bluuebunny/crossref_metadata_2025 huggingface dataset:
Metformin-Associated Lactic Acidosis; Escitalopram-Related Rhabdomyolysis; Adalimumab-Induced Disseminated Superficial Porokeratosis; Nephrotic Syndrome Associated with Adalimumab; Methotrexate-Induced Periorbital Radiation Recall; Micturition Difficulty Associated with Aripiprazole; Aripiprazole-Related Acute Transient Myopia and Diplopia; Intestinal Necrosis Associated with Calcium Polystyrene Sulfonate
Authors: Shuster Joel
Published: May 2011

The purpose of this feature is to heighten awareness of specific adverse drug reactions (ADRs), discuss methods of prevention, and promote reporting of ADRs to the US Food and Drug Administration's (FDA's) MedWatch program (800-FDA-1088). If you have reported an interesting, preventable ADR to MedWatch, please consider sharing the account with our readers.
Vancomycin (Rectal): Clostridium difficile Infection (Severe/Complicated)
Authors: Generali Joyce A. , Cada Dennis J.
Published: May 2011

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .
A Retrospective Analysis of Risk Factors and Therapeutic Outcomes for Clostridium difficile Infection
Authors: Netland Patrick J. , Brochardt Stephanie M. , Koo Ji M. , Lo Tze Shien , Krenz Tammy
Published: May 2011

Purpose

To determine the Clostridium difficile infection (CDI) recurrence rate at the Veterans Affairs Medical Center (VAMC) in Fargo, North Dakota, and to determine whether certain variables (eg, type of antibiotic, medication, chronic disease state, CDI symptom control) were predictive of CDI recurrence.

Methods

Demographic information and laboratory data from 174 adult outpatients and inpatients were collected from electronic medical records between January 1997 and September 2009. In addition, information about the duration of non-CDI antibiotic therapy and the use of proton pump inhibitors, histamine H2 blockers, corticosteroids, and immunosuppressive medications within 60 days of CDI was collected. Information regarding comorbid conditions (eg, cancer, liver or renal disease, diabetes, chronic heart failure) in patients at the time of CDI was also collected.

Results

Patients below the median age of 69.5 years were more likely to continue to have diarrhea after CDI treatment than patients who were older than the median age (relative risk 1.86; 95% CI, 1.06-3.26). No association was observed between previous non-CDI treatment antibiotic use, other medication use, or comorbid conditions and the recurrence of CDI.

Conclusion

CDI recurrence rate at VAMC was 14%. No statistically significant association could be made between recurrence of CDI and antibiotic or medication used within 60 days of infection or with chronic disease states at the time of CDI infection. Patients younger than 69.5 years were more likely to continue to have diarrhea after CDI treatment.
Impact and Determinants of Commercial Computerized Prescriber Order Entry on the Medication Administration Process
Authors: Abbass Ibrahim , Mhatre Shivani , Sansgiry Sujit S. , Tipton Joyce , Frost Craig
Published: May 2011

Purpose

The purpose of this study was to evaluate the impact of commercial computerized prescriber order entry (CPOE) on efficiency outcomes in an 864-bed community hospital.

Methods

A retrospective study was developed to measure medication errors and medication order turnaround time in St. Luke's Episcopal Hospital located in the Texas Medical Center. The study data were collected by stratified random sampling through a review of medication orders submitted to the pharmacy using a paper-based order system and the CPOE system. Descriptive frequencies, chi-square test, Wilcoxon matched-pairs sign rank test, and logistic regression and multiple regression analyses were conducted to examine the relationship among variables.

Results

Of the 1,110 total orders reviewed (563 paper-based and 547 CPOE), a total of 135 medication errors were found, with 10.5% in paper-based versus 1.6% in CPOE. The most prevalent errors in paper-based orders were inappropriate abbreviations (24.4%), incorrect doses (15.6%), occurrences of allergy (13.3%), and wrong administration frequency (9.6%). In CPOE orders, the errors were occurrences of allergy (10.4%), incorrect doses (2.2%), and drug interaction (0.7%). CPOE resulted in a 50% reduction of medication order turnaround time (median = 24 minutes CPOE vs 48 minutes paper orders). A potential medication error, unidentified prescribers within medication orders, urgency of medication order, and implementation of CPOE were the significant ( P < .05) determinants of medication order turnaround time.

Conclusion

The implementation of a commercial CPOE system reduced medication errors and improved medication order turnaround times.
Ceftaroline Fosamil
Authors: Cada Dennis J. , Levien Terri L. , Baker Danial E.
Published: May 2011

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. Subscribers to The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X.

Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The May 2011 monograph topics are on roflumilast, belimumab, azilsartan medoxomil, factor XIII concentrate (human), and crizotinib. The DUE/MUE is on roflumilast.
E-Prescribing Update and Implications for Hospital Pharmacy
Authors: Fox Brent I. , Felkey Bill G.
Published: May 2011

Numerous efforts are underway to enable the sharing of clinical information among providers. E-prescribing is actually one of the more mature examples of the sharing of structured data found in today's health care system. In this installment, we provide an update on e-prescribing. We also use the example of a major player in e-prescribing to illustrate the potential of a communication network among providers.
Recent Publications on Medications and Pharmacy
Authors: Russett Flint
Published: May 2011

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.
Microstructural Characterization of an AISI D2 Tool Steel Submitted to Cryogenic Treatment
Authors: Farina Paula Fernanda da Silva , Barbosa Celso Antonio , Goldenstein Hélio
Published: May 2011

Recent literature has shown several papers dealing with cryogenic treatments of tool steels. Most of them see an improvement in wear resistance supposedly due to microstructural modifications that occur at cryogenic temperatures. Cryogenic treatments are supposed to modify the way secondary carbides precipitate, obtaining a finer and more homogeneous distribution. Specimens of an AISI D2 tool steel were submitted to different thermal cycles, including cryogenic treatment, and the volumetric fraction of micrometric carbides was determined. The samples were analyzed by scanning electron microscopy and the image analysis was carried out with Image J software. The present work also discusses what is understood about secondary carbides and the modifications that occur with micrometric (from the austenite-carbide field) and nanometric (from the temper of martensite) secondary carbides. No difference was found between the micrometric carbide with and without cryogenic treatment, while some indications were found that the nanometric carbides are refined and more homogeneously distributed after cryogenic treatment.
Electrochemical studies of U(VI)/U(V) in saturated Na2CO3solution at gold nanoparticles embedded CTA-modified electrode
Authors: Sharma Manoj K. , Ambolikar Arvind S. , Aggarwal Suresh K.
Published: May 2011

Gold nanoparticles (AuNPs) were prepared in the matrix of cellulose triacetate (CTA) membrane containing a liquid anion exchanger trioctylmethylammonium chloride (Aliquat-336). The AuCl4−ions were transferred in the membrane matrix by anion-exchange process, and then subsequently reduced with NaBH4to form AuNPs in the membrane. The AuNPs-embedded CTA (AuNPs-CTA) membrane was characterized by UV-visible spectroscopy, XRD and AFM. The electrochemical properties of AuNPs-CTA modified electrode were evaluated by studying redox behavior of UO22+/UO2+couple in saturated Na2CO3solution, using voltammetric techniques. In carbonate solution, the predominant species of UO22+is [UO2(CO3)3]4−, and a stable UO2(CO3)35−complex is formed by one-electron reduction of UO2(CO3)34−. Previous reports show that the UO22+/UO2+couple, which is electrochemically reversible in less complexing media, becomes electrochemically irreversible in aqueous CO32−solution. In this study, an electrocatalytic reduction of UO22+to UO2+in saturated Na2CO3solution was observed at AuNPs-CTA-modified electrode with higher current density and faster heterogeneous electron-transfer kinetics than that at bare Au electrode. The standard heterogeneous rate constant,kº, for the reduction process at AuNPs-CTA modified electrode was about 25 times higher than that of bare Au electrode. Therefore, it is concluded that AuNPs-CTA membrane has improved the interfacial electron-transfer properties of electrode, resulting in a better electrochemical response than bare Au electrode.
“I have tried to capture you …”: Rethinking the “Alma” Theme from Mahler's Sixth Symphony
Authors: Monahan Seth
Published: May 2011

Since the 1940s, Mahler's Sixth Symphony has been transmitted with an informal “domestic” program centered on several claims first made in Alma Mahler's Erinnerungen. In the work, she writes, Gustav meant to depict their children (in the Scherzo), himself (in the Finale), and finally her, in the first movement's swooning secondary theme. Though critics have almost universally accepted Alma's anecdote, few have seriously asked the important question of what such a portrait would be doing in Mahler's most expressly tragic symphony. In this study I offer a hermeneutic perspective on the Sixth that concedes the possible truth of Alma's anecdote but which challenges the conventional assumption that such a spousal tribute should best be understood as a one-sided testament to Mahler's newfound nuptial bliss. After examining the theme's reception history and Mahler's domestic circumstances during the symphony's composition, I explore the ways in which the first movement's sonata narrative—a protracted conflict between (and reconciliation of) its two gendered subjects—suggestively mirrors the prevailing psychodynamics of Mahler's strained marriage. At the end of the essay I propose how this revised hearing of the opening movement might prompt a reimagining of the entire Sixth as a projected or imagined “domestic tragedy,” with special focus on the intertextual links between the work's outer movements and also between the cataclysmic finale and the penitentially anguished portions of the Third Symphony's “Armer Kinder Betterlied.”
Goal-Directed Soul? Analyzing Rhythmic Teleology in African American Popular Music
Authors: Fink Robert
Published: May 2011

