroup of Asp313 was partially replaced by the amide ofAsn when the 4‐methylumbelliferyl‐N, N, N‐triacetylchitotriose substrate was used. Results indicated that Asp313, Glu315, and Asp391 might be the best candidates for the catalytic residues of chitinase A from Aeromonas caviae.
Isolation and Characterization of a Mutant Defective in the Production of Methanol Dehydrogenase from a New Restricted Facultative Methanol‐Oxidizing Bacterium
Authors: Kang Jin Kwon , Kim Si Wouk , Jeong Hye Gwang , Park Jong Kun , Park Yeal , Lee Jung Sup
Published: July 2007

A new restricted facultative methanol‐oxidizing bacterium Methylobacillus sp. strain SK1 (DSM 8269) was subjected to insertion mutagenesis studies with the transposon Tn5 to generate mutants deficient in the production of methanol dehydrogenase (MDH).The transposon was conjugally transferred into the methylotroph by using the triparental mating procedure. The mutants induced by Tn5 were selected directly from a plate containing succinate by using the allyl alcohol selection procedure. The transposition of Tn5 to the bacterium showed a moderate transposition frequency (10‐5‐10‐6).Southern hybridization analysis confirmed that the transposon Tn5 was inserted into the chromosomal DNA of the mutants. In addition, the mutants had no RNA transcripts produced from the mdh gene, as judged by Northern blot analysis. The mutants could neither grow on methanol nor produce MDH protein, as determined by Western blotanalysis with anti‐MDH antibody. These results suggest that Tn5 mutagenesis maybe a useful tool for the molecular analysis of a facultative methanol‐oxidizing bacterium.
5′‐Upstream Structure of the Gene Coding for Chicken Riboflavin‐Binding Protein and Its Relation to Estrogen Induction
Authors: Hamajima Susumu , Hirano Hiroko , Horiuchi Saburo , Ono Shigeru
Published: July 2007

To elucidate the mechanism of the estrogen‐dependent induction of chicken riboflavin‐binding protein (RfBP), we analyzed the 5′‐upstream structure of its gene. A noncoding exon exists there, and around this sequence, 9 widely spaced half‐palindromic estrogen‐response element (ERE) motifs (5‐GGTCA or 5‐TGACC) were found. Furthermore, an imperfect ERE‐like palindromic sequence (5′‐ATGTCANNNTGACAT‐3) was also found at the 2.25 kb upstream region. No consensus palindromic ERE was observed. By luciferase reporter assay, the regions containing the half ERE motifs and the imperfect ERE showed estrogen‐dependent enhancer activities, suggesting that these two characteristic sequences might confer estrogen‐inducibility upon the chicken RfBP gene. However the activities were lower than that of a consensus ERE. It remains uncertain whether these sequences act cooperatively.
Characterization of Cytostatically Active Glycosphingolipids Isolated from Thioglycollate‐Elicited Murine Macrophages
Authors: Schaade Lars , Ritter Klaus , Schiebel Hans‐Martin , Thomssen Reiner , Kleines Michael
Published: July 2007

Two acidic glycosphingolipids (gangliosides) derived from mouse macrophage membranes and separated by thin‐layer chromatography have a strong cytostatic effect on human and mouse tumor cells. The structure of the two gangliosides, named MphiG1 and MphiG2, was elucidated by application of physicochemical and immunochemical methods. Gas chromatography and mass spectrometry of MphiG1 and MphiG2 classified them as isomeric monosialogangliosides with ceramide moieties composed of sphingosine as the long‐chain base, C16 and C18 fatty acids, respectively, and a lacto‐tetraose backbone. For MphiG1, additional immunochemical findings led to the proposed structure IV3NeuAc‐nLcOse4Cer. The immunochemical reactions of MphiG2 suggest a branched structure for the oligosaccharide moiety.
Immunochemical Determination of Cellular Content of Translation Release Factor RF4 in Escherichia coli
Authors: Andersen Lars Dyrskjot , Moreno Juan Manuel Palacios , Clark Brian F. C. , Mortensen Kim Kusk , Sperling‐Petersen Hans Uffe
Published: July 2007

