2-step Approach Research Articles

Regional water resources assessments using an uncertain modelling approach: The example of Swaziland

Study regionThe 5 river basins that flow through or within Swaziland in southern Africa. Study focusA regional water resource assessment using an uncertainty version of the Pitman monthly rainfall-runoff model whose outputs are constrained by six indices of natural hydrological response (mean monthly runoff, mean monthly groundwater recharge, Q10, Q50 and Q90 percentage points of the flow duration curve and% time of zero flows) for each of the 122 sub-basins within the whole of Swaziland. A 2-step approach is adopted where the first step establishes behavioural, but uncertain, model parameter ranges for natural incremental sub-basin hydrological responses, while the second step links all the sub-basin outputs to generate cumulative sub-basin outflows and allows for water use parameters to be included. New hydrological insights for this regionThe analysis of hydrological indices highlights the regional variations in hydrological processes and sub-basin response. The adopted modelling approach provides further insight into all of the uncertainties associated with quantifying the available water resources of Swaziland. The study has provided more insight into the spatial variability of the hydrological response and existing development impacts than was previously available. These new insights should provide an improved basis for future water management in Swaziland.

Laparoscopic sleeve gastrectomy: gateway to kidney transplantation

BackgroundThe prevalence of obesity and obesity-related morbidity in end-stage renal disease patients is rising. Although it is established that obesity does not abrogate the transplant benefit with respect to lower long-term mortality and cardiovascular risk, it is associated with increased graft failure, delayed graft function, surgical complications, prolonged hospital stay, and costs. ObjectivesTo examine the safety and efficacy of LSG (laparoscopic sleeve gastrectomy) in renal transplant candidates and evaluate transplant outcomes. SettingSingle-center prospective nonrandomized trial MethodsWe here report on a prospective single-center trial establishing a 2-step approach for obese renal transplant candidates. Patients with end-stage renal disease and a BMI (body mass index) of 35 kg/m2 or higher underwent laparoscopic sleeve gastrectomy. After reaching a BMI of<35 kg/m2, patients were waitlisted for kidney transplantation. Age, gender, body mass index (BMI), associated co-morbidities, cause of end-stage renal disease, surgical complications, and outcome after kidney transplantation (graft survival, incidence of delayed graft function, incidence of rejection, serum creatinine) were collected. ResultsLSG was performed in 8 renal transplant candidates with a mean BMI of 38.8 kg/m2 each. BMI dropped to below 35 kg/m2 within a median of 3 months. Percent excess body mass index loss (%EBMIL) was 62.7% at 1 year after LSG. Within 17 months (mean) after metabolic surgery, 7 patients underwent kidney transplantation. All transplants were successful with a serum creatinine of 1.9±.8 mg/dL at discharge and stable allograft function thereafter. Mean follow-up was 3.2±1.4 years; no patient was lost to follow-up. ConclusionLSG is safe and efficacious for treatment of obesity in renal transplant candidates. Rapid and sustained weight loss and subsequent waitlisting for kidney transplantation may reduce overall and in particular posttransplant patient morbidity.

An improved visualization-based approach for project portfolio selection

We propose a 2-step interactive approach for solving a project portfolio selection problem as a single-criterium optimization problem. Our approach innovates by using two coordinated charts: an interactive project timeline with drag-and-drop functionalities for project reallocation in time; and an interactive cost and risk chart that combines line charts and bar charts in order to present multidimensional time-based datasets. We also use bar charts related to the allocation of man-hour resources. These functionalities enable users to refine the model that is fed into optimization software in order to achieve results that better correspond to their expectations. We discuss results of a heuristic-based usability evaluation of our prototype, its use in real scenarios, and present preliminary positive feedback from users.

Game Outcome Uncertainty and the Demand for International Football Games: Evidence From the German TV Market

ABSTRACTThis article adopts a comprehensive 2-step approach to dissolve recent confusion regarding the role of game outcome uncertainty in the TV demand for international team sports. Analyzing the German TV demand for 457 international football games broadcasted during 6 Fédération Internationale de Football Association World Cups and 5 Union des Associations Européennes de Football European Championships and 287 international games played by the Germany national football team, this study reveals that solely the demand for friendly games is affected by increasing uncertainty regarding the expected game outcomes.

