Note: This page contains sample records for the topic apparent false negative from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

A Closer Look at Self-Reported Suicide Attempts: False Positives and False Negatives  

ERIC Educational Resources Information Center

The validity of self-reported suicide attempt information is undermined by false positives (e.g., incidences without intent to die), or by unreported suicide attempts, referred to as false negatives. In a sample of 1,385 Austrian adults, we explored the occurrence of false positives and false negatives with detailed, probing questions. Removing…

Ploderl, Martin; Kralovec, Karl; Yazdi, Kurosch; Fartacek, Reinhold

2011-01-01

2

On False-Positive and False-Negative Decisions with a Mastery Test.  

ERIC Educational Resources Information Center

Methods are described for obtaining upper and lower bounds to both false-positive and false-negative decisions with a mastery test. These methods make no assumptions about the form of the true score distribution. (CTM)

Wilcox, Rand R.

1979-01-01

3

Generalized site occupancy models allowing for false positive and false negative errors.  

PubMed

Site occupancy models have been developed that allow for imperfect species detection or "false negative" observations. Such models have become widely adopted in surveys of many taxa. The most fundamental assumption underlying these models is that "false positive" errors are not possible. That is, one cannot detect a species where it does not occur. However, such errors are possible in many sampling situations for a number of reasons, and even low false positive error rates can induce extreme bias in estimates of site occupancy when they are not accounted for. In this paper, we develop a model for site occupancy that allows for both false negative and false positive error rates. This model can be represented as a two-component finite mixture model and can be easily fitted using freely available software. We provide an analysis of avian survey data using the proposed model and present results of a brief simulation study evaluating the performance of the maximum-likelihood estimator and the naive estimator in the presence of false positive errors. PMID:16676527

Royle, J Andrew; Link, William A

2006-04-01

4

"False Positive" Claims of Near-Death Experiences and "False Negative" Denials of Near-Death Experiences  

ERIC Educational Resources Information Center

Some persons who claim to have had near-death experiences (NDEs) fail research criteria for having had NDEs ("false positives"); others who deny having had NDEs do meet research criteria for having had NDEs ("false negatives"). The author evaluated false positive claims and false negative denials in an organization that promotes near-death…

Greyson, Bruce

2005-01-01

5

False-negative appendicitis at ultrasound: nature and association.  

PubMed

The objective was to describe nature and factors associated with false-negative ultrasound (US) for adult appendicitis. Patients with pathologically proven appendicitis and pre-operative US from January 2011 to May 2013 were included in this retrospective case-control study. They were divided into true-positive and false-negative groups, matched by age and gender. There were 112 patients (40 men, mean age = 40 y, 56 true positives) included. Two factors were found differ significantly: abdominal wall thickness and pain score. Greater abdominal wall thickness (18.6 mm vs. 14.9 mm, p = 0.001) and lower pain score (6.6 vs. 7.5, p = 0.018) were statistically associated with false negativity. The two groups did not differ significantly in terms of weight, height, body mass index, symptom duration, Alvarado score, US examination time, appendix position/size, perforation rate and operator. In conclusion, lower pain score and increased abdominal wall thickness are associated with false negativity in US examinations. PMID:24768483

Piyarom, Patwadee; Kaewlai, Rathachai

2014-07-01

6

Balancing false positives and false negatives for the detection of differential expression in malignancies  

PubMed Central

A basic problem of microarray data analysis is to identify genes whose expression is affected by the distinction between malignancies with different properties. These genes are said to be differentially expressed. Differential expression can be detected by selecting the genes with P-values (derived using an appropriate hypothesis test) below a certain rejection level. This selection, however, is not possible without accepting some false positives and negatives since the two sets of P-values, associated with the genes whose expression is and is not affected by the distinction between the different malignancies, overlap. We describe a procedure for the study of differential expression in microarray data based on receiver-operating characteristic curves. This approach can be useful to select a rejection level that balances the number of false positives and negatives and to assess the degree of overlap between the two sets of P-values. Since this degree of overlap characterises the balance that can be reached between the number of false positives and negatives, this quantity can be seen as a quality measure of microarray data with respect to the detection of differential expression. As an example, we apply our method to data sets studying acute leukaemia.

De Smet, F; Moreau, Y; Engelen, K; Timmerman, D; Vergote, I; De Moor, B

2004-01-01

7

Damage to the Drosophila follicle cell epithelium produces "false clones" with apparent polarity phenotypes  

PubMed Central

Summary The Drosophila follicular epithelium, which surrounds developing egg chambers, is a well-established model for studying epithelial polarity because it is continuously generated from adult stem cells, making it easy to generate homozygous mutant clones in a heterozygous background. Mutant clones are usually marked by the loss of Green Fluorescent Protein (GFP) expression, which distinguishes them from their green, wild-type neighbours. Here we report that damage to the epithelium during dissection can produce groups of GFP-negative cells that resemble mutant clones. Furthermore, several polarity factors, such as aPKC and Discs large, are not localised in these damage-induced false clones. This phenotype is identical to that reported for several mutants, including ampk and Dystroglycan mutant clones under conditions of energetic stress. Using more reliable systems to mark ampk and Dystroglycan null clones such as the MARCM system, we found that neither protein is required for epithelial polarity under low energy conditions. Thus, our previous report of a specific low energy polarity pathway is an artefact of the increased damage caused by dissecting the small ovaries of starved flies. However, ampk mutant cells are larger than normal under both starvation and well-fed conditions, indicating that AMPK restricts follicle cell growth even when dietary sugar is not limiting. We suspect that several other reports of mutants that disrupt follicle cell polarity may also be based on the phenotype of damage-induced false clones, and recommend the use of positively marked clones to avoid this potential artefact.

Haack, Timm; Bergstralh, Dan T.; St Johnston, Daniel

2013-01-01

8

Damage to the Drosophila follicle cell epithelium produces "false clones" with apparent polarity phenotypes.  

PubMed

The Drosophila follicular epithelium, which surrounds developing egg chambers, is a well-established model for studying epithelial polarity because it is continuously generated from adult stem cells, making it easy to generate homozygous mutant clones in a heterozygous background. Mutant clones are usually marked by the loss of Green Fluorescent Protein (GFP) expression, which distinguishes them from their green, wild-type neighbours. Here we report that damage to the epithelium during dissection can produce groups of GFP-negative cells that resemble mutant clones. Furthermore, several polarity factors, such as aPKC and Discs large, are not localised in these damage-induced false clones. This phenotype is identical to that reported for several mutants, including ampk and Dystroglycan mutant clones under conditions of energetic stress. Using more reliable systems to mark ampk and Dystroglycan null clones such as the MARCM system, we found that neither protein is required for epithelial polarity under low energy conditions. Thus, our previous report of a specific low energy polarity pathway is an artefact of the increased damage caused by dissecting the small ovaries of starved flies. However, ampk mutant cells are larger than normal under both starvation and well-fed conditions, indicating that AMPK restricts follicle cell growth even when dietary sugar is not limiting. We suspect that several other reports of mutants that disrupt follicle cell polarity may also be based on the phenotype of damage-induced false clones, and recommend the use of positively marked clones to avoid this potential artefact. PMID:24337115

Haack, Timm; Bergstralh, Dan T; St Johnston, Daniel

2013-01-01

9

Apparent Negative Interference Due to Variation in Recombination Frequencies  

PubMed Central

Variation in recombination frequencies may lead to a bias in the estimated interference value in a linkage experiment. Depending on the pattern of variation, the bias may be toward negative interference or toward positive interference, even when there is positive interference at the cytological level. In this paper we have mainly concentrated on the case of negative interference. We use models to quantify this effect when data are derived from a backcross experiment or from the selfing of F(1) individuals. The effect is quantitatively similar in the two cases. There is an upper limit to the size the bias may reach for every given level of recombination. Two reported cases of negative interference in Drosophila and cultivated barley fall within this possible parameter range, i.e., the observed negative interference values could--at least in principle--be due solely to a variation in the recombination frequencies in the experiments.

Sall, T.; Bengtsson, B. O.

1989-01-01

10

Home pregnancy testing kits: prevalence of use, false-negative rates, and compliance with instructions.  

PubMed Central

This study investigated the prevalence of home pregnancy kit use, incidence of false-negative results, and compliance with testing procedures. Among 144 pregnant women, identified through three health care settings, prevalence of test-kit use was 28.5 per cent. The false-negative rate was 24.3 per cent. Total compliance with instructions was reported by only 32 per cent of users. Women testing less than nine days after menstrual period was due had false-negative rates of 33 per cent contrasted with 21 per cent for those testing after the nine days.

Valanis, B G; Perlman, C S

1982-01-01

11

False-negative results of breast core needle biopsies - retrospective analysis of 988 biopsies  

PubMed Central

Summary Background: Breast cancer is the most common malignant neoplasm and the most common cause of death among women. The core needle biopsy is becoming a universal practice in diagnosing breast lesions suspected of malignancy. Unfortunately, breast core needle biopsies also bear the risk of having false-negative results. Material/Methods: 988 core needle breast biopsies were performed at the Maria Sk?odowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, between 01 March 2006 and 29 February 2008. Malignant lesions were diagnosed in 426/988 (43.12%) cases, atypical hyperplasia in 69/988 (6.98%), and benign lesions in 493/988 (49.90%) cases. Results: Twenty-two out of 988 biopsies (2.23%) were found to be false negative. Histopathological assessment of tissue specimens was repeated in these cases. In 14/22 (64%) cases, the previous diagnosis of a benign lesion was changed. In 8/22 (36%) cases, the diagnosis of a benign lesion was confirmed. False-negative rate was calculated at 2.2%. The rate of false-negative diagnoses resulting from a radiological mistake was estimated at 36%. The rate of false-negative diagnoses, resulting from histopathological assessment, was 64%. False-negative results caused by a radiological error comprised 1.5% of all histopathologically diagnosed cancers and atypias (sensitivity of 98.5%). There were no false-positive results in our material - the specificity of the method was 100%. Conclusions: Histopathological interpretation is a substantial cause of false-negative results of breast core needle biopsy. Thus, in case of a radiological-histopathological divergence, histopathological analysis of biopsy specimens should be repeated. The main radiological causes of false-negative results of breast core needle biopsy are as follows: sampling from an inappropriate site and histopathological non-homogeneity of cancer infiltration.

Boba, Marek; Koltun, Urszula; Bobek-Billewicz, Barbara; Chmielik, Ewa; Eksner, Bartosz; Olejnik, Tomasz

2011-01-01

12

A gender difference in the false recall of negative words: women DRM more than men.  

PubMed

Gender differences in susceptibility to associative memory illusions in the Deese/Roediger-McDermott paradigm were investigated using negative and neutral word lists. Women (n=50) and men (n=50) studied 20 lists of 12 words that were associates of a non-presented critical lure. Ten lists were associates of negatively valenced lures (e.g., cry, evil) and ten were associates of neutral lures (e.g., chair, slow). When asked to recall the words after each list, women falsely recalled more negative lures than men, but there was no gender difference in the false recall of neutral lures. These findings suggest that women reflect on associations within negative lists to a greater degree than men and are thereby more likely to generate the negative critical lures. PMID:21432635

Dewhurst, Stephen A; Anderson, Rachel J; Knott, Lauren M

2012-01-01

13

The effects of false positive and false negative physiological feedback on sexual arousal: a comparison of women with or without sexual arousal disorder.  

PubMed

The effects of false positive and false negative physiological feedback (vaginal photoplethymograph response print-out) on women's sexual arousal were examined. Participants included women without sexual dysfunction (n=16) and women with Sexual Arousal Disorder (SAD; n=15). Measures of subjective sexual arousal, physiological sexual arousal (vaginal pulse amplitude), expectancies, affect, and anxiety were obtained in response to viewing an erotic film. Results indicated that false positive feedback significantly increased subjective levels of sexual arousal, whereas false negative feedback significantly decreased subjective levels of sexual arousal in both groups. Sexually functional women had overall higher expectancies for sexual arousal than women with SAD. Unexpectedly, false positive feedback did not significantly impact physiological sexual arousal in sexually functional women; however, it resulted in significantly decreased responses in physiological sexual arousal in women with SAD. False negative feedback had no significant effect on physiological sexual response in sexually functional women or women with SAD. PMID:17333325

McCall, Katie M; Meston, Cindy M

2007-08-01

14

A critical reappraisal of false negative sentinel lymph node biopsy in melanoma.  

PubMed

Lymphatic mapping and sentinel lymph node biopsy (SLNB) have completely changed the clinical management of cutaneous melanoma. This procedure has been accepted worldwide as a recognized method for nodal staging. SLNB is able to accurately determine nodal basin status, providing the most useful prognostic information. However, SLNB is not a perfect diagnostic test. Several large-scale studies have reported a relatively high false-negative rate (5.6-21%), correctly defined as the proportion of false-negative results with respect to the total number of "actual" positive lymph nodes. The main purpose of this review is to address the technical issues that nuclear physicians, surgeons, and pathologists should carefully consider to improve the accuracy of SLNB by minimizing its false-negative rate. In particular, SPECT/CT imaging has demonstrated to be able to identify a greater number of sentinel lymph nodes (SLNs) than those found by planar lymphoscintigraphy. Furthermore, a unique definition in the international guidelines is missing for the operational identification of SLNs, which may be partly responsible for this relatively high false-negative rate of SLNB. Therefore, it is recommended for the scientific community to agree on the radioactive counting rate threshold so that the surgeon can be better radioguided to detect all the lymph nodes which are most likely to harbor metastases. Another possible source of error may be linked to the examination of the harvested SLNs by conventional histopathological methods. A more careful and extensive SLN analysis (e.g. molecular analysis by RT-PCR) is able to find more positive nodes, so that the false-negative rate is reduced. Older age at diagnosis, deeper lesions, histologic ulceration, head-neck anatomical location of primary lesions are the clinical factors associated with false-negative SLNBs in melanoma patients. There is still much controversy about the clinical significance of a false-negative SLNB on the prognosis of melanoma patients. Indeed, most studies have failed to show that there is worse melanoma-specific survival for false-negative compared to true-positive SLNB patients. PMID:24835287

Manca, G; Romanini, A; Rubello, D; Mazzarri, S; Boni, G; Chiacchio, S; Tredici, M; Duce, V; Tardelli, E; Volterrani, D; Mariani, G

2014-06-01

15

Sentinel lymph node mapping in melanoma: the issue of false-negative findings.  

PubMed

Management of cutaneous melanoma has changed after introduction in the clinical routine of sentinel lymph node biopsy (SLNB) for nodal staging. By defining the nodal basin status, SLNB provides a powerful prognostic information. Nevertheless, some debate still surrounds the accuracy of this procedure in terms of false-negative rate. Several large-scale studies have reported a relatively high false-negative rate (5.6%-21%), correctly defined as the proportion of false-negative results with respect to the total number of "actual" positive lymph nodes. In this review, we identified all the technical aspects that the nuclear medicine physician, the surgeon, and the pathologist should take into account to improve accuracy of the procedure and minimize the false-negative rate. In particular, SPECT/CT imaging detects more SLNs than those found by planar lymphoscintigraphy. Furthermore, the nuclear medicine community should reach a consensus on the radioactive counting rate threshold to better guide the surgeon in identifying the lymph nodes with the highest likelihood of housing metastases ("true biologic SLNs"). Analysis of the harvested SLNs by conventional techniques is also a further potential source for error. More accurate SLN analysis (eg, molecular analysis by reverse transcriptase-polymerase chain reaction) and more extensive SLN sampling identify more positive nodes, thus reducing the false-negative rate.The clinical factors identifying patients at higher-risk local recurrence after a negative SLNB include older age at diagnosis, deeper lesions, histological ulceration, and head-neck anatomic location of the primary lesion.The clinical impact of a false-negative SLNB on the prognosis of melanoma patients remains controversial, because the majority of studies have failed to demonstrate overall statistically significant disadvantage in melanoma-specific survival for false-negative SLNB patients compared with true-positive SLNB patients.When new more effective drugs will be available in the adjuvant setting for stage III melanoma patients, the implication of an accurate staging procedure for the sentinel lymph nodes will be crucial for both patients and clinicians. Standardization and accuracy of SLN identification, removal, and analysis are required. PMID:24561692

Manca, Gianpiero; Rubello, Domenico; Romanini, Antonella; Boni, Giuseppe; Chiacchio, Serena; Tredici, Manuel; Mazzarri, Sara; Duce, Valerio; Colletti, Patrick M; Volterrani, Duccio; Mariani, Giuliano

2014-07-01

16

Molar Pregnancy with False Negative ?-hCG Urine in the Emergency Department  

PubMed Central

This case describes an atypical presentation of molar pregnancy in an emergency department patient with abdominal pain and vaginal bleeding. The patient demonstrated clinical features of hydatidiform mole, including acute discharge of a large, grape-like vesicular mass, despite multiple negative urine pregnancy tests. These false-negative qualitative human chorionic gonadotropin assays were likely caused by the “high-dose hook effect” and may have delayed proper care of the patient, who displayed pulmonary choriocarcinoma at the time of diagnosis.

Hunter, Christopher L.; Ladde, Jay

2011-01-01

17

False-negative biopsy urease test in bleeding ulcers caused by the buffering effects of blood  

Microsoft Academic Search

Objectives: A false-negative biopsy urease test (BUT) is common in Helicobacter pylori-associated bleeding peptic ulcers. Although blood in the stomach is thought to interfere with the biopsy urease test, the underlying mechanism remains unknown. This in vitro experiment sought to identify the blood component(s) that interfere with the biopsy urease test, and delineate the mechanism of inhibition. Methods: The modified

W. K. Leung; Joseph J. Y. Sung; Kris L. K. Siu; Francis K. L. Chan; Thomas K. W. Ling; Augustine F. B. Cheng

1998-01-01

18

False-negative biopsy urease test in bleeding ulcers caused by the buffering effects of blood  

Microsoft Academic Search

Objectives:A false-negative biopsy urease test (BUT) is common in Helicobacter pylori-associated bleeding peptic ulcers. Although blood in the stomach is thought to interfere with the biopsy urease test, the underlying mechanism remains unknown. This in vitro experiment sought to identify the blood component(s) that interfere with the biopsy urease test, and delineate the mechanism of inhibition.Methods:The modified Hazell's microtiter test

W. K. Leung; Joseph J. Y. Sung; Kris L. K. Siu; Francis K. L. Chan; Thomas K. W. Ling; Augustine F. B. Cheng; Joseph J Y Sung

1998-01-01

19

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis  

PubMed Central

Background/Purpose In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate. Methods We found 3588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published. Results There was significant variation in the false-negative rate over time with a trend to higher rates over time. There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant. This meta-analysis also indicates a significant change over time in the false-negative rate. Discussion/Conclusions The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

Pesek, Sarah; Ashikaga, Taka; Krag, Lars Erik; Krag, David

2012-01-01

20

Using biological data from field studies with multiple reference sites as a basis for environmental management: the risks for false positives and false negatives.  

PubMed

Field surveys of biological responses can provide valuable information about environmental status and anthropogenic stress. However, it is quite usual for biological variables to differ between sites or change between two periods of time also in the absence of an impact. This means that there is an obvious risk that natural variation will be interpreted as environmental impact, or that relevant effects will be missed due to insufficient statistical power. Furthermore, statistical methods tend to focus on the risks for Type-I error, i.e. false positives. For environmental management, the risk for false negatives is (at least) equally important. The aim of the present study was to investigate how the probabilities for false positives and negatives are affected by experimental set up (number of reference sites and samples per site), decision criteria (statistical method and ?-level) and effect size. A model was constructed to simulate data from multiple reference sites, a negative control and a positive control. The negative control was taken from the same distribution as the reference sites and the positive control was just outside the normal range. Using the model, the probabilities to get false positives and false negatives were calculated when a conventional statistical test, based on a null hypothesis of no difference, was used along with alternative tests that were based on the normal range of natural variation. Here, it is tested if an investigated site is significantly inside (equivalence test) and significantly outside (interval test) the normal range. Furthermore, it was tested how the risks for false positives and false negatives are affected by changes in ?-level and effect size. The results of the present study show that the strategy that best balances the risks between false positives and false negatives is to use the equivalence test. Besides tests with tabulated p-values, estimates generated using a bootstrap routine were included in the present study. The simulations showed that the probability for management errors was smaller for the bootstrap compared to the traditional test and the interval test. PMID:21035245

Hanson, Niklas

2011-03-01

21

Kinetic Evidence of an Apparent Negative Activation Enthalpy in an Organocatalytic Process  

PubMed Central

A combined kinetic and computational study on our tryptophan-based bifunctional thiourea catalyzed asymmetric Mannich reactions reveals an apparent negative activation enthalpy. The formation of the pre-transition state complex has been unambiguously confirmed and these observations provide an experimental support for the formation of multiple hydrogen bonding network between the substrates and the catalyst. Such interactions allow the creation of a binding cavity, a key factor to install high enantioselectivity.

Han, Xiao; Lee, Richmond; Chen, Tao; Luo, Jie; Lu, Yixin; Huang, Kuo-Wei

2013-01-01

22

False negatives in the assessment of lifetime alcohol use disorders: a serious but unappreciated problem.  

PubMed

ABSTRACT. Objective: Some individuals will not meet criteria for a lifetime alcohol use disorder (AUD) at a baseline assessment but will at a follow-up measurement, but not because the disorder began after the initial evaluation. Despite several research implications, this type of unreliability of lifetime AUD estimates has not been studied extensively. The present study investigated the extent of false negatives in the assessment of lifetime AUDs using longitudinal data. Method: A prospective cohort of college freshmen (baseline N = 489) were assessed seven times between ages 18 and 34 years using the Diagnostic Interview Schedule. Individuals were categorized as false negatives at the index assessment using a retrospective (using Diagnostic and Statistical Manual of Mental Disorders, Third Edition [DSM-III], and DSM-IV data), a prospective (using DSM-III data only), and a combined approach (using DSM-III data only). Results: For DSM-IV, of the 29 ostensible new onsets at a follow-up 5 years later (age approximately 34 years), 28 (96%) reported meeting AUD criteria before the index assessment (age approximately 29 years). For DSM-III, of the 25 ostensible new onsets, the retrospective, prospective, and combined approaches categorized 18 (72%) individuals as false negatives at the index assessment. Conclusions: These findings further demonstrate sensitivity issues with lifetime AUD assessments and call into question the validity of "onset" cases that rely on only two waves of data, especially when the follow-up assessment fails to reassess lifetime fully (i.e., across the entire drinking history). (J. Stud. Alcohol Drugs, 75, 530-535, 2014). PMID:24766765

Haeny, Angela M; Littlefield, Andrew K; Sher, Kenneth J

2014-05-01

23

Prenatal diagnosis of neural tube defects. II. Analysis of false positive and false negative alpha-fetoprotein results.  

PubMed

Certain problems and pitfalls attend the use of the alpha-fetoprotein (AFP) assay for the prenatal diagnosis of neural tube defects (NTDs). Analysis of 2495 consecutive cases revealed 57 (2.3%) with amniotic fluid AFP levels greater than 3 SD above the mean. Fetal deaths (9), various fetal abnormalities, (7) and spontaneous abortions (4) occurred among this group. In addition, there were 30 cases with AFP levels greater than + 3 SD above the mean in which a normal child was delivered--a true false positive rate of 1.2%. To determine if the false positive rate could be diminished, 40 amniotic fluid samples with AFP greater than + 2 SD were subjected to further detailed analysis for fetal hemoglobin, total protein, and IgM concentrations. Even with this battery of tests, we estimate that between 1 and 2% of normal amniotic fluids have elevated AFP levels and either fall as expected outside the + 3 SD range, or have elevated AFP levels due to unknown causes. PMID:59328

Milunsky, A; Alpert, E

1976-07-01

24

Minimising Immunohistochemical False Negative ER Classification Using a Complementary 23 Gene Expression Signature of ER Status  

PubMed Central

Background Expression of the oestrogen receptor (ER) in breast cancer predicts benefit from endocrine therapy. Minimising the frequency of false negative ER status classification is essential to identify all patients with ER positive breast cancers who should be offered endocrine therapies in order to improve clinical outcome. In routine oncological practice ER status is determined by semi-quantitative methods such as immunohistochemistry (IHC) or other immunoassays in which the ER expression level is compared to an empirical threshold[1], [2]. The clinical relevance of gene expression-based ER subtypes as compared to IHC-based determination has not been systematically evaluated. Here we attempt to reduce the frequency of false negative ER status classification using two gene expression approaches and compare these methods to IHC based ER status in terms of predictive and prognostic concordance with clinical outcome. Methodology/Principal Findings Firstly, ER status was discriminated by fitting the bimodal expression of ESR1 to a mixed Gaussian model. The discriminative power of ESR1 suggested bimodal expression as an efficient way to stratify breast cancer; therefore we identified a set of genes whose expression was both strongly bimodal, mimicking ESR expression status, and highly expressed in breast epithelial cell lines, to derive a 23-gene ER expression signature-based classifier. We assessed our classifiers in seven published breast cancer cohorts by comparing the gene expression-based ER status to IHC-based ER status as a predictor of clinical outcome in both untreated and tamoxifen treated cohorts. In untreated breast cancer cohorts, the 23 gene signature-based ER status provided significantly improved prognostic power compared to IHC-based ER status (P?=?0.006). In tamoxifen-treated cohorts, the 23 gene ER expression signature predicted clinical outcome (HR?=?2.20, P?=?0.00035). These complementary ER signature-based strategies estimated that between 15.1% and 21.8% patients of IHC-based negative ER status would be classified with ER positive breast cancer. Conclusion/Significance Expression-based ER status classification may complement IHC to minimise false negative ER status classification and optimise patient stratification for endocrine therapies.

Li, Qiyuan; Eklund, Aron C.; Juul, Nicolai; Haibe-Kains, Benjamin; Workman, Christopher T.; Richardson, Andrea L.; Szallasi, Zoltan; Swanton, Charles

2010-01-01

25

Interference between wave modes may contribute to the apparent negative dispersion observed in cancellous bone  

PubMed Central

Previous work has shown that ultrasonic waves propagating through cancellous bone often exhibit a linear-with-frequency attenuation coefficient, but a decrease in phase velocity with frequency (negative dispersion) that is inconsistent with the causality-imposed Kramers–Kronig relations. In the current study, interfering wave modes similar to those observed in bone are shown to potentially contribute to the observed negative dispersion. Biot theory, the modified Biot–Attenborogh model, and experimental results are used to aid in simulating multiple-mode wave propagation through cancellous bone. Simulations entail constructing individual wave modes exhibiting a positive dispersion using plausible velocities and amplitudes, and then summing the individual modes to create mixed-mode output wave forms. Results of the simulations indicate that mixed-mode wave forms can exhibit negative dispersion when analyzed conventionally under the assumption that only one wave is present, even when the individual interfering waves exhibit positive dispersions in accordance with the Kramers–Kronig relations. Furthermore, negative dispersion is observed when little or no visual evidence of interference exists in the time-domain data. Understanding the mechanisms responsible for the observed negative dispersion could aid in determining the true material properties of cancellous bone, as opposed to the apparent properties measured using conventional data analysis techniques.

Anderson, Christian C.; Marutyan, Karen R.; Holland, Mark R.; Wear, Keith A.; Miller, James G.

2008-01-01

26

Brain dead or not? CT angiogram yielding false-negative result on brain death confirmation.  

PubMed

We describe a case of severe traumatic brain injury with multiple facial and skull fractures where CT angiogram (CTA) failed to yield a definite result of brain death as an ancillary test. A 28-year-old man was admitted following a road traffic accident with a Glasgow Coma Score (GCS) of 3/15 and fixed pupils. CT brain revealed uncal herniation and diffuse cerebral oedema with associated multiple facial and skull fractures. 72 h later, his clinical condition remained the same with high intracranial pressure refractory to medical management. Clinical confirmation on brain death was not feasible owing to facial injuries. A CTA, performed to determine brain perfusion, yielded a 'false-negative' result. Skull fractures have possibly led to venous prominence in the cortical and deep venous drainage system. This point needs to be borne in mind while considering CTA as an ancillary test to confirm brain death. PMID:23302550

Johnston, Robyn; Kaliaperumal, Chandrasekaran; Wyse, Gerald; Kaar, George

2013-01-01

27

On minimizing assignment errors and the trade-off between false positives and negatives in parentage analysis.  

PubMed

Genetic parentage analyses provide a practical means with which to identify parent-offspring relationships in the wild. In Harrison et al.'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion-Bayes theorem method was more susceptible to false-positive and false-negative assignments than other methods tested. Here, we analyse and discuss the trade-off between type I and type II errors in parentage analyses. We show that controlling for false-positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false-positive and false-negative assignments in parentage analyses. PMID:24102837

Harrison, Hugo B; Saenz-Agudelo, Pablo; Planes, Serge; Jones, Geoffrey P; Berumen, Michael L

2013-12-01

28

Clinicopathologic Factors Associated With False-Negative Sentinel Lymph-Node Biopsy in Breast Cancer  

PubMed Central

Summary Background Data: Previous studies have suggested a variety of factors that may affect the false negative (FN) rate for sentinel lymph node (SLN) biopsy in breast cancer. Because FN results are relatively rare, no prior studies have had sufficient sample size to allow detailed statistical analysis of factors predicting FN results. Methods: Patients with clinical stage T1-2, N0 invasive breast cancer were enrolled in a prospective, multicenter study. All patients underwent SLN biopsy, followed by planned completion axillary dissection regardless of the SLN results, to assess the FN rate. SLN biopsy was performed using radioactive colloid injection in combination with isosulfan blue dye in 94% of cases. Dermal, subdermal, peritumoral, or subareolar radioactive colloid injection techniques were used at the discretion of each institution. Univariate and multivariate analyses were performed to identify factors associated with a FN result. Results: SLNs were identified in 3870 of 4117 patients (94%). There were 1243 true positive, 2521 true negative, and 106 FN results. Age, histologic subtype, the number of non-SLN removed, tumor palpability, type of breast biopsy, and SLN injection technique were not significant factors. On multivariate analysis, tumor size <2.5 cm, upper outer quadrant tumor location, removal of only a single SLN, minimal surgeon experience, presence of a single positive axillary LN, and use of immunohistochemistry (IHC) for SLN analysis were independently associated with an increased risk of FN results. Conclusions: Surgeon experience, tumor size and location, and the number of SLN removed are preoperative and intraoperative factors that independently predict the risk of a FN result. In contrast to suggestions from other smaller studies, age does not affect the likelihood of a FN result; a lesser, rather than greater, number of positive axillary nodes was associated with an increased likelihood of a FN result; and IHC analysis of the SLN increases, rather than decreases, the risk of FN results.

Martin, Robert C. G.; Chagpar, Anees; Scoggins, Charles R.; Edwards, Michael J.; Hagendoorn, Lee; Stromberg, Arnold J.; McMasters, Kelly M.

2005-01-01

29

Can concurrent core biopsy and fine needle aspiration biopsy improve the false negative rate of sonographically detectable breast lesions?  

PubMed Central

Background The aims of this study were to determine the accuracy of concurrent core needle biopsy (CNB) and fine needle aspiration biopsy (FNAB) for breast lesions and to estimate the false-negative rate using the two methods combined. Methods Over a seven-year period, 2053 patients with sonographically detectable breast lesions underwent concurrent ultrasound-guided CNB and FNAB. The sonographic and histopathological findings were classified into four categories: benign, indeterminate, suspicious, and malignant. The histopathological findings were compared with the definitive excision pathology results. Patients with benign core biopsies underwent a detailed review to determine the false-negative rate. The correlations between the ultrasonography, FNAB, and CNB were determined. Results Eight hundred eighty patients were diagnosed with malignant disease, and of these, 23 (2.5%) diagnoses were found to be false-negative after core biopsy. After an intensive review of discordant FNAB results, the final false-negative rate was reduced to 1.1% (p-value = 0.025). The kappa coefficients for correlations between methods were 0.304 (p-value < 0.0001) for ultrasound and FNAB, 0.254 (p-value < 0.0001) for ultrasound and CNB, and 0.726 (p-value < 0.0001) for FNAB and CNB. Conclusions Concurrent CNB and FNAB under ultrasound guidance can provide accurate preoperative diagnosis of breast lesions and provide important information for appropriate treatment. Identification of discordant results using careful radiological-histopathological correlation can reduce the false-negative rate.

2010-01-01

30

Factors That Affect the False-Negative Outcomes of Fine-Needle Aspiration Biopsy in Thyroid Nodules  

PubMed Central

Background. The purpose of this study was to assess the factors that affect the false-negative outcomes of fine-needle aspiration biopsies (FNABs) in thyroid nodules. Methods. Thyroid nodules that underwent FNAB and surgery between August 2005 and January 2012 were analyzed. FNABs were taken from the suspicious nodules regardless of nodule size. Results. Nodules were analyzed in 2 different groups: Group 1 was the false-negatives (n = 81) and Group 2 was the remaining true-positives, true-negatives, and false-positives (n = 649). A cytopathologist attended in 559 (77%) of FNAB procedures. There was a positive correlation between the nodule size and false-negative rates, and the absence of an interpreting cytopathologist for the examination of the FNAB procedure was the most significant parameter with a 76-fold increased risk of false-negative results. Conclusion. The contribution of cytopathologists extends the time of the procedure, and this could be a difficult practice in centres with high patient turnovers. We currently request the contribution of a cytopathologist for selected patients whom should be followed up without surgery.

Agcaoglu, Orhan; Aksakal, Nihat; Ozcinar, Beyza; Sarici, Inanc S.; Ercan, Gulcin; Kucukyilmaz, Meltem; Yanar, Fatih; Ozemir, Ibrahim A.; Kilic, Berkay; Caglayan, Kasim; Yilmazbayhan, Dilek; Salmaslioglu, Artur; Issever, Halim; Ozarmagan, Selcuk; Erbil, Yesim

2013-01-01

31

False negative rate of syndesmotic injury in pronation-external rotation stage IV ankle fractures  

PubMed Central

Background: To investigate false negative rate in the diagnosis of diastasis on initial static anteroposterior radiograph and reliability of intraoperative external rotational stress test for detection of concealed disruption of syndesmosis in pronation external rotation (PER) stage IV (Lauge-Hansen) ankle fractures. Materials and Methods: We prospectively studied 34 PER stage IV ankle fractures between September 2001 and September 2008. Twenty (59%) patients show syndesmotic injury on initial anteroposterior radiographs. We performed an intraoperative external rotation stress test in other 14 patients with suspicious PER stage IV ankle fractures, which showed no defined syndesmotic injury on anteroposterior radiographs inspite of a medial malleolar fracture, an oblique fibular fracture above the syndesmosis and fracture of the posterior tubercle of the tibia. Results: All 14 fractures showed different degrees of tibiofibular clear space (TFCS) and tibiofibular overlapping (TFO) on the external rotation stress test radiograph compared to the initial plain anteroposterior radiograph. It is important to understand the fracture pattern characterstic of PER stage IV ankle fractures even though it appears normal on anteroposterior radiographs, it is to be confirmed for the concealed syndesmotic injury through a routine intraoperative external rotational stress radiograph.

Song, Kwang-Soon; Kim, Sin-Gi; Lim, Young-Jae; Jeon, Jong-Hyuk; Min, Kyunng-Keun

2013-01-01

32

A highly sensitive telomerase activity assay that eliminates false-negative results caused by PCR inhibitors.  

PubMed

An assay for telomerase activity based on asymmetric polymerase chain reaction (A-PCR) on magnetic beads (MBs) and subsequent application of cycling probe technology (CPT) is described. In this assay, the telomerase reaction products are immobilized on MBs, which are then washed to remove PCR inhibitors that are commonly found in clinical samples. The guanine-rich sequences (5'-(TTAGGG)n-3') of the telomerase reaction products are then preferentially amplified by A-PCR, and the amplified products are subsequently detected via CPT, where a probe RNA with a fluorophore at the 5' end and a quencher at the 3' end is hydrolyzed by RNase H in the presence of the target DNA. The catalyst-mediated cleavage of the probe RNA enhances fluorescence from the 5' end of the probe. The assay allowed us to successfully detect HeLa cells selectively over normal human dermal fibroblast (NHDF) cells. Importantly, this selectivity produced identical results with regard to detection of HeLa cells in the absence and presence of excess NHDF cells; therefore, this assay can be used for practical clinical applications. The lower limit of detection for HeLa cells was 50 cells, which is lower than that achieved with a conventional telomeric repeat amplification protocol assay. Our assay also eliminated false-negative results caused by PCR inhibitors. Furthermore, we show that this assay is appropriate for screening among G-quadruplex ligands to find those that inhibit telomerase activity. PMID:24071983

Yaku, Hidenobu; Murashima, Takashi; Miyoshi, Daisuke; Sugimoto, Naoki

2013-01-01

33

Recurrent\\/metastatic thyroid carcinomas false negative for serum thyroglobulin but positive by posttherapy I-131 whole body scans  

Microsoft Academic Search

Purpose  Serum Tg and I-131 WBS have been used to detect recurrent and metastatic thyroid cancers postoperatively. Tg is known to be\\u000a more sensitive than I-131 WBS, and therefore, false-negative WBS cases with elevated Tg levels are frequently found. However,\\u000a the clinical characteristics of false-negative Tg cases with positive WBS have not been clarified.\\u000a \\u000a \\u000a \\u000a Materials and methods  The authors evaluated 824 postoperative

Eun-Kyung Park; June-Key Chung; Il Han Lim; Do Joon Park; Dong Soo Lee; Myung Chul Lee; Bo Youn Cho

2009-01-01

34

False-negative rate and recovery efficiency performance of a validated sponge wipe sampling method.  

PubMed

Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on recovery efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10 × 10(-3) to 1.86 CFU/cm(2)). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD(90) (?1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm(2) on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions. PMID:22138998

Krauter, Paula A; Piepel, Greg F; Boucher, Raymond; Tezak, Matt; Amidan, Brett G; Einfeld, Wayne

2012-02-01

35

False-Negative Rate and Recovery Efficiency Performance of a Validated Sponge Wipe Sampling Method  

PubMed Central

Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on recovery efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10 × 10?3 to 1.86 CFU/cm2). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD90 (?1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm2 on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions.

Piepel, Greg F.; Boucher, Raymond; Tezak, Matt; Amidan, Brett G.; Einfeld, Wayne

2012-01-01

36

Elimination of False Negative Results with the FPN Forrest Test for Phenothiazine Derivatives in Urine  

Microsoft Academic Search

With the FPN Forrest test for urinary phenothiazine derivatives, omission of drug intake was found to be the most frequent cause of negative color reactions; accord- ingly, these negative reactions are true negatives. Excessive dilution of urine specimens occasionally yielded \\

Irene S. Forrest; Fred M. Forrest; Saul L. Kanter

37

Background parenchymal enhancement at breast MR imaging: normal patterns, diagnostic challenges, and potential for false-positive and false-negative interpretation.  

PubMed

At magnetic resonance (MR) imaging, both normal and abnormal breast tissue enhances after contrast material administration. The morphology and temporal degree of enhancement of pathologic breast tissue relative to normal breast tissue form the basis of MR imaging's diagnostic accuracy in the detection and diagnosis of breast disease. Normal parenchymal enhancement at breast MR imaging is termed background parenchymal enhancement (BPE). BPE may vary in degree and distribution in different patients as well as in the same patient over time. Typically BPE is minimal or mild in overall degree, with a bilateral, symmetric, diffuse distribution and slow early and persistent delayed kinetic features. However, BPE may sometimes be moderate or marked in degree, with an asymmetric or nondiffuse distribution and rapid early and plateau or washout delayed kinetic features. These patterns cause diagnostic difficulty because these features can be seen with malignancy. This article reviews typical and atypical patterns of BPE seen at breast MR imaging. The anatomic and physiologic influences on BPE in women undergoing diagnostic and screening breast MR imaging are reviewed. The potential for false-positive and false-negative interpretations due to BPE are discussed. Radiologists can improve their interpretive accuracy by increasing their understanding of various BPE patterns, influences on BPE, and the potential effects of BPE on MR imaging interpretation. PMID:24428293

Giess, Catherine S; Yeh, Eren D; Raza, Sughra; Birdwell, Robyn L

2014-01-01

38

ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS: Apparently Negative Electric Polarization in Shaped Graded Dielectric Materials  

Microsoft Academic Search

By using a first-principles approach, we investigate the pathway of electric displacement fields in shaped graded dielectric materials existing in the form of cloaks with various shapes. We reveal a type of apparently negative electric polarization (ANEP), which is due to a symmetric oscillation of the paired electric permittivities, satisfying a sum rule. The ANEP does not occur for a

Chun-Zhen Fan; Yin-Hao Gao; Yong Gao; Ji-Ping Huang

2010-01-01

39

Simple duplex fecal PCR assay that allows identification of false-negative results in Helicobacter sp.-infected mice.  

PubMed

We designed a simple and sensitive duplex polymerase chain reaction (PCR) assay for detection of false-negative results during routine Helicobacter sp. feces analysis. We took advantage of the various Lactobacillus species that form part of the normal intestinal flora of laboratory rodents to improve our PCR diagnostic assays. Using this one-step PCR assay, we were able to rule out false-negative results without the need of adding internal standard molecules. This is an important quality control for PCR diagnostic tests, since the presence of inhibitors in feces can prevent detection of Helicobacter infections using PCR analysis. Use of this Lactobacillus group-specific PCR assay can be extended to other feces tests used in mouse quality-control programs. PMID:15575366

Bourgade, Franck; Montagutelli, Xavier; Bigbee, Cassie; Weiss, April; Rigottier-Gois, Lionel; Conti, Claudio J; Benavides, Fernando

2004-10-01

40

False-negative results of a ligase chain reaction assay to detect Chlamydia trachomatis due to inhibitors in urine  

Microsoft Academic Search

The aim of this study was to assess the presence of inhibitors in urine specimens causing false-negative results in a commercialChlamydia trachomatis gap-filling ligase chain reaction (Gap-LCR) assay. On testing of urine samples by the Gap-LCR assay and urethral swab specimens by cell culture, 73 (19%)Chlamydia trachomatis positive subjects were detected among 382 men attending a clinic for sexually transmitted

E. S. Berg; G. Ånestad; H. Moi; G. Størvold; K. Skaug

1997-01-01

41

Genetic deletion of HRP2 and HRP3 in Indian Plasmodium falciparum population and false negative malaria rapid diagnostic test.  

PubMed

Genetic polymorphisms in diagnostic antigens are important factors responsible for variable performance of rapid diagnostic tests. Additionally, the failure of antigen expression due to gene deletion may also contribute to variable performance. We report Indian Plasmodium falciparum field isolates lacking both Pfhrp2 and Pfhrp3 genes leading to false negative results of rapid diagnostic tests. The study highlights need to determine the prevalence of P. falciparum isolates lacking these genes in larger field populations in India. PMID:23041541

Kumar, Navin; Pande, Veena; Bhatt, R M; Shah, Naman K; Mishra, Neelima; Srivastava, Bina; Valecha, Neena; Anvikar, Anupkumar R

2013-01-01

42

Herpes Simplex Encephalitis with Two False-Negative Cerebrospinal Fluid PCR Tests and Review of Negative PCR Results in the Clinical Setting  

PubMed Central

Introduction Herpes simplex virus encephalitis (HSE) is an acute infection accompanied by significant morbidity and mortality with the diagnosis often made by cerebrospinal fluid (CSF) polymerase chain reaction (PCR) testing. Case Presentation We report a case of a healthy 35-year-old woman presenting with altered mental status. Due to suspicion of herpes encephalitis, a CSF PCR for herpes virus was sent for examination and acyclovir was started. The patient had an immediate response to acyclovir; however, when the PCR returned negative she was discharged without therapy. The altered mental status returned and she was started on acyclovir therapy and a second CSF PCR sample was sent and was again negative. MRI performed at initial hospitalization was negative, but a repeat MRI demonstrated bilateral temporal lobe involvement suggestive of herpes encephalitis. The patient was successfully treated for 21 days with acyclovir. Conclusion CSF PCR for herpes virus is highly sensitive and specific and remains the standard for diagnosing herpes encephalitis. Clinicians should be aware of the pitfalls of CSF PCR testing, specifically false-negative results. Although rare, these false negatives can result in premature termination of treatment.

