bluuebunny/crossref_metadata_2025 huggingface dataset:
EX POST VERSUS EX ANTE MEASURES OF THE USER COST OF CAPITAL
Authors: Oulton Nicholas
Published: May 2007

Should we use ex post or ex ante measures of user costs to calculate the contribution of capital in a growth accounting exercise? The answer, based on a simple model of temporary equilibrium, is that ex post is better in theory. In practice researchers usually calculate ex post user costs by assuming that the rate of return is equalized across assets. But this is only true if expectations are correct. In general, the ex post rate of return differs between assets, even though ex ante it is the same. I propose a hybrid method. The index of capital services is estimated using ex ante weights; the contribution of capital is the growth of this index multiplied by the ex post income share of capital. I show that this method is theoretically correct if the production function is CES. I compare the ex post, ex ante and hybrid methods using data for 31 U.K. industries from 1970 to 2000.
MEASURING THE LIFETIME REDISTRIBUTION ACHIEVED BY DUTCH TAXATION, CASH TRANSFER AND NON‐CASH BENEFITS PROGRAMS
Authors: Ter Rele Harry
Published: May 2007

This paper assesses how the Dutch system of taxation, cash transfers and non‐cash benefits redistributes between the rich and the poor. The approach in this paper deviates from the usual approach by incorporating the full life cycle in the measurements, rather than only the annual effects. Moreover, the coverage is larger than is usually the case: the paper takes account of both direct and indirect taxes and direct and indirect benefits. In order to obtain the measurements on redistribution, we use the level of educational attainment to classify the population. We therefore measure, in terms of present values, the average net benefit from government policies for an average representative person of each level of education. The results indicate a sizable redistribution from the rich to the poor and a significant reduction of welfare inequality. The net effect on welfare inequality is, however, substantially smaller than when measured on an annual basis.
THE MONETARY METHOD AND THE SIZE OF THE SHADOW ECONOMY: A CRITICAL ASSESSMENT
Authors: Ahumada Hildegart , Alvaredo Facundo , Canavese Alfredo
Published: May 2007

A widely applied approach to measure the size of the shadow economy, known as the “monetary method” or the “currency approach,” is based on econometric estimates of the demand for money. These estimates are used to get the currency held by economic agents in excess of the amount they need to finance registered transactions. This excess of currency multiplied by the income‐velocity of circulation (assumed to be equal in the registered and shadow economies) gives a measure of the hidden GDP. This paper shows that the monetary method only produces coherent estimates if the income‐elasticity of the demand for currency is one and suggests a way to correct the estimated size of the shadow economy when such elasticity is not one. The correction is applied to existent measures for different countries.
MULTILATERAL INDICES: CONFLICTING APPROACHES?
Authors: Quiggin John , Van Veelen Matthijs
Published: May 2007

This short paper focusses on an apparent conflict between two results from different approaches to the problem of finding multilateral index numbers. The impossibility theorem of Van Veelen (2002) is an axiomatic result that rules out the existence of a multilateral index that satisfies four modest requirements. This also implies that no bilateral index can consistently be generalized to a multilateral setting. Adopting a revealed preference approach, Dowrick and Quiggin (1997) however construct a multilateral extention of Fisher's ideal index, which preserves a range of desirable properties. This note shows what it is that drives the divergence between those two results. It also gives implications for practical use of results from either approach.
From jellied seas to open waterways: redefining the northern limit of the knowable world
Authors: Small Margaret
Published: May 2007

In the ancient world, the northern limits of Europe were unknown, and believed to be unknowable. Geographers constructed a mental framework for the continent that restricted human inhabitation to more southerly regions. The constituents of this frame were: a region of monstrous creatures, a zone of uninhabitable wastelands, and ultimately, limitless ocean. By the sixteenth century, classically educated Europeans were sailing into the unknown Arctic regions in search of a north‐east passage, but their descriptions and even goals for exploration were still influenced by the classical preconceptions. The three elements of the classical frame were altered, but persisted in European geographical thought even after fifty years of northern exploration.
Between friends? Two letters of Ippolita Sforza to Lorenzo de’ Medici
Authors: Bryce Judith
Published: May 2007

This article examines aspects of the relationship of Lorenzo de’ Medici and Ippolita Sforza, Duchess of Calabria, through a close reading of two familiar letters by the latter dating from 1480 and 1486. The reading takes into account the respective political contexts of these letters – the end of the War of the Pazzi Conspiracy and of the Barons’ Revolt respectively – but seeks above all to use them to explore the nature of a ‘friendship’ complicated by the political and dynastic agendas of the two individuals as well as by issues of status and, particularly, of gender.
Demonology on the margins: Robert Du Triez's Les Ruses, finesses et impostures des espritz malins (1563)
Authors: Chesters Timothy
Published: May 2007

Published in Cambrai in 1563, Robert du Triez's Les Ruses, finesses et impostures des espritz malins has good claim to the be the first prose demonology published in French. And yet Les Ruses has received surprisingly little scholarly attention. This article offers both an introduction to Du Triez and his text, and some reflections on a blind spot in the historiography of early modern French demonology. Les Ruses might be described as marginal in at least four respects. i) chronology: Du Triez's text appeared some fifteen years before the heyday of vernacular French demonology. ii) geopolitics: an archer in the army of Philip II, Du Triez's allegiances were not to France, but to the Empire, and to the Counter‐Reformation initiatives at the newly founded college at Douai iii) thematics: Les Ruses contains no discussion of witchcraft and the pact. iv) style and tone: the author accords an unusual degree of attention to the question of narrative pleasure. What emerges most powerfully from Les Ruses is that early modern demons were not always so much a matter of what it is we should believe, as the kinds of stories they allow us to tell.
Dietary iron overload in the African and hepatocellular carcinoma
Authors: Kew Michael C. , Asare George A.
Published: May 2007

