bluuebunny/crossref_metadata_2025 huggingface dataset:
'Theirs was a deeper purpose': The Pennsylvania Germans of Ontario and the Craft of the Homemaking Myth
Authors: Fair Ross
Published: January 2007

The article analyses the immigrant narrative of the Pennsylvania Germans who settled Upper Canada between the 1780s and the 1830s, using Orm Øverland's framework of a 'homemaking myth.' The Pennsylvania-German myth first appeared in the 1890s and claimed a share of the United Empire Loyalists' foundational myth, drawing upon its themes of loyalty and sacrifice. Later authors modified and amplified these themes to distance the Pennsylvania Germans from the Germans whom Canadians were fighting in the First World War. Soon after the conflict, the Historic Sites and Monuments Board of Canada recognized the Pennsylvania-German migration to Upper Canada as an event of national significance, highlighting the success of the homemaking myth's message. Throughout the rest of the twentieth century, authors contin ued to promote the theme of loyalty, but with the dawn of official multiculturalism in Canada the Pennsylvania Germans regained their Germanness, becoming founders of the German-Canadian community. The article suggests that the historical analysis of other immigrant groups in Canada may benefit from the interpretive framework provided by the homemaking myth, and argues that the Pennsylvania-German narrative highlights a need to rethink how local and amateur histories contribute to a shared sense of Canadian identity. Dans l'article, on analyse les récits d'Allemands de Pennsylvanie ayant immigré au Haut-Canada entre les années 1780 et les années 1830, Ã  l'aide du modèle d'Orm Øverland d'un Â« homemaking myth Â». Le mythe des Allemands de Pennsylvanie est apparu pour la première fois au cours des années 1890 et s'est approprié une partie du mythe lié Ã  la fondation des Loyalistes de l'Empire-Uni, en empruntant les thèmes de la loyauté et du sacrifice. Par la suite, les auteurs ont modifié et amplifié ces thèmes pour distinguer les Allemands de Pennsylvanie des Allemands que les Canadiens combattaient durant la Première Guerre mondiale. Peu après le conflit, la Commission des lieux et monuments historiques du Canada a reconnu que la migration des Allemands de Pennsylvanie vers le Haut-Canada a été un événement ayant une portée nationale, ce qui met en évidence le succès lié au message du homemaking myth. Pendant le reste du XXe siècle, les auteurs ont continué de promouvoir le thème de la loyauté. Toutefois, avec la montée du multiculturalisme officiel au Canada, les Allemands de Pennsylvanie sont redevenus Allemands, pour devenir les fondateurs de la communauté germano-canadienne. L'article montre que le modèle interprétatif du homemaking myth peut être utile dans l'étude d'autres groupes immigrants au Canada. De plus, on soutient que les récits des Allemands de Pennsylvanie soulignent Ã  quel point il est nécessaire de revoir comment les histoires locales et amateurs contribuent au sentiment général d'identité canadienne.
The impact of parental death on school outcomes: Longitudinal evidence from South Africa
Authors: Case Anne , Ardington Cally
Published: January 2007

We analyze longitudinal data from a demographic surveillance area (DSA) in KwaZulu-Natal to examine the impact of parental death on children’s outcomes. The results show significant differences in the impact of mothers’ and fathers’ deaths. The loss of a child’s mother is a strong predictor of poor schooling outcomes. Maternal orphans are significantly less likely to be enrolled in school and have completed significantly fewer years of schooling, conditional on age, than children whose mothers are alive. Less money is spent on maternal orphans’ educations, on average, conditional on enrollment. Moreover, children whose mothers have died appear to be at an educational disadvantage when compared with non-orphaned children with whom they live. We use the timing of mothers’ deaths relative to children’s educational shortfalls to argue that mothers’ deaths have a causal effect on children’s educations. The loss of a child’s father is a significant correlate of poor household socioeconomic status. However, the death of a father between waves of the survey has no significant effect on subsequent asset ownership. Evidence from the South African 2001 Census suggests that the estimated effects of maternal deaths on children’s outcomes in the Africa Centre DSA reflect the reality for orphans throughout South Africa.
Gentilshommes campagnards de la nouvelle France, XVIIeâXIXe siecle: Une autre seigneurie laurentienne?
Authors: Grenier Benoit
Published: January 2007

Although they were a minority among seigneurs in the St. Lawrence Valley, resident seigneurs maintained a much more "intimate" relationship to their community than those who were absent from their fiefs. This article, which examines ten resident seigneurial families from their beginnings in the seventeenth century to the abolition of the Canadian seigneurial regime in the nineteenth, discovers harmonious social relations between the two central actors of the preindustrial rural world: the seigneur and the habitant. While the historiography of the last several decades insisted on the "feudal" and binding character of the Canadian seigneurial system, the study of resident seigneurs suggests a different understanding of seigneurial relationships. Seigneurial godfathers and godmothers, shared family or collective festivities, and beneficent actions of seigneurs are evidence for a kinder, gentler Canadian seigneurie in which the time of arrival of the seigneurial family and the social origin of the seigneur (noble or commoner) were important factors. Resident seigneurs thus call into question the oppressive character of the regime, despite the existence of various conflicts.
The History of Africanization and the Africanization of History
Authors: Brizuela-García Esperanza
Published: January 2007

The idea of Africanization is arguably one of the most important and prevalent in African historiography and African studies. I first encountered this notion some eight years ago when I started graduate school. With a background in Mexican and Latin American history, I found it necessary to immerse myself in the historiography of Africa. It was in this process that I encountered the idea of Africanization. It was not always identified in this manner, but it was clear that historians were, in one way or another, articulating a concern about how “African” was African history.

