bluuebunny/crossref_metadata_2025 huggingface dataset:
Pore‐Water Pressures Associated with Clogging of Soil Pipes: Numerical Analysis of Laboratory Experiments
Authors: Wilson G. V. , Fox G. A.
Published: May 2013

Clogging of soil pipes due to excessive internal erosion has been hypothesized to cause extreme erosion events such as landslides, debris flows, and gullies, but confirmation of this phenomenon has been lacking. Laboratory and field measurements have failed to measure pore‐water pressures within pipes and models of pipe flow have not addressed internal erosion or pipe clogging. The objective of this study was to model laboratory experiments of pipe flow in which clogging was observed in order to understand the clogging process. Richards' equation was used to model pipe flow, with the soil pipe represented as a highly conductive, low‐retention porous medium. The modeling used two contrasting boundary conditions, constant flux (CF) and constant head (CH), to quantify pressure buildups due to pipe clogging and differences in simulated pressures between the two imposed boundary conditions. Unique to these simulations was inclusion of pipe enlargement with time due to internal erosion, representation of partially full flow conditions, and inclusion of pipe clogging. Both CF and CH boundary conditions confirmed the concept of pressure buildup as a result of pipe clogging. Pressure jumps of around 54 m for CF and 18 cm for CH occurred in <0.1 s, while soil water pressures 4 cm radially outward from the pipe had not responded. These findings demonstrate the need to measure pressures within soil pipes due to hydraulic nonequilibrium between the pipe and soil matrix. Pore water pressures within the pipe below the clog rapidly (<0.25 s) drained to unsaturated conditions, indicating the ability of soil pipes to drain hillslopes and rapidly recover when clogs are flushed from the soil pipe. These dynamic processes need to be incorporated into stability models to properly model hillslope processes.
Nitrogen Uptake Efficiency of a Hybrid Compared with a Conventional, Pure‐Line Rice Cultivar
Authors: Norman Richard , Roberts Trenton , Slaton Nathan , Fulford Anthony
Published: May 2013

Hybrid rice (Oryza sativa L.) hectarage has increased substantially in the southern United States and necessitated research into the N nutrition of this new type of rice and how it compares to the traditional pure‐line rice. Consequently, a study was conducted utilizing 15N‐labeled urea applied at a range of N rates on two silt loam soils differing in native soil N to evaluate and compare the N fertilizer uptake efficiency, the native soil N uptake, and total N uptake of a RiceTec hybrid and a pure‐line rice cultivar. The hybrid (60.5 kg N ha−1) had greater soil N uptake compared with the pure‐line cultivar (51.7 kg N ha−1). The hybrid had a higher fertilizer N uptake efficiency (FNUE) compared with the pure‐line at the location with the lesser native soil N (62.2 vs. 56.2%, respectively), but had a similar FNUE at the location with the greater soil N (63.8 vs. 60.0%, respectively). Also, the pure‐line had a higher FNUE and greater N fertilizer response at the location with the greater soil N while the hybrid had a similar FNUE at both locations. The greater total N uptake by the hybrid compared with the pure‐line was due to greater soil N uptake at both locations and fertilizer N uptake at the location with the lower native soil N. The results suggest that if the native soil N is below a critical level a pure‐line rice cultivar might benefit from a higher rate of N fertilization to maximize FNUE.
Advances in Soil Evaporation Physics—A Review
Authors: Or Dani , Lehmann Peter , Shahraeeni Ebrahim , Shokri Nima
Published: May 2013

Globally, evaporation consumes about 25% of solar energy input and is a key hydrologic driver with 60% of terrestrial precipitation returning to the atmosphere via evapotranspiration. Quantifying evaporation is important for assessing changes in hydrologic reservoirs and surface energy balance and for many industrial and engineering applications. Evaporation dynamics from porous media reflect interactions between internal liquid and vapor transport, energy input for phase change, and mass transfer across air boundary layer. We reviewed recent advances on resolving interactions between soil intrinsic properties and evaporation dynamics with emphasis on the roles of capillarity and wettability affecting liquid phase continuity and capillary driving forces that sustain Stage I evaporation. We show that soil water characteristics contain information for predicting the drying front depth and mass loss at the end of Stage I and thus derive predictions for regional‐scale evaporative water losses from soil textural maps. We discuss the formation of secondary drying front at the onset of Stage II evaporation and subsequent diffusion‐controlled dynamics. An important aspect for remote sensing and modeling involves nonlinear interactions between wet evaporating surfaces and air boundary layer above (evaporation rate is not proportional to surface water content). Using pore scale models of evaporating surfaces and vapor transport across air boundary layer, we examined the necessary conditions for maintenance of nearly constant evaporation while the surface gradually dries and the drying front recedes into the soil. These new insights could be used to improve boundary conditions for models that are based on surface water content to quantify evaporation rates.
Sensitivity of the performance of a conceptual rainfall–runoff model to the temporal sampling of calibration data
Authors: Bastola Satish , Murphy Conor
Published: May 2013