Dietary iron overload occurs commonly in parts of sub‐Saharan Africa. It results from the consumption of large volumes of traditional beer that is home‐brewed in iron pots or drums and consequently has a high iron content. The liver becomes iron overloaded and may develop portal fibrosis or, less often, cirrhosis. A genetic predisposition to the condition has been suggested, but no putative gene has yet been identified. Although originally believed not to cause hepatocellular carcinoma, recent case–control studies have shown African Blacks with dietary iron overload to be at increased risk for the tumour and a causal association has been confirmed in an animal model. The mechanisms of iron‐induced malignant transformation are yet to be fully characterised, but the close association between cirrhosis and hepatocellular carcinoma in patients with hereditary haemochromatosis and the lesser association in those with dietary iron overload, suggests that chronic necroinflammatory hepatic disease contributes to the malignant transformation. Increased hepatic iron may, however, also be directly carcinogenic. Probable mechanisms include the generation of reactive oxygen intermediates and the resultant chronic oxidative stress that damages hepatocytes and proteins, causes lipid peroxidation, and induces strand breaks, DNA unwinding, and mutations in tumour‐suppressor genes and critical DNA repair genes.
Managing Multiple Cardiovascular Risk Factors: State of the Science
Authors: Levine Jon H.
Published: May 2007

Cardiovascular risk comprises genetic, lifestyle, and metabolic factors. Risk factors frequently occur simultaneously, compounding the risk for a cardiovascular event. The most commonly occurring metabolic clustering includes elevated blood pressure, dyslipidemia (high triglyceride levels and low levels of high‐density lipoprotein cholesterol), and impaired glucose tolerance or type 2 diabetes mellitus. Together with visceral obesity, this clustering of risk factors is known as the metabolic syndrome. Although the definition of the metabolic syndrome and its relevance in clinical practice are the subject of discussion, there is emerging consensus about the importance of treating all risk factors early and aggressively. Recent evidence suggests that new‐onset diabetes mellitus and microalbuminuria are independent risk factors that should be considered when assessing composite cardiovascular risk. Treatment should be tailored to a patient's risk profile, with consideration of the varying effects that agents of different therapeutic classes have on cardiovascular and metabolic parameters.
Organ Systems Dependent on Nitric Oxide and the Potential for Nitric Oxide‐Targeted Therapies in Related Diseases
Authors: Hollenberg Norman K.
Published: May 2007

Nitric oxide (NO) is a universal messenger molecule that plays diverse and essential physiologic roles in multiple organ systems, including the vasculature, bone, muscle, heart, kidney, liver, and central nervous system. NO is produced by 3 known isoforms—endothelial, neuronal, and inducible NO synthase—each of which perform distinct functions. Impairment of NO bioactivity may be an important factor in the pathogenesis of a wide range of conditions, including preeclampsia, osteoporosis, nephropathy, liver disease, and neurodegenerative diseases. Although increased levels of NO synthase or NO bioactivity have been associated with some of these disease states, research increasingly suggests that preservation or promotion of normal NO bioactivity may be beneficial in reducing the risks and perhaps reversing the underlying pathophysiology. Based on this rationale, studies investigating the use of NO‐donating or NO‐promoting agents in some of these diseases have produced positive results, at least to some degree, in either animal or human studies. Further investigation of NO‐targeted therapies in these diverse diseases is clearly mandated.
Planning for pandemic influenza: effect of a pandemic on the supply and demand for blood products in the United States
Authors: Zimrin Ann B. , Hess John R.
Published: May 2007

BACKGROUND: Influenza causes episodic pandemics when viral antigens shift in ways that elude herd immunity. Avian influenza A H5N1, currently epizootic in bird populations in Asia and Europe, appears to have pandemic potential.

STUDY DESIGN AND METHODS: The virology of influenza, the history of the 1918 pandemic, and the structure of the health care and the blood transfusion systems are briefly reviewed. Morbidity and mortality experience from the 1918 pandemic are projected onto the current health care structure to predict points of failure that are likely in a modern pandemic.

RESULTS: Blood donor centers are likely to experience loss of donors, workers, and reliable transport of specimens to national testing laboratories and degradation of response times from national testing labs. Transfusion services are likely to experience critical losses of workers and of reagent red cells (RBCs) that will make their automated procedures unworkable. Loss of medical directors, supervisors, and lead technicians may make alternative procedures unworkable as well.

CONCLUSIONS: Lower blood collection capacity and transfusion service support capability will reduce the availability of RBCs and especially of platelets. Plans for rationing medical care need to take the vulnerability of the blood transfusion system into account.
Randomized clinical trials in implant therapy: relationships among methodological, statistical, clinical, paratextual features and number of citations
Authors: Nieri Michele , Clauser Carlo , Franceschi Debora , Pagliaro Umberto , Saletta Daniele , Pini‐Prato Giovanpaolo
Published: May 2007

Objectives: The aim of the present study was to investigate the relationships among reported methodological, statistical, clinical and paratextual variables of randomized clinical trials (RCTs) in implant therapy, and their influence on subsequent research.