The biosynthesis of proteins in prokaryotes is terminated when a stop codon is present in the A‐site of the 70S ribosomal complex. Four different translation termination factors are known to participate in the termination process. Release factor RF1 and RF2 are responsible for the recognition of the stop codons, and RF3 is known to accelerate the overall termination process. Release factor RF4 is a protein involved in the release of the mRNA and tRNA from the ribosomal complex. Furthermore, RF4 is involved in the proofreading in the elongation step of protein biosynthesis. The cellular contents of RF1, RF2, and RF3 were determined earlier. Here we report the cellular content of RF4 in Escherichia coli to be ∼16 500 molecules per cell. The cells were grown in a rich medium and harvested in the beginning of the exponential growth phase. The quantifications were performed by using Western immunoblotting with radioactive iodinated streptavidin and biotinylated rabbit anti‐mouse immunoglobulins plus a highly specific monoclonal antibody against RF4 as first antibody.
Rearrangement in the Coding and 5′ Region of P53 Gene in Human Oral Tumors
Authors: Patnaik S. , Nayak B. K. , Das B. R.
Published: July 2007

Different postreplicative, transcriptional, and translational mechanisms responsible for p53 gene inactivation are slowly unfolding. Rearrangement of the p53 gene is a very rare event in human solid tumors and has been reported only in osteosarcomas. From our laboratory we have recently reported rearrangement only in the coding region of the p53 gene in breast tumors. In this report we have undertaken a systemic investigation of p53 in oral tumors. Results have shown rearrangement in the coding region of p53 in 20% of cases and in the 5′ region of p53 gene in 8% of cases. No allelic loss and amplification of p53 gene was observed in these tumor samples. In our earlier studies on breast tumors, we found no abnormality in the 5′ region of p53. However, in the present study we report for the first time rearrangement in the 5′ region of p53 in oral tumors. Correlation of p53 gene rearrangement with p53 expression of RNA and protein indicates that rearrangement in the 5′ region of p53 might not have a role in p53 expression. However, rearrangement in the coding region of p53 might play a critical role in controlling p53 gene activity in the process of tumorigenesis.
Cloning and Characterization of the Non‐Catalytic Heavy Chain of Mouse Complement Factor I Gene: Structure Comparison with the Human Homologue
Authors: Yun Young‐Sup , Goldberger Gabriel , Minta Joe O.
Published: July 2007

The above listed article appeared in issue 47(3), pages 493‐500, of Biochemistry and Molecular Biology International. Taylor & Francis regrets that in the original publication, a large portion of text was omitted from the article's Introduction. The following text represents the correct version of this article's Introduction.
The IL‐2 Receptor in Hemocytes of the Sea Mussel Mytilus galloprovincialis Lmk
Authors: Barcia R. , Cao A. , Arbeteta J. , Ramos‐Martinez J. I.
Published: July 2007

In the hemolymph of the sea mussel Mytilus galloprovincialis, two different cell types have been found. Rounded (RH) cells display a nucleus that is very large in relation to the cell size; spread (SH) cells have an expanded cytoplasm and multiple granules. We determined by flow cytometry that only the SH cell types express three interleukin‐2 receptor (IL‐2R) subunits. Mussel IL‐2Ralpha and IL‐2Rbeta subunits display a molecular weight similar to those in vertebrates tissues, whereas mussel IL‐2Rgamma is smaller than that in vertebrates. Both lipopolysaccharide and IL‐2 induce IL‐2Ralpha expression, and such induction depends on the concentration of both agonists.
Adeno‐Associated Virus Rep78 Binds to E2‐Responsive Element 1 of Bovine Papillomavirus Type 1
Authors: Chon Seung K. , Rim Byung M. , Im Dong S.
Published: July 2007

Adeno‐associated virus type‐2 (AAV‐2) is a helper‐dependent parvovirus that has been implicated in the inhibition of replication and oncogenic transformation of bovine papillomavirus type‐1 (BPV‐1) and other transforming DNA viruses. Previous studies have suggested that the Rep78 protein of AA V‐2 is a key player mediating this effect. In this report we have analyzed the effect of AAV‐2 Rep78 protein on the regulation of gene expression of a reporter gene under the control of the long control region (LCR) of BPV‐1. Our results show that Rep78 is capable of down‐regulating the promoter activity of the LCR in vivo in tissue culture cells. Inhibition of LCR activity in vivo suggested the need for Rep78 to bind to a region of the LCR promoter spanning the E2‐responsive elements of BPV‐1. This observation was further confirmed in vitro with gel shift assays showing specific binding of Rep78 to DNA oligonucleotides containing E2‐responsive element 1 (E2RE1) sequences of BPV‐1 LCR. Our results expand the understanding of the mechanism of trans‐regulation mediated by Rep78 and involving this protein and DNA sequences with complex secondary structure.
Expression of VEGF Splice Variants 144/145 and 205/206 in Adult Male Tissues
Authors: Burchardt Tatjana , Burchardt Martin , Chen Min‐Wei , Buttyan Ralph , De La Taille Alexandre , Shabsigh Ahmad , Shabsigh Ridwan
Published: July 2007