Sensitivity, Specificity, and Limitations of Optical Coherence Tomography Angiography in Diagnosis of Polypoidal Choroidal Vasculopathy.

Purpose To evaluate the sensitivity and specificity of optical coherence tomography angiography (OCTA) in differentiating polypoidal choroidal vasculopathy (PCV) from age-related macular degeneration (AMD). Methods Fundus color photographs, spectral-domain optical coherence tomography, and fluorescein angiography (step 1) and OCTA (step 2) of 50 eyes that had PCV or AMD were presented to two ophthalmologists. The final diagnoses of PCV were masked. Sensitivity and specificity were calculated and compared to the 2-step approach (before and after OCTA) in detecting PCV. The limitations were also evaluated. Results Of the 50 eyes, 31 were PCV and 19 were non-PCV. The sensitivity increased from 69.5% to 90% after OCTA; however, there was no significant improvement in specificity after OCTA. 70.9% of the eyes with PCV had clear or obvious branching vascular nets (BVNs) in OCTA with high sensitivity (97.5%) after OCTA. Contrarily, 29.1% had insignificant BVNs with a low sensitivity (72.5%) after OCTA. 27% of the occult choroidal neovascularization (CNV) cases were overdiagnosed as PCV when OCTA was applied. Conclusions OCTA based on clear BVNs at the choroidal level increased sensitivity of diagnosis of PCV by 20%. However, the false-positive rate also increased in occult CNV. Several limitations for a correct diagnosis of PCV were noted.

Do Macroprudential Policy Instruments Affect the Link between Lending and Capital Ratio? Cross-Country Evidence

In this paper we ask about the capacity of macroprudential policies to reduce the positive association between loans growth and the capital ratio. We focus on aggregated macroprudential policy measures and on individual instruments and test whether their effect on the association between lending and capital depends on bank size, the economic development of a country as well as on the extent of capital account openness. Applying the GMM 2-step Blundell and Bond approach to a sample covering over 60 countries, we find that macroprudential policy instruments reduce the impact of capital on bank lending during both crisis and non-crisis times. This result is stronger in large banks than in other banks. Of individual macroprudential instruments, only borrower-targeted LTV caps and DTI ratio weaken the association between lending and capital. Our results also show that the effect of macroprudential policies on the association between lending and the capital ratio in non-crisis periods is stronger in advanced countries than in emerging countries. Additionally, differentiating by the level of capital account openness, we find that macroprudential policies are more effective in increasing the resilience of banks and thus weakening the association between loan supply and capital ratio for relatively closed economies but less effective for relatively open economies. Generally, with our study we are able to support the view that macroprudential policy has the potential to curb the procyclical impact of bank capital on lending and therefore, the introduction of more restrictive international capital standards included in Basel III and of macroprudential policies are fully justified.

Analysis of the Impact of KIR B Haplotype Donors on Outcomes after Haploidentical (HI) and Matched Related (MR) Hematopoietic Stem Cell Transplantation (HSCT)