The effect of the time step of calibration data on the performance of a hydrological model is examined through a numerical experiment where HYMOD, a rainfall–runoff model, is calibrated with data of varying temporal resolution. A simple scaling relationship between the parameters of the model and modelling time step is derived which enables information from daily hydrological records to be used in modelling at time steps much shorter than daily. Model parameters were found to respond differently depending upon the degree of aggregation of calibration data. A loss in performance, especially in terms of the Nash–Sutcliffe measure, is evident when behavioural simulators derived with one modelling time step are used for simulation at another time step. The loss in performance is greater when parameters derived from a longer time step were used for simulating flow with a shorter time step. The application of a simple scaling relationship derived from a multi-time step model calibration significantly decreased the loss in model performance. Such an approach may offer the prospect of conducting higher temporal resolution flood frequency analysis when finer scale data for model calibration are not available or limited.
Effect of water level regulation on gradients and levee deposits in the Lake Øyeren delta, Norway
Authors: Zinke Peggy , Bogen Jim
Published: May 2013

Water level changes resulting from a hydropower regulation have influenced water flow, gradients and sediment processes in the Lake Øyeren delta for about 150 years. They are reflected in the morphology of the islands on the delta plain. Under current regulation practices, water levels during the mean annual flood are maintained at about 1 m lower than during the previous regime prior to 1978. As the channels continue to mature, the recently deposited tongues and levees in the southern part will therefore probably maintain a distinctly lower elevation than that of the older islands. The influence of flood regulation on levee deposits during the extreme 1995 flood was estimated by comparing simulated overbank deposits resulting from different flood regulation schemes. The simulations showed that reduced water levels during floods in the presence of older islands extend the period of in-channel flow and promote the development of levee-like deposits in the lower part of the delta plain. This explains some of the characteristics observed in the morphological development, most notably the increased number of lagoons resulting from a higher number of levees.
Status of free-living amoebae (Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris) in drinking water supplies in Karachi, Pakistan
Authors: Yousuf Farzana Abubakar , Siddiqui Ruqaiyyah , Subhani Faysal , Khan Naveed Ahmed
Published: May 2013

The ability of pathogenic free-living amoebae to produce infections is a growing concern. In this study, we investigated the presence of free-living amoebae (Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris) in drinking water supplies in Karachi, Pakistan. Fifty-two domestic tap water samples were examined. Amoebae were identified by morphological characteristics and polymerase chain reaction. Thirty percent of the examined samples were positive for Acanthamoeba spp., 8% for N. fowleri while B. mandrillaris were not recovered. Additionally we examined secretory IgA antibody to Acanthamoeba and B. mandrillaris. Acanthamoeba antibody prevalence rate was 100% in both males and females, while B. mandrillaris antibody prevalence rate was 5.5% in males only (females were negative). Our findings suggest that free-living amoebae are a potential health hazard in domestic water supplies in Karachi, Pakistan.
Quantitative analysis of microbial contamination in private drinking water supply systems
Authors: Allevi Richard P. , Krometis Leigh-Anne H. , Hagedorn Charles , Benham Brian , Lawrence Annie H. , Ling Erin J. , Ziegler Peter E.
Published: May 2013

Over one million households rely on private water supplies (e.g. well, spring, cistern) in the Commonwealth of Virginia, USA. The present study tested 538 private wells and springs in 20 Virginia counties for total coliforms (TCs) and Escherichia coli along with a suite of chemical contaminants. A logistic regression analysis was used to investigate potential correlations between TC contamination and chemical parameters (e.g. NO3−, turbidity), as well as homeowner-provided survey data describing system characteristics and perceived water quality. Of the 538 samples collected, 41% (n = 221) were positive for TCs and 10% (n = 53) for E. coli. Chemical parameters were not statistically predictive of microbial contamination. Well depth, water treatment, and farm location proximate to the water supply were factors in a regression model that predicted presence/absence of TCs with 74% accuracy. Microbial and chemical source tracking techniques (Bacteroides gene Bac32F and HF183 detection via polymerase chain reaction and optical brightener detection via fluorometry) identified four samples as likely contaminated with human wastewater.
Breakthrough studies with mono-, binary- and ternary-ion systems comprised of Fe(II), F− and As(III) using river sand packed columns for groundwater treatment
Authors: Ahamad Kamal Uddin , Jawed Mohammad
Published: May 2013

Groundwater in Assam, India, contains excessive amounts of arsenic (As(III)), fluoride (F−) and iron (Fe(II)). The rural and semi-urban population of Assam uses indigenous iron filters fabricated using processed sand (PS) as one of the chief constituents to reduce Fe(II) concentration; however, no efforts have been made to reduce As(III) or F− concentrations before use. The present work is directed towards assessing the potential of PS for removal of these ions from mono-, binary- and ternary-ion systems through continuous mode column studies. Synthetic water samples containing fixed concentration of ions were prepared using deionized water. The observed order of breakthrough of ions was: As(III) followed by Fe(II) and F− followed by Fe(II) in the case of the binary ion systems of Fe(II) + As(III) and Fe(II) + F−. The throughput volume for As(III) in the (Fe(II) + As(III)) system and for F− in the (Fe(II) + F−) system is termed the critical breakthrough throughput volume. In the ternary ion system (Fe(II) + As(III) + F−), the order of breakthrough of ions observed was F−, then As(III) and then Fe(II) and hence the throughput volume F− is termed the critical breakthrough throughput volume. Results of column studies also indicate the impact on the uptake of the selected ion by the presence of the other ion present in the binary- and ternary-ion systems.
Survival of multi-drug resistant enteropathogenic Escherichia coli and Salmonella paratyphi in Vembanadu lake as a function of saltwater barrier along southwest coast of India
Authors: Chandran Abhirosh , Suson P. S. , Thomas A. P. , Hatha Mohamed , Mazumder Asit
Published: May 2013