Materials and Methods: The material consisted of the RCTs in implant therapy published through the end of the year 2000. Methodological, statistical, clinical and paratextual features of the articles were assessed and recorded. The perceived clinical relevance was subjectively evaluated by an experienced clinician on anonymous abstracts. The impact on research was measured by the number of citations found in the Science Citation Index. A new statistical technique (Structural learning of Bayesian Networks) was used to assess the relationships among the considered variables.

Results: Descriptive statistics revealed that the reported methodology and statistics of RCTs in implant therapy were defective. Follow‐up of the studies was generally short. The perceived clinical relevance appeared to be associated with the objectives of the studies and with the number of published images in the original articles. The impact on research was related to the nationality of the involved institutions and to the number of published images.

Conclusions: RCTs in implant therapy (until 2000) show important methodological and statistical flaws and may not be appropriate for guiding clinicians in their practice. The methodological and statistical quality of the studies did not appear to affect their impact on practice and research. Bayesian Networks suggest new and unexpected relationships among the methodological, statistical, clinical and paratextual features of RCTs.
Early functional loading of sand‐blasted and acid‐etched (SLA) Straumann implants following immediate placement in maxillary extraction sockets. Clinical and radiographic result
Authors: Nordin Thomas , Graf Johan , Frykholm Anders , Helldén Leif
Published: May 2007

Objectives: To present the clinical and radiographic outcome of early loading of implants inserted into fresh extraction sockets and to present a treatment protocol for early loading of the implants by ‘passively fitting’ abutment‐free permanent fixed complete dentures (implant FCDs).

Material and methods: The study included 19 dentate patients treatment planned for extraction of all remaining maxillary teeth. In all, 116 Straumann‐implants with sandblasted, large grit and acid etched (SLA) surface were placed: 77 (66%) inserted in fresh extraction sockets and 39 (34%) in healed bone. At least six implants were placed in each maxilla. One hundred and ten implants were loaded by permanent FCDs within 10 days after placements and six after 14 days. The patients were reexamined clinically and radiographically after 2–3 years of clinical function. All FCDs were removed for control of implant stability and evaluation of the peri‐implant status.

Results: Owing to framework fracture, two implants were lost, corresponding to a failure rate of 2%. The radiographic measurements after 2–3 years did not reveal any difference in bone height mesial and distal of the implants placed in extraction sockets vs. in healed bone. This was interpreted as a bone gain around the implants placed in extraction sockets and a slight bone loss around the implants placed in healed bone.

Conclusion: Early functional loading of SLA‐surfaced implants following immediate placement in maxillary extraction sockets by rigid and passively fitting permanent implant FCDs is a reliable treatment alternative.
Plakoglobin‐dependent disruption of the desmosomal plaque in pemphigus vulgaris
Authors: De Bruin Alain , Caldelari Reto , Williamson Lina , Suter Maja M. , Hunziker Thomas , Wyder Marianne , Müller Eliane J.
Published: May 2007

Abstract:  We recently reported that the pathogenesis of pemphigus vulgaris (PV), an autoimmune blistering skin disorder, is driven by the accumulation of c‐Myc secondary to abrogation of plakoglobin (PG)‐mediated transcriptional c‐Myc suppression. PG knock‐out mouse keratinocytes express high levels of c‐Myc and resemble PVIgG‐treated wild‐type keratinocytes in most respects. However, they fail to accumulate nuclear c‐Myc and loose intercellular adhesion in response to PVIgG‐treatment like wild‐type keratinocytes. This suggested that PG is also required for propagation of the PVIgG‐induced events between augmented c‐Myc expression and acantholysis. Here, we addressed this possibility by comparing PVIgG‐induced changes in the desmosomal organization between wild‐type and PG knock‐out keratinocytes. We found that either bivalent PVIgG or monovalent PV‐Fab (known to trigger blister formation in vivo) disrupt the linear organization of all major desmosomal components along cell borders in wild‐type keratinocytes, simultaneously with a reduction in intercellular adhesive strength. In contrast, PV‐Fab failed to affect PG knock‐out keratinocytes while PVIgG cross‐linked their desmosomal cadherins without significantly affecting desmoplakin. These results identify PG as a principle effector of the PVIgG‐induced signals downstream of c‐Myc that disrupt the desmosomal plaque at the plasma membrane.
Lessons learned from DNA repair defective syndromes
Authors: Thoms Kai‐Martin , Kuschal Christiane , Emmert Steffen
Published: May 2007

Abstract:  Genomic instability is the driving force behind cancer development. Human syndromes with DNA repair deficiencies comprise unique opportunities to study the clinical consequences of faulty genome maintenance leading to premature aging and premature cancer development. These syndromes include chromosomal breakage syndromes with defects in DNA damage signal transduction and double‐strand break repair, mismatch repair defective syndromes as well as nucleotide excision repair defective syndromes. The same genes that are severely affected in these model diseases may harbour more subtle variations in the ‘healthy’ normal population leading to genomic instability, cancer development, and accelerated aging at later stages of life. Thus, studying those syndromes and the molecular mechanisms behind can significantly contribute to our understanding of (skin) cancerogenesis as well as to the development of novel individualized preventive and therapeutic anticancer strategies. The establishment of centers of excellence for studying rare genetic model diseases may be helpful in this direction.
Differential p53‐mediated responses to solar‐simulated radiation in human papillomavirus type 16‐infected keratinocytes
Authors: Mouret Stéphane , Favier Alain , Beani Jean‐Claude , Leccia Marie‐Thérèse
Published: May 2007