The objective of this paper is to examine the history of Africanization in African historiography. It departs from two basic premises. First, the issues that come with the idea of Africanization are more pronounced in the field of African history. When compared to other fields, such as Latin American history, this indigenizing of history is not given nearly so much attention. Second, the idea that African history needs to be Africanized has been taken for granted, and has not been critically examined. Here I will contend that the historical conditions that have framed the emergence and development of African historiography have made it necessary to emphasize the issue of Africanization. I will also argue that those conditions have changed in the past fifty years, and that the questions raised in the quest to Africanize history should be redefined in view of the new challenges for African history and of historiography at large.
Appropriate Inhibition of Orexigenic Hypothalamic Arcuate Nucleus Neurons Independently of Leptin Receptor/STAT3 Signaling
Authors: Münzberg Heike , Jobst Erin E. , Bates Sarah H. , Jones Justin , Villanueva Eneida , Leshan Rebecca , Björnholm Marie , Elmquist Joel , Sleeman Mark , Cowley Michael A. , Myers Martin G.
Published: January 2007

Leptin directly suppresses the activity of orexigenic neurons in the hypothalamic arcuate nucleus (ARC). We examined c-Fos-like immunoreactivity (CFLIR) as a marker of ARC neuronal activity indb/dbmice devoid of the signaling form of the leptin receptor (LRb) ands/smice that express LRbS1138[which is defective for STAT3 (signal transducer and activator of transcription) signaling]. Bothdb/dbands/sanimals are hyperphagic and obese. This analysis revealed that CFLIR in agouti related peptide-expressing orexigenic ARC neurons is basally elevated indb/dbbut nots/smice. Consistent with these observations, electrophysiologic evaluation of a small number of neurons ins/sanimals suggested that leptin appropriately suppresses the frequency of IPSCs on ARC proopiomelanocortin (POMC) neurons that are mediated by the release of GABA from orexigenic ARC neurons. CFLIR in POMC neurons ofs/smice was also increased compared withdb/dbanimals. Thus, these data suggest that, although LRb→STAT3 signaling is crucial for the regulation of feeding, it is not required for the acute or chronic regulation of orexigenic ARC neurons, and the activation of STAT3-mediated transcription by leptin is not required for the appropriate development of leptin responsiveness in these neurons.
DISC1 Regulates Neurotrophin-Induced Axon Elongation via Interaction with Grb2
Authors: Shinoda Tomoyasu , Taya Shinichiro , Tsuboi Daisuke , Hikita Takao , Matsuzawa Reiko , Kuroda Setsuko , Iwamatsu Akihiro , Kaibuchi Kozo
Published: January 2007

Disrupted-in-Schizophrenia-1(DISC1) is a candidate gene for susceptibility of schizophrenia. In the accompanying paper (Taya et al., 2006), we report that DISC1 acts as a linker between Kinesin-1 and DISC1-interacting molecules, such as NudE-like, lissencephaly-1, and 14-3-3ε. Here we identified growth factor receptor bound protein 2 (Grb2) as a novel DISC1-interacting molecule. Grb2 acts as an adaptor molecule that links receptor tyrosine kinases and the Ras–extracellular signal-regulated kinase (ERK) pathway. DISC1 formed a ternary complex with Grb2 and kinesin heavy chain KIF5A of Kinesin-1. In cultured rat hippocampal neurons, both DISC1 and Grb2 partially colocalized at the distal part of axons. Knockdown of DISC1 or kinesin light chains of Kinesin-1 by RNA interference inhibited the accumulation of Grb2 from the distal part of axons. Knockdown of DISC1 also inhibited the neurotrophin-3 (NT-3)-induced phosphorylation of ERK-1/2 at the distal part of axons and inhibited NT-3-induced axon elongation. These results suggest that DISC1 is required for NT-3-induced axon elongation and ERK activation at the distal part of axons by recruiting Grb2 to axonal tips.
Effect of crop production factors on the yield and yield stability of maize (Zea mays L.) hybrids
Authors: Z. Berzsenyi Z. , Dang Q. L.
Published: January 2007

The effect of sowing date, N fertiliser rate, plant density and genotype
on the yield stability of maize was analysed using 15-year data from a
5×4×5-factorial sowing date experiment, 35-year data from a two-factorial N
fertilisation experiment and 25-year data from a two-factorial plant density
experiment. Stability analysis on the experimental treatments was carried out
using the variance and regression methods. Among the variance parameters, the
ecovalence (W), the stability variance (σ²) and the yield stability
(YS) were calculated. Based on the data of the sowing date experiment the
optimum sowing date (Apr. 24) or sowing ten days later (May 5) were found to be
the most stable due to the low, non-significant values of the variance
parameters and the values close to unity for the regression coefficients (b).
Although early sowing (Apr. 14) led to a significantly higher yield than late
sowing, the yield stability was poorer for early sowing. In the long-term N
fertilisation experiment the variance parameters indicated the least yield
fluctuation at N rates of 80 and 160 kg ha-1, though the yield
stability (YS) parameter for the 240 kg ha-1 N rate was also above-average.
Regression analysis showed that the yield level and yield stability were the
same in all environments for the 160 and 240 kg ha-1 N rates. The
stability of the 80 kg ha-1 N rate was similar, but the yield level
was approx. 1.3 t ha-1 lower. The yield stability of the plant
density response of the maize hybrids was different in each maturity group (FAO
number). The stable plant density range was broadest (50-90 thousand plants ha-1)
in the FAO 200-299 group. As the vegetation period lengthened the stable plant
density range narrowed and shifted towards lower plant densities (for the FAO
400-499 and FAO 500-599 maturity groups: 50-70 thousand plants ha-1).
The variance and regression parameters of stability analysis both contributed
to the characterisation of the stability of the genotypes and cropping systems
investigated. It can be concluded from the results that high yields and yield
stability are not necessarily mutually exclusive.
Complexation Properties of the Di‐, Tri‐, and Tetraacetate Derivatives of Bis(aminomethyl)phosphinic Acid
Authors: Tircsó Gyula , Bényei Attila , Király Róbert , Lázár István , Pál Róbert , Brücher Ernő
Published: January 2007

