bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of topical PUVA soaks for palmoplantar dermatoses: an audit
Authors: O'Kane Donal , Mary McLoone Nabla , Jenkinson Hilary , Alderdice David , Badri Motasim
Published: November 2008

Background: With a lack of evidence base for individual topical PUVA protocols, treatment is presently based on the consensus of current practice. This audit was designed to investigate the effectiveness of topical PUVA for palmoplantar dermatoses.

Methods: Phototherapy notes were reviewed on all patients who received hand and/or foot PUVA 2002–2007 in the Northern Health and Social Care Trust (NHSCT), Northern Ireland.

Results: Thirty patients met the inclusion criteria for the study. The mean number of treatments, maximum single UVA dose, and cumulative dose, were 18.4, 4.2 J/cm2, and 48.3 J/cm2, respectively. A positive response to treatment occurred in 51.3% of patients, which fell short of the 70% standard set. In a multivariate logistic regression analysis, number of treatments (P=0.04) and maximum single UVA dose (P=0.03) were the only variables associated with positive treatment outcome. The response was not influenced significantly by skin type, concurrent topical treatments, or cumulative UVA dose.

Limitations to the study: Small patient numbers may have prevented the statistical significance of individual variables.

Conclusions: UV dose increments should be clearly defined to avoid excess caution at the expense of an adequate patient response, and a minimum of 20 treatments administered to all patients, if tolerated.
Cutaneous photodamage in schizophrenia patients
Authors: Wohl Yonit , Aviv Alex , Friedman Tal , Barak Yoram
Published: November 2008

Background: Schizophrenia patients frequently engage in unhealthy lifestyle behaviors. The adverse effects of sun exposure on the human skin are well studied but only sparse data in this area have been focused on schizophrenia patients.

Aim: To assess the role of sun exposure and its effects on cutaneous photoaging in schizophrenia patients compared with age‐matched healthy subjects.

Method: Skin photoaging was assessed using a modification of Glogau's classification. We developed a rating for aged appearance, applied to facial skin, dorsal hand skin, and a total integrated score. The extent of photodamage was independently evaluated by two of the investigators certified in dermatology and plastic surgery. Each rater independently estimated the subjects' age. Raters were blinded to the subjects' demographic and clinical parameters as well as to each other's ratings.

Results: Seventy‐four participants were enrolled. There were 37 patients, 24 men and 13 women, mean age: 42.7±9.7 years. The comparison group consisted of 20 men and 17 women, mean age: 42.4±9.2 years. Age, gender and BMI as well as smoking status did not differ significantly between groups. The variables found to differentiate between groups were: sun exposure, use of sunscreens, overall pigmentary changes, periorbital wrinkles and the intake of concurrent medications.

Conclusion: Increased cutaneous photoaging in schizophrenia patients, evidenced by reduced sun safety behaviors, and objective clinical signs of skin photodamage were demonstrated in the present study. We suggest that preventive measures like sun safety education should be undertaken by mental health professionals.
Solar urticaria treated successfully with intravenous high‐dose immunoglobulin: a case report
Authors: Correia Isabel , Silva João , Filipe Paulo , Gomes Manuel
Published: November 2008

Solar urticaria is an idiopathic, chronic and rare photodermatosis, characterized by the sudden onset of pruritic urticarial hives and plaques on the exposed areas of the skin, after a brief period of exposure to the natural sunlight or to an artificial light source. A Caucasian 27‐year‐old man presented with clinical features suggestive of solar urticaria was referred to our photodermatology unit, where phototesting confirmed the diagnosis of solar urticaria induced by visible light. As he was refractory to oral antihistamines and had slight improvement under UVA plus visible phototherapy, human high‐dose intravenous immunoglobulin was administered, with an excellent clinical‐sustained response.
Recent Developments in Early Modern English Life Writing and Romance
Authors: Eckerle Julie A.
Published: November 2008

Recent trends in autobiographical studies have highlighted the generic fluidity and complexity of much autobiographical expression, especially that written in 16th‐ and 17th‐century England. This essay traces a particular focus within this more general trend by examining recent considerations of how the romance genre offered a form as well as a model for much life writing during this period, especially life writing by women. This scholarship complicates assumptions about a rigid separation between private and public spheres in early modern England and about the role of religious discourse in early modern women's life writing. Certainly, spiritual discourses influenced women at this time in powerful and complex ways, and they offered a valuable and socially sanctioned means of self‐exploration, but they did not exist in a vacuum; more accurate analyses of early modern women's selves attend to the conjunction of both spiritual and secular discourses in an individual's self‐construction. Romance is one of the most important of these secular generic influences.
Transcendentalism and Religion: The State of Play
Authors: Van Anglen K. P.
Published: November 2008

This essay surveys the scholarship on American Transcendentalism for the last fifty years, focusing on its treatment of the place of religion in the movement. It finds that after an initial period when interest in religion, defined in terms of the history of ideas and institutions, was high, the 1970s and 1980s saw a neglect or exclusion of religion as a factor in Transcendentalism. More recently, there has been a resurgence of interest, however, with emphasis on such topics as spirituality and multiculturalism.
Interactions between coenzyme B12 analogs and adenosylcobalamin‐dependent glutamate mutase from Clostridium tetanomorphum
Authors: Chen Hao‐Ping , Hsu Huei‐Ju , Hsu Fang‐Ciao , Lai Chien‐Chen , Hsu Chung‐Hua
Published: November 2008

