bluuebunny/crossref_metadata_2025 huggingface dataset:
Alteration of Heart Rate Variability Parameters in Nondiabetic Hemodialysis Patients
Authors: Tong Yan-Qing , Hou Huo-Ming
Published: January 2007

Objective: We attempt to identify heart rate variability (HRV) components and decide whether or not such components are more sensitive to the hemodialysis (HD) process by excluding the presence of comorbid conditions known to affect HRV. Methods: It was a prospective cohort study of factors associated with HRV. Thirty-five HD patients were admitted to the study. The research was divided into three phases. During the first phase, baseline Holter and blood pressure recordings were carried out. Then in the second phase, the patients were admitted for HD with continuous Holter and blood pressure recording. The third phase was after HD with continuous Holter and blood pressure recording. The frequency and time domain analyses of HRV were carried out by an independent, blinded investigator. Plasma Na+, K+, ionized Ca, hemoglobin, serum creatinine and blood urea nitrogen (BUN) were checked 1 h before and 2 h after HD. Results: After HD, the serum creatinine and BUN were obviously reduced (p < 0.01), which was also expressed by fractional urea clearance (Kt/V; 1.55 ± 0.25), which means efficient HD. Standard deviation of all RR intervals and low-frequency/high-frequency (LF/HF) ratio were reduced significantly (p < 0.05) at the ‘HD for 3 h’ time point while the blood pressure levels were relatively stable during the HD process. The ultrafiltration rate and Kt/V appeared to be the main determinants of the LF/HF ratio in HD. In our cases, the LF/HF ratio positively correlated with Kt/V and negatively correlated with ultrafiltration volume. Conclusion: Our study suggested a shift in sympathovagal balance toward sympathetic activation during the HD process. Sympathetic overactivity is positively correlated with the ultrafiltration rate, and negatively correlated with the Kt/V which means that the HD process itself affects HRV parameters indeed.
Remote Sensing of Water Cloud Parameters Using Neural Networks
Authors: Cerdeña Abidán , González Albano , Pérez Juan C.
Published: January 2007

In this work a method for determining the micro- and macrophysical properties of oceanic stratocumulus clouds is presented. It is based on the inversion of a radiative transfer model that computes the albedos and brightness temperatures in the NOAA Advanced Very High Resolution Radiometer (AVHRR) channels. This inversion is performed using artificial neural networks (ANNs), which are trained and optimized by genetic algorithms to fit theoretical computations. A detailed study of the ANN parameters and training algorithms demonstrates the convenience of using the “backpropagation with momentum” method. The proposed retrieval method is applied to daytime and nighttime imagery and was validated using ground data collected in Tenerife (Canary Islands), obtaining a good agreement.
Wideband Reception and Processing for Dual-Polarization Radars with Dual Transmitters
Authors: Choudhury Sutanay , Chandrasekar V.
Published: January 2007

Oversampling pulsed Doppler radar returns at a rate larger than the pulse bandwidth, whitening the range samples, and subsequent averaging has been pursued as a potential way to decrease the measured standard deviation of signal parameter estimates. It has been shown that the application of oversampling, whitening, and subsequent averaging improves the quality of reflectivity, mean velocity, and spectral width estimates in agreement with theory. Application of this procedure to a dual-polarization radar with dual transmitters is evaluated in this paper. Oversampled data collected from the Colorado State University (CSU)-University of Chicago–Illinois State Water Survey (CHILL) radar using a wideband receiver are analyzed to evaluate the performance of dual-polarization parameter estimators, such as differential reflectivity and differential phase. The negative impact of relative phase characteristics of the transmitted pulses in two polarizations on the copolar correlation, and subsequently on polarimetric parameter estimation, is analyzed. CSU-CHILL radar’s transmitted pulse sampling capability is used to evaluate the impact of the transmitted waveform’s mismatch on whitening and estimation.
Global Brand Expansion
Authors: Dev Chekitan S. , Brown James R. , Zhou Kevin Zheng
Published: January 2007

When hotel firms expand internationally, they must determine the ownership strategy and the management strategy that will best maintain the firm’s competitive advantage. Those decisions are made separately from each other and depend on the expanding company’s own strengths and the strengths found in the local market. That interplay between the company’s strengths and local resources drives the type of partnership or affiliation arrangement that the company uses to enter the foreign market. The decision regarding who controls management and marketing, for instance, depends to a large extent on whether the expanding company can rely on local interests to maintain the firm’s customer service standards. If the firm does not use customer service as a competitive advantage, it can make more use of third-party interests to operate the hotel. If the hotel facility is itself a point of competitive advantage, the decision on the extent of equity investment by the firm rests on whether local interests have sufficient resources to build and maintain the property.
Understanding Customer-Derived Value in the Timeshare Industry
Authors: Sparks Beverley , Butcher Ken , Pan Grace
Published: January 2007

The timeshare sector has grown substantially over the past decade in both size and product configuration. Focusing on the concept of customer-derived value, group interviews were conducted with owners of timeshare holiday products to assess the dimensions of customer value in timeshares. Twelve such dimensions of value emerged from the interviews, most notably knowledge enhancement. Six detractors of derived value were identified. With a better understanding of the sources of value for timeshare owners, managers can recruit new owners, develop products, and enhance the levels of satisfaction and loyalty among existing owners.
The Combined Effects of the Physical Environment and Employee Behavior on Customer Perception of Restaurant Service Quality
Authors: Wall Eileen A. , Berry Leonard L.
Published: January 2007