Introduction:Natural killer (NK) cell alloreactivity has been associated with graft versus leukemia effects in HSCT. These effects are in part mediated through killer cell immunoglobulin-like receptors (KIR) on the surface of NK cells. The absence of inhibition of NK cells via inhibitory KIR in KIR ligand mismatched T-cell depleted HI HSCT, and the use of unrelated donors possessing activating KIR haplotypes (KIR-B) have been associated with improved overall survival (OS) due to relapse protection. Inhibitory KIR ligand mismatch in the setting of T-cell replete HI HSCT has not consistently been shown to be beneficial, and data regarding the impact of using KIR-B donors in T-replete HI and MR HSCT is limited. In this preliminary retrospective review, we compared outcomes between patients with KIR-B donors versus KIR A haplotype (KIR-A) donors after HI and MR HSCT to help inform donor selection.Methods:All patients underwent HSCT on our 2-step approach in which after conditioning, a fixed T cell dose (2 x 108/kg) is administered (step 1), followed 2-3 days later by cyclophosphamide (CY) for bidirectional tolerization. Two days after CY, patients receive a CD 34-selected donor product (step 2). To be included in the analysis, patients had to be alive for at least 1 month post HSCT and be without evidence of graft rejection. Recipients were divided into 2 groups based on whether they were transplanted from a KIR-B (possessing one or more non-framework activating KIR genes) versus a KIR-A donor (genotypically negative for non-framework activating KIR genes). The relationship between the use of a KIR-B donor and the end points of OS, relapse, grades II-IV acute graft versus host disease (GVHD), chronic GVHD and non-relapse mortality (NRM) was examined. Probability of OS was estimated by Kaplan-Meier (KM) method with log-rank analysis and multivariate analyses using Cox proportional hazards. Donor and recipient age and gender, HCT-CI score, Revised Disease Risk Index, presence of any inhibitory KIR ligand mismatch between donor and recipient and CMV reactivation after HSCT were considered as confounding variables. Cumulative incidence functions with competing risk analyses were used to estimate the probabilities of relapse, NRM, acute and chronic GVHD.Results:The study group consisted of 128 consecutive patients with myeloid malignancies (AML=91 MDS=27, CML=1, MPD=9) undergoing HI [n=84] or MR [n=44] HSCT. The median recipient age and follow-up of the study group was 58 (range 19-78) years and 40.6 (range: 1.07-117.27) months respectively. Only 13 (10.2%) patients had grade III or higher acute GVHD and only 7 (5.5%) patients developed severe, chronic GVHD (score of 3) respectively. Seventy-four (58%) and 54 (42%) of recipients had KIR-B versus KIR-A donors respectively. Fifty-five (74.3%) KIR-B donors possessed HLA C1 or C1/2 alleles in the presence of KIR2L2/3/2DS2. On multivariate Cox regression analysis, OS (HR, 0.579; 95% CI, 0.337-0.995; P= 0.048) was significantly higher in patients who received HSCT from KIR-B donors. On competing risk analysis, relapse (HR, 0.756; P=0.403) and NRM (HR, 0.466; P=0.128) were lower in patients who had KIR haplotype B donors though not statistically significant. In contrast, the risk of grades II to IV acute GVHD (with death as a competing event) was higher in patients with KIR-B donors (HR, 1.972; 95% CI, 1.009-3.852; P=0.047). Similarly transplants from KIR-B donors were associated with a higher risk of chronic GVHD (HR, 2.89; P=0.053).Discussion:Our results show that within the context of the 2-step approach, the use of a KIR-B donor is associated with improved OS and an increased risk of acute and chronic GVHD in patients with myeloid neoplasms receiving HI and MR HSCT. While not reaching significance, the results for relapse and NRM suggest that the OS benefit in patients with KIR-B donors was derived from a combination of lower relapse rates and NRM that was not adversely impacted by GVHD which was mostly lower grade in this population. Our findings support the concept of KIR-B donors as more alloreactive than KIR-A donors, specifically those possessing a C1-C1/2/2DL2/3/2DS2 repertoire, the primary type possessed by KIR-B donors in this analysis. The data argues for the continued use of KIR genotyping at our institution and analyses of HSCT outcomes based on donor KIR repertoire and other donor characteristics to optimize donor selection in HI and MR HSCT. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The association between maternal hyperglycemia and perinatal outcomes in gestational diabetes mellitus patients: A retrospective cohort study.

Pregnancies complicated by gestational diabetes mellitus (GDM) are associated with increased risks of adverse maternal and fetal outcomes. The risks of adverse pregnancy outcomes differ depending on the glucose values among GDM patients. For accurate and effective prenatal counseling, it is necessary to understand the relationship between different maternal hyperglycemia values and the severity of adverse outcomes. With this objective, this study reexamines the relationship between maternal hyperglycemia versus maternal and perinatal outcomes in GDM patients. For this study, maternal hyperglycemia was diagnosed using the 2-step diagnostic approach.Medical records of 3434 pregnant women, who received the 50-g glucose challenge test (GCT) between March 2001 and April 2013, were reviewed. As a result, 307 patients were diagnosed with GDM, and they were divided into 2 groups according to their fasting glucose levels. A total of 171 patients had normal fasting glucose level (<95 mg/dL), and 136 patients had abnormal fasting glucose level (≥95 mg/dL). The 50-g GCT results were subdivided by 20-unit increments (140–159, n = 123; 160–179, n = 84; 180–199, n = 50; and ≥200, n = 50), and the maternal and perinatal outcomes were compared against the normal 50-g GCT group (n = 307).Maternal fasting blood glucose (FBG) level showed clear association with adverse perinatal outcomes. The odds ratio (OR) of macrosomia was 6.72 (95% CI: 2.59–17.49, P < 0.001) between the 2 groups. The ORs of large for gestational age (LGA) and neonatal hypoglycemia were 3.75 (95% CI: 1.97–7.12, P < 0.001) and 1.65 (95% CI: 0.79–3.43, P = 0.183), respectively. Also, the results of the 50-g GCT for each category showed strong association with increased risks of adverse perinatal outcomes compared to the normal 50-g GCT group. The OR of macrosomia (up to 20.31-fold), LGA (up to 6.15-fold), and neonatal hypoglycemia (up to 84.00-fold) increased with increasing 50-g GCT result.