Adenosylcobalamin (AdoCbl)‐dependent glutamate mutase from Clostridium tetanomorphum comprises two weakly‐associating subunits, MutS and MutE, which combine with AdoCbl to form the active holo‐enzyme. Three coenzyme analogs, methylcobinamide (MeCbi), adenosylcobinamide (AdoCbi) and adeosylcobinamide‐GDP (AdoCbi‐GDP), were synthesized at milligram scale. Equilibrium dialysis was used to measure the binding of coenzyme B12 analogs to glutamate mutase. Our results show that, unlike AdoCbl‐dependent methylmalonyl CoA mutase, the ratio kcat/Km decreased approximately 104‐fold in both cases when AdoCbi or AdoCbi‐GDP was used as the cofactor. The coenzyme analog‐binding studies show that, in the absence of the ribonucleotide tail of AdoCbl, the enzyme's active site cannot correctly accommodate the coenzyme analog AdoCbi. The results presented here shed some light on the cobalt–carbon cleavage mechanism of B12.
PTPN22 allele polymorphisms in 15 Chinese populations
Authors: Zhang Z.‐H. , Chen F. , Zhang X.‐L. , Jin Y. , Bai J. , Fu S.‐B.
Published: November 2008

Protein tyrosine phosphatase non‐receptor 22 (PTPN22) is involved in the negative regulation of T‐cell responsiveness. Recently, it has been reported that a single nucleotide polymorphism (SNP), C1858T, in the gene PTPN22, encoding Arg620Trp in the lymphoid protein tyrosine phosphatase (LYP), is associated with an increased risk of a number of autoimmune diseases. To study the mutant frequency and polymorphism of PTPN22 in Chinese populations, 1085 individuals from 15 Chinese populations distributing widely from north to south were collected. The genotypes of PTPN22‐C1858T were determined by polymerase chain reaction‐restriction fragment length polymorphism with the digestion of restriction endonuclease RsaI. Of the 1085 individuals, 31 of whom were heterozygote (PTPN22‐1858C/T), the frequency of PTPN22‐1858T allele in those tested individuals was 1.43%. Moreover, the frequencies of PTPN22‐1858T had significant variance in 15 populations of China (χ2 = 74.1650, P < 0.01).
Impact of genetic variants of CD14 and TLR4 on subgingival periodontopathogens
Authors: Schulz S. , Zissler N. , Altermann W. , Klapproth J. , Zimmermann U. , Gläser C. , Schaller H.‐G. , Reichert S.
Published: November 2008

CD14 and toll‐like receptor 4 (TLR4) are involved in host's immune response to bacterial pathogens including periodontal bacteria. Functional important gene polymorphisms are described for both genes. The aim of this study was to evaluate links between genetic polymorphisms of CD14 and TLR4 and risk markers of periodontitis in a multivariate model. One hundred and thirty‐three periodontitis patients (chronic: n = 60, aggressive: n = 73) and 80 healthy controls without periodontitis were included in the study. Polymorphisms in CD14 c.–159C>T and in TLR4 Asp299Gly, Thr399Ile were determined by restriction fragment length polymorphism analyses. The clinical investigation included smoking status, plaque and bleeding indexes, pocket depth and attachment loss. Subgingival bacterial colonization was analysed molecularbiologically using the micro‐Ident®test. Prevotella intermedia occurred less frequently in individuals positive for the TT genotype of CD14 in bivariate analysis (odds ratio = 0.36%, confidence interval: 0.14–0.91, P = 0.045). In binary logistic regression analyses, the occurrence of this bacterium was significantly decreased in TT carriers (odds ratio = 0.31%, confidence interval: 0.81–0.12, P = 0.017) considering age, smoking and maximum clinical attachment loss at microbial test site as confounding factors. However, no significant association with chronic and or aggressive periodontitis and polymorphisms in CD14 and TLR4 could be proven. Although the CD14 c.–159C>T polymorphism could be shown to be associated with subgingival colonization with P. intermedia, there is no evidence that CD14 and TLR4 polymorphisms investigated are independent risk factors for chronic or aggressive periodontitis in German periodontitis patients.
The Swift capture of a long X-ray burst from XTE J1701-407
Authors: Linares Manuel , Watts Anna L. , Wijnands Rudy , Soleri Paolo , Degenaar Nathalie , Curran Peter A. , Starling Rhaana L. C. , Van Der Klis Michiel
Published: November 2008

XTE J1701−407 is a new transient X-ray source discovered on 2008 June 8. More than one month later, it showed a rare type of thermonuclear explosion: a long type I X-ray burst. We report herein the results of our study of the spectral and flux evolution during this burst, as well as the analysis of the outburst in which it took place. We find an upper limit on the distance to the source of 6.1 kpc by considering the maximum luminosity reached by the burst. We measure a total fluence of 3.5 × 10−6 erg cm−2 throughout the ∼20 min burst duration and a fluence of 2.6 × 10−3 erg cm−2 during the first two months of the outburst. We show that the flux decay is best fitted by a power law (index ∼1.6) along the tail of the burst. Finally, we discuss the implications of the long burst properties, and the presence of a second and shorter burst detected by Swift ten days later, for the composition of the accreted material and the heating of the burning layer.
Implementing a Method of Screening One‐Well Hydraulic Barrier Design Alternatives
Authors: Rubin Hillel , Shoemaker Christine A , Köngeter Jürgen
Published: November 2008