Dining in a table-service restaurant is a multilayered experience that involves at least three types of clues. Although food quality is basic, the ambience and service performance greatly influence a customer’s evaluation of a particular establishment. Diners use the following types of clues to judge a restaurant experience: functional—the technical quality of the food and service; mechanic—the ambience and other design and technical elements; and humanic—the performance, behavior, and appearance of the employees. While customers’ perceptions of mechanic clues are positively related to their expectations of the service, humanic clues dominate the influence of mechanic clues. Ideally, managers should orchestrate both humanic and mechanic clues to deliver a consistent service message.
Employment Discrimination in the Restaurant Industry
Authors: Slonaker William M. , Wendt Ann C. , Baker Bud
Published: January 2007

An analysis of a database compiled by the authors from claims recorded by the Ohio Civil Rights Commission found that three causes of action accounted for most employment-discrimination claims against restaurants in that state. Those causes are (in decreasing order of frequency) race, sex, and retaliation. When the restaurants are analyzed according to type, however, the frequency of claims changes. One particular change of note is the rise of retaliation claims, which overwhelmingly follow complaints based on other causes. This cause of action merits attention from restaurant operators because a retaliation claim can continue even if the original complaint fails or is dropped.
Reasons given by high school students for refusing sexually transmitted disease screening
Authors: Sanders Ladatra S , Nsuami Malanda , Cropley Lorelei D , Taylor Stephanie N
Published: January 2007

Objective To determine reasons given by high school students for refusing to participate in a school-based noninvasive chlamydia and gonorrhea screening that was offered at no cost to students, using the health belief model as theoretical framework.

Design Cross-sectional survey.

Setting Public high schools in a southern urban United States school district.

Methods Every year since the school year 1995–1996, students in the school district have been offered free and confidential chlamydia and gonorrhea screening using nucleic acid amplification tests in urine specimens. All youth in the participating schools are eligible for screening if they have parental consent or are aged 18 years or older and provide consent. In 2004–2005, 50 males and 106 females who had consent but chose not to participate were asked to fill out a self-administered confidential survey about their reasons for refusing participation.

Results The most frequent single reason males gave for refusing to participate in the screening was that they just did not want to take the test ( n = 24); females most frequently refused because they have never had sex ( n = 32) or they just did not want to take the test ( n = 26). Respectively, 22 males (44.0 per cent) and 63 females (59.4 per cent) perceived themselves not being susceptible to chlamydia or gonorrhea, 2 males (4.0 per cent) and 2 females (1.9 per cent) felt chlamydia and gonorrhea were not serious diseases, 11 males (22.0 per cent) and 37 females (34.9 per cent) perceived barriers and 4 males (8.0 per cent) and 1 female (0.9 per cent) saw no benefi t to chlamydia or gonorrhea screening.

Conclusion Respondents most frequently refused to participate because they simply did not want to take the test. Most females refused because they had never had sex. Many perceived themselves as not being susceptible to chlamydia and gonorrhea solely on the basis of misconceptions that are amenable to correction through health education.
Schoolchildren who are victims of bullying report benefit from health dialogues with the school health nurse
Authors: Borup Ina , Holstein Bjørn E
Published: January 2007

Background School health services are important tools for health promotion among schoolchildren, but little is known about their effects. This article addresses the effects of dialogues with school health nurses among schoolchildren who were victims of bullying.

Study population and methods Cross-sectional and school-based survey, the Danish contribution to the international Health Behaviour in School-aged Children (HBSC) study. The study included all students in the fifth, seventh, and ninth grade (11, 13, and 15 year olds) in a random sample of schools. The participation rate was 98 per cent of the students present on the day of data collection and 88 per cent of the enrolled students, n = 5205.

Measurements Bullying was measured as recommended by Olweus. Outcome of the dialogue with the school health nurse was measured as self-reports of five responses: (1) reflected on the dialogue, (2) discussed the content with parents, (3) followed the advice from the school health nurse, (4) did what he (she) himself (herself) thought was best, and (5) visited the school health nurse again.

Results All outcome measures were more prevalent among students who were victims of bullying. The most pronounced association was that the odds ratio for visiting the school health nurse again was 1.8 (95 per cent CI 1.3–2.5) for students who were bullied at least weekly.

Conclusion Schoolchildren who are victims of bullying benefit from health dialogues with the school health nurse.
A study of the gender-specific mortality rates in Korea and Japan for the formation of health promotion policy
Authors: Nam Eun-Woo , Song Yea-Li-A
Published: January 2007

Objective This study attempts to provide fundamental information to help with the development of health policy and health services by looking at the trends of the gender-specific mortality rates in Korea and Japan.

Design The death statistics of Korea and Japan over the 21-year period from 1983 to 2003 are analyzed.

Setting We used the death statistics and estimated population fi gures published by the Korean National Statistical Office, and the vital statistics published by Ministry of Health and Welfare of Japan.

