bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantification of distinct molecular species of platelet activating factor in ulcerative colitis
Authors: Thyssen Erik , Turk John , Bohrer Alan , Stenson William F.
Published: May 2007

The aim of this study was to characterize the synthesis and metabolism of platelet activing factor (PAF, 1‐O‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine) by colonic mucosa from patients with ulcerative colitis and healthy individuals. Tissue was obtained by endoscopic biopsy and by scraping the mucosa from surgical resections. Tissue was assayed for the various molecular species of PAF and its biologically inactive metabolite lyso‐PAF using gas chromatography/mass spectrometry. Mucosa from surgical resections for ulcerative colitis contained C16:0 PAF (mean=156 ng/g of mucosa), but not C18:0 PAF. PAF was not identified in mucosa from normal surgical resections or in endoscopic biopsies from either patients with ulcerative colitis or normal individuals. Both C16:0 lyso‐PAF and C18:0 lyso‐PAF were found in mucosa from normal and ulcerative colitis surgical resections and in endoscopic biopsies from ulcerative colitis and normal tissue. Levels of lyso‐PAF were similar in ulcerative colitis and normal mucosa. Incubation of mucosa from areas of active inflammation in ulcerative colitis with the calcium ionophore A23187 increased the levels of C16:0 PAF by 2–3 fold and also increased the levels of C16:0 lyso‐PAF. Addition of3H‐PAF to endoscopic biopsies from either normal individuals or patients with ulcerative colitis resulted in hydrolysis to3H‐lyso‐PAF. The data on colonic mucosal levels of PAF are consistent with the results of earlier studies measuring PAF in patients with ulcerative colitis by bioassay. This study examines the synthesis and metabolism of specific molecular species of PAF in ulcerative colitis for the first time.
Role of lipids in development of noninsulin‐dependent diabetes mellitus: Lessons learned from pima indians
Authors: Tataranni P. A. , Baier L. J. , Paolisso G. , Howard B. V. , Ravussin E.
Published: May 2007

We studied the role of lipids in the pathogenesis of nonlinsulin‐dependent diabetes mellitus (NIDDM) in Pima Indians. High plasma levels of nonesterified fatty acid (NEFA) predicted development of NIDDM, but this effect cannot entirely be explained by the glucose‐fatty acid cycle. Dyslipidemia, although often associated with diabetes, did not seem to predict NIDDM, and might rather be associated with or the consequence of insulin resistance. In some individuals, a single amino acid substitution in the intestinal fatty acid binding protein could result, in increased rates of intestinal absorption of dietary NEFA and thereby contribute to increased lipid‐oxidation rates and insulin resistance.
Characteristics of fats in Japanese diets and current recommendations
Authors: Sugano Michihiro
Published: May 2007

Although there is no firm evidence to support the “ideal” or even “appropriate” healthy level of dietary fat, the habitual fat consumption pattern in Japan seems to be a criterion for the recommended allowance both in the quantitative and qualitative points of view as judged from the life expectancy and the incidence of degenerative diseases. The new recommended dietary allowance of Japan, fifth revision effective for five years starting in 1995, adopted dietary fat levels of 20–25 energy percent, the ratio of saturated, monounsaturated, and polyunsaturated fatty acids at 1∶1.5∶1 and the ratio of n‐6/n‐3 at 4. The recommended fat level is similar to that previously consumed in Japan, and is even lower than that in diets used to treat hyperlipidemia in Western countries, current recommendations in those countries being 30 energy percent fat. Convincing data for the beneficial effects of n‐3 polyunsaturated fatty acids on human health, in particular for healthy people, have been presented in only a few reports. However, the recommended n‐6/n‐3 ratio of 4 seems reasonable compared with the ratio of around 10 in other developed countries. In this context, it is more important to fully understand the nutritional and physiological roles of fat in healthy people rather than in those with chronic disease. At present, the low‐fat dietary pattern in Japan appears to be a healthy way of eating.
The reaction of ethylene oxide with oleic acid
Authors: Stockburger G. J. , Brandner J. D.
Published: May 2007

The base‐catalyzed reaction of ethylene oxide with oleic acid can be divided into two stages. The first stage consists of a slow reaction of oleic acid with ethylene oxide to form principally ethylene glycol monooleate; other reactions such as esterification, transesterification and polyglycol formation lag behind. In the second stage, after the addition of approximately one mole of ethylene oxide, the reaction accelerates and transesterification equilibrium is rapidly attained. The composition of products containing several molecules or more of ethylene oxide can be calculated satisfactorily on the assumption of random addition of ethylene oxide and random esterification of the hydroxyl groups. The uncatalyzed reaction is much slower and transesterification equilibrium is attained slowly, if at all. A reaction mechanism based on the difference in basicities of the carboxylate and alkoxide ions (and the relative rates of the competitive ethylene oxide reactions) is presented for the base‐cat‐alyzed reaction.
Hydrolysis of corn oil by lipase fromHelminthosporium maydis race T
Authors: Bennett G. A. , Freer S. , Shotwell O. L.
Published: May 2007