A theoretical consideration of teleology in African American popular music, focusing on the late-1960s output of Motown Records. The question of goal direction and musical value in popular music is traced back to the theoretical dispute between Leonard Meyer and Charles Keil, who stand in for the two poles of an outmoded binarism: a “classical” music defined by control of teleology and delayed gratification, and a “popular” music defined by a liberating feeling of groove in an endless present. Soul music and culture, steeped in the aspirational drive of the black middle class, falsifies this view of African American popular music. Drawing on more recent analytical work on grooves (Butler, Danielsen), a model of rhythmic teleology is developed and then tested on two seminal tracks produced by Norman Whitfield and sung by the Temptations. In both “Cloud Nine” (1968) and “Runaway Child, Running Wild” (1969), Motown's signature “four on the floor beat” functions as a rhythmic tonic. Reception study supports the proposition that Whitfield's control of rhythmic teleology, combined with socially conscious lyrics about drug use and the counterculture, represent a powerful intervention in favor of goal direction and delayed gratification at a pivotal moment for the African American middle class.
Inferring Epidemiological Parameters on the Basis of Allele Frequencies
Authors: Stadler Tanja
Published: May 2011

In this article, I develop a methodology for inferring the transmission rate and reproductive value of an epidemic on the basis of genotype data from a sample of infected hosts. The epidemic is modeled by a birth–death process describing the transmission dynamics in combination with an infinite-allele model describing the evolution of alleles. I provide a recursive formulation for the probability of the allele frequencies in a sample of hosts and a Bayesian framework for estimating transmission rates and reproductive values on the basis of observed allele frequencies. Using the Bayesian method, I reanalyze tuberculosis data from the United States. I estimate a net transmission rate of 0.19/year [0.13, 0.24] and a reproductive value of 1.02 [1.01, 1.04]. I demonstrate that the allele frequency probability under the birth–death model does not follow the well-known Ewens’ sampling formula that holds under Kingman's coalescent.
Genetic Variation and the Fate of Beneficial Mutations in Asexual Populations
Authors: Lang Gregory I , Botstein David , Desai Michael M
Published: May 2011

The fate of a newly arising beneficial mutation depends on many factors, such as the population size and the availability and fitness effects of other mutations that accumulate in the population. It has proved difficult to understand how these factors influence the trajectories of particular mutations, since experiments have primarily focused on characterizing successful clones emerging from a small number of evolving populations. Here, we present the results of a massively parallel experiment designed to measure the full spectrum of possible fates of new beneficial mutations in hundreds of experimental yeast populations, whether these mutations are ultimately successful or not. Using strains in which a particular class of beneficial mutation is detectable by fluorescence, we followed the trajectories of these beneficial mutations across 592 independent populations for 1000 generations. We find that the fitness advantage provided by individual mutations plays a surprisingly small role. Rather, underlying “background” genetic variation is quickly generated in our initially clonal populations and plays a crucial role in determining the fate of each individual beneficial mutation in the evolving population.
A Region of the Nucleosome Required for Multiple Types of Transcriptional Silencing in Saccharomyces cerevisiae
Authors: Prescott Eugenia T , Safi Alexias , Rusche Laura N
Published: May 2011

Extended heterochromatin domains, which are repressive to transcription and help define centromeres and telomeres, are formed through specific interactions between silencing proteins and nucleosomes. This study reveals that in Saccharomyces cerevisiae, the same nucleosomal surface is critical for the formation of multiple types of heterochromatin, but not for local repression mediated by a related transcriptional repressor. Thus, this region of the nucleosome may be generally important to long-range silencing. In S. cerevisiae, the Sir proteins perform long-range silencing, whereas the Sum1 complex acts locally to repress specific genes. A mutant form of Sum1p, Sum1-1p, achieves silencing in the absence of Sir proteins. A genetic screen identified mutations in histones H3 and H4 that disrupt Sum1-1 silencing and fall in regions of the nucleosome previously known to disrupt Sir silencing and rDNA silencing. In contrast, no mutations were identified that disrupt wild-type Sum1 repression. Mutations that disrupt silencing fall in two regions of the nucleosome, the tip of the H3 tail and a surface of the nucleosomal core (LRS domain) and the adjacent base of the H4 tail. The LRS/H4 tail region interacts with the Sir3p bromo-adjacent homology (BAH) domain to facilitate Sir silencing. By analogy, this study is consistent with the LRS/H4 tail region interacting with Orc1p, a paralog of Sir3p, to facilitate Sum1-1 silencing. Thus, the LRS/H4 tail region of the nucleosome may be relatively accessible and facilitate interactions between silencing proteins and nucleosomes to stabilize long-range silencing.
Trex2 Enables Spontaneous Sister Chromatid Exchanges Without Facilitating DNA Double-Strand Break Repair
Authors: Dumitrache Lavinia C , Hu Lingchuan , Son Mi Young , Li Han , Wesevich Austin , Scully Ralph , Stark Jeremy , Hasty Paul
Published: May 2011