Method Mortality data are standardized ×100,000 to 2001/2003. specific mortality rates from 12 selected causes are considered: tuberculosis, malignant neoplasms, diabetes mellitus, hypertensive diseases, heart diseases, cerebrovascular disease, pneumonia, diseases of the liver, renal failure, transport accidents, falls and suicide.

Results In Korea, the mortality rates from malignant neoplasms, diabetes mellitus, renal failure, falls and suicide have increased. The proportion of the mortality rates from chronic diseases is higher than from acute diseases. In Japan, the mortality rate from pneumonia increased more than that from diabetes mellitus. The gap in mortality rates between males and females in Korea is greater, especially in terms of malignant neoplasms, diseases of the liver, transport accidents and suicide.

Conclusion The mortality rates from these diseases are higher in males than in females. For the recent health promotion policies in Korea such as Health Plan 2010, a more intensive and objective management drawing on the findings of this study concerning gender-specific mortality rates should be implemented.
Work and Family Directions in the USA and Australia: A Policy Research Agenda
Authors: Drago Robert , Pirretti Amy , Scutella Rosanna
Published: January 2007

This article provides a comparative glimpse of work/family issues in Australia and the USA. It begins with a summary of an emerging vision of ideal policies and practices for work and family. The article then provides historical background for the recent emergence of a ‘care gap’ in both countries, focusing on key commonalities and differences. The current status of the gap and the related ‘default solution’ to the gap are then outlined. Key commonalities here include an increasing diversity of family forms, a rise in delayed and denied childbearing, and substantial gender inequality. Significant current divergence across the societies includes relatively more family-responsive governmental policies in Australia, more attractive part-time opportunities for mothers in Australia, a relatively more equal division of labor in the home in the USA, a greater prevalence of corporate-sponsored work/family policies in the USA, and greater coverage of Australian employees by work/family policies negotiated through enterprise agreements. A tentative research agenda is provided in conclusion, focusing on part-time employment options, work incentives and childcare for single parents, the causes of delayed and denied childbearing, and enterprise bargaining and corporate policies.
The Paradox of Tripartitism and Employment Relationships in an Industry of Service-Providing Agencies in Hong Kong
Authors: Sek-Hong Ng , Ip Olivia , Chan Andy W.
Published: January 2007

This article explores the role of industrial ‘tripartitism’ as a feature of industrial relations in Hong Kong. Drawing on data from a survey of the property management industry they conducted, the authors show how diversity in the forms of hiring practices and heterogeneity in the composition of the workforce contribute to an impasse in which an industrial tripartite council is bogged down despite its stated mission. The controversies arise from the issue of the long work hours of the security guards, leading to wide public concern and the subsequent proposed change from the industry norm of the two-shift day to a three-shift day for the workers. The case study also attests to the difficulties in setting up industry-wide work standards due to intra-sectoral diversities, and in particular, the dual labour market conditions and the multi-tiered principal-agent relationship arising from outsourcing arrangement.
Hybrid fuzzy logic control strategies for hot water district heating systems
Authors: Lianzhong L , Zaheeruddin M
Published: January 2007

Hybrid fuzzy logic control (FLC) strategies for hot water district heating (HWDH) systems are designed. A non-linear dynamic model of a HWDH system (heated floor area 90 000 m2) with 21 dynamic equations is developed. The dynamic model consists of a boiler, pipe network, heaters and buildings. Six different hybrid control strategies involving FL and PI control were designed to regulate fuel firing rate, water flow rate or water temperature in the system. Simulation results show that the control strategies, based on the use of return water temperature and indoor air temperature predictor (IATP), give good zone temperature control. Pumping costs were reduced by modulating water flow rate in the system. Results also showed that the proposed hybrid control strategies could save up to 17% energy in buildings.
Determining the adventitious leakage of buildings at low pressure. Part 2: pulse technique
Authors: Cooper E W , Etheridge D W , Smith S J
Published: January 2007

Part 1 of this paper examined the uncertainties (errors) inherent in the determination of the low-pressure leakage of a building envelope. It was shown that a technique for direct measurement of Q4 could reduce the uncertainty by a factor of three or more. In Part 2, a technique is described that enables such measurements to be made. There are three key features that lead to a successful technique. The first is to measure Dp a short time before and after the pulse, thereby allowing wind effects to be largely eliminated. The second is to choose the shape and duration of the pulse, such that a period of quasi-steady flow is obtained. The third is to minimise the variation of Dp during the quasi-steady period, such that envelope flexing is not a problem. Examples of measurements are presented that demonstrate these key features. Further evidence of the suitability of the technique is provided by demonstrating its ability to determine a known change of opening. Comparisons are also made between the new technique, the conventional steady technique, and a theoretical model. It is concluded that the new technique allows the low-pressure leakage of a building to be determined to an accuracy that has not previously been possible.
The Role of Other Orientation in Reactions to Job Characteristics
Authors: Meglino Bruce M. , Korsgaard M. Audrey
Published: January 2007