Adler, Adam C.; Kadimi, Srinath; Apaloo, Catherine; Marcu, Corina

2011-01-01

43

A Case of False Negative NIPT for Down Syndrome-Lessons Learned.  

PubMed

Down syndrome or trisomy 21 is the most common cause of prenatal chromosome abnormalities with approximately 50% of all reported chromosome conditions. With the successful introduction of noninvasive prenatal testing (NIPT) for Down syndrome into routine prenatal care, it is important to understand the risks, benefits, and limitations in order to guide patients in making an informed decision. Herein, we describe the first published case report of a patient whose fetus tested "negative" for Trisomy 21 by NIPT but was diagnosed postnatally with trisomy 21. We present the importance of proper pretest and posttest genetic counseling to ensure prenatal patients are able to make informed decisions and are educated appropriately about NIPT. PMID:24649382

Smith, Meagan; Lewis, Kimberly M; Holmes, Alexandrea; Visootsak, Jeannie

2014-01-01

44

Molecular Studies Neglect Apparently Gram-Negative Populations in the Human Gut Microbiota  

PubMed Central

Studying the relationships between gut microbiota, human health, and diseases is a major challenge that generates contradictory results. Most studies draw conclusions about the gut repertoire using a single biased metagenomics approach. We analyzed 16 different stool samples collected from healthy subjects who were from different areas, had metabolic disorders, were immunocompromised, or were treated with antibiotics at the time of the stool collection. The analyses performed included Gram staining, flow cytometry, transmission electron microscopy (TEM), quantitative real-time PCR (qPCR) of the Bacteroidetes and Firmicutes phyla, and pyrosequencing of the 16S rRNA gene amplicons targeting the V6 region. We quantified 1010 prokaryotes per gram of feces, which is less than was previously described. The Mann-Whitney test revealed that Gram-negative proportions of the prokaryotes obtained by Gram staining, TEM, and pyrosequencing differed according to the analysis used, with Gram-negative prokaryotes yielding median percentages of 70.6%, 31.0%, and 16.4%, respectively. A comparison of TEM and pyrosequencing analyses highlighted a difference of 14.6% in the identification of Gram-negative prokaryotes, and a Spearman test showed a tendency toward correlation, albeit not significant, in the Gram-negative/Gram-positive prokaryote ratio (? = 0.3282, P = 0.2146). In contrast, when comparing the qPCR and pyrosequencing results, a significant correlation was found for the Bacteroidetes/Firmicutes ratio (? = 0.6057, P = 0.0130). Our study showed that the entire diversity of the human gut microbiota remains unknown because different techniques generate extremely different results. We found that to assess the overall composition of bacterial communities, multiple techniques must be combined. The biases that exist for each technique may be useful in exploring the major discrepancies in molecular studies.

Hugon, Perrine; Lagier, Jean-Christophe; Robert, Catherine; Lepolard, Catherine; Papazian, Laurent; Musso, Didier; Vialettes, Bernard

2013-01-01

45

Molecular studies neglect apparently gram-negative populations in the human gut microbiota.  

PubMed

Studying the relationships between gut microbiota, human health, and diseases is a major challenge that generates contradictory results. Most studies draw conclusions about the gut repertoire using a single biased metagenomics approach. We analyzed 16 different stool samples collected from healthy subjects who were from different areas, had metabolic disorders, were immunocompromised, or were treated with antibiotics at the time of the stool collection. The analyses performed included Gram staining, flow cytometry, transmission electron microscopy (TEM), quantitative real-time PCR (qPCR) of the Bacteroidetes and Firmicutes phyla, and pyrosequencing of the 16S rRNA gene amplicons targeting the V6 region. We quantified 10(10) prokaryotes per gram of feces, which is less than was previously described. The Mann-Whitney test revealed that Gram-negative proportions of the prokaryotes obtained by Gram staining, TEM, and pyrosequencing differed according to the analysis used, with Gram-negative prokaryotes yielding median percentages of 70.6%, 31.0%, and 16.4%, respectively. A comparison of TEM and pyrosequencing analyses highlighted a difference of 14.6% in the identification of Gram-negative prokaryotes, and a Spearman test showed a tendency toward correlation, albeit not significant, in the Gram-negative/Gram-positive prokaryote ratio (? = 0.3282, P = 0.2146). In contrast, when comparing the qPCR and pyrosequencing results, a significant correlation was found for the Bacteroidetes/Firmicutes ratio (? = 0.6057, P = 0.0130). Our study showed that the entire diversity of the human gut microbiota remains unknown because different techniques generate extremely different results. We found that to assess the overall composition of bacterial communities, multiple techniques must be combined. The biases that exist for each technique may be useful in exploring the major discrepancies in molecular studies. PMID:23885002

Hugon, Perrine; Lagier, Jean-Christophe; Robert, Catherine; Lepolard, Catherine; Papazian, Laurent; Musso, Didier; Vialettes, Bernard; Raoult, Didier

2013-10-01

46

False negativity to carbohydrate-deficient transferrin and drugs: a clinical case  

PubMed Central

Introduction: In this work we report on the possible effect of the medical therapy on CDT concentration in a chronic alcohol abuser, with known medical history (July 2007 – April 2012) and alcohol abuse confirmed by relatives. Case history: At the end of 2007, patient displayed the following laboratory results: AST 137 U/L, ALT 120 U/L, GGT 434 U/L, MCV 101 fL and CDT 3.3%. On December 2007, after double coronary artery bypass surgery, he began a pharmacological treatment with amlodipine, perindopril, atorvastatin, isosorbide mononitrate, carvedilol, ticlopidine and pantoprazole. In the next months, until may 2011, the patient resumed alcohol abuse, as confirmed by relatives; however, CDT values were repeatedly found negative (0.8% and 1.1%) despite elevated transaminases and GGT, concurrent elevated ethyl glucuronide concentration (> 50 mg/L) and blood alcohol concentration (> 1 g/L). Alcohol consumption still continued despite increasing disulfiram doses ordered by an Alcohol Rehab Center. On May 2011, the patient was transferred to a private medical center where he currently lives. Conclusions: This study suggests the possibility that a medical therapy including different drugs may hamper the identification of chronic alcohol abusers by CDT.

Vidali, Matteo; Bianchi, Vincenza; Bagnati, Marco; Atzeni, Nadia; Bianchi, Andrea Marco; Bellomo, Giorgio

2014-01-01

47

Inferential false memories of events: Negative consequences protect from distortions when the events are free from further elaboration.  

PubMed

The present experiment was conducted to investigate whether negative emotionally charged and arousing content of to-be-remembered scripted material would affect propensity towards memory distortions. We further investigated whether elaboration of the studied material through free recall would affect the magnitude of memory errors. In this study participants saw eight scripts. Each of the scripts included an effect of an action, the cause of which was not presented. Effects were either negatively emotional or neutral. Participants were assigned to either a yes/no recognition test group (recognition), or to a recall and yes/no recognition test group (elaboration + recognition). Results showed that participants in the recognition group produced fewer memory errors in the emotional condition. Conversely, elaboration + recognition participants had lower accuracy and produced more emotional memory errors than the other group, suggesting a mediating role of semantic elaboration on the generation of false memories. The role of emotions and semantic elaboration on the generation of false memories is discussed. PMID:23663060

Mirandola, Chiara; Toffalini, Enrico; Grassano, Massimo; Cornoldi, Cesare; Melinder, Annika

2014-07-01

48

False-Positive Papanicolaou (PAP) Test Rates in the College of American Pathologists PAP Education and PAP Proficiency Test Programs: Evaluation of False-Positive Responses of High-Grade Squamous Intraepithelial Lesion or Cancer to a Negative Reference Diagnosis.  

PubMed

Context.-In cytology proficiency testing (PT), participants fail for incorrectly interpreting a high-grade squamous intraepithelial lesion or cancer (HSIL+) Papanicolaou test result as negative. This penalty may lead to a false-positive interpretation of negative slides as HSIL+ to avoid failure. Objective.-To investigate factors related to false-positive responses in a PT versus an educational environment. Design.-We analyzed 420?079 responses from 9414 validated negative reference slides in the College of American Pathologists Interlaboratory Comparison Program in Gynecologic Cytopathology (PAP Education) and compared them with responses from the Gynecologic Cytology Proficiency Testing Program for the percentage of false-positive (HSIL+) interpretations in each of 7 negative subcategories. We evaluated the influence of preparation type (ThinPrep, SurePath, and conventional Papanicolaou test), participant type (pathologist or cytotechnologist), and program time interval (preproficiency test or PT) on a false-positive response. Results.-Reference diagnosis and participant type, but not preparation type, were statistically correlated to false-positive responses. The interaction between program time interval and participant type was also significant. Pathologists had higher rates of false-positive results on preproficiency test (1.2% [800 of 68?690]) than they did on PT (0.8% [993 of 129?857]). Cytotechnologists had no differences between program time intervals (preproficiency, 0.9% [515 of 63?281] versus PT, 1.0 [1231 of 121?621]; P = .91). Negative subcategories frequently mistaken for HSIL+ were reparative changes (4.7% [427 of 9069]), atrophic vaginitis (1.8% [18 of 987]), and negative for intraepithelial lesion or malignancy (1.2% [2143 of 178?651]), but during PT, false-positive rates were significantly increased only for the negative for intraepithelial lesion or malignancy and herpes simplex virus (P < .001). Conclusions.-Pathologists had lower false-positive rates in the Gynecologic Cytology Proficiency Testing Program than they did in PAP Education, but participants were more likely to report a false-positive response (HSIL+) for negative for intraepithelial lesion or malignancy and herpes simplex virus in the Gynecologic Cytology Proficiency Test Program. PMID:24786119

Crothers, Barbara A; Booth, Christine Noga; Darragh, Teresa Marie; Zhao, Chengquan; Souers, Rhona J; Thomas, Nicole; Moriarty, Ann T

2014-05-01

49

The role of "ischemic ST-segment counterpoise" in rendering the response of exercise electrocardiogram falsely negative.  

PubMed

Exercise electrocardiogram (ECG) has a high rate of false negative results in comparison with simultaneously performed thallium-201 perfusion scintigraphy, particularly in patients with single-vessel coronary artery disease, low exercise workload, inadequate heart rate rise, and resting ECG abnormalities. We present the case of a patient in whom thallium-201 SPECT scintigram revealed equally extensive and severe myocardial ischemia in two myocardial planes opposite each other. The accompanying exercise ECG did not disclose ischemic changes despite the adequacy of heart rate rise in this patient with severe right and left anterior descending coronary artery disease. We propose, as an explanation for this phenomenon, that in this patient the ischemic ST-segment vectors of equal magnitude and direction but of opposite sense, generated during stress, cancelled each other ("ischemic ST-segment counterpoise"), thus rendering the exercise ECG normal. PMID:9134283

Madias, J E; Khan, M; Manyam, B

1997-05-01

50

Is It Real False Negative Finding in Motor Evoked Potential Monitoring during Corrective Surgery of Ankylosing Spondylitis? A Case Report  

PubMed Central

We performed L1 posterior vertebral columnar resection and posterior correction for Andersson's lesion and thoracolumbar kyphosis in an ankylosing spondylitis patient during motor evoked potential (MEP) monitoring. We checked MEP intra-operatively, whenever a dangerous procedure for neural elements was performed, and no abnormal findings were seen during surgery. After the operation, we examined neurologic function in the recovery room; the patient showed a progressive neurologic deficit and no response to MEP. After emergency neural exploration and decompression surgery, the neurologic deficit was recovered. We questioned whether to acknowledge the results of this case as a false negative. We think the possible reason for this result may be delayed development of paralysis. So, we recommend that MEP monitoring should be performed not only after important operative steps but also after all steps, including skin suturing, for final confirmation.

Kim, Ki-Tack; Lee, Sang-Hun; Son, Eon-Seok

2012-01-01

51

False-negative serology in patients with neuroborreliosis and the value of employing of different borrelial strains in serological assays.  

PubMed

The risk of obtaining false-negative results in serological assays in serum and CSF specimens with only one strain of Borrelia burgdorferi sensu lato as antigen was investigated in 79 patients with neuroborreliosis with specimens obtained at initial presentation. Serum antibodies were assessed by immunoblotting; the criteria of Hauser et al. were used to evaluate the test. The intrathecal synthesis of borrelial-specific IgM and IgG antibodies was examined by enzyme immunoassay (EIA). Strains of B. burgdorferi sensu stricto (BbZ160), B. garinii (Bbii50) and B. afzelii (PKO) served as sources of antigen in both assays. All patients produced either a positive IgM or IgG test in serum with at least one strain of B. burgdorferi sensu lato. Reactivity of IgM or IgG antibodies, or both, with antigens of all three strains was demonstrated in 67 (85%) of 79 sera. The correlation of results of immunoblotting with different strains was significantly better for IgG (85%) than for IgM antibodies (54%). The variability of positive IgM reactions in 18 specimens was mainly due to the fact that the antibodies were directed to the relevant variable outer-surface protein C (p23). Intrathecal synthesis of IgG antibodies was demonstrated in 58 patients (81%) of 72 and of IgM antibodies in 25 of 58 patients. No patient had isolated intrathecal synthesis of IgM antibodies. The majority of CSF samples (56 of 58) were assessed as IgG antibody-positive, independent of the borrelial strain used as antigen in EIA, whereas only 10 of 25 IgM antibody-positive CSF specimens reacted with all three strains. All patients in the study had intrathecal antibody synthesis demonstrable at 6-week follow-up. From this study it is concluded that there is a small, but real, risk of false-negative serological findings at the time of initial clinical presentation in patients with typical symptoms of neuroborreliosis. In these patients a negative serological result with one strain should prompt the repetition of the test with other strains of B. burgdorferi sensu lato. PMID:11023188

Kaiser, R

2000-10-01

52

Increased false negative rates in sentinel lymph node biopsies in patients with multi-focal breast cancer.  

PubMed

There are few data about the reliability of sentinel node biopsy in patients with multi-focal breast cancer. The aim of this study was to determine the factors affecting the identification and accuracy of the sentinel node, comparing multifocality with other variables, using peritumoral isosulfan blue dye injection technique alone. Between 1998 and 2001, 122 patients with clinically negative nodes from a single institute were eligible for sentinel lymph node biopsies (SLNBs). All patients underwent conventional axillary lymph node dissection (ALND). SLNs were identified in 111 of 122 (91%) cases, and analyzed by hematoxylin and eosin. Twenty-one patients with multifocal breast cancer were determined by clinical or pathologic examination (gross or microscopic). Success in locating the sentinel node was unrelated to patient's age, tumor size, type, location, histological or nuclear grade, multifocality, or a previous surgical biopsy. SLNBs accurately predicted the status of the axilla in 104 of the 111 patients (93.7%), while 18 of the 21 patients with multi-focal breast cancer (85.7%) had successful lymphatic mapping. The false negative (FN) rate was 11.3% among patients with successful SLNBs. Multifocality and tumor size (>2 cm) were associated significantly with decreased accuracy and increased FN rates (for multifocality, p = 0.007 and p = 0.006, and for tumor size >2 cm, p = 0.04 and p = 0.05, respectively) in binary logistic regression analysis, whereas excisional biopsy, tumor location in the upper outer quadrant and patient's age did not significantly affect the accuracy and FN rates in univariate analysis. These results suggest sentinel lymph node biopsy using peritumoral isosulfan blue injection method alone can accurately predict axillary status in patients with clinically negative nodes, but patients with multi-focal disease and large tumor size may not be ideal candidates. PMID:12462384

Ozmen, Vahit; Muslumanoglu, Mahmut; Cabioglu, Neslihan; Tuzlali, Sitki; Ilhan, Ridvan; Igci, Abdullah; Kecer, Mustafa; Bozfakioglu, Yavuz; Dagoglu, Temel

2002-12-01

53

Tracking false-negative results in molecular diagnosis: proposal of a triplex-PCR based method for leishmaniasis diagnosis  

PubMed Central

Background Molecular biological methods have become increasingly relevant to the diagnosis and control of infectious diseases, such as leishmaniasis. Since various factors may affect the sensitivity of PCR assays, including DNA yield and purity, an optimal extraction method is pivotal. Losses of a parasite’s DNA during extraction may significantly impair its detection by PCR and lead to false-negative results. This study proposes a triplex PCR assay targeting the parasite’s DNA, an external control (pUC18) and an internal control (G3PD) for accurate diagnosis of leishmaniasis. Results Two primer pairs were designed to detect the plasmid pUC18 and a triplex PCR assay targeting the Leishmania braziliensis kinetoplast DNA, the external control and the internal control was standardized. The triplex PCR assay was assessed for its ability to detect the three target DNA fragments simultaneously. PCR products from pUC18 DNA resulted in bands of 368 (P1) and 316 (P2) base pairs (bp). The triplex PCR optimized with the chosen external control system (P1) allowed the simultaneous detection of the internal control (G3PD – 567 bp) as well as of small quantities (10 pg) of the target parasite’s DNA, detected by amplification of a 138 bp product. Conclusions The new tool standardized herein enables a more reliable interpretation of PCR results, mainly by contributing to quality assurance of leishmaniasis diagnosis. Furthermore, after simple standardization steps, this protocol could be applied to the diagnosis of other infectious diseases in reference laboratories. This triplex PCR enables the assessment of small losses during the DNA extraction process, problems concerning DNA degradation (sample quality) and the detection of L. braziliensis kDNA.

2014-01-01

54

Effects of Maternal Negativity and of Early and Recent Recurrent Depressive Disorder on Children's False Belief Understanding  

ERIC Educational Resources Information Center

Research has shown that children of depressed mothers are at risk for problems in a variety of developmental domains; however, little is known about the effects of maternal depression on children's emerging understanding of false beliefs. In this study, 3 false belief tasks were administered to 5-year-old children whose mothers had either met…

Rohrer, Lisa M.; Cicchetti, Dante; Rogosch, Fred A.; Toth, Sheree L.; Maughan, Angeline

2011-01-01

55

False Negatives in Sexual Abuse Disclosure InterviewsIncidence and Influence of Caretaker's Belief in Abuse in Cases of Accidental Abuse Discovery by Diagnosis of STD  

Microsoft Academic Search

Verbal disclosure of abuse in a specialized interview was studied in a sample of 28 children, ages 3 to menarche, who presented with purely physical complaints later diagnosed as a sexually transmitted disease, in the absence of any known prior disclosure or suspicion of sexual abuse. Only 43% gave any verbal confirmation of sexual contact. Fifty-seven percent were “false negatives.”

LOUANNE LAWSON; MARK CHAFFIN

1992-01-01

56

Census and Analysis of Persistent False-Negative Results in Serological Diagnosis of Human Immunodeficiency Virus Type 1 Group O Infections?  

PubMed Central

Human immunodeficiency viruses (HIV) have a high level of genetic diversity. The outlier variants of HIV type 1 (HIV-1) group O are distantly related to HIV-1 group M. Their divergence has an impact on serological diagnosis, with a risk of false-negative results. In this study, we report 20 failure cases, involving patients with primary or chronic infection, in France and Cameroon between 2001 and 2008. Our results indicate that some assays detected group O infection much less efficiently than others. Two major reasons for these false-negative results were identified: the presence or absence of a group O-specific antigen (and the designed sequence) for the detection of antibodies and the greater envelope variability of group O than of group M strains. This study highlights the complexity of screening for these divergent variants and the need to evaluate test performance with a large panel of strains, due to the extensive diversity of group O variants.

Plantier, J.-C.; Djemai, M.; Lemee, V.; Reggiani, A.; Leoz, M.; Burc, L.; Vessiere, A.; Rousset, D.; Poveda, J.-D.; Henquell, C.; Gautheret-Dejean, A.; Barin, F.

2009-01-01

57

Are people with negative diabetes screening tests falsely reassured? Parallel group cohort study embedded in the ADDITION (Cambridge) randomised controlled trial  

PubMed Central

Objective To assess whether receiving a negative test result at primary care based stepwise diabetes screening results in false reassurance. Design Parallel group cohort study embedded in a randomised controlled trial. Setting 15 practices (10 screening, 5 control) in the ADDITION (Cambridge) trial. Participants 5334 adults (aged 40-69) in the top quarter for risk of having undiagnosed type 2 diabetes (964 controls and 4370 screening attenders). Main outcome measures Perceived personal and comparative risk of diabetes, intentions for behavioural change, and self rated health measured after an initial random blood glucose test and at 3-6 and 12-15 months later (equivalent time points for controls). Results A linear mixed effects model with control for clustering by practice found no significant differences between controls and people who screened negative for diabetes in perceived personal risk, behavioural intentions, or self rated health after the first appointment or at 3-6 months or 12-15 months later. After the initial test, people who screened negative reported significantly (but slightly) lower perceived comparative risk (mean difference ?0.16, 95% confidence interval ?0.30 to ?0.02; P=0.04) than the control group at the equivalent time point; no differences were evident at 3-6 and 12-15 months. Conclusions A negative test result at diabetes screening does not seem to promote false reassurance, whether this is expressed as lower perceived risk, lower intentions for health related behavioural change, or higher self rated health. Implementing a widespread programme of primary care based stepwise screening for type 2 diabetes is unlikely to cause an adverse shift in the population distribution of plasma glucose and cardiovascular risk resulting from an increase in unhealthy behaviours arising from false reassurance among people who screen negative. Trial registration Current controlled trials ISRCTN99175498.

2009-01-01

58

A case report of false negative Legionella test results in a chlorinated public hot water distribution system due to the lack of sodium thiosulfate in sampling bottles.  

PubMed

We examined samples from the showers and the central water distribution system of a public building with an indoor swimming pool. The pool was used for school and recreational activities and as a sports therapy facility for patients with coronary heart disease. The building's hot water system was contaminated with Legionella pneumophila. Due to the building's intricate piping system, several attempts to completely eliminate legionellae by thermal and chemical disinfection had failed, so an external sanitation company was charged with the installation of a continuous chlorination device in order to keep Legionella concentrations low. The laboratory which was contracted by the sanitation company to monitor bacteria levels after installation of the chlorination device used sampling bottles without sodium thiosulfate and repeatedly reported an absence of Legionella. However, up to 69,000 colony forming particles (CFP) of Legionella pneumophila (Lp) per litre and up to 171 CFP/ml of heterotrophic bacteria could be detected when parallel samples were collected in bottles containing sodium thiosulfate at standard concentrations. Laboratories, epidemiologists, public health officials and technical staff who may be in charge of delivering, preparing or using sterile sampling devices for the collection of environmental samples to be tested for legionellae should be aware that cultures can return false negative results if the sampling containers used to collect chlorinated drinking water or chlorinated pool water samples do not contain a neutralizing agent to instantly inactivate residual halogen biocides. False negative results may lead to a false sense of security regarding the safety of water systems or the success of disinfection measures, and may thus endanger public health or even hinder the epidemiological clarification of outbreaks. PMID:11833297

Wiedenmann, A; Langhammer, W; Botzenhart, K

2001-12-01

59

Negative dispersion in bone: The role of interference in measurements of the apparent phase velocity of two temporally overlapping signals  

PubMed Central

In this study the attenuation coefficient and dispersion (frequency dependence of phase velocity) are measured using a phase sensitive (piezoelectric) receiver in a phantom in which two temporally overlapping signals are detected, analogous to the fast and slow waves typically found in measurements of cancellous bone. The phantom consisted of a flat and parallel Plexiglas™ plate into which a step discontinuity was milled. The phase velocity and attenuation coefficient of the plate were measured using both broadband and narrowband data and were calculated using standard magnitude and phase spectroscopy techniques. The observed frequency dependence of the phase velocity and attenuation coefficient exhibit significant changes in their frequency dependences as the interrogating ultrasonic field is translated across the step discontinuity of the plate. Negative dispersion is observed at specific spatial locations of the plate at which the attenuation coefficient rises linearly with frequency, a behavior analogous to that of bone measurements reported in the literature. For all sites investigated, broadband and narrowband data (3–7 MHz) demonstrate excellent consistency. Evidence suggests that the interference between the two signals simultaneously reaching the phase sensitive piezoelectric receiver is responsible for this negative dispersion.

Bauer, Adam Q.; Marutyan, Karen R.; Holland, Mark R.; Miller, James G.

2008-01-01

60

Are apparent negative effects of feeding GM MON810 maize to Atlantic salmon, Salmo salar, caused by confounding factors?  

PubMed

The present study was conducted to follow up on apparent differences in growth, relative organ sizes, cellular stress and immune function in Atlantic salmon fed feed containing GM Bacillus thuringiensis maize compared with feed containing the non-modified parental maize line. Gene expression profiling on the distal intestinal segment and liver was performed by microarray, and selected genes were followed up by quantitative PCR (qPCR). In the liver, qPCR revealed some differentially regulated genes, including up-regulation of gelsolin precursor, down-regulation of ferritin heavy subunit and a tendency towards down-regulation of metallothionein (MT)-B. This, combined with the up-regulation of anti-apoptotic protein NR13 and similar tendencies for ferritin heavy chain and MT-A and -B in the distal intestine, suggests changes in cellular stress/antioxidant status. This corresponds well with and strengthens previous findings in these fish. To exclude possible confounding factors, the maize ingredients were analysed for mycotoxins and metabolites. The GM maize contained 90 ?g/kg of deoxynivalenol (DON), while the non-GM maize was below the detection limit. Differences were also observed in the metabolite profiles of the two maize varieties, some of which seemed connected to the mycotoxin level. The effects on salmon observed in the present and previous studies correspond relatively well with the effects of DON as reported in the literature for other production animals, but knowledge regarding effects and harmful dose levels in fish is scarce. Thus, it is difficult to conclude whether the observed effects are caused by the DON level or by some other aspect of the GM maize ingredient. PMID:21418706

Sissener, Nini H; Hemre, Gro-Ingunn; Lall, Santosh P; Sagstad, Anita; Petersen, Kjell; Williams, Jason; Rohloff, Jens; Sanden, Monica

2011-07-01

61

The use of core needle biopsy as first-line in diagnosis of thyroid nodules reduces false negative and inconclusive data reported by fine-needle aspiration  

PubMed Central

Background The reported reliability of core needle biopsy (CNB) is high in assessing thyroid nodules after inconclusive fine-needle aspiration (FNA) attempts. However, first-line use of CNB for nodules considered at risk by ultrasonography (US) has yet to be studied. The aim of this study were: 1) to evaluate the potential merit of using CNB first-line instead of conventional FNA in thyroid nodules with suspicious ultrasonographic features; 2) to compare CNB and FNA as a first-line diagnostic procedure in thyroid lesions at higher risk of cancer. Methods Seventy-seven patients with a suspicious-appearing, recently discovered solid thyroid nodule were initially enrolled as study participants. No patients had undergone prior thyroid fine-needle aspiration/biopsy. Based on study design, all patients were proposed to undergo CNB as first-line diagnostic aspiration, while those patients refusing to do so underwent conventional FNA. Results Five patients refused the study, and a total of 31 and 41 thyroid nodules were subjected to CNB and FNA, respectively. At follow-up, the overall rate of malignancy was of 80% (CNB, 77%; FNA, 83%). However, the diagnostic accuracy of CNB (97%) was significantly (P?false negative (N?=?1), indeterminate (N?=?2) or not adequate (N?=?1) samples. Conclusions CNB can reduce the false negative and inconclusive results of conventional FNA and should be considered a first-line method in assessing solid thyroid nodules at high risk of malignancy.

2014-01-01

62

False labor.  

PubMed

The nature of false labor and its influence on the subsequent course of true labor was examined by a retrospective case-controlled matched study of 83 patients admitted in false labor. Patients with a history of false labor had a significantly greater incidence of dysfunctional labor when true labor did commence. The frequency of cesarean section was also higher, though not statistically significantly so. The dilatation of the cervix and the station of the presenting part at admission were both significantly different in patients with false labor from those in true labor; however, the overlap of these two groups makes this of limited clinical use. Time of day and day of the week did not correlate with the likelihood of being admitted in false labor. PMID:3785787

Schauberger, C W

1986-12-01

63

Risks associated with magnetic resonance imaging and cervical collar in comatose, blunt trauma patients with negative comprehensive cervical spine computed tomography and no apparent spinal deficit  

PubMed Central

Introduction In blunt trauma, comatose patients (Glasgow Coma Scale score 3 to 8) with a negative comprehensive cervical spine (CS) computed tomography assessment and no apparent spinal deficit, CS clearance strategies (magnetic resonance imaging [MRI] and prolonged cervical collar use) are controversial. Methods We conducted a literature review to delineate risks for coma, CS instability, prolonged cervical collar use, and CS MRI. Results Based on our search of the literature, the numbers of functional survivor patients among those who had sustained blunt trauma were as follows: 350 per 1,000 comatose unstable patients (increased intracranial pressure [ICP], hypotension, hypoxia, or early ventilator-associated pneumonia); 150 per 1,000 comatose high-risk patients (age > 45 years or Glasgow Coma Scale score 3 to 5); and 600 per 1,000 comatose stable patients (not unstable or high risk). Risk probabilities for adverse events among unstable, high-risk, and stable patients were as follows: 2.5% for CS instability; 26.2% for increased intensive care unit complications with prolonged cervical collar use; 9.3% to 14.6% for secondary brain injury with MRI transportation; and 20.6% for aspiration during MRI scanning (supine position). Additional risk probabilities for adverse events among unstable patients were as follows: 35.8% for increased ICP with cervical collar; and 72.1% for increased ICP during MRI scan (supine position). Conclusion Blunt trauma coma functional survivor (independent living) rates are alarming. When a comprehensive CS computed tomography evaluation is negative and there is no apparent spinal deficit, CS instability is unlikely (2.5%). Secondary brain injury from the cervical collar or MRI is more probable than CS instability and jeopardizes cerebral recovery. Brain injury severity, probability of CS instability, cervical collar risk, and MRI risk assessments are essential when deciding whether CS MRI is appropriate and for determining the timing of cervical collar removal.

Dunham, C Michael; Brocker, Brian P; Collier, B David; Gemmel, David J

2008-01-01

64

Mixed Mycobacterium tuberculosis Complex Infections and False-Negative Results for Rifampin Resistance by GeneXpert MTB/RIF Are Associated with Poor Clinical Outcomes.  

PubMed

The Xpert MTB/RIF (Xpert) assay is becoming a principal screening tool for diagnosing rifampin-resistant Mycobacterium tuberculosis complex (MTBC) infection. However, little is known about the performance of the Xpert assay in infections with both drug-sensitive and drug-resistant strains (mixed MTBC infections). We assessed the performance of the Xpert assay for detecting rifampin resistance using phenotypic drug sensitivity testing (DST) as the reference standard in 370 patients with microbiologically proven pulmonary tuberculosis. Mixed MTBC infections were identified genetically through 24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) analysis. Logistic regression was used to identify the factors associated with poor (defined as treatment failure, default, and death from any cause) or good (defined as cure or successful treatment completion) clinical outcomes. The analytic sensitivity of the Xpert assay for detecting rifampin resistance was assessed in vitro by testing cultures containing different ratios of drug-sensitive and drug-resistant organisms. Rifampin resistance was detected by the Xpert assay in 52 (14.1%) and by phenotypic DST in 55 (14.9%) patients. Mixed MTBC infections were identified in 37 (10.0%) patients. The Xpert assay was 92.7% (95% confidence interval [CI], 82.4% to 97.9%) sensitive for detecting rifampin resistance and 99.7% (95% CI, 98.3% to 99.9%) specific. When restricted to patients with mixed MTBC infections, Xpert sensitivity was 80.0% (95% CI, 56.3 to 94.3%). False-negative Xpert results (adjusted odds ratio [aOR], 6.6; 95% CI,1.2 to 48.2) and mixed MTBC infections (aOR, 6.5; 95% CI, 2.1 to 20.5) were strongly associated with poor clinical outcome. The Xpert assay failed to detect rifampin resistance in vitro when <90% of the organisms in the sample were rifampin resistant. Our study indicates that the Xpert assay has an increased false-negative rate for detecting rifampin resistance with mixed MTBC infections. In hyperendemic settings where mixed infections are common, the Xpert results might need further confirmation. PMID:24789181

Zetola, Nicola M; Shin, Sanghyuk S; Tumedi, Kefentse A; Moeti, Keletso; Ncube, Ronald; Nicol, Mark; Collman, Ronald G; Klausner, Jeffrey D; Modongo, Chawangwa

2014-07-01

65

Mixed Mycobacterium tuberculosis Complex Infections and False-Negative Results for Rifampin Resistance by GeneXpert MTB/RIF Are Associated with Poor Clinical Outcomes  

PubMed Central

The Xpert MTB/RIF (Xpert) assay is becoming a principal screening tool for diagnosing rifampin-resistant Mycobacterium tuberculosis complex (MTBC) infection. However, little is known about the performance of the Xpert assay in infections with both drug-sensitive and drug-resistant strains (mixed MTBC infections). We assessed the performance of the Xpert assay for detecting rifampin resistance using phenotypic drug sensitivity testing (DST) as the reference standard in 370 patients with microbiologically proven pulmonary tuberculosis. Mixed MTBC infections were identified genetically through 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) analysis. Logistic regression was used to identify the factors associated with poor (defined as treatment failure, default, and death from any cause) or good (defined as cure or successful treatment completion) clinical outcomes. The analytic sensitivity of the Xpert assay for detecting rifampin resistance was assessed in vitro by testing cultures containing different ratios of drug-sensitive and drug-resistant organisms. Rifampin resistance was detected by the Xpert assay in 52 (14.1%) and by phenotypic DST in 55 (14.9%) patients. Mixed MTBC infections were identified in 37 (10.0%) patients. The Xpert assay was 92.7% (95% confidence interval [CI], 82.4% to 97.9%) sensitive for detecting rifampin resistance and 99.7% (95% CI, 98.3% to 99.9%) specific. When restricted to patients with mixed MTBC infections, Xpert sensitivity was 80.0% (95% CI, 56.3 to 94.3%). False-negative Xpert results (adjusted odds ratio [aOR], 6.6; 95% CI,1.2 to 48.2) and mixed MTBC infections (aOR, 6.5; 95% CI, 2.1 to 20.5) were strongly associated with poor clinical outcome. The Xpert assay failed to detect rifampin resistance in vitro when <90% of the organisms in the sample were rifampin resistant. Our study indicates that the Xpert assay has an increased false-negative rate for detecting rifampin resistance with mixed MTBC infections. In hyperendemic settings where mixed infections are common, the Xpert results might need further confirmation.

Shin, Sanghyuk S.; Tumedi, Kefentse A.; Moeti, Keletso; Ncube, Ronald; Nicol, Mark; Collman, Ronald G.; Klausner, Jeffrey D.; Modongo, Chawangwa

2014-01-01

66

Touch preparations for the intraoperative evaluation of sentinel lymph nodes after neoadjuvant therapy have high false-negative rates in patients with breast cancer.  

PubMed

Context.- The use of a touch preparation for intraoperative sentinel lymph node diagnosis has become a preferred method of many pathologists because of its reported high sensitivity and rapid turnaround time. However, after neoadjuvant chemotherapy many lymph nodes have significant treatment-related changes that may affect the diagnostic accuracy of the intraoperative evaluation. Objective.- To determine the accuracy of touch preparation for the intraoperative diagnosis of metastatic breast carcinoma in the neoadjuvant setting. Design.- We reviewed retrospectively the results of intraoperative evaluations for 148 different sentinel lymph nodes from 63 patients who had undergone neoadjuvant chemotherapy for invasive breast cancer at our institution. The intraoperative touch preparation results were compared with the final pathology reports in conjunction with relevant clinical data. Results.- Use of touch preparation for the evaluation of sentinel lymph nodes intraoperatively after neoadjuvant therapy was associated with a low sensitivity of 38.6% (95% confidence interval [CI], 24.4-54.5) but high specificity of 100% (95% CI, 96.5-100). There was no difference in sensitivity rates between cytopathologists and noncytopathologists in this cohort (P = .40). Patients with invasive lobular carcinoma and those who had a clinically positive axilla before the initiation of neoadjuvant therapy were the most likely to have a false-negative result at surgery. Conclusions.- Intraoperative touch preparations should not be used alone for the evaluation of sentinel lymph nodes in the setting of neoadjuvant therapy for breast cancer because of low overall sensitivity. PMID:24878021

Elliott, Robin M; Shenk, Robert R; Thompson, Cheryl L; Gilmore, Hannah L

2014-06-01

67

SENTINEL LYMPH NODE BIOPSY IN PATIENTS WITH MULTICENTRIC/MULTIFOCAL BREAST CANCER: LOW FALSE NEGATIVE RATE AND LACK OF AXILLARY RECURRENCE  

PubMed Central

Background Accuracy of sentinel lymph node biopsy (SLNB) and rate of axillary recurrence in multicentric (MC)/multifocal (MF) breast cancer are reported. Methods From 1999–2006, 93 patients with MC/MF breast cancer underwent SLNB; 41 had axillary lymph node dissection (ALND) regardless of SLN pathology (group 1) and 52 had ALND only if a SLN was positive (group 2). Patient demographics, SLN techniques, and pathology were recorded. Results There were no differences between the two groups with respect to patient age, tumor size, grade, stage, histology, or method of SLN detection. The incidence of axillary metastasis was greater in group 1 patients (68%) compared to group 2 patients (12%) (p<0.01). In group 1, the sensitivity and specificity of SLNB were 93% and 100%, with a false negative rate of 7%. None of the 52 patients in group 2 experienced an axillary recurrence (median follow-up 4.8 years). Conclusions The accuracy of SLNB in MC/MF breast cancer is comparable to that observed in unifocal breast cancer. Despite a lower rate of SLN positivity in those undergoing SLNB only, axillary recurrence is not observed.

Holwitt, Dana M.; Gillanders, William E.; Aft, Rebecca L.; Eberlein, Timothy J.; Margenthaler, Julie A.

2014-01-01

68

Specimen Processing and Concentration of Chlamydia trachomatis Added Can Influence False-Negative Rates in the LCx Assay but Not in the APTIMA Combo 2 Assay When Testing for Inhibitors  

PubMed Central

Inhibitors in clinical specimens can be detected by adding the target of nucleic acid amplification to the sample. Introduction of a Chlamydia trachomatis L2 434 preparation containing 12 elementary bodies (EBs) into first-void urine (FVU) from 225 nonpregnant women and 190 pregnant women before specimen processing by the assays produced false-negative rates of 0.48% (2 of 415 specimens) and 13% (44 of 338 specimens) by the APTIMA Combo 2 and the Chlamydia LCx tests, respectively. Reducing the amount of C. trachomatis added to one EB, a concentration closer to the APTIMA Combo 2 test cutoff, for a subset of 244 FVU specimens increased the number of specimens with false-negative results by the APTIMA Combo 2 assay to 7 (2.9%), suggesting that the strength of the input C. trachomatis per specimen has an influence on the number of specimens with false-negative results. Repeat testing after overnight storage and dilution decreased the APTIMA Combo 2 test false-negative rates to 0% (0 of 415 specimens) with the stronger inoculum and 0.8% (2 of 244 specimens) with the weaker inoculum; the false-negative rate of the LCx assay was reduced to 5.4% (18 of 334 specimens). When an additional 70 FVU specimens from women to which 12 EBs were added before specimen processing were tested by the LCx assay, 34 specimens had false-negative results, whereas 21 specimens had false-negative results when the C. trachomatis EBs were introduced after processing. Nine of the 21 specimens to which EBs were added after processing and all of the 34 urine specimens to which the target was added before processing remained falsely negative on repeat testing at a 1:2 dilution, suggesting that input C. trachomatis DNA was lost during processing by the LCx assay. In contrast, the APTIMA Combo 2 assay appears to have a higher sensitivity and either lost little nucleic acid during processing or demonstrated few problems with inhibitors of transcription-mediated amplification.

Chong, S.; Jang, D.; Song, X.; Mahony, J.; Petrich, A.; Barriga, P.; Chernesky, M.

2003-01-01

69

Specimen processing and concentration of Chlamydia trachomatis added can influence false-negative rates in the LCx assay but not in the APTIMA Combo 2 assay when testing for inhibitors.  

PubMed

Inhibitors in clinical specimens can be detected by adding the target of nucleic acid amplification to the sample. Introduction of a Chlamydia trachomatis L2 434 preparation containing 12 elementary bodies (EBs) into first-void urine (FVU) from 225 nonpregnant women and 190 pregnant women before specimen processing by the assays produced false-negative rates of 0.48% (2 of 415 specimens) and 13% (44 of 338 specimens) by the APTIMA Combo 2 and the Chlamydia LCx tests, respectively. Reducing the amount of C. trachomatis added to one EB, a concentration closer to the APTIMA Combo 2 test cutoff, for a subset of 244 FVU specimens increased the number of specimens with false-negative results by the APTIMA Combo 2 assay to 7 (2.9%), suggesting that the strength of the input C. trachomatis per specimen has an influence on the number of specimens with false-negative results. Repeat testing after overnight storage and dilution decreased the APTIMA Combo 2 test false-negative rates to 0% (0 of 415 specimens) with the stronger inoculum and 0.8% (2 of 244 specimens) with the weaker inoculum; the false-negative rate of the LCx assay was reduced to 5.4% (18 of 334 specimens). When an additional 70 FVU specimens from women to which 12 EBs were added before specimen processing were tested by the LCx assay, 34 specimens had false-negative results, whereas 21 specimens had false-negative results when the C. trachomatis EBs were introduced after processing. Nine of the 21 specimens to which EBs were added after processing and all of the 34 urine specimens to which the target was added before processing remained falsely negative on repeat testing at a 1:2 dilution, suggesting that input C. trachomatis DNA was lost during processing by the LCx assay. In contrast, the APTIMA Combo 2 assay appears to have a higher sensitivity and either lost little nucleic acid during processing or demonstrated few problems with inhibitors of transcription-mediated amplification. PMID:12574282

Chong, S; Jang, D; Song, X; Mahony, J; Petrich, A; Barriga, P; Chernesky, M

2003-02-01

70

False Dichotomies.  

