False-negative Outcome Research Articles

Meta-analytic review on the impact of factors that affect performance of malaria rapid diagnostic test in Africa

Timely, accurate diagnosis and treatment has improved malaria case management. Malaria Rapid Diagnostic Test (mRDT) kits are largely used in malaria diagnosis. Their performance is compromised by factors related to gene deletions, parasite density, quality of the kit, poor storage conditions and end-user inefficiencies hence diagnosis gives either positive, negative, false negative (FN) or false positive (FP) which defines consequent management strategies. This review assessed reports on prevalence of the Plasmodium falciparum histidine rich protein 2/3 (Pfhrp2/3) gene deletions in malaria infected populations in Africa and the risk of mRDT failure to identify malaria positive cases. Preferred Reporting Items for Systematic Meta-Analysis (PRISMA) statement was used for data collection. Literature search was done using Google and Mendel search for data published in a malaria journal, Journal of infectious diseases, scientific reports, Annals of Ibadan postgraduate medicine, and BMC journals published between 2019 and 2023. Fifty eight reports were identified were screened and tested for eligibility. 
 Majority of studies described the consistent use of Pfhrp2/3 mRDT for malaria diagnosis in rural health facilities in Africa and nine reports met inclusion criteria for review. Five of them certified the world health organization’s sample criteria of ‘more than 350 sample’ to estimate the prevalence of Pfhrp2/3 gene deletions leading to declaration of false negative results of which one study posted FN outcome resulting from these deletions. Four out of nine studies did not meet this WHO criterion. This review affirmed presence of Pfhrp2/3 gene deletions challenges in Africa though other countries recorded the converse. Data was pooled using random effect models with Odds ratio and 95% confidence limit. The prevalence of the gene deletions was heterogeneous, ranging from 0% to 78.1%. The review found that an average prevalence of Pfhrp2/3 deletion as 26.2%. This was above the WHO standard recommended declaration value of 5%.; a factor that demonstrated setback to the use of mRDT in malaria endemic regions. Therefore alternative methods should be used where aspersions are cast on outcome of mRDT for 
 it will help improve malaria treatment, tracking and management.

Eliciting and stop dose during oral food challenges for peanut and common tree nuts in different age groups.

Oral food challenges (OFCs) are used to confirm or reject a diagnosis of food allergy. However, younger children may encounter difficulties in consuming all offered doses during an OFC in the absence of symptoms, resulting in inconclusive outcomes. Our aim is to assess the eliciting dose for objective symptoms among various age groups and determine the necessity of consuming the final dose step during an uneventful OFC to avoid false negative outcomes. OFCs for common food allergens performed between 2012 and 2019 were analyzed retrospectively. The primary outcome was the association of age with stop dose for OFCs with inconclusive outcome. Secondary outcome measures were the association of age with eliciting dose and the potential number of false negative outcomes. A total of 1327 OFCs were performed in 707 patients. Of these, 514 (38.7%) were positive, 589 (44.4%) negative, and 224 (16.9%) inconclusive. In OFCs with inconclusive outcome, age appeared to be a significant predictor of the stop dose only for almond (p = .005). Objective symptoms occurred after the last dose step in 2%-13% of all OFCs with positive outcome. In our cohort, potential false negative outcomes may have been drawn in 27.6% of uneventful OFCs. Two third of children under 6 years of age successfully consumed all the provided doses during OFCs with a negative outcome. The eliciting dose for objective symptoms was not associated with age, and in a substantial number of OFCs with positive outcome, symptoms occurred after eating the final dose. These findings suggest that in case of an uneventful OFC, the outcome should be drawn only after a cumulative dose of 4.4 g has been consumed to avoid the risk of a potential false negative outcome.

Reducing False Negative Intrusions Rates of Ensemble Machine Learning Model based on Imbalanced Multiclass Datasets

In spite of the efforts to improve the efficiency of intrusion detection systems based on machine learning algorithms, these systems still need more. The false negative (FN) prediction outcome is of a major priority among other outcomes, when attacks are considered as normal by classifiers. FN outputs are highly a concern issue, especially for multiclass classification, where minor classes have less instances in imbalanced datasets. In this work, three types of well-known imbalanced multiclass classification datasets are used with ensemble machine learning classifiers. The datasets: KDD99, UNSW_NB15, and CICIDS2017 are balanced using different combination of oversampling and under-sampling techniques to improve false negative rates. Suitable performance metrics have been used to obtain significant outputs improvements in all three datasets types using Random Forest classifier. Achieved accuracies are 99.9852% for KDD99, 83.5451% for UNSW_NB15 and 99.8613% for CICIDS2017. The outcomes of the work using the mentioned datasets have been compared with state-of-the-art related works and the results show a clear improvement in false negative rates.