Attitudes are shaped through a rational process of integrating one’s beliefs and valences and an automatic process involving heuristics. This investigation extends research on the theory of other orientation by examining the role of other orientation in the first of these two processes. In two survey samples and a follow-up laboratory experiment, the relationship between beliefs about enriched job attributes and job satisfaction was weaker among persons higher in other orientation. These findings specify a different role for individual differences in job attitude formation that has implications for influencing job attitudes among persons from different professions, organizations, and cultures.
Correlates of cross-sex friendship satisfaction in Hong Kong adolescents
Authors: Cheung Sum Kwing , McBride-Chang Catherine
Published: January 2007

During adolescence, the number of cross-sex friends increases dramatically. This study focused on correlates of adolescents' cross-sex friendship satisfaction. Three hundred and twenty Hong Kong secondary four (10th grade) students were asked to rate their best cross-sex friends on the Friendship Satisfaction Scale (Tsuzuki & Matsui, 2000). Masculinity, school type, total number of cross-sex friends, and both generic and unique friendship motives significantly explained 48.9% of adolescents' satisfaction with their cross-sex friends. Thus, variables ranging from individual traits to opportunity structures can all be useful in understanding adolescents' cross-sex friendship development.
The contribution of adult personality and recalled parent–child relations to friendships in middle and old age
Authors: Heyl Vera , Schmitt Marina
Published: January 2007

In this study we examined personality traits, in particular openness to experience and agreeableness, and–in an exploratory step – recalled parent–child relations as antecedents of friendship involvement in adulthood. Data from 392 middle-aged (43–46 years) and 345 older participants (61–64 years) in the first wave of the Interdisciplinary Longitudinal Study of Adult Development (ILSE) support the hypothesis that openness contributes to friendship involvement in middle age, while agreeableness contributes to friendship involvement in old age. Further, structural equation models showed that the relation between recalled mother–child relationship and friendship involvement in older adults was mediated by agreeableness. Recalled father–child relationship was directly associated with friendships in both age groups, independent of personality traits.
Third language acquisition: why it is interesting to generative linguists
Authors: Leung Yan-kit Ingrid
Published: January 2007

The present article reviews three collections of papers edited by Cenoz and colleagues on the topic of third language (L3) acquisition from perspectives including psycholinguistics, sociolinguistics and education. Our focus is on psycholinguistics, in particular, lexical acquisition studies, and with particular reference to two central notions in the study of L3, namely, language-selectiveness and cross-linguistic influence. The article also discusses expansion of the study of L3 acquisition into the Universal Grammar/Second Language Acquisition (UG/SLA) paradigm, and closes by looking at future directions for the L3 field.
Comparison of hollow-fiber membrane oxygenators with different perfusion modes during normothermic and hypothermic CPB in a simulated neonatal model
Authors: Ündar Akif , Ji Bingyang , Lukic Branka , Zapanta Conrad M , Kunselman Allen R , Reibson John D , Khalapyan Tigran , Baer Larry , Weiss William J , Rosenberg Gerson , Myers John L
Published: January 2007

Purpose: The objectives of this investigation were (1) to compare two hollow-fiber membrane oxygenators (Capiox Baby RX versus Lilliput 1-D901) in terms of pressure drops and surplus hemodynamic energy (SHE) during normothermic and hypothermic cardiopulmonary bypass (CPB) in a simulated neonatal model; and (2) to evaluate pulsatile and non-pulsatile perfusion modes for each oxygenator in terms of SHE levels.

Methods: In a simulated patient, CPB was initiated at a constant pump flow rate of 500 mL/min. The circuit was primed with fresh bovine blood. After 5 min of normothermic CPB, the pseudo-patient was cooled down to 25°C for 10 min followed by 30 min of hypothermic CPB. The pseudo-patient then underwent 10 min of rewarming and 5 min of normothermic CPB. At each experimental site (pre- and post-oxygenator and pre-aortic cannula), SHE was calculated using the following formula {SHE (ergs/cm3) = 1332 [((ffpdt)/(ffdt))-mean arterial pressure]} (f = pump flow and p = pressure). A linear mixed-effects model that accounts for the correlation among repeated measurements was fit to the data to assess differences in SHE between oxygenators, pumps, and sites. Tukey’s multiple comparison procedure was used to adjust p-values for post-hoc pairwise comparisons.

Results: The pressure drops in the Capiox group compared to the Lilliput group were significantly lower during hypothermic non-pulsatile (21.3∓0.5 versus 50.7∓0.9 mmHg, p B < 0.001) and pulsatile (22∓0.0 versus 53.3∓0.5 mmHg, p < 0.001) perfusion, respectively. Surplus hemodynamic energy levels were significantly higher in the pulsatile group compared to the non-pulsatile group, with Capiox (1655∓92 versus 10 008∓1370 ergs/cm3, p < 0.001) or Lilliput (1506∓112 versus 7531∓483 ergs/cm3, p < 0.001) oxygenators. During normothermic CPB, both oxygenators had patterns similar to those observed under hypothermic conditions.

