bluuebunny/crossref_metadata_2025 huggingface dataset:
LBP-1.13 LEEP conisation and the risk for preterm birth: new health registry based data from Finland
Authors: Paavonen J , Heinonen A , Gissler M , Tapper A M , Jakobsson M
Published: July 2011

Objectives

To study whether the increasing severity of cervical intraepithelial neoplasia (CIN) by LEEP (loop electrosurgical excicion procedure) cone correlates with the risk for preterm birth. We also wanted to study whether the time period from LEEP or repeat LEEP correlates with the risk.

Methods

Retrospective register-based study from Finland during 1997–2009. We collected data from the Hospital Discharge Register. We linked the data with data from the Finnish Medical Birth Register. The study population consisted of 20 011 women who had LEEP during 1998–2009 and a subsequent delivery during 1997–2009. Controls were women with no previous LEEP (n=430 975). The main outcome measure was preterm birth (<37 gestational weeks) rate.

Results

The risk for preterm birth was increased after LEEP (OR 1.82, CI 1.62 to 2.03). In primiparous women this risk was slightly lower OR 1.61 (CI 1.42 to 1.83). Repeat LEEP was associated with almost threefold risk for preterm birth (OR 2.71, CI 1.98 to 3.69). Increasing severity of CIN did not correlate with the preterm birth rate. LEEP for carcinoma in situ or microinvasive cancer, however, increased the risk threefold (OR 3.25, CI 1.92 to 5.50). The risk was also increased for HPV-related non-CIN lesions (OR 2.55, CI 1.72 to 3.78). Time period since LEEP was not associated with the risk for preterm birth. Adjusting for maternal age, parity, socio-economic status, or marital status, or history of previous preterm birth did not change the results.

Conclusion

The risk for preterm birth was increased after LEEP, but was not associated with the severity of CIN. Repeat LEEP had highest risk. Unnecessary LEEP should be avoided especially among young women.
LBP-1.14 Genital warts: Canadians' perception and health related behaviours
Authors: Steben M , Labelle D
Published: July 2011

Background

A high level of anxiety is associated with a diagnosis of genital warts but health-related behaviours are less well known.

Objective

To gauge the perceptions of Canadians towards genital warts and associated treatments.

Methods

A survey supported by an unrestricted grant from Graceway Canada was conducted in February 2011 by Leger Marketing using their online panel (LegerWeb). It included 17 questions (2 multiple-choice, 15 4-point rating from strongly agree to strongly disagree]) relating to genital wart perception plus nine demographic questions.

Results

The survey was completed by 1520 Canadian adults aged 18–75+ years, of which 52% were female. Fifty-two per cent of respondents stated that they would monitor an unrecognised spot on their genitals and only seek medical assistance if it did not go away. Only 43% said they would stop having sex until the spots were gone. Concerns of being judged by friends/family were high (44%). Regarding prevention, 32% of respondents believed that monogamy would protect against genital warts, and 25% believed they are not at risk if they use a condom. Treatment preference was in favour of a cream rather than an invasive treatment (58%), particularly among younger (67%) and male respondents (63%). Over 60% would worry that genital warts could not be resolved. Women were less likely to believe that genital warts could be cured (13% vs 23%), and more likely to believe that they would recur (46% vs 42%) see Abstract LBP-1.14 Figure 1.

Conclusion

Among Canadians, genital warts were associated with a fair degree of social stigma and worries regarding their resolution, and future recurrences. Non-invasive treatment options were preferred.

Abstract LBP-1.14 Figure 1
LBO-1.3 Syphilis infection and associated behaviours among transgender women, Chicago 2010
Authors: Gratzer B , Hotton A , Pineda M , Pohl D , Martinez L
Published: July 2011

Background

Transgender women are an underserved and understudied population with unique medical and behavioural risk profiles. High rates of STIs and HIV in this population have been reported, although accurately quantifying STI rates and associated risks is difficult because of limitations in measurement of gender identity, lack of standardised reporting measures, and conflation between Men who Have Sex with Men (MSM) and transgender identities. In 2009 we reported a substantial increase in syphilis among transgender women at our clinic (from two cases in 4 years to ten cases in 1 year); in 2010 we identified 20 new cases, another substantial increase. We sought to describe morbidity and behavioural characteristics of these cases to better understand trends among this population.

Methods

Data were gathered using clinic-based sentinel surveillance systems and through abstraction of Interview Records completed upon DIS interview.

Results

Transgender women represented an increasing proportion of total syphilis cases identified from 2009 (3.7% or 10/269) to 2010 (6.4% or 20/313). The 20 cases identified in 2010 were among 19 transgender women; one client was re-infected. Of these, 2 (10%) were primary, 12 (60%) were secondary, 5 (25%) were early latent, and 1 (5%) was latent of unknown duration syphilis. The mean age increased slightly from 21.4 years (range 19–24) in 2009 to 24.9 years (range 19–41) in 2010. Reported race/ethnicity included: 13 (65%) non-Hispanic black, 3 (15%) Hispanic, 2 (10%) non-Hispanic white, 1 (5%) Asian/Pacific Islander and 1 (5%) American Indian/Alaskan Native. HIV co-infection was similar to rates observed in Men who Have Sex with Men (MSM) populations (60%); 25% of HIV-positive clients had been diagnosed in the prior year. Forty-five per cent had a history of STI (non-HIV). High rates of transient housing (30%), unemployment (55%), incarceration (25%), and transactional sex (40%) in the prior 12 months were reported. Median number of sex partners in the past year was 10 (range 0–60). No common sex partners were named during case investigation interviews during 2009 or 2010.