Abstract:  In immunocompromised patients, cooperative effects of human papillomavirus (HPV) and ultraviolet (UV) radiation have been postulated in the development of non‐melanoma skin cancers. The tumor suppressor p53 is a key component of the cellular response to genotoxic agents, such as UV radiation. We have previously demonstrated that in HPV16‐infected cells, a higher E6* level was associated with a higher resistance to UV and oxidative stress. Using the two same SKv cell lines, the aim of the present study was to investigate p53 and p21 expression and cell death in HPV‐infected keratinocytes in response to UV irradiation and to determine the role of HPV oncoprotein levels on the p53‐mediated cellular response. We demonstrated that the weakly E6*‐expressing level SKv‐e cell line presented both higher cytotoxicity and apoptosis to UV. This high sensitivity was associated with both p53 and p21 nuclear accumulation, while a high E6* level and resistance were associated with no p53 accumulation and a p21 nuclear down‐regulation after UV. Moreover, in SKv‐e cell line, p21 promoter activation was p53 dependent. Our results suggest that an alteration and/or a modulation of the p53–p21 pathway in response to UV could be determinant for HPV‐infected keratinocyte survival and HPV‐associated carcinogenic process.
Human tissue kallikrein expression in the stratum corneum and serum of atopic dermatitis patients
Authors: Komatsu Nahoko , Saijoh Kiyofumi , Kuk Cynthia , Liu Amber C. , Khan Saba , Shirasaki Fumiaki , Takehara Kazuhiko , Diamandis Eleftherios P.
Published: May 2007

Abstract:  Human tissue kallikreins are a family of 15 trypsin‐ or chymotrypsin‐like secreted serine proteases (KLK1–KLK15). Many KLKs have been identified in normal stratum corneum (SC) and sweat, and are candidate desquamation‐related proteases.

We report quantification by enzyme‐linked immunosorbent assay (ELISA) of KLK5, KLK6, KLK7, KLK8, KLK10, KLK11, KLK13 and KLK14 in the SC and serum of atopic dermatitis (AD) patients by ELISA, and examine their variation with clinical phenotype, correlation with blood levels of eosinophils, lactate dehydrogenase (LDH) and immunoglobulin E. The overall SC serine protease activities were also measured.

In the SC of AD, all KLKs, except KLK11, were significantly elevated. The elevation of chymotrypsin‐like KLK7 was predominant, compared with trypsin‐like KLKs. The SC overall plasmin‐ and furin‐like activities were significantly elevated, while trypsin‐ and chymotrypsin‐like activities did not differ significantly. In the serum of AD patients, KLK8 was significantly elevated and KLK5 and KLK11 were significantly decreased. However, their serum levels were not modified by corticosteroid topical agents. The alterations of KLK levels in the SC of AD were more pronounced than those in the serum. KLK7 in the serum was significantly correlated with eosinophil counts in the blood of AD patients, while KLK5, KLK8 and KLK11 were significantly correlated with LDH in the serum.

In conclusion, we report abnormal kallikrein levels in the SC and the serum of AD patients. KLKs might be involved in skin manifestation and/or focal/systemic inflammatory reactions in AD. Our data may contribute to a better understanding of the pathogenesis of AD.
Microarray analysis of nicotine‐induced changes in gene expression in a macrophage‐like human cell line
Authors: Koshi R. , Sugano N. , Orii H. , Fukuda T. , Ito K.
Published: May 2007

Background and Objective:  Cigarette smoking has been suggested as a risk factor for periodontitis. Thousands of components are present in cigarette smoke, including nicotine, which may play an important role in the observed effects of smoking on cell metabolism. However, the mechanisms underlying these effects are unclear. Using DNA microarrays, we monitored differentially expressed genes, responsive to nicotine, in a macrophage‐like human cell line.

Material and Methods:  Human U937 cells were treated for 1 h, with or without 1.0 µg/ml of nicotine. For differentiation, cultures were incubated with 10 nm phorbol myristate acetate for 48 h. Analysis of gene expression was performed using a DNA microarray of 8500 genes.

Results:  The expression of 4914 genes was detected. Screening was carried out on those genes whose expression in three separate experiments showed an average change of twofold or greater, and 118 up‐regulated genes and 97 down‐regulated genes were identified. Among these were genes related to inflammation and other immune responses, such as phospholipase A2 and interferon. Consistent with the array findings, we found similar changes in mRNA expression after analysis using the real‐time polymerase chain reaction.

Conclusion:  The results suggest that nicotine causes excess inflammation and disturbs host defense mechanisms against pathogens.
Genetic factors associated with skin cancer in renal transplant patients
Authors: Laing Mary Elizabeth , Kay Elaine , Conlon Peter , Murphy Gillian M.
Published: May 2007

Background: Non‐melanoma skin cancer represents a significant cause of morbidity and mortality among renal transplant recipients. Established risk factors that increase susceptibility to skin cancer after transplantation include skin type, sun exposure and level of immunosuppression.