Donor-derived Cell-free DNA Measurement in Kidney Transplant Patients Without Allograft Dysfunction: More Evidence and More Questions.

Donor-derived Cell-free DNA Measurement in Kidney Transplant Patients Without Allograft Dysfunction: More Evidence and More Questions.

Shared Savings Model Risk in the MSSP Program

The Centers for Medicare and Medicaid Services (CMS) introduced the Medicare Shared Savings Program (MSSP) for accountable care organizations (ACOs) as part of the Affordable Care Act. Participating ACOs accept risk for the financial outcomes of their assigned populations and share in gains (and, depending on the ACO model, losses) when these are generated. Gains and losses are calculated by comparing actual costs of the ACO population against a benchmark cost based on the historical performance of members in the ACO. Participating ACOs are at risk of model error. Because of stochastic variance in cost distributions and the imperfect operation of the risk-adjustment process, there is a nontrivial probability that an ACO may experience a false positive (gains are calculated where no gains were actually generated) or false negative (a loss is calculated by the model when no losses were actually generated). Using a sample of Medicare fee-for-service data, we model outcomes for typical ACOs and for ACOs consisting of chronic patients. For a typical ACO, the probability of model error resulting in a false positive or false negative outcome is between 5% and 8%. Chronic populations with higher variance have higher probabilities of model error, between 26% and 28% for a diabetes population, and about 23% for a cancer population. In the case of an ACO that generates gains through increased efficiency, model error can result in the ACO failing to realize gains, or even (in a minority of cases) require a reimbursement to the payer. From the perspective of the payer with a number of ACOs, the average overpayment or recovery will be minor. The percentage overpayment (recovery) increases as the prevalence of chronic patients increases. For a population of cancer patients a payer can expect to pay (or recover) between 1.0% and 2.0% of claims, while for a diabetes population the range is 1.5–2.5%. For an individual ACO the loss or gain is more significant because the ACO gains or loses the full amount, with a relatively high probability. While this study has focused on the Medicare Shared Savings Program, the MSSP is just an example of a class of gainsharing models that is increasingly prevalent in value-based contracts. Payers and providers who negotiate value-based contracts need to be aware of and account for model risk in their contracts, particularly as the sizes of populations under management become smaller.

Transcriptional Profiling and Machine Learning Unveil a Concordant Biosignature of Type I Interferon-Inducible Host Response Across Nasal Swab and Pulmonary Tissue for COVID-19 Diagnosis.

BackgroundCOVID-19, caused by SARS-CoV-2 virus, is a global pandemic with high mortality and morbidity. Limited diagnostic methods hampered the infection control. Since the direct detection of virus mainly by RT-PCR may cause false-negative outcome, host response-dependent testing may serve as a complementary approach for improving COVID-19 diagnosis.ObjectiveOur study discovered a highly-preserved transcriptional profile of Type I interferon (IFN-I)-dependent genes for COVID-19 complementary diagnosis.MethodsComputational language R-dependent machine learning was adopted for mining highly-conserved transcriptional profile (RNA-sequencing) across heterogeneous samples infected by SARS-CoV-2 and other respiratory infections. The transcriptomics/high-throughput sequencing data were retrieved from NCBI-GEO datasets (GSE32155, GSE147507, GSE150316, GSE162835, GSE163151, GSE171668, GSE182569). Mathematical approaches for homological analysis were as follows: adjusted rand index-related similarity analysis, geometric and multi-dimensional data interpretation, UpsetR, t-distributed Stochastic Neighbor Embedding (t-SNE), and Weighted Gene Co-expression Network Analysis (WGCNA). Besides, Interferome Database was used for predicting the transcriptional factors possessing IFN-I promoter-binding sites to the key IFN-I genes for COVID-19 diagnosis.ResultsIn this study, we identified a highly-preserved gene module between SARS-CoV-2 infected nasal swab and postmortem lung tissue regulating IFN-I signaling for COVID-19 complementary diagnosis, in which the following 14 IFN-I-stimulated genes are highly-conserved, including BST2, IFIT1, IFIT2, IFIT3, IFITM1, ISG15, MX1, MX2, OAS1, OAS2, OAS3, OASL, RSAD2, and STAT1. The stratified severity of COVID-19 may also be identified by the transcriptional level of these 14 IFN-I genes.ConclusionUsing transcriptional and computational analysis on RNA-seq data retrieved from NCBI-GEO, we identified a highly-preserved 14-gene transcriptional profile regulating IFN-I signaling in nasal swab and postmortem lung tissue infected by SARS-CoV-2. Such a conserved biosignature involved in IFN-I-related host response may be leveraged for COVID-19 diagnosis.