Conclusions

Increases in syphilis among transgender women in Chicago highlight a need for enhanced screening and targeted prevention messages for this population. High levels of risk and HIV co-infection reflect potential for ongoing transmission of both HIV and other STIs.
LBO-1.4 Increasing macrolide resistance inMycoplasma genitalium
Authors: Anagrius C , Loré B , Jensen J S
Published: July 2011

Background

To evaluate therapy outcome inM genitaliuminfection with standard chlamydia treatment doxycyclin 9 days and azithromycin 1 g stat compared to extended azithromycin 15 g for 5 days and to evaluate macrolide resistance.

Methods

Patients attending the STD-clinic in Falun, Sweden between January 1998 and December 2005 with a positive PCR test forM genitaliumroutinely had a test of cure. Response was determined to doxycycline, azithromycin 1 g as a single dose and 15 g extended treatment primary and secondary when persistence after doxycycline. Macrolide resistance was monitored at base as well as after treatment in those testing positive after treatment with azithromycin. Macrolide resistance also was monitored yearly 2006–2010 in patients with newly detectedM genitaliuminfection.

Results

Totally 313/407 (77%) had a test of cure, 254/313 (81%) within 12 weeks. The eradication rate with doxycycline was 43% totally, 46% for women and 38% for men, with azithromycin 1 g 92% totally, 96% for women and 89% for men and with azithromycin extended dosage 96% totally, 100% for women and 93% for men. Confirmed macrolide resistance developed in 7/7 (100%) of those testing positive after azithromycin 1 g. In 2006–2007 we found no, in 2008 and 2009 1/year and in 2010 11 patients with macrolide resistance in newly detectedM genitalium.

Conclusions

These findings confirms the results from other studies that doxycycline is inefficient in eradicating infection withM genitalium. Although the treatment outcome with azithromycin 1 g was not significantly lower than with extended dosage for 5 days it was in this study associated with 100% induced macrolide resistance in those with treatment failure. A remarkable higher proportion of macrolide resistance in 2010 than earlier years was found. We will try to monitor yearly prescription of azithromycin 1 g in our county and all Sweden last years. Is there an increase explaining the higher proportion 2010? Azithromycine 1 g should be avoided as recommended therapy forM genitaliumas well as for chlamydia and non-gonococcal urethritis. Specific diagnostics forM genitaliumas well as monitoring of resistance is urgent.
LBP-1.02 Acceptability and appeal of internet-based STI and HIV testing among a sample of gay men and clients attending STI clinics in British Columbia
Authors: Hottes T S , Gilbert M , Bondyra M , Haag D , Shoveller J
Published: July 2011

Background

Several jurisdictions globally have implemented internet-based STI and HIV testing with good uptake and reach into untested populations. In British Columbia, a similar program is under development to offer online access to chlamydia, gonorrhoea, syphilis, and HIV testing. This program aims to increase the frequency of testing in individuals at risk of infection and ease demand on clinic-based services by providing an accessible option for screening asymptomatic persons. We conducted a series of focus groups in spring 2011 to determine the acceptability of various aspects of the internet testing model and of the service overall.

Methods

Two types of prospective internet testing clients living in the Vancouver area were recruited for focus groups: self-identified gay/bisexual/two-spirit men (hereafter “gay men”) and STI clinic clients. Participants were presented with a brief description of the internet testing model, after which a structured interview guide was used to address the following domains: willingness to provide personal information online, ways to engender trust in the service, comfort with different ways of delivering results, interest in specific features, appeal of the service, and willingness to use the service.

Results

Most of the 31 participants to-date (ages 21–70 years) were gay men (81%) and reported post-secondary education (74%). All were self-described active internet users and had been tested previously for HIV or other STI. Overall, the concept of internet testing was thought to be acceptable and most participants expressed interest in using the service when it becomes available. Participants indicated that internet testing would be convenient and could enhance the accessibility of STI testing, particularly for people living outside of urban centres. Some noted that an internet approach would also have the potential to allay embarrassment that can arise when seeking STI testing in a face-to-face clinical setting. There was strong interest in assuring anonymity for those using the proposed internet testing service. Participants also emphasised the importance of providing information related to HIV diagnosis and referrals to peer support and counselling for those waiting for and receiving test results.