Brain–computer interfacing under distraction: an evaluation study

Objective. While motor-imagery based brain–computer interfaces (BCIs) have been studied over many years by now, most of these studies have taken place in controlled lab settings. Bringing BCI technology into everyday life is still one of the main challenges in this field of research. Approach. This paper systematically investigates BCI performance under 6 types of distractions that mimic out-of-lab environments. Main results. We report results of 16 participants and show that the performance of the standard common spatial patterns (CSP) + regularized linear discriminant analysis classification pipeline drops significantly in this ‘simulated’ out-of-lab setting. We then investigate three methods for improving the performance: (1) artifact removal, (2) ensemble classification, and (3) a 2-step classification approach. While artifact removal does not enhance the BCI performance significantly, both ensemble classification and the 2-step classification combined with CSP significantly improve the performance compared to the standard procedure. Significance. Systematically analyzing out-of-lab scenarios is crucial when bringing BCI into everyday life. Algorithms must be adapted to overcome nonstationary environments in order to tackle real-world challenges.

Incorporating Spatial Information and Endmember Variability Into Unmixing Analyses to Improve Abundance Estimates.

Incorporating endmember variability and spatial information into spectral unmixing analyses is important for producing accurate abundance estimates. However, most methods do not incorporate endmember variability with spatial regularization. This paper proposes a novel 2-step unmixing approach, which incorporates endmember variability and spatial information. In step 1, a probability distribution representing abundances is estimated by spectral unmixing within a multi-task Gaussian process framework (SUGP). In step 2, spatial information is incorporated into the probability distribution derived by SUGP through an a priori distribution derived from a Markov random field (MRF). The proposed method (SUGP-MRF) is different to the existing unmixing methods because it incorporates endmember variability and spatial information at separate steps in the analysis and automatically estimates parameters controlling the balance between the data fit and spatial smoothness. The performance of SUGP-MRF is compared with the existing unmixing methods using synthetic imagery with precisely known abundances and real hyperspectral imagery of rock samples. Results show that SUGP-MRF outperforms the existing methods and improves the accuracy of abundance estimates by incorporating spatial information.

A Statistical Approach to Determine the Optimal Duration of Post-Treatment Follow-Up: Application to Metastatic Nonseminomatous Germ Cell Tumors

BackgroundThe objective of this study was to present a statistical method to define an optimal duration of follow-up for patients in remission after treatment for cancer, for detection of recurrences. Patients and MethodsSurveillance duration was estimated using the 2-step approach proposed by Mould et al. Relapse-free interval was modeled using the parametric cure model proposed by Boag. The optimal length of follow-up was then estimated as the minimal elapsed time after which the probability of a patient to relapse and to be cured with success is below a given threshold value. The method is applied to 2 real data sets of patients treated for metastatic non seminomatous germ-cell tumors: T93BP and T93MP. ResultsFor the T93BP, cure rate was estimated at 91.3% and proportions of patients who relapsed after 3 and 5 years were estimated at 0.5% and 0.2%. With a probability of success of salvage treatment equal to 80% and 50%, numbers of delayed cases after 5 years were 2 and 1. For T93MP, the proportion of patients who presented relapse after 5 and 10 years were estimated at 5.2% and 2.6%. Considering a probability of salvage treatment equal to 20%, the number of delayed cases after 5 and 10 years were 10 and 5. ConclusionUsing this methodology, duration of post-therapeutic follow-up might be tailored according to an objective criteria: the number of patients who present relapse after the end of follow-up and who could have been treated with success in case of early detection.