The objective of the study was to evaluate the survival response of multi-drug resistant enteropathogenic Escherichia coli and Salmonella paratyphi to the salinity fluctuations induced by a saltwater barrier constructed in Vembanadu lake, which separates the lake into a freshwater dominated southern and brackish water dominated northern part. Therefore, microcosms containing freshwater, brackish water and microcosms with different saline concentrations (5, 10, 15, 20, 25 ppt) inoculated with E. coli/S. paratyphi were monitored up to 34 days at 20 and 30 °C. E. coli and S. paratyphi exhibited significantly higher (p < 0.05) survival at 20 °C compared to 30 °C in all microcosms. Despite fresh/brackish water, E. coli and S. paratyphi showed prolonged survival up to 34 days at both temperatures. They also demonstrated better survival potential at all tested saline concentrations except 25 ppt where a significantly higher (p < 0.0001) decay was observed. Therefore, enhanced survival exhibited by the multi-drug resistant enteropathogenic E. coli and S. paratyphi over a wide range of salinity levels suggest that they are able to remain viable for a very long time at higher densities in all seasons of the year in Vembanadu lake irrespective of saline concentrations, and may pose potential public health risks during recreational activities.
Antibiotic resistance genes in freshwater biofilms along a whole river
Authors: Winkworth Cynthia L.
Published: May 2013

A key problem challenging public health officials' efforts to stem the spread of antibiotic resistance is the potential increase of resistance in the environment. Yet, despite recent and significant changes to agricultural land in New Zealand, as well as the sector's high antibiotic use, the influence on antibiotic resistance in the environment remained uncharacterised. Spatial and temporal dynamics of antibiotic resistance genes in freshwater biofilms from NZ's fourth longest river as it transitioned between low and high intensity farming were examined for 1 year. Polymerase chain reaction was employed to gauge the level of resistance present. Biofilms were screened for 10 genes conferring resistance to antibiotics used in humans only and both humans and agricultural animals. Three genes were detected, one which conferred resistance to the important human-only use antibiotic vancomycin. Detected at the two downstream sites only, and those subject to the highest combined land-use stressors, the three genes indicated an elevated presence of antibiotic resistance in relation to surrounding land use; 7.7% versus 2% across the whole river system. The detection of a gene conferring resistance to an important human-only use antibiotic was particularly concerning and highlighted human-based contamination sources along the river, in addition to those of agricultural origin.
Editorial - Evaluating Impact of High-Cost Cancer Drugs at Regional Level: The Case of Veneto (Italy)
Authors: Gregori Dario , Chiffi Daniele
Published: May 2013

In Italy, the National Health System (NHS) costs are
controlled by the regional governments (which are
financially accountable for health care expenditure, including
hospital drug budgets), but agreements regarding price and
discounts are decided in AIFA (Italian Medicine Agency).
For this reason, some regional governments ask the
pharmaceutical companies to produce a "Health Technology
Assessment" before deciding to introduce a drug in the
regional hospital list of accepted drugs. Thus, in terms of
public policy maker and its decision process, the choice of
well-specified points of view is an essential ingredient in the
critical assessment of economic evaluation, which becomes
more effective when information is presented in the general
terms of a cost of illness analysis (COI), or, in a
disaggregated way by means of a list of the costs and the outcomes or consequences of the intervention, namely as a
cost consequence analysis (CCA).

Furthermore, while it has been observed that economic
evaluations are usually performed in different countries at
national level, in local health care decision making there is
lack of health economic data and evaluations, disconnecting
economic evaluations from the types of decision that local
institutions must normally face.

The University of Padova financed a composite and
interdisciplinary group of researchers to develop a proof-of-concept like program aimed at serving the Veneto region as a
template for the evaluation of the impact of (high-cost)
drugs. The program, financed as “Progetti di Ateneo” 2009,
(Code CPDA093183/09, "Modello per la valutazione
dell'impatto economico, sociale e di salute derivante
dall'utilizzo dei nuovi farmaci oncologici nella regione
Veneto") has come now to its end and this report represents
the outcome of a two-year intense research work.

Gratefully, the leading investigators acknowledge the
contribution of the entire EIHCD-VeRo Research Project
Agreement for their help and cooperation at the various
stages of the project development.
Role of Technical Assistance in the Establishment and Scale Up of
Programmatic Management of Drug Resistant Tuberculosis (PMDT) in
Ethiopia
Authors: Shimeles Ezra , Wondimagegn Getachew , Bedru Ahmed , Yilma Addisalem , Assefa Dawit , Abicho Tesfaye , Diro Ermias , Hashim Yasmin , Ombeka Victor , L'Herminez Rene , Klinkenberg Eveline
Published: May 2013

Implementation and scale up of programmatic management of drug resistant tuberculosis (PMDT) has proven
to be a challenge in many resource-constrained settings like in Ethiopia, despite the political commitment.