Four ligands, which can be considered as di‐ [both symmetric (L1) and asymmetric (L2)], tri‐ (L3), and tetraacetate (L4) derivatives of bis(aminomethyl)phosphinic acid (L0) have been synthesized and their complexation equilibria involving Mg2+, Ca2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+ have been studied by pH potentiometry. The first two protonation constants of the ligands are lower than those of the analogous diaminopolycarboxylates due to the electron‐withdrawing effect of the phosphinate group. The asymmetric ligands L2 and L3 and their complexes are protonated first at the primary (NH2) and secondary (NH) amine groups, respectively. The ligands L0, L1, L2, and L3 form the species ML, MLH, ML2, and ML2H whereas heptadentate L4 forms very stable ML complexes, protonated (MLH and MLH2) species and, unlike the other ligands, it also forms dinuclear M2L complexes. The stability constants of the complexes of L0, L1, L2, and L3 are generally lower, while those of the L4 are similar or higher, than those of the analogous diaminocarboxylate derivatives. The phosphinate group is not directly coordinated to the metal ions but may contribute to the stability by increasing the electrostatic interaction, which is significant for the complexes of L4. The 1H NMR spectra of complexes ZnL2, ZnL3, and ZnL4 show an AB multiplet pattern for the protons of the iminodiacetate moiety of the ligands, which indicates the long half‐life of the Zn2+–N bond and the rigid structure of this segment of the complexes. The solid‐state structure of the ligand [H5L3]Cl and complex K[CuL1]·H2O have been determined by X‐ray diffraction techniques. The arrangement of the ligand L1 is square planar around Cu2+ with two nitrogen and carboxylate oxygen donor atoms, although the axial proximity of a carboxylate and a phosphinate oxygen atom in two neighboring molecules results in a distorted octahedral coordination.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Microglia derived from aging mice exhibit an altered inflammatory profile
Authors: Sierra Amanda , Gottfried‐Blackmore Andres C. , McEwen Bruce S. , Bulloch Karen
Published: January 2007

Microglia play a critical role in neurodegenerative diseases and in the brain aging process. Yet, little is known about the functional dynamics of microglia during aging. Thus, using young and aging transgenic mice expressing enhanced‐green fluorescent protein (EGFP) under the promoter of the c‐fms gene for macrophage‐colony stimulating factor receptor, we evaluated invivo‐induced inflammatory responses of EGFP‐expressing microglia sorted by flow cytometry. Aging microglia were characterized by the presence of lipofuscin granules, decreased processes complexity, altered granularity, and increased mRNA expression of both pro‐inflammatory (TNFα, IL‐1β, IL‐6) and anti‐inflammatory (IL‐10, TGFβ1) cytokines. Following lipopolysaccharide (LPS) challenge (1 mg/kg, 3 h), aging microglia exhibit increased basal expression of TNFα, IL‐1β, IL‐6, and IL‐10. Yet, the fold‐over‐basal LPS response remained constant across age, implying that the inflammatory machinery in aging microglia is functional and adjusted to the basal state. Gender differences were not overall observed across the treatments (age, LPS). The low but sustained production of pro‐inflammatory cytokines by aging microglia may have a profound impact in the brain aging process. © 2007 Wiley‐Liss, Inc.
Differential effects of naturally occurring and synthetic organoselenium compounds on biomarkers in androgen responsive and androgen independent human prostate carcinoma cells
Authors: Pinto John T. , Sinha Raghu , Papp Kate , Facompre Nicole D. , Desai Dhimant , El‐Bayoumy Karam
Published: January 2007