Accuracy of caregiver identification of demands for children with escape-maintained challenging behavior

BackgroundAlthough stimulus preference assessments are widely used to identify reinforcers and to inform positive reinforcement conditions in a functional analysis (FA), direct assessments of potential negative reinforcers are not as commonly employed. Demands are often selected from caregiver report alone. AimsThe purpose of the current study is to (a) replicate the Demand Assessment for Individuals with Severe Disabilities (DAISD) indirect assessment interview for caregivers to identify demands that may evoke challenging behavior; (b), compare the correspondence of the DAISD in relation to an established direct assessment, the demand latency assessment (DLA); and (c) evaluate if the demands that caregivers identify as the most aversive are more likely to evoke challenging behavior and identify an escape function in an FA than those demands caregivers identify as least aversive and replicate validation of the DLA. Methods and proceduresThis study evaluated caregiver accuracy at identifying demands most likely to evoke escape-maintained challenging behavior for four children with developmental disabilities. Caregiver-informed aversiveness hierarchies from the DAISD were compared to child-informed aversiveness hierarchies from the DLA. Functional analyses included separate escape conditions with DAISD and DLA most and least aversive demands. Outcomes and resultsAlthough all caregivers identified at least eight demands, caregivers’ accuracy with demand aversiveness was variable as indicated by (a) a false negative FA outcome for one of four participants with the caregiver-nominated most aversive demand; (b) higher rates of challenging behavior with the caregiver-nominated least aversive demand than most aversive for three of four participants; and (c) lack of a strong positive rank order correlation between caregiver- and child-hierarchies for all participants (range, −0.76 to .48). Compliance was not a strong predictive variable of challenging behavior with either assessment. Conclusions and implicationsResults indicate that the DAISD interview is useful at identifying multiple demands presented in the natural environment, but should be followed up with direct assessment to determine demand aversiveness rather than used for caregivers to rank demand aversiveness.

EEG Patterns and Outcomes After Hypoxic Brain Injury: A Systematic Review and Meta-analysis.

Electroencephalography (EEG) is used to prognosticate recovery in comatose patients with hypoxic ischemic brain injury (HIBI) secondary to cardiac arrest. We sought to determine the prognostic use of specific EEG patterns for predicting disability and death following HIBI secondary to cardiac arrest. This systematic review searched Medline, Embase, and Cochrane Central up to January 2020. We included original research involving prospective and retrospective cohort studies relating specific EEG patterns to disability and death in comatose adult patients suffering HIBI post cardiac arrest requiring admission to an intensive care setting. We evaluated study quality using the Quality of Diagnostic Accuracy Studies 2 tool. Descriptive statistics were used to summarize study, patient, and EEG characteristics. We pooled study-level estimates of sensitivity and specificity for EEG patterns defined a priori using a random effect bivariate and univariate meta-analysis when appropriate. Funnel plots were used to assess publication bias. Of 5191 abstracts, 333 were reviewed in full text, of which 57 were included in the systematic review and 32 in meta-analyses. No reported EEG pattern was found to be invariably associated with death or disability across all studies. Pooled specificities of status epilepticus, burst suppression, and electrocerebral silence were high (92-99%), but sensitivities were low (6-39%) when predicting a composite outcome of disability and death. Study quality varied depending on domain; patient flow and timing performed was well conducted in all, whereas EEG interpretation was retrospective in 17 of 39 studies. Accounting for variable study quality, EEG demonstrates high specificity with a low risk of false negative outcome attribution for disability and death when status epilepticus, burst suppression, or electrocerebral silence is detected. Increased use of standardized cross-study protocols and definitions of EEG patterns are required to better evaluate the prognostic use of EEG for comatose patients with HIBI following cardiac arrest.