A critical programmatic gap analysis was conducted by technical experts to develop feasible recommendations for
incorporating multi drug resistant tuberculosis (MDR-TB) management in the national TB program following
international guidelines and receiving continuous technical and financial support.

The major achievement was building of technical capacity in the country at the level of a national MDR-TB technical
working group (TWG) as well as at the level of the MDR-TB treatment hospitals among the MDR management teams. In
addition, guideline development, improved access to second line drugs and renovation of health facilities in accordance
with TB infection control standards contributed to optimize implementation. Between February 2009 and September
2012, 575 MDR-TB patients accessed treatment under the program.

Building programmatic and clinical capacity at different levels of the health system in combination with strong political
commitment and partner's engagement were key elements of the PMDT approach. Structured technical assistance
combined with financial support during key steps was critical in the initiation and subsequent scale up of the program.
Increasing Tuberculosis Notification Rates Among Young Adults are Not
Associated with Migration in Da Nang, Vietnam
Authors: W. Tiemersma Edine , Duc Le Van , Sy Dinh Ngoc , Cobelens Frank G.J.
Published: May 2013

Tuberculosis (TB) case notification rates in Vietnam have stabilized since 2000, but in 2007 were increasing
among young adults. The emerging HIV epidemic only partly explains this increase. Other factors are probably involved.
We aimed to assess whether rural-to-urban migration is such a factor.

We conducted a case-control study at district TB units (DTUs) in Da Nang province, Vietnam, recruiting equal numbers
(170) of TB patients aged 15-35 years, TB suspects of the same age in whom TB was excluded, and TB patients of 35
years and older. Risk factors for TB were assessed through interviews using pre-structured questionnaires.

Among persons seeking care at DTUs, migration was not a significant risk factor for TB. Young male migrants had a
lower risk of TB than other young adults (odds ratio (OR) 0.4; 95% confidence interval (95%CI) 0.03-0.64). Instead, TB
was associated with male sex and a higher level of education. Compared to older TB patients, younger TB patients were
more likely to be female, have a higher education level and a job involving indoor contacts with other people.

Migration does not account for the increase in TB case notification rates among young adults in Vietnam. However,
migration cannot be excluded as a risk factor for TB in Vietnam, because migrants may not seek diagnosis and treatment
for TB at DTUs.
Return on Investments in Technical Assistance for TB Capacity Building?
Factors Influencing Kenyan Health Workers' Performance of TB Skills
Authors: Mitchell Ellen M.H. , Colvin Charlotte E. , Klinkenberg Eveline , Heus Marleen , Sitenei Joseph
Published: May 2013

The dearth of trained personnel to implement TB/HIV services led to substantial investment in human
resources and technical assistance in Kenya. Between 1999 and 2006 the staff of the TB program almost doubled.
Increases in quantity of TB services occurred, but the impact on quality was unclear.

Analysis of nationally representative data from the 2004 Kenya Service Provisions Assessment (KSPA) of 1,332 TB
and/or HIV service providers within 440 public and private health facilities was conducted to compare performance of TB
duties between those with and without TB and/or HIV training.

Although the TB-HIV workforce was disproportionately female (56.9%), participation in training was less common
among women of all cadres (OR 0.41 95%CI .22-.78). After controlling for structural and organizational factors, training
in TB diagnosis was strongly associated with performance of smear microscopy (aOR 3.4 95%CI 1.6-7.3). Mid-level
health workers were less likely than doctors to rely on smear microscopy for diagnosis (aOR 0.4 95%CI 0.2-0.6). Training
was associated with direct observation of treatment (D.O.T) (aOR 3.3 CI 1.3-8.9). Other factors positively associated with
performance of D.O.T included receipt of supportive supervision (aOR 3.2 CI 2.0-5.0) and an adequate TB drug supply
(aOR1.2 95%CI 1.1-1.4). Barriers included non-alignment with the national directly observed short course policy program
(DOTS) (aOR.0.2 95%CI 0.1-0.7) and working where high volumes of smear microscopy were performed (aOR 0.7
95%CI 0.5-1.0).

Investments in capacity building including technical assistance during the 2000-2003 period were associated with
performance of smear microscopy and directly observed therapy in 2004. However health system factors also influence
performance.
Skin Scrape Test: An Inexpensive and Painless Skin Test For Recognition Of Immediate Hypersensitivity In Children And Adults
Authors: Olivier Celso Eduardo , Argentão Daiana Guedes Pinto , Acácia Pereira Goncalves dos Santos Raquel , Dias da Silva Mariana , Patussi Santos Lima Regiane , de Lima Zollner Ricardo
Published: May 2013

Background:

Skin testing is a mainstay in allergology, and its importance is increasing in several fields. The
ability to choose the most suitable technique according to the clinical setting is an advantage for the medical team.

