bluuebunny/crossref_metadata_2025 huggingface dataset:
HLA‐DRB1 alleles are associated with the clinical course of disease and steroid dependence in Mexican patients with ulcerative colitis
Authors: Yamamoto‐Furusho J. K. , Rodríguez‐Bores L. , Granados J.
Published: August 2009

Aim  The aim of this study was to study the association between the HLA‐DRB1 alleles and the clinical course of ulcerative colitis (UC).

Method  Seventy‐five Mexican patients with UC were studied. High resolution HLA typing was performed using Polymerase Chain Reaction‐Sequence Specific Oligonucleotide PCR‐SSO reverse dot blot and Polymerase Chain Reaction‐single specific primer PCR‐SSP. Molecular typing techniques were applied to define HLA‐DRB1 alleles.

Results  Seventy‐five patients (36 female patients, 39 male patients) were studied. Significant associations were found between some HLA‐DRB1 alleles and the clinical course of disease: initial active and then inactive and the HLA‐DRB1*14 allele (P = 0.03; OR = 4.63; 95% CI: 1.08–21.23); and HLA‐DRB1*08 allele (P = 0.04; OR = 4.34; 95% CI: 1.9–33.3). On the other hand, the HLA‐DRB1*07 (P = 0.001; OR = 9.76 95% CI: 1.55–65.56) was significantly associated with steroid dependence in UC patients.

Conclusions  This study suggests that HLA‐DRB1 alleles were associated with the clinical course of disease and steroid dependence in UC patients.
The prognostic significance of the metastatic lymph node ratio in Dukes stage C colorectal cancer in a district general hospital
Authors: Ainsworth P. D. , Johnson M. A.
Published: August 2009

Aim  Our aim was to determine if the lymph node ratio would predict overall survival and disease‐free survival in Dukes C colorectal cancer in a district general hospital setting in the UK.

Method  Fifty‐six patients were analysed from a prospectively maintained colorectal cancer database. The lymph node ratio was defined as the number of positive lymph nodes divided by the total number of nodes harvested. Comparison was made between the lymph node ratio,TNM nodal status and number of positive lymph nodes by the Kaplan–Meier method. An analysis of covariates was performed by a Cox proportional hazard regression analysis.

Results  A lymph node ratio of > 0.25 is prognostically significant for overall survival (P = 0.03) and disease‐free survival (P = 0.0003). The lymph node ratio was the strongest covariate in the multivariate regression analysis for recurrence (P = 0.003).

Conclusion  The lymph node ratio may help clinicians determine which patients have a more aggressive tumour biology and direct appropriate more aggressive chemotherapy regimes towards these patients.
Ethnic disparity in colonic cancer outcomes in New Zealand – biology or an access issue?
Authors: Sammour T. , Kahokehr A. , Vather R. , Connolly A. B. , Hill A. G.
Published: August 2009

Background  There is an ethnic variation in outcomes for colonic cancer in New Zealand. Whether this disparity is caused by cancer biology or inequitable provision of treatment services after diagnosis has not been elucidated.

Method  National cancer registry data from 1996 to 2003 were obtained. Incidence and mortality rates for the four major ethnic groups were age‐adjusted to the new WHO world population. The impact of age, sex, AJCC stage and site of cancer at diagnosis was compared between ethnic groups using a Cox regression analysis.

Results  A total of 11 987 colonic cancer registrations were identified. The overall raw 5‐year mortality was 53.7%. The age‐adjusted incidence in Europeans was more than double that of the Maori, Asian and Pacific populations at 33.0 per 100 000 population/year. Europeans presented at a greater age, with more right sided cancers, and at an earlier stage of disease. The opposite was true for the Maori population. Pacific Islanders and Asians presented at a younger age, but with a similar site, stage and sex distribution to the rest of the population. There were no significant differences in 5 year mortality after diagnosis when age, sex, stage, and site at presentation were controlled for by cox regression analysis.

Conclusion  These results suggest that age, sex, stage and site at presentation may be more important than inequality in treatment provision after diagnosis in explaining differences in outcomes between the ethnicities. Efforts need to be focused on identifying reasons for the increased risk of colonic neoplasia in Europeans and the later stage disease presentation in the Maori population.
Street‐Level Bureaucracy, Interprofessional Relations, and Coping Mechanisms: A Study of Criminal Justice Social Workers in the Sentencing Process
Authors: HALLIDAY SIMON , BURNS NICOLA , HUTTON NEIL , MCNEILL FERGUS , TATA CYRUS
Published: August 2009

This article builds on the work of Michael Lipsky and develops an argument about the significance of interprofessional working for street‐level bureaucracy. It presents an ethnographic analysis of criminal justice social workers writing presentence reports for the Scottish courts. Social workers' report writing for judges brought into relief issues of relative professional status. Social workers were uncertain of their place within the legal domain and concerned about their credibility as criminal justice professionals. Reports were written, in part at least, as a way of seeking esteem and credibility in the eyes of judges—a motivation that undermined the policy objectives of social enquiry in sentencing. Applying the conceptual tools of Bourdieu to our findings, we argue that street‐level bureaucrats who have to work across bureaucratic “fields” may find, or fear, that the cultural and symbolic “capital” they retained within their own field is undervalued in the symbolic economy of new fields, putting them in a position of relative inferiority. This issue of relative professional status, and how officials respond to it, is significant for our understanding of street‐level bureaucracy.
Investigating Burnout and Psychological Well‐Being of Staff Working with People with Intellectual Disabilities and Challenging Behaviour: The Role of Personality
Authors: Chung Man Cheung , Harding Carly
Published: August 2009

Background  The present research extended previous research by broadening the dimensions of personality traits, and focusing on burnout and psychological well‐being among staff working with people with intellectual disabilities and challenging behaviour.