Epidemiological studies and clinical trials show that selenium supplementation results in reduction of prostate cancer incidence; however, the form of selenium and mechanisms underlying protection remain largely unknown. Toward this end, we compared the effects of naturally occurring selenomethionine (SM) and Se‐methylselenocysteine (MSC) and synthetic 1,4‐phenylenebis(methylene)selenocyanate (p‐XSC) andp‐xylylbis(methylselenide)p‐XMS) organoselenium compounds in androgen responsive (AR) LNCaP and its androgen independent clone (AI) LNCaP C4‐2 human prostate carcinoma cells on cell growth, secretion of prostate specific antigen (PSA), intracellular redox status and genomic profiles with emphasis on identifying redox sensitive genes. Bothp‐XSC andp‐XMS reduced cell number and total protein concentration compared to control‐treated AR and AI cells, while SM and MSC exhibited no effect on growth of AR and AI cells. SM,p‐XSC andp‐XMS but not MSC inhibited levels of secreted PSA in AR cells. SM, MSC andp‐XMS increased glutathione (GSH) levels in AI LNCaP cells. By contrast, in both cell types, onlyp‐XSC significantly decreased GSH concentrations to <50% of control suggesting either an increase in intracellular oxidative stress or a change in GSH/GSSG ratio. On the basis of RT‐PCR analysis, SM andp‐XSC increasedp53gene expression by 2‐fold in AR cells but not in AI cells and only SM enhanced epidermal growth factor receptor in AR cells. Depending on the structure, organoselenium compounds exhibit differential effects on growth, PSA secretion, oxidative stress and selective gene responses in human prostate cancer cells and suggest the potential of developing novel organoselenium compounds as chemopreventive agents in models of human prostate cancer. © 2006 Wiley‐Liss, Inc.
Regulation of P53 stability in p53 mutated human and mouse hepatoma cells
Authors: Hailfinger Stephan , Jaworski Maike , Marx‐Stoelting Philip , Wanke Ines , Schwarz Michael
Published: January 2007

The tumor suppressor p53 is frequently mutated in cancer. We have investigated the regulation of P53 in p53 wild type mouse hepatoma cells (line 55.1c), in p53 heterozygeously mutated cells (56.1b) and in p53 defective cells (lines 56.1d, 70.4 and HUH7) under various experimental settings. The basal levels of P53 were low in 55.1c cells, but nuclear accumulation occurred upon UV‐irradiation. Similarly, UV‐exposure induced stabilization of P53 in the heterozygeously p53 mutated 56.1b hepatoma cells. By contrast, the 3 hepatoma lines, which lack transcriptionally active P53, demonstrated high basal nuclear concentrations of P53 protein and, unexpectedly, showed loss of P53 upon UV‐irradiation. Expression of p53 mRNA was also decreased in p53 defective cells after 24 hr post UV‐irradiation, which may be linked to induction of apoptosis of the irradiated cells under these conditions. Other stressors like H2O2 also mediated a decrease in P53 concentration in p53 defective cells. This effect occurred at very low concentrations and was already detectable 1–2 hr after exposure of cells. There were no signs of apoptosis of H2O2‐exposed cells at this time point and no significant changes in p53 mRNA or MDM2 level. These unexpected findings indicate a new aspect related to regulation of P53 stability in cells with a defect in the tumor suppressor protein. © 2006 Wiley‐Liss, Inc.
Low adiponectin levels are associated with renal cell carcinoma: A case‐control study
Authors: Spyridopoulos Themistoklis N. , Petridou Eleni Th. , Skalkidou Alkistis , Dessypris Nick , Chrousos George P. , Mantzoros Christos S. , the Obesity and Cancer Oncology Group
Published: January 2007

Adiponectin is a novel endogenous insulin sensitizer, secreted by mature adipocytes. Circulating levels of adiponectin are inversely associated with obesity and insulin resistance. Because obesity is a risk factor for renal cell carcinoma (RCC), we hypothesized that low adiponectin levels are associated with RCC. To evaluate this hypothesis, we conducted a case‐ control study of 70 patients with histologically confirmed RCC and 280 healthy controls matched by gender, age and county of residence. Study subjects were interviewed and blood samples were collected during a 32‐month period in Athens, Greece. Serum adiponectin levels were statistically, significantly and inversely associated with RCC when compared with controls (OR = 0.76, p = 0.05) and this association remained practically unchanged after controlling for BMI; the introduction of waist to hip ratio along with adiponectin in the multiple logistic regression analysis model rendered the association between adiponectin and RCC risk insignificant, indicating that altered levels of adiponectin may mediate the effect of central or intra‐abdominal obesity on RCC. Prospective studies as well as studies exploring underlying mechanisms are needed to fully explore the role of adiponectin in predicting future risk of RCC in humans. © 2006 Wiley‐Liss, Inc.
George Herbert Mead and the Allen controversy at the University of Wisconsin
Authors: Cook Gary A.
Published: January 2007

This essay uses previously unpublished correspondence of George Herbert Mead to tell the story of his involvement in the aftermath of a political dispute that took place at the University of Wisconsin during the years 1914–1915. It seeks thereby to clarify the historical significance of an article he published on this controversy in late 1915. Taken together with relevant information about the educational activities of William H. Allen of the New York Bureau of Municipal Research, Mead's correspondence and article throw helpful light upon his understanding of how an educational survey of a university should proceed; they also show how he went about the task of evaluating a failed attempt at such a survey. © 2007 Wiley Periodicals, Inc.
Retinoic acid and nerve growth factor induce differential regulation of nicotinic acetylcholine receptor subunit expression in SN56 cells
Authors: Nilbratt Mats , Friberg Linda , Mousavi Malahat , Marutle Amelia , Nordberg Agneta
Published: January 2007