Conclusions

Internet testing was deemed to be acceptable and desirable and appears to hold promise as a means to complement to existing clinic-based STI testing services in Vancouver, Canada.
LBP-1.03 “No one was there to care for us” Ashraya's response to its members' needs in terms of care and support
Authors: Chevrier C
Published: July 2011

Background

Sex workers (SWs) have been identified as a “high-risk group” and considerable effort has been invested in promoting “safer sex” among this group. However, their specific concerns and identities vanish in broader public health policy discussions related to treatment and particularly care. Ashodaya Samithi, a SWs organisation based in Mysore, Karnataka, has been providing extensive care and support (C&S) services to SWs and “non-SWs” living with HIV through their sub-wing organisation, Ashraya, since 2008. Considering the enduring stigma attached to SWs, what motivates individuals to seek health services from Ashraya?

Methods

40 in-depth interviews (including 10 with non-SWs) were conducted with Ashraya members in 2011 to explore how Ashraya responds to the needs of its members in terms of C&S. Content analysis of the transcripts was completed to sort out themes.

Results

Analysis shows that in spite of scarce resources, the accessibility, effective outreach efforts, and commitment and reliability of Ashraya's volunteers are major components of its growing popularity.

Conclusions

In the near-absence of non-discriminatory, affordable C&S for people living with HIV/AIDS, Ashraya offers much needed relief to its members. The potential role of SWs community-based organisations in providing C&S, which goes beyond safer sex promotion, needs to be accounted for within national-level policy planning and in evaluating existing programs.
EFFICIENCY DROOP IN GaInN HIGH-POWER LIGHT-EMITTING DIODES
Authors: SCHUBERT MARTIN F. , KIM JONG KYU
Published: July 2011

GaN -based light-emitting diodes suffer from high-current loss mechanisms that lead to a significant decrease in internal quantum efficiency at high drive currents. This phenomenon, known as "efficiency droop," is a major problem for solid-state lighting applications, in which light-emitting diodes are driven at high currents to deliver large optical powers. Although substantial effort has been invested to uncover the physical origin and mitigate the effects of efficiency droop, there is still a lack of consensus on the dominant mechanism responsible. In this article, we review several mechanisms that have been proposed as explanations of efficiency droop, including junction heating, carrier delocalization, Auger recombination, and electron leakage from the active region. In addition, device structures intended to mitigate the droop-causing mechanism – (i) thick quantum wellsl, (ii) enhanced hole-injection efficiency structures, and (iii) polarization-matched active region – are discussed.
LIGHT EMITTING DIODE DRIVERS AND CONTROL
Authors: WINDER STEVE
Published: July 2011

This paper outlines the various driving and control techniques for Light Emitting Diodes (LEDs). LEDs should be driven from a constant current source. High power LEDs are usually driven from a switching regulator, for reasons of efficiency. The types of drivers described include Buck (step-down), Boost (step-up) and Buck-Boost (step-up or step-down). Isolated drivers and Power Factor Correction (PFC) circuits are also described. This brief paper can only describe the basic outline of these circuits, but this should be sufficient to allow the basic principles to be understood.
k-ESSENCE AND TACHYONS IN BRANEWORLD COSMOLOGY
Authors: CHIMENTO LUIS P. , RICHARTE MARTÍN G.
Published: July 2011

We investigate a k-essence field localized on the brane evolving linearly with the cosmological time for some kinetic functions and consider the atypical k-essence model for linear and nonlinear k-fields in Friedmann–Robertson–Walker (FRW) cosmology. In the former case the k-field is driven by an inverse quadratic polynomial potential and the solutions exhibit several different behaviors which include expanding, contracting and bouncing universes as well as a model with a finite time span, some of them ending in a big crunch or a big rip. In the latter case we find the potential and show that the atypical k-essence model is dynamically incomplete. Particularly, by selecting the extended tachyonic kinetic functions we analyze the high and low energy limits of our model, obtaining the nearly power-law solution. We introduce a tachyon field with negative energy density and show that the universe evolves between two singularities.
THE ELECTRIC CABLE DIFFERENTIAL LEG: A NOVEL DESIGN APPROACH FOR WALKING AND RUNNING
Authors: HURST JONATHAN W.
Published: July 2011

This paper documents the mechanical system of the electric cable differential (ECD) leg, and its incorporation into a monopod hopping robot named "Thumper" and a bipedal robot named "Mabel." The ECD leg is designed with physical springs and other passive dynamics to match a mathematically simple, bioinspired mass-spring model, which can exhibit robust and economic walking and running gaits. With this design approach, existing spring-mass theory-based controllers can be used to control the robot. The scientific goals of this work focus on finding an energetically optimal leg stiffness for running, and results from experimentation on Thumper and on a simulation of Thumper are presented.
A COMPUTATIONAL INTELLIGENT APPROACH TO KINEMATICS PROBLEMS IN ROBOTICS AND COMPUTER ANIMATION
Authors: TAROKH MAHMOUD , WANG MINJUAN
Published: July 2011