Methods  This is a cross‐sectional survey in which 103 staff completed questionnaires measuring clients’ challenging behaviour according to staff perception, as well as staff burnout, psychological well‐being and personality traits.

Results  Regression analyses showed that staff perception of challenging behaviour predicted burnout. Controlling for challenging behaviour, three personality traits (neuroticism, extraversion and conscientiousness) predicted burnout and psychological well‐being.

Conclusions  Personality traits can affect the degree of burnout and poor psychological well‐being that staff may experience. Staff should be informed about the role that their personality traits can play in their well‐being. Training programmes for staff should incorporate the complex relationship between personality traits and well‐being. Further studies should aim at identifying other personality traits that could increase or decrease resilience of staff working in this area.
The DOUBLETIME protein kinase regulates phosphorylation of the Drosophila PDP1ε
Authors: Choi Changtaek , Lee Jongbin , Lim Chunghun , Jang Donghoon , Choe Joonho
Published: August 2009

Reversible phosphorylation of clock proteins plays an important role in circadian timekeeping as it is a key post‐translational mechanism that regulates the activity, stability and subcellular localization of core clock proteins. The kinase DOUBLETIME (DBT), a Drosophila ortholog of mammalian casein kinase Iε, regulates circadian phosphorylation of two essential clock proteins, PERIOD and dCLOCK. We present evidence that Par Domain Protein 1ε (PDP1ε), a transcription factor and mediator of clock output in Drosophila, is phosphorylated in vivo and in cultured cells by DBT activity. We also demonstrate that DBT interacts with PDP1ε and promotes its degradation by the ubiquitin‐proteasome pathway in cultured cells. In addition, PDP1ε nuclear localization is decreased by dbt RNA interference in S2 cell system. These results suggest that DBT regulates phosphorylation, stability and localization of PDP1ε, and that it has multiple targets in the Drosophila circadian system.
THE LEBANESE PHYSICIAN: A PUBLIC'S VIEWPOINT
Authors: ARAWI THALIA
Published: August 2009

A physician's lack of humanity is a general complaint in public surveys. The physician‐patient relationship is viewed by the public as being reduced to a business relationship where the patient feels that she is merely a ‘client’ and the physician a healthcare ‘practitioner’ instead of a ‘care giver’. This public perception is not a phenomenon that is peculiar to Lebanon. Yet, the problem has been increasing over the years to the extent that patients feel that physicians are becoming inhumane and business oriented. While this might not characterize all physicians of the 21st century, this might be true of at least some.

Responses were collected from a study that was undertaken based on a questionnaire distributed to a pool of 650 participants from different geographical areas and different social and educational backgrounds in Lebanon. Participants were all older than18 years and mentally competent. None were physicians. The questionnaire was open‐ended and initially piloted among a random sample.

The physician traits most desired by the public were found to be: moral traits (41%), interpersonal traits (36%), scientific traits (19%) and other (4%). The most unwanted traits/behaviours were a lack of interpersonal traits (57%), a lack of moral traits (40%) and a lack of scientific skills (3%).

The physician‐patient relationship was perceived, in general, as being a flawed one. What can be done to remedy the image of the Lebanese physician that has been projected in the minds of the patients and the public at large? Nine major recommendations are presented.
CULTURE AND GENETIC SCREENING IN AFRICA
Authors: JEGEDE AYODELE S.
Published: August 2009

Africa is a continent in transition amidst a revival of cultural practices. Over previous years the continent was robbed of the benefits of medical advances by unfounded cultural practices surrounding its cultural heritage. In a fast moving field like genetic screening, discussions of social and policy aspects frequently need to take place at an early stage to avoid the dilemma encountered by Western medicine. This paper, examines the potential challenges to genetic screening in Africa. It discusses how cultural practices may affect genetic screening. It views genomics science as a culture which is trying to diffuse into another one. It argues that understanding the existing culture will help the diffusion process. The paper emphasizes the importance of genetic screening for Africa, by assessing the current level of burden of diseases in the continent and shows its role in reducing disease prevalence. The paper identifies and discusses the cultural challenges that are likely to confront genetic screening on the continent, such as the worldview, rituals and taboos, polygyny, culture of son preference and so on. It also discusses cultural practices that may promote the science such as inheritance practices, spouse selection practices and naming patterns. Factors driving the cultural challenges are identified and discussed, such as socialization process, patriarchy, gender, belief system and so on. Finally, the paper discusses the way forward and highlights the ethical considerations of doing genetic screening on the continent. However, the paper also recognizes that African culture is not monolithic and therefore makes a case for exceptions.
Increased CaVβ1a expression with aging contributes to skeletal muscle weakness
Authors: Taylor Jackson R. , Zheng Zhenlin , Wang Zhong‐Min , Payne Anthony M. , Messi María L. , Delbono Osvaldo
Published: August 2009