Currently, at least five different mRNA species encoding vascular endothelial growth factor‐A (VEGF‐A) have been characterized. These variants result from alternative splicing of the VEGF‐A transcript and encode human isoforms of VEGF protein of 121, 145, 165, 189, and 206 amino acids. In the rat, a similar profile of VEGF‐A splice variants has been described, each encoding one fewer amino acid than the human species. Studies of mammalian tissues have shown that these mRNA isoforms vary in abundance. Whereas VEGF 188/189, 164/165, and 120/121 (rat/human, respectively) are the predominant forms expressed in most tissues and cells examined, VEGF 144/145 and 205/206 are rare variants. Previously, VEGF 144/145 had been detected only in placental and uterine tissues and endometrial carcinoma cell lines, whereas VEGF 205/206 was detected only in fetal liver and placenta. Using an RTPCR technique, cDNA cloning, and sequencing, we have detected and confirmed the presence of mRNA encoding VEGF 144/145 and 205/206 in both adult rat lung and penis. Therefore, these lowabundance VEGF splice variants have a more diverse expression pattern than originally predicted.
Specific Domain of cGMP‐Dependent Protein Kinase Iβ but Not Iα Functions as a Transcriptional Activator in Yeast
Authors: Yuasa Keizo , Omori Kenji , Yanaka Noriyuki
Published: July 2007

Recently, cyclic GMP‐dependent protein kinase (cGK) was shown to translocate to the nucleus and regulate gene transcription. To determine whether cGK I proteins function as transcriptional activators, we produced the constructs of cGK Ialpha or Ibeta fused with the DNA binding domain of the yeast transcriptional activator GAL4. Here, we demonstrate that the amino‐terminal region of cGK Ibeta (amino acids 1‐107) exhibits transcriptional activation in yeast. However, full‐length cGK Ialpha and Ibeta and the amino‐terminal region of cGKIalpha had no transcriptional activation function. Amino acid replacement in the leucine zipper motif of the amino‐terminal region of cGK Ibeta substantially reduced transcriptional activation. These results suggest that the Ibeta‐specific region in cGK I proteins may interact with other proteins by way of the leucine zipper motif and has a transcriptional activation function.
Study on the Growth Inhibition of Human Multiple Myeloma Cells by an IL‐6Rα Mutant
Authors: Duan Jubao , Cai Xin , Wang Lihong , Zhang Shuangxi , Wang Jiaxi
Published: July 2007

DM650, a soluble human IL‐6Ralpha mutant with mutation of C277D/H280I, was previously shown to exhibit an antagonism to IL‐6, which resulted in growth‐inhibition of human multiple myeloma cell line AF‐10 autocrining as the growth‐stimulating factor. We investigated here the nature of the growth inhibition by examining cell apoptosis. Flow‐cytometric analysis of the DNA fragmentation demonstrated that 7.2% of the AF‐10 cells were apoptotic after 24 h of treatment with DM650. The constitutive gene expression of bcl‐2 in AF‐10 cells indicated that apoptosis suppressed by IL‐6 was independent of bcl‐2 regulation. The altered gene expression of c‐myc and p53 suggested that a novel apoptosis pathway, other than that suppressed by IL‐6, might be triggered by a complex of DM650 and IL‐6.
Macromolecular Mimicry in Translation Initiation: A Model for the Initiation Factor IF2 on the Ribosome
Authors: Moreno Juan Manuel Palacios , SØrensen Hans Peter , Mortensen Kim Kusk , Sperling‐Petersen Hans Uffe
Published: July 2007

Protein biosynthesis in bacteria is controlled by a number of translation factors. Recent data based on comparison of sequence and structure data of translation factors have established a novel hypothesis for their interaction with the ribosome: initiation, elongation, and termination factors may use a common or partly overlapping binding site on the ribosome in a process of macromolecular mimicry of an A‐site‐bound tRNA. This paper reviews structural knowledge and tRNA macromolecular mimicry involvement of translation initiation factor IF2. Furthermore, a model is proposed for the factor and its interaction with the ribosome during the formation of the translation initiation complex.
Mitochondrial Protein Lipoylation Does Not Exclusively Depend on the mtKAS Pathway of de Novo Fatty Acid Synthesis in Arabidopsis
Authors: Ewald Ralph , Kolukisaoglu Üner , Bauwe Ursula , Mikkat Stefan , Bauwe Hermann
Published: July 2007