Conclusions: The Capiox oxygenator had a significantly lower pressure drop in both pulsatile and non-pulsatile perfusion modes. For each oxygenator, the SHE levels were significantly higher in the pulsatile mode.
Arterio-venous gradients of free energy change for assessment of systemic and splanchnic perfusion in cardiac surgery patients
Authors: Braun Jan-Peter , Jakob Stephan M , Volk Thomas , Doepfmer Ulrich R , Moshirzadeh Maryam , Stegmann Shirin , Dohmen Pascal M , Spies Claudia
Published: January 2007

Objective: Adequacy of organ perfusion depends on sufficient oxygen supply in relation to the metabolic needs. The aim of this study was to evaluate the relationship between gradients of free energy change, and the more commonly used parameter for the evaluation of the adequacy of organ perfusion, such as oxygen-extraction in patients undergoing valve replacement surgery using normothermic cardiopulmonary bypass (CPB).

Methods: In 43 cardiac patients, arterial, mixed venous, and hepato-venous blood samples were taken synchronously after induction of anaesthesia (preCPB), during CPB, and 2 and 7 h after admission to the intensive care unit (ICU+2, ICU+7). Blood gas analysis, cardiac output, and hepato-splanchnic blood flow were measured. Free energy change gradients between mixed venous and arterial (-ΔΔG(v-a)) and hepato-venous and arterial (-ΔΔG(hv-a)) compartments were calculated.

Measurements and results: Cardiac index (CI) increased from 1.9 (0.7) to 2.8 (1.3) L/min/m (median, inter-quartile range) (p =0.001), and hepato-splanchnic blood flow index (HBFI) from 0.6 (0.22) to 0.8 (0.53) L/min/m (p =0.001). Despite increasing flow, systemic oxygen extraction increased after CPB from 24 (10)% to 35 (10)% at ICU+2 (p =0.002), and splanchnic oxygen extraction increased during CPB from 37 (19)% to 52 (14)% (p =0.001), and remained high thereafter. After CPB, high splanchnic and systemic gradients of free energy change gradients were associated with high splanchnic and systemic oxygen extraction, respectively (p =0.001, 0.033, respectively).

Conclusion: Gradients of free energy change may be helpful in characterising adequacy of perfusion in cardiac surgery patients independently from measurements or calculations of data from oxygen transport.
Discoid Meniscus
Authors: Atay Ozgur Ahmet , Pekmezci Murat , Doral Mahmut Nedim , Sargon Mustafa Fevzi , Ayvaz Mehmet , Johnson Darren L.
Published: January 2007

Background

The ultrastructure of the normal menisci has been thoroughly investigated and found to correlate with meniscal tears. Although discoid menisci are accepted to have the same composition as their normal counterparts, to our knowledge, no study in the literature has investigated this issue.

Purpose

To investigate the ultrastructure of the discoid menisci and compare it with nondiscoid menisci.

Study Design

Descriptive laboratory study.

Methods

Meniscal biopsies were taken from 12 patients who were operated for meniscus tear and diagnosed with discoid meniscus and from 6 patients who were operated for meniscal tear and did not have a diagnosis of discoid meniscus. The samples were examined with transmission electron microscopy.

Results

The study group demonstrated a decrease in the number of collagen fibers compared with the control group. Also, the homogeneous course of the collagen fibers observed in the control group was replaced by a heterogeneous course in the study group.

Conclusion

The ultrastructure of the discoid meniscus is different from the normal menisci.

Clinical Relevance

This difference may contribute to the vulnerability of the discoid meniscus to tears.
Excessive Apoptosis in Patellar Tendinopathy in Athletes
Authors: Lian Øystein , Scott Alex , Engebretsen Lars , Bahr Roald , Duronio Vincent , Khan Karim
Published: January 2007

Background

The pathogenesis of tendon overuse injuries is poorly understood. The histopathology underlying tendinopathy at various anatomical locations is similar and may reflect a common pathologic process.

Hypothesis

Apoptosis contributes to the pathophysiology in patellar tendinopathy.

Study Design

Case control study; Level of evidence, 3.

Methods

We compared biopsy specimens from the patellar tendon in patients with patellar tendinopathy diagnosed clinically and with typical magnetic resonance image findings with biopsy specimens from a control group without any previous or current knee complaints to suggest patellar tendinopathy. The presence of apoptosis was examined with immunohistochemical methods using a polyclonal antibody recognizing active caspase-3, confirmed by labeling DNA strand breaks (F7-26 antibody) and nuclear morphology (fragmentation and condensation).

Results

The number of apoptotic cells per unit area (4.5 mm2) was 0.91 ± 0.81 (SD) in tendinopathic samples and 0.21 ± 0.21 in controls (P = .026). Although the tendinopathic samples displayed increased cellularity (average 162.5 nuclei/mm 2 vs 98.9 nuclei/mm2), the apoptotic index was higher (0.42% vs 0.17%, P = .014).