Abstract 467: Detecting ALK rearrangement by RT-PCR: A superior approach to next generation sequencing

Abstract Background: Precisely detecting anaplastic lymphoma kinase (ALK) rearrangement ensures ideal efficacy of ALK targeted tyrosine kinase inhibitors (ALK-TKIs). Next generation sequencing (NGS) has been widely used in clinics, while, numbers of studies indicated NGS would yield false negative outcome, especially for fusion analysis. Instead, more fusions can be detected by RT-PCR at transcription level. This study aims to compare the capacity of RT-PCR and NGS approach to detect ALK rearrangement in Chinese non-small-cell lung cancer (NSCLC) patients. Methods: Formalin-fixed paraffin-embedded (FFPE) tissues from 153 patients pathologically diagnosed as NSCLC with eligible ALK status given by previous NGS testing (29 patients were ALK positive and 124 patients were ALK negative) were collected from November 2017 to October 2019. RT-PCR were applied to detect ALK rearrangements in both groups. For samples with discordant result of ALK status, fluorescence in situ hybridization (FISH) or Sanger's sequencing were used for validation. Results: One hundred and twenty-four samples (26 of 30 ALK positive samples; 98 of 124 ALK negative samples) were successfully subjected to RT-PCR. Five of 98 ALK negative samples given by NGS test were re-defined as ALK positive by RT-PCR. Meanwhile, in 26 ALK positive samples, RT- PCR yielded acceptable result with 96.15% of concordance rate. Only one NGS-defined ALK positive sample was uncovered by RT-PCR due to a rare ALK rearrangement. Four of 6 RT-PCR defined ALK positive cases (3 RT-PCR positive and 1 NGS positive) were validated by either FISH or sanger's sequencing, which resulted positive result. Conclusions: RT-PCR displays reliable and superior capacity to detect ALK fusion in NSCLC patients. Citation Format: Yukun Kuang, Peihang Xu, Jiyu Wang, Yifan Zheng, Xue Sun, Zimu Li, RunJing Gan, Huixia Li, Yubiao Guo, Guanshan Zhu, Changbin Zhu, Zunfu Ke, Kejing Tang. Detecting ALK rearrangement by RT-PCR: A superior approach to next generation sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 467.

Ultrasound guided airway assessment- an observational study to correlate airway parameter to cormack-lehane grading of laryngoscopy

Securing airway is an important routine for any Anesthesiologist. Assessment of airway preoperatively is an essential part of predicting difficulty in airway management. Mallampati test (MP) is commonly applied during such preoperative assessments. However, Mallampati test is an indirect clinical sign in which thickness of the base of the tongue is assessed by whether it masks faucial pillar (palatoglossal and palatopharyngeal arches) or not. Though MP is an indirect assessment, this test is routinely applied because of ease of applying this test. This test however is not completely reliable in predicting difficulty in laryngoscopy and intubation and has high false-positive and false-negative outcome. The depth of floor of the mouth and thickness of tongue can be assessed to improve prediction of difficult airway. This depth can be measured by cheap and rapid test using ultrasonography. In this study depth of the tissues in the floor of the mouth were measured by placing USG probe above hyoid bone in sagittal plane and measurement taken from skin to mucous membrane of tongue and attempted to establish any relationship between this thickness and difficulty in laryngoscopy as assessed by Cormack-Lehanne scoring.60 ASA I & II patients undergoing elective surgeries under GA were assessed during the pre-anaesthetic evaluation and supra-hyoid USG depth in sagittal plane was measured and recorded. During laryngoscopy Cormack and Lehanne scoring was recorded for each of the subjects by 2 experienced anaesthesiologists who were blinded to the depth assessment.

What Factors Influence Non-Participation Most in Colorectal Cancer Screening? A Discrete Choice Experiment.