The photorespiratory Arabidopsis (Arabidopsis thaliana) mutant gld1 (now designated mtkas-1) is deficient in glycine decarboxylase (GDC) activity, but the exact nature of the genetic defect was not known. We have identified the mtkas-1 locus as gene At2g04540, which encodes β-ketoacyl-[acyl carrier protein (ACP)] synthase (mtKAS), a key enzyme of the mitochondrial fatty acid synthetic system. One of its major products, octanoyl-ACP, is regarded as essential for the intramitochondrial lipoylation of several proteins including the H-protein subunit of GDC and the dihydrolipoamide acyltransferase (E2) subunits of two other essential multienzyme complexes, pyruvate dehydrogenase and α-ketoglutarate dehydrogenase. This view is in conflict with the fact that the mtkas-1 mutant and two allelic T-DNA knockout mutants grow well under nonphotorespiratory conditions. Although on a very low level, the mutants show residual lipoylation of H protein, indicating that the mutation does not lead to a full functional knockout of GDC. Lipoylation of the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase E2 subunits is distinctly less reduced than that of H protein in leaves and remains unaffected from the mtKAS knockout in roots. These data suggest that mitochondrial protein lipoylation does not exclusively depend on the mtKAS pathway of lipoate biosynthesis in leaves and may occur independently of this pathway in roots.
Mutations in CHLOROPLAST RNA BINDING provide evidence for the involvement of the chloroplast in the regulation of the circadian clock in Arabidopsis
Authors: Hassidim Miriam , Yakir Esther , Fradkin David , Hilman Dror , Kron Ido , Keren Nir , Harir Yael , Yerushalmi Shai , Green Rachel M.
Published: July 2007

The Arabidopsis circadian system regulates the expression of up to 36% of the nuclear genome, including many genes that encode photosynthetic proteins. The expression of nuclear‐encoded photosynthesis genes is also regulated by signals from the chloroplasts, a process known as retrograde signaling. We have identified CHLOROPLAST RNA BINDING (CRB), a putative RNA‐binding protein, and have shown that it is important for the proper functioning of the chloroplast. crb plants are smaller and paler than wild‐type plants, and have altered chloroplast morphology and photosynthetic performance. Surprisingly, mutations in CRB also affect the circadian system, altering the expression of both oscillator and output genes. In order to determine whether the changes in circadian gene expression are specific to mutations in the CRB gene, or are more generally caused by the malfunctioning of the chloroplast, we also examined the circadian system in mutations affecting STN7, GUN1, and GUN5, unrelated nuclear‐encoded chloroplast proteins known to be involved in retrograde signaling. Our results provide evidence that the functional state of the chloroplast may be an important factor that affects the circadian system.
Influence of vitamin E supplementation on spontaneous oxidized flavour of milk in dairy buffaloes
Authors: PANDA N , KAUR H
Published: July 2007

Twenty‐four Murrah buffaloes (60 days pre‐partum) were divided into four equal groups (T

1

, T

2

, T

3

and T

4

) and were supplemented with 0, 1000, 1500 and 2000 IU α‐tocopheryl acetate per day up to 30 days of lactation, and half of these doses from 30 to 60 days of lactation. Milk samples collected fortnightly were analysed for vitamin E, fat, and development of oxidized flavour, with and without copper addition by a panel of judges, and chemically by the thiobarbituric acid test. Scores for oxidized flavour ranged from 0 to 10 with 0–4 as definite, 5–7 as light and 8–10 having no defect. The α‐tocopherol content in milk fat (µg/g) averaged 20.55, 25.56, 29.98 and 31.38 in T

1

, T

2

, T

3

and T

4

groups, respectively. The addition of Cu in the milk significantly increased milk fat oxidation. Better stability of milk in T

3

and T

4

groups was observed, which might be due to a higher level of milk α‐tocopherol. Addition of 1500 IU α‐tocopheryl acetate in the diet of buffaloes helped in improving the oxidative stability of milk.
Proteolysis in ultra‐filtered and conventional Iranian white cheese during ripening
Authors: HESARI JAVAD , EHSANI MOHAMED R , MOSAVI MOHAMED A E , McSWEENEY PAUL L H
Published: July 2007