This article provides details of applying the method developed by the authors (Rubin et al. 2008b) for screening one‐well hydraulic barrier design alternatives. The present article with its supporting information (manual and electronic spreadsheets with a case history example) provides the reader complete details and examples of solving the set of nonlinear equations developed by Rubin et al. (2008b). It allows proper use of the analytical solutions and also depicting the various charts given by Rubin et al. (2008b). The final outputs of the calculations are the required position and the discharge of the pumping well. If the contaminant source is nonaqueous phase liquid (NAPL) entrapped within the aquifer, then the method provides an estimate of the aquifer remediation progress (which is a by‐product) due to operating the hydraulic barrier.
PRICE‐SETTING BEHAVIOR IN TURKISH INDUSTRIES: EVIDENCE FROM SURVEY DATA
Authors: ŞAHİNÖZ Saygın , SARAÇOĞLU Bedri̇ye
Published: November 2008

This study investigates the price‐setting behavior of Turkish industries based on the results of a survey that was conducted by the Central Bank of the Republic of Turkey. The results show that, under normal conditions, the majority of the firms follow a time‐dependent pricing rule but when significant events occur a substantial fraction of them alter their behavior to state‐dependent reviewing. The median Turkish firm reviews its prices every month, but changes its prices four times a year. Price reviews and changes are affected by: the market share, price discrimination, customer type, firm size, and the existence of regulated prices.
Human rights in times of terror – a judicial point of view
Authors: Barak Aharon
Published: November 2008

This paper, delivered as the Second Scarman lecture, argues that the role of a judge on the Supreme Court of a democratic state is to protect both the constitution and the democracy. Judges in modern democracies should protect democracy both from terrorism and from the means the state wishes to use to fight terrorism. Judges meet their supreme test when they face situations of war and terrorism. The protection of human rights of every individual is a duty much more formidable in situations of war or terrorism than in times of peace and security. But if judges fail in their role in times of war and terrorism, they will be unable to fulfil their role in times of peace and tranquility. It is a myth to think that it is possible to maintain a sharp distinction between the status of human rights during a period of war and the status of human rights during a period of peace. The paper explores these issues through an examination of the need for a balanced and proportionate approach and by using illustrations from the example of the Israeli Supreme Court, with a focus on the role of judicial review in the ‘war on terror’.
Singapore's electoral system: government by the people?
Authors: Tey Tsun Hang
Published: November 2008

Singapore's Westminster parliamentary system of government was adopted as a historical result of it being a British colony. In its post-independence constitutional development, the dominant People's Action Party political leadership had made a series of constitutional amendments to its original electoral system, introducing innovative schemes such as Group Representation Constituencies, Non-Constituency Members of Parliament, Nominated Members of Parliament and the Elected Presidency. These changes have resulted in an electoral system that is so different and divergent from the Westminster model that it should be regarded a unique regime of its own. This paper advances the view that the constitutional evolution of its electoral system is reflective of a political vision structured along elitist lines – underscored by a desire to restructure the voting behaviour of its citizens, and ensure predictability and the preservation of the status quo. It has been driven by paternalistic assumptions about what is beneficial for its citizens. This paper examines the subsequent implementation of the schemes, before reflecting on how it is a system that has the potential to affect adversely the development of political participation and political pluralism, and dilute democratic politics in Singapore.
Relatives’ experiences of encountering the older person with acute confusional state: experiencing unfamiliarity in a familiar person
Authors: Stenwall Ewa , Sandberg Jonas , Eriksdotter Jönhagen Maria , Fagerberg Ingegerd
Published: November 2008

Aims and objectives.  The aim was to understand the lived experience of close relatives encountering older persons with acute confusional state.

Background.  Little is known about relatives of patients with acute confusional state and their experiences while encountering a family member exhibiting acute confusional state.

Design.  A descriptive phenomenological research approach was used.

Methods.  Data were collected by interviewing 10 close relatives of older people with acute confusional state at two hospital wards.

Results.  Relatives experience the encounter as encountering a familiar person who has suddenly become unfamiliar, struggling to separate the familiar from the unfamiliar and trying to understand the causes of acute confusional state and the behaviour of the person. Six constituents illuminate the phenomenon: ‘change in the other person’, ‘rapid and unexpected changes’, ‘experiencing insecurity in the encounter’, ‘trusting or mistrusting the other person’, ‘experiencing loss’ and ‘experiencing exposure’.

Relevance to clinical practice.  It is important for professional carers to support relatives on how to encounter the person with acute confusional state, and to co‐operate with relatives to gain knowledge about the unique person behind the acute confusional state.

Conclusion.  Relatives’ difficulties in dealing with strong emotions evoked within the encounter, experiencing limitation and lack of trust is essential knowledge for professional carers in all care settings.
The reliability of the Hendrich Fall Risk Model in a geriatric hospital
Authors: Heinze Cornelia , Halfens Ruud , Dassen Theo
Published: November 2008

Aims and objectives.  The purpose of this study was to test the interrater reliability of the Hendrich Fall Risk Model, an instrument to identify patients in a hospital setting with a high risk of falling.