Background and ObjectiveNon-participation in colorectal cancer (CRC) screening needs to be decreased to achieve its full potential as a public health strategy. To facilitate successful implementation of CRC screening towards unscreened individuals, this study aimed to quantify the impact of screening and individual characteristics on non-participation in CRC screening.MethodsAn online discrete choice experiment partly based on qualitative research was used among 406 representatives of the Dutch general population aged 55–75 years. In the discrete choice experiment, respondents were offered a series of choices between CRC screening scenarios that differed on five characteristics: effectiveness of the faecal immunochemical screening test, risk of a false-negative outcome, test frequency, waiting time for faecal immunochemical screening test results and waiting time for a colonoscopy follow-up test. The discrete choice experiment data were analysed in a systematic manner using random-utility-maximisation choice processes with scale and/or preference heterogeneity (based on 15 individual characteristics) and/or random intercepts.ResultsScreening characteristics proved to influence non-participation in CRC screening (21.7–28.0% non-participation rate), but an individual’s characteristics had an even higher impact on CRC screening non-participation (8.4–75.5% non-participation rate); particularly the individual’s attitude towards CRC screening followed by whether the individual had participated in a cancer screening programme before, the decision style of the individual and the educational level of the individual. Our findings provided a high degree of confidence in the internal–external validity.ConclusionsThis study showed that although screening characteristics proved to influence non-participation in CRC screening, a respondent’s characteristics had a much higher impact on CRC screening non-participation. Policy makers and physicians can use our study insights to improve and tailor their communication plans regarding (CRC) screening for unscreened individuals.

A state-wide population-based evaluation of cervical cancers arising during opportunistic screening in the United States

ObjectiveDespite widespread cervical screening, an estimated 13,800 women will be diagnosed with cervical cancer in the United States in 2020. To inform improvements, the screening histories of women diagnosed with cervical cancer in New Mexico were assessed. MethodsData were collected on all cervical screening, diagnostic tests and treatment procedures for all women diagnosed with cervical cancer aged 25-64 yrs. in New Mexico from 2006 to 2016. Women were categorized by their screening attendance in the 5–40 months (screening interval) and 1–4 months (peri-diagnostic interval) prior to cancer diagnosis. ResultsOf the 504 women diagnosed between May 2009–December 2016, 64% were not screened or had only inadequate screening tests in the 5–40 months prior to diagnosis, and 90 of 182 screened women (49%) had only negative screens in this period. Only 32% (N = 162) of cervical cancers were screen-detected. Women with adenocarcinomas were more likely to have had a recent negative screen (41/57 = 72%) than women with squamous cancers (50/112 = 45%). Both older women (aged 45–64 years) and women with more advanced cancers were less likely to have been screened, and if screened, were more likely to have a false-negative outcome. Only 9% of cancers were diagnosed in women who did not attend biopsy or treatment after positive tests requiring clinical management. Screening currently prevents 35% of cancers, whereas full screening coverage could prevent 61% of cervical cancers. ConclusionImproved screening coverage has the largest potential for reducing cervical cancer incidence, though there is also a role for improved recall procedures and screening sensitivity.

Considerations for Stress Testing Performed in Conjunction with Myocardial Perfusion Imaging.

For myocardial perfusion imaging (MPI), the best test to evaluate hemodynamic changes during stress is an exercise treadmill test. It provides independent prognostic value, including evaluation of total exercise time, performance, and capacity; heart rate response during exercise, with ischemia, and in recovery; blood pressure response; myocardial oxygen demand; and assessment of symptoms. Combining these exercise data with perfusion imaging provides the best prognostic value and risk stratification for patients. Although exercise stress testing accompanied by MPI is preferential, it is not always possible since an increasing number of patients cannot exercise to a maximal (symptom-limited) level. Further, there is much evidence in the literature demonstrating a suboptimal, non-symptom-limited (not achieving at least 4-6 min or <85% of maximum predicted heart rate) exercise test performed as part of an MPI study may result in a false-negative outcome. Therefore, pharmacologic stress agents provide an excellent alternative for those patients who cannot achieve an adequate heart rate response or adequately perform physical exercise. This article focuses on considerations for performing stress (exercise and pharmacologic) testing in conjunction with MPI. It is meant to provide a basic overview of the principles of exercise stress testing; discuss the indications, contraindications, patient preparation, and protocols for exercise stress testing; discuss the contraindications, administration protocols, and side effects for vasodilator (adenosine, dipyridamole, and regadenoson) stress testing; and discuss the contraindications, administration protocols, and side effects for dobutamine stress testing.

Relationship between somatic cell counts and subclinical mastitis in lactating dairy cows.