The paper presents a novel method for solving the kinematics problems in real time for fast-moving robot manipulators, animation characters, and hexapod robots. The method uses certain properties of the kinematics map and is based on spatial decomposition, classification with fuzzy logic, and neural network representation of data that are performed during an off-line process. As a result of the preprocessing, the online time for computing the kinematics is extremely small making it possible to perform real-time operations. Examples are provided to demonstrate the performance of the method.
THE ROLE OF SELF-CONSTRUAL ON PREFERRED COMMUNICATION STYLES WITH HUMANOID ROBOTS
Authors: KIM MIN-SUN , GONG LI , SAITO NICOLE , NISHIGAYA KIMBERLY , CABICO MARJORIE , LAFONTAINE PASCALE
Published: July 2011

Research on human–human communication has identified that people apply different constraints in communication with each other. Application of such constraints as social concerns over feeling, imposition, and disapproval and task concerns over clarity and effectiveness has also been found to be influenced by people's self-construal, being independent or interdependent. Do these constraints and individual difference in self-construal matter in communication with humanoid robots? This study uses the theoretical framework of communication constraints to compare whether or not people of different self-construals apply social-oriented and task-oriented constraints differently to humanoid social robot targets. A total of 161 students from the University of Hawaii at Manoa participated in the study. The participants completed a questionnaire that determined their concern for the five communication constraints (feelings, nonimposition, disapproval, clarity, and effectiveness) in situations involving robots, as well as scales measuring self-construal. The results show interdependent self-construal related significantly with the concerns over avoiding hurting the humanoid's feelings, avoiding inconveniencing the humanoid robot, and avoiding being disliked by the humanoid robot. On the other hand, independent self-construal related significantly with the concern over clarity in communicating with the humanoid robot. However, self-construal did not influence one's concern of effectiveness (a task-oriented constraint) in interaction with humanoid robots. The results of the research offer new insight into the linkage between self-construal, a cultural concept at the individual level, and how human–robot communication is psychologically structured and constrained.
Teledermatology: From Prevention to Diagnosis of Nonmelanoma and Melanoma Skin Cancer
Authors: Fabbrocini G. , De Vita V. , Pastore F. , D'Arco V. , Mazzella C. , Annunziata M. C. , Cacciapuoti S. , Mauriello M. C. , Monfrecola A.
Published: July 2011

Telemedicine is a rapidly developing application of clinical medicine where medical information is transferred through interactive audiovisual media for the purpose of consulting remote medical procedures or examinations, reducing the time of consultation for patients. Teledermatology as an application of telemedicine was developed in 1995: it turns out to be a gradually more ordinary mean of delivering dermatologic healthcare worldwide and will almost certainly have a greater medical function in the future. In particular, teledermatology can aid in the prevention and diagnosis of nonmelanoma and melanoma skin cancer; telemedicine and teledermatology offer the opportunity to make available consultations with experts also by long distance. Overall, patients seem to accept teledermatology, considering it as an excellent mean to obtain healthcare, particularly in those areas with no expert dermatologists available. Clinicians have also generally reported affirmative experiences with teledermatology in the skin cancer field. Further studies focusing on cost effectiveness, patient outcomes, and patient and clinician satisfaction will facilitate to delineate the potential of teledermatology as a mean of prevention and diagnosis of nonmelanoma and melanoma skin cancer.
Systemic Mastocytosis Associated with Splenic Marginal Zone Lymphoma with Villous Lymphocytes
Authors: Fernández-Torres R. , Verea M. M. , Álvarez A. , Torres P. , Fonseca E.
Published: July 2011

The development of a second haematological disease during the course of systemic mastocytosis is a well-known phenomenon. In most of the cases, they consist of myelodysplasia or myeloproliferative disorders. The association with lymphoproliferative disorders has also been described, but it is uncommon and the relationship is not well established. We report a patient diagnosed with systemic mastocytosis who three years later developed a splenic marginal zone lymphoma with villous lymphocytes.
Ability of Different Measures of Adiposity to Identify High Metabolic Risk in Adolescents
Authors: Moreira Carla , Santos Rute , Vale Susana , Santos Paula C. , Abreu Sandra , Marques Ana I. , Soares-Miranda Luísa , Mota Jorge
Published: July 2011

Introduction. This study aimed to evaluate the screening performance of different measures of adiposity: body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) for high metabolic risk in a sample of adolescents.Methods. A cross-sectional school-based study was conducted on 517 adolescents aged 15–18, from the Azorean Islands, Portugal. We measured fasting glucose, insulin, total cholesterol (TC), HDL-cholesterol, triglycerides, and systolic blood pressure. HOMA and TC/HDL-C ratio were calculated. For each of these variables, a Z-score was computed by age and sex. A metabolic risk score (MRS) was constructed by summing the Z-scores of all individual risk factors. High risk was considered when the individual had ≥1SD of this score. Receiver-operating characteristics (ROC) were used.Results. Linear regression analyses showed that, after adjusting for age and pubertal stage, all different measures of adiposity are positively and significantly associated with MRS in both sexes, with exception of WHtR for boys. BMI, WC, and WHtR performed well in detecting high MRS, indicated by areas under the curve (AUC), with slightly greater AUC for BMI than for WC and WHtR in both sexes.Conclusion. All measures of adiposity were significantly associated with metabolic risk factors in a sample of Portuguese adolescents.
Liaison Old Age Psychiatry Service in a Medical Setting: Description of the Newcastle Clinical Service
Authors: Mukaetova-Ladinska E. B. , Cosker G. , Coppock M. , Henderson M. , Ali Ashgar Y. , Hill A. , Scully A. , Robinson D. , Sells K. , Brotherton S. , Lowthian C.
Published: July 2011