Trex2 is a 3′ → 5′ exonuclease that removes 3′-mismatched sequences in a biochemical assay; however, its biological function remains unclear. To address biology we previously generated trex2null mouse embryonic stem (ES) cells and expressed in these cells wild-type human TREX2 cDNA (Trex2hTX2) or cDNA with a single-amino-acid change in the catalytic domain (Trex2H188A) or in the DNA-binding domain (Trex2R167A). We found the trex2null and Trex2H188A cells exhibited spontaneous broken chromosomes and trex2null cells exhibited spontaneous chromosomal rearrangements. We also found ectopically expressed human TREX2 was active at the 3′ ends of I-SceI–induced chromosomal double-strand breaks (DSBs). Therefore, we hypothesized Trex2 participates in DNA DSB repair by modifying 3′ ends. This may be especially important for ends with damaged nucleotides. Here we present data that are unexpected and prompt a new model. We found Trex2-altered cells (null, H188A, and R167A) were not hypersensitive to camptothecin, a type-1 topoisomerase inhibitor that induces DSBs at replication forks. In addition, Trex2-altered cells were not hypersensitive to γ-radiation, an agent that causes DSBs throughout the cell cycle. This observation held true even in cells compromised for one of the two major DSB repair pathways: homology-directed repair (HDR) or nonhomologous end joining (NHEJ). Trex2 deletion also enhanced repair of an I-SceI–induced DSB by both HDR and NHEJ without affecting pathway choice. Interestingly, however, trex2null cells exhibited reduced spontaneous sister chromatid exchanges (SCEs) but this was not due to a defect in HDR-mediated crossing over. Therefore, reduced spontaneous SCE could be a manifestation of the same defect that caused spontaneous broken chromosomes and spontaneous chromosomal rearrangements. These unexpected data suggest Trex2 does not enable DSB repair and prompt a new model that posits Trex2 suppresses the formation of broken chromosomes.
Halliday’s model of register revisited and explored
Authors: Lukin Annabelle , Moore Alison , Herke Maria , Wegener Rebekah , Wu Canzhong
Published: May 2011

Halliday’s description of register as ‘a variety of language, corresponding to a variety of situation’, with situation interpreted ‘by means of a conceptual framework using the terms “field”, “tenor” and “mode”’ (Halliday, 1985/89: 29, 38) is revisited to reflect on the theoretical work the term ‘register’ does within the SFL paradigm. In doing so, we recognise that the concepts of a linguistic theory are ‘ineffable’ (Halliday 2002[1988]); i.e. that ‘providing definitions of a theoretical term... requires that it be positioned vis-à-vis other concepts in the theory’ (Hasan, 2004: 16). It follows that changing the position of ‘register’ in the theory changes the nature of the concept. So while alternative uses of the term ‘register’ – such as in Martin’s genre model (e.g. 1992) and Halliday’s model – may advance a shared program for language description and explanation as a route to social change, they must be seen as more than terminological variants. One consequence of the productivity of Martin’s approach has been that the Hallidayan line of register theory has not had sufficient critical explication. This paper therefore begins with a brief review of the register concept. It then exemplifies the term, as postulated by Halliday, with a registerial analysis of surgical interaction, drawing on Hasan’s context modelling (e.g. Hasan 1995, 2004, 2009a), and adopting what Matthiessen (1993) calls a ‘metafunctional slice’ with ‘multistratal coverage’. By accounting for choice at different strata, we seek to ‘relate wording to context via meaning which acts as the interface between the two’ (Hasan 2009a: 182).
Flow modeling and analysis of compound channel in river network with complex floodplains and groynes
Authors: Ahmed Hassan , Tanaka Norio , Tamai Nobuyuki
Published: May 2011

Presented here are flow simulations of a network of natural rivers flanked by one or two large and complex floodplains with impermeable groynes and bridge embankments using one- and quasi-two-dimensional dynamic flow models. The effects of the large floodplain storage capacity, momentum transfer interaction and apparent shear stress at the vertical interface between the main channel and floodplain on the flow-simulated discharge and water depth values could be well explained. The two models were tested and validated in the Arakawa River basin, Kanto Region, Japan. The simulated results show that the large floodplain storage capacity greatly affected the flow discharge and water depth results and cannot be neglected. The quasi-two-dimensional river flow model was used in a flow simulation of a compound channel with complex floodplains with groynes and gave more acceptable results. In the simulated case, the average reduction in flood discharge using floodplain groynes was about 7–15%. Thus, floodplain groynes can be effective for flood protection and attenuation.
Comparing the capability of distributed and lumped hydrologic models for analyzing the effects of land use change
Authors: Paudel Murari , Nelson E. James , Downer Charles W. , Hotchkiss Rollin
Published: May 2011

Empirically based lumped hydrologic models have an extensive track record of use for various engineering applications. Physically based, multi-dimensional distributed models have also been in development and use for many years. Despite the availability of high resolution data, better computational resources and robust, numerical methods implemented in such models, their usage is still limited, especially in the realm of surface water runoff simulation. Lumped models are often extended to solve complex hydrologic problems that may be beyond their capabilities. Here we attempt to differentiate the ability of lumped and distributed models to analyze a common watershed development issue such as land use change. For this, we employ two common US Army Corps of Engineers (USACE) models, well established in the literature and application, using the Hydrologic Engineering Center – Hydrologic Modeling System (HEC-HMS) model in a fully lumped mode and the fully distributed model Gridded Surface Subsurface Hydrologic Analysis (GSSHA). A synthetic watershed is used to establish that a distributed model like GSSHA more intuitively simulates land use change scenarios by distinguishing the spatial location of the change and its effects on the watershed response. An actual watershed at Tifton, Georgia is used to validate the observations made from the synthetic watershed.
Logistic regression analysis to estimate contaminant sources in water distribution systems
Authors: Liu Li , Sankarasubramanian A. , Ranjithan S. Ranji
Published: May 2011