Factors affecting lactoferrin concentration in human milk: how much do we know?

Lactoferrin (LF) is a breast milk glycoprotein with antimicrobial and anti-inflammatory effects. Its beneficial properties in infants, especially in those born preterm, are currently being studied in clinical trials. However, the maternal and nursing infant factors that may affect LF concentration in breast milk are still not clear. We conducted a systematic review to investigate the factors that may affect the concentration of LF in breast milk. We used a 2-step approach to identify the eligible studies according to inclusion/exclusion criteria, and to determine which studies would be considered. We included 70 qualified articles from 29 countries with publication dates ranging from 1976 to 2015. We described the correlation between LF concentration in breast milk and lactation stage; 10 maternal factors, such as race, parity, among others; and 2 infant factors: infections and prematurity. Colostrum has the highest LF levels, but they decrease with days postpartum. No other factor has been consistently associated with LF concentration. A major limitation of the majority of the published studies is the small sample size and the different methods used to measure LF concentration. Therefore, there is a need for large, multicenter studies with standardized study design, sample collection, and LF measurement methods to identify clinically significant factors associated with LF expression in breast milk, which will help promote exclusive breastfeeding in preterm infants.

A granular approach to improve reproducibility of the echocardiographic assessment of paravalvular regurgitation after TAVI.

Paravalvular leak (PVL) after transcatheter aortic valve implantation (TAVI) is challenging to quantitate. Transthoracic echocardiography (TTE) is the main tool used for the assessment of PVL but is modestly reproducible. We sought to develop a reproducible echocardiographic approach to assess PVL in the post-TAVI setting. Four observers independently analyzed eleven parameters of PVL severity in 50 pre-discharge TTE studies performed after TAVI. The parameters included color-Doppler parameters [jet circumferential extent (CE) and planimetered vena contracta area in the short-axis view and jet breadth and qualitative features in the long-axis views], continuous-wave Doppler parameters [jet velocity time integral (VTI) and pressure half time (PHT)], quantitative Doppler parameters (regurgitation volume and fraction and effective regurgitant orifice area), aortic diastolic flow reversal and valve stent eccentricity. Intraclass correlation coefficient (ICC) and coefficient of variation (CV) for numerical parameters and kappa coefficient (κ) for categorical parameters were calculated for inter- and intra-observer comparisons. Inter-observer ICC was highest and CV lowest for CE (0.88 and 0.36), jet origin breadth (0.82 and 0.39), jet qualitative features in long-axis views (0.87 and 0.26), jet VTI (0.87 and 0.04) and PHT (0.73 and 0.10). Similar results were found in intra-observer comparisons. A 2-step granular approach combining the most reproducible parameters was used to grade PVL by the four observers. Inter-observer agreement was achieved in 86 % of cases (κ = 0.79). Combining color Doppler and continuous wave Doppler parameters in a granular algorithm yields excellent reproducibility of PVL assessment by TTE.Electronic supplementary materialThe online version of this article (doi:10.1007/s10554-016-0947-4) contains supplementary material, which is available to authorized users.

Detecting Gene-Environment Interactions for a Quantitative Trait in a Genome-Wide Association Study.

A genome-wide association study (GWAS) typically is focused on detecting marginal genetic effects. However, many complex traits are likely to be the result of the interplay of genes and environmental factors. These SNPs may have a weak marginal effect and thus unlikely to be detected from a scan of marginal effects, but may be detectable in a gene-environment (G×E) interaction analysis. However, a genome-wide interaction scan (GWIS) using a standard test of G×E interaction is known to have low power, particularly when one corrects for testing multiple SNPs. Two 2-step methods for GWIS have been previously proposed, aimed at improving efficiency by prioritizing SNPs most likely to be involved in a G×E interaction using a screening step. For a quantitative trait, these include a method that screens on marginal effects [Kooperberg and Leblanc, 2008] and a method that screens on variance heterogeneity by genotype [Paré etal., 2010] In this paper, we show that the Paré etal. approach has an inflated false-positive rate in the presence of an environmental marginal effect, and we propose an alternative that remains valid. We also propose a novel 2-step approach that combines the two screening approaches, and provide simulations demonstrating that the new method can outperform other GWIS approaches. Application of this method to a G × Hispanic-ethnicity scan for childhood lung function reveals a SNP near the MARCO locus that was not identified by previous marginal-effect scans.