Objectives:

To describe in detail an alternative technique of the coetaneous allergy test (skin scrape test) conceived as a
variation of the former skin scratch test; to evaluate its value as a tool for diagnosis of immune sensitization; and to compare
its accuracy with the skin prick test.

Methods:

The skin scrape test and skin prick test were performed side by side with the same allergen extracts in 162 human
subjects classified in two groups according to the known presence or absence of serum specific-IgE to these allergens.

Results:

The sensitivity of the skin scrape test to detect immediate reactions was 85.0%. The sensitivity of the skin prick
test was 86.5%. The sensitivity of both techniques analyzed together as a unique procedure was 94.2%. The specificity of
the skin scrape test was 90.1%.The specificity of the skin prick test was 72.9%.The specificity of both tests analyzed together
as a unique procedure was 70.5%.

Conclusions:

The skin scrape test is an alternative and complementary technique for allergic skin testing, and it is able to
detect IgE-specific immune sensitization without the disadvantages of the skin scratch test. The skin scrape test has similar
outcomes to the skin prick test.
Commentary on Fukushima and Beneficial Effects of Low Radiation
Authors: Cuttler Jerry M.
Published: May 2013

Approximately 160,000 people evacuated the area around the Fukushima Dai-ichi NPP shortly after it was damage by the earthquake and tsunami. The evacuation order applied to 70,000 of them, while the other 90,000 left voluntarily and returned soon afterward. After more than two years, most of the 70,000 are still not allowed to return to their homes. The 1100 disaster-related deaths caused by the evacuation order show that this precautionary action, taken to minimize cancer risks, was not “conservative.” In this paper, recent studies are reviewed on the consequences of the radioactive releases and on the benefits of many medical treatments with low doses of radiation that were carried out until the 1950s, before the radiation scare was created. Recent research has shed light on the high rate of spontaneous double-strand breaks in DNA and the adaptive protections in cells, tissues and humans that are up-regulated by low radiation. These defences prevent, repair, remove and replace damage, from all causes including external agents. Cancer mortality is reduced. The ICRP's concept of radiation risk is wrong. It should revert to its 1934 concept, which was a tolerance dose of 0.2 roentgen (r) per day based on more than 35 years of medical experience.
GFR Estimating Equations
Authors: Rule Andrew D. , Glassock Richard J.
Published: May 2013

The application of serum creatinine and cystatin C in patients with CKD has been limited to using estimated glomerular filtration rate (eGFR). Criteria for choosing the best GFR estimating equation are 1) accuracy in estimating measured GFR, 2) optimal discrimination of clinical outcomes, and 3) association with CKD risk factors and outcomes similar to that of measured GFR. Notably, these criteria are often not in agreement; and while the last criterion is the most important, it has been widely overlooked. The primary problem with eGFR is that the non-GFR determinants of serum creatinine and cystatin C, as well as their surrogates (age, sex, and race), associate with CKD risk factors and outcomes. This leads to a distorted understanding of CKD, though eGFR based on serum creatinine appears to be less biased than eGFR based on cystatin C. Because of this problem, the use of eGFR should be limited to settings where knowing actual GFR is relevant and eGFR is more informative about GFR than serum creatinine or cystatin C alone. Such settings include staging CKD severity by GFR and dosing medications cleared by glomerular filtration. Alternatively, the diagnosis of CKD, the longitudinal progression of CKD, and prognostic models for CKD are settings where serum creatinine and cystatin C can be better applied and interpreted without eGFR.
Extracorporeal Therapy for Dabigatran Removal in the Treatment of Acute Bleeding
Authors: Singh Tripti , Maw Thin Thin , Henry Brian L. , Pastor-Soler Núria M. , Unruh Mark L. , Hallows Kenneth R. , Nolin Thomas D.
Published: May 2013

Background and objectives

Dabigatran is an oral direct thrombin inhibitor that is Food and Drug Administration-approved for prevention of stroke in patients with atrial fibrillation. No antidote is available for reversal of dabigatran’s anticoagulant effect. Despite limited clinical data, hemodialysis has been suggested as a strategy to remove dabigatran during acute bleeding. This work presents five cases, in which extracorporeal therapy was performed for dabigatran removal in acutely bleeding patients.

Design, setting, participants, & measurements

The series is comprised of five consecutive cases of patients receiving dabigatran 150 mg per os two times daily who were admitted with life-threatening bleeding between March of 2012 and January of 2013. Dabigatran plasma concentrations ranged from 149 to 1200 ng/ml. Treatment included administration of blood products to all patients and then, high-flux intermittent hemodialysis alone or followed by continuous renal replacement therapy.

Results

Dabigatran concentrations decreased by 52%–77% during intermittent hemodialysis but rebounded up to 87% within 2 hours after completion of dialysis. Initiation of continuous renal replacement therapy after intermittent hemodialysis attenuated the rebound effect in one patient and contributed to a reduction in dabigatran concentrations of 81% over 30 hours.