Ca2+ release from the sarcoplasmic reticulum (SR) into the cytosol is a crucial part of excitation–contraction (E‐C) coupling. Excitation–contraction uncoupling, a deficit in Ca2+ release from the SR, is thought to be responsible for at least some of the loss in specific force observed in aging skeletal muscle. Excitation–contraction uncoupling may be caused by alterations in expression of the voltage‐dependent calcium channel α1s (CaV1.1) and β1a (CaVβ1a) subunits, both of which are necessary for E‐C coupling to occur. While previous studies have found CaV1.1 expression declines in old rodents, CaVβ1a expression has not been previously examined in aging models. Western blot analysis shows a substantial increase of CaVβ1a expression over the full lifespan of Friend Virus B (FVB) mice. To examine the specific effects of CaVβ1a overexpression, a CaVβ1a‐YFP plasmid was electroporated in vivo into young animals. The resulting increase in expression of CaVβ1a corresponded to decline of CaV1.1 over the same time period. YFP fluorescence, used as a measure of CaVβ1a‐YFP expression in individual fibers, also showed an inverse relationship with charge movement, measured using the whole‐cell patch‐clamp technique. Specific force was significantly reduced in young CaVβ1a‐YFP electroporated muscle fibers compared with sham‐electroporated, age‐matched controls. siRNA interference of CaVβ1a in young muscles reduced charge movement, while charge movement in old was restored to young control levels. These studies imply CaVβ1a serves as both a positive and negative regulator CaV1.1 expression, and that endogenous overexpression of CaVβ1a during old age may play a role in the loss of specific force.
Will Iran Look More Like Turkey, Or Turkey Like Iran?
Authors: GARDELS NATHAN
Published: August 2009

istanbul—The effort to forge new forms of non‐Western modernity in the Muslim world has pushed Iran into sometimes bloody civil strife while Turkey swirls with persistent rumors of military plots against the Islamist‐rooted government. The great historical question is whether, in the years to come, Iran will look more like Turkey, or Turkey like Iran?
The Essence of Islamist Resistance: A Different View of Iran, Hezbollah and Hamas
Authors: CROOKE ALASTAIR
Published: August 2009

The Iranian revolution—the political realization of the “Great Refusal” of Western modernization—was a direct consequence a half century later of the forced secularization of the Ottoman Caliphate by Kemal Ataturk. With the superstructure of the Muslim ummah dismantled and replaced by the Turkish nation state, insurgent religious movements, from the (Sunni) Muslim Brotherhood in Egypt to the Shiite imams of Qum and Najaf, moved into the vacuum to reclaim Islam from the shadow of Western dominance.

Now, history is turning again. Iran has been seized by violent turmoil as it seeks to reconcile democracy and religious rule. Secular Turkey is governed by an Islamist‐rooted party. As they struggle to regain their balance, the global economic meltdown threatens a convergence against globalization that joins the Islamist resistance with populist backlashes elsewhere.

Two legendary intelligence agents, a Hezbollah leader, an Iranian dissident philosopher and Shirin Ebadi, the Iranian human rights lawyer and Nobel Laureate, examine this historical turn.
Hezbollah: Islamist Resistance Comes of Age
Authors: QASSEM SHEIKH NAIM
Published: August 2009

The Iranian revolution—the political realization of the “Great Refusal” of Western modernization—was a direct consequence a half century later of the forced secularization of the Ottoman Caliphate by Kemal Ataturk. With the superstructure of the Muslim ummah dismantled and replaced by the Turkish nation state, insurgent religious movements, from the (Sunni) Muslim Brotherhood in Egypt to the Shiite imams of Qum and Najaf, moved into the vacuum to reclaim Islam from the shadow of Western dominance.

Now, history is turning again. Iran has been seized by violent turmoil as it seeks to reconcile democracy and religious rule. Secular Turkey is governed by an Islamist‐rooted party. As they struggle to regain their balance, the global economic meltdown threatens a convergence against globalization that joins the Islamist resistance with populist backlashes elsewhere.

Two legendary intelligence agents, a Hezbollah leader, an Iranian dissident philosopher and Shirin Ebadi, the Iranian human rights lawyer and Nobel Laureate, examine this historical turn.
Iran's Crisis of Legitimacy
Authors: JAHANBEGLOO RAMIN
Published: August 2009

The Iranian revolution—the political realization of the “Great Refusal” of Western modernization—was a direct consequence a half century later of the forced secularization of the Ottoman Caliphate by Kemal Ataturk. With the superstructure of the Muslim ummah dismantled and replaced by the Turkish nation state, insurgent religious movements, from the (Sunni) Muslim Brotherhood in Egypt to the Shiite imams of Qum and Najaf, moved into the vacuum to reclaim Islam from the shadow of Western dominance.

Now, history is turning again. Iran has been seized by violent turmoil as it seeks to reconcile democracy and religious rule. Secular Turkey is governed by an Islamist‐rooted party. As they struggle to regain their balance, the global economic meltdown threatens a convergence against globalization that joins the Islamist resistance with populist backlashes elsewhere.

Two legendary intelligence agents, a Hezbollah leader, an Iranian dissident philosopher and Shirin Ebadi, the Iranian human rights lawyer and Nobel Laureate, examine this historical turn.
A Global Convergence Against Globalization?
Authors: FULLER GRAHAM E.
Published: August 2009

The Iranian revolution—the political realization of the “Great Refusal” of Western modernization—was a direct consequence a half century later of the forced secularization of the Ottoman Caliphate by Kemal Ataturk. With the superstructure of the Muslim ummah dismantled and replaced by the Turkish nation state, insurgent religious movements, from the (Sunni) Muslim Brotherhood in Egypt to the Shiite imams of Qum and Najaf, moved into the vacuum to reclaim Islam from the shadow of Western dominance.