Conventional and ultra‐filtered (UF) Iranian white cheeses were made with almost identical gross chemical composition and the extent and characteristics of proteolysis were studied during ripening. UF cheeses exhibited a lower rate of development of pH 4.6‐soluble nitrogen than conventional cheeses. The rates of degradation of αs1‐casein and particularly β‐casein were lower in UF cheeses than in conventional cheeses. Plasmin activity was lower in UF cheeses than that in conventional cheese, whereas coagulant activity was higher in the former. Noticeable qualitative and quantitative differences were observed in reverse‐phase high performance liquid chromatography (RP‐HPLC) peptide profiles between UF and conventional white cheeses and chemometric analysis of peak height data distributed the cheeses into two separate groups. The levels of free amino acids in UF cheeses were lower than in conventional cheeses. Lower peptide degradation and production of amino acids suggested slower ripening, which may have been associated with the weak aroma development characteristic of UF cheeses.
Effects of Additive on the Microwave Synthesis of AlN Powder
Authors: Zeng Xiofeng , Qian Duanfen , Li Weifeng , Peng Hu , Lei Chun , Liu Xuanyong
Published: July 2007

In this paper, a series of aluminum nitride powders were synthesized using a microwave synthesis method with various additives. The effects of additives on the nitridation of aluminum powder by microwave processing were studied. The results showed that the pure AlN powder with regular and fine grains could be obtained at a temperature of 1050°C for 30 min by the mixed additive under atmospheric pressure of nitrogen. The mixed additive composed by ammonium fluoride and zinc granules played a vital role in the microwave synthesis process.
Effects of Oxygen on Biofilm Formation and the AtlA Autolysin of
Streptococcus mutans
Authors: Ahn Sang-Joon , Burne Robert A.
Published: July 2007

The
Streptococcus mutans atlA
gene encodes an autolysin required for biofilm maturation and biogenesis of a normal cell surface. We found that the capacity to form biofilms by
S. mutans
, one of the principal causative agents of dental caries, was dramatically impaired by growth of the organism in an aerated environment and that cells exposed to oxygen displayed marked changes in surface protein profiles. Inactivation of the
atlA
gene alleviated repression of biofilm formation in the presence of oxygen. Also, the formation of long chains, a characteristic of AtlA-deficient strains, was less evident in cells grown with aeration. The SMu0629 gene is immediately upstream of
atlA
and encodes a product that contains a C-X-X-C motif, a characteristic of thiol-disulfide oxidoreductases. Inactivation of SMu0629 significantly reduced the levels of AtlA protein and led to resistance to autolysis. The SMu0629 mutant also displayed an enhanced capacity to form biofilms in the presence of oxygen compared to that of the parental strain. The expression of SMu0629 was shown to be under the control of the VicRK two-component system, which influences oxidative stress tolerance in
S. mutans
. Disruption of
vicK
also led to inhibition of processing of AtlA, and the mutant was hyperresistant to autolysis. When grown under aerobic conditions, the
vicK
mutant also showed significantly increased biofilm formation compared to strain UA159. This study illustrates the central role of AtlA and VicK in orchestrating growth on surfaces and envelope biogenesis in response to redox conditions.
Circadian rhythms in myocardial metabolism and contractile function: influence of workload and oleate
Authors: Durgan David J. , Moore Michael W. S. , Ha Ngan P. , Egbejimi Oluwaseun , Fields Anna , Mbawuike Uchenna , Egbejimi Anu , Shaw Chad A. , Bray Molly S. , Nannegari Vijayalakshmi , Hickson-Bick Diane L. , Heird William C. , Dyck Jason R. B. , Chandler Margaret P. , Young Martin E.
Published: July 2007

Multiple extracardiac stimuli, such as workload and circulating nutrients (e.g., fatty acids), known to influence myocardial metabolism and contractile function exhibit marked circadian rhythms. The aim of the present study was to investigate whether the rat heart exhibits circadian rhythms in its responsiveness to changes in workload and/or fatty acid (oleate) availability. Thus, hearts were isolated from male Wistar rats (housed during a 12:12-h light-dark cycle: lights on at 9 AM) at 9 AM, 3 PM, 9 PM, and 3 AM and perfused in the working mode ex vivo with 5 mM glucose plus either 0.4 or 0.8 mM oleate. Following 20-min perfusion at normal workload (i.e., 100 cm H2O afterload), hearts were challenged with increased workload (140 cm H2O afterload plus 1 μM epinephrine). In the presence of 0.4 mM oleate, myocardial metabolism exhibited a marked circadian rhythm, with decreased rates of glucose oxidation, increased rates of lactate release, decreased glycogenolysis capacity, and increased channeling of oleate into nonoxidative pathways during the light phase. Rat hearts also exhibited a modest circadian rhythm in responsiveness to the workload challenge when perfused in the presence of 0.4 mM oleate, with increased myocardial oxygen consumption at the dark-to-light phase transition. However, rat hearts perfused in the presence of 0.8 mM oleate exhibited a markedly blunted contractile function response to the workload challenge during the light phase. In conclusion, these studies expose marked circadian rhythmicities in myocardial oxidative and nonoxidative metabolism as well as responsiveness of the rat heart to changes in workload and fatty acid availability.
A Phenomenological Investigation of Altruism as Experienced by Moral Exemplars
Authors: Mastain Lisa
Published: July 2007