Background.  Falls are a serious problem in older patients. Valid and reliable fall risk assessment tools are required to identify high‐risk patients and to take adequate preventive measures.

Methods.  Seventy older patients were independently and simultaneously assessed by six pairs of raters made up of nursing staff members. Consensus estimates were calculated using simple percentage agreement and consistency estimates using Spearman’s rho and intra class coefficient.

Results.  Percentage agreement ranged from 0.70 to 0.92 between the six pairs of raters. Spearman’s rho coefficients were between 0.54 and 0.80 and the intra class coefficients were between 0.46 and 0.92.

Conclusions.  Whereas some pairs of raters obtained considerable interobserver agreement and internal consistency, the others did not. Therefore, it is concluded that the Hendrich Fall Risk Model is not a reliable instrument. The use of more unambiguous operationalized items is preferred.

Relevance to clinical practice.  In practice, well operationalized fall risk assessment tools are necessary. Observer agreement should always be investigated after introducing a standardized measurement tool.
Using relationships to develop practice that values the contribution of older people, families and staff
Authors: Wilson Christine Brown
Published: November 2008

Relationships between staff, residents and their families have emerged within the literature as fundamental to the experiences of life within the community of a care home. While there is consensus in the literature that such relationships are central to caring processes, there is a dearth of studies that have explained how different factors contribute to the formation of relationships. The research reported here aims to describe the nature of relationships and develop an interpretive framework to understand how relationships influence the experience of residents, families and staff in care homes.

This paper is based on the findings from a constructivist inquiry. Data were collected in three care homes using participant observation, interviews and focus groups with older people, families and staff. Constructivist methodology seeks to share multiple perceptions between participants with the aim of creating a joint construction. This process, known as the hermeneutic dialectic supported the development of shared meanings as views and ideas were shared between participants. The findings suggested that three types of relationships are developed within care homes: pragmatic; personal and responsive and reciprocal. These relationships are influenced by a range of factors that include leadership, team working and the contributions made by residents, families and staff.
The Norwegian teaching home program: developing a model for systematic practice development in the nursing home sector
Authors: Kirkevold Marit
Published: November 2008

Background.  In the mid‐1990s, there was persistent critique of the quality of care provided in residential aged care facilities in Norway, in line with similar concerns expressed in many other countries. Difficulties recruiting qualified staff and high turnover led to difficult working conditions. Little prestige was associated with providing geriatric care. Collaboration between educational institutions, universities and elderly care institutions with the purpose of strengthening education, competence development, practice development and research within elderly care was poorly developed. The Norwegian teaching nursing home (NTNH) program was launched to address these issues.

Aim.  The purpose of the NTNH was to contribute to the quality of care of frail older persons by improving the competence of staff, improving the prestige of working with older people, stimulating development of services, facilitating research into the care of older persons, and developing good learning environments for students.

Methods.  The NTNH‐program was developed over a period of seven years, applying a participatory action research design. Progressing through four phases, it involved a number of people and institutions across Norway.

Results.  Formal and informal competence of staff was increased. A large number of practice development projects contributed to increased quality of care in selected problem areas. Models of competence development were disseminated to other institutions, thereby improving the level of competence beyond the NTNHs. Learning conditions for students were improved. Following a formal evaluation of the program, teaching nursing homes (TNHs) were established on a permanent basis in 2004, with financial support from the Department of Health and Social Services. In 2008, a total of 20 TNHs are part of the NTNH program.

Conclusions.  The NTNH program led to permanent establishment of a series of TNHs responsible for contributing to competence development, practice development and research on a continuous basis in order to secure high levels of care to the Norwegian nursing home population. The program has created substantial enthusiasm within the nursing home sector and has increased the prestige of these institutions.
Calling for an international dialogue on quality of life in care homes
Authors: Meyer Julienne , Owen Tom
Published: November 2008

meyer j. & owen t. (2008) International Journal of Older People Nursing 3, 291–294 Calling for an international dialogue on quality of life in care homes
Microsatellite loci characterized in three African crane species (Gruidae, Aves)
Authors: MEARES KATE , DAWSON DEBORAH A. , HORSBURGH GAVIN J. , GLENN TRAVIS C. , JONES KENNETH L. , BRAUN MICHAEL J. , PERRIN MIKE R. , TAYLOR TIAWANNA D.
Published: November 2008

Forty‐three microsatellite loci originally isolated in Grus americana and G. japonensis were tested for polymorphism in the blue crane (G. paradisea). Amplified products were sequenced in the blue crane to aid in the design of blue crane‐specific primers. When characterized in 20 unrelated blue crane individuals from South Africa, 14 loci were polymorphic, with each locus displaying between 2 and 7 alleles. Eight polymorphic loci were characterized in the grey‐crowned crane (Balearica regulorum) and ten in the wattled crane (G. carunculatus).
Going for Gold, from Beijing to Munich, Highlights from the ESC 2008 Congress: BEAUTIFUL, GISSI‐HF, and Potential New Therapies for Acute Decompensated Heart Failure
Authors: Kalra Paul , Pauriah Maheshwar , Elder D. , Lang Chim C.
Published: November 2008