ERIC Educational Resources Information Center

Examines the origins and implications of the false dichotomy between teaching and research. Finds the roots of the dichotomy in public schools. Addresses problems caused by failure to recognize the links between teaching and research, including cultural dissonance, faculty isolation from their discipline, and benefits of faculty research. (DMM)

Block, Jonathan

1991-01-01

71

Diagnostic utility of small-caliber and conventional endoscopes for gastric cancer and analysis of endoscopic false-negative gastric cancers  

PubMed Central

AIM: To analyze the diagnostic utility of a small-caliber endoscope (SC-E) and clinicopathological features of false-negative gastric cancers (FN-GCs). METHODS: A total of 21638 esophagogastroduodenoscopy (EGD) gastric cancer (GC) screening examinations were analyzed. Secondary endoscopic examinations (n = 3352) were excluded because most secondary examinations tended to be included in the conventional endoscopy (C-E) group. Detection rates of GCs and FN-GCs were compared between SC-E and C-E groups. FN-GC was defined as GC performed with EGD within the past 3 years without GC detection. Macroscopic types, histopathological characteristics and locations of FN-GCs were compared with firstly found-gastric cancers (FF-GCs) in detail. RESULTS: SC-E cases (n = 6657) and C-E cases (n = 11644), a total of 18301 cases, were analyzed. GCs were detected in 16 (0.24%) SC-E cases and 40 C-E (0.34%) cases (P = 0.23) and there were 4 FN-GCs (0.06%) in SC-E and 13 (0.11%) in C-E (P = 0.27), with no significant difference. FN-GCs/GCs ratio between SC-E and C-E groups was not significantly different (P = 0.75). The comparison of endoscopic macroscopic types of FN-GCs tended to be a less advanced type (P = 0.02). Histopathologically, 70.6% of FN-GCs were differentiated and 29.4% undifferentiated type. On the other hand, 43.0% of FF-GCs were differentiated and 53.8% undifferentiated type, so FN-GCs tended to be more differentiated type (P = 0.048). CONCLUSION: The diagnostic utility of SC-E for the detection of GCs and FN-GCs was not inferior to that of C-E. Careful observation for superficially depressed type lesions in the upper lesser curvature region is needed to decrease FN-GCs.

Kataoka, Hiromi; Mizuno, Kiyoshi; Hayashi, Noriyuki; Tanaka, Mamoru; Nishiwaki, Hirotaka; Ebi, Masahide; Mizoshita, Tsutomu; Mori, Yoshinori; Kubota, Eiji; Tanida, Satoshi; Kamiya, Takeshi; Joh, Takashi

2013-01-01

72

False Memories  

NSDL National Science Digital Library

Use this activity (10th on the page) to help learners explore memory and how sometimes your brain makes up its own memories. Learners will read and try to remember the words in list #1. Five minutes later, learners will try to remember which words on list #2 they remember from list #1. Learners will be surprised to find out that their brains can be easily tricked. This activity guide includes two word challenges. Learners can make up their own lists to see if they can create false memories.

Chudler, Eric H.

2010-01-01

73

False-Negative Hepatitis B Virus (HBV) Surface Antigen in a Vaccinated Dialysis Patient with a High Level of HBV DNA in the United States  

PubMed Central

Screening with hepatitis B surface antigen (HBsAg) is highly recommended for at-risk individuals. Mutations in the HBsAg can result in an inability to detect the virus during routine screening. We describe a hemodialysis patient found to have high levels of hepatitis B virus (HBV) DNA and HBV antibody but negative HBsAg on two routine assays.

Foy, Matthew C.; Thio, Chloe L.; Hwang, Hyon S.; Saulynas, Melissa; Hamilton, James P.; Fine, Derek M.

2012-01-01

74

False-negative hepatitis B virus (HBV) surface antigen in a vaccinated dialysis patient with a high level of HBV DNA in the United States.  

PubMed

Screening with hepatitis B surface antigen (HBsAg) is highly recommended for at-risk individuals. Mutations in the HBsAg can result in an inability to detect the virus during routine screening. We describe a hemodialysis patient found to have high levels of hepatitis B virus (HBV) DNA and HBV antibody but negative HBsAg on two routine assays. PMID:22441395

Foy, Matthew C; Thio, Chloe L; Hwang, Hyon S; Saulynas, Melissa; Hamilton, James P; Fine, Derek M; Atta, Mohamed G

2012-05-01

75

False Alarm Mitigation of Vibration Diagnostic Systems  

Microsoft Academic Search

False alarms in legacy aircraft diagnostic systems have negatively impacted fleet maintenance costs and mission readiness. As the industry moves towards more advanced prognostic and health management (PHM) solutions, a reduction in false alarms is needed to reduce the cost and readiness burdens that have plagued legacy systems. It is therefore important to understand why these false alarms occur and

C. S. Byington; M. J. Watson; Sanket Amin; M. Begin

2008-01-01

76

MSPI False Indication Probability Simulations  

SciTech Connect

This paper examines false indication probabilities in the context of the Mitigating System Performance Index (MSPI), in order to investigate the pros and cons of different approaches to resolving two coupled issues: (1) sensitivity to the prior distribution used in calculating the Bayesian-corrected unreliability contribution to the MSPI, and (2) whether (in a particular plant configuration) to model the fuel oil transfer pump (FOTP) as a separate component, or integrally to its emergency diesel generator (EDG). False indication probabilities were calculated for the following situations: (1) all component reliability parameters at their baseline values, so that the true indication is green, meaning that an indication of white or above would be false positive; (2) one or more components degraded to the extent that the true indication would be (mid) white, and “false” would be green (negative) or yellow (negative) or red (negative). In key respects, this was the approach taken in NUREG-1753. The prior distributions examined were the constrained noninformative (CNI) prior used currently by the MSPI, a mixture of conjugate priors, the Jeffreys noninformative prior, a nonconjugate log(istic)-normal prior, and the minimally informative prior investigated in (Kelly et al., 2010). The mid-white performance state was set at ?CDF = ?10 ? 10-6/yr. For each simulated time history, a check is made of whether the calculated ?CDF is above or below 10-6/yr. If the parameters were at their baseline values, and ?CDF > 10-6/yr, this is counted as a false positive. Conversely, if one or all of the parameters are set to values corresponding to ?CDF > 10-6/yr but that time history’s ?CDF < 10-6/yr, this is counted as a false negative indication. The false indication (positive or negative) probability is then estimated as the number of false positive or negative counts divided by the number of time histories (100,000). Results are presented for a set of base case parameter values, and three sensitivity cases in which the number of FOTP demands was reduced, along with the Birnbaum importance of the FOTP.

Dana Kelly; Kurt Vedros; Robert Youngblood

2011-03-01

77

The False Aneurysm  

PubMed Central

The clinical course of 18 patients with 25 false aneurysms is reviewed. In recent years false aneurysm has been most commonly seen as a complication of arterioplastic procedures in which prosthetic arterial grafts were used. The use of indwelling needles or cannulae, particularly in patients with a wide arterial pulse pressure, can also lead to the formation of false aneurysms. In the groin, a false aneurysm is frequently mistaken for an abscess. Early diagnosis and operative repair are essential to reduce the incidence of further complications.

Baird, R. J.; Doran, M. L.

1964-01-01

78

Atypical rearrangement involving 3?-IGH@ and a breakpoint at least 400 Kb upstream of an intact MYC in a CLL patient with an apparently balanced t(8;14)(q24.1;q32) and negative MYC expression  

PubMed Central

The t(8;14)(q24.1;q32), the cytogenetic hallmark of Burkitt’s lymphoma, is also found, but rarely, in cases of chronic lymphocytic leukemia (CLL). Such translocation typically results in a MYC-IGH@ fusion subsequently deregulating and overexpressing MYC on der 14q32. In CLL, atypical rearrangements resulting in its gain or loss, within or outside of IGH@ or MYC locus, have been reported, but their clinical significance remains uncertain. Herein, we report a 67?year-old male with complex cytogenetic findings of apparently balanced t(8;14) and unreported complex rearrangements of IGH@ and MYC loci. His clinical, morphological and immunophenotypic features were consistent with the diagnosis of CLL. Interphase FISH studies revealed deletions of 11q22.3 and 13q14.3, and an extra copy of IGH@, indicative of rearrangement. Karyotype analysis showed an apparently balanced t(8;14)(q24.1;q32). Sequential GPG-metaphase FISH studies revealed abnormal signal patterns: rearrangement of IGH break apart probe with the 5’-IGH@ on derivative 8q24.1 and the 3’-IGH@ retained on der 14q; absence of MYC break apart-specific signal on der 8q; and, the presence of unsplit 5’-MYC-3’ break apart probe signals on der 14q. The breakpoint on 8q24.1 was found to be at least 400 Kb upstream of 5’ of MYC. In addition, FISH studies revealed two abnormal clones; one with 13q14.3 deletion, and the other, with concurrent 11q deletion and atypical rearrangements. Chromosome microarray analysis (CMA) detected a 7.1?Mb deletion on 11q22.3-q23.3 including ATM, a finding consistent with FISH results. While no significant copy number gain or loss observed on chromosomes 8, 12 and 13, a 455 Kb microdeletion of uncertain clinical significance was detected on 14q32.33. Immunohistochemistry showed co-expression of CD19, CD5, and CD23, positive ZAP-70 expression and absence of MYC expression. Overall findings reveal an apparently balanced t(8;14) and atypical complex rearrangements involving 3’-IGH@ and a breakpoint at least 400 Kb upstream of MYC, resulting in the relocation of the intact 5’-MYC-3’ from der 8q, and apposition to 3’-IGH@ at der 14q. This case report provides unique and additional cytogenetic data that may be of clinical significance in such a rare finding in CLL. It also highlights the utility of conventional and sequential metaphase FISH in understanding complex chromosome anomalies and their association with other clinical findings in patients with CLL. To the best of our knowledge, this is the first CLL reported case with such an atypical rearrangement in a patient with a negative MYC expression.

2013-01-01

79

Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials  

SciTech Connect

Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the false negative rate (FNR). The FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not FNR (which left a major gap in available information). Quantifying the FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The testing was performed by SNL and is now completed. The study investigated the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge-wipe samples, RE, and FNR. The experimental design involves 16 test runs, performed in two blocks of eight runs. Three surface materials (stainless steel, vinyl tile, and ceramic tile) were tested in the first block, while three other surface materials (plastic, painted wood paneling, and faux leather) were tested in the second block. The eight surface concentrations of the surrogate were randomly assigned to test runs within each block. Some of the concentrations were very low and presented challenges for deposition, sampling, and analysis. However, such tests are needed to investigate RE and FNR over the full range of concentrations of interest. In each run, there were 10 test coupons of each of the three surface materials. A positive control sample was generated at the same time as each test sample. The positive control results will be used to 1) calculate RE values for the wipe sampling and analysis method, and 2) fit RE- and FNR-concentration equations, for each of the six surface materials. Data analyses will support 1) estimating the FNR for each combination of contaminant concentration and surface material, 2) estimating the surface concentrations and their uncertainties of the contaminant for each combination of concentration and surface material, 3) estimating RE (%) and their uncertainties for each combination of contaminant concentration and surface material, 4) fitting FNR-concentration and RE-concentration equations for each of the six surface materials, 5) assessing goodness-of-fit of the equations, and 6) quantifying the uncertainty in FNR and RE predictions made with the fitted equations.

Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

2011-05-01

80

Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials  

SciTech Connect

Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the probability of correct detection (PCD) (or equivalently the false negative rate FNR = 1 ? PCD). The PCD/FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5) sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not PCD/FNR (which left a major gap in available information). Quantifying the PCD/FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in PCD/FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The study will investigate the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge-wipe samples, RE, and PCD/FNR. The experimental design involves 16 test runs, to be performed in two blocks of eight runs. Three surface materials (stainless steel, vinyl tile, and ceramic tile) were tested in the first block, while three other surface materials (plastic, painted wood paneling, and faux leather) will be tested in the second block. The eight surface concentrations of the surrogate were randomly assigned to test runs within each block. Some of the concentrations will be very low and may present challenges for deposition, sampling, and analysis. However, such tests are needed to investigate RE and PCD/FNR over the full range of concentrations of interest. In each run, there will be 10 test coupons of each of the three surface materials. A positive control sample will be generated prior to each test sample. The positive control results will be used to 1) calculate RE values for the wipe sampling and analysis method, and 2) fit RE- and PCD-concentration equations, for each of the six surface materials. Data analyses will support 1) estimating the PCD for each combination of contaminant concentration and surface material, 2) estimating the surface concentrations and their uncertainties of the contaminant for each combination of concentration and surface material, 3) estimating RE (%) and their uncertainties for each combination of contaminant concentration and surface material, 4) fitting PCD-concentration and RE-concentration equations for each of the six surface materials, 5) assessing goodness-of-fit of the equations, and 6) quantifying the uncertainty in PCD and RE predictions made with the fitted equations.

Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula; Einfeld, Wayne

2010-12-16

81

'Jibsheet' in False Color  

NASA Technical Reports Server (NTRS)

NASA's Mars Exploration Rover Spirit drove up to this outcrop, called 'Jibsheet,' on the flank of 'Husband Hill,' in early March 2005. This view of Jibsheet by Spirit's panoramic camera is presented in false color.

2005-01-01

82

False Belief vs. False Photographs: A Test of Theory of Mind or Working Memory?  

PubMed Central

Theory of mind (ToM), the ability to reason about other people’s thoughts and beliefs, has been traditionally studied in behavioral and neuroimaging experiments by comparing performance in “false belief” and “false photograph” (control) stories. However, some evidence suggests that these stories are not matched in difficulty, complicating the interpretation of results. Here, we more fully evaluated the relative difficulty of comprehending these stories and drawing inferences from them. Subjects read false belief and false photograph stories followed by comprehension questions that probed true (“reality” questions) or false beliefs (“representation” questions) appropriate to the stories. Stories and comprehension questions were read and answered, respectively, more slowly in the false photograph than false belief conditions, indicating their greater difficulty. Interestingly, accuracy on representation questions for false photograph stories was significantly lower than for all other conditions and correlated positively with participants’ working memory span scores. These results suggest that drawing representational inferences from false photo stories is particularly difficult and places heavy demands on working memory. Extensive naturalistic practice with ToM reasoning may enable a more flexible and efficient mental representation of false belief stories, resulting in lower memory load requirements. An important implication of these results is that the differential modulation of right temporal–parietal junction (RTPJ) during ToM and “false photo” control conditions may reflect the documented negative correlation of RTPJ activity with working memory load rather than a specialized involvement in ToM processes.

Callejas, Alicia; Shulman, Gordon L.; Corbetta, Maurizio

2011-01-01

83

'Methuselah' in False Color  

NASA Technical Reports Server (NTRS)

An outcrop dubbed 'Methuselah,' approached by NASA's Mars Exploration Rover Spirit in April 2005, presented a more extensive exposure of layered rock than Spirit had found in the all its preceding 15 months since landing on Mars. This view of Methuselah by Spirit's panoramic camera is presented in false color.

2005-01-01

84

On false alarm mitigation  

Microsoft Academic Search

Condition-based maintenance (CBM) of complex military vehicles or industrial machines presumes the capability to correctly detect faults in components or subsystems. Faults are malfunctions that are observed in the monitoring system. Two types of errors can occur during automated fault detection: (1) missed detections or (2) false alarms. The practical consequence of either type of error is that a failed

J. R. Bock; T. Brotherton; P. Grabill; D. Gass; J. A. Keller

2006-01-01

85

Mars Rotate (False Color)  

NSDL National Science Digital Library

This site from NASA's Goddard Space Flight Center features an animation of Mars rotating. The visualization was created using data collected by the Mars Orbiting Laser Altimeter (MOLA) on board the Mars Global Surveyor. The animation uses false color to highlight topography, specifically the Hellas Basin, Terra Meridiani, the Tharsis rise, and Lucus Planum. The site also provides still images of the same features.

Studio, Nasa/goddard S.

86

Schizotypy and false memory.  

PubMed

Using the Deese-Roediger-McDermott (DRM) paradigm the present study examined the relationship between schizotypy and recognition memory. Participants scoring in the upper and lower quartile ranges for schizotypy (Schizotypal Personality Questionnaire brief version; SPQ-B) and on each of the SPQ-B subscales (cognitive-perceptual, interpersonal and disorganized) were compared on true and false memory performance. Participants scoring in the lower quartile range on the cognitive-perceptual subscale recognised a higher proportion of both true and false memories than those scoring in the higher quartile range. Participants scoring in the upper quartile on the interpersonal factor recognised fewer true items than those in the lower quartile range. No differences were found for overall schizotypy or on the disorganized subscale. PMID:18817907

Dagnall, Neil; Parker, Andrew

2009-03-01

87

True or False  

NSDL National Science Digital Library

If you're told that a particular drug doesn't cure arthritis, there's a good chance you'll start to think it does. That's according to Ian Skurnik at the University of Toronto and Carolyn Yoon at the University of Michigan. They found that when people were told a statement was false, they remembered the statement itself much better than the warning. This Science Update looks at the research, which leads to these findings and offers links to other resources for further inquiry. There are also links to Science Netlinks Lesson plans for use at the 9-12 grade level.

American Association for the Advancement of Science (;)

2005-04-18

88

Linguistic Determinants of the Difficulty of True-False Test Items  

ERIC Educational Resources Information Center

Adults read a prose passage and responded to passages based on it which were either true or false and were phrased either affirmatively or negatively. True negatives yielded most errors, followed in order by false negatives, true affirmatives, and false affirmatives. (Author/RC)

Peterson, Candida C.; Peterson, James L.

1976-01-01

89

False color viewing device  

DOEpatents

This invention consists of a viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching, the user`s eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

Kronberg, J.W.

1991-05-08

90

False color viewing device  

DOEpatents

A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage.

Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

1992-01-01

91

False color viewing device  

DOEpatents

A viewing device for observing objects in near-infrared false-color comprising a pair of goggles with one or more filters in the apertures, and pads that engage the face for blocking stray light from the sides so that all light reaching the user's eyes come through the filters. The filters attenuate most visible light and pass near-infrared (having wavelengths longer than approximately 700 nm) and a small amount of blue-green and blue-violet (having wavelengths in the 500 to 520 nm and shorter than 435 nm, respectively). The goggles are useful for looking at vegetation to identify different species and for determining the health of the vegetation, and to detect some forms of camouflage. 7 figs.

Kronberg, J.W.

1992-10-20

92

Reduced False Memory after Sleep  

ERIC Educational Resources Information Center

Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False

Fenn, Kimberly M.; Gallo, David A.; Margoliash, Daniel; Roediger, Henry L., III; Nusbaum, Howard C.

2009-01-01

93

Consequences of false-positive screening mammograms.  

PubMed

IMPORTANCE False-positive mammograms, a common occurrence in breast cancer screening programs, represent a potential screening harm that is currently being evaluated by the US Preventive Services Task Force. OBJECTIVE To measure the effect of false-positive mammograms on quality of life by measuring personal anxiety, health utility, and attitudes toward future screening. DESIGN, SETTING, AND PARTICIPANTS The Digital Mammographic Imaging Screening Trial (DMIST) quality-of-life substudy telephone survey was performed shortly after screening and 1 year later at 22 DMIST sites and included randomly selected DMIST participants with positive and negative mammograms. EXPOSURE Mammogram requiring follow-up testing or referral without a cancer diagnosis. MAIN OUTCOMES AND MEASURES The 6-question short form of the Spielberger State-Trait Anxiety Inventory state scale (STAI-6) and the EuroQol EQ-5D instrument with US scoring. Attitudes toward future screening as measured by women's self-report of future intention to undergo mammographic screening and willingness to travel and stay overnight to undergo a hypothetical new type of mammography that would identify as many cancers with half the false-positive results. RESULTS Among 1450 eligible women invited to participate, 1226 (84.6%) were enrolled, with follow-up interviews obtained in 1028 (83.8%). Anxiety was significantly higher for women with false-positive mammograms (STAI-6, 35.2 vs 32.7), but health utility scores did not differ and there were no significant differences between groups at 1 year. Future screening intentions differed by group (25.7% vs 14.2% more likely in false-positive vs negative groups); willingness to travel and stay overnight did not (9.9% vs 10.5% in false-positive vs negative groups). Future screening intention was significantly increased among women with false-positive mammograms (odds ratio, 2.12; 95% CI, 1.54-2.93), younger age (2.78; 1.5-5.0), and poorer health (1.63; 1.09-2.43). Women's anticipated high-level anxiety regarding future false-positive mammograms was associated with willingness to travel overnight (odds ratio, 1.94; 95% CI, 1.28-2.95). CONCLUSIONS AND RELEVANCE False-positive mammograms were associated with increased short-term anxiety but not long-term anxiety, and there was no measurable health utility decrement. False-positive mammograms increased women's intention to undergo future breast cancer screening and did not increase their stated willingness to travel to avoid a false-positive result. Our finding of time-limited harm after false-positive screening mammograms is relevant for clinicians who counsel women on mammographic screening and for screening guideline development groups. PMID:24756610

Tosteson, Anna N A; Fryback, Dennis G; Hammond, Cristina S; Hanna, Lucy G; Grove, Margaret R; Brown, Mary; Wang, Qianfei; Lindfors, Karen; Pisano, Etta D

2014-06-01

94

False Positive Mammograms and Detection Controlled Estimation  

PubMed Central

Objective To investigate the causes of false positive in mammograms. Data Sources Secondary data collected from extracts from computerized medical records from 1999 from five thousand patients at a single hospital in a medium-sized Southern city. Study Design Retrospective analysis of electronic medical data on screening and diagnostic mammograms. Detection-controlled estimation (DCE) was used to compare the efficacy of alternative readers of mammogram films. Analysis was also conducted on follow-up exams of women who tested positive in the first stage of investigation. Key variables included whether the patient had had a prior mammogram, age of the patient, and identifiers for the individual physicians. Data Collection/Extraction Methods Hospital maintains electronic medical records (EMR) on all patients. Extracts were performed on this EMR system under the guidance of clinical expertise. Data were collected for all women who had mammograms in 1999. Random samples were employed for screening mammograms, and all data was used for diagnostic mammograms. Principal Findings Study results imply that access to a previous mammogram greatly reduces the incidence of false positives readings. This has important consequences for benefit-cost, and cost-effectiveness analysis of mammography. Were previous mammograms always available, the results imply the number of false positives would decrease by at least half. The results here also indicate that there is no reason to believe this decrease in false positive would be accompanied by an increase in the number of false negatives. Other attributes also affected the number of false positives. Mondays and Wednesdays appear to be more prone to false positives than the other days in the week. There is also some disparity in false positive outcomes among the five physicians studied. With respect to detection-controlled estimation, the results are mixed. With follow-up data, the DCE estimator appears to generate reasonable, robust results. Without follow-up data, however, the DCE estimator is far less precise. Conclusions Study results imply that access to a previous mammogram reduces by at least half the incidence of false positives readings. This has important consequences for benefit-cost, and cost-effectiveness analysis of mammography.

Kleit, Andrew N; Ruiz, James F

2003-01-01

95

The false classification of extinction risk in noisy environments.  

PubMed

Abundance trends are the basis for many classifications of threat and recovery status, but they can be a challenge to interpret because of observation error, stochastic variation in abundance (process noise) and temporal autocorrelation in that process noise. To measure the frequency of incorrectly detecting a decline (false-positive or false alarm) and failing to detect a true decline (false-negative), we simulated stable and declining abundance time series across several magnitudes of observation error and autocorrelated process noise. We then empirically estimated the magnitude of observation error and autocorrelated process noise across a broad range of taxa and mapped these estimates onto the simulated parameter space. Based on the taxa we examined, at low classification thresholds (30% decline in abundance) and short observation windows (10 years), false alarms would be expected to occur, on average, about 40% of the time assuming density-independent dynamics, whereas false-negatives would be expected to occur about 60% of the time. However, false alarms and failures to detect true declines were reduced at higher classification thresholds (50% or 80% declines), longer observation windows (20, 40, 60 years), and assuming density-dependent dynamics. The lowest false-positive and false-negative rates are likely to occur for large-bodied, long-lived animal species. PMID:24898368

Connors, B M; Cooper, A B; Peterman, R M; Dulvy, N K

2014-07-22

96

False memory in schizophrenia patients with and without delusions.  

PubMed

Delusions are fixed 'false beliefs' and, although a hallmark feature of schizophrenia, no previous study has examined if delusions might be related to 'false memories'. We used the classic Deese-Roediger-McDermott (DRM) paradigm to compare false memory production in schizophrenia patients who were currently experiencing delusions (ED), patients not experiencing delusions (ND) and healthy control participants. The ED group recalled twice as many false-positive memories (i.e., memory for words not previously seen) as both the controls and crucially, the ND group. Both patient groups also recognised fewer correct words than the healthy controls and both showed greater confidence in their false memories; however, on the recognition task, the ED group made more false-negative (i.e. rejecting previously seen words) high confidence responses than the ND group. PMID:20466436

Bhatt, Reena; Laws, Keith R; McKenna, Peter J

2010-07-30

97

Cosmological apparent and trapping horizons  

NASA Astrophysics Data System (ADS)

The dynamics of particle, event, and apparent horizons in Friedmann-Lemaitre-Robertson-Walker space are discussed. The apparent horizon is trapping when the Ricci curvature is positive. This simple criterion coincides with the condition for the Kodama-Hayward apparent horizon temperature to be positive and also discriminates between the timelike and spacelike character of the apparent horizon. We discuss also the entropy of apparent cosmological horizons in extended theories of gravity and we use the generalized 2nd law to discard an exact solution of Brans-Dicke gravity as unphysical.

Faraoni, Valerio

2011-07-01

98

Dividing Attention Lowers Children's but Increases Adults' False Memories  

ERIC Educational Resources Information Center

The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a…

Otgaar, Henry; Peters, Maarten; Howe, Mark L.

2012-01-01

99

Nonlinear dynamics of false bottoms  

NASA Astrophysics Data System (ADS)

Nansen from his observations in the Beaufort Sea published in 1897 noted that heat transfer from the fresh water to the arctic salt water is the only source of ice accretion during the polar summer. This transfer mechanism, unusual at first sight, is responsible for the initiation and evolution of a false bottom ice, changing ice properties to a great extent and affecting various processes while interacting with the ocean and the atmosphere. A false bottom represents a thin layer of ice which forms in summer underneath the floe where fresh water lies between the salt water and the ice. Details of how this process occurs in nature are now emerging from different laboratory and field experiments. The false bottoms appearing at the interface between the fresh and salt water as a result of double-diffusive convection normally lie below surface and under-ice melt ponds. Such false bottoms represent the only significant source of ice growth in the Arctic during the spring-summer period. Their evolution influences the mass balance of the Arctic sea-ice cover recognized as an indicator of climate change. However, the quantity, aerial extent and other properties of false bottoms are difficult to measure because coring under the surface melt ponds leads to direct mixing of surface and under-ice water. This explains why their aerial extent and overall volume is still not known despite the fact that the upper limit of the ice coverage by the false bottom is approximately half of the ice surface. The growth of false bottoms also leads to other important consequences for different physical, chemical and biological processes associated with their dynamics. This study addressed to a broad community of readers is concerned with non-linear behavior of false bottoms including their stochastic dynamics due to possible fluctuations of the main process parameters in the ocean and the atmosphere.

Nizovtseva, Irina; Alexandrov, Dmitri; Ryashko, Lev

2014-05-01

100

[False hydatic aneurysm of the thoraco-abdominal aorta].  

PubMed

Arterial complications of hydatic disease are rarely encountered. We report a false hydatic aneurysm of the thoracoabdominal aorta revealed by ischemic embolism of the lower limbs. Surgical treatment included aorto-aortic prosthesis and albendazol for 6 months. Results at 18 months are excellent with negative hydatic serology. In endemic areas, hydatic disease is a possible cause of false aneurysms. Long-term surveillance is required after curative surgery and medical treatment. PMID:8999043

El Mesnaoui, A; Bensaïd, Y; Ammar, A; El Yagoubi, M; Benabderrazik, T; Benjelloun, A; Benyahia, B

1996-07-01

101

The effect of correlation in false discovery rate estimation  

PubMed Central

Summary The objective of this paper is to quantify the effect of correlation in false discovery rate analysis. Specifically, we derive approximations for the mean, variance, distribution and quantiles of the standard false discovery rate estimator for arbitrarily correlated data. This is achieved using a negative binomial model for the number of false discoveries, where the parameters are found empirically from the data. We show that correlation may increase the bias and variance of the estimator substantially with respect to the independent case, and that in some cases, such as an exchangeable correlation structure, the estimator fails to be consistent as the number of tests becomes large.

Schwartzman, Armin; Lin, Xihong

2011-01-01

102

Evolutionary Psychology and False Confession  

ERIC Educational Resources Information Center

This paper presents comments on Kassin's review, (see record 2005-03019-002) of the psychology of false confessions. The authors note that Kassin's review makes a compelling argument for the need for legal reform in police interrogation practices. Because his work strikes at the heart of the American criminal justice system--its fairness--the…

Bering, Jesse M.; Shackelford, Todd K.

2005-01-01

103

Felt, false, and miserable smiles  

Microsoft Academic Search

Theoretically based distinctions linked to measurable differences in appearance are described for three smiles: felt smiles (spontaneous expressions of positive emotion); false smiles (deliberate attempts to appear as if positive emotion is felt when it isn't); and, miserable smiles (acknowledgements of feeling miserable but not intending to do much about it). Preliminary evidence supports some of the hypotheses about how

Paul Ekman; Wallace V. Friesen

1982-01-01

104

'Larry's Outcrop' in False Color  

NASA Technical Reports Server (NTRS)

A portion of an exposure of bedrock dubbed 'Larry's Outcrop' shows little layering in this view, in contrast to nearby outcrops called 'Methuselah' and 'Jibsheet.' NASA's Mars Exploration Rover Spirit used its panoramic camera in May 2005 to take this image, which is presented in false color.

2005-01-01

105

Tunneling decay of false vortices  

NASA Astrophysics Data System (ADS)

We consider the decay of vortices trapped in the false vacuum of a theory of scalar electrodynamics in 2+1 dimensions. The potential is inspired by models with intermediate symmetry breaking to a metastable vacuum that completely breaks a U(1) symmetry, while in the true vacuum, the symmetry is unbroken. The false vacuum is unstable through the formation of true vacuum bubbles; however, the rate of decay can be extremely long. On the other hand, the false vacuum can contain metastable vortex solutions. These vortices contain the true vacuum inside in addition to a unit of magnetic flux and the appropriate topologically nontrivial false vacuum outside. We numerically establish the existence of vortex solutions which are classically stable; however, they can decay via tunneling. In general terms, they tunnel to a configuration which is a large, thin-walled vortex configuration that is now classically unstable to the expansion of its radius. We compute an estimate for the tunneling amplitude in the semiclassical approximation. We believe our analysis would be relevant to superconducting thin films or superfluids.

Lee, Bum-Hoon; Lee, Wonwoo; MacKenzie, Richard; Paranjape, M. B.; Yajnik, U. A.; Yeom, Dong-han

2013-10-01

106

Sleep loss produces false memories.  

PubMed

People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal",...), lacking the strongest common associate or theme word (here: "black"). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss. PMID:18946511

Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich

2008-01-01

107

Chandra Images and False Color  

NSDL National Science Digital Library

This is the Chandra X-ray Observatory photo album website. It begins with an introduction on the electromagnetic spectrum, focusing on X-rays in particular. It also contains information on false color images. The images in this photo gallery were taken between 1999 and 2004 by the Chandra telescope. Each image includes a description and a link to more information about the object.

Lestition, Kathy

2004-07-14

108

Partial 'Seminole' Panorama (False Color)  

NASA Technical Reports Server (NTRS)

This view from Spirit's panoramic camera is assembled from frames acquired on Martian days, or sols, 672 and 673 (Nov. 23 and 24, 2005) from the rover's position near an outcrop called 'Seminole.' The view is a southward-looking portion of a larger panorama still being completed. This is a false-color version to emphasize geological differences. It is a composite of images shot through three different filters, admitting light of wavelengths 750 nanometers, 530 nanometers and 430 nanometers.

2005-01-01

109

Mood-congruent false memories persist over time.  

PubMed

In this study, we examined the role of mood-congruency and retention interval on the false recognition of emotion laden items using the Deese/Roediger-McDermott (DRM) paradigm. Previous research has shown a mood-congruent false memory enhancement during immediate recognition tasks. The present study examined the persistence of this effect following a one-week delay. Participants were placed in a negative or neutral mood, presented with negative-emotion and neutral-emotion DRM word lists, and administered with both immediate and delayed recognition tests. Results showed that a negative mood state increased remember judgments for negative-emotion critical lures, in comparison to neutral-emotion critical lures, on both immediate and delayed testing. These findings are discussed in relation to theories of spreading activation and emotion-enhanced memory, with consideration of the applied forensic implications of such findings. PMID:24294987

Knott, Lauren M; Thorley, Craig

2014-01-01

110

Developmental trends in different types of spontaneous false memories: implications for the legal field.  

PubMed

In an emerging area of memory research, it is becoming apparent that one particular type of false memory, called spontaneous false memory, follows a developmental trajectory that is the opposite of what is commonly assumed in false memory research - that is, spontaneous false memories are more likely to occur in adults than in children. The present study focused on developmental trends of different types of spontaneous false memories. Specifically, in the current study, 6-8 year-olds, 10-12 year-olds, and adults were presented with two methods to induce spontaneous false memories: (i) semantically related word lists that are commonly used to evoke spontaneous false memories [i.e, Deese-Roediger-McDermott (DRM) paradigm]; and (ii) a video in which related details were not shown but were presented during a recognition task. The results showed that children were more likely to form false memories than adults in the video false memory paradigm, whereas DRM false memories were more evident in adults than in children. Furthermore, we found that on a general level, DRM false memories were positively related to video spontaneous false memories. We explain that stimuli that contain obvious themes attenuate or even reverse developmental trends in spontaneous false memories. PMID:23839901

Otgaar, Henry; Howe, Mark L; Peters, Maarten; Sauerland, Melanie; Raymaekers, Linsey

2013-01-01

111

Caffeine's effects on true and false memory.  

PubMed

Caffeine's effects on recall of word lists were investigated using the Deese-Roediger-McDermott (DRM) paradigm. College students were administered either 200 mg of caffeine or a 250-mg lactose placebo; after 30 min., they were tested on recall using six word lists. Words of each list were semantically related to a single word (a "critical lure") that was not presented in the list. Participants administered caffeine recalled more list words and more critical lures than participants administered lactose. Recall of list words was negatively correlated with recall of critical lures. Caffeine appears to intensify the strength of connections among list words and critical lures, thereby enhancing both true and false memory. PMID:19708406

Capek, Sarah; Guenther, R Kim

2009-06-01

112

Building false memories without suggestions.  

PubMed

People can come to remember doing things they have never done. The question we asked in this study is whether people can systematically come to remember performing actions they never really did, in the absence of any suggestion from the experimenter. People built LEGO vehicles, performing some steps but not others. For half the people, all the pieces needed to assemble each vehicle were laid out in order in front of them while they did the building; for the other half, the pieces were hidden from view. The next day, everyone returned for a surprise recognition test. People falsely and confidently remembered having carried out steps they did not; those who saw all the pieces while they built each vehicle were more likely to correctly remember performing steps they did perform but equally likely to falsely remember performing steps they did not. We explain our results using the source monitoring framework: People used the relationships between actions to internally generate the missing, related actions, later mistaking that information for genuine experience. PMID:22774684

Foster, Jeffrey L; Garry, Maryanne

2012-01-01

113

'Payson' Panorama in False Color  

NASA Technical Reports Server (NTRS)

The panoramic camera aboard NASA's Mars Exploration Rover Opportunity acquired this panorama of the 'Payson' outcrop on the western edge of 'Erebus' Crater during Opportunity's sol 744 (Feb. 26, 2006). From this vicinity at the northern end of the outcrop, layered rocks are observed in the crater wall, which is about 1 meter (3.3 feet) thick. The view also shows rocks disrupted by the crater-forming impact event and subjected to erosion over time.

To the left of the outcrop, a flat, thin layer of spherule-rich soils overlies more outcrop materials. The rover is currently traveling down this 'road' and observing the approximately 25-meter (82-foot) length of the outcrop prior to departing Erebus crater.

The panorama camera took 28 separate exposures of this scene, using four different filters. The resulting panorama covers about 90 degrees of terrain around the rover. This false-color rendering was made using the camera's 753-nanometer, 535-nanometer and 423-nanometer filters. Using false color enhances the subtle color differences between layers of rocks and soils in the scene so that scientists can better analyze them. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

2006-01-01

114

Proactive and Retroactive Effects of Negative Suggestion  

ERIC Educational Resources Information Center

The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false

Brown, Alan S.; Brown, Christine M.; Mosbacher, Joy L.; Dryden, W. Erich

2006-01-01

115

Apparent mineralocorticoid excess (AME) syndrome.  

PubMed

Apparent mineralocorticoid excess (AME) syndrome is a rare autosomal recessive disorder due to the deficiency of 11b hydroxysteroid dehydrogenase type 2 enzyme (11beta-HSD2). Mutations in this gene affect the enzymatic activity resulting to an excess of cortisol, which causes its inappropriate access to mineralocorticoid receptor leading to inherited hypertension.This is a potentially fatal but treatable disorder. We present clinical and molecular studies on two sisters diagnosed as AME. PMID:23665601

Parvez, Yusuf; Sayed, Ola El

2013-04-01

116

Separating intrinsic and apparent anisotropy  

NASA Astrophysics Data System (ADS)

Seismic anisotropy plays a key role in studies of the Earth's rheology and deformation because of its relation to flow-induced lattice-preferred orientation (LPO) of intrinsically anisotropic minerals. In addition to LPO, small-scale heterogeneity produces apparent anisotropy that need not be related to deformation in the same way as intrinsic anisotropy. Quantitative interpretations of observed anisotropy therefore require the separation of its intrinsic and apparent components. We analyse the possibility to separate intrinsic and apparent anisotropy in media with hexagonal symmetry - typically used in surface wave tomography and SKS splitting studies. Our analysis is on the level of the wave equation, which makes it general and independent of specific data types or tomographic techniques. We find that observed anisotropy can be explained by isotropic heterogeneity when elastic parameters take specific combinations of values. In practice, the uncertainties of inferred anisotropy are large enough to ensure that such a combination is always within the error bars. It follows that commonly observed anisotropy can always be explained completely by a purely isotropic laminated medium unless all anisotropic parameters are known with unrealistic accuracy. Most importantly, minute changes in the poorly constrained P wave anisotropy and the parameter ? can switch between the possible or impossible existence of an isotropic equivalent. Important implications of our study include: (1) Intrinsic anisotropy over tomographically resolved length scales is never strictly required when reasonable error bars for anisotropic parameters are taken into account. (2) Currently available seismic observables provide weak constraints on the relative contributions of intrinsic and apparent anisotropy. (3) Therefore, seismic observables alone are not sufficient to constrain the magnitude of mantle flow. (4) Quantitative interpretations of anisotropy in terms of mantle flow require combined seismic/geodynamic inversions, as well as the incorporation of additional data such as topography, gravity and scattered waves.

Fichtner, Andreas; Kennett, Brian L. N.; Trampert, Jeannot

2013-06-01

117

Cape Verde in False Color  

NASA Technical Reports Server (NTRS)

A promontory nicknamed 'Cape Verde' can be seen jutting out from the walls of Victoria Crater in this false-color picture taken by the panoramic camera on NASA's Mars Exploration Rover Opportunity. The rover took this picture on martian day, or sol, 1329 (Oct. 20, 2007), more than a month after it began descending down the crater walls -- and just 9 sols shy of its second Martian birthday on sol 1338 (Oct. 29, 2007). Opportunity landed on the Red Planet on Jan. 25, 2004. That's nearly four years ago on Earth, but only two on Mars because Mars takes longer to travel around the sun than Earth. One Martian year equals 687 Earth days.

This view was taken using three panoramic-camera filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

2007-01-01

118

The processing of positive and negative information  

Microsoft Academic Search

An affirmative statement which is known to be false and the complementary negative statement which is known to be true, provide the same information, i.e. that something is not the case. Similarly, an affirmative statement which is known to be true and the complementary negative statement which is known to be false, both imply that something is the case. (If

P. C. Wason

1959-01-01

119

25 CFR 11.431 - False reports.  

Code of Federal Regulations, 2011 CFR

... BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Criminal Offenses § 11.431 False reports. (a) A person who knowingly gives false information to any law enforcement...

2011-04-01

120

A cautionary note: false homozygosity for BRCA2 6174delT mutation resulting from a single nucleotide polymorphism masking the wt allele.  

PubMed

Sequencing an amplification product of the terminal segment of BRCA2 exon 11 showed apparent homozygosity for the 6174delT mutation in two healthy sisters. Subsequent sequencing of an alternate overlapping amplicon revealed the presence of the 5972C >T polymorphism, which is within the standard upstream amplification primer. This mismatch was responsible for the failure to amplify the normal (5972T) allele in both sisters who were heterozygous for the 6174delT mutation. Though the unexpected finding of apparent homozygosity for the 6174delT mutation prompted re-evaluation of the assay, the potential for false negative results due to masking of a mutation-bearing allele by such a circumstance should be a cautionary note for the testing and also in the interpretation of the results published under such assay conditions. PMID:12080393

Solano, Angela R; Dourisboure, Ricardo J; Weitzel, Jeffrey; Podesta, Ernesto J

2002-06-01

121

Allergen immunotherapy and allergic rhinitis: false beliefs  

PubMed Central

Background Over the last 100 years, several persistent misconceptions or ‘false beliefs’ have built up around allergen immunotherapy and its use in allergic rhinitis. This is perhaps because enthusiastic physicians administered complex allergen extracts to a diverse population of patients suffering from heterogeneous atopic conditions. Here, we review evidence that counters seven of these ‘false beliefs.’ Discussion 1. The symptoms of allergic rhinitis can be more heterogeneous, more severe and more troublesome in everyday life than many physicians believe. Large-scale epidemiological surveys show that the majority of allergic rhinitis patients have at least one symptom severe enough to interfere with sleep quality, productivity and/or well-being. 2. Allergen immunotherapy is not necessarily suitable for all allergic rhinitis patients (notably those with mild symptoms). Recent evidence from double-blind, placebo-controlled, randomized clinical trials suggests that the more severe the disease, the greater the treatment effect. 3. Allergen immunotherapy is often accused of lack of efficacy (relative to pharmacotherapy, for example). However, there are now many meta-analyses, systematic reviews and high-quality clinical trials that find overwhelmingly in favor of the efficacy of allergen immunotherapy (including sublingual formulations) in allergic rhinitis induced by pollen and, increasingly, other allergens. 4. Natural-exposure and challenge-chamber trials have shown that symptom relief may become apparent within months or even weeks of the initiation of allergen immunotherapy. 5. In pollen-induced allergic rhinitis, several years of subcutaneous or sublingual allergen immunotherapy are associated with sustained clinical efficacy after subsequent treatment cessation – confirming the disease-modifying nature of this therapy. 6. Most patients seeking treatment for allergic rhinitis are polysensitized, and allergen immunotherapy has proven efficacy in large, robust clinical trials in these groups. Polysensitization is not a contraindication to allergen immunotherapy. 7. Sublingual allergen immunotherapy is safe for home administration. A recent review calculated that 1 billion doses were administered worldwide between 2000 and 2010 and found that the 11 case reports of anaphylaxis (all non-fatal) corresponded to non-standard practice. Summary Modern, evidence-based medicine has generated more than enough robust evidence to remove misconceptions about allergen immunotherapy and allergic rhinitis.

2013-01-01

122

Removing False Paths from Combinational Modules 1  

Microsoft Academic Search

The existence of false paths complicates the task of accurate tim- ing analysis significantly. A technique to remove false paths from a combinational circuit without degrading its performance h as a prac- tical value since topological timing analysis is then good e nough to estimate the performance of false-path-free circuits accu rately. One can think of the KMS algorithm (1)

Yuji Kukimoto; Robert K. Brayton

123

An Association Account of False Belief Understanding  

ERIC Educational Resources Information Center

The elicited-response false belief task has traditionally been considered as reliably indicating that children acquire an understanding of false belief around 4 years of age. However, recent investigations using spontaneous-response tasks suggest that false belief understanding emerges much earlier. This leads to a developmental paradox: if young…

De Bruin, L. C.; Newen, A.