Liaison Old Age Psychiatry services (LOAP) have begun to emerge in the UK and further development of the service is supported by the latest health policies. Since qualitative and quantitative studies in this area are lacking, we have undertaken a detailed quantitative prospective review of referrals to the Newcastle LOAP to evaluate the clinical activity of the service. We report high referral rates and turnover for the LOAP service. Reasons for referral are diverse, ranging from requests for level of care and capacity assessments and transfer to other clinical services to management of behaviour, diagnosis, and treatment. We outline the value of a multidisciplinary model of LOAP activity, including the important role of the liaison nursing team, in providing a rapid response, screening, and followup of high number of clinical referrals to the service.
Polynomial Roots and Calabi-Yau Geometries
Authors: He Yang-Hui
Published: July 2011

The examination of roots of constrained polynomials dates back at least to Waring and to Littlewood. However, such delicate structures as fractals and holes have only recently been found. We study the space of roots to certain integer polynomials arising naturally in the context of Calabi-Yau spaces, notably Poincaré and Newton polynomials, and observe various salient features and geometrical patterns.
A Study on Becker′s Univalence Criteria
Authors: Darus Maslina , Faisal Imran
Published: July 2011

We study univalence properties for certain subclasses of univalent functions 𝔎, 𝔎2, 𝔎3, and S(p), respectively. These subclasses are associated with a generalized integral operator. The extended Becker‐typed univalence criteria will be studied for these subclasses.
Shunt Active and Series Active Filters-Based Power Quality Conditioner for Matrix Converter
Authors: Paul P. Jeno
Published: July 2011

This paper proposes a series active filter and shunt active filter to minimize the power quality impact present in matrix converters instead of passive filter. A matrix converter produces significant harmonics and nonstandard frequency components into load. The proposed system compensates the sag and swell problems efficiently in matrix converter. The proposed system has been tested and validated on the matrix converter using MATLAB/Simulink software. Simulated results confirm that the active power filters can maintain high performance for matrix converter.
Effect ofMucuna pruriensSeed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring toNaja sputatrix(Javan Spitting Cobra) Venom
Authors: Fung Shin Yee , Tan Nget Hong , Sim Si Mui , Aguiyi John C.
Published: July 2011

Mucuna pruriensLinn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated withM. pruriensseed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects ofNaja sputatrix(Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions ofNaja sputatrixvenom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest thatM. pruriensseed may contain novel cardioprotective agent with potential therapeutic value.
VDR Expression on Circulating Endothelial Progenitor Cells in Dialysis Patients Is Modulated by 25(OH)D Serum Levels and Calcitriol Therapy
Authors: Cianciolo Giuseppe , La Manna Gaetano , Cappuccilli Maria L. , Lanci Nicole , Della Bella Elena , Cuna Vania , Dormi Ada , Todeschini Paola , Donati Gabriele , Alviano Francesco , Costa Roberta , Bagnara Gian Paolo , Stefoni Sergio
Published: July 2011

Background/Aims: Vitamin D deficiency is associated with endothelial dysfunction in uremic patients, possibly by the impairment in the number and function of endothelial progenitor cells (EPCs). In 89 hemodialysis patients, we investigated the factors associated with the number of circulating EPCs (CD34+/CD133+/KDR+ and CD34+/CD133–/KDR+ cells), the presence of VDR and the determinants of VDR expression on EPCs, in particular in calcitriol therapy. Methods: EPC counts, percentages of VDR-positive EPCs and VDR expression were assessed by flow cytometry. Cells isolated from a subgroup of patients were cultured to analyze colony-forming units, specific markers expression and a capillary-like structure formation. Results/Conclusions: Our study demonstrates the presence of VDR on EPCs. In our dialysis patients, the parameters studied on both CD34+/CD133+/KDR+ and CD34+/CD133–/KDR+ cells, in particular VDR expression, seem to be influenced by uremia-related factors, including anemia, inflammation, diabetes, 25(OH)D serum levels and calcitriol therapy.
QT Interval and QT Dispersion in Patients Undergoing Hemodialysis: Revisiting the Old Theory
Authors: Alabd Mohamed A. , El-Hammady Walid , Shawky Ahmed , Nammas Wail , El-Tayeb Mohamed
Published: July 2011