Accidental or intentional contamination in a water distribution system (WDS) has recently attracted attention due to the potential hazard to public health and the complexity of the contaminant characteristics. The accurate and rapid characterization of contaminant sources is necessary to successfully mitigate the threat in the event of contamination. The uncertainty surrounding the contaminants, sensor measurements and water consumption underscores the importance of a probabilistic description of possible contaminant sources. This paper proposes a rapid estimation methodology based on logistic regression (LR) analysis to estimate the likelihood of any given node as a potential source of contamination. Not only does this algorithm yield location-specific probability information, but it can also serve as a prescreening step for simulation–optimization methods by reducing the decision space and thus alleviating the computational burden. The applications of this approach to two example water networks show that it can efficiently rule out numerous nodes that do not yield contaminant concentrations to match the observations. This elimination process narrows down the search space of the potential contamination locations. The results also indicate that the proposed method efficiently yields a good estimation even when some noise is incorporated into the measurements and demand values at the consumption nodes.
A new wavelet–bootstrap–ANN hybrid model for daily discharge forecasting
Authors: Tiwari Mukesh K. , Chatterjee Chandranath
Published: May 2011

A new hybrid model, the wavelet–bootstrap–ANN (WBANN), for daily discharge forecasting is proposed in this study. The study explores the potential of wavelet and bootstrapping techniques to develop an accurate and reliable ANN model. The performance of the WBANN model is also compared with three more models: traditional ANN, wavelet-based ANN (WANN) and bootstrap-based ANN (BANN). Input vectors are decomposed into discrete wavelet components (DWCs) using discrete wavelet transformation (DWT) and then appropriate DWCs sub-series are used as inputs to the ANN model to develop the WANN model. The BANN model is an ensemble of several ANNs built using bootstrap resamples of raw datasets, whereas the WBANN model is an ensemble of several ANNs built using bootstrap resamples of DWCs instead of raw datasets. The results showed that the hybrid models WBANN and WANN produced significantly better results than the traditional ANN and BANN, whereas the BANN model is found to be more reliable and consistent. The WBANN and WANN models simulated the peak discharges better than the ANN and BANN models, whereas the overall performance of WBANN, which uses the capabilities of both bootstrap and wavelet techniques, is found to be more accurate and reliable than the remaining three models.
Application of genetic programming to modeling pipe failures in water distribution systems
Authors: Xu Qiang , Chen Qiuwen , Li Weifeng
Published: May 2011

The water loss from a water distribution system is a serious problem for many cities, which incurs enormous economic and social loss. However, the economic and human resource costs to exactly locate the leakage are extraordinarily high. Thus, reliable and robust pipe failure models are demanded to assess a pipe's propensity to fail. Beijing City was selected as the case study area and the pipe failure data for 19 years (1987–2005) were analyzed. Three different kinds of methods were applied to build pipe failure models. First, a statistical model was built, which discovered that the ages of leakage pipes followed the Weibull distribution. Then, two other models were developed using genetic programming (GP) with different data pre-processing strategies. The three models were compared thereafter and the best model was applied to assess the criticality of all the pipe segments of the entire water supply network in Beijing City based on GIS data.
Mathematical modelling of a hydraulic controller for PRV flow modulation
Authors: AbdelMeguid Hossam , Skworcow Piotr , Ulanicki Bogumil
Published: May 2011

This paper describes the development of mathematical models, which represent static and dynamic properties of the AQUAI-MOD® hydraulic controller coupled with a standard pressure reducing valve (PRV) as well as a new experimental set-up for testing the controller and calibrating and validating the models. The purpose of the AQUAI-MOD® controller is to modulate the PRV outlet pressure according to the valve flow. The controller has been experimentally tested to assess its operation in different conditions and operating ranges and in all cases showed good performance. The mathematical models of the PRV and its controller have been developed and solved using the Mathematica software package to represent both steady state and dynamics conditions. The numerical results of simulation of the mathematical model have been compared with experimental data and showed a good agreement in magnitude and trends. The model can be used to simulate the behaviour of the PRV and the AQUAI-MOD® hydraulic controller in typical network applications. It can also be used at the design stage to size the controller components and to compute the required set points for the minimum and the maximum pressure before installing the controller in the field.
Economics in Crisis
Authors: DeLong J. Bradford
Published: May 2011

Have economists forgotten what they once knew about financial markets, macroeconomics and their interactions? Brad DeLong of UC Berkeley certainly thinks so and interprets Larry Summers as saying the same.
The Future Nephrology Workforce
Authors: Parker Mark G. , Ibrahim Tod , Shaffer Rachel , Rosner Mitchell H. , Molitoris Bruce A.
Published: May 2011

Interest in nephrology as a career is declining and has been on the decline for nearly one decade. From 2002 to 2009, all internal medicine subspecialties except geriatric medicine increased the number of available fellowship positions. However, only two subspecialties attracted fewer United States medical graduates (USMGs) in 2009 than in 2002: geriatric medicine and nephrology. This drop occurred at a time when demand for nephrologists is increasing and when the specialty is having a harder time benefiting from the substantial contribution of international medical graduates (IMGs).