This research study used descriptive phenomenological methods (Giorgi, 1989, Methods, 1, 39-61) to investigate and document the lived experience of altruism as described by moral exemplars. Six moral exemplars wrote descriptions of situations in which they engaged in spontaneous altruism. Altruism was defined for the purpose of this study as a motivational state with the ultimate goal of increasing another's welfare (Batson, 1991, The altruism question: Toward a social psychological answer). These descriptions were then expanded and clarified through follow up interviews. The results of this descriptive phenomenological analysis produced two structures: the structure of the lived experience of altruism as described by moral exemplars, and the structure of the lived experience of helping as described by moral exemplars. The differences between these two structures suggest that altruistically motivated pro-social behavior is more committed, extensive and effective than egoistically motivated helping, and results in a higher level of concern for the long-term well-being of the individuals helped. Although differentiated by primary motivations, altruistic or egoistic, both structures identify the motivating factors of empathy, personal historical life experiences, moral values, and personal identity as essential to the experience of assisting another individual in need.
Performance analysis of parallel machines using multi‐read memory
Authors: Amano Hideharu , Chikawa Junji , Yoshida Takaichi , Also Hideo
Published: July 2007

The multi‐read memory is a special type of shared memory which provides multiple data copies and allows multiple PUs to read data simultaneously. This paper analyzes the behavior of parallel machines using the multi‐read memory and provides some methods to determine their performance. First, a Markov chain model is applied to n ‐ n systems in which the number of copies is the same as that of PUs. Then a less complex expectation model is introduced as well as approximate expressions for the performance and it is shown that the results are almost the same as those of the Markov chain model. The paper also analyzes n ‐ m systems in which the number of copies is less than that of PUs and obtains approximate expressions for the performance. The results of the behavior analysis clarify the upper limit of the number of PUs, the optimum number of copies and other useful results for implementation of the systems.
Segmentation method of document images by two‐dimensional fourier transformation
Authors: Hase Masahiko , Hoshino Yasushi
Published: July 2007

A processing method is described for the document image composed of characters, graphics and photographs, extracting those regions by the following procedures. (1) Two‐dimensional Fourier transformation is performed for the entire image, the angle of the character lines is corrected utilizing the peak coordinate of the transform result, and the period of the character lines is calculated. (2) Based on the real and imaginary parts of the transform result, the coordinates for the characters are calculated. (3) The two‐dimensional Fourier transformation is performed for the subpictures determined by the character period. The entire document is scanned and the regions are detected by determining the existence of the peak corresponding to the character‐line period. It is shown by experiment that the angle of the line can be detected with accuracy within 2 degrees between ‐45 and +45 degrees. An experiment was performed for the image (journal article and patent document) composed of graphics and photographs, and it is verified that the method can extract the regions with sufficient accuracy.
Analysis of line drawings based on automatically inferred grammar and its application to chest X‐ray images
Authors: Nakayama Akira , Yoshida Yuuji , Fukumura Teruo
Published: July 2007

This paper proposes a syntactic method of analysis for line drawings, which extracts the required line drawings from the noisy ones and represents them as a set of strings. The method utilizes the generative grammar, which is inferred automatically. In the proposed method of analysis, the noise and the irregular components in the symbol string are separated and smoothed out based on syntactic information, making it possible to extract the required line drawings. To evaluate the effectiveness of the proposed method, it is applied to the extraction of the rib‐center (costal) pattern from 30 thinned chest X‐ray images. The result indicated the usefulness of the proposed method.
Optimization of functional language ASL/F programs
Authors: Seki Hiroyuki , Taniguchi Kenichi , Kasami Tadao
Published: July 2007