Methods: A comprehensive literature review was carried out to discuss relevant genetic polymorphism for the development of skin cancer in organ transplant recipients. These include genetic polymorphisms in glutathione S‐transferase, interleukin‐10, retinoblastoma and p53 genes. We also discuss genetic polymorphisms in the folate pathway, melanocortin 1 receptor and vitamin D receptor recently discovered in our group.

Results: No single factor is causative in cutaneous carcinogenesis in transplant recipients. Interactions of some of the above mechanisms with known environmental factors lead to increased risk.

Conclusion: Polymorphisms in methylenetetrahydrofolate reductase are potentially correctable with folic acid supplementation; however, further evaluation is required in adequately powered prospective clinical trials. Avoidance of known oncogenic environmental factors and genetic risk evaluation may improve outcomes in transplant patients.
Topical application of plant extracts containing xanthine derivatives can prevent UV‐induced wrinkle formation in hairless mice
Authors: Mitani Hiroaki , Ryu Akemi , Suzuki Tadashi , Yamashita Mika , Arakane Kumi , Koide Chiharu
Published: May 2007

Background: Plants are the source of important products with nutritional and therapeutic value. Topical or oral administration of some plant extracts has been shown to reduce photodamage. Cacao bean and cola nut are popular edible plants that contain polyphenols and xanthine derivatives. These plant extracts possess protective effects against UV‐induced erythema when taken orally, and an H2O2‐scavenging effect.

Methods: Plant extracts containing xanthine derivatives and three xanthine derivatives were topically applied to the dorsal skin of hairless mice, and the mice were exposed to a resemblance of solar ultraviolet irradiation at a dose of 13.0 J/cm2 (UVA) for 15 weeks, five times a week on weekdays. After the final irradiation, histological, and analytical studies were performed.

Results: Topical application of plant extracts (cacao beans, cola nuts) and caffeine, theobromine, and theophylline markedly prevented photodamage including wrinkle formation and histological alterations. A significant increase in total hydroxyproline content caused by UV irradiation was observed. In contrast, topical application of plant extracts and xanthine derivatives reduced total hydroxyproline and pepsin‐resistant hydroxyproline content in comparison with that of the control (vehicle, UV‐irradiation group). Moreover, naphthol AS‐D chloroacetate esterase staining and diaminobenzidine staining suggested that leukocytes including neutrophils increased in the UV‐exposed skin. In contrast, weak staining was observed in skin treated with xanthine derivatives.

Conclusion: Topical application of plant extracts and xanthine derivatives suppressed wrinkle formation, dermal connective alteration, and collagen accumulation. It is suggested that xanthine derivatives prevented neutrophil infiltration caused by UV‐irradiation.
Analysis of procedures used in tooth avulsion by 100 dental surgeons
Authors: Manfrin Thais Mara , Boaventura Renata Santos , Poi Wilson Roberto , Panzarini Sônia Regina , Sonoda Celso Koogi , Sundefeld Maria Lúcia Marçal Massa
Published: May 2007

Abstract –  Accurate diagnosis and adequate treatment plan may constitute very complex tasks, particularly in tooth avulsion, because several variables are involved. In addition to the technical knowledge and clinical experience directed toward the quality of treatment, patient education may favorably influence the survival of replanted teeth. The aim of this study was to analyze the procedures used in the management of tooth avulsion by 100 dental surgeons (DSs). Thus, by means of a descriptive questionnaire, information was obtained about the profile of the professionals interviewed, procedures used in cases of tooth avulsion, and patient orientation and education. One hundred properly filled questionnaires were obtained. Descriptive statistics was used for the data, and the chi‐squared statistics was employed (epi‐info 3.2 software). According to the results, this type of trauma is part of the routine of 15 DSs, although 71 have reported some experience with avulsed teeth. Great deficiencies were found regarding root surface treatment and occlusal adjustment. Positive findings were related to socket treatment, adjunctive therapy, and patient education and orientation (extra‐alveolar period, storage medium, manipulation of the avulsed tooth, replantation by the own patient). It was possible to conclude that 47.5% of the procedures reported by 100 professionals interviewed are adequate, and patient education is favorable in 87.7% of cases, a fact that can positively interfere with the prognosis of tooth replantation.
α‐d‐Mannopyranosyl‐(1→2)‐α‐d‐glucopyranosyl‐(1→2)‐glycerate in the thermophilic bacterium Petrotoga miotherma − structure, cellular content and function
Authors: Jorge Carla D. , Lamosa Pedro , Santos Helena
Published: May 2007