Aims: We sought to explore the response of the corrected QT (QTc) interval duration and QT dispersion (QTD) to hemodialysis. Methods: We enrolled 50 patients with end-stage renal disease undergoing regular hemodialysis. Blood samples were drawn for measurement of serum electrolytes, and a 12-lead ECG was performed to measure the QTc interval duration and QTD, immediately before and just after dialysis sessions. Results: The mean age of the cohort was 42.8 ± 12.2 years (58% males). Both the QTc duration and QTD showed marked variability after hemodialysis. A significant correlation was found between the decrease of both serum potassium and magnesium levels after dialysis and the post-dialysis QTc interval duration, with Pearson’s correlation coefficients r = –0.43 and r = –0.34, p = 0.002 and p = 0.01, respectively. Patients with a post-dialysis increase of QTc interval duration had a significantly higher percentage of reduction of serum potassium (p = 0.029), whereas patients with a post-dialysis increase of QTD had a significantly higher percentage of reduction of serum magnesium (p = 0.03). Conclusion: Our findings suggest a highly variable response of the QTc interval duration and QTD to hemodialysis. The post-dialysis QTc interval duration inversely correlated with the decrease of both serum potassium and magnesium levels after dialysis.
Efficacy of Flour Fortification with Folic Acid in Women of Childbearing Age in Iran
Authors: Abdollahi Z. , Elmadfa I. , Djazayery A. , Golalipour M.J. , Sadighi J. , Salehi F. , Sadeghian Sharif S.
Published: July 2011

Background: Flour fortification with folic acid is one of the main strategies for improving folate status in women of childbearing age. No interventional trial on the efficacy of folic acid fortification has been conducted so far in Iran. Objectives: To study the effects of flour fortification with folic acid on any reduction in neural tube defects (NTDs) and folate status of women of childbearing age. Methods: In a longitudinal hospital-based study, 13,361 postpartum women were studied after admission for childbirth before and after fortification. In addition, two cross-sectional surveys were conducted before (2006) and after flour fortification (2008). The cluster sampling method was used and 580 women, 15–49 years old, were studied as a representative sample of Golestan province in the north of Iran. Fasting blood samples were collected to measure serum vitamin B12, folate and plasma homocysteine. Sociodemographic data, health characteristics and dietary intake were determined. Results: The mean daily intakes of folate from natural food before and after flour fortification were 198.3 and 200.8 µg/day, respectively. The total folate intake increased significantly from 198.3 to 413.7 µg/day after fortification (p < 0.001). Folate intake increased by an average of 226 µg/day from fortified bread. The mean serum folate level increased from 13.6 to 18.1 nmol/l; folate deficiency decreased from 14.3 to 2.3% (p < 0.001). The incidence rate of NTDs declined by 31% (p < 0.01) in the post-fortification period (2.19 per 1,000 births; December 2007 to December 2008) compared to the pre-fortification period (3.16 per 1,000 births; September 2006 to July 2007). Conclusions: Implementation of mandatory flour fortification with folic acid can lead to a significant increase in serum folate and a significant decrease in NTDs.
Circulation: Arrhythmia and Electrophysiology
Editors' Picks
Authors:   The Editors
Published: July 2011

The following articles are being highlighted as part of
Circulation
's Topic Review series. This series will summarize the most important manuscripts, as selected by the editors, published in
Circulation
and the
Circulation
subspecialty journals. The studies included in this article represent the “Editors' Picks” for each issue of
Circulation: Arrhythmia and Electrophysiology
published in 2009 and 2010.
Does Semantic Context Benefit Speech Understanding through “Top–Down” Processes? Evidence from Time-resolved Sparse fMRI
Authors: Davis Matthew H. , Ford Michael A. , Kherif Ferath , Johnsrude Ingrid S.
Published: July 2011

When speech is degraded, word report is higher for semantically coherent sentences (e.g., her new skirt was made of denim) than for anomalous sentences (e.g., her good slope was done in carrot). Such increased intelligibility is often described as resulting from “top–down” processes, reflecting an assumption that higher-level (semantic) neural processes support lower-level (perceptual) mechanisms. We used time-resolved sparse fMRI to test for top–down neural mechanisms, measuring activity while participants heard coherent and anomalous sentences presented in speech envelope/spectrum noise at varying signal-to-noise ratios (SNR). The timing of BOLD responses to more intelligible speech provides evidence of hierarchical organization, with earlier responses in peri-auditory regions of the posterior superior temporal gyrus than in more distant temporal and frontal regions. Despite Sentence content × SNR interactions in the superior temporal gyrus, prefrontal regions respond after auditory/perceptual regions. Although we cannot rule out top–down effects, this pattern is more compatible with a purely feedforward or bottom–up account, in which the results of lower-level perceptual processing are passed to inferior frontal regions. Behavioral and neural evidence that sentence content influences perception of degraded speech does not necessarily imply “top–down” neural processes.
Conserving Digital Art for Deep Time
Authors: Marchese Francis T.
Published: July 2011

Displaying digital art in the late twentieth and early twenty-first centuries is already proving to be a challenge. Exhibiting this same art in the distant future will depend upon new thinking and practices developed today by artists, conservators, and curators. Established software engineering methods for dealing with aging systems can provide a new model for the conservation of digital art, and a foundation for the enhancement of art-historical scholarship. Artists with an interest in a more refined approach to the programming that underpins their work will also be interested in software engineering concepts.
Art and Code: The Aesthetic Legacy of Aldo Giorgini
Authors: García Esteban , Whittinghill David
Published: July 2011