Corn oil was used as the sole carbon source for growth ofHelminthosporium maydis Race T (NRRL 5128) in shaken flasks at 28 C. Oil recovered by hexane extraction from culture medium and mycelia at 2‐day intervals was analyzed by thin layer chromatography and gas chromatography. Triglyceride content of the oil was reduced, whereas free fatty acid, monoglyceride, and diglyceride contents increased as a result ofHelminthosporium maydis growth. Free sterol and steryl ester contents were unaffected. Lipase production was demonstrated byHelminthosporium maydis cells grown on corn oil, but the enzyme was not detected in cells grown on sucrose.
Chemical composition and lipoxygenase activity in soybeans as affected by genotype and environment
Authors: Chapman G. W. , Robertson J. A. , Burdick D. , Parker M. B.
Published: May 2007

Environmental and genetic influences on the chemical composition and lipoxygenase activity of 24 soybean genotypes (groups IV‐S and V) were determined. The soybeans were grown at two climatically different locations within the state of Georgia. Oil and protein contents and fatty acid composition of the oil in soybeans were affected by the environment. Five genotypes from group IV‐S has a fatty acid composition of the oil different from the other genotypes in the group. These differences appeared to be genetically controlled. The level of lipoxygenase activity in soybeans also appeared to be genetically controlled and not influenced by the environment. The study indicated that soybean genotypes could be selected for a specific climatic region based on oil fatty acid composition and lipoxygenase activity.
Storage of cottonseed and peanuts under conditions which minimize spectrophotometric changes in the extracted oil
Authors: Pons Walter A. , Murray Mildred D. , O'Connor Robert T. , Guthrie John D.
Published: May 2007

Cottonseed was stored for over a year without appreciable change in red gossypol content by adjusting the moisture content to 8% or less and placing in closed containers at 1° or at −18°C. Cottonseed stored at room temperature, 27°C., showed a large increase in red gossypol content.

Cottonseed stored in the above manner at 1° or at −18°C. showed little or no increase in the non‐gossypol absorption of the extracted oil at 236 mμ, the region of diene conjugation. This property of the extracted oil showed a large increase when cottonseed was stored at room temperature, 27°C.

Gossypol dissolved in cyclohexane has spectrophotometric extinction coefficients (concentration in g. per liter, solution depth 1 cm.) of 207, 70, and 40 at the maxima at 236 mμ, 286 mμ, and 358 mμ, respectively.

The extracted oil from peanuts stored for over four years at room temperature, 27°C., showed a much greater absorption in the region of 227 mμ to 234 mμ than did peanuts stored for the same time at 1° or at −18°C.
Partial hydrogenation of linseed oil by a continuous process
Authors: Smith Frank G.
Published: May 2007

Alkali refined linseed oil was partially hydrogenated, using both continuous and batch processes. The continuous process was carried out in a series of Votator machines, using Rufert nickel catalyst, presures up to 145 psig. and temperatures up to 400°F.

The continuous hydrogenation of linseed oil under the most selective conditions possible, using the Votator equipment, shows little selectivity between the linolenic and linoleic acid radicals. A pronounced selectivity is observed between oleic and the more unsaturated acid radicals. Under selective conditions of hydrogenation of linseed oil about 31% of the hydrogenated linolenic acid radical is transformed into 9–15 linoleic acid while the remainder of the linolenic acid goes to oleic acid in either one or two steps.

Batch hydrogenation yields oils of superior nonyellowing characteristics over comparable oils prepared by the continuous process.

The hydrogenated linseed oils were tested in both clear and pigmented alkyds where they displayed superior non‐yellowing characteristics over the original linseed oil and, in many instances, over that of soya bean oil.

The yellowing of oils and alkyds appears to be a function of both 1) the quantity of fatty acids more unsaturated than oleic present in the oil and 2) the ratio of the quantity of linolenic acid radicals to linoleic acid radicals present.
Rapid methods for determination of free fatty acids contents in fatty oils
Authors: Panduranga Rao B. , Thirumala Rao S. D. , Reddy B. R.
Published: May 2007

Rapid qualitative and quantitative methods for determining the free fatty acid (FFA) contents in common oils and fats are reported. Qualitative method is based on the type of color developed in the presence of BDH indicators (Universal and “678”) when a known excess of alkali is added to an alcoholic solution of oil or fat. By this method, low (0.0–0.25), medium (0.26–0.99) and high (1.0 and above) FFA levels in fatty oils may be distinguished. Quantitative method is a simplified modification of the usual procedure of determining the FFA contents of oils and fats by titration against standard alkali solution in the presence of BDH Universal or “678” indicator. The results of the rapid methods agree well with those of the standard AOCS method.
Adsorption analysis of lipids. III. Synthetic mixtures of ethyl stearate, oleate, linoleate, and linolenate
Authors: Dutton Herbert J. , Reinbold Catherine L.
Published: May 2007

The adsorption analysis of six binary mixtures composed of ethyl stearate, ethyl oleate, ethyl linoleate, and ethyl linolenate has been studied on alumina columns. Distillation methods have been shown by other workers to fractionate the stearate‐oleate system but not the oleate‐linoleate system. Application of the adsorption analysis technique resulted in fractionation of all six systems including the oleate‐linoleate mixture.