2012-01-01

124

Can fabricated evidence induce false eyewitness testimony?  

Microsoft Academic Search

SUMMARY False information can influence people's beliefs and memories. But can fabricated evidence induce individuals to accuse another person of doing something they never did? We examined whether exposure to a fabricated video could produce false eyewitness testimony. Subjects completed a gambling task alongside a confederate subject, and later we falsely told subjects that their partner had cheated on the

Kimberley A. Wade; Sarah L. Green; Robert A. Nash

2009-01-01

125

Pluto behaving badly: false beliefs and their consequences.  

PubMed

We exposed college students to suggestive materials in order to lead them to believe that, as children, they had a negative experience at Disneyland involving the Pluto character. A sizable minority of subjects developed a false belief or memory that Pluto had uncomfortably licked their ear. Suggestions about a positive experience with Pluto led to even greater acceptance of a lovable ear-licking episode. False beliefs and memories had repercussions; those seduced by the bad suggestions were not willing to pay as much for a Pluto souvenir. These findings are among the first to demonstrate that false beliefs can have repercussions for people, meaning that they can influence their later thoughts, beliefs, and behaviors. PMID:19105582

Berkowitz, Shari R; Laney, Cara; Morris, Erin K; Garry, Maryanne; Loftus, Elizabeth F

2008-01-01

126

Venus - False Color of Eistla Regio  

NASA Technical Reports Server (NTRS)

This false color Magellan image shows a portion of Eistla Regio (region) in the northern hemisphere of Venus, centered at 1 degrees south latitude, 37 degrees east longitude. The area is 440 kilometers (270 miles) wide and 350 kilometers (220 miles) long. This image was produced from Magellan radar data collected in Cycle 2 of the mission. Cycle 2 was completed January 15, 1992. The area was not imaged during the first cycle because of superior conjunction when the sun was between the Earth and Venus, preventing communication with the spacecraft. This image contains examples of several of the major geologic terrains on Venus and illustrates the basic stratigraphy or sequence of geologic events. The oldest terrain appears as bright, highly fractured or chaotic highlands rising out of the plains. This is seen in the right half of the image. The chaotic highlands, sometimes called tessera, may represent older and thicker crustal material and occupy about 15 percent of the surface of Venus. The fractured terrain in this region has a distinctly linear structure with a shear-like pattern. Plains surround and embay the fractured highland tessera. Plains are formed by fluid volcanic flows that may have once formed vast lava seas which covered all the low lying surfaces. Plains comprise more than 80 percent of the surface of Venus. The most recent activity in the region is volcanism that produced the radar bright flows best seen in the upper left quadrant of the image. The flows are similar, in their volcanic origin to the darker plains volcanics, but apparently have more rugged surfaces that more efficiently scatter the radar signal back to the spacecraft. The geologic sequence is early fracturing of the tessera, flooding by extensive plains lavas, and scattered less extensive individual flows on the plains surface. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft.

1992-01-01

127

Venus - False Color of Bereghinya Planitia  

NASA Technical Reports Server (NTRS)

This false color Magellan image shows a portion of Bereghinya Planitia (plains) in the northern hemisphere of Venus, centered at 31 degrees north latitude, 43 degrees east longitude. The area is 260 kilometers (160 miles) wide and 330 kilometers (200 miles) long. This image was produced from Magellan radar data collected in Cycle 2 of the mission. Cycle 2 was completed January 15, 1992. The area was not imaged during the first cycle because of superior conjunction when the sun was between the Earth and Venus, preventing communication with the spacecraft. This image contains examples of several of the major geologic terrains on Venus and illustrates the basic stratigraphy or sequence of geologic events. The oldest terrains appear as bright, highly-fractured or chaotic highlands rising out of the plains. This is seen in the upper right and lower left quadrants of the image. The chaotic highlands, sometimes called tessera, may represent older and thicker crustal material and occupy about 15 percent of the surface of Venus. Plains surround and embay the fractured highland tessera. Plains are formed by fluid volcanic flows that may have once formed vast lava seas which covered all the low lying surfaces. Plains comprise more than 80 percent of the surface of Venus. The most recent activity in the region is volcanism that produced the radar bright flows best seen in the lower right quadrant of the image. The lava flows in this image are associated with the shield volcano Tepev Mons whose summit is near the lower left corner of the image. The flows are similar to the darker plains volcanics, but apparently have more rugged surfaces that more efficiently scatter the radar signal back to the spacecraft. The geologic sequence is early fracturing of the tessera, flooding by extensive plains lavas and scattered, less extensive individual flows on the plains surface. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft.

1992-01-01

128

Color correspondence in apparent motion.  

PubMed

To maintain figural identity during motion perception, the visual system must match images over space and time. Correct matching requires a metric for identifying "corresponding" images, those representing the same physical object. To test whether matching is based on achromatic (black/white) polarity and chromatic (red/green) color, observers viewed an ambiguous motion display and judged the path of apparent motion. Matching preserved black/white identity regardless of whether frames were viewed binocularly or dichoptically. Red/green identity was also preserved, but coherence of motion depended in part on the number of frames in the motion sequence and on the background luminance. These results suggest that correspondence is computed by a weighted metric containing terms for image features coded early in visual processing. PMID:2913564

Green, M

1989-01-01

129

Color logic of apparent motion.  

PubMed

Two shapes of either the same or different color will seem to be in smooth apparent motion with like-colored mates, at proper conditions of flash timing and spacing. An experiment is reported in which the condition was tested for unlike-colored pairs, for example red-green alternated with green-red. The question of interest was how the visual system would resolve the disparity of color. An 'intelligent' solution would rotate the shapes in three dimensions. Like-colored and unlike-colored parts were found to move and transform similarly, however, the resolution being dependent more upon timing than upon color. The motion of intelligence as it might be applied to vision is discussed in light of these results. PMID:6514510

Kolers, P A; Green, M

1984-01-01

130

Confabulation versus experimentally induced false memories in Korsakoff patients.  

PubMed

The present study focuses on both the clinical symptom of confabulation and experimentally induced false memories in patients suffering from Korsakoff's syndrome. Despite the vast amount of case studies of confabulating patients and studies investigating false memories in the Deese-Roediger-McDermott (DRM) paradigm, the nature of Korsakoff patients' confabulatory behaviour and its association with DRM false memories have been rarely examined. Hence, the first aim of the present study was to evaluate confabulatory responses in a large sample of chronic Korsakoff patients and matched controls by means of the Dalla Barba Confabulation Battery. Second, the association between (provoked) confabulation and the patients' DRM false recognition performance was investigated. Korsakoff patients mainly confabulated in response to questions about episodic memory and questions to which the answer was unknown. A positive association was obtained between confabulation and the tendency to accept unstudied distractor words as being old in the DRM paradigm. On the other hand, there was a negative association between confabulation and false recognition of critical lures. The latter could be attributed to the importance of strategic retrieval at delayed memory testing. PMID:19930792

Van Damme, Ilse; d'Ydewalle, Géry

2010-09-01

131

5 CFR 531.410 - Reconsideration of a negative determination.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Reconsideration of a negative determination. 531.410 Section... § 531.410 Reconsideration of a negative determination. (a) When an agency head, or his or her designee, issues a negative determination the following...

2010-01-01

132

5 CFR 531.410 - Reconsideration of a negative determination.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Reconsideration of a negative determination. 531.410 Section... § 531.410 Reconsideration of a negative determination. (a) When an agency head, or his or her designee, issues a negative determination the following...

2009-01-01

133

Minimizing False-Positives in Universal Newborn Hearing Screening: A Simple Solution  

Microsoft Academic Search

Background and Objectives. The false- positive rates of previously reported universal newborn hearing screening (UNHS) programs range between 2.5% and 8%. Critics of UNHS programs have claimed that this rate is too high and might lead to a number of the negative effects produced by false-positive screening tests, namely emotional trauma, disease labeling, iatro- genesis from unnecessary testing, and increased

Conrad J. Clemens; Sherri A. Davis

2001-01-01

134

The generalized Chen's conjecture on biharmonic submanifolds is false  

Microsoft Academic Search

The generalized Chen's conjecture on biharmonic submanifolds asserts that any biharmonic submanifold of a non-positively curved manifold is minimal (see e.g., [CMO1], [MO], [BMO1], [BMO2], [BMO3], [Ba1], [Ba2], [Ou1], [Ou2], [IIU]). In this paper, we prove that this conjecture is false by constructing foliations of proper biharmonic hyperplanes in a 5-dimensional conformally flat space with negative sectional curvature. Many examples

YE-LIN OUAND; Liang Tang

2010-01-01

135

Mimas Showing False Colors #2  

NASA Technical Reports Server (NTRS)

This false color image of Saturn's moon Mimas reveals variation in either the composition or texture across its surface.

During its approach to Mimas on Aug. 2, 2005, the Cassini spacecraft narrow-angle camera obtained multi-spectral views of the moon from a range of 228,000 kilometers (142,500 miles).

This image is a color composite of narrow-angle ultraviolet, green, infrared and clear filter images, which have been specially processed to accentuate subtle changes in the spectral properties of Mimas' surface materials. To create this view, three color images (ultraviolet, green and infrared) were combined with a single black and white picture that isolates and maps regional color differences to create the final product.

Shades of blue and violet in the image at the right are used to identify surface materials that are bluer in color and have a weaker infrared brightness than average Mimas materials, which are represented by green.

Herschel crater, a 140-kilometer-wide (88-mile) impact feature with a prominent central peak, is visible in the upper right of the image. The unusual bluer materials are seen to broadly surround Herschel crater. However, the bluer material is not uniformly distributed in and around the crater. Instead, it appears to be concentrated on the outside of the crater and more to the west than to the north or south. The origin of the color differences is not yet understood. It may represent ejecta material that was excavated from inside Mimas when the Herschel impact occurred. The bluer color of these materials may be caused by subtle differences in the surface composition or the sizes of grains making up the icy soil.

This image was obtained when the Cassini spacecraft was above 25 degrees south, 134 degrees west latitude and longitude. The Sun-Mimas-spacecraft angle was 45 degrees and north is at the top.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

2005-01-01

136

Mimas Showing False Colors #1  

NASA Technical Reports Server (NTRS)

False color images of Saturn's moon, Mimas, reveal variation in either the composition or texture across its surface.

During its approach to Mimas on Aug. 2, 2005, the Cassini spacecraft narrow-angle camera obtained multi-spectral views of the moon from a range of 228,000 kilometers (142,500 miles).

The image at the left is a narrow angle clear-filter image, which was separately processed to enhance the contrast in brightness and sharpness of visible features. The image at the right is a color composite of narrow-angle ultraviolet, green, infrared and clear filter images, which have been specially processed to accentuate subtle changes in the spectral properties of Mimas' surface materials. To create this view, three color images (ultraviolet, green and infrared) were combined into a single black and white picture that isolates and maps regional color differences. This 'color map' was then superimposed over the clear-filter image at the left.

The combination of color map and brightness image shows how the color differences across the Mimas surface materials are tied to geological features. Shades of blue and violet in the image at the right are used to identify surface materials that are bluer in color and have a weaker infrared brightness than average Mimas materials, which are represented by green.

Herschel crater, a 140-kilometer-wide (88-mile) impact feature with a prominent central peak, is visible in the upper right of each image. The unusual bluer materials are seen to broadly surround Herschel crater. However, the bluer material is not uniformly distributed in and around the crater. Instead, it appears to be concentrated on the outside of the crater and more to the west than to the north or south. The origin of the color differences is not yet understood. It may represent ejecta material that was excavated from inside Mimas when the Herschel impact occurred. The bluer color of these materials may be caused by subtle differences in the surface composition or the sizes of grains making up the icy soil.

The images were obtained when the Cassini spacecraft was above 25 degrees south, 134 degrees west latitude and longitude. The Sun-Mimas-spacecraft angle was 45 degrees and north is at the top.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

2005-01-01

137

19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.  

Code of Federal Regulations, 2013 CFR

...descriptions; false marking of articles of gold or silver. 11.13 Section 11.13...descriptions; false marking of articles of gold or silver. (a) Articles which...Articles made in whole or in part of gold or silver or alloys thereof...

2013-04-01

138

19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.  

Code of Federal Regulations, 2011 CFR

...descriptions; false marking of articles of gold or silver. 11.13 Section 11.13...descriptions; false marking of articles of gold or silver. (a) Articles which...Articles made in whole or in part of gold or silver or alloys thereof...

2011-04-01

139

19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.  

Code of Federal Regulations, 2012 CFR

...descriptions; false marking of articles of gold or silver. 11.13 Section 11.13...descriptions; false marking of articles of gold or silver. (a) Articles which...Articles made in whole or in part of gold or silver or alloys thereof...

2012-04-01

140

19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.  

Code of Federal Regulations, 2010 CFR

...descriptions; false marking of articles of gold or silver. 11.13 Section 11.13...descriptions; false marking of articles of gold or silver. (a) Articles which...Articles made in whole or in part of gold or silver or alloys thereof...

2010-04-01

141

19 CFR 11.13 - False designations of origin and false descriptions; false marking of articles of gold or silver.  

...descriptions; false marking of articles of gold or silver. 11.13 Section 11.13...descriptions; false marking of articles of gold or silver. (a) Articles which...Articles made in whole or in part of gold or silver or alloys thereof...

2014-04-01

142

Negative Numbers  

NSDL National Science Digital Library

This article is an account of how negative numbers became part of the "vocabulary" of mathematicians and of some of the earliest appearances of negative numbers in calculations of the ancient civilizations of China, India and Greece. Although negative numbers were used in calculations, negative answers to mathematical problems were considered meaningless or impossible. The troubled history of negative numbers presented in this article shows how the simple mathematical principles taken for granted today have taken thousands of years to develop.

Howard, Jill

2009-05-01

143

LVIS Tree Height Cross Section (false color)  

NSDL National Science Digital Library

This animation starts with a false-color map of tree heights north of San Jose, Costa Rica, and changes to a close-up 3D cut-away of a section of the forest, also in false color. Data from LVIS observations taken in March, 1998.

Jones, Randall; Blair, Bryan

1999-09-17

144

Mediastinal false aneurysm after thoracic aortic surgery  

Microsoft Academic Search

Background. Postoperative mediastinal false aneurysm is associated with a substantial morbidity and mortality. Surgical treatment is mandatory, although the individual approach varies according to the type of pathologic process, infection status, and site of origin of the aneurysm.Methods. Between April 1993 and February 1999, we treated 10 patients, aged 25 to 73 years, with anastomotic mediastinal false aneurysm originating from

Takahiro Katsumata; Narain Moorjani; Giuseppe Vaccari; Stephen Westaby

2000-01-01

145

How Does Distinctive Processing Reduce False Recall?  

ERIC Educational Resources Information Center

False memories arising from associatively related lists are a robust phenomenon that resists many efforts to prevent it. However, a few variables have been shown to reduce this form of false memory. Explanations for how the reduction is accomplished have focused on either output monitoring processes or constraints on access, but neither idea alone…

Hunt, R. Reed; Smith, Rebekah E.; Dunlap, Kathryn R.

2011-01-01

146

Poor working memory predicts false memories  

Microsoft Academic Search

Two studies investigated whether individual differences in simple span verbal working memory and complex working memory capacity are related to memory accuracy and susceptibility to false memory development. In Study 1, undergraduate students (N=60) were given two simple span working memory tests: forward and backward digit span. They also underwent a memory task that is known to elicit false memories

Maarten J. V. Peters; Marko Jelicic; Hilde Verbeek; Harald Merckelbach

2007-01-01

147

Explaining the Development of False Memories.  

ERIC Educational Resources Information Center

Reviews explanatory dimensions of children's false memory relevant to forensic practice: measurement, development, social factors, individual differences, varieties of memories and memory judgments, and varieties of procedures inducing false memories. Asserts that recent studies fail to use techniques that separate acquiescence from memory…

Reyna, Valerie F.; Holliday, Robyn; Marche, Tammy

2002-01-01

148

Emotional content of true and false memories  

Microsoft Academic Search

Many people believe that emotional memories (including those that arise in therapy) are particularly likely to represent true events because of their emotional content. But is emotional content a reliable indicator of memory accuracy? The current research assessed the emotional content of participants’ pre-existing (true) and manipulated (false) memories for childhood events. False memories for one of three emotional childhood

Cara Laney; Elizabeth F. Loftus

2008-01-01

149

Reducing False Positives in Runtime Analysis of Deadlocks  

NASA Technical Reports Server (NTRS)

This paper presents an improvement of a standard algorithm for detecting dead-lock potentials in multi-threaded programs, in that it reduces the number of false positives. The standard algorithm works as follows. The multi-threaded program under observation is executed, while lock and unlock events are observed. A graph of locks is built, with edges between locks symbolizing locking orders. Any cycle in the graph signifies a potential for a deadlock. The typical standard example is the group of dining philosophers sharing forks. The algorithm is interesting because it can catch deadlock potentials even though no deadlocks occur in the examined trace, and at the same time it scales very well in contrast t o more formal approaches to deadlock detection. The algorithm, however, can yield false positives (as well as false negatives). The extension of the algorithm described in this paper reduces the amount of false positives for three particular cases: when a gate lock protects a cycle, when a single thread introduces a cycle, and when the code segments in different threads that cause the cycle can actually not execute in parallel. The paper formalizes a theory for dynamic deadlock detection and compares it to model checking and static analysis techniques. It furthermore describes an implementation for analyzing Java programs and its application to two case studies: a planetary rover and a space craft altitude control system.

Bensalem, Saddek; Havelund, Klaus; Clancy, Daniel (Technical Monitor)

2002-01-01

150

Negative Leadership.  

National Technical Information Service (NTIS)

Senior leaders must have the moral courage to modify the behavior or eliminate negative leadership in the Army. If action is not taken immediately, negative leaders and their toxic leadership style will be taught to their subordinates, the future leaders ...

D. M. Oberlander

2013-01-01

151

"False Fonde Bookes, Ballades and Rimes": An Aspect of Informal Education in Early Modern England.  

ERIC Educational Resources Information Center

Explains the negative response of those in authority to early modern English literature which informally educated the population through "false fonde bookes, ballades, and rimes." This negative response, based on both moral and political grounds, came from clerics who saw such books as detrimental to the social structure of society. (BSR)

Charlton, Kenneth

1987-01-01

152

Self-reversal and apparent magnetic excursions in Arctic sediments  

NASA Astrophysics Data System (ADS)

The Arctic oceans have been fertile ground for the recording of apparent excursions of the geomagnetic field, implying that the high latitude field had unusual characteristics at least over the last 1-2 Myrs. Alternating field demagnetization of the natural remanent magnetization (NRM) of Core HLY0503-6JPC from the Mendeleev Ridge (Arctic Ocean) implies the presence of primary magnetizations with negative inclination apparently recording excursions in sediments deposited during the Brunhes Chron. Thermal demagnetization, on the other hand, indicates the presence of multiple (often anti-parallel) magnetization components with negative inclination components having blocking temperatures predominantly, but not entirely, below ~ 350 °C. Thermo-magnetic tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate that the negative inclination components are carried by titanomaghemite, presumably formed by seafloor oxidation of titanomagnetite. The titanomaghemite apparently carries a chemical remanent magnetization (CRM) that is partially self-reversed relative to the detrital remanent magnetization (DRM) carried by the host titanomagnetite. The partial self-reversal could have been accomplished by ionic ordering during oxidation, thereby changing the balance of the magnetic moments in the ferrimagnetic sublattices.

Channell, J. E. T.; Xuan, C.

2009-06-01

153

25 CFR 11.404 - False imprisonment.  

Code of Federal Regulations, 2011 CFR

... BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Criminal Offenses § 11.404 False imprisonment. A person commits a misdemeanor if he or she knowingly restrains another...

2011-04-01

154

20 CFR 356.3 - False claims.  

Code of Federal Regulations, 2013 CFR

...Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT CLAIMS OR STATEMENTS CIVIL MONETARY PENALTY INFLATION ADJUSTMENT § 356.3 False claims. In the case of penalties assessed under 31 U.S.C. 3729 based on actions...

2013-04-01

155

False Assumptions Can Get You in Trouble  

NSDL National Science Digital Library

In this lesson, short deceptive problem stories are presented to the class and students are challenged to solve each problem by asking only yes/no questions. The key is for students to recognize: what the False Assumption is that makes the solution tricky; that many common problems are difficult to solve because we tend to assume a particular paradigm; and that science is a way to work around or through those false assumptions.

Randak, Steve

156

An apparent hiatus in global warming?  

NASA Astrophysics Data System (ADS)

Global warming first became evident beyond the bounds of natural variability in the 1970s, but increases in global mean surface temperatures have stalled in the 2000s. Increases in atmospheric greenhouse gases, notably carbon dioxide, create an energy imbalance at the top-of-atmosphere (TOA) even as the planet warms to adjust to this imbalance, which is estimated to be 0.5-1 W m-2 over the 2000s. Annual global fluctuations in TOA energy of up to 0.2 W m-2 occur from natural variations in clouds, aerosols, and changes in the Sun. At times of major volcanic eruptions the effects can be much larger. Yet global mean surface temperatures fluctuate much more than these can account for. An energy imbalance is manifested not just as surface atmospheric or ground warming but also as melting sea and land ice, and heating of the oceans. More than 90% of the heat goes into the oceans and, with melting land ice, causes sea level to rise. For the past decade, more than 30% of the heat has apparently penetrated below 700 m depth that is traceable to changes in surface winds mainly over the Pacific in association with a switch to a negative phase of the Pacific Decadal Oscillation (PDO) in 1999. Surface warming was much more in evidence during the 1976-1998 positive phase of the PDO, suggesting that natural decadal variability modulates the rate of change of global surface temperatures while sea-level rise is more relentless. Global warming has not stopped; it is merely manifested in different ways.

Trenberth, Kevin E.; Fasullo, John T.

2013-12-01

157

Negative Influence  

NSDL National Science Digital Library

This chapter is all about negative numbers, and how to deal with them. They're not all that difficult to understand, but for some reason people get just a little uptight when they see computations involving negative numbers. I'm guessing that the apprehension results from the view that negative numbers mean there are more rules to follow--rules you don't necessarily understand. Well, we'll try and correct that.

Robertson, William C.

2006-01-01

158

[False-positive diagnostic findings in acoustic neurinomas].  

PubMed

In the period from 1976 to 1990 Tos and Thomsen operated on 520 patients with acoustic neuromas using the translabyrinthine approach and five other patients were operated on via middle fossa approach. The diagnostic work up in all patients included: pure tone audiometry, tympanogram with acoustic reflexes, caloric test and brainstem audiometry. Since the late seventies, CT became the radiological investigation of choice to visualize the tumor. The first generation of CT failed to reveal tumors less than 1.5 cm in the extrameatal diameter, and pantopaque cisternography was necessary in some cases. The following generation of CT did not always reveal small intrameatal tumors, and false-negative results were reported. The incidence of false-positive CT findings in our series is calculated to be 0.6%. Three patients were operated on on account of false-positive CT. Peroperatively, adhesions in and around the internal porus were found in two cases while no pathology was found in the third case. Postoperatively, anacusis was observed in two cases. This could have been avoided if magnetic resonance imaging (MRI) with gadolinium contrast had been performed. In our opinion, MRI should be considered before a definitive surgical procedure is undertaken. Until MRI becomes more widely available, intravenous contrast-enhanced tomography followed by air cisternography is recommended in the diagnosis of small acoustic neuromas. PMID:1781059

Charabi, S; Thomsen, J C; Tos, M

1991-12-30

159

Social network analysis of web links to eliminate false positives in collaborative anti-spam systems  

Microsoft Academic Search

The performance of today's email anti-spam systems is primarily measured by the percentage of false positives (non-spam messages detected as spam) rather than by the percentage of false negatives (real spam messages left unblocked). One reliable anti-spam technique is the Universal Resource Locator (URL)-based filter, which is utilized by most collaborative signature-based filters. URL-based filters examine URL frequency in incoming

Zac Sadan; David G. Schwartz

2011-01-01

160

Photographs cause false memories for the news.  

PubMed

What is the effect on memory when seemingly innocuous photos accompany false reports of the news? We asked people to read news headlines of world events, some of which were false. Half the headlines appeared with photographs that were tangentially related to the event; others were presented without photographs. People saw each headline only once, and indicated whether they remembered the event, knew about it, or neither. Photos led people to immediately and confidently remember false news events. Drawing on the Source Monitoring Framework (Johnson, Hashtroudi, & Lindsay, 1993), we suggest that people often relied on familiarity and other heuristic processes when making their judgments and thus experienced effects of the photos as evidence of memory for the headlines. PMID:21062659

Strange, Deryn; Garry, Maryanne; Bernstein, Daniel M; Lindsay, D Stephen

2011-01-01

161

Why `false' colours are seen by butterflies  

NASA Astrophysics Data System (ADS)

Light can be described by its intensity, spectral distribution and polarization, and normally a visual system analyses these independently to extract the maximum amount of information. Here I present behavioural evidence that this does not happen in butterflies, whose choice of oviposition substrate on the basis of its colour appears to be strongly influenced by the direction of polarization of the light reflected from the substrate. To my knowledge, this is the first record of `false' colours being perceived as a result of light polarization. This detection of false colours may help butterflies to find optimal oviposition sites.

Kelber, Almut

1999-11-01

162

Modeling human false alarms using clutter metrics  

NASA Astrophysics Data System (ADS)

The TSSIM clutter metrics correlate amazingly well to both the experimental detection probabilities and the mean detection time. Based on the analysis of both probabilities of the correct detections and of the total (correct and false) number of detections made by human observers, a mathematical formula for predicting the probability of false alarms as a function of clutter metrics is presented in this paper. Comparing real experimental data with the predicted products reveal very good agreement, which is very helpful in understanding human behavior mechanisms regarding target detection tasks. It is concluded that the human observer behaves as fixed threshold signal processor /Non-CFAR.

Chang, Honghua; Zhang, Jianqi; Liu, Delian

2007-11-01

163

Experimental investigation of false positive errors in auditory species occurrence surveys  

USGS Publications Warehouse

False positive errors are a significant component of many ecological data sets, which in combination with false negative errors, can lead to severe biases in conclusions about ecological systems. We present results of a field experiment where observers recorded observations for known combinations of electronically broadcast calling anurans under conditions mimicking field surveys to determine species occurrence. Our objectives were to characterize false positive error probabilities for auditory methods based on a large number of observers, to determine if targeted instruction could be used to reduce false positive error rates, and to establish useful predictors of among-observer and among-species differences in error rates. We recruited 31 observers, ranging in abilities from novice to expert, that recorded detections for 12 species during 180 calling trials (66,960 total observations). All observers made multiple false positive errors and on average 8.1% of recorded detections in the experiment were false positive errors. Additional instruction had only minor effects on error rates. After instruction, false positive error probabilities decreased by 16% for treatment individuals compared to controls with broad confidence interval overlap of 0 (95% CI: -46 to 30%). This coincided with an increase in false negative errors due to the treatment (26%; -3 to 61%). Differences among observers in false positive and in false negative error rates were best predicted by scores from an online test and a self-assessment of observer ability completed prior to the field experiment. In contrast, years of experience conducting call surveys was a weak predictor of error rates. False positive errors were also more common for species that were played more frequently, but were not related to the dominant spectral frequency of the call. Our results corroborate other work that demonstrates false positives are a significant component of species occurrence data collected by auditory methods. Instructing observers to only report detections they are completely certain are correct is not sufficient to eliminate errors. As a result, analytical methods that account for false positive errors will be needed, and independent testing of observer ability is a useful predictor for among-observer variation in observation error rates.

Miller, David A. W.; Weir, Linda A.; McClintock, Brett T.; Grant, Evan H. Campbell; Bailey, Larissa L.; Simons, Theodore R.

2012-01-01

164

Negative Staining  

NSDL National Science Digital Library

This video from CUNY Kingsborough Community College describes negative staining. The brief demonstration is described step by step and would be easy to replicate in a laboratory setting. Running time for the video is 1:32.

2013-06-21

165

Reducing False Positives in Molecular Pattern Recognition  

Microsoft Academic Search

In the search for new cancer subtypes by gene expression proling, it is essential to avoid misclassifying samples of unknown subtypes as known ones. In this paper, we evaluated the false positive error rates of several classication algorithms through a 'null test' by presenting classiers a large collection of independent samples that do not belong to any of the tumor

Xijin Ge; Shuichi Tsutsumi; Hiroyuki Aburatani; Shuichi Iwata

2003-01-01

166

False Spider Mites of Mexico ('Tenuipalpidae: Acari').  

National Technical Information Service (NTIS)

The bulletin includes descriptions and figures for 165 species of plant-feeding false spider mites (Tenuipalpidae) of Mexico, of which 65 are described as new to science. Less than one-third (48) of the Mexican tenuipalpids are distributed in 8 genera (Ae...

D. M. Tuttle E. W. Baker

1987-01-01

167

What Makes Language Learners False Beginners?  

ERIC Educational Resources Information Center

A study in Japan investigated second language skill loss and maintenance in three groups of English-as-a-Second-Language learners: (1) ninth graders studying basic vocabulary and sentence structures (true beginners); (2) students in the lowest level English class at a technical college, but with some English language skills (false beginners); and…

Nakamura, Tomoko

168

Diseases of Camelina sativa (false flax)  

Microsoft Academic Search

There is renewed interest in the crucifer Camelina sativa (false flax, camelina, gold of pleasure) as an alternative oilseed crop because of its potential value for food, feed, and industrial applications. This species is adapted to canola-growing areas in many regions of the world and is generally considered to be resistant to many diseases. A review of the literature indicates

G. Séguin-Swartz; C. Eynck; R. K. Gugel; S. E. Strelkov; C. Y. Olivier; J. L. Li; H. Klein-Gebbinck; H. Borhan; C. D. Caldwell; K. C. Falk

2009-01-01

169

How to Justify Teaching False Science  

ERIC Educational Resources Information Center

We often knowingly teach false science. Such a practice conflicts with a prima facie pedagogical value placed on teaching only what is true. I argue that only a partial dissolution of the conflict is possible: the proper aim of instruction in science is not to provide an armory of facts about what things the world contains, how they interact, and…

Slater, Matthew H.

2008-01-01

170

Semantic processing in "associative" false memory.  

PubMed

We studied the semantic properties of a class of illusions, of which the Deese/Roediger-McDermott (DRM) paradigm is the most prominent example, in which subjects falsely remember words that are associates of studied words. We analyzed DRM materials for 16 dimensions of semantic content and assessed the ability of these dimensions to predict interlist variability in false memory. For the more general class of illusions, we analyzed pairs of presented and unpresented words that varied in associative strength for the presence of these same 16 semantic properties. DRM materials proved to be exceptionally rich in meaning, as indexed by these semantic properties. Variability in false recall, false recognition, and backward associative strength loaded on a single semantic factor (familiarity/meaningfulness), whereas variability in true recall loaded on a quite different factor (imagery/concreteness). For word association generally, 15 semantic properties varied reliably with forward or backward association between words. Implications for semantic versus associative processing in this class of illusions, for dual-process theories, and for semantic properties of word associations are discussed. PMID:19001566

Brainerd, C J; Yang, Y; Reyna, V F; Howe, M L; Mills, B A

2008-12-01

171

WINDS AND CURRENT PATTERNS IN FALSE BAY  

Microsoft Academic Search

Wind records from six reporting stations in the vicinity of False Bay have been analysed, and the mean directional frequency and velocity combined to give relative ‘wind run’ for each station and season are shown in the form of wind roses.Methods of current measurements are briefly discussed, and the ‘dye-bomb’ technique using aircraft chosen to obtain a nearly synoptic pattern

G. R. Atkins

1970-01-01

172

Combining email models for false positive reduction  

Microsoft Academic Search

Machine learning and data mining can be effectively used to model, classify and discover interesting information for a wide variety of data including email. The Email Mining Toolkit, EMT, has been designed to provide a wide range of analyses for arbitrary email sources. Depending upon the task, one can usually achieve very high accuracy, but with some amount of false

Shlomo Hershkop; Salvatore J. Stolfo

2005-01-01

173

Detecting false intent using eye blink measures  

PubMed Central

Eye blink measures have been shown to be diagnostic in detecting deception regarding past acts. Here we examined—across two experiments with increasing degrees of ecological validity—whether changes in eye blinking can be used to determine false intent regarding future actions. In both experiments, half of the participants engaged in a mock crime and then transported an explosive device with the intent of delivering it to a “contact” that would use it to cause a disturbance. Eye blinking was measured for all participants when presented with three types of questions: relevant to intent to transport an explosive device, relevant to intent to engage in an unrelated illegal act, and neutral questions. Experiment 1 involved standing participants watching a video interviewer with audio presented ambiently. Experiment 2 involved standing participants questioned by a live interviewer. Across both experiments, changes in blink count during and immediately following individual questions, total number of blinks, and maximum blink time length differentiated those with false intent from truthful intent participants. In response to questions relevant to intent to deliver an explosive device vs. questions relevant to intent to deliver illegal drugs, those with false intent showed a suppression of blinking during the questions when compared to the 10 s period after the end of the questions, a lower number of blinks, and shorter maximum blink duration. The results are discussed in relation to detecting deception about past activities as well as to the similarities and differences to detecting false intent as described by prospective memory and arousal.

Marchak, Frank M.

2013-01-01

174

False discovery and false nondiscovery rates in single-step multiple testing procedures  

Microsoft Academic Search

Results on the false discovery rate (FDR) and the false nondiscovery rate (FNR) are developed for single-step multiple testing procedures. In addition to verifying desirable properties of FDR and FNR as measures of error rates, these results extend previously known results, providing further insights, particularly under dependence, into the notions of FDR and FNR and related measures. First, considering fixed

Sanat K. Sarkar

2006-01-01

175

Apparent soil electrical conductivity measurements in agriculture  

Microsoft Academic Search

The field-scale application of apparent soil electrical conductivity (ECa) to agriculture has its origin in the measurement of soil salinity, which is an arid-zone problem associated with irrigated agricultural land and with areas having shallow water tables. Apparent soil electrical conductivity is influenced by a combination of physico-chemical properties including soluble salts, clay content and mineralogy, soil water content, bulk

D. L. Corwin; S. M. Lesch

2005-01-01

176

Apparent Thermal Conductivity Of Multilayer Insulation  

NASA Technical Reports Server (NTRS)

Mathematical model of apparent or effective thermal conductivity between two successive layers of multilayer thermal insulation (MLI) offers potential for optimizing performance of insulation. One gains understanding of how each physical mechanism contributes to overall flow of heat through MLI blanket. Model helps analyze engineering tradeoffs among such parameters as number of layers, thicknesses of gaps between layers, types of spacers placed in gaps, weight, overall thickness, and effects of foregoing on apparent thermal conductivity through blanket.

Mcintosh, Glen E.

1995-01-01

177

Spirit Beholds Bumpy Boulder (False Color)  

NASA Technical Reports Server (NTRS)

As NASA's Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder sits about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of 'Low Ridge.' The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.

Spirit took this false-color image with the panoramic camera on the rover's 810th sol, or Martian day, of exploring Mars (April 13, 2006). This image is a false-color rendering using camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

2006-01-01

178

Cosmic chirality both true and false.  

PubMed

The discrete symmetries of parity P, time reversal T, and charge conjugation C may be used to characterize the properties of chiral systems. It is well known that parity violation infiltrates into ordinary matter via an interaction between the nucleons and electrons, mediated by the Z(0) particle, that lifts the degeneracy of the mirror-image enantiomers of a chiral molecule. Being odd under P but even under T, this P-violating interaction exhibits true chirality and so may induce absolute enantioselection under all circumstances. It has been suggested that CP violation may also infiltrate into ordinary matter via a P-odd, T-odd interaction mediated by the (as yet undetected) axion. This CP-violating interaction exhibits false chirality and so may induce absolute enantioselection in processes far from equilibrium. Both true and false cosmic chirality should be considered together as possible sources of homochirality in the molecules of life. PMID:22930646

Barron, Laurence D

2012-12-01

179

The problem with false vacuum Higgs inflation  

NASA Astrophysics Data System (ADS)

We investigate the possibility of using the only known fundamental scalar, the Higgs, as an inflaton with minimal coupling to gravity. The peculiar appearance of a plateau or a false vacuum in the renormalised effective scalar potential suggests that the Higgs might drive inflation. For the case of a false vacuum we use an additional singlet scalar field, motivated by the strong CP problem, and its coupling to the Higgs to lift the barrier allowing for a graceful exit from inflation by mimicking hybrid inflation. We find that this scenario is incompatible with current measurements of the Higgs mass and the QCD coupling constant and conclude that the Higgs can only be the inflaton in more complicated scenarios.

Fairbairn, Malcolm; Grothaus, Philipp; Hogan, Robert

2014-06-01

180

Effectively Using Syntax for Recognizing False Entailment  

Microsoft Academic Search

Recognizing textual entailment is a chal- lenging problem and a fundamental com- ponent of many applications in natural language processing. We present a novel framework for recognizing textual entail- ment that focuses on the use of syntactic heuristics to recognize false entailment. We give a thorough analysis of our sys- tem, which demonstrates state-of-the-art performance on a widely-used test set.

Rion Snow; Lucy Vanderwende; Arul Menezes

2006-01-01

181

[False postvoid residual volume diagnosed by videourodynamics].  

PubMed

We present a case report of a young male patient, with a bilateral vesico renal reflux. The urodynamic study findings suggested the possibility of a non-neurogenic bladder-external spincter dissinergya producing a valuable residual volume. After biofeedback treatment, the dissinergia disappeaed, but residual volume persisted. The videourodynamic assessment allowed us the accurate diagnosis of a false residual volume, produced by the voiding of the refluxed urine from the ureters into the bladder. PMID:15666527

Musquera Felip, M; Errando Smet, C; Prados Saavedra, M; Arañó Bertrán, P; Villavicencio Mavrich, H

2004-01-01

182

Infants' Reasoning About Others' False Perceptions  

Microsoft Academic Search

Prior research suggests that children younger than age 3 or 4 do not understand that an agent may be deceived by an object's misleading appearance. The authors asked whether 14.5-month-olds would give evidence in a violation-of-expectation task that they understand that agents may form false perceptions. Infants first watched events in which an agent faced a stuffed skunk and a

Hyun-joo Song; Renée Baillargeon

2008-01-01

183

40 CFR 62.5127 - Identification of plan-Negative Declaration  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Identification of plan-Negative Declaration 62.5127 Section 62...Solid Waste Incinerator (ciswi) Units-Negative Declaration § 62.5127 Identification of planâNegative Declaration May 12, 2005...

2009-07-01

184

40 CFR 62.5127 - Identification of plan-Negative Declaration  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Identification of plan-Negative Declaration 62.5127 Section 62...Solid Waste Incinerator (ciswi) Units-Negative Declaration § 62.5127 Identification of planâNegative Declaration May 12, 2005...

2010-07-01

185

Siblings, language, and false belief in low-income children.  

PubMed

The authors examined the relationship between number of siblings and false belief understanding (FBU) in 94 low-income 4-5-year-olds. Previous research with middle-income children has shown a positive association between number of siblings and FBU. However, it is unclear whether having multiple siblings in low-income families is related to better FBU. Language, specifically vocabulary, was examined as a possible mediator between number of siblings and FBU as several researchers have found that language is causally related to FBU. Contrary to research with middle-income preschoolers, the authors found that number of siblings was negatively related to low-income children's FBU. This relationship was mediated by children's vocabulary skill. Suggestions for why the sibling-FB relationship may differ in low- and middle-income samples are offered. PMID:23991616

Tompkins, Virginia; Farrar, M Jeffrey; Guo, Ying

2013-01-01

186

Apparent resolution enhancement for motion videos  

Microsoft Academic Search

In this work we increase the apparent resolution of videos when viewed on a high-refresh rate display by making use of perceptual properties of the visual system. We achieve this enhancement by exploiting the viewer's natural tendency to track moving objects in videos which causes the screen pixels to be projected at different sub-pixel offsets onto the retina. We estimate

Floraine Berthouzoz; Raanan Fattal

2012-01-01

187

47 CFR 80.1114 - False distress alerts.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false False distress alerts. 80.1114 Section 80.1114...Communications § 80.1114 False distress alerts. The provisions of §§ 80.334 and 80.335 apply to false distress alerts. [68 FR 46980, Aug. 7,...

2010-10-01

188

47 CFR 80.334 - False distress alerts.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false False distress alerts. 80.334 Section 80.334 Telecommunication...and Safety Procedures § 80.334 False distress alerts. A distress alert is false if it was transmitted without any...

2011-10-01

189

47 CFR 80.1114 - False distress alerts.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false False distress alerts. 80.1114 Section 80.1114...Communications § 80.1114 False distress alerts. The provisions of §§ 80.334 and 80.335 apply to false distress alerts. [68 FR 46980, Aug. 7,...

2011-10-01

190

47 CFR 80.334 - False distress alerts.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false False distress alerts. 80.334 Section 80.334 Telecommunication...and Safety Procedures § 80.334 False distress alerts. A distress alert is false if it was transmitted without any...

2012-10-01

191

47 CFR 80.1114 - False distress alerts.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false False distress alerts. 80.1114 Section 80.1114...Communications § 80.1114 False distress alerts. The provisions of §§ 80.334 and 80.335 apply to false distress alerts. [68 FR 46980, Aug. 7,...

2012-10-01

192

47 CFR 80.334 - False distress alerts.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false False distress alerts. 80.334 Section 80.334 Telecommunication...and Safety Procedures § 80.334 False distress alerts. A distress alert is false if it was transmitted without any...

2010-10-01

193

The Neural Correlates of Conceptual and Perceptual False Recognition  

ERIC Educational Resources Information Center

False recognition, broadly defined as a claim to remember something that was not encountered previously, can arise for multiple reasons. For instance, a distinction can be made between conceptual false recognition (i.e., false alarms resulting from semantic or associative similarities between studied and tested items) and perceptual false

Garoff-Eaton, Rachel J.; Kensinger, Elizabeth A.; Schacter, Daniel L.

2007-01-01

194

47 CFR 80.1114 - False distress alerts.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false False distress alerts. 80.1114 Section 80.1114...Communications § 80.1114 False distress alerts. The provisions of §§ 80.334 and 80.335 apply to false distress alerts. [68 FR 46980, Aug. 7,...

2013-10-01

195

47 CFR 80.334 - False distress alerts.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false False distress alerts. 80.334 Section 80.334 Telecommunication...and Safety Procedures § 80.334 False distress alerts. A distress alert is false if it was transmitted without any...

2013-10-01

196

Adults' Memories of Childhood: True and False Reports  

ERIC Educational Resources Information Center

In 3 experiments, the authors examined factors that, according to the source-monitoring framework, might influence false memory formation and true/false memory discernment. In Experiment 1, combined effects of warning and visualization on false childhood memory formation were examined, as were individual differences in true and false childhood…

Qin, Jianjian; Ogle, Christin M.; Goodman, Gail S.

2008-01-01

197

False-positive pregnancy tests following enterocystoplasty.  