Retinoic acid (RA) and nerve growth factor (NGF) have multiple functions in the regulation of neuronal development. In the present study, we characterized the expression of different nicotinic acetylcholine receptor (nAChR) subtypes in the cholinergic SN56 cell line and investigated the roles of RA and NGF in the expression of choline acetyltransferase (ChAT) and different nAChR subtypes. The nAChR agonist [3H]epibatidine was bound to two sites, with apparent affinities of 13 and 380 pM. RT‐PCR analysis revealed expression of α3, α4, α5, α7, β2, and β4 nAChR subunits. RA treatment induced morphological changes, and the mRNA level of ChAT was maximally elevated after 4 days of exposure. The density of [3H]epibatidine binding sites and the mRNA and protein level of the α3 and β2 nAChR subunits were also increased by RA‐induced differentiation. RA down‐regulated the mRNA and protein level of the α4 nAChR subunit, whereas no significant change was observed in the mRNA and protein level of the α7 nAChR subunit. NGF treatment increased the mRNA and protein level of the α3 and β2 nAChR subunits. No morphological effects of NGF were observed, and the mRNA level of ChAT and mRNA and protein level of the α4 and α7 nAChR subunits were not significantly altered. Validation was performed with real‐time RT‐PCR. The present results show that RA and NGF have different effects on the expression of ChAT and the morphology and the expression pattern of different nAChR subunits in cholinergic SN56 cells. © 2006 Wiley‐Liss, Inc.
Observer design for a class of piecewise linear systems
Authors: Lj. Juloski A. , Heemels W. P. M. H. , Weiland S.
Published: January 2007

In this paper we present observer design procedures for a class of bi‐modal piecewise linear systems in both continuous and discrete time. We propose Luenberger‐type observers, and derive sufficient conditions for the observation error dynamics to be globally asymptotically stable, in the case when the system dynamics is continuous over the switching plane. When the dynamics is discontinuous, we derive conditions that guarantee that the relative estimation error with respect to the state of the observed system will be asymptotically small. The presented theory is illustrated with several examples. Copyright © 2007 John Wiley & Sons, Ltd.
The role of collaborative support to promote participation and commitment in software development teams
Authors: de Araujo Renata Mendes , Borges Marcos R. S.
Published: January 2007

This work discusses the use of collaborative technology as an element for extending software process culture within development teams. This discussion starts with the idea that collaboration support comprises an important element for software process improvement (SPI) and an agent for process learning. We argue that improving awareness information about work processes and about the collaboration intrinsic to it may help software development teams to better accept the idea of defining, standardizing and continuously improving their work. Our approach relies on the use of workflow systems for software process support. We have built an environment—PIEnvironment—by extending a commercial workflow system with awareness information mechanisms and participation channels. Through case studies, we have evaluated its use for the enactment of software process activities. Copyright © 2007 John Wiley & Sons, Ltd.
Uptake of artificial model remnant lipoprotein emulsions by the perfused rat liver
Authors: Redgrave Trevor G. , Maranhao Raul C. , Tercyak Anna M. , Lincoln Elizabeth C. , Brunengraber Henri
Published: January 2007

In comparison with their precursor lipoproteins, the remnants of the triacylglycerol‐rich lipoproteins are reduced in contents of triacylglycerols and apolipoproteins AI and AIV, whereas the contents of cholesterol (free and esterified) and apolipoprotein E are increased. In this study, lipid emulsion models of remnant lipoproteins were used to explore which of these factors are necessary for physiological rates of remnant uptake by the perfused rat liver. Uptake rates of lipid emulsion models of remnant lipoproteins in the presence of apolipoprotein E were similar to in vivo uptake rates.
Chiral discrimination in the exchange of α‐tocopherol stereoisomers between plasma and red blood cells
Authors: Cheng S. C. , Burton G. W. , Ingold K. U. , Foster D. O.
Published: January 2007

The transport of 2R,4′R, 8′R‐α‐tocopherol and 2S,4′R,8′R‐α‐tocopherol from plasma into rat red blood cell membranes occurs with essentially no chiral discrimination. The previously demonstrated (10) preference of red blood cell membranes favoring 2R,4′R,8′R‐α‐tocopherol over the 2S,4′R, 8′R stereoisomer is shown to be due to better retention of the former compound, i.e., to preferential retention of natural vitamin E.
Unsaponifiable matter of green and blue‐green algal lipids as a factor of biochemical differentiation of their biomasses: I. Total unsaponifiable and hydrocarbon fraction
Authors: Paoletti C. , Pushparaj B. , Florenzano G. , Capella P. , Lercker G.
Published: January 2007

As part of a program to study the chemical composition of algal biomasses, the composition of the unsaponifiable matter of the lipids of ten algal species (fiveMyxophyceae and fiveChlorophyceae) was investigated. The total unsaponifiable content, its general composition, and the components of the hydrocarbon fraction are discussed in the present paper. The unsaponifiable content of green algae is constantly higher than that of the blue‐green ones, with the exception ofChlorella. In both algal classes, the major components are hydrocarbons and sterols. Blue‐green algae are richer in hydrocarbons, whereas the green ones contain higher amounts of sterols. In most of the species examined, at least 48 components are present in the hydrocarbon fraction. Each algal species shows a characteristic gas liquid chromatography pattern, but n‐C17 is always one of the most abundant components. Generally, the prokaryotic blue‐green algae show a simpler hydrocarbon composition than the eucaryotic green algae, which contain higher amounts of high mol wt components. Unsaturated hydrocarbons are generally present in very limited quantities, with the exception ofSpirulina sp. andChlorella, sp., which contain a C17 alkene. Green algae also contain appreciable amounts of a C27 monoene and of squalene.
Changes in phospholipids and acyl group composition of rat mammary gland during pregnant, lactating, and post‐weaning periods
Authors: Sun Grace Y. , Leung Benjamin S.
Published: January 2007