In 1975 Aldo Giorgini developed a software program in FORTRAN called FIELDS, a numerical visual laboratory devoted entirely to art production. Working extensively as both artist and scientist, Giorgini was one of the first computer artists to combine software writing with early printing technologies, leaving an aesthetic legacy in the field of the digital arts. His individual process was innovative in that it consisted of producing pen-plotted drawings embellished by the artist's hand with painting, drawing, and screen-printing. This paper is the product of a multi-year study of Giorgini's primary source materials provided by his estate. The authors examine the methods used by Giorgini during the 1970s that allowed him to create computer-aided art, in the hope that publishing this work will ensure that future generations of digital artists, technologists and scientists can be educated in Giorgini's contribution to the history of the digital arts.
Diagnosis of the Warm Rain Process in Cloud-Resolving Models Using Joint CloudSat and MODIS Observations
Authors: Suzuki Kentaroh , Stephens Graeme L. , van den Heever Susan C. , Nakajima Takashi Y.
Published: July 2011

This study examines the warm rain formation process in global and regional cloud-resolving models. Methodologies developed to analyze CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations are employed to investigate the cloud-to-precipitation processes and are applied to model results for comparisons with corresponding statistics from the observations. Three precipitation categories of no precipitation, drizzle, and rain are defined according to nonattenuated near-surface radar reflectivity, and their fractional occurrences and the probability of precipitation are investigated as a function of cloud properties such as droplet size, optical thickness, droplet number concentration, and liquid water path. The comparisons reveal how the models are qualitatively similar to, but quantitatively different from, observations in terms of cloud-to-rainwater conversion processes. Statistics from one model reveal a much faster formation of rain than observed, with drizzle occurrence being much less frequent, whereas statistics from the other model illustrate rain formation closer to satellite observations but still faster formation of drizzle water. Vertical profiles of radar reflectivity that are rescaled as a function of in-cloud optical depth and classified according to particle size are also compared. The results show that each model indicates systematically faster formation of rain and drizzle, respectively, than observed in vertical profiles although they indicate that the cloud-to-rain transitions are qualitatively similar to observations. These results characterize the model behavior in terms of warm cloud microphysics and then point to a possible area of model improvement for more realistic representation of warm rain formation processes.
Eddy Diffusivities for Momentum and Heat in the Upper Troposphere and Lower Stratosphere Measured by MU Radar and RASS, and a Comparison of Turbulence Model Predictions
Authors: Ueda Hiromasa , Fukui Tetsuo , Kajino Mizuo , Horiguchi Mitsuaki , Hashiguchi Hiroyuki , Fukao Shoichiro
Published: July 2011

Recently, middle- and upper-atmosphere Doppler radar (MU radar) has enabled the measurement of middle-atmosphere turbulence from radar backscatter Doppler spectra. In this work, eddy diffusivities for momentum Km in the upper troposphere and lower stratosphere during clear-air conditions were derived from direct measurements of the Reynolds stress and vertical gradient of mean wind velocity measured by MU radar. Eddy diffusivity for heat Kh below 8 km was determined from measurements of temperature fluctuations by the Radio Acoustic Sounding System (RASS) attached to the MU radar. The eddy diffusivity for momentum was on the order of 10 m2 s−1 in the upper troposphere and decreased gradually in the stratosphere by an order of magnitude or more. The eddy diffusivity for heat was almost of the same order of magnitude as Km.

Estimates of eddy diffusivity from the radar echo power spectral width give fairly good values compared with the direct measurement of Km. Applicability of three turbulence models—the spectral width method, the k–ɛ model modified for stratified flows, and the algebraic stress model—were also examined, using radar observation values of turbulent kinetic energy k and turbulent energy dissipation rate ɛ together with atmospheric stability observations from rawinsonde data. It is concluded that the algebraic stress model shows the best fit with the direct measurement of Km, even in the free atmosphere above the atmospheric boundary layer once k and ɛ values are obtained from observations or a model.
Persistent Circulation Regimes and Preferred Regime Transitions in the North Atlantic
Authors: Franzke Christian , Woollings Tim , Martius Olivia
Published: July 2011

The persistent regime behavior of the eddy-driven jet stream over the North Atlantic is investigated. The North Atlantic jet stream variability is characterized by the latitude of the maximum lower tropospheric wind speed of the 40-yr ECMWF Re-Analysis (ERA-40) data for the period 1 December 1957–28 February 2002. A hidden Markov model (HMM) analysis reveals that the jet stream exhibits three persistent regimes that correspond to northern, southern, and central jet states. The regime states are closely related to the North Atlantic Oscillation and the eastern Atlantic teleconnection pattern. The regime states are associated with distinct changes in the storm tracks and the frequency of occurrence of cyclonic and anticyclonic Rossby wave breaking. Three preferred regime transitions are identified, namely, southern to central jet, northern to southern jet, and central to northern jet. The preferred transitions can be interpreted as a preference for poleward propagation of the jet, but with the southern jet state entered via a dramatic shift from the northern state. Evidence is found that wave breaking is involved in two of the three preferred transitions (northern to southern jet and central to northern jet transitions). The predictability characteristics and the interannual variability in the frequency of occurrence of regimes are also discussed.
Impact of SSTA in the East Indian Ocean on the Frequency of Northwest Pacific Tropical Cyclones: A Regional Atmospheric Model Study
Authors: Zhan Ruifen , Wang Yuqing , Wu Chun-Chieh
Published: July 2011