The intracellular accumulation of low molecular mass organic compounds in response to stressful conditions was investigated in the thermophilic bacterium Petrotoga miotherma, a member of the order Thermotogales. This led to the discovery of a new solute, whose structure was established as α‐d‐mannopyranosyl‐(1→2)‐α‐d‐glucopyranosyl‐(1→2)‐glycerate (MGG) by MMR spectroscopy and MS. Under optimum growth conditions (3% NaCl; 55 °C), MGG was the major solute [up to 0.6 µmol·(mg protein)−1]; α‐glutamate and proline were also present but in minor amounts [below 0.08 µmol·(mg protein)−1]. The level of MGG increased notably with the salinity of the growth medium up to the optimum NaCl concentration. At higher NaCl concentrations, however, the level of MGG decreased, whereas the levels of proline and α‐glutamate increased about five‐fold and 10‐fold, respectively. MGG plays a role during low‐level osmotic adaptation of Petrotoga miotherma, whereas α‐glutamate and, to a lesser extent, proline are used for osmoprotection under salt stress. MGG is not part of the cell strategy for coping with heat or oxidative stress. Nevertheless, MGG was an efficient protector of pig heart malate dehydrogenase against heat inactivation and freeze‐drying, although mannosylglycerate was better. This is the first report on the occurrence of MGG in living systems.
Single nucleotide polymorphisms in mannan‐binding lectins and ficolins in various strains of mice
Authors: Phaneuf L. R. , Lillie B. N. , Hayes M. A. , Turner P. V.
Published: May 2007

Mannan‐binding lectin (MBL) and ficolin are collagenous lectins produced primarily by the liver and are involved in innate resistance to microbial pathogens. Mice have two MBL genes (Mbl1 and Mbl2) that encode MBL‐A and MBL‐C, respectively. Similarly, the murine Fcna and Fcnb genes encode ficolin‐A and ficolin‐B. Several single nucleotide polymorphisms (SNP) in the human MBL2 gene are responsible for various innate immune dysfunctions due to abnormal structure or expression of human MBL‐C. In these studies, we identified SNPs in the expressed collagenous lectin genes Mbl1, Mbl2, Fcna, and Fcnb in 10 strains of mice designated high priority Group A strains by the Mouse Phenome Project (129S1/SvImJ, A/J, BALB/cByJ, C3H/HeJ, C57BL/6 J, DBA/2 J, FVB/NJ, SJL/J, CAST/EiJ and SPRET/EiJ) by sequencing gene exons by reverse transcription‐polymerase chain reaction (RT‐PCR). Sequence comparisons identified a total of 15 structural SNPs in Mbl1 in two strains, 27 SNPs in Mbl2 in five strains, and 19 and 15 SNPs in Fcna and Fcnb, respectively, in two strains. Two non‐synonymous SNPs were identified in the collagen‐like domain of mouse Fcnb that are similar to the coding polymorphisms in the collagen‐like domain of human MBL2. Most of the non‐synonymous SNPs identified in Mbl1 and Mbl2 occurred in the carbohydrate‐recognition domains (CRDs), and some resulted in altered residues close to known ligand binding sites. Similarly, most non‐synonymous SNPs of Fcna and Fcnb were identified in the fibrinogen‐like CRD. The miscoding SNPs found in the CRD regions of mouse Mbl1, Mbl2, Fcna and Fcnb may be associated with strain differences in glycan binding avidity and disposition of microbial or host ligands. Furthermore, the non‐synonymous mutations in the collagen‐like domain of Fcnb may alter the structure of the mature ficolin‐B protein leading to functional deficiencies. These differences may be important in the pathogenesis of susceptibility differences between inbred strains to various infectious microorganisms.
A method for the direct determination of the surface gravities of transiting extrasolar planets
Authors: Southworth John , Wheatley Peter J. , Sams Giles
Published: May 2007

We show that the surface gravity of a transiting extrasolar planet can be calculated from only the spectroscopic orbit of its parent star and the analysis of its transit light curve. This does not require additional constraints, such as are often inferred from theoretical stellar models or model atmospheres. The surface gravity of the planet can therefore be measured precisely and from only directly observable quantities. We outline the method and apply it to the case of the first known transiting extrasolar planet, HD 209458b. We find a surface gravity of gp= 9.28 ± 0.15 m s−2, which is an order of magnitude more precise than the best available measurements of its mass, radius and density. This confirms that the planet has a much lower surface gravity than that predicted by published theoretical models of gas giant planets. We apply our method to all 14 known transiting extrasolar planets and find a significant correlation between surface gravity and orbital period, which is related to the known correlation between mass and period. This correlation may be the underlying effect as surface gravity is a fundamental parameter in the evaporation of planetary atmospheres.
New Perspectives on the Correlation of SAT Scores, High School Grades, and Socioeconomic Factors
Authors: Zwick Rebecca , Greif Green Jennifer
Published: May 2007

In studies of the SAT, correlations of SAT scores, high school grades, and socioeconomic factors (SES) are usually obtained using a university as the unit of analysis. This approach obscures an important structural aspect of the data: The high school grades received by a given institution come from a large number of high schools, all of which have potentially different grading standards. SAT scores, on the other hand, can be assumed to have the same meaning across high schools. Our analyses of a large national sample show that, when pooled within‐high‐school analyses are applied, high school grades and class rank have larger correlations with family income and education than is evident in the results of typical analyses, and SAT scores have smaller associations with socioeconomic factors. SAT scores and high school grades, therefore, have more similar associations with SES than they do when only the usual across‐high‐school correlations are considered.
Looking Beyond the Overall Scores of NAEP Assessments: Applications of Generalized Linear Mixed Modeling for Exploring Value‐Added Item Difficulty Effects
Authors: Prowker Adam , Camilli Gregory
Published: May 2007