PubMed

People with major congenital urological or neurological malformations invariably require bladder reconstruction with enterocystoplasty in early childhood. The improvement of the surgical management of these children has reflected significantly on their life expectancy. As a result, more young people with enterocystoplasty are being transitioned to adolescent clinics where they receive the usual counselling about sexual health and pregnancy risks. However, the possibility of false-positive urinary pregnancy tests in these young women remains an overlooked but essential message. The lack of awareness about this fact can result in significant patient anxiety and the potential for unnecessary interventions as exemplified by the three cases we have encountered. PMID:22082173

Nakhal, R S; Wood, D; Woodhouse, C; Creighton, S M

2012-02-01

198

False discovery rates in spectral identification.  

PubMed

Automated database search engines are one of the fundamental engines of high-throughput proteomics enabling daily identifications of hundreds of thousands of peptides and proteins from tandem mass (MS/MS) spectrometry data. Nevertheless, this automation also makes it humanly impossible to manually validate the vast lists of resulting identifications from such high-throughput searches. This challenge is usually addressed by using a Target-Decoy Approach (TDA) to impose an empirical False Discovery Rate (FDR) at a pre-determined threshold x% with the expectation that at most x% of the returned identifications would be false positives. But despite the fundamental importance of FDR estimates in ensuring the utility of large lists of identifications, there is surprisingly little consensus on exactly how TDA should be applied to minimize the chances of biased FDR estimates. In fact, since less rigorous TDA/FDR estimates tend to result in more identifications (at higher 'true' FDR), there is often little incentive to enforce strict TDA/FDR procedures in studies where the major metric of success is the size of the list of identifications and there are no follow up studies imposing hard cost constraints on the number of reported false positives. Here we address the problem of the accuracy of TDA estimates of empirical FDR. Using MS/MS spectra from samples where we were able to define a factual FDR estimator of 'true' FDR we evaluate several popular variants of the TDA procedure in a variety of database search contexts. We show that the fraction of false identifications can sometimes be over 10× higher than reported and may be unavoidably high for certain types of searches. In addition, we further report that the two-pass search strategy seems the most promising database search strategy. While unavoidably constrained by the particulars of any specific evaluation dataset, our observations support a series of recommendations towards maximizing the number of resulting identifications while controlling database searches with robust and reproducible TDA estimation of empirical FDR. PMID:23176207

Jeong, Kyowon; Kim, Sangtae; Bandeira, Nuno

2012-01-01

199

False discovery rates in spectral identification  

PubMed Central

Automated database search engines are one of the fundamental engines of high-throughput proteomics enabling daily identifications of hundreds of thousands of peptides and proteins from tandem mass (MS/MS) spectrometry data. Nevertheless, this automation also makes it humanly impossible to manually validate the vast lists of resulting identifications from such high-throughput searches. This challenge is usually addressed by using a Target-Decoy Approach (TDA) to impose an empirical False Discovery Rate (FDR) at a pre-determined threshold x% with the expectation that at most x% of the returned identifications would be false positives. But despite the fundamental importance of FDR estimates in ensuring the utility of large lists of identifications, there is surprisingly little consensus on exactly how TDA should be applied to minimize the chances of biased FDR estimates. In fact, since less rigorous TDA/FDR estimates tend to result in more identifications (at higher 'true' FDR), there is often little incentive to enforce strict TDA/FDR procedures in studies where the major metric of success is the size of the list of identifications and there are no follow up studies imposing hard cost constraints on the number of reported false positives. Here we address the problem of the accuracy of TDA estimates of empirical FDR. Using MS/MS spectra from samples where we were able to define a factual FDR estimator of 'true' FDR we evaluate several popular variants of the TDA procedure in a variety of database search contexts. We show that the fraction of false identifications can sometimes be over 10× higher than reported and may be unavoidably high for certain types of searches. In addition, we further report that the two-pass search strategy seems the most promising database search strategy. While unavoidably constrained by the particulars of any specific evaluation dataset, our observations support a series of recommendations towards maximizing the number of resulting identifications while controlling database searches with robust and reproducible TDA estimation of empirical FDR.

2012-01-01

200

Apparent linear attenuation coefficients in phase contrast X-ray tomography  

NASA Astrophysics Data System (ADS)

In the inline phase contrast X-ray tomography the reconstructed apparent linear attenuation coefficient values may be greatly larger than sample's linear attenuation coefficients or even be negative. In this work we present a general formula to quantitatively relate the apparent linear attenuation coefficient values in cone-beam phase contrast tomography to sample's linear attenuation coefficients and refractive indices. This formula overcomes the gross inaccuracy of the existing formula in the literature in analyzing high-resolution phase contrast tomography, and it will be useful for correctly interpreting and quantifying the apparent linear attenuation coefficients in cone-beam X-ray phase contrast tomography.

Yan, Aimin; Wu, Xizeng

2011-08-01

201

Inhibition and facilitation of apparent motion by real motion.  

PubMed

Observers viewed a CRT display which contained both real and apparent motion. When the apparent motion was in the same direction as the real motion, the strength of the apparent motion was enhanced. Real motion in the opposite direction completely cancelled apparent motion. However, the appearance of the real motion was not affected by apparent motion. PMID:6636545

Green, M

1983-01-01

202

Does secotioid inertia drive the evolution of false-truffles?  

PubMed

Secotioid inertia is a model implemented to explain the prevalence of highly derived false-truffles with no obvious connection to the Homobasidiomycetes. The model accommodates the apparent lack of epigeous sister taxa for some highly derived hypogeous lineages by assuming that gasteromycetation in some fungi leads to the extinction of their epigeous sister population. The derived state of some hypogeous lineages suggests that they arose early in the evolution of Homobasidiomycetes and that those groups were subject to conditions that favoured hypogeous lineages such that the hypogeous fruit body form became the predominant form for some lineages. The directional selection component of secotioid inertia, termed secotioid drive, led to the extinction of their epigeous sister taxon. Morphological and molecular data from Russulaceae are used to model the evolutionary stages of secotioid inertia. The resulting phylogenetic results are compared with data from the order Leucogastrales, and the genus Destuntzia. The implications of secotioid drive are discussed with reference to gasteromycete phylogenetics, evolution, and conservation. Specifically, secotioid inertia can be used to account for reversals in fruit body morphology and instability in mycorrhizal formation. PMID:17964769

Albee-Scott, Steven Robert

2007-09-01

203

Apparent extended body motions in depth  

NASA Technical Reports Server (NTRS)

Five experiments were designed to investigate the influence of three-dimensional (3-D) orientation change on apparent motion. Projections of an orientation-specific 3-D object were sequentially flashed in different locations and at different orientations. Such an occurrence could be resolved by perceiving a rotational motion in depth around an axis external to the object. Consistent with this proposal, it was found that observers perceived curved paths in depth. Although the magnitude of perceived trajectory curvature often fell short of that required for rotational motions in depth (3-D circularity), judgments of the slant of the virtual plane on which apparent motions occurred were quite close to the predictions of a model that proposes circular paths in depth.

Hecht, Heiko; Proffitt, Dennis R.

1991-01-01

204

Developmental Reversals in False Memory: Effects of Emotional Valence and Arousal  

PubMed Central

Do the emotional valence and arousal of events distort children’s memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can be manipulated factorially. False memories increased with age for unpresented semantic associates of word lists, and net accuracy (the ratio of true memory to total memory) decreased with age. These surprising developmental trends were more pronounced for negatively-valenced materials than for positively-valenced materials, they were more pronounced for high-arousal materials than for low-arousal materials, and developmental increases in the effects of arousal were small in comparison to developmental increases in the effects of valence. These findings have ramifications for legal applications of false-memory research: Materials that share the emotional hallmark of crimes (events that are negatively valenced and arousing) produced the largest age increases in false memory and the largest age declines in net accuracy.

Brainerd, C. J.; Holliday, R. E.; Reyna, V. F.; Yang, Y.; Toglia, M. P.

2010-01-01

205

Apparent oxygen solubility in refractory carbides  

Microsoft Academic Search

The occurrence of an apparent solubility of oxygen in polycrystalline NbC, TiC, VC and ZrC is discussed. This is shown by experiments in which the oxygen consumed by the sample is directly measured as a function of temperature in an argon stream at 1.6 bar (rel) where the oxygen partial pressure was as low as 0.8 Pa. The parameter ?,

D. Gozzi; M. Montozzi; P. L. Cignini

1999-01-01

206

Comment: An Apparent Controversy in Auroral Physics  

NASA Astrophysics Data System (ADS)

In his article ``A turning point in auroral physics,'' Bryant argued against what he called the `standard' theory of auroral acceleration, according to which the electrons ``gain their energy from static electric fields,'' and offered wave acceleration as an alternative. Because of the importance of the process, not only for the aurora borealis but also for other cosmic plasmas, a clarification of this apparent controversy seems to be in place.

Haerendel, Gerhard

2007-03-01

207

The Apparent Thermal Conductivity of Pozzolana Concrete  

NASA Astrophysics Data System (ADS)

The recent development of some lightweight construction materials, such as light concrete, can play an important role as an insulator, while maintaining sufficient levels of mechanical performance. The quality of insulation to provide depends on the climate, the exposure of the walls and also the materials used in the construction. The choice of a material to be used as an insulator, obviously, depends on its availability and its cost. This is a study of natural pozzolanas as basic components in building materials. It is intended to highlight their thermal advantage. It is economically advantageous to use pozzolana in substitution for a portion of the clinker as hydraulically active additions, as well as in compositions of lightweight concretes in the form of pozzolanic aggregate mixtures, which provide mechanical strengths that comply with current standards. A theoretical study is conducted on the apparent thermal conductivity of building materials, namely concrete containing pozzolana. Thermal modeling, apparent to that commonly used for porous materials, has been applied to pozzolana concrete. Experimental results on measurements of the apparent thermal conductivity of pozzolana concrete are reported in this study, using an approach that considers that concrete is composed of two solid ingredients, a binding matrix (hydrated cement paste) and all aggregates. A second comparative theoretical approach is used for the case where concrete consists of a solid phase and a fluid phase (air).

Bessenouci, M. Z.; Triki, N. E. Bibi; Khelladi, S.; Draoui, B.; Abene, A.

208

Apparent exchange rate mapping with diffusion MRI.  

PubMed

Water exchange through the cell membranes is an important feature of cells and tissues. The rate of exchange is determined by factors such as membrane lipid composition and organization, as well as the type and activity of aquaporins. A method for noninvasively estimating the rate of water exchange would be useful for characterizing pathological conditions, e.g., tumors, multiple sclerosis, and ischemic stroke, expected to be associated with a change of the membrane barrier properties. This study describes the filter exchange imaging method for determining the rate of water exchange between sites having different apparent diffusion coefficients. The method is based on the filter-exchange pulsed gradient spin-echo NMR spectroscopy experiment, which is here modified to be compatible with the constraints of clinical MR scanners. The data is analyzed using a model-free approach yielding maps of the apparent exchange rate, here being introduced in analogy with the concept of the apparent diffusion coefficient. Proof-of-principle experiments are performed on microimaging and whole-body clinical scanners using yeast suspension phantoms. The limitations and appropriate experimental conditions are examined. The results demonstrate that filter exchange imaging is a fast and reliable method for characterizing exchange, and that it has the potential to become a powerful diagnostic tool. PMID:21446037

Lasi?, Samo; Nilsson, Markus; Lätt, Jimmy; Ståhlberg, Freddy; Topgaard, Daniel

2011-08-01

209

Apparent Solar Tornado-Like Prominences  

NASA Astrophysics Data System (ADS)

Recent high-resolution observations from the Solar Dynamics Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado-like prominences. This class of prominences was first introduced by Pettit ( Astrophys. J. 76, 9, 1932), who studied them over many years. Observations of tornado prominences similar to the ones seen by SDO had already been documented by Secchi ( Le Soleil, 1877). High-resolution and high-cadence multiwavelength data obtained by SDO reveal that the tornado-like appearance of these prominences is mainly an illusion due to projection effects. We discuss two different cases where prominences on the limb might appear to have a tornado-like behavior. One case of apparent vortical motions in prominence spines and barbs arises from the (mostly) 2D counterstreaming plasma motion along the prominence spine and barbs together with oscillations along individual threads. The other case of apparent rotational motion is observed in a prominence cavity and results from the 3D plasma motion along the writhed magnetic fields inside and along the prominence cavity as seen projected on the limb. Thus, the "tornado" impression results either from counterstreaming and oscillations or from the projection on the plane of the sky of plasma motion along magnetic-field lines, rather than from a true vortical motion around an (apparent) vertical or horizontal axis. We discuss the link between tornado-like prominences, filament barbs, and photospheric vortices at their base.

Panasenco, Olga; Martin, Sara F.; Velli, Marco

2014-02-01

210

Spirit Scans Winter Haven (False Color)  

NASA Technical Reports Server (NTRS)

At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand.

This view is a false-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

2006-01-01

211

Two Holes in 'Wooly Patch' (False Color)  

NASA Technical Reports Server (NTRS)

The rock abrasion tool on NASA's Mars Exploration Rover Spirit ground two holes in a relatively soft rock called 'Wooly Patch' near the base of the 'Columbia Hills' inside Gusev Crater on Mars. This false-color image from the panoramic camera was taken on sol 200 (July 25, 2004) and generated using the camera's 750-, 530-, and 430-nanometer filters. It highlights the material ground up by the rock abrasion tool, grayish-blue in appearance in this image. The color of the material excavated suggests the interior of the rock contains iron minerals that are less oxidized than the dust or possibly weathered coating on the exterior of the rock. Scientists speculate that this relatively soft rock (compared to others analyzed by Spirit) may have been modified by water. Small cracks in the surface outside the drill holes may be the result of interactions with water-rich fluids.

2004-01-01

212

Some comments on GMTI false alarm rate  

NASA Astrophysics Data System (ADS)

A typical Ground Moving Target Indicator (GMTI) radar specification includes the parameters Probability of Detection (PD) - typically on the order of 0.85, and False Alarm Rate (FAR) - typically on the order of 0.1 Hz. The PD is normally associated with a particular target 'size', such as Radar Cross Section (RCS) with perhaps some statistical description (e.g. Swerling number). However, the concept of FAR is embodied at a fundamental level in the detection process, which traditionally employs a Constant-FAR (CFAR) detector to set thresholds for initial decisions on whether a target is present or not. While useful, such a metric for radar specification and system comparison is not without some serious shortcomings. In particular, when comparing FAR across various radar systems, some degree of normalization needs to occur to account for perhaps swath width and scan rates. This in turn suggests some useful testing strategies.

Doerry, A. W.

2011-05-01

213

Opportunity View of 'Gilbert' Layer (False Color)  

NASA Technical Reports Server (NTRS)

This view from NASA's Mars Exploration Rover Opportunity shows bedock within a stratigraphic layer informally named 'Gilbert,' which is the rover's next target after completing an examination of three stratigtaphic layers forming a bright band around the inside of Victoria Crater. The rover will descend deeper into the crater to reach the Gilbert layer.

Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:30 p.m. during the rover's 1,429th Martian day, of sol (Jan. 31, 2008).

This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

2008-01-01

214

Opportunity View of 'Lyell' Layer (False Color)  

NASA Technical Reports Server (NTRS)

This view from NASA's Mars Exploration Rover Opportunity shows bedrock within a stratigraphic layer informally named 'Lyell,' which is the lowermost of three layers the rover has examined at a bright band around the inside of Victoria Crater.

Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:21 p.m. during the rover's 1,433rd Martian day, of sol (Feb. 4, 2008).

This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

2008-01-01

215

View from Spirit's Overwintering Position (False Color)  

NASA Technical Reports Server (NTRS)

NASA's Mars Exploration Rover Spirit has this view northward from the position at the north edge of the 'Home Plate' plateau where the rover will spend its third Martian winter.

Husband Hill is on the horizon. The dark area in the middle distance is 'El Dorado' sand dune field.

Spirit used its panoramic camera (Pancam) to capture this image during the rover's 1,448th Martian day, of sol (Jan. 29, 2008).

This view combines separate images taken through the Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

2008-01-01

216

Impact of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography Before and After Definitive Radiation Therapy in Patients With Apparently Solitary Plasmacytoma  

SciTech Connect

Purpose: To evaluate the impact of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) on management of patients with apparently isolated plasmacytoma. Methods and Materials: Twenty-one patients with apparently solitary plasmacytoma who underwent FDG-PET for staging or restaging were identified from a central PET database. They were either candidates for or had received definitive radiation therapy (RT). Results: Seventeen patients had initial staging scans for bone (n = 11) or soft tissue (n = 6) plasmacytomas, and 11 had PET scans after RT. Only 1 of 14 known untreated sites of plasmacytoma was not identified on staging PET (lesion sensitivity = 93%). Three plasmacytomas were excised before PET. Staging PET influenced management in 6 of 17 patients (35%) by showing multiple myeloma (n = 1), discouraging RT after complete resection (n = 1), excluding plasmacytoma at a second site (n = 1), by increasing RT fields (n = 2), or by suggesting sarcoidosis (n = 1). Fifteen of 17 patients with initial staging PET scans received definitive RT. Restaging PET scans after RT showed complete metabolic response in 8 of 11 cases and progressive disease in 2. Two patients with either no response or partial metabolic response had late responses. Staging sestamibi and PET scans were concordant in five of six occasions (one sestamibi scan was false negative). Conclusions: FDG-PET has value for staging and RT planning in plasmacytoma and potentially could have a role in response-assessment after RT. Slow resolution of FDG uptake posttreatment does not necessarily imply an adverse prognosis.

Kim, Paul J. [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, CA (United States); Hicks, Rodney J. [Centre for Molecular Imaging and Translational Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Wirth, Andrew; Ryan, Gail [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Seymour, John F.; Prince, H. Miles [Department of Haematology/Medical Oncology, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne, Victoria (Australia); Mac Manus, Michael P. [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia)], E-mail: michael.macmanus@petermac.org

2009-07-01

217

Reducing False Negative Reads in RFID Data Streams Using an Adaptive Sliding-Window Approach  

PubMed Central

Unreliability of the data streams generated by RFID readers is among the primary factors which limit the widespread adoption of the RFID technology. RFID data cleaning is, therefore, an essential task in the RFID middleware systems in order to reduce reading errors, and to allow these data streams to be used to make a correct interpretation and analysis of the physical world they are representing. In this paper we propose an adaptive sliding-window based approach called WSTD which is capable of efficiently coping with both environmental variation and tag dynamics. Our experimental results demonstrate the efficacy of the proposed approach.

Massawe, Libe Valentine; Kinyua, Johnson D. M.; Vermaak, Herman

2012-01-01

218

True versus False Positives and Negatives on the "Modified Checklist for Autism in Toddlers"  

ERIC Educational Resources Information Center

Given the importance of early intervention services for children with autism spectrum disorders (ASD), early diagnosis of children is critical. At present, several ASD screeners exist for young children, with the "Modified Checklist for Autism in Toddlers" ("M-CHAT") being one of the most widely researched. While the "M-CHAT" has good sensitivity…

Matson, Johnny L.; Kozlowski, Alison M.; Fitzgerald, Mary E.; Sipes, Megan

2013-01-01

219

Preventing false negatives with high-resolution mass spectrometry: the benzophenone case.  

PubMed

Benzophenone (BP) is one of the many contaminants reported as present in foodstuffs due to its migration from food packaging materials. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is acknowledged in the literature as the method of choice for this analysis. However, cases have been reported where the use of this methodology was insufficient to unambiguously confirm the presence of a contaminant. In previous work performed by the authors, the unequivocal identification of BP in packaged foods was not possible even when monitoring two m/z transitions (precursor ion - product ion), since ion ratio errors higher than 20% were obtained. In order to overcome this analytical problem a fast, sensitive and selective liquid chromatography/high-resolution mass spectrometry (LC/HRMS) methodology has been developed and applied to the analysis of BP in packaged foods. A direct comparison between LC/HRMS and LC/MS/MS data indicated better selectivity when working with LC/HRMS at a resolving power of 50,000 FWHM (full width at half maximum) than when monitoring two m/z transitions by LC/MS/MS. The resolving power used enabled the detection and identification of Harman as the compound impeding the confirmation of BP by LC-MS/MS. Similar quantitative results were obtained by an Orbitrap mass analyser (Exactive™) and a triple quadrupole mass analyser (TSQ Quantum Ultra AM™). PMID:21953972

Gallart-Ayala, H; Nuñez, O; Moyano, E; Galceran, M T; Martins, C P B

2011-10-30

220

Apparent Geocenter Variations from IGS Analysis  

NASA Astrophysics Data System (ADS)

Natural Resources Canada's (NRCan) Geodetic Survey Division (GSD), on behalf of the International GPS Service (IGS) and its Reference Frame Working Group, combines a consistent set of station coordinates, velocities, Earth Rotation Parameters (ERP) and apparent geocenter to produce the IGS official station position/ERP solutions in the Software Independent Exchange (SINEX) format The weekly Analysis Centers (AC) solutions include estimates of weekly station coordinates, apparent geocenter positions and daily ERPs. All the AC products are required to be in a consistent reference frame. The combination of station coordinates originating from different ACs involves removing all available constraints and re-scaling the covariance information. The weekly combination generally includes estimates of coordinates for 120 to 140 globally distributed stations. While the cumulative solution currently includes approximately 280 stations, about 215 of them have complete information and reliable velocity estimates. The IGS combined products are required to be consistent with the most recent realization of ITRF (currently ITRF97, soon in ITRF2000). This is done by transforming the weekly and cumulative solutions, respectively using 7 and 14 Helmert transformation parameters (3 translations, 3 rotations, 1 scale and their respective rates). The transformation parameters are determined from a subset of 51 high quality, globally distributed and generally collocated (with other space techniques) stations, also known as Reference Frame (RF) stations. The weekly estimated IGS apparent geocenter for the period between 99/08/01 (Wk 1012) and 01/08/04 (Wk 1025) has been analyzed. The apparent X, Y and Z geocenter components were estimated with respect to the realization of ITRF97. The estimated weekly geocenter positions relied on COD, ESA and JPL SINEX solutions for the period of interest. The formal error for the weekly geocenter is about 6-8mm for the XY components and 8-10mm for the Z component. The average geocenter estimate for that period are 2mm, 4mm and -17.5 mm for the X, Y and Z components. A spectral analysis was done on each component of the weekly estimate. A bias and a drift were removed from each component of the time series. The spectral analysis on each axis showed the presence of a significant annual period with amplitude of about 4mm, 6mm and 7mm. Semi annual periods were also found for each axis with amplitude of about 3.5mm 4.5mm and 4.0mm. The position and velocity of the origin of the proposed IGS realization of ITRF2000 with respect to ITRF97 was also determined. It was estimated from the IGS97 and (proposed) IGS2000 realizations of ITRF using 50 common stations. The results indicate that with IGS2000 the Y and Z components of the IGS apparent geocenter would agree better with the IGS2000 origin. This also suggest an improved agreement between the SLR determination of the geocenter, which defines the origin for ITRF2000 and the IGS combined apparent geocenter. The presentation will show details of the analysis.

Ferland, R.

2001-12-01

221

On the apparent randomness of substorm onset  

SciTech Connect

The onset of the expansion phase of substorms is currently unpredictable, that unpredictability being related to the nonlinear nature of the solar wind - magnetosphere interaction. Using the mathematics of catastrophe theory it is possible to describe the substorm phenomenon in terms of a fundamental singularity of the solar wind - magnetosphere interaction. The apparently random nature of substorm onset can then be explained as the result of an unfolding of the singularity of the cusp catastrophe which is in principle predictable. Substorm expansions are triggered when two features of the solar wind - magnetosphere interaction are critically functionally related.

Lewis, Z.V. (Imperial Coll., London (United Kingdom))

1991-08-01

222

[Disseminated cryptococcosis in an apparently immunocompetent patient].  

PubMed

Cryptococcal infections occur frequently in immunocompromised patients particularly in the context of AIDS, lymphomas and following immunosuppression for organ transplant recipients. In these contexts the infection is readily considered and diagnosis straightforward. The diagnosis is rarer and thus less likely to be considered in immunocompetent patients which can lead to late diagnosis and delay in initiation of therapy. We report the case of disseminated cryptococcosis with endobronchial, cutaneous, bone and meningeal involvement in an apparently immunocompetent patient. Before antifungal treatment could be initiated the patient died of cerebral complications. PMID:19953023

El Ouazzani, H; Achachi, L; Belkhiri, S; El Ftouh, M; El Fassy Fihry, M-T

2009-09-01

223

An Apparent Relationship Between Locoism and Lathyrism  

PubMed Central

An apparent relationship between locoism and lathyrism was investigated. Similarities reported in the literature in botanical relationship, signs produced in affected animals, and chemical characteristics were noted. It was demonstrated that the known lathyrogens, aminoacetonitrile and ?, ?-diaminobutyric acid, as well as an extract from the loco plant (expected to contain lathyrogens if present in the plant) produced many of the abortive, teratogenic and neurologic effects and signs evident in animals in true locoism. Preliminary assay of extracts from the plant suggested the presence of lathyrogens in the loco plant. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 5.Fig. 6.Fig. 7.

Keeler, Richard F.; James, Lynn F.; Binns, Wayne; Shupe, James L.

1967-01-01

224

Using the Ancient Method of False Position to Find Solutions  

ERIC Educational Resources Information Center

Several activities that are based on the ancient method of false position, also called false assumption, are presented in this article as a way to motivate students to find the solution of literal equations in beginning algebra.

Edwards, Thomas G.

2008-01-01

225

42 CFR 21.23 - False statements as disqualification.  

Code of Federal Regulations, 2012 CFR

... COMMISSIONED OFFICERS Appointment § 21.23 False statements as disqualification. Willfully false statements shall be cause for rejection of the application or, as provided in subpart N of this part, for...

2012-10-01

226

Latent and apparent image quality metrics  

NASA Astrophysics Data System (ADS)

Measures of image quality are presented here that have been developed to assess both the immediate quality of an image and the potential at intermediate points in an imaging chain for enhanced image quality. The original intent of the metric(s) was to provide an optimand for interpolator design, and the metrics have subsequently been used for a number of differential image quality analyses and imaging system component designs. The metrics presented are of the same general form as the National Imagery Interpretability Rating Scale (NIIRS), representing quality as the base-2 logarithm of linear resolution, so that one unit of differential quality represents a doubling or halving of the resolution of imagery. Analysis of a simple imaging chain is presented in terms of the metrics, with conclusions regarding interpolator design, consistency of the latent and apparent image quality metrics, and the relationship between interpolator and convolution kernel design in a system where both are present. Among the principal results are an optimized division of labor between interpolators and Modulation Transfer Function Correction (MTFC) filters, consistency of the analytical latent and apparent image quality metrics with each other and with visually optimized aim curves, and an introduction to sharpening interpolator design methodology.

Miettinen, Kristo S.

2002-07-01

227

Apparent and true enantioselectivity in enantioseparations.  

PubMed

The separation factor of two compounds in chromatography is the ratio of their equilibrium constants or retention factors. This parameter is universally employed to investigate their resolution and to optimize the experimental conditions of their analysis. In enantioseparations, the situation is more complex because there is a mixed retention mechanism. The retention factor is the sum of two contributions, one enantioselective, the other nonselective. Although both contribute to retention, the latter being identical for the two enantiomers and does not contribute to their separation. We show how these two contributions can be measured and how it becomes necessary to distinguish between the apparent, alpha(app), and the true, alpha(true), separation factors. The existence of nonselective sites is responsible for alpha(app) being less than alpha(true). Depending on the difference between these two factors, the more effective approach to improve a separation is either to increase the enantioselectivity or to reduce the nonselective interactions. Practical applications to separations of different beta-blockers on cellobiohydrolase are discussed. The apparent enantioselectivity of alprenolol is larger and increases faster with increasing pH than that of the more hydrophobic propranolol, in spite of the importance of hydrophobic interactions in the enantioselective mechanism. These two unexpected properties are discussed and explained. PMID:10861955

Götmar, G; Fornstedt, T; Guiochon, G

2000-07-01

228

On the prefactor in false vacuum decay  

NASA Astrophysics Data System (ADS)

This paper gives a survey of recent work in collaboration with G Dunne concerning a new method for computing determinants in quantum field-theoretic applications, using angular momentum cut-off regularization and renormalization. This method is generally applicable to the situation of computing the quantum fluctuations about a classical configuration that has a symmetry allowing the fluctuation operator to be radially separable. There are many such cases of interest in quantum field theory. Here I describe the case of the false vacuum decay rate in a self-interacting scalar field theory modelling the process of nucleation in a four-dimensional spacetime. The rate prefactor involves quantum fluctuations about the classical bounce solution, which is O(4) symmetric. The computational method is based on the Gelfand-Yaglom approach to determinants of ordinary differential operators, suitably extended to higher dimensions using angular momentum cut-off regularization. I also present a simple new formula for the zero-mode contribution to the fluctuation prefactor, expressed entirely in terms of the asymptotic behaviour of the classical bounce solution.

Min, Hyunsoo

2006-05-01

229

'Endurance Crater's' Dazzling Dunes (false-color)  

NASA Technical Reports Server (NTRS)

As NASA's Mars Exploration Rover Opportunity creeps farther into 'Endurance Crater,' the dune field on the crater floor appears even more dramatic. This false-color image taken by the rover's panoramic camera shows that the dune crests have accumulated more dust than the flanks of the dunes and the flat surfaces between them. Also evident is a 'blue' tint on the flat surfaces as compared to the dune flanks. This results from the presence of the hematite-containing spherules ('blueberries') that accumulate on the flat surfaces.

Sinuous tendrils of sand less than 1 meter (3.3 feet) high extend from the main dune field toward the rover. Scientists hope to send the rover down to one of these tendrils in an effort to learn more about the characteristics of the dunes. Dunes are a common feature across the surface of Mars, and knowledge gleaned from investigating the Endurance dunes close-up may apply to similar dunes elsewhere.

Before the rover heads down to the dunes, rover drivers must first establish whether the slippery slope that leads to them is firm enough to ensure a successful drive back out of the crater. Otherwise, such hazards might make the dune field a true sand trap.

2004-01-01

230

Peering at Pesky 'Jammerbugt' (False Color)  

NASA Technical Reports Server (NTRS)

This false-color image was generated from images obtained by NASA's Mars Exploration Rover Opportunity on sol 842 (June 7, 2006) using the panoramic camera's 750-nanometer, 530-nanomter, and 430-nanometer filters.

As winter has descended over Meridiani Planum, the availability of solar power for the rovers has diminished greatly. One consequence of less power for Opportunity is that there are fewer telecommunications links via the orbiting Mars Odyssey spacecraft because the rover needs to use the 'deep sleep' mode overnight to conserve energy. As a result, images that are not needed specifically to help plan the next sol of operations often stay onboard for much longer time than the science team has been used to. For example, on sol 833 Opportunity became embedded within an unexpectedly deep and very fine-grained ripple, named 'Jammerbugt' by the operations team, and spent the next eight sols (834-841) extricating itself.

A series of images from the hazard avoidance camera were quickly returned because they were needed to help plan the drive sequences. However, once the rover was free from the ripple, the science team commanded these panoramic camera image mosaics on sol 842 to show complete coverage of the wheel tracks that were left by Opportunity during the extraction process. The images are of great scientific value but were not critical for planning operations. Accordingly, they were not fully downlinked until sol 864 (June 29, 2006), about three weeks after they were obtained.

2006-01-01

231

The False Security of Blind Dates  

PubMed Central

Background The reuse of clinical data for research purposes requires methods for the protection of personal privacy. One general approach is the removal of personal identifiers from the data. A frequent part of this anonymization process is the removal of times and dates, which we refer to as “chrononymization.” While this step can make the association with identified data (such as public information or a small sample of patient information) more difficult, it comes at a cost to the usefulness of the data for research. Objectives We sought to determine whether removal of dates from common laboratory test panels offers any advantage in protecting such data from re-identification. Methods We obtained a set of results for 5.9 million laboratory panels from the National Institutes of Health’s (NIH) Biomedical Translational Research Information System (BTRIS), selected a random set of 20,000 panels from the larger source sets, and then identified all matches between the sets. Results We found that while removal of dates could hinder the re-identification of a single test result, such removal had almost no effect when entire panels were used. Conclusions Our results suggest that reliance on chrononymization provides a false sense of security for the protection of laboratory test results. As a result of this study, the NIH has chosen to rely on policy solutions, such as strong data use agreements, rather than removal of dates when reusing clinical data for research purposes.

Cimino, J.J.

2012-01-01

232

Deep Hole in 'Clovis' (False Color)  

NASA Technical Reports Server (NTRS)

At a rock called 'Clovis,' the rock abrasion tool on NASA's Mars Exploration Rover Spirit cut a 9-millimeter (0.35-inch) hole during the rover's 216th martian day, or sol (Aug. 11, 2004). The hole is the deepest drilled in a rock on Mars so far. This false color view was made from images taken by Spirit's panoramic camera on sol 226 (Aug. 21, 2004) at around 12:50 p.m. local true solar time -- early afternoon in Gusev Crater on Mars. To the right is a 'brush flower' of circles produced by scrubbing the surface of the rock with the abrasion tool's wire brush. Scientists used rover's Moessbauer spectrometer and alpha particle X-ray spectrometer to look for iron-bearing minerals and determine the elemental chemical composition of the rock. This composite combines images taken with the camera's 750-, 530-, and 430-nanometer filters. The grayish-blue hue in this image suggests that the interior of the rock contains iron minerals that are less oxidized than minerals on the surface. The diameter of the hole cut into the rock is 4.5 centimeters (1.8 inches).

2004-01-01

233

Band of Bright Rock (False Color)  

NASA Technical Reports Server (NTRS)

This image captured by NASA's Mars Exploration Rover Opportunity shows 'Cape St. Vincent,' one of the many promontories that jut out from the walls of Victoria Crater, Mars. The material at the top of the promontory consists of loose, jumbled rock, then a bit further down into the crater, abruptly transitions to solid bedrock. This transition point is marked by a bright band of rock, visible around the entire crater.

Scientists say this bright band represents what used to be the surface of Mars just before an impact formed Victoria Crater. After Opportunity begins to descend into the crater in early July 2007, it will examine the band carefully at an accessible location with a gentle slope. These investigations might help determine if the band's brighter appearance is the result of ancient interactions with the Martian atmosphere.

This image was taken by Opportunity's panoramic camera on sol 1167 (May 6, 2007). It is presented in false color to accentuate differences in surface materials.

2007-01-01

234

Compelling Untruths: Content Borrowing and Vivid False Memories  

ERIC Educational Resources Information Center

False memories are sometimes accompanied by surprisingly vivid experiential detail that makes them difficult to distinguish from actual memories. Such strikingly real false memories may be produced by a process called content borrowing in which details from presented items are errantly borrowed to corroborate the occurrence of the false memory…

Lampinen, James Michael; Meier, Christopher R.; Arnal, Jack D.; Leding, Juliana K.

2005-01-01

235

Lexical Association and False Memory for Words in Two Cultures  

ERIC Educational Resources Information Center

This study examined the relationship between language experience and false memory produced by the DRM paradigm. The word lists used in Stadler, et al. (Memory & Cognition, 27, 494-500, 1999) were first translated into Chinese. False recall and false recognition for critical non-presented targets were then tested on a group of Chinese users. The…

Lee, Yuh-Shiow; Chiang, Wen-Chi; Hung, Hsu-Ching

2008-01-01

236

Validity and Reliability of True-False Tests.  

ERIC Educational Resources Information Center

A model of examinee behavior was used to generate hypotheses about the operation of true-false scores. Confirmation of hypotheses supported the contention that true-false scores contain an error component that makes these tests less reliable than multiple-choice tests. Examinee response style may invalidate a total true-false score. (Author/DWH)

Grosse, Martin E.; Wright, Benjamin D.

1985-01-01

237

Interaction of sleep and emotional content on the production of false memories.  

PubMed

Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM) paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep's effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list's "gist." Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay) did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details. PMID:23145159

McKeon, Shannon; Pace-Schott, Edward F; Spencer, Rebecca M C

2012-01-01

238

Proactive and retroactive effects of negative suggestion.  

PubMed

The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false discrimination was evaluated via multiple-choice tests. Negative suggestion, defined as poorer performance on interference items than noninterference (control) items, consistently occurred when the wrong information followed the correct information (RI) but not when it preceded the correct information (PI). These effects did not change as a function of retention interval (immediate, 1 week, or 3 weeks) or number of incorrect alternatives (1 or 3). Implications of this outcome for experiencing incorrect information in both academic and nonacademic situations are considered. PMID:17087580

Brown, Alan S; Brown, Christine M; Mosbacher, Joy L; Dryden, W Erich

2006-11-01

239

The effect of false memory on temporal perception.  

PubMed

This study examined the effect of false memory on temporal perception. The Deese-Roediger-McDermott (DRM) paradigm, which elicits false recognition of a nonpresented word, was used to determine whether the perceived duration of falsely remembered words was longer than that for control words. The study results revealed that the perceived duration for falsely recognized words was longer than that for correctly rejected words. This is the first study to show the effect of false memory on temporal perception and suggests that temporal perception can be affected by conceptual fluency without any perceptual repetition. PMID:16821048

Ono, Fuminori; Kawahara, Jun-ichiro

2008-01-01

240

Natural and False Color Views of Europa  

NASA Technical Reports Server (NTRS)

This image shows two views of the trailing hemisphere of Jupiter's ice-covered satellite, Europa. The left image shows the approximate natural color appearance of Europa. The image on the right is a false-color composite version combining violet, green and infrared images to enhance color differences in the predominantly water-ice crust of Europa. Dark brown areas represent rocky material derived from the interior, implanted by impact, or from a combination of interior and exterior sources. Bright plains in the polar areas (top and bottom) are shown in tones of blue to distinguish possibly coarse-grained ice (dark blue) from fine-grained ice (light blue). Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. The bright feature containing a central dark spot in the lower third of the image is a young impact crater some 50 kilometers (31 miles) in diameter. This crater has been provisionally named 'Pwyll' for the Celtic god of the underworld.

Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth's moon. This image was taken on September 7, 1996, at a range of 677,000 kilometers (417,900 miles) by the solid state imaging television camera onboard the Galileo spacecraft during its second orbit around Jupiter. The image was processed by Deutsche Forschungsanstalt fuer Luftund Raumfahrt e.V., Berlin, Germany.

The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo

1996-01-01

241

Computing the apparent centroid of radar targets  

SciTech Connect

A high-frequency multibounce radar scattering code was used as a simulation platform for demonstrating an algorithm to compute the ARC of specific radar targets. To illustrate this simulation process, several targets models were used. Simulation results for a sphere model were used to determine the errors of approximation associated with the simulation; verifying the process. The severity of glint induced tracking errors was also illustrated using a model of an F-15 aircraft. It was shown, in a deterministic manner, that the ARC of a target can fall well outside its physical extent. Finally, the apparent radar centroid simulation based on a ray casting procedure is well suited for use on most massively parallel computing platforms and could lead to the development of a near real-time radar tracking simulation for applications such as endgame fuzing, survivability, and vulnerability analyses using specific radar targets and fuze algorithms.

Lee, C.E.

1996-12-31

242

Optimal False Discovery Rate Control for Dependent Data  

PubMed Central

This paper considers the problem of optimal false discovery rate control when the test statistics are dependent. An optimal joint oracle procedure, which minimizes the false non-discovery rate subject to a constraint on the false discovery rate is developed. A data-driven marginal plug-in procedure is then proposed to approximate the optimal joint procedure for multivariate normal data. It is shown that the marginal procedure is asymptotically optimal for multivariate normal data with a short-range dependent covariance structure. Numerical results show that the marginal procedure controls false discovery rate and leads to a smaller false non-discovery rate than several commonly used p-value based false discovery rate controlling methods. The procedure is illustrated by an application to a genome-wide association study of neuroblastoma and it identifies a few more genetic variants that are potentially associated with neuroblastoma than several p-value-based false discovery rate controlling procedures.

Xie, Jichun; Cai, T. Tony; Maris, John; Li, Hongzhe

2013-01-01

243

[Possible mechanisms of false positive results of averaged ECG].  

PubMed

The objective of this retrospective study was to investigate the causes of high amplification (HA) ECG abnormalities detected in apparently healthy subjects. This study was based on 14 patients derived from a population of 167 admitted for assessment of malaise or supraventricular tachycardia and who had no apparent heart disease. The surface ECG showed fine QRS complexes (< 120 ms) with no left hemiblock on ECG. All of these subjects underwent a complete electrophysiological study and high amplification ECG using a 40 Hertz high-pass filter. For these 14 patients, the amplitude of the last 40 milliseconds (ms) of the mean QRS (RMS 40) was less than or equal to 20 microvolts (microV). Eight of them also had a duration of the terminal part of the QRS complex less than 40 microV (LAS) greater than 40 ms and 6 others had and LAS greater than 35 ms. The mean QRS interval was normal in all patients (< 120 ms). The usual causes for reduction of the RMS 40-were eliminated: programmed ventricular pacing using 3 extrastimuli under basal conditions and with isuprel remained negative. E chocardiography and the right ventricular angiography were normal. The surface ECG showed slight abnormalities: absence of Q wave in V6 without delay of the intrinsic-like deflection in 3 subjects, increased R wave in V1 in 2 subjects and especially deep S wave in V5-V6 with no left axis deviation in 10 patients. Programmed or increasing frequency atrial pacing induced RBB or LBB in 13 of these 14 subjects (RBB: 7, LBB : 3, RBB and LBB:3). Follow-up, ranging from 6 months to 3 years, did not reveal any cardiac events, but signs of RBB appeared in 3 patients and signs of LBB were observed in 1 patient. In conclusion: an abnormal high amplification ECG in apparently healthy subjects could be explained by minor conduction disorders essentially in the right branch. The presence of a deep S wave (> 2 mm) in V5-V6 is the commonest ECG sign in these subjects. This diagnosis can only be proposed after exclusion of right ventricular dysplasia in symptomatic patients. PMID:9137672

Brembilla-Perrot, B; Beurrier, D; Jacquemin, L; Terrier de la Chaise, A; Danchin, N

1997-02-01

244

Panorama from 'Cape Verde' (False Color)  

NASA Technical Reports Server (NTRS)

NASA's Mars Exploration Rover Opportunity captured this vista of 'Victoria Crater' from the viewpoint of 'Cape Verde,' one of the promontories that are part of the scalloped rim of the crater. Opportunity drove onto Cape Verde shortly after arriving at the rim of Victoria in September 2006. The view combines hundreds of exposures taken by the rover's panoramic camera (Pancam). The camera began taking the component images during Opportunity's 970th Martian day, or sol, on Mars (Oct. 16, 2006). Work on the panorama continued through the solar conjunction period, when Mars was nearly behind the sun from Earth's perspective and communications were minimized. Acquisition of images for this panorama was completed on Opportunity's 991st sol (Nov. 7, 2006).

The top of Cape Verde is in the immediate foreground at the center of the image. To the left and right are two of the more gradually sloped bays that alternate with the cliff-faced capes or promontories around the rim of the crater. 'Duck Bay,' where Opportunity first reached the rim, is to the right. Beyond Duck Bay counterclockwise around the rim, the next promontory is 'Cabo Frio,' about 150 meters (500 feet) from the rover. On the left side of the panorama is 'Cape St. Mary,' the next promontory clockwise from Cape Verde and about 40 meters (130 feet) from the rover. The vantage point atop Cape Verde offered a good view of the rock layers in the cliff face of Cape St. Mary, which is about 15 meters or 50 feet tall. By about two weeks after the Pancam finished collecting the images for this panorama, Opportunity had driven to Cape St. Mary and was photographing Cape Verde's rock layers.