The impact of the sea surface temperature anomaly (SSTA) in the East Indian Ocean (EIO) on the tropical cyclone (TC) frequency over the western North Pacific (WNP) and the involved physical mechanisms are examined using the International Pacific Research Center (IPRC) Regional Atmospheric Model (iRAM) driven by the reanalysis and the observed SSTs. The model reproduces generally quite realistic climatic features of the WNP TC activity, including the interannual variability of the WNP TC genesis frequency, the geographical distributions of TC genesis and frequency of occurrence. In particular, the model reproduces the observed statistical (negatively correlated) relationship between the WNP TC frequency and the EIO SSTA, as recently studied by Zhan et al.

The experiments with artificially imposed SSTA in the EIO in the year 2004 with normal EIO SST and WNP TC activity confirm that the EIO SSTA does affect the TC genesis frequency in the entire genesis region over the WNP by significantly modulating both the western Pacific summer monsoon and the equatorial Kelvin wave activity over the western Pacific, two major large-scale dynamical controls of TC genesis over the WNP. Additional sensitivity experiments are performed for two extreme years: one (1994) with the highest and one (1998) with the lowest TC annual frequencies in the studied period. The results reveal that after the EIO SSTAs in the two extreme years are removed, the TC frequency in 1998 is close to the climatological mean, while the excessive TCs in 1994 are still simulated. The model results suggest that the warm EIO might be a major factor contributing to the unusually few TCs formed over the WNP in 1998, but the cold EIO seemed to contribute little to the excessive WNP TCs in 1994.
On the Relationship between Uncertainties in Tropical Divergence and the Hydrological Cycle in Global Models
Authors: Hagos Samson , Leung L. Ruby
Published: July 2011

A survey of tropical divergence from three GCMs, three global reanalyses, and four in situ soundings from field campaigns shows the existence of large uncertainties in the ubiquity of shallow divergent circulation as well as the depth and strength of the deep divergent circulation. More specifically, only two out of the three GCMs and three global reanalyses show significant shallow divergent circulation, which is present in all in situ soundings, and of the three GCMs and three global reanalyses, only two global reanalyses have deep divergence profiles that lie within the range of uncertainty of the soundings. The relationships of uncertainties in the shallow and deep divergent circulation to uncertainties in present-day and projected strength of the hydrological cycle from the GCMs are assessed. In the tropics and subtropics, deep divergent circulation is the largest contributor to moisture convergence that balances the net precipitation (precipitation minus evaporation), and intermodel differences in the present-day simulations carry over onto the future projections. In comparison to the soundings and reanalyses, the GCMs are found to have deeper and stronger divergent circulation. While these two characteristics of GCM divergence affect the strength of the hydrological cycle, they tend to compensate for each other so that their combined effect is relatively modest.
Importance of Circulation Changes to Atlantic Heat Storage Rates on Seasonal and Interannual Time Scales
Authors: Piecuch Christopher G. , Ponte Rui M.
Published: July 2011

Ocean heat budgets and transports are diagnosed to elucidate the importance of general circulation changes to Atlantic Ocean heat storage rates. The focus is on low- and midlatitude regions and on seasonal and interannual time scales. An estimate of the ocean state over 1993–2004, produced by a coarse-resolution general circulation model fit to observations via the method of Lagrange multipliers, is used. Meridional heat transports are first decomposed into contributions from time-mean and time-variable velocity and temperature and second from zonally symmetric baroclinic (overturning, including Ekman) and zonally asymmetric (gyre and other spatially correlated) circulations. Heat storage rates are then ascribed to ocean–atmosphere heat exchanges, diffusive mixing, and advective processes related to the various components of the meridional heat transport. Results show that seasonal heat storage changes generally represent a local response to surface heat inputs, but seasonal advective changes are also important near the equator. Interannual heat storage rate anomalies are mostly due to advection in tropical regions, whereas both surface heat fluxes and advection contribute at higher latitudes. Low-latitude advection can be primarily attributed to zonally symmetric baroclinic circulations, but temperature variations and zonally asymmetric flows can contribute elsewhere. A relationship between interannual heat storage rates in the equatorial Atlantic’s top 100 m and meridional heat transport associated with the zonally symmetric baroclinic flow is observed; however, due in part to the role of shallow advective processes at these latitudes, any direct relationship between sea surface temperature variability and heat transport changes associated with intermediate or deep meridional overturning circulations is not clear.