The distribution of phospholipids as well as their fatty acid compositions of rat mammary tissues were examined during pregnant, lactating, and post‐weaning periods. There was no apparent change in phospholipids and their acyl groups during the early and late pregnant periods. However, tissue phospholipid composition was different during pregnant, early, and late lactating periods. After parturition, there was a marked increase in the proportion of diacyl‐glycerophosphorylcholine in the phospholipids of mammary tissue, but this proportion decreased gradually during lactation. The decrease in diacyl‐glycerophosphorylcholine during lactation was marked by a corresponding increase in diacyl‐glycerophosphorylethanolamine. Although the shorter chain fatty acids of triglycerides were increased during lactation, only a small proportion of these fatty acids was found in the phosphoglycerides. Marked changes in acyl group composition of individual phospholipids are found during these different physiological stages. In general, there was a rapid decrease in 20∶4 and an increase in 18∶2 in the major phosphoglycerides during parturition. The proportion of 20∶4 in the phosphoglycerides remained low throughout the entire lactating period, while that of 18∶2 continued to increase 2–3 fold. Most of the changes in acyl group of the phosphoglycerides during lactation returned to normal ca. 10 days after weaning. A possible relationship of the variation of phospholipid and acyl group compositions in mammary tissue to changes in hormonal pattern during different physiological stages is discussed.
Simple high vacuum distillation equipment for deodorizing fish oil for human consumption
Authors: Dinamarca E. , Garrido F. , Valenzuela A.
Published: January 2007

A simple piece of glass equipment for deodorizing fish oil (sardine oil) by high vacuum distillation was designed and constructed. The equipment has a throughput of 450–500 ml/hr working at 140°C and at a constant pressure of 2×10−2 mm Hg. It reduces the peroxide value and the cholesterol content of the oil and improves the flavor without affecting the EPA and DHA content.
The processing of exogenous cholesterol in the alveolar compartment of the rat lung
Authors: Hayball Peter J. , Nicholas Terence E.
Published: January 2007

We have examined the esterification of [3H]cholesterol following the intratracheal instillation of a tracer amount into the isolated rat lung perfused with Krebs bicarbonate containing 4.5% albumin. At 5, 30 and 60 min after instillation, lungs were lavaged at 2°C with 3×10 ml of 0.15 M NaCl, each volume instilled and withdrawn three times. Each lung was lavaged at only one time point. The saline recovered was centrifuged at 150 g (5 min) to sediment the macrophage‐rich fraction, leaving the surfactant in the supernatant. The amounts and specific activity of cholesterol and cholesteryl ester were measured following isolation by high performance liquid chromatography of the free cholesterol and the hydrolyzed ester‐derived cholesterol. There was a rapid fall in [3H]cholesterol in the surfactant fraction, accompanied by a reciprocal increase in [3H]cholesteryl ester. Likewise, there was a rapid increase in [3H]cholesteryl ester in the macrophage‐rich fraction, while the level of free [3H]cholesterol in that fraction remained very low. These data are consistent with exogenous cholesterol being rapidly esterified in the alveolus, and the ester then being cleared by the macrophages. We were unable to locate the actual site of esterification. Lipids
Specific susceptibility of docosahexaenoic acid and eicosapentaenoic acid to peroxidation in aqueous solution
Authors: Bruna E. , Petit E. , Beljean‐Leymarie M. , Huynh S. , Nouvelot A.
Published: January 2007

The peroxidation of different polyunsaturated fatty acids (PUFA) after photoirradiation in aqueous solution was evaluated by measuring fatty acid loss and malonaldehyde production in medium. The oxidation rates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two highly unsaturated fatty acids of the n−3 series, were surprisingly lower (14 and 22%, respectively) than the oxidation rates of linoleic, α‐linolenic, γ‐linolenic, dihomo γ‐linolenic, and arachidonic acids (62–90%). The quantities of malonaldehyde (MA) produced were assayed simultaneously by gas chromatography (GC) and high performance liquid chromatography (HPLC). MA production was found to be related to both the degree of unsaturation and the metabolic series of the fatty acid. The maximum value was observed with arachidonic acid (MA production from 2 mM arachidonic acid in aqueous solution was estimated at 44.9±6.0 μM by GC and 46.8 ±4.0 μM by HPLC). Eicosapentaenoic acid and docosahexaenoic acid produced lower MA quantities compared to arachidonic acid (MA production from 2 mM EPA and 2 mM DHA was estimated at 17.9±1.5 μM and 37.9±0.7 μM, respectively, by GC, and 26.3±4.9 μM and 37.3±4.2 μM, respectively, by HPLC). The MA yield, defined as the amount of MA (nmols) produced per 100 nanomoles of oxidized fatty acid, was used to express the susceptibility of individual PUFA to peroxidation. The MA yield correlated well with the degree of unsaturation, but was independent of carbon chain length and metabolic series. The study suggests that adequate assessment of lipid peroxidation cannot be achieved by measuring MA formation alone, but it also requires knowledge of the fatty acid composition of the system studied.
Rapid headspace gas chromatography of hexanal as a measure of lipid peroxidation in biological samples
Authors: Frankel E. N. , Hu M. ‐L. , Tappel A. L.
Published: January 2007