Conclusions

Extracorporeal therapy lowered dabigatran concentrations, suggesting that it removed the drug and may effectively accelerate total clearance, especially in patients with impaired kidney function. The use of prolonged intermittent hemodialysis or intermittent hemodialysis followed by continuous renal replacement therapy is recommended for the management of life-threatening bleeding in patients receiving dabigatran. The advantage of extracorporeal therapy should be weighed against the risk of bleeding with catheter insertion.
Association of Left Ventricular Longitudinal Strain with Mortality among Stable Hemodialysis Patients with Preserved Left Ventricular Ejection Fraction
Authors: Liu Yen-Wen , Su Chi-Ting , Sung Junne-Ming , Wang Saprina P.H. , Su Yu-Ru , Yang Chun-Shin , Tsai Liang-Miin , Chen Jyh-Hong , Tsai Wei-Chuan
Published: May 2013

Background and objectives

Little is known about the optimal echocardiographic parameters for risk stratification in stable dialysis patients with preserved left ventricular ejection fraction (LVEF) (ejection fraction ≥50%). Left ventricular (LV) global peak systolic longitudinal strain (GLS) is the ratio of the maximal change in myocardial longitudinal length in systole to the original length and reliably and accurately assesses LV function. During systole, LV myocardium in the longitudinal direction shortens and GLS is represented by a negative value. The more negative value of GLS, the better the LV function is. This study hypothesized that subtle abnormalities of GLS are associated with an adverse prognosis.

Design, setting, participants, & measurements

This prospective study collected clinical and echocardiographic data (including GLS) from 88 stable hemodialysis patients (mean age 67.0±11.2 years; 35% men) with preserved LVEF. These patients were enrolled from December 2008 to January 2009 and were followed-up for 25.6±9.9 months. The primary outcome was all-cause mortality. Multivariate Cox regression analysis was used to investigate risk factors for mortality.

Results

The mortality group (n=24) had lower albumin levels, less negative GLS, and higher prevalence of coronary artery disease and diabetes mellitus than the survival group. Using a GLS cutoff value of −15%, the less negative GLS group (GLS ≥−15%) had a higher mortality rate. Cox regression analyses revealed that lower albumin level (hazard ratio, 0.16; 95% confidence interval, 0.05 to 0.53; P=0.003) and less negative GLS (hazard ratio, 3.57; 95% confidence interval, 1.41 to 9.04; P=0.01) were independent predictors of all-cause mortality. Furthermore, less negative GLS was associated with a higher cardiovascular death rate.

Conclusions

Less negative GLS is predictive of poor prognosis among stable hemodialysis patients with preserved LVEF.
From Choice to Change: An Analysis of the ‘choice’ Discourse in Canada's 2006 Federal Election
Authors: Richardson Brooke , Langford Rachel , Friendly Martha , Rauhala Ann
Published: May 2013

A critical discourse analysis (CDA) was used to analyze the representation of Early Childhood Education and Care (ECEC) in the 2006 federal election in Canada. Guided by Fairclough's approach to CDA, this study analyzed written documents including newspaper articles from The Globe and Mail and The National Post, the policy platforms of the Liberal and Conservative parties, and political speeches from party leaders. Four textual and discourse processes were found to legitimize the ‘choice’ discourse and contribute to its dominance: conversationalization, nominalization, use of irrealis statements and recontextualization. It is concluded that a fundamental shift in discourse related to political and media discussion of ECEC policy in Canada is needed if progressive policy changes are to take place.
Orthodontic pain: an interaction between age and sex in early and middle adolescence
Authors: Sandhu Satpal S , Sandhu Jasleen
Published: May 2013

Objective:

To investigate the age and sex interaction effect on orthodontic pain in adolescence during the initial phase of fixed orthodontic treatment.

Materials and Methods:

Three hundred participants (mean age 13.85 ± 1.98 years; 152 female, 148 male) met all inclusion criteria and enrolled in the study designed as 2 × 2 factorial trial with two levels each for age (11–14 years; 14–17 years) and sex (male; female). A 0.16-inch superelastic NiTi wire was used in a 0.022-inch slot (Roth's prescription) preadjusted edgewise appliance for initial leveling and alignment of mandibular anterior dentition. The follow-up period was 7 days. Pain was assessed by using 100 mm visual analog scale for one baseline and nine follow-up repeated measurements at prespecified time points. Data were analyzed by using generalized linear mixed effect model analysis.

Results:

Three participants were lost to follow-up, and 17 participants were not considered for analysis due to incomplete or improperly completed questionnaire. Therefore, 280 participants (mean age 13.96 ± 2.01 years; 138 female, 142 male) were analyzed for results. Results showed that age and sex interaction had statistically significant effect on pain (F  =  3.56; P  =  .0151; df 3/218). In the 11–14 year age group, there was no significant difference for pain between male and female. In the 14–17 year age group, girls reported significantly greater pain compared to 14- to 17 year-old boys (t  =  2.76; P  =  .0209). Pain reported by 14- to 17-year-old girls was also significantly greater compared to 11- to 14-year-old boys (t  =  2.91; P  =  .0206).