Prognostic Importance of Diastolic Dysfunction in Relation to Post Procedural Aortic Insufficiency in Patients Undergoing Transcatheter Aortic Valve Replacement.

We sought to examine whether baseline diastolic dysfunction (DD) is associated with increased mortality in patients who develop aortic insufficiency (AI) after transcatheter aortic valve replacement (TAVR). Significant post-TAVR AI is associated with increased mortality, likely secondary to adverse hemodynamics secondary to volume overload and decreased LV compliance from chronic pressure overload. However, the effect of baseline DD on outcomes of patients with post-TAVR AI has not been studied. A total of 195 patients undergoing TAVR were included in the study. Patients with moderate-to-severe mitral stenosis, prior mitral valve replacement or atrial fibrillation were excluded. DD was classified at baseline by a 2-step approach as recommended by the American Society of Echocardiography while AI was evaluated 30 days post-TAVR. Follow up data up to 2 years post-TAVR was used in survival analysis. Patients with severe baseline DD who developed ≥mild post-TAVR AI had increased mortality compared to all other patients (HR = 3.89, CI: 1.76-8.6, P = 0.001), which remained significant after adjusting for post-TAVR AI, pre-TAVR AI, baseline mitral regurgitation, ejection fraction, pulmonary artery pressure, creatinine clearance and history of stroke. Even mild post-TAVR AI may have a negative impact on outcomes of patients with underlying severe DD. © 2016 Wiley Periodicals, Inc.

Perinatal outcomes after adopting 1- versus 2-step approach to diagnosing gestational diabetes

Objective: The American College of Obstetricians and Gynecologists (ACOG) and the IADPSG (International Association of Diabetes and Pregnancy Study Groups) proposed distinct approaches to diagnosing gestational diabetes mellitus (GDM). We sought to analyze these paradigms: (1) ACOG 2-step approach where screening is followed by diagnostic testing, (2) IADPSG 1-step diagnostic testing.Study design: We reviewed data from pregnant women (24–28 wks) screened for GDM over two periods: (1) November 2011–May 2012 (2) November 2012–May 2013. Period 1: 2-step approach (screening 1-h glucose challenge test (GCT) followed by a diagnostic 3-h 100-g glucose tolerance test (GTT) when abnormal (≥140 mg/dl)). Period 2: an abnormal value after a 2-h 75-g GTT result was diagnostic of GDM. We compared the incidence of GDM and perinatal outcomes using either approach.Results: Out of 471 patients screened by ACOG 2-step approach, 72 (15.3%) had an abnormal 1-h screening and underwent the 3-h diagnostic GTT, and 26 (5.5%) developed GDM. The 1-step approach resulted in 53 (15.96%) with GDM of a total 332 evaluated. There was no statistically significant difference in perinatal outcomes between the two cohorts. Maternal weight at the start and the end of pregnancy was greater for patients diagnosed by the ACOG 2-step approach.Conclusion: Adopting 1-step approach (ADA) to diagnose GDM resulted in a 3-fold increase in prevalence of GDM with no differences in perinatal outcomes.

Integrated Process and Plant Design Optimisation of Industrial Scale Batch Systems: Addressing the Inherent Dynamics through Stochastic and Hybrid Approaches

This work explores stochastic and hybrid solution approaches for dealing with the problem of integrated batch process development and plant design. The simultaneous optimization of batch process synthesis, task allocation and plant design has been formulated in the literature as a mixed-logic dynamic optimization (MLDO) problem, including dynamic control profiles, continuous variables, integers and Booleans as degrees of freedom. In industrial scale situations, this formulation leads to numerically intractable problems when mathematical programming solution strategies are used. So, this work presents a 2-step approach that combines a differential genetic algorithm (DGA) with a deterministic directsimultaneous solution that transforms the problem into a non-linear programming (NLP) problem. The core idea is to combine in the DGA chromosomes the multiple decisions that characterize the problem, and then to use the solution obtained for reducing the complexity of this highly non-linear problem, so it can be managed by standard deterministic solvers. A comparative study of the stochastic and hybrid strategies with the purely deterministic solution is made for the specific case of primary copolymerization for acrylic fibre production. The results show that local optimal solutions of the deterministic method can be beaten by the proposed optimization strategy, becoming a suitable option for solving cases of industrial size.