Formerly Cardiovascular Drug Reviews

http://www.blackwellpublishing.com/CATH
Short‐Term Effect of Atorvastatin on Endothelial Function in Healthy Offspring of Parents with Type 2 Diabetes Mellitus
Authors: Amudha Kadirvelu , Choy Anna Maria , Mustafa Mohamed R. , Lang Chim C.
Published: November 2008

Endothelial function is impaired in healthy subjects at risk of type 2 diabetes mellitus (DM). We investigated whether endothelial dysfunction can be normalized by statin therapy in this potentially predisposed population. Flow‐mediated dilation (FMD) was measured in 56 first‐degree relatives (FDRs) (normotensive, normal glucose tolerance) and 20 age‐, sex‐, and BMI‐matched controls with no family history of DM. Other measurements included insulin resistance index using the homeostasis model of insulin resistance (HOMAIR), plasma lipids, and markers of inflammation. The FDRs were then randomized and treated with atorvastatin (80 mg) or placebo daily in a 4‐week double‐blind, placebo‐controlled trial. The FDRs had significantly impaired FMD (4.4 ± 8.1% vs. 13.0 ± 4.2%; P < 0.001), higher HOMAIR (1.72 ± 1.45 vs. 1.25 ± 0.43; P= 0.002), and elevated levels of plasma markers of inflammation—highly sensitive C‐reactive protein (hsCRP) (2.6 ± 3.8 mg/L vs. 0.7 ± 1.0 mg/L; P= 0.06), interleukin (IL)‐6 (0.07 ± 0.13 ng/mL vs. 0.03 ± 0.01 ng/mL; P < 0.001), and soluble intercellular adhesion molecule (sICAM) (267.7 ± 30.7 ng/mL vs. 238.2 ± 20.4 ng/mL; P < 0.001). FMD improved in the atorvastatin‐treated subjects when compared with the placebo‐treated subjects (atorvastatin, from 3.7 ± 8.5% to 9.8 ± 7.3%; placebo, from 3.9 ± 5.6% to 4.7 ± 4.2%; P= 0.001). There were also reductions in the levels of IL‐6 (0.08 ± 0.02 ng/mL vs. 0.04 ± 0.01 ng/mL; P < 0.001) and hsCRP (3.0 ± 3.9 mg/L vs. 1.0 ± 1.3 mg/L; P= 0.006). Our study suggests that treatment with atorvastatin may improve endothelial function and decrease levels of inflammatory markers in FDRs of type 2 DM patients.
Treatment options for postmenopausal osteoporosis in Asia
Authors: CHU Eva Yuet‐wah , TSANG Shirley Wan‐yin , KUNG Annie Wai‐chee
Published: November 2008

Treatment of osteoporosis has advanced dramatically during the past decade, with more therapeutic options than ever now available. Large‐scale randomized placebo‐controlled trials have documented the efficacy of a number of agents in reducing vertebral and non‐vertebral fractures. Anti‐resorptive agents (hormone replacement therapy, selective estrogen‐receptor modulators, calcitonin and bisphosphonates) and bone‐forming anabolic agents (parathyroid horomone and strontium ranelate) act via different mechanisms to reduce fractures and improve bone strength. In view of the high prevalence of calcium and vitamin D insufficiency in Asia, calcium and vitamin D supplementation remains a fundamental part of any treatment regimen, especially among the elderly. Given the high cost of these agents, a global assessment of the fracture risk of the patient is essential to determine the need for pharmacological treatment versus life‐style modification and dietary supplementation in the management of postmenopausal osteoporosis in Asia.
Risk factors of Egyptian male osteoporosis
Authors: ELGENDI Salwa S. , RASHAD Sonya M. , MOHAMED Fatma H. , EL‐TOHAMY Wafaa M. , EL‐SHAZLY Ashraf A. , JELANY Reda M.
Published: November 2008

Background:  Osteoporosis (OP) is a growing health problem not only in women but also in men.

Subjects and methods:  This study was carried out on 100 healthy men, age range 30–65 years (mean ± SD, 44.65 ± 8.3). All were randomly recruited from Assiut city during the period January 2005 to January 2006. Complete clinical history included occupational history, smoking habit, physical activity and calcium intake. Complete clinical examination and anthropometric measurments were done. Laboratory investigations for serum calcium, phosphorus and osteocalcin were performed. Bone mineral density (BMD) was measured by calcaneal ultrasound.

Results:  Sixty‐three percent of participants had normal BMD, 37% had low BMD, (26% had quantitative bone ultrasound [QUS] T‐score –1 to –2.5 and 11% had QUS T‐score ≤ –2.5). Smoking and low physical activity were risk factors for low BMD. Significant positive correlations were found between BMD and body mass index, serum calcium, and osteocalcin and negative correlation with phosphorus. We concluded that low BMD occurs with high frequency in Egyptian men. Smoking, physical inactivity and low body index are significant risk factors. Low serum calcium, low serum osteocalcin and high serum phosphorus are biochemical risk factors of low BMD in males.
Definition of a population‐specific dual energy X‐ray absorptiometry reference standard in Isfahani women
Authors: BONAKDAR Zahra Sayed , KARIMZADEH Hadi , KARIMIFAR Mansoor , MOTTAGHI Peyman , SALESI Mansour , FARAJZADEGAN Ziba
Published: November 2008

Objective: There are some clues that correct interpretation of bone mineral density (BMD) when measured by dual‐energy X‐ray absorptiometry (DXA) which requires a population specific reference range. We determined reference values of BMD and the prevalence of osteopenia and osteoporosis in postmenopausal Isfahani women.