Conclusion

Increased apoptotic cell death is a feature of patellar tendinosis. The role of apoptosis within the broader framework and time course of tendon overuse injury remains to be established.
Revolutionary Secrets: Technology’s Role in the South African Anti-Apartheid Movement
Authors: Garrett R. Kelly , Edwards Paul N.
Published: January 2007

In the late 1980s, Operation Vula brought exiled African National Congress (ANC) leaders and military capacity into South Africa despite legal and military obstacles. According to participants, a purpose-built encrypted communication system was critical to this success, but what was the significance of the technology? Was it simply a catalyst for change within the ANC leadership, or did the system crucially alter the political situation? This case study highlights the importance of four key factors affecting the interaction between new information and communication technologies (ICTs) and social movements. The factors are (a) ongoing technological innovation, (b) user practices, (c) technical competence, and (d) organizational routines. Scholarship that fails to consider these factors risks oversimplifying the process of sociotechnical change, hampering our ability to understand the relationship between ICTs and contentious political activity.
Is there a role for PCR-SSCP among the methods for missense mutation detection of TP53 gene?
Authors: Peltonen J , Welsh J A , Vähäkangas K H
Published: January 2007

Mutation analysis methods have increased in variety during the past years. High-throughput microarray methods have especially increased in popularity. However, new methods require reference points, and not all of the methods are equal in sensitivity and specificity. Furthermore, the detection of unknown missense mutations, such as unknown TP53 mutations in human tumors, for clinical purposes requires great accuracy, which may be difficult to acquire with the current high-throughput methods. For these reasons, the classical methods, such as PCR-manual sequencing and PCR-SSCP, are still valuable and necessary.
Acute and repeat-dose toxicity studies of the (6-maleimidocaproyl)hydrazone derivative of doxorubicin (DOXO-EMCH), an albumin-binding prodrug of the anticancer agent doxorubicin
Authors: Kratz F , Ehling G , Kauffmann H-M , Unger C
Published: January 2007

The (6-maleimidocaproyl)hydrazone derivative of doxorubicin (DOXO-EMCH) is an albumin-binding prodrug of doxorubicin with acid-sensitive properties that demonstrates superior antitumor efficacy in murine tumor models, and has been evaluated in a phase I study. In order to establish the toxicity profile of this prodrug, acute and repeat-dose toxicity studies were performed with DOXO-EMCH in CD1-mice, Sprague-Dawley rats and Beagle dogs. Although the objective of the acute toxicity studies was not the determination of LD50 values, the LD50 of DOXO-EMCH was >60mg/kg doxorubicin equivalents in both male and female mice (the LD50 of doxorubicin in CD-1 mice is ~12 mg/kg). In Sprague-Dawley rats, the LD50 was 23.4 and 45.9 mg/kg doxorubicin equivalents for males and females, respectively. For comparison, the LD50 of doxorubicin in Sprague-Dawley rats is ~10.5 mg/kg. The major clinical sign noted following intravenous administration of DOXOEMCH in mice and rats was a dose-dependent peripheral neuropathy which, in general, developed as a delayed toxicity 1-3 weeks after application. The observed neurotoxicity has been well documented for Sprague-Dawley rats treated with doxorubicin at a dose of 5 and 10 mg/kg. In Beagle dogs, LD10 was not reached for DOXO-EMCH at 4.5 mg/kg doxorubicin equivalents. A four-cycle intravenous study with DOXO-EMCH at dose levels of 4×2.5, 5.0 or 7.5 mg/kg doxorubicin equivalents in rats revealed approximately three-fold less side effects on the hemolymphoreticular system when compared to 4×2.5 mg/kg doxorubicin dose, whereas effects on the testes/oligospermia seem to be comparable between both drugs at equitoxic dose. A No Observable Adverse Effect Level (NOAEL) for DOXO-EMCH of 4×2.5 mg/kg doxorubicin equivalents was established in this study. This dose is equivalent to the maximum tolerated dose (MTD) of doxorubicin in rats. In a two-cycle study over a period of 6 weeks in Beagle dogs (intravenous administration of DOXO-EMCH at dose levels of 1.5, 3.0 or 4.5 mg/kg doxorubicin equivalents), dose-related systemic histamine-like reactions within the first 3 hours after injection were noted in all treated groups. Only transient and temporary effects on hematology, urinary function, as well as on histopathology in mid- and/or high-dose animals, were observed. The low dose of 2×1.5 mg/kg was considered to be the NOAEL in this study, which is equivalent to twice the MTD of doxorubicin in Beagle dogs. In summary, the toxicity studies with DOXO-EMCH in mice, rats or dogs have not identified any other special toxicity when compared to the toxicity data for doxorubicin. Preclinical tolerance of DOXO-EMCH was higher in mice, rats and dogs compared to doxorubicin. A dose of 20 mg/m2 doxorubicin equivalents was recommended as the starting dose for a phase I study with DOXO-EMCH.
Mimicking Protein Dynamics by the Integration of Elastic Network Model with Time Series Analysis
Authors: Alakent Burak , Camurdan Mehmet C. , Doruker Pemra
Published: January 2007

Anisotropic network model (ANM) is a coarse-grained normal mode analysis that is widely used for describing the collective motions of proteins around their native structure. In this work, protein dynamics along ANM modes are constructed by linear stochastic time series models extracted from molecular dynamics (MD) simulations, and these models are simulated to mimic the dynamics of a relatively small protein, tendamistat. It is found that ANM modes are at least as successful as principal components analysis in explaining different conformational subspaces, and the nonstationary character of ANM modes is a further advantage. The significant reduction in computation time makes time series simulations a promising alternative to the standard requirement of performing multiple long MD runs especially in water, provided that a single short MD is available for extracting the models and some energy restrictions are performed during the moves.
Motivation in transition
Authors: Stauber Barbara
Published: January 2007