The central idea of differential item functioning (DIF) is to examine differences between two groups at the item level while controlling for overall proficiency. This approach is useful for examining hypotheses at a finer‐grain level than are permitted by a total test score. The methodology proposed in this paper is also aimed at estimating differences at the item rather than the overall score level, yet with the innovation where item‐level differences for many groups simultaneously are the focus. This is a straightforward generalization of DIF as variance rather than one or several group differences; conceptually, this can be referred to as item difficulty variation (IDV). When instruction is of interest, and “groups” is a unit at which instruction is determined or delivered, then IDV signals value‐added effects that can be influenced by either demographic or instructional variables.
PHYSICOCHEMICAL AND SENSORY PROPERTIES OF TOFU PREPARED WITH HEAT‐TREATED SOYBEANS
Authors: YOON HYE HYUN , KIM MEERA
Published: May 2007

The sensory characteristics of tofu made from soybeans (var. TaeKwang) heat treated at 60C for 60, 120 and 180 min were investigated to determine the effects of heat shock on the texture and flavor of tofu, which play an important role in consumer preference. Hardness and chewiness increased with heat treatment, reaching maxima at 120 min, while cohesiveness decreased significantly with heat treatment in the 120 min sample. Sensory evaluation showed that the smoothness and homogeneity of the surface of the tofu increased with heat treatment from those of the control. Grassy aroma, which is one of the main undesirable flavors of tofu, was decreased by the heat treatment. Firmness and elasticity both had a maximum value of 8.4 by the 15‐cm line‐scale evaluation in the 120 min treated samples, showing the practical possibility of using mild heat treatment to produce firm and elastic tofu. Increases in the 7S globulin due to heat treatment are thought to be responsible for the textural changes observed.

PRACTICAL APPLICATIONS

Texture and flavor are major factors in determining the quality of tofu. Tofu has become popular as a healthy food and its consumption is increasing, hence the necessity of producing tofu with various kinds of texture. We found that heat treatment on soybean used in tofu preparation can be one of the methods to control the texture of tofu. The grassy flavor of soy products is the limiting factor that seriously affects their consumption. According to our sensory evaluation, the grassy aroma was decreased significantly by heat treatment, showing that controlled heat treatment has a positive effect on the overall quality of tofu. This study suggests that heat treatment of soybeans can be applied to produce tofu with less grassy flavor and firmer texture.
EFFECTS OF BIOPOLYMER ADDITION ON THE DYNAMIC RHEOLOGY AND MICROSTRUCTURE OF RENNETED SKIM MILK SYSTEMS
Authors: TAN Y.L. , YE A. , SINGH H. , HEMAR Y.
Published: May 2007

The influence of κ‐carrageenan, xanthan gum, guar gum, high‐methoxyl (HM) pectin and gelatin addition on the rheological and microstructural properties of rennet‐induced skim milk gels was investigated using a stress‐controlled rheometer, syneresis measurement and confocal laser scanning microscopy. The elasticity, aggregation and gelation times of renneted skim milk decreased with increasing amounts of added κ‐carrageenan, xanthan gum and guar gum, whereas they increased with increasing amounts of added HM pectin and gelatin. Syneresis of the rennet‐induced skim milk gels decreased when HM pectin and gelatin were added, but increased when κ‐carrageenan, xanthan gum and guar gum were added. The changes in the viscoelastic properties and syneresis of renneted skim milk were attributed to the change in the microstructure of the rennet‐induced skim milk gel after the addition of the biopolymers. The branched protein network structure of the rennet‐induced skim milk gel could not be formed in the presence of high concentrations of xanthan gum, κ‐carrageenan and guar gum because of the formation of large protein aggregates or an open network structure with large voids.

PRACTICAL APPLICATIONS

There has been a steady growth in cheese sales over the last decade, mainly because of the increased use of cheese as an ingredient in a number of prepared foods, in which the cheese is used to add taste, texture and nutritional quality. However, because of the high cost associated with natural cheese production and storage, as well as its functional variability, the dairy industry has been aggressively seeking alternatives. Polysaccharides are used extensively in a variety of commercial dairy products as stabilizers and thickening or gelling agents. Furthermore, the use of polysaccharides is an attractive route to cost reduction in dairy products. However, as demonstrated in the present study, under certain conditions of biopolymer concentration, e.g., the use of some polysaccharides in cheese making can result in a decrease in the gel strength and whey holding ability of the cheese. Thus, avoiding the use of polysaccharides, which are known to phase separate when mixed with milk proteins, is highly recommended.
What help do young women want in their efforts to control their weight? Implications for program development
Authors: CRAWFORD David , BALL Kylie
Published: May 2007

The aim of this study was to examine women's views on the usefulness of various types of information and practical sessions on weight control, their preferences for program delivery, and likelihood of participation. Cross‐sectional survey of 462 women aged 18–33 years randomly selected from the community was conducted. We examined the perceived usefulness of various types of information and practical classes on weight control; preferred mode of delivery; willingness to participate. Among the women 82% were interested in trying to lose or control weight. Information on weight control was considered to be more useful than practical sessions. Information about meal planning, cooking and low‐fat recipes and how to manage stress was considered most useful. Fifty‐eight per cent of women reported they would prefer to participate in an individual face‐to‐face program delivered by a health professional. Thirty‐one per cent of women reported it was very likely that they would participate in a program if it included the sort of things they considered useful and was offered in the way they preferred; a further 35% felt it ‘likely’. It appears that health professional‐delivered, individual, information‐based programs appear most popular among this target group. Tailoring the content and delivery mode of weight management programs to young women's preferences may enhance program participation.
Breastfeeding: The neglected guideline for future Dietitian‐Nutritionists?
Authors: PAYNE Jan , RADCLIFFE Barbara , BLANK Emma , CHURCHILL Elizabeth , HASSAN Nadia , COX Elizabeth , PORTEOUS Helen
Published: May 2007