Measures of the performance of the columns were obtained by dividing the eluate into two portions at the point in the fractionation at which the starting composition was reached. The first component to be eluted from each of the six pairs was obtained in the first fraction with an average purity of between 68 and 83%. The second component was obtained in the second fraction with average purity of 61 to 76%. The first component to be eluted was obtained in higher purity than the second. The efficiency of separation of pairs appeared to depend on the difference in degree of unsaturation of the components. Overall recoveries of esters from the columns ranged from 71.8 to 87.5%.
Oligopolymer, diglyceride and oxidized triglyceride contents as measures of olive oil quality
Authors: Gomes Tommaso
Published: May 2007

The objective of this study was to test the qualities of olive oils of different commercial grades by quantifying oligopolymer compounds by high‐performance size‐exclusion chromatography (HPSEC). The method required no sample manipulation and was accurate and rapid. The mean level of oligopolymers in refined olive oils was 0.70% and was more than twice as high in refined olive pomace oils. Conversely, edible virgin olive oils had no oligopolymer compounds. HPSEC analyses of polar compounds by silica gel column chromatography also allowed determination of oxidized triglycerides and partial glycerides, which help define levels of oxidative degradation and hydrolysis.
Anti‐proliferation and apoptosis induced by a novel intestinal metabolite of ginseng saponin in human hepatocellular carcinoma cells
Authors: Ming Yan‐lin , Song Gang , Chen Liang‐hua , Zheng Zhi‐zhong , Chen Zhong‐yan , Ouyang Gao‐liang , Tong Qing‐xuan
Published: May 2007

20‐O‐(β‐d‐glucopyranosyl)‐20(S)‐protopanaxadiol (IH‐901), a novel intestinal bacterial metabolite of ginseng protopanaxadiol saponins, is reported to induce apoptosis in a variety of cancer cells. We purified the compound and measured its in vitro anti‐tumor activity. IH‐901 inhibited cell growth of human hepatocellular carcinoma SMMC7721 cells in a dose‐ and time‐dependent manner. We also found that IH‐901 induced apoptotic cell death concurrent with cell cycle arrest in G0–G1 phase in SMMC7721 cells. At the molecular level, we show that IH‐901 upregulates cytochrome c, p53, and Bax expression, and downregulates pro‐caspase‐3 and pro‐caspase‐9 expressions in a dose‐dependent manner, while the levels of Bcl‐2 and Bcl‐XL were unchanged in IH‐901‐treated SMMC7721 cells. These results provide significant insight into the anticarcinogenic action of IH‐901.
Generation and characterization of mouse parthenogenetic embryonic stem cells containing genomes from non‐growing and fully grown oocytes
Authors: Shao Hua , Wei Zhuying , Wang Lingling , Wen Lihua , Duan Biao , Mang Lie , Bou Shorgan
Published: May 2007

It is known that oocytes can be activated without male contribution in vitro and develop to blastocysts which are used to isolate parthenogenetic embryonic stem cells. Unfortunately, differentiation capacity of the parthenogenetic embryonic stem cells was rather lower than fertilized embryos derived ES cells, which might be the result of the absence of male genome. It had been found that some maternally expressed genes were repressed and some paternally expressed genes were expressed in the non‐growing oocytes. Therefore, maternal genome from non‐growing oocytes can partially act as “sperm genome”. In the present study, parthenogenetic blastocysts containing genome from non‐growing and fully grown oocytes (named as NF‐pBlastocysts) were produced by germinal vesicle transfer, and three newly established parthenogenetic embryonic stem (named as NF‐pES) cell lines were derived from the resulting parthenogenetic blastocysts. All three NF‐pES cell lines were positive for ES cell markers, such as alkaline phosphatase (AKP), stage‐specific embryonic antigen 1 (SSEA‐1) and octamer‐binding transcription factor (Oct‐4). They have a normal chromosome karyotype (40) and can be maintained in an undifferentiated state for extended periods of time. When NF‐pES cells were injected into severe combined immunodeficient mice, teratomas with all three embryonic germ layers were obtained. The in vitro differentiation potential of NF‐pES cells was analyzed by embryonic bodies (EB) formation. The expression of germ layer markers, such as nestin (ectoderm), desmin (mesoderm), and α‐fetoprotein (endoderm) demonstrated that the NF‐pES cells can differentiate into all three germ layers.
Sensitivity to microcystins: A comparative study in human cell lines with and without multidrug resistance phenotype
Authors: De Votto Ana Paula Souza , Renon Viviane Plasse , Yunes João Sarkis , Rumjanek Vivian Mary , Capella Márcia Alves Marques , Neto Vivaldo Moura , de Freitas Marta Sampaio , Geracitano Laura Alicia , Monserrat José María , Trindade Gilma Santos
Published: May 2007

Multidrug resistance (MDR) is an obstacle in cancer treatment. An understanding of how tumoral cells react to oxidants can help us elucidate the cellular mechanism involved in resistance. Microcystins are cyanobacteria hepatotoxins known to generate oxidative stress. The aim of this study was to compare the sensitivity to microcystins of human tumoral cell lines with (Lucena) and without (K562) MDR phenotype. Endpoints analyzed were effective microcystins concentration to 50% of exposed cells (EC50), antioxidant enzyme activity, lipid peroxidation, DNA damage, reactive oxygen species (ROS) concentration, and tubulin content. Lucena were more resistant and showed lower DNA damage than K562 cells (P < 0.05). Although microcystins did not alter catalase activity, a higher mean value was observed in Lucena than in K562 cells. Lucena cells also showed lower ROS concentration and higher tubulin content. The higher metabolism associated with the MDR phenotype should increase ROS concentration and make for an improved antioxidant defense against the toxic effects of microcystins.
Histamine H4 receptor expression is elevated in human nasal polyp tissue
Authors: Jókúti Adrienn , Hellinger Éva , Hellinger Andrea , Darvas Zsuzsa , Falus András , Thurmond Robin L. , Hirschberg Andor
Published: May 2007