Today's USMGs possess fundamentally different career and personal goals from their teachers and mentors. Medical students report receiving minimal exposure to nephrology in clinical rotations, and they perceive that the specialty is too complex, uninteresting, and lacks professional opportunity.

Meanwhile, the demographics of kidney disease in the United States, as well as recent national health policy developments, indicate a growing need for nephrologists. Efforts to improve the educational continuum in nephrology and enhance mentorship are essential to restoring interest in nephrology for USMGs, maintaining its appeal among IMGs, and developing a workforce sufficient to meet future demand for renal care.
Long-Term Effects of Kidney Donation on Renal Function and Blood Pressure in African Americans
Authors: Budisavljevic Milos N. , Nietert Paul J. , Zhai Yusheng , Dooley Mary J. , Rajagopalan P.R.
Published: May 2011

Background and objectives

African Americans (AAs) have four times higher prevalence of ESRD than Caucasians. Therefore, long-term effects of kidney donation are of considerable importance in this patient population.

Design, setting, participants, & measurements

GFR was measured by 125I-iothalamate clearance, 24-hour urine albumin excretion, and 24-hour BP monitoring in 33 AAs and 11 CAs who donated kidneys for transplantation 5 to 23 years previously.

Results

Mean GFRs were 76 ± 13 and 78 ± 11 ml/min per 1.73 m2 for AA and CA donors, respectively. Nine percent of the AA donors and none of the CA donors had GFRs below 60 ml/min per 1.73 m2. AA donors had a tendency for lower prevalence of microalbuminuria compared with CA donors (18.1% versus 36.3%) and a tendency for higher prevalence of macroalbuminuria compared with CAs (12.1% versus 0.0%). Twenty-four percent of the AAs, and 45% of the CAs were hypertensive with mean daytime BP ≥135/85 mmHg. Only 6% of AAs had a decrease in mean nocturnal systolic BP of 10% or more as compared with daytime readings. Older age at time of donation was associated (P = 0.046) with lower GFR values compared with younger ages.

Conclusion

Carefully selected AA kidney donors have well preserved renal function and a low prevalence of hypertension many years after kidney donation. Abnormal albumin excretion and loss of physiologic decrease in nocturnal BP is more prevalent in AA donors than the general AA population. Older age at donation may predict lower GFR after donation.
Inflammatory Markers and Risk of Cerebrovascular Events in Patients Initiating Dialysis
Authors: Sozio Stephen M. , Coresh Josef , Jaar Bernard G. , Fink Nancy E. , Plantinga Laura C. , Armstrong Paige A. , Longenecker J. Craig , Sharrett A. Richey , Powe Neil R. , Parekh Rulan S.
Published: May 2011

Background and objectives

Stroke remains a leading cause of morbidity and mortality for patients on dialysis; however, its risk factors in this population and measures to prevent it are not well understood.

Design, setting, participants, & measurements

We investigated whether inflammation was associated with cerebrovascular events in a national US cohort of 1041 incident dialysis patients enrolled from October 1995 to June 1998 and followed until January 31, 2004. Incident cerebrovascular events were defined as nonfatal (hospitalized stroke, carotid endarterectomy) and fatal (stroke death) events after dialysis initiation. With Cox proportional hazards regression analysis accounting for the competing risk of nonstroke death, we assessed the independent event risk associated with baseline levels of multiple inflammatory markers (high-sensitivity C-reactive protein [hsCRP], interleukin-6 (IL-6), matrix metalloproteinase-3 [MMP-3], and P-selectin) and hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor (statin) use, which may have pleiotropic inflammatory effects.

Results

165 patients experienced a cerebrovascular event during 3548 person-years of follow-up; overall incidence rate was 4.9/100 person-years. None of the inflammatory markers were associated with cerebrovascular event risk (adjusted hazard ratios [HRs] per log unit [95% confidence interval]: hsCRP, 0.97 [0.85 to 1.11]; IL-6, 1.04 [0.85 to 1.26]; MMP-3, 1.02 [0.70 to 1.48]; P-selectin, 0.98 [0.57 to 1.68]). Statin use was also not associated with significant risk of events in unadjusted (HR 1.07 [0.69 to 1.68]) or propensity-score adjusted analyses (HR 0.98 [0.61 to 1.56]).

Conclusions

In conclusion, neither inflammatory markers nor statin use was associated with risk of cerebrovascular events. Further studies are needed to understand the pathophysiology and prevention of stroke in patients on dialysis.
In vitro evaluation of self-etch bonding in orthodontics using cyclic fatigue
Authors: Mansour Ameerah Yousef , Drummond James L. , Evans Carla A. , Bakhsh Zuhair
Published: May 2011

Objective:

To evaluate the bond strength of a self-etch bonding system using static loading and cyclic fatigue with shear testing. This is a two-part evaluation; the first part will evaluate shear testing, the second part tensile testing.