Now, history is turning again. Iran has been seized by violent turmoil as it seeks to reconcile democracy and religious rule. Secular Turkey is governed by an Islamist‐rooted party. As they struggle to regain their balance, the global economic meltdown threatens a convergence against globalization that joins the Islamist resistance with populist backlashes elsewhere.

Two legendary intelligence agents, a Hezbollah leader, an Iranian dissident philosopher and Shirin Ebadi, the Iranian human rights lawyer and Nobel Laureate, examine this historical turn.
Obama Should Be a Second Carter in the Middle East
Authors: VAN CREVELD MARTIN
Published: August 2009

President Barack Obama has extended the hand of engagement to the Muslim and Arab world, while warning Israel against new settlements in occupied Palestine and hedging his bets with remote drone strikes against Al‐Qaida and the Taliban in Pakistan. The new CIA director, a military historian and the Somali‐born feminist Ayaan Hirsi Ali assess his strategy.
Descent of the Dollar and Rise of the Rest
Authors: STIGLITZ JOSEPH
Published: August 2009

Though another Great Depression seems to have been averted for the moment, great geo‐economic shifts are in the works as a result of the global meltdown emanating from Wall Street. Four Nobel laureates in economics take a look at where we are headed.
In‐vitro Comparison of Bag‐Valve‐Mask and the Manually Triggered Oxygen‐powered Breathing Device
Authors: Menegazzi James J. , Winslow Holly J.
Published: August 2009

ABSTRACT

Objective: To determine whether tidal volume, intrapleural pressure, and gastric volume differ when the bag‐valve‐mask (BVM) and the manually triggered oxygen powered breathing device (MTBD) are used in the settings of normal and decreased lung compliance.

Methods: Prospective, randomized in‐vitro model, with emergency medical technician‐paramedics (EMT‐Ps;n= 10) and emergency medical technicians (EMTs; n= 20) blinded to model gauges. Each participant randomly performed four one‐minute trials ventilating a mechanical test lung through an intubation mannikin head at a rate of 20 breaths/min. Each subject used the BVM and the MTBD to ventilate the lung for 20 breaths during normal (0.10 L/cm H2O) and decreased (0.04 L/cm H2O) compliance. Tidal volumes and intrapleural pressures were recorded for every breath and the gastric volume was recorded for each trial using a flowmeter placed below a simulated esophageal sphincter (20 cm H2O PEEP valve).

Results: With normal compliance, mean tidal volumes and intrapleural pressures were not significantly different, while mean gastric volumes differed significantly (BVM = 1,300 mL, MTBD = 0 mL; p < 0.001). When compliance was decreased, mean tidal volumes and intrapleural pressures again did not differ significantly, while gastric volumes remained significantly different (BVM = 3,700 mL, MTBD = 1,100 mL; p < 0.001).

Conclusions: In this model, tidal volumes and intrapleural pressures were similar for the two devices. When compliance was normal, no participant insufflated the stomach with the MTBD, while the gastric volume with BVM ventilation averaged 1.3 L. With decreased compliance, the MTBD again delivered significantly less gastric volume than the BVM (1.1 vs. 3.7 L, respectively). These findings favoring MTBD ventilation require corroboration in vivo.
Intoxicated Airline Pilots: A Case‐based Ethics Model
Authors: Schmidt Terri A.
Published: August 2009

ABSTRACT

The ethical dilemma of managing two intoxicated airline pilots who insist on flying a commercial plane after leaving the emergency department is presented. The case explores the issues surrounding duty to warn, decision‐making capacity, breaching confidentiality, and the requirements of law. A useful ethical decision‐making model is reviewed to address the responsibility of the emergency physician to intervene and the options available.
Endocytosis and Intracellular Trafficking of Human Natural Killer Cell Receptors
Authors: Masilamani Madhan , Peruzzi Giovanna , Borrego Francisco , Coligan John E.
Published: August 2009

Natural killer (NK) cells play a vital role in the defense against viral infections and tumor development. NK cell function is primarily regulated by the sum of signals from a broad array of activation and inhibitory receptors. Key to generating the input level of either activating or inhibitory signals is the maintenance of receptor expression levels on the cell surface. Although the mechanisms of endocytosis and trafficking for some cell surface receptors, such as transferrin receptor and certain immune receptors, are very well known, that is not the situation for receptors expressed by NK cells. Recent studies have uncovered that endocytosis and trafficking routes characteristic for specific activation and inhibitory receptors can regulate the functional responses of NK cells. In this review, we summarize the current knowledge of receptor endocytosis and trafficking, and integrate this with our current understanding of NK cell receptor trafficking.
Serotonin transporter deficiency in rats contributes to impaired object memory
Authors: Olivier J. D. A. , Jans L. A. W. , Blokland A. , Broers N. J. , Homberg J. R. , Ellenbroek B. A. , Cools A. R.
Published: August 2009