The objective of the present study is to determine the knowledge, attitudes and beliefs regarding breastfeeding of final‐year nutrition and dietetic students. A cross‐sectional survey of final‐year nutrition and dietetic students at a leading Australian university was conducted using an emailed questionnaire of 50 multiple‐choice questions on knowledge, attitudes, beliefs and future intentions to support and promote breastfeeding. The frequency of response to all questions was determined. Twenty‐seven of the 38 eligible students completed the survey. Significant deficits were identified relating to breastfeeding knowledge. Ninety‐two per cent of respondents reported a future intention to breastfeed or support their partner to do so; yet 69% felt bottle feeding was more socially acceptable and 23% believed that using artificial formula was easier for the mother. Although 85% of respondents believed they could influence breastfeeding initiation and duration rates, no students perceived that their studies had provided a significant amount of information on this subject, while only 8% of respondents had a strong interest in work relating to breastfeeding in the future. Improvements in the curriculum in this context may be required to ensure new graduates have the appropriate knowledge and are motivated to take positive action so that breastfeeding is properly supported. Further research is needed to determine if this issue applies in other nutrition courses and to assess the need to adopt an industry position paper on breastfeeding and associated competency standards for vocational training.
Adequacy of essential fatty acid, vitamin D and vitamin E intake: Implications for the ‘core’ and ‘extras’ food group concept of the Australian Guide to Healthy Eating
Authors: SHRAPNEL Bill , BAGHURST Katrine
Published: May 2007

Objective:  To assess the implications of new recommendations for essential fatty acids, vitamin D and vitamin E on the classification of margarines and vegetable oils as ‘extras’ in the current Australian Guide to Healthy Eating.

Design:  The role of margarines and vegetable oils as sources of essential fatty acids, vitamin D and vitamin E was examined in two ways. First, data from the 1995 National Nutrition Survey were assessed and, second, sample diets conforming to the Australian Guide to Healthy Eating were modelled and analysed.

Subjects:  For the assessment of national intake, subjects were a representative sample of 13 858 Australians, surveyed in the 1995 National Nutrition Survey.

Main outcome measures:  Relative contributions of margarines and oils, the ‘core’ food groups and ‘extras’ categories of the Australian Guide to Healthy Eating to intakes of essential fatty acids and vitamins D and E; changes in nutrient profiles of baseline diets conforming to the Australian Guide to Healthy Eating with or without varying amounts of margarines and oils.

Results:  ‘Core’ foods and ‘extras’ contributed similar amounts of essential fatty acids and vitamins D and E to the Australian diet, margarines and oils being the major contributor among ‘extras’. The simulated low‐fat, low‐saturated‐fat baseline diets generally failed to meet the adequate intakes for n‐3 and n‐6 polyunsaturates and vitamin D, and vitamin E in some instances. The addition of 25 g of sunflower margarine, but not comparable amounts of canola margarine, olive oil and butter, markedly increased the ratio of polyunsaturated to saturated fatty acids and generally delivered the adequate intakes, vitamin D being the exception.

Conclusion:  The inclusion of margarines and vegetable oils in diets based on the current Australian Guide to Healthy Eating, and guidance on choice among these foods, is required to provide adequate intakes of linoleic acid, α‐linolenic acid and vitamins D and E and to achieve fatty acid profiles consistent with the prevention of chronic disease.
Quantitative and qualitative adaptation of human skeletal muscle mitochondria to hypoxic compared with normoxic training at the same relative work rate
Authors: Bakkman L. , Sahlin K. , Holmberg H.‐C. , Tonkonogi M.
Published: May 2007

Aim:  To investigate if training during hypoxia (H) improves the adaptation of muscle oxidative function compared with normoxic (N) training performed at the same relative intensity.

Method:  Eight untrained volunteers performed one‐legged cycle training during 4 weeks in a low‐pressure chamber. One leg was trained under N conditions and the other leg under hypobaric hypoxia (526 mmHg) at the same relative intensity as during N (65% of maximal power output, Wmax). Muscle biopsies were taken from vastus lateralis before and after the training period. Muscle samples were analysed for the activities of oxidative enzymes [citrate synthase (CS) and cytochrome c oxidase (COX)] and mitochondrial respiratory function.

Results:  W
max increased with more than 30% over the training period during both N and H. CS activity increased significantly after training during N conditions (+20.8%, P < 0.05) but remained unchanged after H training (+4.5%, ns) with a significant difference between conditions (P < 0.05 H vs. N). COX activity was not significantly changed by training and was not different between exercise conditions [+14.6 (N) vs. −2.3% (H), ns]. Maximal ADP stimulated respiration (state 3) expressed per weight of muscle tended to increase after N (+31.2%, P < 0.08) but not after H training (+3.2%, ns). No changes were found in state four respiration, respiratory control index, P/O ratio, mitochondrial Ca2+ resistance and apparent Km for oxygen.

Conclusion:  The training‐induced increase in muscle oxidative function observed during N was abolished during H. Altitude training may thus be disadvantageous for adaptation of muscle oxidative function.