The far side of the crater lies about 800 meters (half a mile) away, toward the southeast.

This view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet). It is presented in false color to emphasize differences among materials in the rocks and soils.

2007-01-01

245

'Lyell' Panorama inside Victoria Crater (False Color)  

NASA Technical Reports Server (NTRS)

During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce this view, which is presented in a false-color stretch to bring out subtle color differences in the scene. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

Opportunity landed on Jan. 25, 2004, Universal Time, (Jan. 24, Pacific Time) inside a much smaller crater about 6 kilometers (4 miles) north of Victoria Crater, to begin a surface mission designed to last 3 months and drive about 600 meters (0.4 mile).

2008-01-01

246

Spirit's West Valley Panorama (False Color)  

NASA Technical Reports Server (NTRS)

NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle color differences in the scene.

2008-01-01

247

Do Optimal Prognostic Thresholds in Continuous Physiological Variables Really Exist? Analysis of Origin of Apparent Thresholds, with Systematic Review for Peak Oxygen Consumption, Ejection Fraction and BNP  

PubMed Central

Background Clinicians are sometimes advised to make decisions using thresholds in measured variables, derived from prognostic studies. Objectives We studied why there are conflicting apparently-optimal prognostic thresholds, for example in exercise peak oxygen uptake (pVO2), ejection fraction (EF), and Brain Natriuretic Peptide (BNP) in heart failure (HF). Data Sources and Eligibility Criteria Studies testing pVO2, EF or BNP prognostic thresholds in heart failure, published between 1990 and 2010, listed on Pubmed. Methods First, we examined studies testing pVO2, EF or BNP prognostic thresholds. Second, we created repeated simulations of 1500 patients to identify whether an apparently-optimal prognostic threshold indicates step change in risk. Results 33 studies (8946 patients) tested a pVO2 threshold. 18 found it prognostically significant: the actual reported threshold ranged widely (10–18 ml/kg/min) but was overwhelmingly controlled by the individual study population's mean pVO2 (r?=?0.86, p<0.00001). In contrast, the 15 negative publications were testing thresholds 199% further from their means (p?=?0.0001). Likewise, of 35 EF studies (10220 patients), the thresholds in the 22 positive reports were strongly determined by study means (r?=?0.90, p<0.0001). Similarly, in the 19 positives of 20 BNP studies (9725 patients): r?=?0.86 (p<0.0001). Second, survival simulations always discovered a “most significant” threshold, even when there was definitely no step change in mortality. With linear increase in risk, the apparently-optimal threshold was always near the sample mean (r?=?0.99, p<0.001). Limitations This study cannot report the best threshold for any of these variables; instead it explains how common clinical research procedures routinely produce false thresholds. Key Findings First, shifting (and/or disappearance) of an apparently-optimal prognostic threshold is strongly determined by studies' average pVO2, EF or BNP. Second, apparently-optimal thresholds always appear, even with no step in prognosis. Conclusions Emphatic therapeutic guidance based on thresholds from observational studies may be ill-founded. We should not assume that optimal thresholds, or any thresholds, exist.

Leong, Tora; Rehman, Michaela B.; Pastormerlo, Luigi Emilio; Harrell, Frank E.; Coats, Andrew J. S.; Francis, Darrel P.

2014-01-01

248

Curved apparent motion induced by amodal completion.  

PubMed

We investigated whether amodal completion can bias apparent motion (AM) to deviate from its default straight path toward a longer curved path, which would violate the well-established principle that AM follows the shortest possible path. Observers viewed motion sequences of two alternating rectangular tokens positioned at the ends of a semicircular occluder, with varying interstimulus intervals (ISIs; 100-500 ms). At short ISIs, observers tended to report simple straight-path motion-that is, outside the occluder. But at long ISIs, they became increasingly likely to report a curved-path motion behind the occluder. This tendency toward reporting curved-path motion was influenced by the shape of tokens, display orientation, the gap between tokens and the occluder, and binocular depth cues. Our results suggest that the visual system tends to minimize unexplained absence of a moving object, as well as its path length, such that AM deviates from the shortest path when amodal integration of motion trajectory behind the curved occluder can account for the objective invisibility of the object during the ISI. PMID:22069082

Kim, Sung-Ho; Feldman, Jacob; Singh, Manish

2012-02-01

249

Apparent speed increases at low luminance.  

PubMed

To investigate the effect of luminance on apparent speed, subjects adjusted the speed of a low-luminance rotating grating (0.31 cd/m(2)) to match that of a high-luminance one (1260 cd/m(2)). Above 4 Hz, subjects overestimated the speed of the low-luminance grating. This overestimation increased as a function of temporal rate and reached 30% around 10 Hz temporal rates. The speed overestimation became significant once the lower luminance was 2.4 log units lower than the high luminance comparison. Next the role of motion smear in speed overestimation was examined. First it was shown that the length of the perceived motion smear increased at low luminances. Second, the length of the visible smear was manipulated by changing the presentation time of the stimuli. Speed overestimation was reduced at shorter presentation times. Third the speed of a blurred stimulus was compared to a stimulus with sharp edges and the blurred stimulus was judged to move faster. These results indicate that the length of motion smear following a target contributes to its perceived speed and that this leads to speed overestimation at low luminance where motion traces lengthen because of increased persistence. PMID:19146275

Vaziri-Pashkam, Maryam; Cavanagh, Patrick

2008-01-01

250

Apparent Benzene Solubility in Tetraphenylborate Slurries  

SciTech Connect

Personnel conducted testing to determine the apparent solubility of benzene in potassium tetraphenylborate (KTPB) slurries. The lack of benzene vapor pressure suppression in these tests indicate that for a 6.5 wt percent solids KTPB slurry in 4.65 M Na+ salt solution at approximately 25 degrees Celsius, no significant difference exists between the solubility of benzene in the slurry and the solubility of benzene in salt solution without KTPB solids. The work showed similar results in slurry with 6,000 mg/L sludge and 2,000 mg/L monosodium titanate added. Slurries containing tetraphenylborate decomposition intermediates (i.e., 4,200 mg/L triphenylboron (3PB), 510 mg/L diphenylborinic acid (2PB) and 1,500 mg/L phenylboric acid (1PB) or 100 mg/L tri-n-butylphosphate (TBP)) also showed no significant difference in benzene solubility form filtrate containing no KTPB solids. Slurry containing 2,000 mg/L Surfynol 420 did exhibit significant additional benzene solubility, as did irradiated slurries. The vapor pressure depression in the irradiated slurries presumably results from dissolution of biphenyl and other tetraphenylborate irradiation products in the benzene.

Swingle, R.F.; Peterson, R.A.; Crawford, C.L.

1997-11-01

251

Gusev Rocks Solidified from Lava (False Color)  

NASA Technical Reports Server (NTRS)

In recent weeks, as NASA's Mars Exploration Rover Spirit has driven through the basin south of 'Husband Hill,' it has been traversing mainly sand and dune deposits. This week, though, Spirit has been maneuvering along the edge of an arc-shaped feature called 'Lorre Ridge' and has encountered some spectacular examples of basaltic rocks with striking textures. This panoramic camera (Pancam) image shows a group of boulders informally named 'FuYi.' These basaltic rocks were formed by volcanic processes and may be a primary constituent of Lorre Ridge and other interesting landforms in the basin.

Spirit first encountered basalts at its landing site two years ago, on a vast plain covered with solidified lava that appeared to have flowed across Gusev Crater. Later, basaltic rocks became rare as Spirit climbed Husband Hill. The basaltic rocks that Spirit is now seeing are interesting because they exhibit many small holes or vesicles, similar to some kinds of volcanic rocks on Earth. Vesicular rocks form when gas bubbles are trapped in lava flows and the rock solidifies around the bubbles. When the gas escapes, it leaves holes in the rock. The quantity of gas bubbles in rocks on Husband Hill varies considerably; some rocks have none and some, such as several here at FuYi, are downright frothy.

The change in textures and the location of the basalts may be signs that Spirit is driving along the edge of a lava flow. This lava may be the same as the basalt blanketing the plains of Spirit's landing site, or it may be different. The large size and frothy nature of the boulders around Lorre Ridge might indicate that eruptions once took place at the edge of the lava flow, where the lava interacted with the rocks of the basin floor. Scientists hope to learn more as Spirit continues to investigate these rocks.

As Earth approaches the Chinese New Year (The Year of the Dog), the Athena science team decided to use nicknames representing Chinese culture and geography to identify rocks and features investigated by Spirit during the Chinese New Year celebration period. In ancient Chinese myth, FuYi was the first great emperor and lived in the east. He explained the theory of 'Yin' and 'Yang' to his people, invented the net to catch fish, was the first to use fire to cook food, and invented a musical instrument known as the 'Se' to accompany his peoples' songs and dances. Other rocks and features are being informally named for Chinese gods, warriors, inventors, and scientists, as well as rivers, lakes, and mountains.

Spirit took this image on the rover's Martian day, or sol, 731 (Jan. 23, 2006). This is a false-color composite combining images taken with the Pancam's 750-nanometer, 530-nanometer and 430-nanometer filters.

2006-01-01

252

False-positive Ascaris suum egg counts in pigs  

Microsoft Academic Search

False-positive Ascaris suum egg counts in pig faeces are frequently observed under both experimental and natural conditions. Data from 12 experiments with A. suum infections in pigs were summarized and showed that the percentage of false-positive faecal samples ranged from 4 to 36%. False-positive egg count values varied greatly between pigs and experiments (range 20–1060 eggs per gram faeces). Indoor

Jaap Boes; Peter Nansen; Lani S. Stephenson

1997-01-01

253

Making sense of early false-belief understanding.  

PubMed

We address the puzzle about early belief ascription: young children fail elicited-response false-belief tasks, but they demonstrate spontaneous false-belief understanding. Based on recent converging evidence, we articulate a pragmatic framework to solve this puzzle. Young children do understand the contents of others' false belief, but they are overwhelmed when they must simultaneously make sense of two distinct actions: the instrumental action of a mistaken agent and the experimenter's communicative action. PMID:24612994

Helming, Katharina A; Strickland, Brent; Jacob, Pierre

2014-04-01

254

Apparent mineralocorticoid excess syndrome: an overview.  

PubMed

Apparent mineralocorticoid excess (AME) syndrome results from defective 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). This enzyme is co-expressed with the mineralocorticoid receptor (MR) in the kidney and converts cortisol (F) to its inactive metabolite cortisone (E). Its deficiency allows the unmetabolized cortisol to bind to the MR inducing sodium retention, hypokalemia, suppression of PRA and hypertension. Mutations in the gene encoding 11beta-HSD2 account for the inherited form, but a similar clinical picture to AME occurs following the ingestion of bioflavonoids, licorice and carbenoxolone, which are competitive inhibitors of 11beta-HSD2. Reduced 11beta-HSD2 activity may explain the increased sodium retention in preeclampsia, renal disease and liver cirrhosis. Relative deficiency of 11beta-HSD2 activity can occur in Cushing's syndrome due to saturation of the enzyme and explains the mineralocorticoid excess state that characterizes ectopic ACTH syndrome. Reduced placental 11beta-HSD2 expression might explain the link between reduced birth weight and adult hypertension. Polymorphic variability in the HSD11B2 gene in part determines salt sensitivity, a forerunner for adult hypertension onset. AME represents a spectrum of mineralocorticoid hypertension with severity reflecting the underlying genetic defect in the 11beta-HSD2; although AME is a genetic disorder, several exogenous compounds can bring about the symptoms by inhibiting 11beta-HSD2 enzyme. Substrate excess as seen in Cushing's syndrome and ACTH ectopic production can overwhelm the capacity of 11beta-HSD2 to convert F to E, leading up to an acquired form of AME. PMID:15761540

Palermo, Mario; Quinkler, Marcus; Stewart, Paul M

2004-10-01

255

Detection of gram-negative bacteria in urine by the chromogenic limulus assay  

Microsoft Academic Search

The value of the chromogenic limulus assay for detection of gram-negative bacteria in urine was determined. The assay was performed in microtiter plates at room temperature. In 311 consecutively collected urine samples from patients with suspected urinary tract infection, the assay was positive in all 35 samples containing ? 105 bacteria\\/ml. No false positive or false negative results were obtained.

M. Nurminen; M. Karvonen; A. Siitonen

1988-01-01

256

VarBin, a novel method for classifying true and false positive variants in NGS data  

PubMed Central

Background Variant discovery for rare genetic diseases using Illumina genome or exome sequencing involves screening of up to millions of variants to find only the one or few causative variant(s). Sequencing or alignment errors create "false positive" variants, which are often retained in the variant screening process. Methods to remove false positive variants often retain many false positive variants. This report presents VarBin, a method to prioritize variants based on a false positive variant likelihood prediction. Methods VarBin uses the Genome Analysis Toolkit variant calling software to calculate the variant-to-wild type genotype likelihood ratio at each variant change and position divided by read depth. The resulting Phred-scaled, likelihood-ratio by depth (PLRD) was used to segregate variants into 4 Bins with Bin 1 variants most likely true and Bin 4 most likely false positive. PLRD values were calculated for a proband of interest and 41 additional Illumina HiSeq, exome and whole genome samples (proband's family or unrelated samples). At variant sites without apparent sequencing or alignment error, wild type/non-variant calls cluster near -3 PLRD and variant calls typically cluster above 10 PLRD. Sites with systematic variant calling problems (evident by variant quality scores and biases as well as displayed on the iGV viewer) tend to have higher and more variable wild type/non-variant PLRD values. Depending on the separation of a proband's variant PLRD value from the cluster of wild type/non-variant PLRD values for background samples at the same variant change and position, the VarBin method's classification is assigned to each proband variant (Bin 1 to Bin 4). Results To assess VarBin performance, Sanger sequencing was performed on 98 variants in the proband and background samples. True variants were confirmed in 97% of Bin 1 variants, 30% of Bin 2, and 0% of Bin 3/Bin 4. Conclusions These data indicate that VarBin correctly classifies the majority of true variants as Bin 1 and Bin 3/4 contained only false positive variants. The "uncertain" Bin 2 contained both true and false positive variants. Future work will further differentiate the variants in Bin 2.

2013-01-01

257

Roles apparent resistivity amplitude and phase play in an aquifer's electrical-hydraulic conductivity correlation  

NASA Astrophysics Data System (ADS)

This paper argues how the spectral characteristics of two borehole apparent resistivity traces further corroborate two statistically significant electrical-hydraulic (eh) conductivity correlations previously reported in Nevada's fractured welded tuffs. Even though the eh conductivity correlation is positive in one borehole and negative in the other, as explained by low pore water electrical conductivity and the absence or presence of alteration minerals, both apparent resistivity amplitude spectra are identically power-law structured. This is interpreted to mean that eh flow is occurring along rock fractures of a common regional fractal dimension. Furthermore, both apparent resistivity phase spectra are strikingly linear, as mandated by the condition of incompressible fluids. Linear phase implies a groundwater flow that is geostatistically nonstationary in the wide sense, a complication normally not considered by hydrogeologists.

Purvance, David T.

2003-02-01

258

Estimating the Reliability of Multiple True-False Tests.  

ERIC Educational Resources Information Center

This study was designed to examine the level of dependence within multiple true-false test-item clusters by computing sets of item correlations with data from a test composed of both multiple true-false and multiple-choice items. (Author/LMO)

Frisbie, David A.; Druva, Cynthia A.

1986-01-01

259

Collection and evaluation of false alarm signatures in background data  

Microsoft Academic Search

A significant amount of background airborne data was collected as part of May 2005 tests for airborne minefield detection at an arid site. The locations of false alarms which occurred consistently during different runs, were identified and geo-referenced by MultiSensor Science LLC. Ground truth information, which included pictures, type qualifiers and some hyperspectral data for these identified false alarm locations,

Sanjeev Agarwal; Shivakar Vulli; Neil J. Malloy; Elizabeth M. Lord; Josh R. Fairley; Bruce M. Sabol; Wesley Johnson; Richard Ess; Anh H. Trang

2009-01-01

260

Effects of Aging and Education on False Memory  

ERIC Educational Resources Information Center

This study examined the effects of aging and education on participants' false memory for words that were not presented. Three age groups of participants with either a high or low education level were asked to study lists of semantically related words. Both age and education were found to affect veridical and false memory, as indicated in the…

Lee, Yuh-Shiow; Lee, Chia-Lin; Yang, Hua-Te

2012-01-01

261

False Memories for Suggestions: The Impact of Conceptual Elaboration  

ERIC Educational Resources Information Center

Relatively little attention has been paid to the potential role that reflecting on the meaning and implications of suggested events (i.e., conceptual elaboration) might play in promoting the creation of false memories. Two experiments assessed whether encouraging repeated conceptual elaboration, would, like perceptual elaboration, increase false

Zaragoza, Maria S.; Mitchell, Karen J.; Payment, Kristie; Drivdahl, Sarah

2011-01-01

262

False alarm effects on estimation in multitarget trackers  

Microsoft Academic Search

An analysis of false alarm effects on tracking filter performance in multitarget track-while-scan radars, using variable correlation gates, is presented. The false alarms considered originate from noise, clutter, and crossing targets. The dimensions of the correlation gates are determined by filter prediction and measurement error variances. Track association is implanted either by means of a distance weighted average of the

Arie Berman; Amnon Hammer

1991-01-01

263

Using Recall to Reduce False Recognition: Diagnostic and Disqualifying Monitoring  

ERIC Educational Resources Information Center

Whether recall of studied words (e.g., parsley, rosemary, thyme) could reduce false recognition of related lures (e.g., basil) was investigated. Subjects studied words from several categories for a final recognition memory test. Half of the subjects were given standard test instructions, and half were instructed to use recall to reduce false

Gallo, David A.

2004-01-01

264

A note on the adaptive control of false discovery rates  

Microsoft Academic Search

The use of a fixed rejection region for multiple hypothesis testing has been shown to outperform standard fixed error rate approaches when applied to control of the false discovery rate. In this work it is demonstrated that, if the original step-up procedure of Benjamini and Hochberg is modified to exercise adaptive control of the false discovery rate, its performance is

M. A. Black

2004-01-01

265

Creating false memories: Remembering words not presented in lists  

Microsoft Academic Search

Two experiments (modeled after J. Deese's 1959 study) revealed remarkable levels of false recall and false recognition in a list learning paradigm. In Experiment 1, subjects studied lists of 12 words (e.g., bed, rest, awake); each list was composed of associates of 1 nonpresented word (e.g., sleep). On immediate free recall tests, the nonpresented associates were recalled 40% of the

Henry L. Roediger; Kathleen B. McDermott

1995-01-01

266

False Belief, Complementation Language, and Contextual Bias in Preschoolers  

ERIC Educational Resources Information Center

In the present study, we address two questions concerning the relation between children's false belief and their understanding of complex object complements. The first question is whether the previously demonstrated association between tensed complements and false belief generalizes to infinitival complements (de Villiers & Pyers, 2002). The…

Ng, Lisa; Cheung, Him; Xiao, Wen

2010-01-01

267

Development of False Memories in Bilingual Children and Adults  

ERIC Educational Resources Information Center

The effects of within- versus between-languages (English-French) study and test on rates of bilingual children's and adults' true and false memories were examined. Children aged 6 through 12 and university-aged adults participated in a standard Deese-Roediger-McDermott false memory task using free recall and recognition. Recall results showed…

Howe, Mark L.; Gagnon, Nadine; Thouas, Lisa

2008-01-01

268

Associations among False Belief Understanding, Counterfactual Reasoning, and Executive Function  

ERIC Educational Resources Information Center

The primary purposes of the present study were to clarify previous work on the association between counterfactual thinking and false belief performance to determine (1) whether these two variables are related and (2) if so, whether executive function skills mediate the relationship. A total of 92 3-, 4-, and 5-year-olds completed false belief,…

Guajardo, Nicole R.; Parker, Jessica; Turley-Ames, Kandi

2009-01-01

269

Do Children "DRM" Like Adults? False Memory Production in Children  

ERIC Educational Resources Information Center

The Deese/Roediger-McDermott (DRM) paradigm was used to investigate developmental trends in accurate and false memory production. In Experiment 1, DRM lists adjusted to be more consistent with children's vocabulary were used with 2nd graders, 8th graders, and college students. Accurate and false recall and recognition increased with age, but…

Metzger, Richard L.; Warren, Amye R.; Shelton, Jill T.; Price, Jodi; Reed, Andrea W.; Williams, Danny

2008-01-01

270

A digital ASIC for synthesizing false target radar images  

Microsoft Academic Search

Modern, wideband, inverse synthetic aperture radar (ISAR) is capable of generating images of targets, rendering traditional false target decoy methods obsolete. The paper describes an application specific integrated circuit (ASIC) capable of generating false target decoy images for countering imaging ISARs. The application and operation of the ASIC in an electronic attack system is also discussed. The fully programmable chip

Douglas J. Fouts; P. E. Pace; C. Karow; S. R. T. Ekestorm

2002-01-01

271

False Belief and Language Comprehension in Cantonese-Speaking Children  

ERIC Educational Resources Information Center

The current research compared two accounts of the relation between language and false belief in children, namely that (a) language is generally related to false belief because both require secondary representation in a social-interactional context and that (b) specific language structures that explicitly code meta representation contribute…

Cheung, Him

2006-01-01

272

Gain-Scheduled Fault Tolerance Control Under False Identification  

NASA Technical Reports Server (NTRS)

An active fault tolerant control (FTC) law is generally sensitive to false identification since the control gain is reconfigured for fault occurrence. In the conventional FTC law design procedure, dynamic variations due to false identification are not considered. In this paper, an FTC synthesis method is developed in order to consider possible variations of closed-loop dynamics under false identification into the control design procedure. An active FTC synthesis problem is formulated into an LMI optimization problem to minimize the upper bound of the induced-L2 norm which can represent the worst-case performance degradation due to false identification. The developed synthesis method is applied for control of the longitudinal motions of FASER (Free-flying Airplane for Subscale Experimental Research). The designed FTC law of the airplane is simulated for pitch angle command tracking under a false identification case.

Shin, Jong-Yeob; Belcastro, Christine (Technical Monitor)

2006-01-01

273

Diagnostic Accuracy of Apparent Diffusion Coefficient and 123I-Metaiodobenzylguanidine for Differentiation of Multiple System Atrophy and Parkinson's Disease  

PubMed Central

Background It is often hard to differentiate Parkinson’s disease (PD) and parkinsonian variant of multiple system atrophy (MSA-P), especially in the early stages. Cardiac sympathetic denervation and putaminal rarefaction are specific findings for PD and MSA-P, respectively. Purpose We investigated diagnostic accuracy of putaminal apparent diffusion coefficient (ADC) test for MSA-P and 123I-metaiodobenzylguanidine (MIBG) scintigram for PD, especially in early-stage patients. Methods The referral standard diagnosis of PD and MSA-P were the diagnostic criteria of the United Kingdom Parkinson’s Disease Society Brain Bank Criteria and the second consensus criteria, respectively. Based on the referral standard criteria, diagnostic accuracy [area under the receiver-operator characteristic curve (AUC), sensitivity and specificity] of the ADC and MIBG tests was estimated retrospectively. Diagnostic accuracy of these tests performed within 3 years of symptom onset was also investigated. Results ADC and MIBG tests were performed on 138 patients (20 MSA and 118 PD). AUC was 0.95 and 0.83 for the ADC and MIBG tests, respectively. Sensitivity and specificity were 85.0% and 89.0% for MSA-P diagnosis by ADC test and 67.0% and 80.0% for PD diagnosis by MIBG test. When these tests were restricted to patients with disease duration ?3 years, the sensitivity and specificity were 75.0% and 91.4% for the ADC test (MSA-P diagnosis) and 47.7% and 92.3% for the MIBG test (PD diagnosis). Conclusions Both tests were useful in differentiating between PD and MSA-P, even in the early stages. In early-stage patients, elevated putaminal ADC was a diagnostic marker for MSA-P. Despite high specificity of the MIBG test, careful neurological history and examinations were required for PD diagnosis because of possible false-negative results.

Umemura, Atsushi; Oeda, Tomoko; Hayashi, Ryutaro; Tomita, Satoshi; Kohsaka, Masayuki; Yamamoto, Kenji; Sawada, Hideyuki

2013-01-01

274

Right and Righteous: Children's Incipient Understanding and Evaluation of True and False Statements  

PubMed Central

Two studies examined young children’s early understanding and evaluation of truth-telling and lying, and the role that factuality plays in their judgments. Study 1 (104 2- to 5-year-olds) found that even the youngest children reliably accepted true statements and rejected false statements, and that older children’s ability to label true and false statements as “truth” and “lie” emerged in tandem with their positive evaluation of true statements and “truth” and their negative evaluation of false statements and “lie.” The findings suggest that children’s early preference for factuality develops into a conception of “truth” and “lie” that is linked both to factuality and moral evaluation. Study 2 (128 3- to 5-year-olds) found that, whereas young children exhibited good understanding of the association of true and false statements with “truth,” “lie,” “mistake,” “right,” and “wrong,” they showed little awareness of assumptions about speaker knowledge underlying “lie” and “mistake.” The results further support the primacy of factuality in children’s early understanding and evaluation of truth and lies.

Lyon, Thomas D.; Quas, Jodi A.; Carrick, Nathalie

2012-01-01

275

Semantic processes leading to true and false memory formation in schizophrenia  

PubMed Central

Encoding semantic relationships between items on word lists (semantic processing) enhances true memories, but also increases memory distortions. Episodic memory impairments in schizophrenia (SZ) are strongly driven by failures to process semantic relations, but the exact nature of these relational semantic processing deficits are not well understood. Here, we used a false memory paradigm to investigate the impact of implicit and explicit semantic processing manipulations on episodic memory in SZ. Thirty SZ and 30 demographically matched healthy controls (HC) studied Deese/Roediger-McDermott (DRM) lists of semantically associated words. Half of the lists had strong implicit semantic associations and the remainder had low strength associations. Similarly, half of the lists were presented under “standard” instructions and the other half under explicit “relational processing” instructions. After study, participants performed recall and old/new recognition tests composed of targets, critical lures, and unrelated lures. HC exhibited higher true memories and better discriminability between true and false memory compared to SZ. High, versus low, associative strength increased false memory rates in both groups. However, explicit “relational processing” instructions positively improved true memory rates only in HC. Finally, true and false memory rates were associated with severity of disorganized and negative symptoms in SZ. These results suggest that reduced processing of semantic relationships during encoding in SZ may stem from an inability to implement explicit relational processing strategies rather than a fundamental deficit in the implicit activation and retrieval of word meanings from patients’ semantic lexicon.

Paz-Alonso, Pedro M.; Ghetti, Simona; Ramsay, Ian; Solomon, Marjorie; Yoon, Jong; Carter, Cameron S.; Ragland, J. Daniel

2013-01-01

276

Phencyclidine false positive induced by lamotrigine (Lamictal(R)) on a rapid urine toxicology screen  

PubMed Central

Background This report describes two cases with unexplained positive results for phencyclidine (PCP). Aims This case will correlate lamotrigine (Lamictal®) use with false-positive results for PCP on a rapid urine toxicology screen. Methods Case 1: A 62-year-old male arrived to the emergency department in extreme psychosis. All positive results on the urine drug screen could be accounted for except PCP. A comprehensive drug screen was performed to confirm PCP use, but returned negative. PCP was ruled out as the causative agent. The reason for the PCP false positive remained unknown. Case 2: A 49-year-old female presented to the ED with a history of seizures and depression. Despite positive PCP results on a rapid urine drug screen, PCP use was ruled out due to patient presentation and comprehensive history. Results The differential diagnosis in case 1 included PCP abuse until PCP was ruled out by a comprehensive drug screen. A literature search failed to explain a reason for false-positive results. The patient in case 2 was not psychotic, but returned a positive urinalysis result for PCP. Case 2’s presentation combined with a comprehensive history at the facility ruled out PCP use. Both patients were taking the anti-seizure medication lamotrigine with nothing else in common. Conclusion Lamotrigine has the potential to cause false-positive results for PCP on the Bio-Rad TOX/See urine toxicology screen.

Peele, James; McCoy, Stacey L.; Elias, Brad

2010-01-01

277

False positives complicate ancient pathogen identifications using high-throughput shotgun sequencing  

PubMed Central

Background Identification of historic pathogens is challenging since false positives and negatives are a serious risk. Environmental non-pathogenic contaminants are ubiquitous. Furthermore, public genetic databases contain limited information regarding these species. High-throughput sequencing may help reliably detect and identify historic pathogens. Results We shotgun-sequenced 8 16th-century Mixtec individuals from the site of Teposcolula Yucundaa (Oaxaca, Mexico) who are reported to have died from the huey cocoliztli (‘Great Pestilence’ in Nahautl), an unknown disease that decimated native Mexican populations during the Spanish colonial period, in order to identify the pathogen. Comparison of these sequences with those deriving from the surrounding soil and from 4 precontact individuals from the site found a wide variety of contaminant organisms that confounded analyses. Without the comparative sequence data from the precontact individuals and soil, false positives for Yersinia pestis and rickettsiosis could have been reported. Conclusions False positives and negatives remain problematic in ancient DNA analyses despite the application of high-throughput sequencing. Our results suggest that several studies claiming the discovery of ancient pathogens may need further verification. Additionally, true single molecule sequencing’s short read lengths, inability to sequence through DNA lesions, and limited ancient-DNA-specific technical development hinder its application to palaeopathology.

2014-01-01

278

Confounding Underlies the Apparent Month of Birth Effect in Multiple Sclerosis  

PubMed Central

Objective Several groups have reported apparent association between month of birth and multiple sclerosis. We sought to test the extent to which such studies might be confounded by extraneous variables such as year and place of birth. Methods Using national birth statistics from 2 continents, we assessed the evidence for seasonal variations in birth rate and tested the extent to which these are subject to regional and temporal variation. We then established the age and regional origin distribution for a typical multiple sclerosis case collection and determined the false-positive rate expected when comparing such a collection with birth rates estimated by averaging population-specific national statistics. Results We confirm that seasonality in birth rate is ubiquitous and subject to highly significant regional and temporal variations. In the context of this variation we show that birth rates observed in typical case collections are highly likely to deviate significantly from those obtained by the simple unweighted averaging of national statistics. The significant correlations between birth rates and both place (latitude) and time (year of birth) that characterize the general population indicate that the apparent seasonal patterns for month of birth suggested to be specific for multiple sclerosis (increased in the spring and reduced in the winter) are expected by chance alone. Interpretation In the absence of adequate control for confounding factors, such as year and place of birth, our analyses indicate that the previous claims for association of multiple sclerosis with month of birth are probably false positives. ANN NEUROL 2013;73:714–720

Fiddes, Barnaby; Wason, James; Kemppinen, Anu; Ban, Maria; Compston, Alastair; Sawcer, Stephen

2013-01-01

279

De novo and apparent de novo hepatitis B virus infection after liver transplantation  

Microsoft Academic Search

Background\\/Aims: The aim of this study was to clarify the aetiology of apparent de novo HBV infection after liver transplantation.Methods: Twenty out of 570 HBsAg negative patients (3.5%) became HBsAg positive after transplantation and were studied. Donor and recipient sera were retrospectively tested for HBsAg, anti-HBs, anti-HBc, and HBV DNA by PCR. Donor and recipient livers were tested for HBV

Bruno Roche; Didier Samuel; Michele Gigou; Cyrille Feray; Veronique Virot; Laurent Schmets; Marie Françoise David; Jean Louis Arulnaden; Alain Bismuth; Michel Reynes; Henri Bismuth

1997-01-01

280

Gas-phase processes and measurements of macromolecular properties in solution: On the possibility of false positive and false negative signals of protein unfolding  

Microsoft Academic Search

Electrospray ionization mass spectrometry is increasingly applied to study protein behavior in solution, including characterization of their higher order structure, conformational dynamics and interactions with small ligands and other biopolymers. However, actual measurements of fundamental ionic parameters (mass and charge) take place in vacuum, and an array of gas phase processes occurring prior to protein ion detection and characterization may

Rinat R. Abzalimov; Agya K. Frimpong; Igor A. Kaltashov

2006-01-01

281

Assessment of False Positive and False Negative Confirmation Rates for Fecal Coliforms by EPA Methods 1680 and 1681 in Sewage Sludge Matrices.  

National Technical Information Service (NTIS)

In 2004, EPA completed the report for the interlaboratory validation of EPA Methods 1680 (LTB/EC) and 1681 (A1) for fecal coliforms in sewage sludge (biosolids) (EPA 821-B-04-007). In 2005 (FR 70:48256) EPA proposed these methods for use in sewage sludge....

2008-01-01

282

Neural correlates underlying true and false associative memories.  

PubMed

Despite the fact that associative memory studies produce a large number of false memories, neuroimaging analyses utilizing this paradigm typically focus only on neural activity mediating successful retrieval. The current study sought to expand on this prior research by examining the neural basis of both true and false associative memories. Though associative false memories are substantially different than those found in semantic or perceptual false memory paradigms, results suggest that associative false memories are mediated by similar neural mechanisms. Specifically, we found increased frontal activity that likely represents enhanced monitoring and evaluation compared to that needed for true memories and correct rejections. Results also indicated that true, and not false associative memories, are mediated by neural activity in the MTL, specifically the hippocampus. Finally, while activity in early visual cortex distinguished true from false memories, a lack of neural differences between hits and correct rejections failed to support previous findings suggesting that activity in early visual cortex represents sensory reactivation of encoding-related processing. PMID:24859815

Dennis, Nancy A; Johnson, Christina E; Peterson, Kristina M

2014-07-01

283

Collection and evaluation of false alarm signatures in background data  

NASA Astrophysics Data System (ADS)

A significant amount of background airborne data was collected as part of May 2005 tests for airborne minefield detection at an arid site. The locations of false alarms which occurred consistently during different runs, were identified and geo-referenced by MultiSensor Science LLC. Ground truth information, which included pictures, type qualifiers and some hyperspectral data for these identified false alarm locations, was surveyed by ERDC-WES. This collection of background data, and subsequent survey of the false alarm locations, is unique in that it is likely the first such airborne data collection with ground truthed and documented false alarm locations. A library of signatures for different sources of these false alarms was extracted in the form of image chips and organized into a self-contained database by Missouri S&T. The library contains target chips from airborne mid wave infrared (MWIR) and multispectral imaging (MSI) sensors, representing data for different days, different times of day and different altitudes. Target chips for different surface mines were also added to the database. This database of the target signatures is expected to facilitate evaluation of spectral and shape characteristics of the false alarms, to achieve better false alarm mitigation and improve mine and minefield detection for airborne applications. The aim of this paper is to review and summarize the data collection procedure used, present the currently available database of target chips and make some recommendations regarding future data collections.

Agarwal, Sanjeev; Vulli, Shivakar; Malloy, Neil J.; Lord, Elizabeth M.; Fairley, Josh R.; Sabol, Bruce M.; Johnson, Wesley; Ess, Richard; Trang, Anh H.

2009-05-01

284

False recall and recognition of brand names increases over time.  

PubMed

Using the Deese-Roediger-McDermott (DRM) paradigm, participants are presented with lists of associated words (e.g., bed, awake, night). Subsequently, they reliably have false memories for related but nonpresented words (e.g., SLEEP). Previous research has found that false memories can be created for brand names (e.g., Morrisons, Sainsbury's, Waitrose, and TESCO). The present study investigates the effect of a week's delay on false memories for brand names. Participants were presented with lists of brand names followed by a distractor task. In two between-subjects experiments, participants completed a free recall task or a recognition task either immediately or a week later. In two within-subjects experiments, participants completed a free recall task or a recognition task both immediately and a week later. Correct recall for presented list items decreased over time, whereas false recall for nonpresented lure items increased. For recognition, raw scores revealed an increase in false memory across time reflected in an increase in Remember responses. Analysis of Pr scores revealed that false memory for lures stayed constant over a week, but with an increase in Remember responses in the between-subjects experiment and a trend in the same direction in the within-subjects experiment. Implications for theories of false memory are discussed. PMID:22963741

Sherman, Susan M

2013-01-01

285

Using story contexts to bias children's true and false memories.  

PubMed

The effects of embedding standard Deese/Roediger-McDermott (DRM) lists into stories whose context biased interpretation either toward or away from the overall themes of the DRM lists on both true and false recognition were investigated with 7- and 11-year-olds. These biased story contexts were compared with the same children's susceptibility to false memory illusions using the standard DRM list presentation paradigm. The results showed the usual age effects for true and false memories in the standard DRM list paradigm, where 11-year-olds exhibited higher rates of both true and false recognition compared with the 7-year-olds. Importantly, when DRM lists were embedded in stories, these age effects disappeared for true recognition. For false recognition, although developmental differences were attenuated, older children were still more susceptible to false memory illusions than younger children. These findings are discussed in terms of current theories of children's false memories as well as the role of themes and elaboration in children's memory development. PMID:20678778

Howe, Mark L; Wilkinson, Samantha

2011-01-01

286

Lexical association and false memory for words in two cultures.  

PubMed

This study examined the relationship between language experience and false memory produced by the DRM paradigm. The word lists used in Stadler, et al. (Memory & Cognition, 27, 494-500, 1999) were first translated into Chinese. False recall and false recognition for critical non-presented targets were then tested on a group of Chinese users. The average co-occurrence rate of the list word and the critical word was calculated based on two large Chinese corpuses. List-level analyses revealed that the correlation between the American and Taiwanese participants was significant only in false recognition. More importantly, the co-occurrence rate was significantly correlated with false recall and recognition of Taiwanese participants, and not of American participants. In addition, the backward association strength based on Nelson et al. (The University of South Florida word association, rhyme and word fragment norms, 1999) was significantly correlated with false recall of American participants and not of Taiwanese participants. Results are discussed in terms of the relationship between language experiences and lexical association in creating false memory for word lists. PMID:17624610

Lee, Yuh-shiow; Chiang, Wen-Chi; Hung, Hsu-Ching

2008-01-01

287

False recognition of emotional stimuli is lateralised in the brain: An fMRI study.  

PubMed

We have investigated whether the left (LH) and right (RH) hemisphere play a different role in eliciting false recognition (FR) and whether their involvement in this memory illusion depends on the emotional content of stimuli. Negative and neutral pictures (taken from IAPS) were presented in the divided-visual field paradigm. Subjects task was to indicate whether the pictures had already been presented or not during the preceding study phase. FR rate was much higher for the RH than the LH presentations. In line, FR resulted in activations mainly in the right prefrontal cortex (PFC) for either RH or LH presentations. Emotional content of stimuli facilitated the formation of false memories and strengthened the involvement of the right PFC in FR induction. PMID:18329298

Marchewka, A; Brechmann, A; Nowicka, A; Jednoróg, K; Scheich, H; Grabowska, A

2008-07-01

288

Meningitis - gram-negative  

MedlinePLUS

Gram-negative meningitis ... Acute bacterial meningitis can be caused by Gram-negative bacteria. Meningococcal and H. influenzae meningitis are due to Gram-negative bacteria and are covered in detail in other articles. This article ...

289

24 CFR 4001.401 - Notice of false information from mortgagor-procedure.  

Code of Federal Regulations, 2010 CFR

...Development 5 2009-04-01 2009-04-01 false Notice of false information from mortgagor-procedure. 4001.401...HOPE FOR HOMEOWNERS PROGRAM Enforcement Mortgagor False Information § 4001.401 Notice of false...

2009-04-01

290

24 CFR 4001.401 - Notice of false information from mortgagor-procedure.  

Code of Federal Regulations, 2010 CFR

...Development 5 2010-04-01 2010-04-01 false Notice of false information from mortgagor-procedure. 4001.401...HOPE FOR HOMEOWNERS PROGRAM Enforcement Mortgagor False Information § 4001.401 Notice of false...

2010-04-01

291

24 CFR 257.401 - Notice of false information from mortgagor-procedure.  

Code of Federal Regulations, 2010 CFR

...Development 2 2010-04-01 2010-04-01 false Notice of false information from mortgagor-procedure. 257.401...HOPE FOR HOMEOWNERS PROGRAM Enforcement Mortgagor False Information § 257.401 Notice of false...

2010-04-01

292

Apparent lethal concentrations of pyrolysis products of some polymeric materials  

NASA Technical Reports Server (NTRS)

Thirty-nine samples of polymeric materials were evaluated to determine the apparent lethal concentrations of their pyrolysis products. The materials were compared on the basis of the apparent lethal concentration for 50 percent of the test animals. Relative toxicity rankings based o apparent lethal concentration values can differ significantly depending on whether they are based on weight of sample charged or weight of sample pyrolyzed. The ranking of polyphenylene sulfide is particularly sensitive to this difference.

Hilado, C. J.; Marcussen, W. H.; Furst, A.; Kourtides, D. A.; Parker, J. A.

1976-01-01

293

Animals in Education: Are We Prisoners of False Sentiment?  

ERIC Educational Resources Information Center

Asserts that concerns over the use of animals in science education is confounded by the unworthy introduction of false sentiment by animal rights groups, which persist in ignoring the realities of biology. (PR)

Minerney, Joseph D.

1993-01-01

294

False alarm effects on estimation in multitarget trackers  

NASA Astrophysics Data System (ADS)

An analysis of false alarm effects on tracking filter performance in multitarget track-while-scan radars, using variable correlation gates, is presented. The false alarms considered originate from noise, clutter, and crossing targets. The dimensions of the correlation gates are determined by filter prediction and measurement error variances. Track association is implanted either by means of a distance weighted average of the observations or by the nearest neighbor rule. State estimation is performed by means of a second-order discrete Kalman filter, taking into consideration random target maneuvers. Measurements are made in polar coordinates, while target dynamics are estimated in Cartesian coordinates, resulting in coupled linear filter equations. The effect of false alarms on the observation noise covariance matrix, and hence on state estimation errors, is analyzed. A computer simulation example, implementing radar target tracking with a variable correlation gate in the presence of false alarms, is discussed.

Berman, Arie; Hammer, Amnon

1991-07-01

295

Expert System Constant False Alarm Rate (CFAR) Processor.  

National Technical Information Service (NTIS)

An artificial intelligence system improves radar signal processor performance by increasing target probability of detection and reducing probability of false alarm in a severe radar clutter environment. This utilizes advances in artificial intelligence an...

M. C. Wicks

2006-01-01

296

The strategic nature of false recognition in the DRM paradigm.  

PubMed

The false memory effect produced by the Deese/Roediger & McDermott (DRM) paradigm is reportedly impervious to warnings to avoid false alarming to the critical lures (D. A. Gallo, H. L. Roediger III, & K. B. McDermott, 2001). This finding has been used as strong evidence against models that attribute the false alarms to a decision process (e.g., M. B. Miller & G. L. Wolford, 1999). In this report, the authors clarify their earlier article and suggest that subjects establish only 2 underlying criteria for a recognition judgment, a liberal criterion for items that seem to be related to 1 of the study list themes and a conservative criterion for items that do not seem to be related. They demonstrate that warnings designed on the basis of these underlying criteria are effective in significantly suppressing the false recognition effect, suggesting that strategic control of the retrieval response does play a role in the DRM paradigm. PMID:21767060

Miller, Michael B; Guerin, Scott A; Wolford, George L

2011-09-01

297

False alarm mitigation techniques for hyperspectral target detection  

NASA Astrophysics Data System (ADS)

A challenging problem of major importance in hyperspectral imaging applications is the detection of subpixel objects of military and civilian interest. High false alarm thresholds are required to detect subpixel objects due to the large amount of surrounding background clutter. These high false alarm rates are unacceptable for military purposes, requiring the need for false alarm mitigation (FAM) techniques to weed out the objects of interest. The objective of this paper is to provide a comparison of the implementation of these FAM techniques and their inherent benefits in the whitened detection space. The widely utilized matched filter (MF) and adaptive cosine estimator (ACE) are both based on a linear mixing model (LMM) between a background and object class. The matched filter approximates the object abundance, and the ACE measures the model error. Each of these measurements provides inadequate object separation alone, but by using both the object abundance and model error, the objects can be separated from the false alarms.