Serotonin is well known for its role in affection, but less known for its role in cognition. The serotonin transporter (SERT) has an essential role in serotonergic neurotransmission as it determines the magnitude and duration of the serotonin signal in the synaptic cleft. There is evidence to suggest that homozygous SERT knockout rats (SERT−/−), as well as humans with the short SERT allele, show stronger cognitive effects than wild‐type control rats (SERT+/+) and humans with the long SERT allele after acute tryptophan depletion. In rats, SERT genotype is known to affect brain serotonin levels, with SERT−/−rats having lower intracellular basal serotonin levels than wild‐type rats in several brain areas. In the present study, it was investigated whether SERT genotype affects memory performance in an object recognition task with different inter‐trial intervals. SERT−/−, heterozygous SERT knockout (SERT+/−) and SERT+/+rats were tested in an object recognition test applying an inter‐trial interval of 2, 4 and 8 h. SERT−/−and SERT+/−rats showed impaired object memory with an 8 h inter‐trial interval, whereas SERT+/+rats showed intact object memory with this inter‐trial interval. Although brain serotonin levels cannot fully explain the SERT genotype effect on object memory in rats, these results do indicate that serotonin is an important player in object memory in rats, and that lower intracellular serotonin levels lead to enhanced memory loss. Given its resemblance with the human SERT‐linked polymorphic region and propensity to develop depression‐like symptoms, our findings may contribute to further understanding of mechanisms underlying cognitive deficits in depression.
Molecular Characterization of a Dehydroascorbate Reductase from Pinus bungeana
Authors: Yang Hai‐Ling , Zhao Ying‐Ru , Wang Cai‐Ling , Yang Zhi‐Ling , Zeng Qing‐Yin , Lu Hai
Published: August 2009

Dehydroascorbate reductase (DHAR) plays a critical role in the ascorbate‐glutathione recycling reaction for most higher plants. To date, studies on DHAR in higher plants have focused largely on Arabidopsis and agricultural plants, and there is virtually no information on the molecular characteristics of DHAR in gymnosperms. The present study reports the cloning and characteristics of a DHAR (PbDHAR) from a pine, Pinus bungeana Zucc. ex Endl. The PbDHAR gene encodes a protein of 215 amino acid residues with a calculated molecular mass of 24.26 kDa. The predicted 3‐D structure of PbDHAR showed a typical glutathione S‐transferase fold. Reverse transcription‐polymerase chain reaction revealed that the PbDHAR was a constitutive expression gene in P. bungeana. The expression level of PbDHAR mRNA in P. bungeana seedlings did not show significant change under high temperature stress. The recombinant PbDHAR was overexpressed in Escherichia coli following purification with affinity chromatography. The recombinant PbDHAR exhibited enzymatic activity (19.84 μmol/min per mg) and high affinity (a Km of 0.08 mM) towards the substrates dehydroascorbate (DHA). Moreover, the recombinant PbDHAR was a thermostable enzyme, and retained 77% of its initial activity at 55 °C. The present study is the first to provide a detailed molecular characterization of the DHAR in P. bungeana.
Understanding Remigration and Innovation – An Appeal for a Cultural Economic Geography
Authors: Klaerding Claudia
Published: August 2009

The acquisition of new knowledge is a crucial capital of highly skilled remigrants and its utilisation in home countries can play a major role for regional economic development. By reviewing the remigration literature it is shown that remigrants are able to create innovation in their home countries and promote regional development. But also theoretical deficits can be identified regarding the structural conditions of transferring new knowledge across regions which precedes potential innovation processes. Recent theoretical ideas cannot sufficiently explain why remigrants become innovative to varying degrees depending on their home regions. A cultural approach of economic geography is needed to highlight the cultural construction of the economy. It allows for remigrants to be perceived as knowledge brokers, which crucially influences the returnee’s capacity to innovate.
Broad‐Scale Monitoring of Live Fuel Moisture
Authors: Yool Stephen
Published: August 2009

Remote sensing has as a spaceborne informant about Earth system processes become the technology of choice for monitoring the status of fuels and fire at local through global scales. This study reviews techniques and presents an application of remote sensing for monitoring live fuel moistures at broad spatial scales. The text recalls the roots of biophysical remote sensing, reviewing how early work about the spectral behavior of vegetation offered insights that promoted remote sensing as a fire knowledge source. Time‐series data from the National Oceanic and Atmospheric Administration and Advanced Very High Resolution Radiometer (AVHRR) are used to map relative live fuel moisture stress for the continental USA. Results of fuel moisture maps produced from the AVHRR protocols compare favorably with those derived from the Landsat 7 Enhanced Thematic Mapper Plus.
Measurement of the UVR Exposures of Expeditioners on Antarctic Resupply Voyages†
Authors: Gies Peter , Watzl Roland , Javorniczky John , Roy Colin , Henderson Stuart , Ayton Jeff , Kingston Melissa
Published: August 2009