Altered histamine metabolism is thought to be involved in the pathomechanism of nasal polyposis characterized by local eosinophil infiltration. The present study was performed to determine whether histamine receptors play a role in the effect of histamine in nasal polyp tissue. The findings suggest that the expression of H1 and H4 receptors is elevated in polyp tissue (p = 0.045; p < 0.001), while the level of H2 and H3 receptors is not increased significantly. The elevation of H1 and H4 receptors' expression may indicate that the histamine related mechanisms are preferentially mediated through H1 and H4 histamine receptors in the polyp tissue. Simultaneously with increased H4 receptor expression, the concentration of eosinophil cationic protein (ECP) was increased significantly in polyp tissue (p = 0.002). One may speculate that the H4 receptor mediated histamine effects have a role in eosinophil accumulation and activation in inflammatory diseases of the nasal and paranasal sinus mucosa, such as nasal polyposis.
Caspase‐3‐mediated cleavage of Akt: Involvement of non‐consensus sites and influence of phosphorylation
Authors: Jahani-Asl Arezu , Basak Ajoy , Tsang Benjamin K.
Published: May 2007

Here, we show for the first time that Akt1 is cleaved in vitro at the caspase‐3 consensus site DQDD456
↓ SM. Our data suggest QEEE116
↓ E117
↓ MD, EEMD119↓, TPPD453
↓ QD and DAKE398
↓ IM as novel non‐consensus caspase‐3 cleavage sites. More importantly, we demonstrate that phosphorylation of Akt1 modulates its cleavage in a site‐specific manner: Resistance to cleavage at site DAKE398 (within the kinase domain) in response to phosphorylation suggests a possible mechanism by which the anti‐apoptotic role of Akt1 is regulated. Our result is important in biological models which rely on Akt1 for cell survival.
Comparative Analysis of Eubacterial DNA Polymerase III Alpha Subunits
Authors: Zhao Xiao-Qian , Hu Jian-Fei , Yu Jun
Published: May 2007

DNA polymerase III is one of the five eubacterial DNA polymerases that is responsible for the replication of DNA duplex. Among the ten subunits of the DNA polymerase III core enzyme, the alpha subunit catalyzes the reaction for polymerizing both DNA strands. In this study, we extracted genomic sequences of the alpha subunit from 159 sequenced eubacterial genomes, and carried out sequence-based phylogenetic and structural analyses. We found that all eubacterial genomes have one or more alpha subunits, which form either homodimers or heterodimers. Phylogenetic and domain structural analyses as well as copy number variations of the alpha subunit in each bacterium indicate the classification of alpha subunit into four basic groups: polC, dnaE1, dnaE2, and dnaE3. This classification is of essence in genome composition analysis. We also consolidated the naming convention to avoid further confusion in gene annotations.
Glucose homeostasis remains altered by acute caffeine ingestion following 2 weeks of daily caffeine consumption in previously non-caffeine-consuming males
Authors: Dekker Mark J. , Gusba Jenny E. , Robinson Lindsay E. , Graham Terry E.
Published: May 2007

Acute caffeine ingestion increases serum NEFA and plasma adrenaline and decreases insulin sensitivity. Although frequently suggested, it is not known if a tolerance to these alterations in glucose homeostasis is developed in habitual caffeine consumers. Our objective was to determine whether acute caffeine ingestion continued to alter insulin, glucose, NEFA and adrenaline during an oral glucose tolerance test (OGTT) following 14 d of caffeine consumption. Twelve caffeine-naive young males underwent four OGTTs over a 4-week period. Subjects ingested a gelatin-filled placebo (PLA) capsule on the first trial day and 5 mg caffeine/kg body weight on the remaining three trial days (day 0, day 7, day 14) before a 2 h OGTT. Following day 0 and day 7, subjects were given six dosages of 5 mg caffeine/kg to consume per d between trials. Serum insulin and blood glucose area under the curve (AUC) were significantly elevated (P < 0·05) v. PLA on day 0 (36 and 103 %, respectively) and were not different from PLA on day 7. On day 14, insulin AUC was 29 % greater than PLA (P < 0·05), and glucose was greater (P < 0·05) during the first hour, although the 50 % elevation in glucose AUC was not different from PLA. Before the OGTT, caffeine resulted in greater (P < 0·05) serum NEFA and plasma adrenaline concentrations in all three caffeine trials, but both NEFA and adrenaline concentrations were decreased (P < 0·05) on day 14 v. day 0. Although 14 d of caffeine consumption by previously caffeine-naive subjects reduced its impact on glucose homeostasis, carbohydrate metabolism remained disrupted.
Gonadectomy and high dietary fat but not high dietary carbohydrate induce gains in body weight and fat of domestic cats
Authors: Backus Robert C. , Cave Nick J. , Keisler Duane H.
Published: May 2007