A rapid, sensitive and convenient capillary gas chromatographic‐headspace method was developed to determine hexanal as an important volatile decomposition product of hydroperoxides formed from n−6 polyunsaturated fatty acids in rat liver samples. Total volatiles were also determined as a measure of overall lipid peroxidation. Samples of headspace taken from sealed serum bottles incubated at 37°C were injected into a gas chromatograph. It was possible to make 15 determinations per hour. This method is convenient because no special sample manipulations are necessary. The addition of 0.5 mM ascorbic acid prior to gas chromatographic, analysis significantly increased hexanal production. The applicability of the method was demonstrated in studies of the effect of iron in the presence or absence of hydroperoxides of methyl linoleate and methyl linolenate andtert‐butyl hydroperoxide on rat liver homogenates, slices and microsomes. A rapid silica cartridge chromatographic procedure was used to purify hydroperoxides from autoxidized methyl linoleate and methyl linolenate, and hydroperoxy epidioxides (cyclic peroxides) from autoxidized methyl linolenate in 20–40 mg quantities. The hydroperoxides and hydroperoxy epidioxides of methyl linolenate were, effective inducers n−6 polyunsaturated fatty acid peroxidation in liver homogenates. Hexanal and thiobarbituric acid‐reacting substances were signficantly correlated in liver homogenates and microsomes but not in slices. This specific method for hexanal, a known product of peroxidation of n−6 polyunsaturated fatty acids, can be used as a good measure of lipid peroxidation.
Inhibition and induction of bile acid synthesis by ketoconazole effects on bile formation in the rat
Authors: Kuipers Folkert , Havinga Rick , Huijsmans Christine M. G. , Vonk Roel J. , Princen Hans M. G.
Published: January 2007

The effects of ketoconazole, an antimycotic agent, and metyrapone, an inhibitor of mixed function oxidases, on bile acid synthesis were compared in the rat bothin vitro andin vivo. In rat liver microsomes, ketoconazole was much more potent than metyrapone in inhibiting the activity of cholesterol 7α‐hydroxylase, the rate‐limiting enzyme in the synthesis of bile acids. The I50 values were 0.42 μM and 0.91 mM for ketoconazole and metyrapone, respectively. Intraduodenal administration of ketoconazole caused a rapid, dose‐dependent reduction of bile acid synthesis in eight‐day bile diverted rats. A single dose of 50 mg/kg reduced bile acid synthesis to 5% of control value; the same dose of metyrapone caused a reduction to only 85%. Inhibition of bile acid synthesis by ketoconazole was followed by a marked overshoot. At 28 hr after injection of 50 mg/kg of the drug, formation of bile acids was stimulated maximally by 45% compared to control value and remained elevated for more than 20 hr thereafter. Synthesis of all primary bile acids was affected to the same extent. Cholesterol 7α‐hydroxylase activity in livers of ketoconazole treated (30 mg/kg) rats with an intact enterohepatic circulation was increased by 70% at 16 hr after i.p. injection of the drug. During the very large decrease of biliary bile acid output with ketoconazole, bile flow rate was relatively increased, due to stimulation of the bile acid‐independent fraction of bile flow. The latter effect can probably be explained as caused by biliary secretion of osmotically active metabolites of ketoconazole.
Ozone‐induced alterations of lamellar body lipid and protein during alveolar injury and repair
Authors: Shelley Sue A. , Paciga June E. , Paterson James F. , Balis John U.
Published: January 2007

Alveolar Type II cells in the rat respond to severe, acute ozone injury (3 ppm ozone for eight hours) by increasing their intracellular pool of surfactant; however, the newly stored surfactant is abnormal in composition. Lamellar bodies isolated between 24 and 96 hours after ozone exposure contained significantly more cholesterol in relation to phosphatidylcholine than did controls. By contrast, the cholesterol content of surfactant isolated from alveolar lavage remained unchanged throughout an 8‐day post‐ozone period. The total protein content of lamellar bodies in relation to phosphatidylcholine was significantly decreased at 24 and 48 hours post‐ozone. Analysis of lamellar body proteins by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the amount of a 14 kDa proteolipid was greatly reduced at the end of the eight‐hour ozone exposure and remained low for at least 48 hours. This proteolipid appeared to be a specific lamellar body component since it was not detected in extracellular surfactant. The findings indicate that oxidative alveolar stress initiates characteristic alterations in both lipid and protein constituents of stored surfactant, without perturbation in the composition of extracellular surfactant.
Involvement of phosphatidylinositol‐3‐kinase and ERK pathways in the production of TGF‐β1 by macrophages treated with liposomes composed of phosphatidylserine
Authors: Otsuka Masaki , Negishi Yoichi , Aramaki Yukihiko
Published: January 2007

We explored the involvement of phosphatidylinositol 3‐kinase (PI3K) and ERK pathways in the production of TGF‐β1 by macrophages treated with liposomes composed of phosphatidylserine (PS‐liposomes). PS‐liposomes activated Akt, downstream of the PI3K signal cascade, and ERK which led to the expression of TGF‐β1. PI3K inhibitors, LY294002 and wortmannin, inhibited the activation of Akt and ERK following the treatment with PS‐liposomes. These inhibitors also suppressed the production of TGF‐β1. Furthermore, PS‐liposomes activated macrophages to induce TGF‐β1 expression through PS‐specific receptors. These findings suggested that a PI3K‐ERK signaling pathway via the PS‐receptor is intimately involved in the production of TGF‐β1 which regulates macrophage functions.
Rheology of surface granular flows
Authors: ORPE ASHISH V. , KHAKHAR D. V.
Published: January 2007