Pieper, M. L.; Manolakis, D.; Truslow, E.; Cooley, T.; Brueggeman, M.

2013-05-01

298

False memories in highly superior autobiographical memory individuals  

PubMed Central

The recent identification of highly superior autobiographical memory (HSAM) raised the possibility that there may be individuals who are immune to memory distortions. We measured HSAM participants’ and age- and sex-matched controls’ susceptibility to false memories using several research paradigms. HSAM participants and controls were both susceptible to false recognition of nonpresented critical lure words in an associative word-list task. In a misinformation task, HSAM participants showed higher overall false memory compared with that of controls for details in a photographic slideshow. HSAM participants were equally as likely as controls to mistakenly report they had seen nonexistent footage of a plane crash. Finding false memories in a superior-memory group suggests that malleable reconstructive mechanisms may be fundamental to episodic remembering. Paradoxically, HSAM individuals may retrieve abundant and accurate autobiographical memories using fallible reconstructive processes.

Patihis, Lawrence; Frenda, Steven J.; LePort, Aurora K. R.; Petersen, Nicole; Nichols, Rebecca M.; Stark, Craig E. L.; McGaugh, James L.; Loftus, Elizabeth F.

2013-01-01

299

Retrieval Failure Contributes to Gist-Based False Recognition  

PubMed Central

People often falsely recognize items that are similar to previously encountered items. This robust memory error is referred to as gist-based false recognition. A widely held view is that this error occurs because the details fade rapidly from our memory. Contrary to this view, an initial experiment revealed that, following the same encoding conditions that produce high rates of gist-based false recognition, participants overwhelmingly chose the correct target rather than its related foil when given the option to do so. A second experiment showed that this result is due to increased access to stored details provided by reinstatement of the originally encoded photograph, rather than to increased attention to the details. Collectively, these results suggest that details needed for accurate recognition are, to a large extent, still stored in memory and that a critical factor determining whether false recognition will occur is whether these details can be accessed during retrieval.

Guerin, Scott A.; Robbins, Clifford A.; Gilmore, Adrian W.; Schacter, Daniel L.

2011-01-01

300

Evaluation of false transrectal ultrasonographic pregnancy diagnoses in sheep by measuring the plasma level of pregnancy-associated glycoproteins.  

PubMed

The present study was undertaken to investigate to what extent pregnancy diagnoses made by transrectal ultrasonography could be confirmed by measurements of plasma concentration of ovine pregnancy-associated glycoproteins (ovPAG). A total of 424 Awassi x Merino ewes were synchronized for estrus and examined by transrectal ultrasonography. In Experiment 1, the ewes (n = 156) were repeatedly scanned in a standing position on d 29, 36 and 50 of gestation. Similarly, the ewes (n = 268) in Experiment 2 were scanned on d 24, 29 and 34 of gestation, but these ewes were fasted for 12 h prior to the examination and the abdominal wall of each animal was lifted up by the hands of the assistant during the scanning. Blood samples were withdrawn after each transrectal ultrasonographic examination in both experiments. Ovine PAG concentrations were measured in plasma by a heterologous radioimmunoassay and the cut-off value for pregnancy was > or = 1 ng.mL-1. Based on the lambing performance, in Experiment 1, altogether 47 false negative and 38 false positive diagnoses were made by transrectal ultrasonography in 24 and 33 ewes, respectively between d 29 and 50 of gestation. In Experiment 2, altogether 8 false negative and 13 false positive diagnoses both were made in 7 ewes between d 24 and 34 of gestation. In both experiments, all ewes with false negative diagnoses had ovPAG concentrations higher than the threshold level for pregnancy diagnosis and all ewes with false positive diagnoses had ovPAG concentrations lower than the threshold of pregnancy. Furthermore, by the PAG-RIA test all lambed or aborted ewes (n = 63) were correctly diagnosed as pregnant and with three exceptions, all non-lambed ewes (n = 361) were correctly diagnosed as non-pregnant during the examined periods of both experiments. PMID:15141441

Karen, Aly; Beckers, Jean-François; Sulon, Jose; el Amiri, Bouchra; Szabados, Krisztián; Ismail, Sanaa; Reiczigel, Jenö; Szenci, Ottó

2003-01-01

301

Script knowledge enhances the development of children's false memories  

Microsoft Academic Search

We examined whether script knowledge contributes to the development of children's false memories. Sixty 7-year-old and 60 11-year-old children listened to false narratives describing either a high-knowl- edge event (i.e., fingers being caught in a mousetrap) or a low-knowledge event (i.e., receiving a rectal enema) that were similar in terms of plausibility and pleasantness. Moreover, half of the children in

Henry Otgaar; Ingrid Candel; Alan Scoboria; Harald Merckelbach

2009-01-01

302

Validity of False Belief Tasks in Blind Children  

Microsoft Academic Search

Previous studies have reported that congenitally blind children without any additional impairment reveal a developmental delay\\u000a of at least 4 years in perspective taking based on testing first-order false-belief tasks. These authors interpret this delay\\u000a as a sign of autism-like behavior. However, the delay may be caused by testing blind children with false-belief tasks that\\u000a require visual experience. Therefore, the present

Michael Brambring; Doreen Asbrock

2010-01-01

303

[Stenting of the right subclavian artery posttraumatic false aneurysm].  

PubMed

Posttraumatic false aneUrysms can be life threatening and often their management might be a challenge, because of poor general condition as well as because of specific technical difficulties. Open surgery requires wide exposure and dissection of posttraumatic tissues. Endovascular techniques using stent-grafts gains popularity because of high efficiency, safety and good results. We present a case of posttraumatic false aneurysm of right subclavian artery treated with a stent-graft. PMID:12122749

Petrov, I; Chevenkov, V; Grozdinski, L; Dzhorgova, Iu; Chirkov, A

2001-01-01

304

Analysis of Postsurgical Aortic False Aneurysm in 27 Patients  

PubMed Central

Aortic false aneurysm is a rare complication after cardiac surgery. In recent years, improved results have been reported in regard to the surgical management of these high-risk lesions. We retrospectively examined 28 consecutive cases (in 27 patients) of postsurgical aortic false aneurysm diagnosed at our institution from May 1999 through December 2011. Twenty-four patients underwent reoperation. Cardiopulmonary bypass was instituted before sternotomy in 15 patients (63%). Isolated repair of the aortic false aneurysm was performed in 15 patients. Four patients (including one who had already undergone repeat false-aneurysm repair) declined surgery in favor of clinical monitoring. Eleven patients were asymptomatic at the time of diagnosis. In the other 16, the main cause was infection in 7, and previous operation for acute aortic dissection in 9. The in-hospital mortality rate was 16.6% (4 patients, 3 of whom had infective false aneurysms). Relevant postoperative sequelae were noted in 7 patients (29%). The cumulative 1-year and 5-year survival rates were 83% and 62%, respectively. The 4 patients who did not undergo reoperation were alive at a median interval of 23 months (range, 9–37 mo). Two underwent imaging evaluations; in one, computed tomography revealed an 8-mm increase of the false aneurysm's maximal diameter at 34 months. Aortic false aneurysm can develop silently. Surgical procedures should be proposed even to asymptomatic patients because of the unpredictable evolution of the condition. Radical aortic-graft replacement should be chosen rather than simple repair, because recurrent false aneurysm is possible.

Malvindi, Pietro Giorgio; Cappai, Antioco; Raffa, Giuseppe Maria; Barbone, Alessandro; Basciu, Alessio; Citterio, Enrico; Ornaghi, Diego; Tarelli, Giuseppe; Settepani, Fabrizio

2013-01-01

305

False-positive cryptococcal antigen test and cervical prevertebral abscess.  

PubMed

A false-positive latex agglutination test for cryptococcal antigen occurred in a patient with a cervical prevertebral abscess and vertebral osteomyelitis caused by Klebsiella pneumoniae. Using a commercial latex agglutination test kit, a cryptococcal antigen titer of 1:32 was found in the CSF, but no cryptococcal antigen was found when the CSF was retested at a reference laboratory. The false-positive test resulted in unnecessary therapy with amphotericin B and delay in appropriate diagnostic studies and therapy. PMID:357768

MacKinnon, S; Kane, J G; Parker, R H

1978-10-27

306

The effects of social pressure on false memories  

Microsoft Academic Search

The present experiments were designed to examine the effects of social pressure on false memories. Participants studied lists\\u000a created to elicit false memories and then worked in conjunction with virtual confederates on a recognition memory task. In\\u000a Experiment 1, participants worked with one or two confederates to complete multiple study—test trials. On the group tests,\\u000a participants were implicitly pressured to

Matthew B. Reysen

2007-01-01

307

Grey-matter differences related to true and false recognition of emotionally charged stimuli - a voxel based morphometry study.  

PubMed

The issue concerning the neuronal basis of true and false recognition is still a subject of extensive debate. In the present study voxel based morphometry (VBM) was used to examine structural brain correlates of these processes. Since several studies indicate that emotional content facilitates false recognition we decided to use emotional stimuli. Behavioral measures, i.e., true and false recognition rates were used as covariants in VBM analyses. VBM results indicated that the true recognition correlated positively with grey-matter (GM) density in bilateral amygdala, anterior cingulate and middle temporal gyrus, i.e., brain regions, involved in the memory of emotional material, as revealed by fMRI results. False recognition correlated negatively with GM density in prefrontal areas (BA47 and BA9), supporting the role of the prefrontal cortex in monitoring retrieval and limiting the probability of false recognition. Thus our VBM findings (i) point to the brain structures critical for correct and false emotional memory and (ii) disclose structural differences between the neural bases of these two types of memory. PMID:19292997

Marchewka, Artur; Jednoróg, Katarzyna; Nowicka, Anna; Brechmann, André; Grabowska, Anna

2009-07-01

308

False-positive Xpert(®) MTB/RIF assays in previously treated patients: need for caution in interpreting results.  

PubMed

Xpert(®) MTB/RIF is the initial diagnostic test of choice for tuberculosis (TB). It is not known if false-positive results are more common in previously treated patients. We report four patients with successful treatment for TB up to 5 years previously who presented with respiratory tract infection and were Xpert-positive, but had negative TB cultures and clinical improvement without anti-tuberculosis treatment. We hypothesise that the Xpert results were false-positive due to the presence of dead Mycobacterium tuberculosis bacilli in lungs and sputum. Further work is required to determine the specificity of Xpert in previously treated patients. PMID:24902569

Boyles, T H; Hughes, J; Cox, V; Burton, R; Meintjes, G; Mendelson, M

2014-07-01

309

A Theory of False Cognitive Expectancies in Airline Pilots  

NASA Astrophysics Data System (ADS)

The Theory of False Cognitive Expectancies was developed by studying high reliability flight operations. Airline pilots depend extensively on cognitive expectancies to perceive, understand, and predict actions and events. Out of 1,363 incident reports submitted by airline pilots to the National Aeronautics and Space Administration Aviation Safety Reporting System over a year's time, 110 reports were found to contain evidence of 127 false cognitive expectancies in pilots. A comprehensive taxonomy was developed with six categories of interest. The dataset of 127 false expectancies was used to initially code tentative taxon values for each category. Intermediate coding through constant comparative analysis completed the taxonomy. The taxonomy was used for the advanced coding of chronological context-dependent visualizations of expectancy factors, known as strands, which depict the major factors in the creation and propagation of each expectancy. Strands were mapped into common networks to detect highly represented expectancy processes. Theoretical integration established 11 sources of false expectancies, the most common expectancy errors, and those conspicuous factors worthy of future study. The most prevalent source of false cognitive expectancies within the dataset was determined to be unconscious individual modeling based on past events. Integrative analyses also revealed relationships between expectancies and flight deck automation, unresolved discrepancies, and levels of situation awareness. Particularly noteworthy were the findings that false expectancies can combine in three possible permutations to diminish situation awareness and examples of how false expectancies can be unwittingly transmitted from one person to another. The theory resulting from this research can enhance the error coding process used during aircraft line oriented safety audits, lays the foundation for developing expectancy management training programs, and will allow researchers to proffer hypotheses for human testing using flight simulators.

Cortes, Antonio I.

310

Multiple Weather Factors Affect Apparent Survival of European Passerine Birds  

PubMed Central

Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for phenotypic and microevolutionary adaptations.

Salewski, Volker; Hochachka, Wesley M.; Fiedler, Wolfgang

2013-01-01

311

A FALSE POSITIVE FOR OCEAN GLINT ON EXOPLANETS: THE LATITUDE-ALBEDO EFFECT  

SciTech Connect

Identifying liquid water on the surface of planets is a high priority, as this traditionally defines habitability. One proposed signature of oceans is specular reflection ('glint'), which increases the apparent albedo of a planet at crescent phases. We post-process a global climate model of an Earth-like planet to simulate reflected light curves. Significantly, we obtain glint-like phase variations even though we do not include specular reflection in our model. This false positive is the product of two generic properties: (1) for modest obliquities, a planet's poles receive less orbit-averaged stellar flux than its equator, so the poles are more likely to be covered in highly reflective snow and ice; and (2) we show that reflected light from a modest-obliquity planet at crescent phases probes higher latitudes than at gibbous phases, therefore a planet's apparent albedo will naturally increase at crescent phase. We suggest that this 'latitude-albedo effect' will operate even for large obliquities: in that case the equator receives less orbit-averaged flux than the poles, and the equator is preferentially sampled at crescent phase. Using rotational and orbital color variations to map the surfaces of directly imaged planets and estimate their obliquity will therefore be a necessary pre-condition for properly interpreting their reflected phase variations. The latitude-albedo effect is a particularly convincing glint false positive for zero-obliquity planets, and such worlds are not amenable to latitudinal mapping. This effect severely limits the utility of specular reflection for detecting oceans on exoplanets.

Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Abbot, Dorian S. [Department of Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States); Voigt, Aiko [Max Planck Institute for Meteorology, Bundesstr. 53, D-20146, Hamburg (Germany)

2012-06-10

312

A False Positive for Ocean Glint on Exoplanets: The Latitude-Albedo Effect  

NASA Astrophysics Data System (ADS)

Identifying liquid water on the surface of planets is a high priority, as this traditionally defines habitability. One proposed signature of oceans is specular reflection ("glint"), which increases the apparent albedo of a planet at crescent phases. We post-process a global climate model of an Earth-like planet to simulate reflected light curves. Significantly, we obtain glint-like phase variations even though we do not include specular reflection in our model. This false positive is the product of two generic properties: (1) for modest obliquities, a planet's poles receive less orbit-averaged stellar flux than its equator, so the poles are more likely to be covered in highly reflective snow and ice; and (2) we show that reflected light from a modest-obliquity planet at crescent phases probes higher latitudes than at gibbous phases, therefore a planet's apparent albedo will naturally increase at crescent phase. We suggest that this "latitude-albedo effect" will operate even for large obliquities: in that case the equator receives less orbit-averaged flux than the poles, and the equator is preferentially sampled at crescent phase. Using rotational and orbital color variations to map the surfaces of directly imaged planets and estimate their obliquity will therefore be a necessary pre-condition for properly interpreting their reflected phase variations. The latitude-albedo effect is a particularly convincing glint false positive for zero-obliquity planets, and such worlds are not amenable to latitudinal mapping. This effect severely limits the utility of specular reflection for detecting oceans on exoplanets.

Cowan, Nicolas B.; Abbot, Dorian S.; Voigt, Aiko

2012-06-01

313

Sleep fragmentation and false memories during pregnancy and motherhood.  

PubMed

Pregnant women, both before and after childbirth, frequently experience memory deficits and disrupted sleep. In the present study we assessed the relationship between false memory generation and fragmented sleep during pregnancy and motherhood. We tested 178 pregnant women and 58 female non-pregnant childless controls, during pregnancy (15-35th week of gestation) and again after childbirth (8-13th month). False memories were defined as memories of gist words that were semantically related to studied word lists but were not presented during learning of these lists in the Deese-Roediger-McDermott (DRM) paradigm. Sleep was monitored by actigraphy in the home environment for seven consecutive nights. Compared to the controls, the group of pregnant women produced more false memories and displayed more fragmented sleep both during pregnancy and after childbirth. However, false memory generation was not correlated to measures of sleep fragmentation. These results show that pregnant women suffer from sleep fragmentation and a higher susceptibility to false memories, but leave open the question as to whether both phenomena are related. PMID:24589545

Berndt, Christiane; Diekelmann, Susanne; Alexander, Nina; Pustal, Anne; Kirschbaum, Clemens

2014-06-01

314

The principled control of false positives in neuroimaging  

PubMed Central

An incredible amount of data is generated in the course of a functional neuroimaging experiment. The quantity of data gives us improved temporal and spatial resolution with which to evaluate our results. It also creates a staggering multiple testing problem. A number of methods have been created that address the multiple testing problem in neuroimaging in a principled fashion. These methods place limits on either the familywise error rate (FWER) or the false discovery rate (FDR) of the results. These principled approaches are well established in the literature and are known to properly limit the amount of false positives across the whole brain. However, a minority of papers are still published every month using methods that are improperly corrected for the number of tests conducted. These latter methods place limits on the voxelwise probability of a false positive and yield no information on the global rate of false positives in the results. In this commentary, we argue in favor of a principled approach to the multiple testing problem—one that places appropriate limits on the rate of false positives across the whole brain gives readers the information they need to properly evaluate the results.

Wolford, George L.; Miller, Michael B.

2009-01-01

315

The role of sleep in false memory formation.  

PubMed

Memories are not stored as exact copies of our experiences. As a result, remembering is subject not only to memory failure, but to inaccuracies and distortions as well. Although such distortions are often retained or even enhanced over time, sleep's contribution to the development of false memories is unknown. Here, we report that a night of sleep increases both veridical and false recall in the Deese-Roediger-McDermott (DRM) paradigm, compared to an equivalent period of daytime wakefulness. But while veridical memory deteriorates across both wake and sleep, false memories are preferentially preserved by sleep, actually showing a non-significant improvement. The same selectivity of false over veridical memories was observed in a follow-up nap study. Unlike previous studies implicating deep, slow-wave sleep (SWS) in declarative memory consolidation, here veridical recall correlated with decreased SWS, a finding that was observed in both the overnight and nap studies. These findings lead to two counterintuitive conclusions - that under certain circumstances sleep can promote false memories over veridical ones, and SWS can be associated with impairment rather than facilitation of declarative memory consolidation. While these effects produce memories that are less accurate after sleep, these memories may, in the end, be more useful. PMID:19348959

Payne, Jessica D; Schacter, Daniel L; Propper, Ruth E; Huang, Li-Wen; Wamsley, Erin J; Tucker, Matthew A; Walker, Matthew P; Stickgold, Robert

2009-10-01

316

False recognition in Lewy-body disease and frontotemporal dementia.  

PubMed

The primary goal of this study was to evaluate the false recognition phenomenon in persons with frontotemporal dementia (FTD) and those with Lewy-body disease (LBD). Patients with LBD (n=10) or FTD (n=15) and their corresponding controls (n=30) were subjected to the Deese-Roediger-McDermott (DRM) paradigm to induce false recognition. Patients were first presented with items semantically related to a nonpresented critical target. The critical target was later included in a word list shown to patients to assess level of recognition. Both groups of patients showed a reduced level of false recognition of the critical target when controlling for their overall level of false alarms. This reduction was greater in persons with LBD than in those with FTD. Correlational analyses of performance on neuropsychological tests and the DRM variables indicated that the reduced DRM effect was associated with inhibition deficits in patients with LBD and with inhibition deficits and verbal memory in those with FTD. Our results support current models suggesting that these cognitive components contribute to the false recognition effect. PMID:21094574

de Boysson, C; Belleville, S; Phillips, N A; Johns, E K; Goupil, D; Souchay, C; Bouchard, R; Chertkow, H

2011-03-01

317

[False memories and aging: age effects on predictive inferences].  

PubMed

To study false memories in older adults, a lot of experiments used the DRM paradigm (Deese, Roediger et McDermott). Most of the time, the results showed that older adults make more false memories than young adults. To test this hypothesis with a more ecological material, we used a situation of text reading. When we read a text, we activate predictive inferences, which are anticipations of what will happen next. We constructed short texts inducing predictive inferences (represented by a target word not presented) to study false memories in young and older adults. For example, in the text , the target word "sting" is not presented but represents the predictive inference. After the reading of the texts, we propose to the subjects a restitution task consisting in recalling texts with the first sentence as clue. Then, they made a recognition task composed of target words and lures; they had to say if they remembered having read these words in the texts. In these two tasks, the subjects tended to remember not presented target words, creating false memories. This effect was the same for the two age groups showing that, in an ecological situation like text reading, older persons make as many false memories as young adults. PMID:19087911

Gras, Doriane; Tardieu, Hubert; Nicolas, Serge

2008-12-01

318

False memory and importance: can we prioritize encoding without consequence?  

PubMed

Given the large amount of information that we encounter, we often must prioritize what information we attempt to remember. Although critical for everyday functioning, relatively little research has focused on how people prioritize the encoding of information. Recent research has shown that people can and do selectively remember information assigned with higher, relative to lower, importance. However, the mechanisms underlying this prioritization process and the consequences of these processes are still not well understood. In the present study, we sought to better understand these prioritization processes and whether implementing these processes comes at the cost of memory accuracy, by increasing false memories. We used a modified form of the Deese/Roediger-McDermott (DRM) paradigm, in which participants studied DRM lists, with each list paired with low, medium, or high point values. In Experiment 1, encoding higher values led to more false memories than did encoding lower values, possibly because prioritizing information enhanced relational processing among high-value words. In Experiment 2, disrupting relational processing selectively reduced false memories for high-value words. Finally, in Experiment 3, facilitating relational processing selectively increased false memories for low-value words. These findings suggest that while prioritizing information can enhance true memory, this process concomitantly increases false memories. Furthermore, the mechanism underlying these prioritization processes depends on the ability to successfully engage in relational processing. Thus, how we prioritize the encoding of incoming information can come at a cost in terms of accurate memory. PMID:23576217

Bui, Dung C; Friedman, Michael C; McDonough, Ian M; Castel, Alan D

2013-10-01

319

Eliminating False-Positives in the Kepler Planet Catalog  

NASA Astrophysics Data System (ADS)

A primary goal of NASA's Kepler mission is the estimation of the frequency of exoplanets via the detection of planetary transits. Eliminating false-positives due primarily to diluted or grazing eclipsing binary stars is a critical component of such an estimate. This presentation will survey false-positive identification via analysis of Kepler pixels and light curves, as well as ground-based follow-up. We describe several methods we use to determine the location of a transit signal source from the Kepler pixels, and how the probability of a background false positive source is determined. Light curve analysis indicates whether the target star is itself an eclipsing binary. When ground-based spectra indicate that the target is a binary system that target is placed on a provisional false-positive list until it can be determined if the binary ephemeris is consistent with the observed transit. Ground-based high-resolution imaging is critical for the identification of background/foreground stars that may be the source of the transit. The results of these analyses are the Kepler false-positive table and a measure of confidence for the remaining Kepler planetary candidates. We will briefly survey the population of background binary stars detected by Kepler.

Bryson, Steve

2012-05-01

320

Apparent digestion and apparent retention of lipid and fatty acids in Atlantic cod ( Gadus morhua) fed increasing dietary lipid levels  

Microsoft Academic Search

The aim of the present study was to investigate how different dietary lipid levels affect growth, liver lipid deposition, apparent digestibility, apparent retention and utilization of total lipid and fatty acids in Atlantic cod. Individually tagged cod, with an average weight of 360 g, were randomly distributed in nine tanks, 49 fish per tank. Five diets with increasing dietary lipid level

Jon Øvrum Hansen; Gerd Marit Berge; Marie Hillestad; Åshild Krogdahl; Trina F. Galloway; Halvor Holm; Jørgen Holm; Bente Ruyter

2008-01-01

321

Glycopeptide Resistance in Coagulase-Negative Staphylococci  

Microsoft Academic Search

Coagulase-negative staphylococci (CNS) were the first organisms in which acquired glycopeptide resistance was recognized.\\u000a Ever since the early reports, it has been apparent that resistance to teicoplanin is more common than that to vancomycin and\\u000a that resistance occurs mostly in species such as Staphylococcus haemolyticus and Staphylococcus epidermidis. The minimum inhibitory concentrations (MICs) of teicoplanin for CNS usually fall over

F. Biavasco; C. Vignaroli; P. E. Varaldo

2000-01-01

322

Underestimation of prior remembering and susceptibility to false memories: two sides of the same coin?  

PubMed

In two studies, we explored whether susceptibility to false memories and the underestimation of prior memories (i.e., forgot-it-all-along effect) tap overlapping memory phenomena. Study 1 investigated this issue by administering the Deese/Roediger-McDermott task (DRM) and the forgot-it-all-along (FIA) task to an undergraduate sample (N=110). It was furthermore explored how performances on these tasks correlate with clinically relevant traits such as fantasy proneness, dissociative experiences, and cognitive efficiency. Results show that FIA and DRM performances are relatively independent from each other, suggesting that these measures empirically apparently refer to separate dimensions. However, they do not seem to define different profiles in terms of dissociation, fantasy proneness, and cognitive efficiency. Study 2 replicated the finding of relative independence between false memory propensity (as measured with the DRM task) and the underestimation of prior memories (as measured with an autobiographical memory dating task) in people with a history of childhood sexual abuse (N=35). PMID:21227719

Raymaekers, Linsey; Peters, Maarten J V; Smeets, Tom; Abidi, Latifa; Merckelbach, Harald

2011-12-01

323

Allelic Dropout Can Cause False-Positive Results for Prader-Willi and Angelman Syndrome Testing  

PubMed Central

The diagnosis of many genetic disorders relies on a combination of clinical suspicion and confirmatory genetic testing. Our laboratory uses a standard methylation-sensitive PCR (MSP) to target the differentially methylated SNRPN gene to test for Prader-Willi syndrome (PWS) and Angelman syndrome. One patient, a 27-month-old female, who lacked the classical clinical features of PWS, but had a molecular diagnosis of PWS by MSP by another laboratory, had repeat testing in our laboratory. Testing by MSP in our laboratory also identified an apparent loss of the unmethylated paternal allele, consistent with a diagnosis of PWS. Confirmatory testing using Southern blot analysis with a methylation-sensitive restriction enzyme showed a normal pattern of methylation, detecting both the methylated maternal and unmethylated paternal alleles. To investigate these discrepant results, we amplified and sequenced the SNRPN locus in this patient and identified a single nucleotide change within the binding site for the unmethylated DNA-specific primer. These results indicate this nucleotide change led to allelic dropout in the MSP analysis, yielding the false-positive result. Subsequently, MSP analysis using an alternate primer set that was developed by our laboratory detected both methylated and unmethylated alleles. These findings illustrate that allelic dropout due to the presence of rare polymorphisms can cause false-positive results in commonly used MSP assays and lead to molecular misdiagnosis.

Hussain Askree, Syed; Hjelm, Lawrence N.; Ali Pervaiz, Muhammad; Adam, Margaret; Bean, Lora J.H.; Hedge, Madhuri; Coffee, Bradford

2011-01-01

324

False positives in psychiatric diagnosis: implications for human freedom.  

PubMed

Current symptom-based DSM and ICD diagnostic criteria for mental disorders are prone to yielding false positives because they ignore the context of symptoms. This is often seen as a benign flaw because problems of living and emotional suffering, even if not true disorders, may benefit from support and treatment. However, diagnosis of a disorder in our society has many ramifications not only for treatment choice but for broader social reactions to the diagnosed individual. In particular, mental disorders impose a sick role on individuals and place a burden upon them to change; thus, disorders decrease the level of respect and acceptance generally accorded to those with even annoying normal variations in traits and features. Thus, minimizing false positives is important to a pluralistic society. The harmful dysfunction analysis of disorder is used to diagnose the sources of likely false positives, and propose potential remedies to the current weaknesses in the validity of diagnostic criteria. PMID:20232254

Wakefield, Jerome C

2010-02-01

325

Fate of the false monopoles: Induced vacuum decay  

NASA Astrophysics Data System (ADS)

We study a gauge theory model where there is an intermediate symmetry breaking to a metastable vacuum that breaks a simple gauge group to a U(1) factor. Such a model admits the existence of metastable magnetic monopoles, which we dub false monopoles. We prove the existence of these monopoles in the thin-wall approximation. We determine the instantons for the collective coordinate that corresponds to the radius of the monopole wall and we calculate the semiclassical tunneling rate for the decay of these monopoles. The monopole decay consequently triggers the decay of the false vacuum. As the monopole mass is increased, we find an enhanced rate of decay of the false vacuum relative to the celebrated homogeneous tunneling rate due to S. R. Coleman [Subnuclear seriesSUSEE4 13, 297 (1977).].

Kumar, Brijesh; Paranjape, M. B.; Yajnik, U. A.

2010-07-01

326

Left ventricular false tendons: anatomic, echocardiographic, and pathophysiologic insights.  

PubMed

Left ventricular (LV) false tendons are chordlike structures that traverse the LV cavity. They attach to the septum, to the papillary muscles, or to the free wall of the ventricle but not to the mitral valve. They are found in approximately half of human hearts examined at autopsy. Although it has been more than 100 years since their initial description, the functional significance of these structures remains largely unexplored. It has been suggested that they retard LV remodeling by tethering the walls to which they are attached, but there are few data to substantiate this. Some studies have suggested that false tendons reduce the severity of functional mitral regurgitation by stabilizing the position of the papillary muscles as the left ventricle enlarges. LV false tendons may also have deleterious effects and have been implicated in promoting membrane formation in discrete subaortic stenosis. This article reviews current understanding of the anatomy, echocardiographic characteristics, and pathophysiology of these structures. PMID:23602169

Silbiger, Jeffrey J

2013-06-01

327

Visual false memories in post-traumatic stress disorder (PTSD).  

PubMed

There is an ongoing debate whether or not patients with post-traumatic stress disorder (PTSD) are more prone to produce false memories. The present study investigated this question using a visual variant of the Deese-Roediger-McDermott (DRM) paradigm, additionally addressing underlying mechanisms of false memory production (e.g., depression, dissociation, emotional valence, arousal). The visual paradigm was administered to 48 traumatized individuals with (n=20) and without PTSD (n=28) and 28 non-traumatized controls. Groups did not differ with regard to memory performance and memory confidence. False memories were correlated with depression. We recommend that future studies employ trauma-related material to further explore memory aberrations in PTSD. PMID:19303587

Jelinek, Lena; Hottenrott, Birgit; Randjbar, Sarah; Peters, Maarten J; Moritz, Steffen

2009-06-01

328

The Effects of Repetition on Children's True and False Reports  

PubMed Central

As children are often called upon to provide testimony in court proceedings, determining the veracity of their statements is an important issue. In the course of investigation by police and social workers, children are often repeatedly interviewed about their experiences, though the impact of this repetition on children’s true and false statements remains largely unexamined. The current study analysed semantic differences in children’s truthful and fabricated statements about an event they had or had not participated in. Results revealed that children’s truthful and fabricated reports differed in linguistic content, and that their language also varied with repetition. Discriminant analyses revealed that with repetition, children’s true and false reports became increasingly difficult to differentiate using linguistic markers, though true reports were consistently classified correctly at higher rates than false reports. The implications of these findings for legal procedures concerning child witnesses are discussed.

Evans, Angela D.; Brunet, Megan K.; Talwar, Victoria; Bala, Nicholas; Lindsay, Rod C.L.; Lee, Kang

2013-01-01

329

Effectiveness of false correction strategy on science reading comprehension  

NASA Astrophysics Data System (ADS)

False-correction reading strategy theoretically prompted college students to activate their prior knowledge when provided false statements linked to a portion of their biology textbook. This strategy is based in elaborative interrogation theory, which suggests that prompting readers to answer interrogatives about text students are reading increases their comprehension of that text. These interrogatives always asked "why" statements pulled from a text, one sentence in length, were "true." True statements in this study based on a text were converted by the experimenter into false statements, one sentence in length. Students were requested to rewrite each statement (n=12) on average every 200 words in a text as they were reading, converting each false statement into a true statement. These students outperformed other students requested to reread the same biology text twice (an established placebo-control strategy). These students, in turn, outperformed still other students reading an unrelated control text taken from the same textbook used only to establish a prior knowledge baseline for all students included in this study. Students participating in this study were enrolled students in an undergraduate introductory general biology course designed for non-majors. A three-group, posttest-only, randomized experimental control-group design was used to prevent pretest activation of students' prior knowledge thus increasing chances of producing evidence of false-correction effectiveness and to begin augmenting potential generalizability to science classrooms. Students' (n=357) general biology knowledge, verbal ability, and attempts to use the false correction strategy were collected and analyzed. Eight of the participants were interviewed by the researcher in a first attempt in this domain to collect data on participants' points of view about the strategy. The results of this study are not yet recommended for use in authentic school settings as further research is indicated.

Ghent, Cynthia Anne

330

Product design and apparent usability. The influence of novelty in product appearance.  

PubMed

This research enhances our understanding of the relationship between aesthetics and usability by investigating the effects of novelty in product appearance on the apparent usability of a product. In two experimental studies using washing machines and digital cameras as stimuli, we systematically manipulated the level of novelty (low vs. high) in the product appearance by changing the product's color or shape. Participants were presented with one of these product appearances and a list of the product's technical specifications. Next, participants indicated how difficult or easy they expected the usage of the product to be. Our findings demonstrate that because people associate a high level of novelty with technological advancement, novelty in a product appearance negatively affects their expectations of a product's usability at the point of sale. Furthermore, novices are more likely to use the level of novelty as a cue for a product's apparent usability than experts. PMID:22512790

Mugge, Ruth; Schoormans, Jan P L

2012-11-01

331

False match elimination for face recognition based on SIFT algorithm  

NASA Astrophysics Data System (ADS)

The SIFT (Scale Invariant Feature Transform) is a well known algorithm used to detect and describe local features in images. It is invariant to image scale, rotation and robust to the noise and illumination. In this paper, a novel method used for face recognition based on SIFT is proposed, which combines the optimization of SIFT, mutual matching and Progressive Sample Consensus (PROSAC) together and can eliminate the false matches of face recognition effectively. Experiments on ORL face database show that many false matches can be eliminated and better recognition rate is achieved.

Gu, Xuyuan; Shi, Ping; Shao, Meide

2011-04-01

332

Beneficial effects of accurate and false brief biofeedback on relaxation.  

PubMed

Much research has focused on the efficacy of biofeedback therapy; however, previous studies only compared biofeedback treatment with no-treatment conditions or pre- and posttest data. Examination of biofeedback relaxation therapy with a false-feedback condition could produce data on physiological changes suitable to clarify findings. 63 participants were randomly assigned to either an accurate- or false-feedback condition for a 5-min. period. Analysis of the measures yielded significant differences in both groups between pre- and posttests, but not between groups, suggesting a potential placebo effect of biofeedback-induced relaxation. PMID:20178287

Strunk, Kamden K; Sutton, Geoffrey W; Burns, Nathan S

2009-12-01

333

Negative-ion states  

SciTech Connect

In this brief review, we discuss some of the properties of atomic and molecular negative ions and their excited states. Experiments involving photon reactions with negative ions and polar dissociation are summarized. 116 references, 14 figures.

Compton, R.N.

1982-01-01

334

Negative ion generator  

DOEpatents

A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions.

Stinnett, Regan W. (Albuquerque, NM)

1984-01-01

335

Negative ion generator  

DOEpatents

A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions. 8 figs.

Stinnett, R.W.

1984-05-08

336

Intravascular missile: apparent retrograde course from the left ventricle.  

PubMed Central

An air gun pellet was found in the right superior pulmonary vein after penetrating the left ventricle of a 14 year old boy. This apparent retrograde movement in the left side of the heart has not been reported previously. Images

Lamb, R K; Pawade, A; Prior, A L

1988-01-01

337

Apparent Ionic Charge in Electrolyte and Polyelectrolyte Solutions  

ERIC Educational Resources Information Center

Compares average displacements of charged particles under thermal motion alone with those obtained by the action of an external electric field to develop a concept of "apparent charge" to approximate actual structural charge in an electrolyte solution. (SL)

Magdelenat, H.; And Others

1978-01-01

338

Hypermethioninaemia and 3-Hydroxyisobutyric aciduria in an apparently healthy baby  

Microsoft Academic Search

An apparently healthy baby with persistent hypermethioninaemia excretes increased amounts of 3-hydroxyisobutyrate, 3-hydroxypropionate, -aminoisobutyrate and -alanine. A defect in the oxidation of methylmalonic and malonic semialdehydes is proposed but the cause of the hypermethioninaemia is obscure.

P. J. Congdon; D. Haigh; R. Smith; Anne Green; R. J. Pollitt

1981-01-01

339

Formation Mechanisms of Europan Ridges with Apparent Lateral Offsets  

Microsoft Academic Search

Evidence for both lateral shearing and orthogonal motion along Europan ridges indicates that apparent lateral offsets are not purely the result of strike-slip motions. We present an analysis of a band and ridge to determine their displacement ratios.

C. E. Bader; S. A. Kattenhorn

2008-01-01

340

Negative Ion Sources.  

National Technical Information Service (NTIS)

The status of research on hydrogen negative ion and heavy element sources is examined in this survey. The ranges of application and methods of producing negative ions are examined. Data on the production and annihilation cross sections of negative ions as...

M. A. Abroyan V. P. Golubev V. L. Komarov G. V. Chemyakin

1974-01-01

341

Triple Negative Breast Cancer  

MedlinePLUS

... to 10 PM EST. FACTS FOR LIFE Triple Negative Breast Cancer Who gets triple negative breast cancer? About 15-20 percent of all ... Women who have BRCA1 mutations What makes triple negative cancer unique? TNBC is less likely to be ...

342

Phonological False Memories in Children and Adults: Evidence for a Developmental Reversal  

ERIC Educational Resources Information Center

False memories created by the Deese/Roediger-McDermott (DRM) procedure typically show a developmental reversal whereby levels of false recall increase with age. In contrast, false memories produced by phonological lists have been shown to decrease as age increases. In the current study we show that phonological false memories, like semantic false

Swannell, Ellen R.; Dewhurst, Stephen A.

2012-01-01

343

When false recognition is unopposed by true recognition: Gist-based memory distortion in Alzheimer's disease  

Microsoft Academic Search

The authors examined false recognition of semantic associates in patients with probable Alzheimer's disease (AD), older adults, and young adults using a paradigm that provided rates of false recognition after single and multiple exposures to word lists. Using corrected false recognition scores to control for unrelated false alarms, the authors found that (a) the level of false recognition after a

Andrew E. Budson; Kirk R. Daffner; Rahul Desikan; Daniel L. Schacter

2000-01-01

344

Validity of False Belief Tasks in Blind Children  

ERIC Educational Resources Information Center

Previous studies have reported that congenitally blind children without any additional impairment reveal a developmental delay of at least 4 years in perspective taking based on testing first-order false-belief tasks. These authors interpret this delay as a sign of autism-like behavior. However, the delay may be caused by testing blind children…

Brambring, Michael; Asbrock, Doreen

2010-01-01

345

Counterfactual Conditionals and False Belief: A Developmental Dissociation  

ERIC Educational Resources Information Center

The objective of this study was to explore factors that affect the difficulty of counterfactual reasoning in 3-5-year-old children and to shed light on the reason why counterfactual reasoning relates to understanding false belief [Cognitive Development, 13 (1998) 73-90]. Using travel scenarios, the difference between simple scenarios, in which…

Perner, Josef; Sprung, Manuel; Steinkogler, Bettina

2004-01-01

346

Improved Variable Index constant false alarm rate radar processors  

Microsoft Academic Search

In the cases when the statistical distribution of range return samples are not known, constant false alarm rate (CFAR) processors can be used. Cell Averaging (CA) CFAR radar processors which have the best performance in Gaussian homogeneous environments, exhibits performance degradation in the presence of an interfering target or in regions of abrupt change in the backround clutter power. The

Y. C. U?n; K. M. U?ner

2010-01-01

347

A Competitive Nonverbal False Belief Task for Children and Apes  

ERIC Educational Resources Information Center

A nonverbal false belief task was administered to children (mean age 5 years) and two great ape species: chimpanzees ("Pan troglodytes") and bonobos ("Pan paniscus"). Because apes typically perform poorly in cooperative contexts, our task was competitive. Two versions were run: in both, a human competitor witnessed an experimenter hide a reward in…

Krachun, Carla; Carpenter, Malinda; Call, Josep; Tomasello, Michael

2009-01-01

348

Reducing False Positives in Runtime Analysis of Deadlocks.  

National Technical Information Service (NTIS)

This paper presents an improvement of a standard algorithm for detecting dead-lock potentials in multi-threaded programs, in that it reduces the number of false positives. The standard algorithm works as follows. The multi-threaded program under observati...

S. Bensalem K. Havelund

2002-01-01

349

Looking for Childhood Schizophrenia: Case Series of False Positives.  

ERIC Educational Resources Information Center

Extensive experience with the diagnosis of childhood-onset schizophrenia indicates a high rate of false positives. Most mislabeled patients have chronic disabling, affective, or behavioral disorders. The authors report the cases of three children who passed stringent initial childhood-onset schizophrenia "screens" but had no chronic psychotic…

Stayer, Catherine; Sporn, Alexandra; Gogtay, Nitin; Tossell, Julia; Lenane, Marge; Gochman, Peter; Rapoport, Judith L.

2004-01-01

350

Production of wormholes in the decay of the false vacuum  

SciTech Connect

Tunneling processes leading to the decay of the false vacuum are studied in the theory of a scalar field interacting with gravity. It is shown that in the theory with conformal coupling (the action containing the term (1/12)Rphi/sup 2/) bubbles with wormhole geometry can be produced, whereas this is impossible in the theory with minimal coupling.

Lavrelashvili, G.V.

1987-01-01

351

Counterfactual Thinking and False Belief: The Role of Executive Function  

ERIC Educational Resources Information Center

The purpose of the current study was to examine further the relationship between counterfactual thinking and false belief (FB) as examined by Guajardo and Turley-Ames ("Cognitive Development, 19" (2004) 53-80). More specifically, the current research examined the importance of working memory and inhibitory control in understanding the relationship…

Drayton, Stefane; Turley-Ames, Kandi J.; Guajardo, Nicole R.

2011-01-01

352

Detecting False Positives in Multielement Designs: Implications for Brief Assessments  

ERIC Educational Resources Information Center

The authors assessed the extent to which multielement designs produced false positives using continuous duration recording (CDR) and interval recording with 10-s and 1-min interval sizes. Specifically, they created 6,000 graphs with multielement designs that varied in the number of data paths, and the number of data points per data path, using a…

Bartlett, Sara M.; Rapp, John T.; Henrickson, Marissa L.