Methods: In this cross‐sectional study, 1118 healthy women from Isfahan, aged between 20 and 80 years were recruited door‐to‐door for research. BMD was measured at the anteroposterior lumbar spine (L2–L4) (AP) and femoral neck (FN) with the Lunar DPX‐IQ densitometer. Peak bone mass (PBM), reference curves of BMD, prevalence of osteoporosis and osteopenia were determined according to World Health Organization (WHO) criteria.

Results: In Isfahani women osteoporosis and osteopenia of the AP lumbar spine exists at BMD < 0.898 g/cm2and between 1.078 g/cm2and 0.898 g/cm2, respectively. At the FN a BMD < 0.676 g/cm2defines osteoporosis whereas osteopenia is defined as a BMD between 0.841 g/cm2and 0.676 g/cm2. The prevalence of osteoporosis and osteopenia at the AP lumbar spine in the age groups 51–55, 56–60, 61–65, 66–70, > 70 years were, 7.9%, 19.6%, 26%, 32.1%, 31.8%, and 28.9%, 36.5%, 38.4%, 41.1%, 45.5%, respectively. The prevalence of osteoporosis and osteopenia at the FN in the same age groups, were, 2.6%, 2%, 12.3%, 14.3%, 22.7% and 28.3%, 39.9%, 43.8%, 50%, 68.2%, respectively.

Conclusions: Our data would use a population‐specific reference range for DXA measurements and to estimate the prevalence of osteopenia and osteoporosis.
Nutritional regulation of glucagon‐like peptide‐1 secretion
Authors: Tolhurst Gwen , Reimann Frank , Gribble Fiona M.
Published: November 2008

Glucagon‐like peptide‐1 (GLP‐1), released from L‐cells in the intestinal epithelium, plays an important role in postprandial glucose homeostasis and appetite control. Following the recent therapeutic successes of antidiabetic drugs aimed at either mimicking GLP‐1 or preventing its degradation, attention is now turning towards the L‐cell, and addressing whether it would be both possible and beneficial to stimulate the endogenous release of GLP‐1 in vivo. Understanding the mechanisms underlying GLP‐1 release from L‐cells is key to this type of approach, and the use of cell line models has led to the identification of a variety of pathways that may underlie the physiological responses of L‐cells to food ingestion. This review focuses on our current understanding of the signalling mechanisms that underlie L‐cell nutrient responsiveness.
Neonatal Aortic Arch Hemodynamics and Perfusion During Cardiopulmonary Bypass
Authors: Pekkan Kerem , Dur Onur , Sundareswaran Kartik , Kanter Kirk , Fogel Mark , Yoganathan Ajit , Ündar Akif
Published: November 2008

The objective of this study is to quantify the detailed three-dimensional (3D) pulsatile hemodynamics, mechanical loading, and perfusion characteristics of a patient-specific neonatal aortic arch during cardiopulmonary bypass (CPB). The 3D cardiac magnetic resonance imaging (MRI) reconstruction of a pediatric patient with a normal aortic arch is modified based on clinical literature to represent the neonatal morphology and flow conditions. The anatomical dimensions are verified from several literature sources. The CPB is created virtually in the computer by clamping the ascending aorta and inserting the computer-aided design model of the 10 Fr tapered generic cannula. Pulsatile (130 bpm) 3D blood flow velocities and pressures are computed using the commercial computational fluid dynamics (CFD) software. Second order accurate CFD settings are validated against particle image velocimetry experiments in an earlier study with a complex cardiovascular unsteady benchmark. CFD results in this manuscript are further compared with the in vivo physiological CPB pressure waveforms and demonstrated excellent agreement. Cannula inlet flow waveforms are measured from in vivo PC-MRI and 3 kg piglet neonatal animal model physiological experiments, distributed equally between the head-neck vessels and the descending aorta. Neonatal 3D aortic hemodynamics is also compared with that of the pediatric and fetal aortic stages. Detailed 3D flow fields, blood damage, wall shear stress (WSS), pressure drop, perfusion, and hemodynamic parameters describing the pulsatile energetics are calculated for both the physiological neonatal aorta and for the CPB aorta assembly. The primary flow structure is the high-speed canulla jet flow (∼3.0 m/s at peak flow), which eventually stagnates at the anterior aortic arch wall and low velocity flow in the cross-clamp pouch. These structures contributed to the reduced flow pulsatility (85%), increased WSS (50%), power loss (28%), and blood damage (288%), compared with normal neonatal aortic physiology. These drastic hemodynamic differences and associated intense biophysical loading of the pathological CPB configuration necessitate urgent bioengineering improvements—in hardware design, perfusion flow waveform, and configuration. This study serves to document the baseline condition, while the methodology presented can be utilized in preliminary CPB cannula design and in optimization studies reducing animal experiments. Coupled to a lumped-parameter model the 3D hemodynamic characteristics will aid the surgical decision making process of the perfusion strategies in complex congenital heart surgeries.
Noninvasive Blood Perfusion Measurements of an Isolated Rat Liver and an Anesthetized Rat Kidney
Authors: Mudaliar Ashvinikumar V. , Ellis Brent E. , Ricketts Patricia L. , Lanz Otto I. , Lee Charles Y. , Diller Thomas E. , Scott Elaine P.
Published: November 2008