Conclusions:

Age and sex interaction has significant effect on orthodontic pain during adolescence, and 14- to 17-year-old girls experienced maximum pain.
Outcome Measures for Individuals With Stroke: Process and Recommendations From the American Physical Therapy Association Neurology Section Task Force
Authors: Sullivan Jane E. , Crowner Beth E. , Kluding Patricia M. , Nichols Diane , Rose Dorian K. , Yoshida Rie , Pinto Zipp Genevieve
Published: May 2013

Background and Purpose

The use of standardized outcome measures (OMs) can support clinicians’ development of appropriate care plans, guide educators in curricular decisions, and enhance the methodological quality and generalizability of clinical trials. The purposes of this case report are: (1) to describe a framework and process for assessing psychometrics and clinical utility of OMs used poststroke; (2) to describe a consensus process used to develop recommendations for stroke-related OMs in clinical practice, research, and professional (entry-level) physical therapist education; (3) to present examples demonstrating how the recommendations have been utilized to date; and (4) to make suggestions for future efforts.

Case Description

A task force of 7 physical therapists with diverse clinical and research expertise in stroke rehabilitation used a 3-stage, modified Delphi consensus process to develop recommendations on OM use. An evidence-based systematic review template and a 4-point rating scheme were used to make recommendations on OM use by care setting and patient acuity, for research, and for inclusion in professional education.

Outcomes

An initial list of 77 OMs was developed based on input from numerous professional sources. Screening measures and duplicate measures were eliminated. Fifty-six OMs received full review. Measures spanned the constructs of body structure/function (21), activity (28), and participation (14). Fourteen measures received a rating of “highly recommend.”

Discussion

Use of highly recommended OMs may provide a common set of tools enabling comparisons across patients, interventions, settings, and studies. The use of a clearly defined, comprehensive assessment template may facilitate the pooling of data on OMs and contribute to best practice guidelines. Educational recommendations may inform curricular decisions.
What Is Meant by Argumentative Competence? An Integrative Review of Methods of Analysis and Assessment in Education
Authors: Rapanta Chrysi , Garcia-Mila Merce , Gilabert Sandra
Published: May 2013

The need to enhance argument skills through education has become increasingly evident during the past 20 years. This need has resulted in an ongoing discussion that focuses on students’ and teachers’ argumentation and its support. However, apart from the extended competence-based discourse, no clear and homogeneous definition exists for argumentative competence and its constituent skills. To respond to this deficiency, we conducted an integrative literature review focusing on the methods of argument analysis and assessment that have been proposed thus far in the field of education. Specifically, we constructed an interpretative framework to organize the information contained in 97 reviewed studies in a coherent and meaningful way. The main result of the framework’s application is the emergence of three levels of argumentative competence: metacognitive, metastrategic, and epistemological competence. We consider this result the beginning of further research on the psycho-pedagogical nature of argument skills and their manifestation as competent performance.
Effective treatment of refractory intracranial hypertension after traumatic brain injury with repeated boluses of 14.6% hypertonic saline
Authors: Eskandari Ramin , Filtz Michael R. , Davis Gary E. , Hoesch Robert E.
Published: May 2013

Object

Normal intracranial pressure (ICP) and cerebral perfusion pressure (CPP) have been identified as favorable prognostic factors in the outcome of patients with traumatic brain injuries (TBIs). Osmotic diuretics and hypertonic saline (HTS) are commonly used to treat elevated ICP in patients with TBI; however, sustained effects of repeated high-concentration HTS boluses for severely refractory ICP elevation have not been studied. The authors' goal in this study was to determine whether repeated 14.6% HTS boluses were efficacious in treating severely refractory intracranial hypertension in patients with TBI.

Methods

In a prospective cohort study in a neurocritical care unit, adult TBI patients with sustained ICP > 30 mm Hg for more than 30 minutes after exhaustive medical and/or surgical therapy received repeated 15-minute boluses of 14.6% HTS over 12 hours through central venous access.

Results

Response to treatment was evaluated in 11 patients. Within 5 minutes of bolus administration, mean ICP decreased from 40 to 33 mm Hg (30% reduction, p < 0.05). Intracranial pressure–lowering effects were sustained for 12 hours (41% reduction, p < 0.05) with multiple boluses (mean number of boluses 7 ± 5.5). The mean CPP increased 22% and 32% from baseline at 15 and 30 minutes, respectively (p < 0.05). The mean serum sodium level (SNa) at baseline was 155 ± 7.1 mEq/L, and after multiple boluses of 14.6% HTS, SNa at 12 hours was 154 ± 7.1 mEq/L. The mean heart rate, systolic blood pressure, blood urea nitrogen, and creatinine demonstrated no significant change throughout the study.

Conclusions

The subset of TBI patients with intracranial hypertension that is completely refractory to all other medical therapies can be treated effectively and safely with repeated boluses of 14.6% HTS rather than a one-time dose.
Anterior temporal lobectomy with amygdalohippocampectomy for mesial temporal sclerosis: predictors of long-term seizure control
Authors: Elliott Robert E. , Bollo Robert J. , Berliner Jonathan L. , Silverberg Alyson , Carlson Chad , Geller Eric B. , Barr William B. , Devinsky Orrin , Doyle Werner K.
Published: May 2013

Object

In this paper the authors' goal was to identify preoperative variables that predict long-term seizure freedom among patients with mesial temporal sclerosis (MTS) after single-stage anterior temporal lobectomy and amygdalohippocampectomy (ATL-AH).