A study to assess the potential exposure to solar UV radiation of expeditioners on Australian Antarctic resupply voyages was carried out over the Austral summers of 2004/2005 to 2006/2007. Subjects wore UVR‐sensitive polysulphone (PS) badges on the chest for the duration of their working day, which generally ranged from 5 to 10 h, but could be as long as 14 h. Measurements were carried out during unloading of two vessels while they were at the three Australian Antarctic stations. The subjects wore standard Australian Antarctic Division clothing assemblages, although the face and hands and in some cases more of the limbs were uncovered and subjected to exposure to UVR. The badges worn by the subjects received exposures ranging from 0.2 to 18 standard erythemal doses (SEDs), with a median of 3.2 SEDs. However, comparison with occupational exposure limits showed that more than 80% of the subjects’ PS badges received UVR exposures in excess of the limits while 31% received more than five times the limits. Despite sun protection being provided more than 70% of the workers reported mild erythema.
Early Events in Photodynamic Therapy: Chemical and Physical Changes in a POPC:Cholesterol Bilayer due to Hematoporphyrin IX‐mediated Photosensitization
Authors: Santos António , Rodrigues António M. , Sobral Abílio J. F. N. , Monsanto Paula V. , Vaz Winchil L. C. , Moreno Maria João
Published: August 2009

We studied the interaction of hematoporphyrin IX (HpIX) with bilayers of 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine (POPC) containing cholesterol at a molar fraction between 0 and 0.5. The membrane‐associated fraction of HpIX decreases significantly over a period of hours, for porphyrin concentrations in the aqueous phase above 50 nm. This was attributed to self‐aggregation of HpIX and was well described by a dimerization process. A model was developed to correct for aggregation and obtain the true partition coefficient which is dependent on the molar fraction of cholesterol with a maximum at 20 mol%. The chemical and physical effects on the lipid bilayer upon irradiation of HpIX were studied for lipid bilayers with POPC:Chol 1:1. Exposure of these bilayers to visible light in the presence of HpIX leads to several cholesterol oxidation products that were identified using GC‐MS. A dramatic increase in the membrane leakiness was also observed, even for short irradiation times and small light intensities, as evaluated from the rate of pH equilibration and dithionite permeability. The relevance of these results for the mechanism of photodynamic therapy is discussed.
Enantioselective kinetic resolution of phenylalkyl carboxylic acids using metagenome‐derived esterases
Authors: Fernández‐Álvaro Elena , Kourist Robert , Winter Julia , Böttcher Dominique , Liebeton Klaus , Naumer Christian , Eck Jürgen , Leggewie Christian , Jaeger Karl‐Erich , Streit Wolfgang , Bornscheuer Uwe T.
Published: August 2009

Enantiomerically pure β‐arylalkyl carboxylic acids are important synthetic intermediates for the preparation of a wide range of compounds with biological and pharmacological activities. A library of 83 enzymes isolated from the metagenome was searched for activity in the hydrolysis of ethyl esters of three racemic phenylalkyl carboxylic acids by a microtiter plate‐based screening using a pH‐indicator assay. Out of these, 20 enzymes were found to be active and were subjected to analytical scale biocatalysis in order to determine their enantioselectivity. The most enantioselective and also enantiocomplementary biocatalysts were then used for preparative scale reactions. Thus, both enantiomers of each of the three phenylalkyl carboxylic acids studied could be obtained in excellent optical purity and high yields.
Size and Shape of Right Heart Chambers in Mitral Valve Regurgitation in Small‐Breed Dogs
Authors: Carlsson C. , Häggström J. , Eriksson A. , Järvinen A.‐K. , Kvart C. , Lord P.
Published: August 2009

Background:The contribution of right heart (RH) chamber enlargement to general heart enlargement seen on thoracic radiographs in mitral regurgitation (MR) is not known.

Objectives:To determine the size and shape of the RH chambers in normal dogs and dogs with varying degrees of MR.

Animals:Fifty‐four privately owned dogs: 13 normal, 41 with varying degrees of MR including 25 with congestive heart failure (CHF).

Methods:Archived first pass radionuclide angiocardiograms were used to produce static images of the RH and left heart (LH) chambers. Indexes of size and shape of the RH and LH chambers were related to severity of MR determined by heart rate‐normalized pulmonary transit time (nPTT), vertebral heart scale (VHS), and clinical status. RH shape was measured by a circularity index of RH short axis/long axis.

Results:A 2nd degree polynomial fit best described the ratios; RH/LH dimension to nPTT (R2= 0.62) and to VHS (R2= 0.43), RH/LH area to nPTT (R2= 0.64) and to VHS (R2= 0.58), allP< .001. RH circularity was decreased in CHF,P< .001. In CHF, the RH chambers of 16 dogs were both flattened and enlarged, whereas 9 had convex septal borders.

Conclusions:RH chambers are not significantly dilated in dogs with mild to moderate MR without CHF. In CHF, RH chambers enlarge and also may be compressed by the LH chambers. Pulmonary hypertension probably is present in some dogs with CHF. Increased sternal contact is not a useful sign of right‐sided heart dilatation in MR.
How Good Is Open-Cell Metal Foam as Heat Transfer Surface?
Authors: Ghosh Indranil
Published: August 2009

High porosity open-cell metal foam is considered to be an attractive choice for compact heat exchanger applications because of its high area density and superior thermal performance. A systematic study has been made in the present article to verify the suitability of the porous material as an extended heat transfer surface. The area goodness (j/f) factor has been chosen as performance evaluation criterion. This governing parameter has been computed using the existing correlations for the heat transfer and pressure drop coefficients. Conservative estimate shows that the thermohydraulic characteristics of high porosity open-cell metal foam are almost alike, if not better than those of the conventional heat transfer surfaces. Importantly, the analysis has been found to be consistent with the Reynolds analogy. This study helps the designer in making the initial selection of foam surfaces for the heat exchanger application.
Analysis of the Wicking and Thin-Film Evaporation Characteristics of Microstructures
Authors: Ranjan Ram , Murthy Jayathi Y. , Garimella Suresh V.
Published: August 2009