A high concentration of dietary carbohydrate is suggested to increase the risk of obesity and diabetes mellitus in domestic cats. To evaluate this, food intake, body weight, fat mass and circulating adiposity-related factors were determined in twenty-four sexually mature (9–12 months) cats assigned to four six-cat dietary groups balanced for body weight and sex. The effect of dietary fat in exchange for carbohydrate at 9, 25, 44 and 64 % of metabolisable energy (ME) in a purified diet of constant protein:ME ratio was studied 13 weeks before and 17 weeks after gonadectomy (GX). Body weight did not significantly change among the cats before GX except for an increase of 17 (sem5) % in cats given the highest-fat diet. Following GX, all groups gained body weight, and body fat mass was positively correlated (r0·50;P < 0·04) with dietary fat percentage. Post-GX weight gains were much greater for females (+39 (sem5) %) than males (+10 (sem4) %). Plasma ghrelin concentration negatively correlated (P < 0·02) with dietary fat percentage and, before GX, was greater (P < 0·05) in females than males. Plasma insulin concentration increased with weight gain induced by high dietary fat. Plasma glucose, TAG and leptin concentrations were not affected by dietary fat percentage, GX or weight gain. These data provide evidence that in cats, high dietary fat, but not carbohydrate, induces weight gain and a congruent increase in insulin, while GX increases sensitivity to weight gain induced by dietary fat.
Maternal low-protein diet during lactation programmes body composition and glucose homeostasis in the adult rat offspring
Authors: Fagundes A. T. S. , Moura E. G. , Passos M. C. F. , Oliveira E. , Toste F. P. , Bonomo I. T. , Trevenzoli I. H. , Garcia R. M. G. , Lisboa P. C.
Published: May 2007

Previously we have reported that maternal malnutrition during lactation programmes body weight and thyroid function in the adult offspring. In the present study we evaluated the effect of maternal protein restriction during lactation upon body composition and hormones related to glucose homeostasis in adult rats. During lactation, Wistar lactating rats and their pups were divided into two experimental groups: control (fed a normal diet; 23 % protein) and protein-restricted (PR; fed a diet containing 8 % protein). At weaning, offspring received a normal diet until they were 180 d old. Body weight (BW) and food intake were monitored. Serum, adrenal glands, visceral fat mass (VFM) and carcasses were collected. PR rats showed lower BW ( − 13 %;P < 0·05), VFM ( − 33 %;P < 0·05), total body fat ( − 33 %;P < 0·05), serum glucose ( − 7 %;P < 0·05), serum insulin ( − 26 %,P < 0·05), homeostasis model assessment index ( − 20 %), but higher total adrenal catecholamine content (+90 %;P < 0·05) and serum corticosterone concentration (+51 %;P < 0·05). No change was observed in food intake, protein mass or total body water. The lower BW of PR rats is due to a reduction of white fat tissue, probably caused by an increase in lipolysis or impairment of lipogenesis; both effects could be related to higher catecholaminergic status, as well as to hypoinsulinaemia. To conclude, changes in key hormones which control intermediary metabolism are programmed by maternal protein restriction during lactation, resulting in BW alterations in adult rats.
Malleostapedotomy in tympanosclerosis patients
Authors: Magliulo G , Celebrini A , Cuiuli G , Parrotto D , Re M
Published: May 2007

Objectives:

To present our personal experience of a series of 10 patients suffering from tympanosclerosis with functional blocking of the stapes or footplate, who underwent malleostapedotomy surgery. The criteria for patient selection for this type of operation, and its results and complications, are discussed.

Methods:

Prospective study.

Results:

Incus and malleus dysfunction was observed in 70 per cent of cases, either alone or combined with fixation of the stapes. The post-operative hearing results were considered to be satisfactory (i.e. within 20 dB) in 80 per cent of cases. Only one patient had sensorineural hearing loss over 10 dB.

Conclusions:

Malleostapedotomy has proved its practicability in the treatment of patients with fixed footplate or stapes complicated by ankylosis of the incudomalleolar joint. This procedure can be considered a further, valid technique within the otologist's surgical armamentarium.
Islam, Empire and Makassarese historiography in the reign of Sultan Ala'uddin (1593–1639)
Authors: Cummings William
Published: May 2007

During the reign of Sultan Ala'uddin (r. 1593–1639), the Makassarese of Gowa and Talloq initiated a new form of historical writing known as lontaraq bilang. This article argues that this genre represents an Islamic form of historical writing that simultaneously integrated distant places and events within the structure of Makassarese history and Makassarese people and practices within the umma and the structure of Islamic history. Examining this islamisation of history writing yields new insight into premodern Makassarese notions of empire, social change, and religious identity. Lontaraq bilang are an important source of insight into how Makassarese grappled with what it meant to be Muslim and how processes of islamisation were transforming (or should ideally transform) their society.
The Cultivation System (1830–1870) and its private entrepreneurs on colonial Java
Authors: Bosma Ulbe
Published: May 2007

Ever since the interregnum from 1811 to 1816 of Lieutenant Governor General Stamford Raffles, British trading interests had been firmly established in colonial Indonesia. The implementation of the Cultivation System in 1830 on Java by the Dutch colonial government was an attempt to bring this potentially rich colony under Dutch economic control, but it is usually considered a departure from the principles of economic liberalism and a phase during which private entrepreneurs were barred from the emerging plantation economy. However, on the basis of census data and immigration records, and with reference to recent literature on the development of the nineteenth-century sugar industry, this article argues that British trading houses present on Java in the early nineteenth century continued to play an important role in the development of the production there of tropical goods, and that the emerging plantation economy attracted a modest influx of technicians and employees from various European nations. This article proposes to consider the Cultivation System and private enterprise not as mutually exclusive, but as complementary in making the cane sugar industry of Java the second largest in the world after that of Cuba.
Contending views and conflicts over land In Vietnam's Red River Delta
Authors: Van Suu Nguyen
Published: May 2007