Functional languages are known to have such advantages as simply defined semantics. However little study has been made regarding compilation or optimization methods for efficient execution on a conventional machine. This paper formulates some optimization methods compiling a functional language ASL/F program into an object program in a procedural language, and further gives some sufficient conditions to perform these optimizations. It introduces “needed‐argument‐first computation” and “globalization of sorts (data types),” which are new optimization methods and have not been discussed before. Sample programs which are compiled and executed by an experimental compiler perform these optimization methods, as well as elimination of duplicated computation for common subterms, elimination of tail recursion, and rewriting in compilation. These experimental results show that execution time and dynamic memory space requirement of the object program are reduced by these optimizations and the program can be executed in almost the same time as an equivalent program written in a procedural language such as PASCAL.
An n‐dimensional region data management system using combined tree structures
Authors: Ohsawa Yutaka , Sakauchi Masao
Published: July 2007

In this paper we describe management system for region data using tree structures. Though the region data are divided into spatial data and alpha‐numerical data, we are primarily concerned with the management of spatial data. In the proposed method the cellular data obtained by partitioning them into equally spaced meshes (the cells have regional IDs as values) are managed by using combined two‐step binary tree structures. First, the three structures of the first step (primary structures) are constructed with the following procedure. (1) The object plane is recursively partitioned into two equal parts alternating vertically and horizontally, so that the number of kinds of regions contained in a small rectangle is two or less. (2) This partition procedure is represented by using a tree structure with two children (degree 2). Also, a secondary structure serves to distinguish the patterns of two regions in a rectangle given by a leaf of the primary structure and the representation by a simplified binary tree is used. The tree structures have the following characteristics. (1) Since global data on the whole object plane are obtained by the primary structure, range search can be conducted efficiently. (2) By using the simplified binary tree representation for the secondary structures, the total number of nodes is reduced to less than one half of that in an ordinary binary tree representation. (3) Since the operations for searching or overlaying are simplified, they can be executed at high speed.
An algorithm to perform the rank filter and its applications
Authors: Nakayama Tadayoshi , Yokoi Shigeki , Toriwaki Jun‐ichiro
Published: July 2007

The median filter is used frequently in image processing for smoothing while retaining edges. This paper describes an efficient method to calculate the rank filter, which is a generalization of the median filter and includes it as a special case. The presented method is simpler than the method proposed previously by Danielsson. A strict proof is given for its validity. An application to the construction of a logical circuit realizing the algorithm is also described.
A restoration algorithm of fingerprint images
Authors: Nakamura Osamu , Nagaoka Yoshihiro , Minami Toshi
Published: July 2007

This paper discusses noise elimination and restoration of the ridge structure of fingerprints in preprocessing for automatic fingerprint identification. The basic idea is as follows. The object image is partitioned into 64 × 64 unit regions with 8 pixels as edge. After estimating the locations of the ridges and valleys the restoration is performed by gray‐scale correction with different weights for each location. The processing is roughly divided as follows: (1) separation of background; (2) detection of ridge direction (quantized in 8 directions); (3) detection of ridge and valley locations; and (4) correction of gray‐scale value. Processing (2) greatly affects the later accuracy of detection and correction and requires high accuracy. In this paper the direction of the ridges is estimated hierarchically both from the local and global views and then is corrected by applying stochastic relaxation. As a result of experiment for 28 fingers (75903 unit regions) 99.00% of the estimates were within direction error of 0 and ±1. Considering that true correspondence of feature points was achieved for more than 73% between the later processed result and the original image, the above value is quite satisfactory for identification, verifying the usefulness of the proposed method.
Encoding of line drawings with multiple hexagonal grid chain code
Authors: Shinohara Katsuyuki , Minami Toshi
Published: July 2007

This paper discusses the encoding of line drawings using a hexagonal quantization grid. When an efficient encoding of line drawings is required in general, one must seek the encoding method which minimizes the code assigned to the unit length of the line‐drawing, under the constraint for the quantization error. The multiple square grid chain code, which was already proposed, is one such encoding method. This paper describes the result of a study on the multiple hexagonal quantization grid, which is more efficient than the former method. In those methods, the quantization grid is not fixed. The quantization points are arranged on the edge of the grid, and the quantization is made more efficient by adjusting the point of quantization grid connections according to the previous situation of quantization. The rate‐distortion value of the multiple hexagonal grid chain code is shown to be approximately 0.7 times that of the multiple square grid chain code and approximately 0.45 times that of Freeman's chain code. The reason for the differences are discussed in some detail, and the actual algorithm and the processing time are described, considering the real‐time property of the code.
Object recognition sensor using ring pattern method for robotic applications
Authors: Ohya Jun
Published: July 2007