The topology and geometry of microstructures play a crucial role in determining their heat transfer performance in passive cooling devices such as heat pipes. It is therefore important to characterize microstructures based on their wicking performance, the thermal conduction resistance of the liquid filling the microstructure, and the thin-film characteristics of the liquid meniscus. In the present study, the free-surface shapes of the static liquid meniscus in common microstructures are modeled using SURFACE EVOLVER for zero Bond number. Four well-defined topologies, viz., surfaces with parallel rectangular ribs, horizontal parallel cylinders, vertically aligned cylinders, and spheres (the latter two in both square and hexagonal packing arrangements), are considered. Nondimensional capillary pressure, average distance of the liquid free-surface from solid walls (a measure of the conduction resistance of the liquid), total exposed area, and thin-film area are computed. These performance parameters are presented as functions of the nondimensional geometrical parameters characterizing the microstructures, the volume of the liquid filling the structure, and the contact angle between the liquid and solid. Based on these performance parameters, hexagonally-packed spheres on a surface are identified to be the most efficient microstructure geometry for wicking and thin-film evaporation. The solid-liquid contact angle and the nondimensional liquid volume that yield the best performance are also identified. The optimum liquid level in the wick pore that yields the highest capillary pressure and heat transfer is obtained by analyzing the variation in capillary pressure and heat transfer with liquid level and using an effective thermal resistance model for the wick.
Thermodynamically Constrained Averaging Theory Approach for Heat Transport in Single-Fluid-Phase Porous Medium Systems
Authors: Gray William G. , Miller Cass T.
Published: August 2009

The recently developed thermodynamically constrained averaging theory is briefly summarized as a tool for the building of rigorous macroscale models of transport phenomena in complex systems. The specific case of thermal transport in a single-fluid-phase porous medium system is considered. Key results from the application of this theory are used to develop a simplified entropy inequality, which is in turn used to guide the development of closure relations. The decomposition of exchange terms is considered, and closed models for internal energy are derived for the case of nonequilibrium and local thermal equilibrium conditions. Since all variables are expressed in terms of precisely defined averages of microscale quantities, the resultant models can be compared with highly resolved microscale simulations to determine the range of validity of the upscaled models.
A Depletion Strategy for an Active Bottom-Water Drive Reservoir Using Analytical and Numerical Models—Field Case Study
Authors: Nashawi Ibrahim Sami , Al-Anzi Ealian H. , Hashem Yousef S.
Published: August 2009

Water coning is one of the most serious problems encountered in active bottom-water drive reservoir. It increases the cost of production operations, reduces the efficiency of the depletion mechanism, and decreases the overall oil recovery. Therefore, preventive measures to curtail water coning damaging effects should be well delineated at the early stages of reservoir depletion. Production rate, mobility ratio, well completion design, and reservoir anisotropy are few of the major parameters influencing and promoting water coning. The objective of this paper is to develop a depletion strategy for an active bottom-water drive reservoir that would improve oil recovery, reduce water production due to coning, delay water breakthrough time, and pre-identify wells that are candidates to excessive water production. The proposed depletion strategy does not only take into consideration the reservoir conditions, but also the currently available surface production facilities and future development plan. Analytical methods are first used to obtain preliminary estimates of critical production rate and water breakthrough time, then comprehensive numerical investigation of the relevant parameters affecting water coning behavior is conducted using a single well 3D radial reservoir simulation model.
Dual-Permeability Modeling of Capillary Diversion and Drift Shadow Effects in Unsaturated Fractured Rock
Authors: Ho Clifford K. , Arnold Bill W. , Altman Susan J.
Published: August 2009

The drift-shadow effect describes capillary diversion of water flow around a drift or cavity in porous or fractured rock, resulting in lower water flux directly beneath the cavity. This paper presents computational simulations of drift-shadow experiments using dual-permeability models, similar to the models used for performance assessment analyses of flow and seepage in unsaturated fractured tuff at Yucca Mountain. Comparisons were made between the simulations and experimental data from small-scale drift-shadow tests. Results showed that the dual-permeability models captured the salient trends and behavior observed in the experiments, but constitutive relations (e.g., fracture capillary-pressure curves) can significantly affect the simulated results. Lower water flux beneath the drift was observed in both the simulations and tests, and fingerlike flow patterns were seen to exist with lower simulated capillary pressures. The dual-permeability models used in this analysis were capable of simulating these processes. However, features such as irregularities along the top of the drift (e.g., from roof collapse) and heterogeneities in the fracture network may reduce the impact of capillary diversion and drift shadow. An evaluation of different meshes showed that at the grid refinement used, a comparison between orthogonal and unstructured meshes did not result in large differences.
Heat Transfer and Surface Friction Downstream of a Dual Array of Dimples of a Different Shape
Authors: Khalatov Artem , Onishchenko Vitaliy
Published: August 2009