This study offers an approach about the nature of peasants and the reasons for their political actions. It examines the views of different parties towards the question on how land should be owned, managed, used, by whom, for whose benefits, and uncovers as well as explains the resulting conflicts over land rights in the Red River Delta since decollectivisation. It postulates that the contending views among parties over decision-making, distribution, and holding of land rights, create dynamics for conflicts, which take place under the form of public resistance, in a number of communities.
Paul Scott's Later Novels: The Unknown Indian
Authors: GOONETILLEKE D. C. R. A.
Published: May 2007

The Raj Quartet is a novel in which Scott has transmuted contemporary history into fiction—the many forces at work in India over a period of five years, from the ‘Quit India’ motion of the Congress Committee in 1942 to the eve of Independence and Partition. Deeper than Scott's interest in history and politics, however, is his aim to probe the nature of human destiny, conveying a philosophy of life that shows man's destiny and moral sense sometimes at variance. He also focuses an ordinary human point of view on the world around him, valuing integrity and decency. Staying On is not a political or historical novel, although its background has political implications. It focuses mainly on problems relating to personal destiny. Scott's later novels constitute a major achievement in colonial, indeed, all, literature.
Chemical abundances of secondary stars in low mass X-ray binaries
Authors: Hernández Jonay I. González , Rebolo Rafael , Israelian Garik
Published: May 2007

Low mass X-ray binaries (LMXBs) offer us an unique opportunity to study the formation processes of compact objects. Secondary stars orbiting around either a black hole or a neutron star could have captured a significant amount of the ejected matter in the supernova explosions that most likely originated the compact objects. The detailed chemical analysis of these companions can provide valuable information on the parameters involved in the supernova explosion such us the mass cut, the amount of fall-back matter, possible mixing processes, and the energy and the symmetry of the explosion. In addition, this analysis can help us to find out the birth place of the binary system. We have measured element abundances of secondary stars in the LMXBs A0620–00, Cen X-4, XTE J1118+480 and Nova Sco 94. We find solar or above solar metalicity for all these systems, what appears to be independent on their locations with respect to the Galactic plane. A comparison of the observed abundances with yields from different supernova explosion together with the kinematic properties of these systems suggest a supernova origin for the compact objects in all of them except for A0620–00, for which a direct collapse cannot be discarded.
Uncertainties of the masses of black holes and Eddington ratios in AGN
Authors: Collin Suzy
Published: May 2007

Black hole masses in Active Galactic Nuclei have been determined in 35 objects through reverberation mapping of the emission line region. I mention some uncertainties of the method, such as the “scale factor” relating the Virial Product to the mass, which depends on the unknown structure and dynamics of the Broad Line Region.

When the black hole masses are estimated indirectly using the empirical size-luminosity relation deduced from this method, the uncertainties can be larger, especially when the relation is extrapolated to high and low masses and/or luminosities. In particular they lead to Eddington ratiosof the order of unity in samples of Narrow Line Seyfert 1. As the optical-UV luminosity is provided by the accretion disk, the accretion rates can be determined and are found to be much larger than the Eddington rates.

So, accretion must be performed at a super-critical rate through a slim disk, resulting in rapid growth of the black holes. The alternative is that the mass determination is wrong at this limit.
Accretion of stellar winds onto Sgr A*
Authors: Cuadra Jorge , Nayakshin Sergei
Published: May 2007

We report a 3-dimensional numerical study of the accretion of stellar winds onto Sgr A*, the super-massive black hole at the centre of our Galaxy. Compared with previous investigations, we allow the stars to be on realistic orbits, include the recently discovered slow wind sources, and allow for optically thin radiative cooling. We first show the strong influence of the stellar dynamics on the accretion onto the central black hole. We then present more realistic simulations of Sgr A* accretion and find that the slow winds shock and rapidly cool, forming cold gas clumps and filaments that coexist with the hot X-ray emitting gas. The accretion rate in this case is highly variable on time-scales of tens to hundreds of years. Such variability can in principle lead to a strongly non-linear response through accretion flow physics not resolved here, making Sgr A* an important energy source for the Galactic centre.
Short-term variability of Sgr A*
Authors: Morris M. R. , Hornstein S. D. , Ghez A. M. , Lu J. R. , Matthews K. , Baganoff F. K.
Published: May 2007

Observations of Sgr A* over the past 4 years with the Keck Telescope in the near-infrared, coupled with millimeter and submillimeter observations, show that the 3.7×106M⊙Galactic Black Hole, Sagittarius A*, displays continuous variability at all these wavelengths, with the variability power concentrated on characteristic time scales of a few hours, and with a variability fraction that increases with wavelength. We review the observations indicating that the few-hour time scale for variability is reproduced at all accessible wavelengths. Interpreted as a dynamical time, this time scale corresponds to a radial distance of 2 AU, or ∼25 Schwarzschild radii. Searches for quasi-periodicities in the near-infrared data from the Keck Telescope have so far been negative. One interpretation of the character of these variations is that they result from a recurring disk instability, rather than from variations in the mass accretion rate flowing through the outer boundary of the emission region. However, neither a variable accretion rate nor a mechanism associated with a jet can presently be ruled out.
Ultra-luminous X-ray sources: X-ray binaries in a high/hard state?
Authors: Kuncic Z. , Soria R. , Hung C. K. , Freeland M. C. , Bicknell G. V.
Published: May 2007