To provide robots with a flexibility of operation, it is necessary to develop a sensor which can recognize the distance to the object as well as its surface shape. This paper investigates the robot sensor using the ring pattern method, where a circular pattern is projected on the object and the location and the shape of the object is recognized by analyzing the distortion of the projected pattern. In the proposed system, a conical beam is projected from a ring projector, and by varying the azimuth angle of the cone, both the distance and the shape are recognized. The distance to the object is determined utilizing the geometrical relation when the beam is focused to a point on the object surface. For the shape, the ring pattern is approximated by ellipses, and the shape is analyzed by the distributions of this parameter. The three‐dimensional data are obtained from the distortion of the projected pattern from the circle, which would have been obtained by projecting the light on a plane which is parallel to the projector plane and passing through the point of the measured distance. The measurement is made by scanning the beam on the object, and the result of recognition for the whole object is represented by the surface patching. An experimental system was constructed based on the proposed principle, using 6 projectors. A satisfactory result was obtained for the measurements of distance, shape and inclination of the plane. Using a book as the object, a grid scanning is made and the result is represented by the surface patching. It is seen that the edge and the curve of the paper can be recognized.
Determining three‐dimensional structure from image sequences given by horizontal and vertical moving camera
Authors: Yamamoto Masanobu
Published: July 2007

Stereovision is the simplest method for acquiring three‐dimensional information. A problem then is that sometimes it is difficult to establish a correspondence between the left and right images in such cases as: (1) multiple correspondence; (2) occlusion; (3) positional reversals; and (4) horizontal edge. This paper proposes a method to determine the three‐dimensional structure of the scene from the sequences of images obtained by moving camera. First, a two‐dimensional image is constructed from the sequence of images in which the apparent locus of motion is represented as a segment. The corresponding problem here is simplified as the detection of segments on the synthetic image. By examining the relations among the detected segments, the occlusions can be detected, and the correspondence can be established where positional reversals occur. By moving the camera not only in one direction, but also in orthogonal directions, the unique correspondence can be established, independently of the direction of the edge. An input system was constructed which can accept a large number of stereo image sequences with a high speed, and a complex three‐dimensional structure of the scene was actually restored.
Fault‐tolerant network routings for (k + 1)‐node connected and (k + 1)‐edge connected graphs
Authors: Wada Koichi , Kawaguchi Kimio , Luo Yupin
Published: July 2007

Improving the reliability of information transmission in communications networks and computer networks economically and efficiently is an important subject. A communications network (computer network) is represented by a graph whose nodes and edges correspond to switching offices (computers) and links, respectively, and communication between two nodes is made through a path in a graph. Routing is defined as the determination of a communication path between two nodes in a network. The diameter of the surviving route graph, where two nonfaulty nodes are connected by an edge if there are no faults on the route between them, could be one of the fault‐tolerant measures for a routing. In this paper, for the routing of any (k + 1)‐node connected graph G defined by Dolev et al., we discuss the upper and lower bounds of the diameter of the surviving route graph for any fault. We can also construct a routing for (k + 1)‐edge connected graph G such that the diameter of the surviving route graph is constant for any edge faults.
Representation of problem—solving processes by a model of associative processor hasp. a case study for the process of addition
Authors: Hirai Yuzo , Ma Qing
Published: July 2007

This paper aims at a constructive description of which neural network model can represent the human problem‐solving process and how the process is related to the various human memories by what context. From such a viewpoint, a neural network model is constructed for the representation of the problem‐solving process. In this paper, a model for the addition process is constructed as the first step, using the associative memory model HASP (human associative processor) proposed by one of the present authors. The model is composed of the following components: the procedure memory, which stores and retrieves the procedures of the addition; semantics memory, which stores the knowledge about the addition such as 2 + 2 = 4; the working memory, which temporarily stores the external and internal information; and the goal memory, which stores the problem‐solving process as a chain of subgoals, and manages the flow of procedures from one higher level in the control hierarchy. In this study, a computer simulation was performed for the addition processes for several numbers with multiple digits, and it is shown that the addition process can be represented. Then the computer simulation is made for the generation of four kinds of bugs in the addition. It is shown that the bug generation can be represented by the model.
Dissipation conditioned stochastic modeling of scalar concentration fluctuations in turbulent flows
Authors: Reynolds A. M.
Published: July 2007

A dissipation conditioned stochastic model for the evolution scalar concentration fluctuations in turbulent flows is formulated. The model reproduces accurately observed distributions of scalar concentrations and the extreme intermittency of scalar time derivatives. The spectral function for scalar concentration fluctuations is consistent with the predictions of Kolmogorov-Obukhov-Corrsin theory.