Materials and Methods:

Bovine teeth (n  =  82) were randomly distributed to either a self-etch (Transbond Plus) or total-etch (37% phosphoric-acid + Transbond XT) group. The static shear (SSBS) and cyclic shear (CSBS) bond strengths were measured 24 hours after the bonding of mesh-based brackets. The adhesive remnant index (ARI) and failure sites were evaluated.

Results:

The mean SSBS was 34.25 ± 9.21 and 24.64 ± 9.42 MPa for the total- and self-etch groups, respectively. CSBS was 24.07 ± 0.65 MPa and 18.92 ± 1.08 MPa for the total- and self-etch groups, respectively. Cyclic loading produced lower bond strengths compared to static testing for both adhesives; the difference was only statistically significant for the total-etch system. Comparison of the two materials showed a statistically significant difference between the two techniques. The total-etch had higher bond strengths than the self-etch bonding system. The samples showed a predominance of ARI scored of 2 and 1, and their bonding failure sites were cohesive within the composite.

Conclusion:

Cyclic loading, simulating occlusal forces, reduces the bond strength of both bonding systems. Even though the self-etch bonding system had lower shear bond strength than the total-etch system, both were still clinically acceptable.
Automatic real-time guidance of laser machining with inline coherent imaging
Authors: Webster Paul J. L. , Wright Logan G. , Mortimer Kevin D. , Leung Ben Y. , Yu Joe X. Z. , Fraser James M.
Published: May 2011

Optical coherence imaging can measure hole depth in real-time (>20 kHz) during laser drilling without being blinded by intense machining light or incoherent plasma emissions. Rapid measurement of etch rate and stochastic melt relaxation makes these images useful for process development and quality control in a variety of materials including metals, semiconductors, and dielectrics. The ability to image through the ablation crater in materials transparent to imaging light allows the guidance of blind hole cutting even with limited a priori knowledge of the sample. Significant improvement in hole depth accuracy with the application of manual feedback from this imaging has been previously demonstrated [P. J. L. Webster et al., Opt. Lett. 35, 646 (2010)]. However, the large quantity of raw data and computing overhead are obstacles for the application of coherent imaging as a truly automatic feedback mechanism. Additionally, the high performance components of coherent imaging systems designed for their traditional application in biological imaging are costly and may be unnecessary for materials processing. In this work, we present a coherent imaging system design that costs less than a fifth of comparable commercial products. We also demonstrate streamlined image processing suited for automated feedback that increases processing speed by two orders of magnitude.
Comprehensive predictive modeling and parametric analysis of multitrack direct laser deposition processes
Authors: Wen Shaoyi , Shin Yung C.
Published: May 2011

Direct laser deposition is a very useful method of fabricating complex parts directly from CAD drawings. Despite its usefulness, many parameters that affect the final quality of the fabricated part make the selection of optimal operating conditions difficult. In this paper, new comprehensive numerical modeling is presented to describe the underlying physics in multitrack direct laser deposition processes including laser powder interaction, mass addition, fluid motion, melting, and solidification. The model rigorously considers the continuous mass addition effects in the set of governing equations. An improved level-set equation is adopted for complex evolution of interfaces for multitrack deposition. Distinct thermal-fluidic behavior and complex three-dimensional part geometry are revealed by accurately modeling the molten pool shape, liquid melt flow, heat affected zone and final deposition track height and width during multitrack direct laser deposition. In addition, an experimental parametric study on various operating parameters on the final quality is presented. The model presented in the paper can be used to design graded or/and desired material structures and properties for multitrack laser deposition processes.
Experimental investigation of laser shock peening using femtosecond laser pulses
Authors: Lee Dongkyun , Kannatey-Asibu Elijah
Published: May 2011

In this study, the feasibility of laser shock peening using ultrafast laser pulses was experimentally investigated. A top coating of zinc with a water confining layer was applied in the investigation. The zinc coating was used for the thermoprotective effect. A high numerical aperture (NA≈0.5) aspheric lens was used to minimize the optical breakdown of water. Microhardness measurements were made on the top surface of the shock peened specimen and compared with the original material hardness. The results provide useful insight on conditions that are necessary to achieve desirable results.
Recent advances in laser surface treatment of titanium alloys
Authors: Candel J. J. , Amigó V.
Published: May 2011

This paper reviews progress over the last five years in the field of laser surface modification of titanium alloys. The authors analyze the effect of new laser technologies and new materials as tools for improving surface properties—specifically, biocompatibility and resistance to wear, corrosion, and high temperatures. The authors discuss the effect of laser processing parameters on the microstructure and compare the results obtained by various researchers. Therefore, an overview of the difficulties involved in the laser processing of titanium is provided with a discussion of future prospects.
Mobile phones and sleep - A review
Authors: Supe Sanjay
Published: May 2011