We examine the possibility that Ultraluminous X-ray sources (ULXs) represent the extreme end of the black hole X-ray binary (XRB) population. Based on their X-ray properties, we suggest that ULXs are persistently in a high/hard spectral state and we propose a new disk–jet model that can accomodate both a high accretion rate and a hard X-ray spectrum. Our model predicts that the modified disk emission can be substantially softer than that predicted by a standard disk as a result of jet cooling and this may explain the unusually soft components that are sometimes present in the spectra of bright ULXs. We also show that relativistic beaming of jet emission can indeed account for the high X-ray luminosities of ULXs, but strong beaming produces hard X-ray spectra that are inconsistent with observations. We predict the beamed synchrotron radio emission should have a flat spectrum with a flux density ≲0.01 mJy.
Dipole–vortex structure of the obscuring tori in active galactic nuclei
Authors: Bannikova Elena Yu. , Kontorovich Victor M.
Published: May 2007

A “matrjoshka” scheme for obscuring vortex torus structure is proposed, which could help to explain the AGN radiation flares, variability and evolution.
Optical, ultraviolet and X-ray analysis of the black hole candidate BG Geminorum
Authors: Elebert P. , Callanan P. J. , Russell L. , Shaw S. E.
Published: May 2007

We present the first high resolution optical spectrum of the black hole candidate BG Geminorum, as well as UV spectroscopy from the Hubble Space Telescope, and X-ray data from INTEGRAL. The UV spectra suggest the presence of material in BG Gem with velocities possibly as high as ∼1000 km s−1, suggesting an origin at a distance of ∼0.7 R⊙ from a 3.5 M⊙ object; if real, this would be strong evidence that the primary in BG Gem is indeed a black hole. In contrast, the upper limit provided by the INTEGRAL data gives a maximum X-ray luminosity of only ∼0.1 of the Eddington luminosity.
Uncertainty principle for the entropy of black holes, de Sitter and Rindler spaces
Authors: Hara Tetsuya , Sakai Keita , Kunitomo Shuhei , Kajiura Daigo
Published: May 2007

By a simple physical consideration and uncertain principle, we derive that temperature is proportional to the surface gravity and entropy is proportional to the surface area of the black hole. We apply the same consideration to de Sitter space and estimate the temperature and entropy of the space, then we deduce that the entropy is proportional to the boundary surface area. By the sameconsideration, we estimate the temperature and entropy in the uniformly accelerated system (Rindler space). The cases in higher dimensions are considered.
Intensity and polarization light-curves from radiatively-driven clouds
Authors: Horák Jiří , Karas Vladimír
Published: May 2007

We study linear polarization from scattering of light on a cloud of relativistic electrons. We assume that the cloud is hovering above an accretion disc, or it is in an accelerated motion underthe combined influence of the radiation and gravitational fields near an accreting black hole. Atfirst we derive simple and general analytical formulae for the Stokes parameters. These formulae are then used in calculations of the temporal evolution of the observed signal.

We find that higher-order images can significantly enhance the observed flux. Possible targets where the effect should be searched are accreting super-massive black holes and Galactic microquasars exhibiting episodic accretion/ejection events.
Fe K line profile in PG quasars: the averaged shape and Eddington ratio dependence
Authors: Inoue H. , Terashima Y. , Ho L. C.
Published: May 2007

Fe K emission line is a powerful probe of the inner part of an accretion disk. We analyze X-ray spectra of 43 Palomar-Green (PG) quasars taken from Boroson & Green (1992) observed with XMM-Newton and make an averaged Fe K line profile. We study the Eddington ratio dependence of the Fe K line profile. The width of the Fe line becomes broader (σ=0.1 to 0.7 keV) and its peak energy becomes higher (6.4 to 6.8 keV) as the Eddington ratio gets larger.

These results indicate that the physical state of the accretion disk, such as the geometrical structure and/or ionization state, changes with the Eddington ratio.
The capture of main sequence stars and giant stars by a massive black hole
Authors: Lu Y. , Huang Y. F , Zheng Z. , Zhang S. N.
Published: May 2007

Since the mass-radius relation is quite different for a main sequence (MS) star and a giant (G) star, we find that the radiation efficiencies in the star capture processes by a black hole (BH) are also very different. This may provide a useful way to distinguish the capture of MS and G stars. Comparing with observations of the very high energy (VHE) gamma-ray emissions, we argue the event that triggers the gamma-ray emission in the energy range 4–40 TeV should be a G star capture. On the other hand, the capture of MS stars by the massive BH is required when the measured spectrum of VHE gamma-rays extends from 109 to 1015 eV.
Low-frequency, one-armed oscillations in black hole accretion flows obtained from direct 3D MHD simulations
Authors: Machida Mami , Matsumoto Ryoji
Published: May 2007