A simple, cost effective, and noninvasive blood perfusion system is tested in animal models. The system uses a small sensor to measure the heat transfer response to a thermal event (convective cooling) imposed on the tissue surface. Heat flux data are compared with a mathematical model of the tissue to estimate both blood perfusion and thermal contact resistance between the tissue and the probe. The perfusion system was evaluated for repeatability and sensitivity using isolated rat liver and exposed rat kidney tests. Perfusion in the isolated liver tests was varied by controlling the flow of the perfusate into the liver, and the perfusion in the exposed kidney tests was varied by temporarily occluding blood flow through the renal artery and vein. The perfusion estimated by the convective perfusion probe was in good agreement with that of the metered flow of the perfusate into the liver model. The liver tests indicated that the probe can be used to detect small changes in perfusion (0.005 ml/ml/s). The probe qualitatively tracked the changes in the perfusion in the kidney model due to occlusion of the renal artery and vein.
The Dynamic Mechanical Environment of the Chondrocyte: A Biphasic Finite Element Model of Cell-Matrix Interactions Under Cyclic Compressive Loading
Authors: Kim Eunjung , Guilak Farshid , Haider Mansoor A.
Published: November 2008

Cyclic mechanical loading of articular cartilage results in a complex biomechanical environment at the scale of the chondrocytes that strongly affects cellular metabolic activity. Under dynamic loading conditions, the quantitative relationships between macroscopic loading characteristics and solid and fluid mechanical variables in the local cellular environment are not well understood. In this study, an axisymmetric multiscale model of linear biphasic cell-matrix interactions in articular cartilage was developed to investigate the cellular microenvironment in an explant subjected to cyclic confined compressive loading. The model was based on the displacement-velocity-pressure (u-v-p) mixed-penalty weighted residual formulation of linear biphasic theory that was implemented in the COMSOL MULTIPHYSICS software package. The microscale cartilage environment was represented as a three-zone biphasic region consisting of a spherical chondrocyte with encapsulating pericellular matrix (PCM) that was embedded in a cylindrical extracellular matrix (ECM) subjected to cyclic confined compressive loading boundary conditions. Biphasic material properties for the chondrocyte and the PCM were chosen based on previous in vitro micropipette aspiration studies of cells or chondrons isolated from normal or osteoarthritic cartilage. Simulations performed at four loading frequencies in the range 0.01–1.0 Hz supported the hypothesized dual role of the PCM as both a protective layer for the cell and a mechanical transducer of strain. Time varying biphasic variables at the cellular scale were strongly dependent on relative magnitudes of the loading period, and the characteristic gel diffusion times for the ECM, the PCM, and the chondrocyte. The multiscale simulations also indicated that axial strain was significantly amplified in the range 0.01–1.0 Hz, with a decrease in amplification factor and frequency insensitivity at the higher frequencies. Simulations of matrix degradation due to osteoarthritis indicated that strain amplification factors were more significantly altered when loss of matrix stiffness was exclusive to the PCM. The findings of this study demonstrate the complex dependence of dynamic mechanics in the local cellular environment of cartilage on macroscopic loading features and material properties of the ECM and the chondron.
A New Method for Measuring Deformation of Folding Surfaces During Morphogenesis
Authors: Filas Benjamen A. , Knutsen Andrew K. , Bayly Philip V. , Taber Larry A.
Published: November 2008

During morphogenesis, epithelia (cell sheets) undergo complex deformations as they stretch, bend, and twist to form the embryo. Often these changes in shape create multivalued surfaces that can be problematic for strain measurements. This paper presents a method for quantifying deformation of such surfaces. The method requires four-dimensional spatiotemporal coordinates of a finite number of surface markers, acquired using standard imaging techniques. From the coordinates of the markers, various deformation measures are computed as functions of time and space using straightforward matrix algebra. This method accommodates sparse randomly scattered marker arrays, with reasonable errors in marker locations. The accuracy of the method is examined for some sample problems with exact solutions. Then, the utility of the method is illustrated by using it to measure surface stretch ratios and shear in the looping heart and developing brain of the early chick embryo. In these examples, microspheres are tracked using optical coherence tomography. This technique provides a new tool that can be used in studies of the mechanics of morphogenesis.
Surface Instability of Sheared Soft Tissues
Authors: Destrade M. , Gilchrist M. D. , Prikazchikov D. A. , Saccomandi G.
Published: November 2008