Mobile phones and sleep - A review

The increasing use of mobile phones has raised concerns regarding the potential health effects of exposure to the radiofrequency electromagnetic fields. An increasing amount research related to mobile phone use has focussed on the possible effects of mobile phone exposure on human brain activity and function. In particular, the use of sleep research has become a more widely used technique for assessing the possible effects of mobile phones on human health and wellbeing especially in the investigation of potential changes in sleep architecture resulting from mobile phone use. Acute exposure to a mobile phone prior to sleep significantly enhances electroencephalogram spectral power in the sleep spindle frequency range. This mobile phone-induced enhancement in spectral power is largely transitory and does not linger throughout the night. Furthermore, a reduction in rapid eye movement sleep latency following mobile phone exposure was also found, although interestingly, neither this change in rapid eye movement sleep latency or the enhancement in spectral power following mobile phone exposure, led to changes in the overall quality of sleep. In conclusion, a short exposure to the radiofrequency electromagnetic fields emitted by a mobile phone handset immediately prior to sleep is sufficient to induce changes in brain activity in the initial part of sleep. The consequences or functional significance of this effect are currently unknown and it would be premature to draw conclusions about possible health consequences.
Position of effective electron source for shielded electron beams from a therapeutic linear accelerator
Authors: Al Asmary Mohammed , Ravikumar Manickam
Published: May 2011

Position of effective electron source for shielded electron beams from a therapeutic linear accelerator

The effective electron source positions for the standard electron cones and for the shielded field sizes with cerrobend inserts were measured based on Inverse Square Law (ISL) and the Inverse Slope (IS) method for various electron energies.

The charge measurements were carried out using a 0.6 cc ion chamber (PTW, Type 30001) connected to a PTW Unidos E digital electrometer in a polystyrene phantom for electron beam energies of 6-18 MeV. The resultant charge for 100 MU setting was measured at nominal source to surface distances (SSDs) of 100-120 cm for cone and cerrobend defined field sizes.

The effective SSD (SSDeff) was found to be different for the same field size defined by electron applicator and the cerrobend shield placed in 25×25 cm standard cone. Strong dependency of SSDeff with field size and electron beam energy was noticed.

The results from the ISL and IS method are consistent, hence either of the two methods can be used to determine the effective source position. Whenever treatment is to be given with shielded electron portal, the SSDeff for that field needs to be determined. Same SSDeff as that of the standard cone can be used for minimum shielded electron portals.
Treatment planning system and dose delivery accuracy in extracranial stereotactic radiotherapy using Elekta body frame
Authors: Dawod Tamer , Bremer Michael , Karstens Johann , Werner Martin
Published: May 2011

Treatment planning system and dose delivery accuracy in extracranial stereotactic radiotherapy using Elekta body frame

The purpose of this study was to measure the photon beam transmission through the Elekta Stereotactic Body Frame (ESBF) and treatment couch, to determine the dose calculations accuracy of the MasterPlan Treatment Planning System (TPS) using Pencil Beam (PBA) and Collapsed Cone (CCA) algorithms during the use of Elekta Stereotactic Body Frame (ESBF), and to demonstrate a simple calculation method to put this transmission into account during the treatment planning dose calculations.

The dose was measured at the center of an in-house custom-built inhomogeneous PMMA thorax phantom with and without ‘the frame + treatment couch’. The phantom was CT-imaged inside the ESBF and planned with multiple 3D-CRT fields using PBA and CCA for photon beams of energies 6 MV and 10 MV. There were two treatment plans for dose calculations. In the first plan, the ‘frame + couch’ were included in the body contour and, therefore, included in the TPS dose calculations. In the second plan, the ‘frame + couch’ were not included in the body contour and, therefore, not included in the calculations. Transmission of the ‘frame + couch’ was determined by the ratio of the dose measurements with the ‘frame + couch’ to the measurements without them. To validate the accuracy of the calculation model, plans with and without the ‘frame + couch’ surrounding the phantoms were compared with their corresponding measurements.

The transmission of the ‘frame + couch’ varies from 90.23-97.54% depending on the energy, field size, the angle of the beams and whether the beams also intercept them. The validation accuracy of the Pencil Beam (PBA) and Collapsed Cone (CCA) algorithms were within 5.33% and 4.04% respectively for the individual measurements for all gantry angles under this study. The results showed that both PBA and CCA algorithms can calculate the dose to the target within 4.25% and 1.95% of the average measured value.

The attenuation caused by the ESBF and couch must be accounted into the planning process. For MasterPlan, the ‘frame + couch’ should be contoured and included in all calculations. This can be done easily and accurately.
Improvement of the quality of effective dose estimation by interlaboratory comparisons
Authors: Katarzyna Ciszewska , Malgorzata Dymecka , Tomasz Pliszczynski , Jakub Osko
Published: May 2011

Improvement of the quality of effective dose estimation by interlaboratory comparisons

Radiation Protection Measurements Laboratory (RPLM) of the Institute of Atomic Energy POLATOM determines radionuclides in human urine to estimate the effective dose. Being an accredited laboratory, RPLM participated in interlaboratory comparisons in order to assure the quality of services concerning monitoring of internal contamination. The purpose of the study was to examine the effect of interlaboratory comparisons on the accuracy of the provided measurements. The results regarding tritium (3H) and strontium (90Sr) determination, obtained within the radiotoxicological intercomparison exercises, organized by PROCORAD, in 2005-2010, were analyzed and the methods used by the laboratory were verified and improved.