The wide experimental program was carried out in the Institute for Engineering Thermophysics (Kiev, Ukraine) to study heat transfer and surface friction downstream of the dual array of dimples. The test section is the rectangular channel 34 mm height, 290 mm wide and 125 mm long. The unheated dual array of dimples was placed on the channel floor (bottom) wall upstream of the electrically heated test section. Inserts with dimples of spherical, cylindrical and square shape were tested at their relative depth h/D of 0.20 and 0.30. Projected (surface) diameter of dimples is 25.0 mm; the second row was placed in the staggered fashion with the downstream pitch Sx/D of 0.64. The span-wise spacing Sz/D is of 2.0 providing the second row exactly fills in the open span-wise gap between dimples in the first row. The inlet air speed was from 4.1 to 16.6 m/c, Reynolds number Re2H, based on the equivalent (hydraulic) channel diameter varied from 17,400 to 71,800, the inlet boundary layer thickness did not exceed 1.0 mm. According to shape factor measurements the turbulent flow existed in front of dimples for all flow conditions tested. Heat transfer measurements were performed over the center line downstream of the representative dimple placed in the first or second row. The Reynolds number Rex based on the downstream distance was ranged from 3,000 to 105,000. Based on measurements, the conclusion was made that immediately after dimple array (at Rex>3,000) heat transfer corresponds to the turbulent flow data for a smooth flat plate extended into the low Reynolds number area. The downstream heat transfer ratio Nux/Nu0 weakly depends on the dimple shape and depth. The downstream surface friction τw was measured over the central line beyond the dimple placed in the first or second row. The tube-in-flow technique was employed in these measurements. At low probe distances (x/D = 1.2–2.4) the surface friction coefficients locate between classic correlations for the laminar and turbulent flow (extended into the low Reynolds number area) for a smooth flat plate. At high probe distances (x/D > 4.16) the surface friction data agrees well with the classic turbulent flow correlation for the smooth flat plate. Close to the dimple downstream edge (x/D < 2.4) the Reynolds analogy factor is over the unity for all dimple depths and geometries, thus confirming the greater heat transfer increases compared with pressure drop growth. At higher distances, the Reynolds analogy factor is above or below the Reynolds analogy line (RAF = 1.0) depending on the dimple shape and depth. Comparisons on the Reynolds analogy factor magnitude were made in terms of the downstream distances from the dimple back edge.
Density Wave Oscillation in a Vertical Type Natural Circulation Heat Recovery Steam Generator: A Numerical Study
Authors: Walter Heimo , Linzer Wladimir
Published: August 2009

The dynamic flow instability, namely density wave oscillation (DWO), was investigated theoretically. The analysis was done for different design configurations of the evaporator of a vertical type natural circulation heat recovery steam generator (HRSG) at low operation pressure under hot start-up conditions. The study was done for co-current and counter flow designs of the HRSG evaporator, different drum heights and different heat flux distributions over the heating surface of the evaporator. The investigations for the HRSG show that the heat flux distribution to the evaporator tubes has an important influence on the flow stability. The simulation results indicate that a lower amplitude of the mass flow oscillation of the working medium is given by a more uniform heat flux to the single tubes of the evaporator. This leads the two-phase flow system to a more stable condition. This study has also shown that changes in the drum height of the boiler have no significant influence on the oscillation amplitude of the DWO. The simulation results have shown that the counter flow design is much more stable under the investigated conditions compared to the co-current design.
From Research to Didactics: The Course of Dynamics and Control of Fluid Machines for Automation Engineering Students
Authors: Venturini M. , Morini M.
Published: August 2009

The paper deals with the course “Dynamics and Control of Fluid Machines”, which has been held at the Faculty of Engineering of the University of Ferrara (Italy) since the academic year 2002/2003 for the Second-Level Degree Course in Computer Sciences and Automation Engineering. The aim of the course is the study of fluid machines, by combining base knowledge with physical-mathematical analysis of the unsteady behavior and of off-design operating conditions. The first characteristic aspect of the course is the study of the dynamic behavior of fluid machines. The second relevant aspect is the analysis of system control. In this paper, course characteristics are presented and discussed. In particular, as a part of the final examination, students are asked to develop an individual project, whose results are also reported in this paper. The project consists of the simulation of the dynamic behavior of an industrial system for compressed air production by means of a multistage centrifugal compressor. Students are required to properly design the controller and to discuss the adopted control logic. Student feedback is evaluated by means of a survey conducted to evaluate the quality of the didactic activity. The analysis of student feedback reveals that student evaluation towards the course proves higher than the “average” evaluation for the didactic activity held at the University of Ferrara, at the Faculty of Engineering or within the same Degree Course.
Economic Benefits of Hybrid Drive Propulsion for DDG-51 Class Ships
Authors: Willett Fred T. , Reed Greg , Castles Gene
Published: August 2009

The typical operating profile for destroyers and other marine vessels includes a large portion of low-speed activity. Low-speed operation is accompanied by propulsion system inefficiency, as the propulsion turbines are operating off-design. Low speeds are further enabled by propeller pitch variation, which exacerbates system inefficiency. A hybrid propulsion system scheme is proposed that will allow propulsion by either mechanical or electrical drive. Electrical power generated by the ship service turbine-generators (SSTGs) is used to drive large permanent magnet motors. The motors then drive the propeller shafts during low speed operation. This scheme allows the propulsion turbines to be shut down and the ship service turbine-generators to run closer to design point, resulting in fuel savings. Additional savings are possible at higher speeds by operating the motor(s) in generation mode, enabling SSTG shut down and propulsion turbine performance optimization. This paper describes in detail the concept of hybrid drive operation and demonstrates the economic justification for such a system.