Evaluation of molecular and culture methods to determine the optimum testing strategy for verotoxigenic Escherichia coli in faecal specimens

We evaluated 5 methods for the detection of verotoxogenic Escherichia coli (VTEC) from faecal specimens to determine the most sensitive and specific method(s) and to advise an optimum testing strategy. A total of 681 stool specimens were examined using up to 5 diagnostic molecular and phenotypic methods that are used routinely in the VTEC Reference laboratory, Dublin. A testing strategy incorporating a 2-step approach that included a single Real Time-PCR and 1 culture-based method yielded the highest sensitivity, specificity, positive predictive value, and negative predictive value of 98.21%, 100%, 100%, and 99.43%, respectively.

Screening Performance for Frailty Among Older Patients With Cancer: A Cross-Sectional Observational Study of Two Approaches.

To investigate the screening performance for frailty of the Vulnerable Elders Survey-13 (VES-13) and the 2-step approach consisting of the VES-13 plus the anhedonia (loss of interest or pleasure) item from Patient Health Questionnaire-9 (PHQ-9) among older patients with newly diagnosed cancer. This study involved 106 consecutive inpatients aged 65 years or older, newly diagnosed with malignant lymphoma or multiple myeloma, just before chemotherapy initiation. The participants were administered the VES-13, and also underwent a comprehensive geriatric assessment (CGA), including for depression and 6 other geriatric conditions, using validated measures, just before initiation of chemotherapy. We defined frailty as the presence of 2 or more geriatric conditions as determined by the CGA. Receiver operating characteristic analysis was performed. The 2-step screening approach was examined by post hoc analysis. The average age of the subjects was 74 years. Among the 106 subjects, 50% met the criteria for frailty. Using a cutoff score of 2 to 3 on the VES-13, a sensitivity and negative predictive value (NPV) of 72% of the screening tool was obtained for the condition of frailty. When the second step of the screening, consisting of the VES-13 plus anhedonia, was applied to the VES-13-negative patients, the sensitivity and NPV improved to 90% and 88%, respectively. The 2-step approach exhibited better screening performance for frailty among patients with cancer than existing methods. Large prospective studies are required in the future to confirm this ability of the 2-step approach.

Descent of the fetal head (station) during the first stage of labor

High station at specific points in the first stage of labor, such as a floating head on admission, or at 4-cm dilation or when arrest of dilation occurs, is associated with higher rates of failure to deliver vaginally. Therefore it could be useful to know if station is within an expected range at a given dilation during first stage. Arrest of descent disorders have been defined thus far on criteria applicable in the second stage. Statistical modeling is an attractive methodology to characterize the relationship between station and dilation because the resulting mathematical expressions could be used as a reference for comparison in the future. In addition, they can be used to produce a finely graded assessment of descent using numerical terms such as percentile rankings. A 2-step approach to potentially improving the assessment of station could be to develop a statistical model that describes the general relationship between station and dilation in the first stage of uncomplicated births and then determine if such a model would have identified births with complications related to poor labor progress. Given the complex nature of labor data, especially the imprecision of dilation and station measurement, it is not immediately evident that such a model is identifiable or what its precision would be. We sought to characterize in mathematical terms the relationship of station to dilation during the first stage of labor for nulliparous and multiparous women with spontaneous vaginal births. This retrospective cohort study included 28,121 exams from 5555 women with singleton cephalic presentations at ≥37 weeks' gestation with electronic fetal monitoring tracings, who delivered vaginally without instrumentation and had 5-minute Apgar scores >6 at 2 academic community referral hospitals in 2012 through 2013. Women with a previous cesarean birth were excluded. We used longitudinal statistical techniques suitable to biological data that were irregularly sampled with repeated measures over time. A linear relationship was observed between station and dilation. For both nulliparous and multiparous women the final model was a linear regression with random effects for intercept and slope and a first-order autoregressive correlation structure. The 5th-95th range of station at any given dilation spanned about 3-4 cm. Our results demonstrate a general trend of increasing descent of the presenting part as dilation advances during the first stage of labor in women who delivered vaginally without instrumentation. We propose that the mathematical expressions describing this relationship may be valuable in the assessment of first-stage labor progression.