This article explores the subject of motivation in young people’s transitions to work, which has become a crucial issue for youth and educational policies throughout Europe, in response to problems of young people leaving school early or later drop-out and withdrawal. While young people’s disengagement means that educational and career services have difficulty staying in contact with them, findings from a recent research project show, in an exemplary way, how disengaged young people can be re-motivated to develop a proactive attitude towards their transitional biographies. This research identifies various modes of (biographical) participation as a prerequisite for such motivational change.
The Measurement of Radon and Radium Concentrations in Well Water in the Afyonkarahisar area of Turkey
Authors: Yalim H. A. , Akkurt I. , Ozdemir F. B. , Unal R. , Sandikcioglu A. , Akkurt A.
Published: January 2007

Radon, a naturally occurring radioactive noble gas, is the main source of the natural radiation that is received by the population. It derives from the traces of radium in rocks and can diffuse directly or as solution in water to the earth’s surface. Measurements of radium and radon concentration in a total of ten different well waters sampled at about 100m depth in the Afyonkarahisar area of Turkey have been made. It was found that the concentration ranged from 0.42-28.82Bq·L-1 for radon and from 0.07-7.16Bq·L-1 for radium. A 99% correlation between radon and radium concentrations was found. From these data the average annual effective dose equivalent from radon and radium in the water have been estimated to about 73.8 and 778.96μSv·y-1, respectively.
Antithrombin Cambridge II (A384S): an underestimated genetic risk factor for venous thrombosis
Authors: Corral Javier , Hernandez-Espinosa David , Soria Jose Manual , Gonzalez-Conejero Rocio , Ordonez Adriana , Gonzalez-Porras Jose Ramon , Perez-Ceballos Elena , Lecumberri Ramon , Sanchez Ignacio , Roldan Vanessa , Mateo Jose , Minano Antonia , Gonzalez Marcos , Alberca Ignacio , Fontcuberta Jordi , Vicente Vicente
Published: January 2007

The antithrombin A384S mutation has a relatively high frequency in the British population but has not been identified in other populations. This variant has been associated with cases of thrombotic disease, but its clinical relevance in venous thrombosis remained unclear. We have conducted a secondary analysis of the prevalence of the mutation in a large case-control study, including 1018 consecutive Spanish patients with venous thromboembolism. In addition, we evaluated its functional consequences in 20 carriers (4 homozygous). This mutation, even in the homozygous state, did not affect anti-Xa activity or antigen levels, and it only slightly impaired anti-IIa activity. Thus, routine clinical methods cannot detect this anomaly, and, accordingly, this alteration could have been underestimated. We identified this mutation in 0.2% of Spanish controls. Among patients, this variant represented the first cause of antithrombin anomalies. Indeed, 1.7% patients carried the A384S mutation, but 0.6% had any other antithrombin deficiency. The mutated allele was associated with an increased risk of venous thrombosis with an adjusted OR of 9.75 (95% CI, 2.2-42.5). This is the first study supporting that antithrombin A384S mutation is a prevalent genetic risk factor for venous thrombosis and is the most frequent cause of antithrombin deficiency in white populations.
Heterochromatic gene repression of the retinoic acid pathway in acute myeloid leukemia
Authors: Fazi Francesco , Zardo Giuseppe , Gelmetti Vania , Travaglini Lorena , Ciolfi Alberto , Di Croce Luciano , Rosa Alessandro , Bozzoni Irene , Grignani Francesco , Lo-Coco Francesco , Pelicci Pier Giuseppe , Nervi Clara
Published: January 2007

Alteration of lineage-specific transcriptional programs for hematopoiesis causes differentiation block and promotes leukemia development. Here, we show that AML1/ETO, the most common translocation fusion product in acute myeloid leukemia (AML), counteracts the activity of retinoic acid (RA), a transcriptional regulator of myelopoiesis. AML1/ETO participates in a protein complex with the RA receptor alpha (RARα) at RA regulatory regions on RARβ2, which is a key RA target gene mediating RA activity/resistance in cells. At these sites, AML1/ETO recruits histone deacetylase, DNA methyltransferase, and DNA-methyl-CpG binding activities that promote a repressed chromatin conformation. The link among AML1/ETO, heterochromatic RARβ2 repression, RA resistance, and myeloid differentiation block is indicated by the ability of either siRNA-AML1/ETO or the DNA methylation inhibitor 5-azacytidine to revert these epigenetic alterations and to restore RA differentiation response in AML1/ETO blasts. Finally, RARβ2 is commonly silenced by hypermethylation in primary AML blasts but not in normal hematopoietic precursors, thus suggesting a role for the epigenetic repression of the RA signaling pathway in myeloid leukemogenesis.
Analysis of 13000 unique Citrus clusters associated with fruit quality, production and salinity tolerance
Authors: Terol Javier , Conesa Ana , Colmenero Jose M , Cercos Manuel , Tadeo Francisco , Agustí Javier , Alós Enriqueta , Andres Fernando , Soler Guillermo , Brumos Javier , Iglesias Domingo J , Götz Stefan , Legaz Francisco , Argout Xavier , Courtois Brigitte , Ollitrault Patrick , Dossat Carole , Wincker Patrick , Morillon Raphael , Talon Manuel
Published: January 2007

Background

Improvement of Citrus, the most economically important fruit crop in the world, is extremely slow and inherently costly because of the long-term nature of tree breeding and an unusual combination of reproductive characteristics. Aside from disease resistance, major commercial traits in Citrus are improved fruit quality, higher yield and tolerance to environmental stresses, especially salinity.