Methods

The authors retrospectively reviewed 116 consecutive patients (66 females, mean age at surgery 40.7 years) with refractory seizures and pathologically confirmed MTS who underwent ATL-AH with at least 2 years of follow-up. All patients underwent preoperative MRI and video-electroencephalography (EEG); 106 patients (91.4%) underwent Wada testing and 107 patients (92.2%) had neuropsychological evaluations. The authors assessed the concordance of these 4 studies (defined as test consistent with the side of eventual surgery) and analyzed the impact of preoperative variables on seizure freedom.

Results

The median follow-up after surgery was 6.7 years (mean 6.9 years). Overall, 103 patients (89%) were seizure free, and 109 patients (94%) had Engel Class I or II outcome. Concordant findings were highest for video-EEG (100%), PET (100%), MRI (99.0%), and Wada testing (90.4%) and lowest for SPECT (84.6%) and neuropsychological testing (82.5%). Using binary logistic regression analysis (seizure free or not) and Cox proportional hazard analysis (seizure-free survival), less disparity in the Wada memory scores between the ipsilateral and contralateral sides was associated with persistent seizures.

Conclusions

Seizure freedom of nearly 90% can be achieved with ATL-AH in properly selected patients with MTS and concordant preoperative studies. The low number of poor outcomes and exclusion of multistage patients limit the statistical power to determine preoperative variables that predict failure. Strong Wada memory lateralization was associated with excellent long-term outcome and adds important localization information to structural and neurophysiological data in predicting outcome after ATL-AH for MTS.
The relationship between the superior petrosal sinus and the porus trigeminus: an anatomical study
Authors: Tubbs R. Shane , Mortazavi Martin M. , Krishnamurthy Sanjay , Verma Ketan , Griessenauer Christoph J. , Cohen-Gadol Aaron A.
Published: May 2013

Object

During intracranial approaches to the skull base, vascular relationships are important. One relationship that has received scant attention in the literature is that between the superior petrosal sinus (SPS) and the opening of the Meckel cave (that is, the porus trigeminus).

Methods

Cadaver dissections were performed in 25 latex-injected adult cadaveric heads (50 sides). Specifically, the relationship between the SPS and the opening of the Meckel cave was observed. The goal was to enhance knowledge of the relationship between the SPS and the opening of the Meckel cave.

Results

Of the 50 sides, 68%, 18%, and 16% of SPSs traveled superior to, inferior to, and around the opening to the Meckel cave, respectively. In the latter cases, a venous ring was formed around the proximal trigeminal nerve. No sinus entered the Meckel cave. In general, the porus trigeminus was narrowed on sides found to have an SPS that encircled this region. Sinuses that traveled only inferior to the porus were in general smaller than sinuses that traveled superior or encircled this opening. No statistically significant differences were noted between the various sinus relationships and sex, age, or side of the head.

Conclusions

Knowledge of the relationship between the SPS and the opening of the Meckel cave may be useful to the skull base surgeon. Based on this study, some individuals may retain the early embryonic position of their SPS in relation to the trigeminal nerve.
Gamma Knife surgery for large vestibular schwannomas: a single-center retrospective case-matched comparison assessing the effect of lesion size
Authors: Williams Brian J. , Xu Zhiyuan , Salvetti David J. , McNeill Ian T. , Larner James , Sheehan Jason P.
Published: May 2013

Object

Gamma Knife surgery (GKS) is a safe and effective treatment for patients with small to moderately sized vestibular schwannomas (VSs). Reports of stereotactic radiosurgery for large VSs have demonstrated worse tumor control and preservation of neurological function. The authors endeavored to assess the effect of size of VSs treated using GKS.

Methods

This study was a retrospective comparison of 24 patients with large VSs (> 3 cm in maximum diameter) treated with GKS compared with 49 small VSs (≤ 3 cm) matched for age, sex, radiosurgical margin and maximal doses, length of follow-up, and indication.

Results

Actuarial tumor progression-free survival (PFS) for the large VS cohort was 95.2% and 81.8% at 3 and 5 years, respectively, compared with 97% and 90% for small VSs (p = 0.009). Overall clinical outcome was better in small VSs compared with large VSs (p < 0.001). Patients with small VSs presenting with House-Brackmann Grade I (good facial function) had better neurological outcomes compared with patients with large VSs (p = 0.003). Treatment failure occurred in 6 patients with large VSs; 3 each were treated with resection or repeat GKS. Treatment failure did not occur in the small VS group. Two patients in the large VS group required ventriculoperitoneal shunt placement. Univariate analysis did not identify any predictors of treatment failure among the large VS cohort.

Conclusions

Patients with large VSs treated using GKS had shorter PFS and worse clinical outcomes compared with age-, sex-, and indication-matched patients with small VSs. Nevertheless, GKS has efficacy for some patients with large VSs and represents a reasonable treatment option for selected patients.