Background and Aim:Subclinical mastitis (SCM) is one of the most prevalent diseases of dairy cows, and somatic cell count (SCC) is widely used to determine SCM and milk quality. However, setting the threshold of SCC is very important. This study aimed to determine the cow-level threshold of SCC to differentiate milk of SCM affected cows from normal milk in Bangladesh.Materials and Methods:Sensitivity (Se) and specificity (Sp) along with other characteristics of different thresholds of SCC were determined considering the bacterial culture as the gold standard test. Three definitions of intramammary infection (IMI) were set based on the group of pathogens involved. Five categories of SCC thresholds were considered for analysis.Results:Se and Sp of thresholds of SCC greatly varied as definitions of IMI changed. Irrespective of SCC thresholds, Se increased when isolation of major pathogens included in IMI definitions. Se decreased when SCC thresholds increased (from 100 to 300 × 103 cells/mL) for all IMI definitions and ranged from 60.6% to 20.3%. The highest Se was found at low SCC threshold (100 × 103 cells/mL), which resulted in less false-negative outcome. On the other hand, Sp increased with the increment of SCC thresholds giving rise to a less false-positive outcome.Conclusion:The cow-level SCC threshold of 100 × 103 cells/mL was found appropriate to identify subclinical IMI of dairy cows.

Ultrasound Guided Biopsy in Suspicious Nonpalpable Breast Masses with Histopathological Correlation

Purpose: to evaluate the accuracy of ultra sound guided tru –cut biopsy in non palbable suspicious breast lesions and correlate with pathological results. Introduction: Tru-cut biopsy may be a exact elective will fine needle desire cytology (FNAC) in the finding for breast lesions for a helter skelter symptomatic exactness Similarly as it supplies sufficient tissue to pathologists to create a right histological appraisal. Currently it is those main favored methodology for the finding about breast lesions former should operation rendering should its low cost, secondary accuracy, negligible complications, safe and short duration of the time system. Additionally it might save a considerable measure about liabilities Also unnecessary surgical methods likewise lessens the affinity of muddled surgical methods Also minimizes tolerant anxiety with considerate lesions. Done patients for threatening lesions, What's more should Hosting symptomatic significance, TCB additionally gives sufficient tissue for the assessment from claiming atomic markers which need amazing restorative esteem. Patients and methods: This prospective, controlled ponder selected 40 female patients with non-palpable breast massenet undergone ultimo heartless guided biopsy (USGB) What's more excisional breast biopsy. Post-operative obsessive examination of the example required been directed to guarantee precision for tru-cut biopsy. Results: Special case patient of the instances required false negative outcome about tru-cut biopsy in examination for post-operative excisional biopsy. Conclusion:Ultimo heartless guided biopsy (USGB) may be vital done finding suspicious non palbable breast massenet that guarantee secondary precision outcomes.

HLA-DQ:gluten tetramer test in blood gives better detection of coeliac patients than biopsy after 14-day gluten challenge

ObjectiveInitiation of a gluten-free diet without proper diagnostic work-up of coeliac disease is a frequent and demanding problem. Recent diagnostic guidelines suggest a gluten challenge of at least 14 days...

Minimizing Probate-Error Risk

Probate-error risk is the possibility that a court will incorrectly assess the authenticity of a will. By prescribing the method courts use to evaluate the authenticity of wills, the law of will-execution allocates probate-error risk between false-positive outcomes and false-negative outcomes. When a court validates an inauthentic will, it creates a false-positive outcome. When a court invalidates an authentic will, it creates a false-negative outcome. Because false-positive outcomes result in the admission to probate of inauthentic wills and false-negative outcomes result in the denial of probate of genuine wills, both can be characterized as probate errors. This framework has been used to identify the problem with the conventional law of will-execution, which is that it generates unnecessary probate errors by heavily allocating risk in favor of false-negative outcomes. It has also clarified the objective of will-execution reform, which is to reallocate risk more evenly between false-positive outcomes and false-negative outcomes so that the total number of probate errors is minimized. This Article applies this framework more broadly to analyze potential methods of will-execution reform. Specifically, this Article identifies the various components of the law of will-execution that can be altered to reallocate probate-error risk and evaluates how different methods of reform can be manipulated to reallocate risk to varying degrees. With a better understanding of what is possible, state policymakers may be more willing to break away from the conventional law and implement change.