We present the results of global 3D MHD simulations of optically thin black hole accretion flows. The initial disk is embedded in a low density, spherical, isothermal halo and threaded by weak (β ≡ Pgas/Pmag = 100) toroidal magnetic field. General relativistic effects are simulated by using the pseudo-Newtonian potential. When the Maxwell stress in the innermost region of the disk is reduced due to the loss of magnetic flux or by decrease of disk temperature, inner torus is created around 4 – 10rs. We found that in such an inner torus, one-armed (m = 1) density enhancement grows and that the inner torus oscillates quasi-periodically. The oscillation period is about 0.1s when we assume a 10M⊙ black hole. This frequency agrees with the low-frequency QPOs observed in low/hard state of black hole candidates. The disk ejects winds whose opening angle is about 30 degree. The maximum velocity of the wind is about 0.05c.
Masses of radiation pressure supported stars in extreme relativistic realm
Authors: Mitra Abhas
Published: May 2007

We discuss that in the extreme relativistic limit, i.e., when z ≫ 1, where z is the surface gravitational redshift, there could be radiation pressure supported and dominated stars with arbitrary gravitational mass, high or low. Such objects are called Eternally Collapsing Objects (ECOs). ECOs are practically as compact as Schwarzschild black holes (BH) and, observationally, are likely to be mistaken as BHs. Further since any object undergoing continued collapse must first become an ECO before becoming a true BH state characterized by M = 0, the observed BH Candidates are ECOs.
Radiation spectra from MHD simulations of low angular momentum flows
Authors: Moscibrodzka Monika A. , Proga Daniel , Czerny Bożena , Siemiginowska Aneta
Published: May 2007

We perform Monte Carlo calculation to determine the radiation spectra from magnetized, low angular momentum accretion flow. Magneto-hydrodynamical simulation (with angular momentum parameter lambda of about 2 Rg c) was performed by Proga & Begelman 2003. Because simulation neglect radiative cooling, we compute electron temperature separately, including ohmic heating, parametrized with small δ coefficient, ion-electron coupling, radiative cooling and advection. Radiation spectra are obtained taking into account, thermal synchrotron and bremsstrahlung radiation, self absorption and Comptonization processes.

We show which parts of the flow are responsible for characteristic spectral features and how the spectrum changes in different accretion states. We compare our results with Galactic Center black hole radiation spectra, where low angular momentum accretion is suggested. Accretion state changes seems to be a promising model for the flaring behavior of Galactic Center black hole. We also show the radiation intensity maps in radio and X-rays energy band for viewing angle i = 90°.
Can gravitational microlensing be used to probe geometry of a massive black-hole?
Authors: Popović Luka Č , Jovanović Predrag
Published: May 2007

Here we discuss the possibility to use gravitational microlensing in order to probe the geometry around a massive black hole. Taking into account that lensed quasars are emitting X-rays which come from the heart of these objects, we investigated the influence of microlensing on the Fe Kα line shape originated in Schwarzschild and Kerr metrics.
Exact solutions for discs around stationary black holes
Authors: Požár N. , Semerák O. , Šácha J. , Žáček M. , Zellerin T.
Published: May 2007

Black holes surrounded by axisymmetric structures prosper in some of the most interesting sources in the universe. However, a consistent exact description of the gravitational field of these systems is still lacking. In a static case, the task reduces to Laplace equation and the fields of multiple sources follow by mere superposition. In a rotating case, non-linearity of the Einstein equations resists simple grasp, but even then the theory of completely integrable systems seems to verge on satisfactory solutions. It seeks them in terms of θ-functions on special manifolds connected – symptomatically – with the names of Riemann and Hilbert.
The X-ray–radio association in RATAN and RXTE monitoring of microquasar GRS 1915+105
Authors: Trushkin S. A. , Kotani T. , Kawai N. , Namiki M. , Fabrika S. N.
Published: May 2007

In the daily RATAN-600 monitoring of the radio variability of the microquasar GRS1915+105 we detected a clear correlation of the flaring radio emission and X-rays “spikes” at 2–12 keV emission (1–2 Crab) detected with RXTE (ASM data) during nine bright (200–600 mJy) radio flares in October 2005. The spectra of these flares in maximum were optically thick at ν<2.3 GHz and optically thin at ν≥2.3 GHz. During radio flares the spectra of the X-ray spikes became definitely softer than those of a quiescent radio state. Thus these data indicated transitions from very high/hard states to high/soft ones during which massive ejections are probably happened, and the ejections are detected as the radio flares.
Flaring activity of microquasars from multi-frequency daily monitoring program with RATAN-600 radio telescope
Authors: Trushkin S. A. , Nizhelskij N. A. , Bursov N. N. , Majorova E. K.
Published: May 2007

We report about the multi-frequency (1–30 GHz) daily monitoring of the radio flux variability of the three microquasars: SS433, GRS1915+105 and Cyg X-3 during 2005–2006. After a quiescent radio emission we have detected a drop down of the fluxes (∼20 mJy) from Cyg X-3, a sign of the following bright flare, and indeed a 1 Jy flare was detected on 2 February 2006 after 18 days of quenched radio emission. The daily spectra of the flare in the maximum was found flat from 2 to 110 GHz, using the quasi-simultaneous observations at 109 GHz with the RT45m telescope and the NMA millimeter array of Nobeyama Radio Observatory in Japan. Several bright radio flaring events (1–15 Jy) followed during the state of highly variable and intense 1–12 keV X-ray emission (∼0.5 Crab), monitored in the RXTE ASM program. We discussed various spectral and temporal characteristics of the detected 180 day light curves from three microquasars in comparison with the Rossi XTE ASM data.