Results

A normalized full length and 9 standard cDNA libraries were generated, representing particular treatments and tissues from selected varieties (Citrus clementina and C. sinensis) and rootstocks (C. reshni, and C. sinenis × Poncirus trifoliata) differing in fruit quality, resistance to abscission, and tolerance to salinity. The goal of this work was to provide a large expressed sequence tag (EST) collection enriched with transcripts related to these well appreciated agronomical traits. Towards this end, more than 54000 ESTs derived from these libraries were analyzed and annotated. Assembly of 52626 useful sequences generated 15664 putative transcription units distributed in 7120 contigs, and 8544 singletons. BLAST annotation produced significant hits for more than 80% of the hypothetical transcription units and suggested that 647 of these might be Citrus specific unigenes. The unigene set, composed of ~13000 putative different transcripts, including more than 5000 novel Citrus genes, was assigned with putative functions based on similarity, GO annotations and protein domains

Conclusion

Comparative genomics with Arabidopsis revealed the presence of putative conserved orthologs and single copy genes in Citrus and also the occurrence of both gene duplication events and increased number of genes for specific pathways. In addition, phylogenetic analysis performed on the ammonium transporter family and glycosyl transferase family 20 suggested the existence of Citrus paralogs. Analysis of the Citrus gene space showed that the most important metabolic pathways known to affect fruit quality were represented in the unigene set. Overall, the similarity analyses indicated that the sequences of the genes belonging to these varieties and rootstocks were essentially identical, suggesting that the differential behaviour of these species cannot be attributed to major sequence divergences. This Citrus EST assembly contributes both crucial information to discover genes of agronomical interest and tools for genetic and genomic analyses, such as the development of new markers and microarrays.
An improved genetic system for detection and analysis of protein nuclear import signals
Authors: Marshall Kris S , Zhang Zhiying , Curran Jennifer , Derbyshire Stephanie , Mymryk Joe S
Published: January 2007

Background

Nuclear import of proteins is typically mediated by their physical interaction with soluble cytosolic receptor proteins via a nuclear localization signal (NLS). A simple genetic assay to detect active NLSs based on their function in the yeast Saccharomyces cerevisiae has been previously described. In that system, a chimera consisting of a modified bacterial LexA DNA binding domain and the transcriptional activation domain of the yeast Gal4 protein is fused to a candidate NLS. A functional NLS will redirect the chimeric fusion to the yeast cell nucleus and activate transcription of a reporter gene.

Results

We have reengineered this nuclear import system to expand its utility and tested it using known NLS sequences from adenovirus E1A. Firstly, the vector has been reconstructed to reduce the level of chimera expression. Secondly, an irrelevant "stuffer" sequence from the E. coli maltose binding protein was used to increase the size of the chimera above the passive diffusion limit of the nuclear pore complex. The improved vector also contains an expanded multiple cloning site and a hemagglutinin epitope tag to allow confirmation of expression.

Conclusion

The alterations in expression level and composition of the fusions used in this nuclear import system greatly reduce background activity in β-galactosidase assays, improving sensitivity and allowing more quantitative analysis of NLS bearing sequences.
Kv1.1 null mice have enlarged hippocampus and ventral cortex
Authors: Persson Ann-Sophie , Westman Eric , Wang Fu-Hua , Khan Firoj Hossain , Spenger Christian , Lavebratt Catharina
Published: January 2007

Background

Mutations in the Shaker-like voltage-gated potassium channel Kv1.1 are known to cause episodic ataxia type 1 and temporal lobe epilepsy. Mice that express a malfunctional, truncated Kv1.1 (BALB/cByJ-Kv1.1

mceph/mceph
) show a markedly enlarged hippocampus and ventral cortex in adulthood.

Results

To determine if mice lacking Kv1.1 also develop a brain enlargement similar to mceph/mceph, we transferred Kv1.1 null alleles to the BALB/cByJ background. Hippocampus and ventral cortex was then studied using in vivo 3D-magnetic resonance imaging and volume segmentation in adult Kv1.1 null mice, BALB/cByJ-Kv1.1

mceph/mceph
, BALB/cByJ-Kv1.1

mceph/+, BALB.C3HeB -Kv1.1
-/+ and wild type littermates. The Kv1.1 null brains had dramatically enlarged hippocampus and ventral cortex. Mice heterozygous for either the null allele or the mceph allele had normal-sized hippocampus and ventral cortex.

Conclusion

Total absence of Kv1.1 can induce excessive overgrowth of hippocampus and ventral cortex in mice with a BALB/cByJ background, while mice with one wild type Kv1.1 allele develop normal-sized brains.