When a block made of an elastomer is subjected to a large shear, its surface remains flat. When a block of biological soft tissue is subjected to a large shear, it is likely that its surface in the plane of shear will buckle (appearance of wrinkles). One factor that distinguishes soft tissues from rubberlike solids is the presence—sometimes visible to the naked eye—of oriented collagen fiber bundles, which are stiffer than the elastin matrix into which they are embedded but are nonetheless flexible and extensible. Here we show that the simplest model of isotropic nonlinear elasticity, namely, the incompressible neo-Hookean model, suffers surface instability in shear only at tremendous amounts of shear, i.e., above 3.09, which corresponds to a 72deg angle of shear. Next we incorporate a family of parallel fibers in the model and show that the resulting solid can be either reinforced or strongly weakened with respect to surface instability, depending on the angle between the fibers and the direction of shear and depending on the ratio E∕μ between the stiffness of the fibers and that of the matrix. For this ratio we use values compatible with experimental data on soft tissues. Broadly speaking, we find that the surface becomes rapidly unstable when the shear takes place “against” the fibers and that as E∕μ increases, so does the sector of angles where early instability is expected to occur.
Numerical Approximation of Tangent Moduli for Finite Element Implementations of Nonlinear Hyperelastic Material Models
Authors: Sun Wei , Chaikof Elliot L. , Levenston Marc E.
Published: November 2008

Finite element (FE) implementations of nearly incompressible material models often employ decoupled numerical treatments of the dilatational and deviatoric parts of the deformation gradient. This treatment allows the dilatational stiffness to be handled separately to alleviate ill conditioning of the tangent stiffness matrix. However, this can lead to complex formulations of the material tangent moduli that can be difficult to implement or may require custom FE codes, thus limiting their general use. Here we present an approach, based on work by Miehe (Miehe, 1996, “Numerical Computation of Algorithmic (Consistent) Tangent Moduli in Large Strain Computational Inelasticity,” Comput. Methods Appl. Mech. Eng., 134, pp. 223–240), for an efficient numerical approximation of the tangent moduli that can be easily implemented within commercial FE codes. By perturbing the deformation gradient, the material tangent moduli from the Jaumann rate of the Kirchhoff stress are accurately approximated by a forward difference of the associated Kirchhoff stresses. The merit of this approach is that it produces a concise mathematical formulation that is not dependent on any particular material model. Consequently, once the approximation method is coded in a subroutine, it can be used for other hyperelastic material models with no modification. The implementation and accuracy of this approach is first demonstrated with a simple neo-Hookean material. Subsequently, a fiber-reinforced structural model is applied to analyze the pressure-diameter curve during blood vessel inflation. Implementation of this approach will facilitate the incorporation of novel hyperelastic material models for a soft tissue behavior into commercial FE software.
PIV Measurements of the Flow Field Just Downstream of an Oscillating Collapsible Tube
Authors: Bertram C. D. , Truong N. K. , Hall S. D.
Published: November 2008

We probed the time-varying flow field immediately downstream of a flexible tube conveying an aqueous flow, during flow-induced oscillation of small amplitude, at time-averaged Reynolds numbers (Re) in the range 300–550. Velocity vector components in the plane of a laser sheet were measured by high-speed (“time-resolved”) particle image velocimetry. The sheet was aligned alternately with both the major axis and the minor axis of the collapsing tube by rotating the pressure chamber in which the tube was mounted. The Womersley number of the oscillations was approximately 10. In the major-axis plane the flow fields were characterized by two jets that varied in lateral spacing. The rapid deceleration of flow at maximal collapse caused the jets momentarily to merge about one diameter into the downstream pipe, and strengthened and enlarged the existing retrograde flow lateral to each jet. Collapse also spread the jets maximally, allowing retrograde flow between them during the ascent from its minimum of the pressure at the end of the flexible tube. The minor-axis flow fields showed that the between-jet retrograde flow at this time extended all the way across the pipe. Whereas the retrograde flow lateral to the jets terminated within three diameters of the tube end at Re=335 at all times, it extended beyond three diameters at Re=525 for some 25% of the cycle including the time of maximal flow deceleration. Off-axis sheet positioning revealed the lateral jets to be crescent shaped. When the pressure outside the tube was increased, flattening the tube more, the jets retained a more consistent lateral position. These results illuminate the flows created by collapsible-tube oscillation in a laminar regime accessible to numerical modeling.
A Model of the Human Eye
Authors: Colicchia G. , Wiesner H. , Waltner C. , Zollman D.
Published: November 2008

We describe a model of the human eye that incorporates a variable converging lens. The model can be easily constructed by students with low-cost materials. It shows in a comprehensible way the functionality of the eye's optical system. Images of near and far objects can be focused. Also, the defects of near and farsighted eyes can be demonstrated.
The Homigrade Thermometer
Authors: Greenslade Thomas B.
Published: November 2008

In principle, designing a thermometer scale is easy. The trick lies in persuading others to use your scale. The Homigrade scale is an example of a clever and useful scale that has never caught on. Students can use it as an example of how they might set up their own arbitrary temperature scales.
Physics Lab Myths
Authors: Morrison Andrew
Published: November 2008

At the start of each semester, and especially at the beginning of a new school year, I kick off the first lab session with a pop quiz designed to engage the students in critical thinking. It provides a way to introduce to the students my philosophy of a physics laboratory experience. Once the students get over the shock of having a quiz on the first day of lab, it is hopefully a way to have a little fun, something that I hope all the students have throughout the semester.