A probability tree model of audit quality

Abstract There remains little consensus about how to define and formulate audit quality. It does not have a consistent definition and operationalization across studies and this has troubled theorists for many years. This study contributes to this discussion by introducing a probability tree model of audit quality. This model is built up of characteristics to create an association with the four sets of audit quality indicators; inputs, process, context, and outcomes (Knechel, W. R, Krishnan, G. V., Pevzner, M., Shefchik, L. B., & Velury, U. (2012). Audit quality: Insights from the academic literature. Auditing: A Journal of Practice & Theory 32(1), 385–421). The purpose is to show how these indicators interplay in the context of audit quality. The model describes the audit program of an audit engagement as a random tree model based on a stochastic process. Following Simon's (Simon, H. A. (1956). Rational choice and the structure of the environment. Psychological Review 63(2), 129–138; Simon, H. A. (1957). Models of man. Social and rational. New York: John Wiley & Sons) description of adaptive behavior the model describes an audit program as an organic procedure where an auditor does not maximize but is seeking for material misstatements (inadvertent errors) in a random environment. If the auditor under a budget constraint does not (in spite of positive inherent risk) detect any misstatement, the audit program will erroneously end with an unqualified report (false negative outcome). In this context, we measure subjective audit quality as the probability of the complement of this event (probability of detecting one or more misstatements). We also introduce a concept of perfect auditor with optimal characteristics. Finally, we measure objective audit quality as the relation of the complement event probabilities between the auditor and the perfect auditor. The analytical results are demonstrated by numerical examples.

Intraoperative neurophysiological monitoring during resection of intradural extramedullary spinal cord tumors: experience with 100 cases.

Intradural-extramedullary spinal cord tumor surgery is common. Unlike intramedullary spinal cord tumor surgery, where intraoperative neurophysiological monitoring (IONM) has been described extensively, the application of IONM has not been described in this context, and its relevance has not been investigated. From 2001 to 2012, 100 patients underwent intradural-extramedullary spinal cord tumor resection with IONM. Preoperative and postoperative clinical evaluations were completed retrospectively, using a modified McCormick grading scale and correlated with IONM monitorability and dynamics. IONM consisted of transcranial motor evoked potentials (tcMEP), spinal (D wave) and muscle generators, somatosensory evoked potentials (SSEP), and electromyography (EMG). Both short-term and long-term clinical evaluations were performed. Patient demographics, tumor type, span, location, and morphologic complexity were analyzed. Surgeries were performed for resection of schwannomas (33 %), meningiomas (22 %), ependymomas (12 %), and other pathologies (20 %); pathology was unknown in 13 % of patients. Tumor locations were cervical in 21 %, thoracic in 46 %, thoracolumbar in 7 %, lumbar 20 %, and not specified in 6 %. Tumors spanned an average of 2.2 spinal levels. Monitorability was 97 and 67 % with tcMEP and SSEP modalities respectively. D waves were monitorable in 73 % of attempts. Intraoperative tcMEP changes were reported in 29 cases with 14 resolved intraoperatively, There were one false-negative outcome and five true-positive outcomes. For SSEP, 13 changes were noted and three resolved; there were three false-negative results and one true-positive result. For D wave monitoring there were two intraoperative changes with none resolved leading to one false negative and one true positive result. With a multimodality approach incorporating any change in evoked potential, IONM demonstrated sensitivity of 0.82, specificity of 0.95, positive predictive value of 0.82, and a negative predictive value of 0.95. IONM is feasible and useful in the context of intradural-extramedullary spinal cord surgery for identifying iatrogenic injury to the spinal cord.

Is off-frequency overshoot caused by adaptation of suppression?

This study is concerned with the mechanism of off-frequency overshoot. Overshoot refers to the phenomenon whereby a brief signal presented at the onset of a masker is easier to detect when the masker is preceded by a “precursor” sound (which is often the same as the masker). Overshoot is most prominent when the masker and precursor have a different frequency than the signal (henceforth referred to as “off-frequency overshoot”). It has been suggested that off-frequency overshoot is based on a similar mechanism as “enhancement,” which refers to the perceptual pop-out of a signal after presentation of a precursor that contains a spectral notch at the signal frequency; both have been proposed to be caused by a reduction in the suppressive masking of the signal as a result of the adaptive effect of the precursor (“adaptation of suppression”). In this study, we measured overshoot, suppression, and adaptation of suppression for a 4-kHz sinusoidal signal and a 4.75-kHz sinusoidal masker and precursor, using the same set of participants. We show that, while the precursor yielded strong overshoot and the masker produced strong suppression, the precursor did not appear to cause any reduction (adaptation) of suppression. Predictions based on an established model of the cochlear input–output function indicate that our failure to obtain any adaptation of suppression is unlikely to represent a false negative outcome. Our results indicate that off-frequency overshoot and enhancement are likely caused by different mechanisms. We argue that overshoot may be due to higher-order perceptual factors such as transient masking or attentional diversion, whereas enhancement may be based on mechanisms similar to those that generate the Zwicker tone.