Surface granular flow, comprising granular material flowing on the surface of a heap of the same material, occurs in several industrial and natural systems. The rheology of such a flow was investigated by means of measurements of velocity and number-density profiles in a quasi-two-dimensional rotating cylinder, half-filled with a model granular material – monosize spherical stainless-steel particles. The measurements were made at the centre of the cylinder, where the flow is fully developed, using streakline photography and image analysis. The stress profile was computed from the number-density profile using a force balance which takes into account wall friction. Mean-velocity and root-mean-square (r.m.s.)-velocity profiles are reported for different particle sizes and cylinder rotation speeds. The profiles for the mean velocity superimpose when distance is scaled by the particle diameterdand velocity by a characteristic shear rate$\dot{\gamma}_C = [g\sin(\beta_m-\beta_s)/d\cos\beta_s]^{1/2}$and the particle diameter, where βmis the maximum dynamic angle of repose and βsis the static angle of repose. The maximum dynamic angle of repose is found to vary with the local flow rate. The scaling is also found to work for the r.m.s. velocity profiles. The mean velocity is found to decay exponentially with depth in the bed, with decay length λ = 1.1d. The r.m.s. velocity shows similar behaviour but with λ = 1.7d. The r.m.s. velocity profile shows two regimes: near the free surface the r.m.s. velocity is nearly constant and below a transition point it decays linearly with depth. The shear rate, obtained by numerical differentiation of the velocity profile, is not constant anywhere in the layer and has a maximum which occurs at the same depth as the transition in the r.m.s. velocity profile. Above the transition point the velocity distributions are Gaussian and below the transition point the velocity distributions gradually approach a Poisson distribution. The shear stress increases roughly linearly with depth. The variation in the apparent viscosity η with r.m.s. velocityushows a relatively sharp transition at the shear-rate maximum, and in the region below this point the apparent viscosity η ∼u−1.5. The measurements indicate that the flow comprises two layers: an upper low-viscosity layer with a nearly constant r.m.s. velocity and a lower layer of increasing viscosity with a decreasing r.m.s. velocity. The thickness of the upper layer depends on the local flow rate and is independent of particle diameter while the reverse is found to hold for the lower-layer thickness. The experimental data is compared with the predictions of three models for granular flow.
Direct simulations of a rough-wall channel flow
Authors: IKEDA TOMOAKI , DURBIN PAUL A.
Published: January 2007

In this study, we performed simulations of turbulent flow over rectangular ribs transversely mounted on one side of a plane in a channel, with the other side being smooth. The separation between ribs is large enough to avoid forming stable vortices in the spacing, which exhibitsk-type, or sand-grain roughness. The Reynolds numberReτof our representative direct numerical simulation case is 460 based on the smooth-wall friction velocity and the channel half-width. The roughness heighthis estimated as 110 wall units based on the rough-wall friction velocity. The velocity profile and kinetic energy budget verify the presence of an equilibrium, logarithmic layer aty≳2h. In the roughness sublayer, however, a significant turbulent energy flux was observed. A high-energy region is formed by the irregular motions just above the roughness. Visualizations of vortical streaks, disrupted in all three directions in the roughness sublayer, indicate that the three-dimensional flow structure of sand-grain roughness is replicated by the two-dimensional roughness, and that this vortical structure is responsible for the high energy production. The difference in turbulence structure between smooth- and rough-wall layers can also be seen in other flow properties, such as anisotropy and turbulence length scales.
A statistical theory of turbulent relative dispersion
Authors: FRANZESE P. , CASSIANI M.
Published: January 2007

The laws governing the spread of a cluster of particles in homogeneous isotropic turbulence are derived using a theoretical approach based on inertial subrange scaling and statistical diffusion theory. The equations for the mean square dispersion of a puff admit an analytical solution in the inertial subrange and at large scales. The solution is consistent with Taylor's theory of absolute dispersion. An analytical derivation of the Richardson–Obukhov constant of relative dispersion is presented. A time scale for relative dispersion is identified, as well as relations between Lagrangian and Eulerian structure functions. The results are extended to turbulence at finite Reynolds number. A closure assumption for the relative kinetic energy, based on Taylor's theory, is presented. Comparisons with direct numerical simulations and laboratory experiments are reported.
Endoscopic control of the sphenopalatine artery for epistaxis: long-term results
Authors: Abdelkader M , Leong S C , White P S
Published: January 2007

The aim of this study was to prospectively evaluate post-operative cessation of bleeding and late recurrence of epistaxis in a cohort of patients treated by endoscopic ligation of the sphenopalatine artery. Participants comprised patients undergoing sphenopalatine artery ligation for posterior epistaxis at three east Scotland hospitals. Main outcome measures were recurrence of epistaxis in the immediate post-operative period and at long-term follow up (minimum nine months). Forty-three patients (30 men and 13 women) underwent 45 procedures; two patients underwent bilateral ligation. Two patients suffered recurrence as in-patients. Two patients experienced subsequent epistaxis requiring medical treatment. Two further patients suffered minor late epistaxis not requiring treatment. Success in preventing significant recurrence was 93 per cent. All recurrences requiring intervention occurred within one month of surgery. None of the patients in this series reported nasal complications. We found sphenopalatine artery ligation to be an effective means of achieving long-term control of posterior epistaxis.