2011-01-01

353

Do 10-Month-Old Infants Understand Others' False Beliefs?  

ERIC Educational Resources Information Center

As adults, we know that others' mental states, such as beliefs, guide their behavior and that these mental states can deviate from reality. Researchers have examined whether young children possess adult-like theory of mind by focusing on their understanding about others' false beliefs. The present research revealed that 10-month-old infants seemed…

Luo, Yuyan

2011-01-01

354

False Choices: Why School Vouchers Threaten Our Children's Future.  

ERIC Educational Resources Information Center

A voucher system of schooling would destroy the few democratic gains made in public education in recent years, worsen inequalities that already permeate education, and block opportunities for meaningful reform. Articles included in this special issue are: (1) an introduction, "Why We Are Publishing False Choices" ("Rethinking Schools" Editorial…

Lowe, Robert, Ed.; Miner, Barbara, Ed.

1992-01-01

355

Avoiding False Claims of Child Sexual Abuse: Empty Promises.  

ERIC Educational Resources Information Center

Responds to previous article by Fincham, Beach, Moore, and Diener (this issue) on child sexual abuse. Focuses on importance of recognizing that attempts to reduce probability of false claims of child abuse would result in increasing probability of missing true claims of child abuse. Offers hypothesis-testing framework as useful heuristic for…

Pezdek, Kathy

1994-01-01

356

Robust Combinatorial Auction Protocol against False-Name Bids  

Microsoft Academic Search

This paper presents a new combinatorial auction protocol (LDS protocol) that is robust against false-name bids. Inter- net auctions have become an integral part of Electronic Com- merce (EC) and a promising field for applying agent and Ar- tificial Intelligence technologies. Although the Internet pro- vides an excellent infrastructure for combinatorial auctions, we must consider the possibility of a new

Makoto Yokoo; Yuko Sakurai; Shigeo Matsubara

2000-01-01

357

Reducing Child Witnesses' False Reports of Misinformation from Parents.  

ERIC Educational Resources Information Center

Explored whether source-monitoring training (SMT) would help 3- to 8-year-olds report only experienced events during a target interview. Found that SMT reduced 7- and 8- year-olds' false reports in response to direct questions but had no impact on younger children's performance. Findings suggest a transition between 3 and 8 years in strategic use…

Poole, Debra Ann; Lindsay, D. Stephen

2002-01-01

358

Observed changes in false springs over the contiguous United States  

NASA Astrophysics Data System (ADS)

warming fosters an earlier spring green-up that may bring potential benefits to agricultural systems. However, advances in green-up timing may leave early stage vegetation growth vulnerable to cold damage when hard freezes follow green-up resulting in a false spring. Spatiotemporal patterns of green-up dates, last spring freezes, and false springs were examined across the contiguous United States from 1920 to 2013. Results indicate widespread earlier green-up and last spring freeze dates over the period. Observed changes in these dates were asymmetric with the last spring freeze date advancing to earlier in the year relative to green-up date. Although regionally variable, these changes resulted in a reduction in false springs, notably over the past 20 years, except across the intermountain western United States where the advance in green-up timing outpaced that of the last spring freeze. A sensitivity experiment shows that observed decreases in false springs are consistent with a warming climate.

Peterson, Alexander G.; Abatzoglou, John T.

2014-03-01

359

Hyperspectral matched filter with false-alarm mitigation  

NASA Astrophysics Data System (ADS)

One of the fundamental challenges for a hyperspectral imaging surveillance system is the detection of sub-pixel objects in background clutter. The background surrounding the object, which acts as interference, provides the major obstacle to successful detection. One algorithm that is widely used in hyperspectral detection and successfully suppresses the background in many situations is the matched filter detector. However, the matched filter also produces false alarms in many situations. We use three simple and well-established concepts--the target-background replacement model, the matched filter, and Mahalanobis distance--to develop the matched filter with false alarm mitigation (MF-FAM), a dual-threshold detector capable of eliminating many matched filter false alarms. We compare this algorithm to the mixture tuned matched filter (MTMF), a popular approach to matched filter false alarm mitigation found in the ENVI® software environment. The two algorithms are shown to produce nearly identical results using real hyperspectral data, but the MF-FAM is shown to be operationally, computationally, and theoretically simpler than the MTMF.

Dipietro, Robert S.; Manolakis, Dimitris G.; Lockwood, Ronald B.; Cooley, Thomas; Jacobson, John

2012-01-01

360

Narrative dependency and the false belief task in autism  

Microsoft Academic Search

Several studies have used a cognitive approach to teaching people with autism to pass false belief tasks with a broader aim of developing theory of mind abilities. However, these tasks have certain executive features that may influence performance on the tasks and the potential for generalization. The study examines the influence of narrative support and language level on the ability

Evelyn McGregor; Mark Bennett

2008-01-01

361

Do 15-Month-Old Infants Understand False Beliefs?  

Microsoft Academic Search

For more than two decades, researchers have argued that young children do not understand mental states such as beliefs. Part of the evidence for this claim comes from preschoolers' failure at verbal tasks that require the understanding that others may hold false beliefs. Here, we used a novel nonverbal task to examine 15-month-old infants' ability to predict an actor's behavior

Kristine H. Onishi; Renée Baillargeon

2005-01-01

362

Are Young Children Susceptible to the False-Memory Illusion?  

ERIC Educational Resources Information Center

Three studies investigated the extent to which kindergartners, second-graders, and undergraduates were susceptible to the Deese/Roediger/McDermott (DRM) illusion, an adult false-memory paradigm. Findings indicated that the DRM illusion was at nearly non-existent levels in young children, and was still below adult levels in adolescence. The low…

Brainerd, C. J.; Reyna, V. F.; Forrest, T. J.

2002-01-01

363

Young Children's Emerging Ability to Make False Statements  

ERIC Educational Resources Information Center

This study examined the origins of children's ability to make consciously false statements, a necessary component of lying. Children 2 to 5 years of age were rewarded for claiming that they saw a picture of a bird when viewing pictures of fish. They were asked outcome questions ("Do you win/lose?"), recognition questions ("Do you have a…

Ahern, Elizabeth C.; Lyon, Thomas D.; Quas, Jodi A.

2011-01-01

364

Clean: A false alarm reduction method for SAR CCD  

Microsoft Academic Search

Synthetic Aperture Radar Coherent Change Detection (SAR CCD) is a sensitive change detector capable of finding ground surface height changes on the order of a radar wavelength. While this detector is capable of finding small changes such as tire tracks left on the ground, it is fraught with false alarms. This paper introduces a new algorithm, the Clutter Location, Estimation,

Rhonda D. Phillips

2011-01-01

365

Healthier Eating Could Be Just a False Memory Away  

Microsoft Academic Search

In two experiments, involving 231 subjects, we planted the suggestion that subjects loved to eat asparagus as children. Relative to controls, subjects receiving the suggestion became more confident that they had loved asparagus the first time they tried it. These new (false) beliefs had consequences for those who formed them, including increased general liking of asparagus, greater desire to eat

Cara Laney; Erin K. Morris; Daniel M. Bernstein; Briana M. Wakefield; Elizabeth F. Loftus

366

Matched False-Belief Performance during Verbal and Nonverbal Interference  

ERIC Educational Resources Information Center

Language has been shown to play a key role in the development of a child's theory of mind, but its role in adult belief reasoning remains unclear. One recent study used verbal and nonverbal interference during a false-belief task to show that accurate belief reasoning in adults necessarily requires language (Newton & de Villiers, 2007). The…

Dungan, James; Saxe, Rebecca

2012-01-01

367

The Multiple True-False Item Format: A Status Review.  

ERIC Educational Resources Information Center

Literature related to the multiple true-false (MTF) item format is reviewed. Each answer cluster of a MTF item may have several true items and the correctness of each is judged independently. MTF tests appear efficient and reliable, although they are a bit harder than multiple choice items for examinees. (SLD)

Frisbie, David A.

1992-01-01

368

Context Effects and False Memory for Alcohol Words in Adolescents  

PubMed Central

This study assessed incidental recognition of Alcohol and Neutral words in adolescents who encoded the words under distraction. Participants were 171 (81 male) 10th grade students, ages 14–16 (M = 15.1) years. Testing was conducted by telephone: Participants listened to a list containing Alcohol and Neutral (Experimental – Group E, n = 92) or only Neutral (Control – Group C, n = 79) words, while counting backwards from 200 by two’s. Recognition was tested immediately thereafter. Group C exhibited higher false recognition of Neutral than Alcohol items, whereas Group E displayed equivalent false rates for both word types. The reported number of alcohol TV ads seen in the past week predicted higher false recognition of Neutral words in Group C and of Alcohol words in Group E. False memory for Alcohol words in Group E was greater in males and high anxiety sensitive participants. These context-dependent biases may contribute to exaggerations in perceived drinking norms previously found to predict alcohol misuse in young drinkers.

Zack, Martin; Sharpley, Justin; Dent, Clyde W.; Stacy, Alan W.

2011-01-01

369

An Improved Comprehensive Model for the Apparent Viscosity of Blood  

NASA Astrophysics Data System (ADS)

An improved comprehensive model for the apparent viscosity of blood is developed and used in simulations of the microcirculation in capillary bundles of rat spinotrapezius muscle fascia. In the microcirculation, the apparent viscosity of blood depends on the local vessel diameter, hematocrit, and shear rate. The proposed comprehensive model extends the apparent viscosity model developed by Pries, Secomb, Gaehtgens, and Gross (Circulation Research, 67, 826-834, 1990), which describes the effect of vessel diameter and hematocrit on the apparent viscosity. A shear thinning term is developed using the experimental data of Lipowsky, Usami, and Chien (Microvascular Research, 19, 297-319, 1980). Curve fits of this data can be combined with equations given in the Pries et al. work to create a system of equations that can be used to find the shear thinning factor. The simulations based on the improved apparent viscosity model use realistic vessel topology for the microvasculature, reconstructed from microscope images of tissue samples, and consider passive and active vessel properties. The numerical method is based on a Hagen-Poiseuille balance in the microvessels and a sparse matrix solver is used to obtain the solution. It was found that the inclusion of the shear factor decreases the overall flowrate in the capillary bundle. Many vessel connections in the fascia are characterized by relatively low shear rates and therefore increased apparent viscosity.

Jacobitz, Frank; Anderson, Spencer

2008-11-01

370

Variability of apparent particle density of an urban aerosol.  

PubMed

The day to day and diurnal variation of apparent particle density was studied using highly time-resolved measurements of particle number distribution and fine-particle mass concentration. The study was conducted in Erfurt, Germany, from January 1, 1999, to November 22, 2000. A setup consisting of a differential mobility particle spectrometer and a laser aerosol spectrometer was used for particle number distribution measurements. PM2.5 particle mass was measured in parallel on an hourly basis using a tapered element oscillating microbalance (TEOM) and on daily base by using a Harvard marple impactor (HI). For the estimation of the mean apparent density of particles, number size distributions were converted into volume size distributions, assuming that the particles were spherically shaped. The volume size distributions were integrated over the range of 10 nm to 2.03 microm Stokes equivalent diameter to obtain volume concentrations. Mean apparent particle density was calculated as ratio of mass concentration and volume concentration. The mean apparent particle density, determined from HI and number size distribution on a daily basis was 1.6 +/- 0.5 g cm(-3). We found a strong day-to-day variation of apparent density ranging from 1.0 to 2.5 g cm(-3) (5th and 95th percentile). Furthermore, the apparent density showed pronounced diurnal pattern both in summer and in winter and also on weekdays and weekends. The apparent density was lowest in the morning and highest in the afternoon. The mean apparent density on an hourly basis was 1.4 +/- 0.5 and 1.5 +/- 0.5 g cm(-3) for PM2.5TEOM and corrected PM2.5TEOM using regression equation between daily mass concentration of HI and TEOM, respectively. The strong diurnal variation of apparent particle density was associated predominantly with the vertical temperature inversion and with traffic intensity. Thus, the apparent particle density depends on the physical particle properties and might be related to chemical composition of the sampled particle. PMID:14572082

Pitz, Mike; Cyrys, Josef; Karg, Erwin; Wiedensohler, Alfred; Wichmann, H Erich; Heinrich, Joachim

2003-10-01

371

45 CFR 2540.610 - What are the consequences of making a false or misleading statement?  

Code of Federal Regulations, 2010 CFR

...Welfare 4 2010-10-01 2010-10-01 false What are the consequences of making a false or misleading statement? 2540.610 Section...SERVICE GENERAL ADMINISTRATIVE PROVISIONS False or Misleading Statements § 2540.610...

2010-10-01

372

45 CFR 2540.610 - What are the consequences of making a false or misleading statement?  

Code of Federal Regulations, 2010 CFR

...Welfare 4 2009-10-01 2009-10-01 false What are the consequences of making a false or misleading statement? 2540.610 Section...SERVICE GENERAL ADMINISTRATIVE PROVISIONS False or Misleading Statements § 2540.610...

2009-10-01

373

47 CFR 80.335 - Procedures for canceling false distress alerts.  

Code of Federal Regulations, 2012 CFR

... false Procedures for canceling false distress alerts. 80.335 Section 80.335 Telecommunication...335 Procedures for canceling false distress alerts. If a distress alert is inadvertently transmitted, the following...

2012-10-01

374

47 CFR 80.335 - Procedures for canceling false distress alerts.  

Code of Federal Regulations, 2010 CFR

... false Procedures for canceling false distress alerts. 80.335 Section 80.335 Telecommunication...335 Procedures for canceling false distress alerts. If a distress alert is inadvertently transmitted, the following...

2010-10-01

375

47 CFR 80.335 - Procedures for canceling false distress alerts.  

Code of Federal Regulations, 2011 CFR

... false Procedures for canceling false distress alerts. 80.335 Section 80.335 Telecommunication...335 Procedures for canceling false distress alerts. If a distress alert is inadvertently transmitted, the following...

2011-10-01

376

47 CFR 80.335 - Procedures for canceling false distress alerts.  

Code of Federal Regulations, 2013 CFR

... false Procedures for canceling false distress alerts. 80.335 Section 80.335 Telecommunication...335 Procedures for canceling false distress alerts. If a distress alert is inadvertently transmitted, the following...

2013-10-01

377

Assessing the Significance of Apparent Correlations between Radio and Gamma-Ray Blazar Fluxes  

NASA Astrophysics Data System (ADS)

Whether or not a correlation exists between the radio and gamma-ray flux densities of blazars is a long-standing question, and one that is difficult to answer confidently because of various observational biases, which may either dilute or apparently enhance any intrinsic correlation between radio and gamma-ray luminosities. We introduce a novel method of data randomization to evaluate quantitatively the effect of these biases and to assess the intrinsic significance of an apparent correlation between radio and gamma-ray flux densities of blazars. The novelty of the method lies in a combination of data randomization in luminosity space (to ensure that the randomized data are intrinsically, and not just apparently, uncorrelated) and significance assessment in flux space (to explicitly avoid Malmquist bias and automatically account for the limited dynamical range in both frequencies). The method is applicable even to small samples that are not selected with strict statistical criteria. For larger samples we describe a variation of the method in which the sample is split in redshift bins, and the randomization is applied in each bin individually; this variation is designed to yield the equivalent to luminosity-function sampling of the underlying population in the limit of very large, statistically complete samples. We show that for a smaller number of redshift bins, the method yields a worse significance, and in this way it is conservative: although it may fail to confirm an existing intrinsic correlation in a small sample that cannot be split into many redshift bins, it will not assign a stronger, artificially enhanced significance. We demonstrate how our test performs as a function of number of sources, strength of correlation, and number of redshift bins used, and we show that while our test is robust against common-distance biases and associated false positives for uncorrelated data, it retains the power of other methods in rejecting the null hypothesis of no correlation for correlated data.

Pavlidou, V.; Richards, J. L.; Max-Moerbeck, W.; King, O. G.; Pearson, T. J.; Readhead, A. C. S.; Reeves, R.; Stevenson, M. A.; Angelakis, E.; Fuhrmann, L.; Zensus, J. A.; Giroletti, M.; Reimer, A.; Healey, S. E.; Romani, R. W.; Shaw, M. S.

2012-06-01

378

ASSESSING THE SIGNIFICANCE OF APPARENT CORRELATIONS BETWEEN RADIO AND GAMMA-RAY BLAZAR FLUXES  

SciTech Connect

Whether or not a correlation exists between the radio and gamma-ray flux densities of blazars is a long-standing question, and one that is difficult to answer confidently because of various observational biases, which may either dilute or apparently enhance any intrinsic correlation between radio and gamma-ray luminosities. We introduce a novel method of data randomization to evaluate quantitatively the effect of these biases and to assess the intrinsic significance of an apparent correlation between radio and gamma-ray flux densities of blazars. The novelty of the method lies in a combination of data randomization in luminosity space (to ensure that the randomized data are intrinsically, and not just apparently, uncorrelated) and significance assessment in flux space (to explicitly avoid Malmquist bias and automatically account for the limited dynamical range in both frequencies). The method is applicable even to small samples that are not selected with strict statistical criteria. For larger samples we describe a variation of the method in which the sample is split in redshift bins, and the randomization is applied in each bin individually; this variation is designed to yield the equivalent to luminosity-function sampling of the underlying population in the limit of very large, statistically complete samples. We show that for a smaller number of redshift bins, the method yields a worse significance, and in this way it is conservative: although it may fail to confirm an existing intrinsic correlation in a small sample that cannot be split into many redshift bins, it will not assign a stronger, artificially enhanced significance. We demonstrate how our test performs as a function of number of sources, strength of correlation, and number of redshift bins used, and we show that while our test is robust against common-distance biases and associated false positives for uncorrelated data, it retains the power of other methods in rejecting the null hypothesis of no correlation for correlated data.

Pavlidou, V.; Richards, J. L.; Max-Moerbeck, W.; King, O. G.; Pearson, T. J.; Readhead, A. C. S.; Reeves, R.; Stevenson, M. A. [California Institute of Technology, Owens Valley Radio Observatory, Pasadena, CA 91125 (United States); Angelakis, E.; Fuhrmann, L.; Zensus, J. A. [Max-Planck-Institut fuer Radioastronomie, Bonn 53121 (Germany); Giroletti, M. [INAF Istituto di Radioastronomia, Bologna (Italy); Reimer, A. [Institut fuer Astro- und Teilchenphysik and Institut fuer Theoretische Physik, Leopold-Franzes-Universitaet Innsbruck, Innsbruck,Austria (Austria); Healey, S. E.; Romani, R. W.; Shaw, M. S. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States)

2012-06-01

379

False Paradoxes of Superposition in Electric and Acoustic Waves.  

ERIC Educational Resources Information Center

Corrected are several misconceptions concerning the apparently "missing" energy that results when acoustic or electromagnetic waves cancel by destructive interference and the wave impedance reflected to the sources of the wave energy changes so that the input power is reduced. (Author/CS)

Levine, Richard C.

1980-01-01

380

Reflection and transmission at the apparent horizon during gravitational collapse  

SciTech Connect

We examine the wave functionals describing the collapse of a self-gravitating dustball in an exact quantization of the gravity-dust system. We show that ingoing (collapsing) dust shell modes outside the apparent horizon must necessarily be accompanied by outgoing modes inside the apparent horizon, whose amplitude is suppressed by the square root of the Boltzmann factor at the Hawking temperature. Likewise, ingoing modes in the interior must be accompanied by outgoing modes in the exterior, again with an amplitude suppressed by the same factor. A suitable superposition of the two solutions is necessary to conserve the dust probability flux across the apparent horizon; thus, each region contains both ingoing and outgoing dust modes. If one restricts oneself to considering only the modes outside the apparent horizon then one should think of the apparent horizon as a partial reflector, the probability for a shell to reflect being given by the Boltzmann factor at the Hawking temperature determined by the mass contained within it. However, if one considers the entire wave function, the outgoing wave in the exterior is seen to be the transmission through the horizon of the interior outgoing wave that accompanies the collapsing shells. This transmission could allow information from the interior to be transferred to the exterior.

Vaz, Cenalo [RWC, University of Cincinnati, Cincinnati, Ohio 45221-0011 (United States); Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221-0011 (United States); Wijewardhana, L. C. R. [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221-0011 (United States)

2010-10-15

381

Modality effect in false recognition: evidence from Chinese characters.  

PubMed

Using the Deese/Roediger-McDermott (DRM) false memory method, Smith and Hunt ( 1998 ) first reported the modality effect on false memory and showed that false recall from DRM lists was lower following visual study than following auditory study, which led to numerous studies on the mechanism of modality effect on false memory and provided many competing explanations. In the present experiment, the authors tested the modality effect in false recognition by using a blocked presentation condition and a random presentation condition. The present experiment found a modality effect different from the results of the previous research; namely, false recognition was shown to be greater following visual study than following auditory study, especially in the blocked presentation condition rather than in the random presentation condition. The authors argued that this reversed modality effect may be due to different encoding and processing characteristics between Chinese characters and English words. Compared with English words, visual graphemes of critical lures in Chinese lists are likely to be activated and encoded in participants' minds, thus it is more difficult for participants to discriminate later inner graphemes from those items presented in visual modality. Hence visual presentation could lead to more false recognition than auditory presentation in Chinese lists. The results in the present experiment demonstrated that semantic activation occurring during the encoding and retrieve phases played an important role in modality effect in false recognition, and our findings might be explained by the activation-monitoring account. Utilisant la méthode de fausse mémoire de Deese/Roediger-McDermott (DRM), Smith et Hunt ( 1998 ) ont d'abord rendu compte de l'effet de modalité sur la fausse mémoire et ils ont montré que le faux rappel à partir des listes de DRM était plus faible suivant une étude visuelle plutôt qu'une étude auditive. Ceci a mené à plusieurs études sur le mécanisme de l'effet de modalité sur la fausse mémoire, lesquelles ont fourni plusieurs explications concurrentes. Dans la présente expérience, les auteurs ont testé l'effet de modalité dans la fausse reconnaissance en utilisant une condition de présentation fixe et une condition de présentation aléatoire. Cette expérience a révélé un effet de modalité différent des résultats obtenus dans les recherches antérieures. En effet, la fausse reconnaissance était plus élevée suivant une étude visuelle plutôt qu'une étude auditive, spécialement dans la condition de présentation fixe. Les auteurs suggèrent que cet effet de modalité inverse peut être dû à des caractéristiques d'encodage et de processus différentes entre les caractères chinois et les mots anglais. Comparativement aux mots anglais, les graphèmes visuels des leurres critiques dans les listes chinoises sont susceptibles d'être activés et encodés dans l'esprit des participants, rendant plus difficile de discriminer les graphèmes intériorisés plus tard de ces items présentés dans la modalité visuelle. Ainsi, la présentation visuelle pourrait mener à davantage de fausse reconnaissance que la présentation auditive dans les listes chinoises. Les résultats de la présente expérience ont démontré que l'activation sémantique se produisait durant l'encodage et que la phase de retrait jouait un rôle important dans l'effet de modalité dans la fausse reconnaissance. Nos résultats peuvent être expliqués par la théorie activation-contrôle. Utilizando el método de Deese/Roediger-McDermott (DRM) de falsa mamoria, Smith y Hunt ( 1998 ) fueron los primeros en encontrar el efecto de modalidad en la falsa memoria y demostraron que los falsos recuerdos del listado DRM fueron más bajos después de un estudio visual que después de un estudio auditivo lo cual llevó a varios estudios sobre el mecanismo del efecto de la modalidad sobre falsos recuerdos y proporcionó varias explicaciones que compiten entre sí. En el presente trabajo, los autores estudiaron el efect

Mao, Wei Bin; Yang, Zhi Liang; Wang, Lin Song

2010-02-01

382

The cognitive neuroscience of true and false memories.  

PubMed

Of central relevance to the recovered/false memory debate is understanding the factors that cause us to believe that a mental experience is a memory of an actual past experience. According to the source monitoring framework (SMF), memories are attributions that we make about our mental experiences based on their subjective qualities, our prior knowledge and beliefs, our motives and goals, and the social context. From this perspective, we discuss cognitive behavioral studies using both objective (e.g., recognition, source memory) and subjective (e.g., ratings of memory characteristics) measures that provide much information about the encoding, revival and monitoring processes that yield both true and false memories. The chapter also considers how neuroimaging findings, especially from functional magnetic resonance imaging studies, are contributing to our understanding of the relation between memory and reality. PMID:22303763

Johnson, Marcia K; Raye, Carol L; Mitchell, Karen J; Ankudowich, Elizabeth

2012-01-01

383

Gravitational wave background and Higgs false vacuum inflation  

NASA Astrophysics Data System (ADS)

For a narrow band of values of the top quark and Higgs boson masses, the standard model Higgs potential develops a shallow local minimum at energies of about 1016 GeV, where primordial inflation could have started in a cold metastable state. For each point of that band, the highness of the Higgs potential at the false minimum is calculable, and there is an associated prediction for the inflationary gravitational wave background, namely, for the tensor to scalar ratio r. We show that the recent measurement of r by the BICEP2 collaboration, r =0.16-0.05+0.06 at 1?, combined with the most up-to-date measurements of the top quark and Higgs boson masses, reveals that the hypothesis that a standard model shallow false minimum was the source of inflation in the early Universe is viable.

Masina, Isabella

2014-06-01

384

Looking for Childhood Schizophrenia: Case Series of False Positives  

Microsoft Academic Search

Extensive experience with the diagnosis of childhood-onset schizophrenia indicates a high rate of false positives. Most mislabeled patients have chronic disabling, affective, or behavioral disorders. The authors report the cases of three children who passed stringent initial childhood-onset schizophrenia “screens” but had no chronic psychotic disorder. For two, the European literature yielded more fitting diagnoses: psychosis not otherwise specified (e.g.,

CATHERINE STAYER; ALEXANDRA SPORN; NITIN GOGTAY; JULIA TOSSELL; MARGE LENANE; PETER GOCHMAN; JUDITH L RAPOPORT

2004-01-01

385

False-vacuum decay in generalized extended inflation  

NASA Technical Reports Server (NTRS)

False-vacuum decay was studied in context of generalized extended inflationary theories, and the bubble nucleation rates was computed for these theories in the limit of G(sub N) yields 0. It was found that the time dependence of the nucleation rate can be exponentially strong through the time dependence of the Jordan-Brans-Dicke field. This can have a pronounced effect on whether extended inflation can be successfully implemented.

Holman, Richard; Kolb, Edward W.; Vadas, Sharon L.; Wang, Yun

1990-01-01

386

Counterfactual thinking and false belief: The role of executive function  

Microsoft Academic Search

The purpose of the current study was to examine further the relationship between counterfactual thinking and false belief (FB) as examined by Guajardo and Turley-Ames (Cognitive Development, 19 (2004) 53–80). More specifically, the current research examined the importance of working memory and inhibitory control in understanding the relationship between counterfactual thinking and FB. Participants were 3-, 4-, and 5-year-olds (N=76).

Stefane Drayton; Kandi J. Turley-Ames; Nicole R. Guajardo

2011-01-01

387

False-alarm probability of conventional and logarithmic CFAR receivers  

NASA Astrophysics Data System (ADS)

In a radar system, it is well known that the conventional and logarithmic CFAR techniques after a square-law detector are effective for Rayleigh clutter. In order to apply CFAR techniques to practical radar systems with a linear detector, false-alarm probability was calculated by a Monte Carlo simulation on computer for a finite number of samples N. It is concluded that the conventional CFAR receiver is superior to the logarithmic CFAR receiver.

Tatsukawa, S.; Sekine, M.; Musha, T.

1984-10-01

388

Statistical inference and data mining: false discoveries control  

Microsoft Academic Search

Data Mining is characterized by its ability at processing large amounts of data. Among those are the data “features”- variables\\u000a or association rules that can be derived from them. Selecting the most interesting features is a classical data mining problem.\\u000a That selection requires a large number of tests from which arise a number of false discoveries. An original non parametric

Stéphane Lallich; Olivier Teytaud; Elie Prudhomme

389

``False Positive,'' an Apt Term and Concept for Volcanologists  

Microsoft Academic Search

A less-than-bold prediction is that signals that could presage an eruption, but later turn out not to have been predictive (false positives), will continue to vex volcanologists and societies touched by volcanic processes. At present, even at the most carefully monitored volcanoes, many remote-sensing, geophysical, and geochemical clues are often incompletely diagnostic. Even assessing multiple kinds of data cannot ensure

R. Wunderman

2010-01-01

390

On the false discovery rates of a frequentist: Asymptotic expansions  

Microsoft Academic Search

Consider a testing problem for the null hypothesis $H_0:\\\\theta\\\\in\\\\Theta_0$. The standard frequentist practice is to reject the null hypothesis when the p-value is smaller than a threshold value $\\\\alpha$, usually 0.05. We ask the question how many of the null hypotheses a frequentist rejects are actually true. Precisely, we look at the Bayesian false discovery rate $\\\\delta_n=P_g(\\\\theta\\\\in\\\\Theta_0|p-value<\\\\alpha)$ under a proper

Anirban DasGupta; Tonglin Zhang

2006-01-01

391

[False aneurysm on dacron prosthesis, 20 years after aortofemoral bypass].  

PubMed

A 85-year-old male developed a false, non septic, non anastomotic aneurysm, 20 years after right aorto-femoral Dacron grafting for claudication. On account of the proximity to the femoral anastomosis, and the association with a profunda femoris stenosis, a conventional surgical repair was preferred to an endovascular treatment. The patient underwent a successful aneurysm resection followed by PTFE interposition between the primary graft and the profunda femoris artery, with uneventful recovery. PMID:11692765

Illuminati, G; Bertagni, A; Nasti, A G; Montesano, G

2001-10-01

392

Apparent Temperature and Air Pollution vs. Elderly Population Mortality in Metro Vancouver  

PubMed Central

Background Meteorological conditions and air pollution in urban environments have been associated with general population and elderly mortality, showing seasonal variation. Objectives This study is designed to evaluate the relationship between apparent temperature (AT) and air pollution (PM2.5) vs. mortality in elderly population of Metro Vancouver. Methods Statistical analyses are performed on moving sum daily mortality rates vs. moving average AT and PM2.5 in 1-, 2-, 3-, 5-, and 7-day models for all seasons, warm temperatures above 15°C, and cold temperatures below 10°C. Results Approximately 37% of the variation in all-season mortality from circulatory and respiratory causes can be explained by the variation in 7-day moving average apparent temperature (r2?=?0.37, p<0.001). Although the analytical results from air pollution models show increasingly better prediction ability of longer time-intervals (r2?=?0.012, p<0.001 in a 7-day model), a very weak negative association between elderly mortality and air pollution is observed. Conclusions Apparent temperature is associated with mortality from respiratory and circulatory causes in elderly population of Metro Vancouver. In a changing climate, one may anticipate to observe potential health impacts from the projected high- and particularly from the low-temperature extremes.

Krstic, Goran

2011-01-01

393

Emergence asynchrony between herbivores leads to apparent competition in the field.  

PubMed

It has been established that herbivore populations can be structured by apparent competition, even if they do not compete directly for resources. But we lack evidence on the mechanisms behind such indirect competition. This study shows that temporal asynchronies in emergence time lead to apparent competition via shared natural enemies in a leafminer-parasitoid community. We present three kinds of evidence on mechanisms driving apparent competition. First, we conducted a two-year population census of Liriomyza helianthi and Calycomyza platyptera, along with all associated parasitoids, at seven sites in the Californian Central Valley, USA. We then assessed C. platyptera parasitism on 16 vegetation islands, half with experimental removal of early-season L. helianthi populations. Finally, we examined parasitoid host preference between leafminer species. We found that Liriomyza helianthi populations emerged approximately one month before C. platyptera. Experimental removal of L. helianthi populations in the early summer led to a 60% reduction in parasitism of C. platyptera. We found no evidence of differential parasitoid preference for host species. The findings suggest that temporal asynchrony can lead to negative effects on later-emerging species and that such indirect competition may be a major structuring force in herbivore communities. PMID:22164825

Blitzer, Eleanor J; Welter, Stephen C

2011-11-01

394

Negative ions in comets  

NASA Technical Reports Server (NTRS)

Negative ion sources in comets are identified and cometary plasma effects caused by negative ions are examined. The primary negative ion sources are shown to be: (1) for the inner coma - photodissociation of HCN, electron attachment of OH, and collision with alkalis; (2) in the vicinity of the nucleus - interplanetary dust collisions with the nucleus; and (3) for both the contaminated solar wind region and sporadic discharges in the nonhomogeneous inner coma plasma - dissociative electron attachment and charge inversion during keV positive ion scattering by cometary dust. Negative ion abundance for Halley's Comet has been estimated to be 10 to the -6th - 10 to the -10th of electron densities.

Wekhof, A.

1981-01-01

395

Negative Ion Density Fronts  

SciTech Connect

Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

Igor Kaganovich

2000-12-18

396

SETI pulse detection algorithm: Analysis of false-alarm rates  

NASA Technical Reports Server (NTRS)

Some earlier work by the Search for Extraterrestrial Intelligence (SETI) Science Working Group (SWG) on the derivation of spectrum analyzer thresholds for a pulse detection algorithm based on an analysis of false alarm rates is extended. The algorithm previously analyzed was intended to detect a finite sequence of i periodically spaced pulses that did not necessarily occupy the entire observation interval. This algorithm would recognize the presence of such a signal only if all i-received pulse powers exceeded a threshold T(i): these thresholds were selected to achieve a desired false alarm rate, independent of i. To simplify the analysis, it was assumed that the pulses were synchronous with the spectrum sample times. This analysis extends the earlier effort to include infinite and/or asynchronous pulse trains. Furthermore, to decrease the possibility of missing an extraterrestrial intelligence signal, the algorithm was modified to detect a pulse train even if some of the received pulse powers fall below the threshold. The analysis employs geometrical arguments that make it conceptually easy to incorporate boundary conditions imposed on the derivation of the false alarm rates. While the exact results can be somewhat complex, simple closed form approximations are derived that produce a negligible loss of accuracy.

Levitt, B. K.

1983-01-01

397

False-positive urine pregnancy tests--clinicians as detectives.  

PubMed

Reliably diagnosing pregnancy in women presenting with nonspecific abdominal pain can be lifesaving. If diagnostic tests are unreliable, however, valuable time and resources can be wasted pursuing unnecessary and potentially harmful interventions. After four false positive-urine pregnancy tests in one week, we began investigating the laboratory's entire process involving the UPreg tests. We discovered that, as is common in resource-poor settings, the laboratory repeatedly reused test tubes. We found that the false-positive tests resulted from performing the UPreg tests in test tubes that were improperly cleaned and, for the most part, had been used immediately beforehand to test women coming into the maternity ward. Sufficient residua from the pregnant women's high ß-HCG levels had remained in the test tubes to cause subsequent false-positive results in our emergency ward patients. Although pregnancy can now be reliably diagnosed with inexpensive, disposable and simple tests, these tests must not only be used properly, but also, when used in the laboratory, be accompanied by appropriate cleaning and quality-control procedures. This is particularly essential in resource-constrained environments. PMID:22121449

Valenzuela, Rolando; Iserson, Kenneth V; Punguyire, Damien

2011-01-01

398

Do children "DRM" like adults? False memory production in children.  

PubMed

The Deese/Roediger-McDermott (DRM) paradigm was used to investigate developmental trends in accurate and false memory production. In Experiment 1, DRM lists adjusted to be more consistent with children's vocabulary were used with 2nd graders, 8th graders, and college students. Accurate and false recall and recognition increased with age, but semantic information appeared to be available to all age groups. Experiment 2 created a set of child-generated lists based on the free associations by a group of 3rd graders to critical items. The child-generated associates were different from those generated by adults; long and short versions of the child-generated lists were therefore presented to 2nd, 5th, and 8th graders and college students in Experiment 3. Second graders exhibited few false memories, whereas 5th graders were similar to adults in low-demand conditions and more similar to younger children in high-demand conditions. Findings are discussed in terms of developmental changes in automatic and effortful processing and the use of semantic networks. PMID:18194015

Metzger, Richard L; Warren, Amye R; Shelton, Jill T; Price, Jodi; Reed, Andrea W; Williams, Danny

2008-01-01

399

False belief and the refusal of medical treatment.  

PubMed Central

May a doctor treat a patient, despite that patient's refusal, when in his professional opinion treatment is necessary? This is the dilemma which must from time to time confront most physicians. An examination of the validity of such a refusal is provided by the present authors who use the case history of a patient refusing treatment, for cancer as well as for a fractured hip, to evaluate the grounds for intervention in such circumstances. In such a situation the patient is said to have a 'false belief' and it is the doctor's duty to try to change that belief in the patient's interest. The false belief is considered here in terms of the liberty principle, the patient's mental competence and on what is called the 'harm principle' (harm to other individuals or to society). Finally the concept of paternalism is examined. The authors conclude that the doctor must attempt to change a false belief, and if this fails he must examine the patient's mental competence to make the decision to refuse treatment. But in the last analysis the doctor may be under an obligation to respect the patient's refusal. Readers might like to look at (or read again) the papers on 'Liberty' and 'Conscience' published in this Journal under the heading Analysis.

Faden, R; Faden, A

1977-01-01

400

Role of surface in apparent viscosity of glasses  

NASA Astrophysics Data System (ADS)

Two problems have intrigued experts for a long time: The one is within the context of the legend of flowing cathedral glass windows and the second is the inaccuracy appearing in very old thermometers of famous scientists. We relate this with the role of the surface on the apparent viscosity of glasses. The apparent viscosity could deviate from the bulk viscosity if the fraction w of the surface molecules, of small samples, is sufficiently large. The effect is more prominent at low temperatures, correspondingly at high viscosities. The interpretation is within the Avramov and Milchev viscosity model, combined with the predictions of the change of heat capacity for extremely small samples. We find that the apparent glass transition temperature could depend on the sample size, in agreement with experimental observations existing in the literature. In addition to glasses, the present results could be of importance for thin films and foams.

Avramov, I.

2014-03-01

401

Apparent suicidal carbon monoxide poisonings with concomitant prescription drug overdoses.  

PubMed

We report four separate suicides by apparent motor vehicle-related carbon monoxide (CO) poisoning in which complete toxicological analysis showed the absence of, or lower than expected, percent carboxyhemoglobin saturation and high concentrations of concomitant prescription drugs. These cases, within a population of 71 apparent CO suicides from the Wayne County Medical Examiner's Office over 1998-2004, represent cases where additional factors are in play. Multiple modalities (CO poisoning and drug overdose) and/or undetectable carbon dioxide poisoning from the vehicle exhaust of cars manufactured after laws regulating vehicle emissions were enacted are examples of additional factors that require consideration in these selected cases. All four cases demonstrated some degree of decomposition, so the possible loss of CO could not be ruled out. The need for full toxicological analysis in apparent suicidal CO poisoning is emphasized. PMID:16419412

Gupta, Avneesh; Pasquale-Styles, Melissa A; Hepler, Bradford R; Isenschmid, Daniel S; Schmidt, Carl J

2005-10-01

402

On apparent temperature in low-frequency Alfvenic turbulence  

SciTech Connect

Low-frequency, parallel propagating Alfvenic turbulence in collisionless plasmas is theoretically studied. Alfvenic turbulence is derived as an equilibrium state (Beltrami field) in the magnetohydrodynamic equations with the pressure anisotropy and multi-species of ions. It is shown that the conservation of the total 'apparent temperature' corresponds to the Bernoulli law. A simple model of the radially expanding solar wind including Alfvenic turbulence is also discussed. The conversion of the wave energy in the 'apparent temperature' into the 'real temperature' is facilitated with increasing radial distance.

Nariyuki, Yasuhiro [Faculty of Human Development, University of Toyama, 3190, Toyama City, Toyama 930-8555 (Japan)

2012-08-15

403

Frequency, phase, and colour coding in apparent motion.  

PubMed

We present some results which indicate that the known spatiotemporal limits for apparent motion are consistent with the motion being sinusoidal or a result of filtering. Given this we investigated how two such motions interact as a function of their relative temporal phase differences. This was accomplished by inducing two independent motions from complementary coloured event pairs. Results indicated critical phase limits for perceiving the two motions (red and green) which were consistent with the frequency specificity of the effect. The results are discussed within the framework of a filtering process for the perception of apparent motion. PMID:432081

Caelli, T; Finlay, D

1979-01-01

404

Apparent /sup 15/N uptake kinetics resulting from remineralization  

SciTech Connect

A computer model of phytoplankton /sup 15/N uptake experiments in which simultaneous remineralization is occurring is used to demonstrate potential artifacts if remineralization is disregarded. In simulated experiments where a range of /sup 15/N additions is made to obtain population kinetics, apparent kinetics can be obtained where none exist. Similarly, in simulated experiments where samples are taken over time there is an apparent decrease in uptake rates with time, which, when plotted against inferred changes in substrate concentration, gives rise to similar kinetics. In actual experiments, such artifacts could obscure any real kinetics and would lead to erroneous estimates of population characteristics.

Garside, C.

1984-01-01

405

The addiction to negativity.  

PubMed

In this paper, we have described a type of resistance that has attracted increasing psychoanalytic attention in recent years. Patients exposed to intense negativity during early life may develop an addiction to negative experience as adolescents and adults, and this may constitute a central organizing feature of their personality. In almost all patients, however, some moments of negativity may be observed. We have traced the developmental origins of an attachment to negativity, drawing especially on psychoanalytic investigations of preoedipal pathology. Manifestations and derivatives of early negativity include anhedonia, attachment to physical pain, fear of success, masochism, deprivation of self and others, and negative voyeurism. In discussing the dynamic functions of negativity, we place particular emphasis on two motives: the patient's desires for revenge against early objects that have been a source of deprivation and frustration; and the defensive function of negativity in helping to express as well as ward off dangerous wishes to merge with the object. Deviant forms of autoerotism are likely to be used by these patients to deal with the reactivation of early experiences of neglect and rejection. When negativity is used as a defense or method of relating to others it can lead to a severe disruption of the psychotherapeutic relationship. We have reviewed suggestions for the management of extreme negativity in treatment. Resolution of the therapist's countertransference reactions, especially induced feelings of frustration, rage, and helplessness, is crucial. Emphasis also has been placed on the patient's desires for revenge against self and object, and the manner in which these may be understood and eventually resolved. Only when patient and therapist begin to investigate the adaptive functions of extreme negativity can this pathological symptom be resolved and the patient's awareness of self and sense of autonomy be enhanced. PMID:1763149

Lane, R C; Hull, J W; Foehrenbach, L M

1991-01-01

406

What factors underlie children's susceptibility to semantic and phonological false memories? Investigating the roles of language skills and auditory short-term memory.  

PubMed

Two experiments investigated the cognitive skills that underlie children's susceptibility to semantic and phonological false memories in the Deese/Roediger-McDermott procedure (Deese, 1959; Roediger & McDermott, 1995). In Experiment 1, performance on the Verbal Similarities subtest of the British Ability Scales (BAS) II (Elliott, Smith, & McCulloch, 1997) predicted correct and false recall of semantic lures. In Experiment 2, performance on the Yopp-Singer Test of Phonemic Segmentation (Yopp, 1988) did not predict correct recall, but inversely predicted the false recall of phonological lures. Auditory short-term memory was a negative predictor of false recall in Experiment 1, but not in Experiment 2. The findings are discussed in terms of the formation of gist and verbatim traces as proposed by fuzzy trace theory (Reyna & Brainerd, 1998) and the increasing automaticity of associations as proposed by associative activation theory (Howe, Wimmer, Gagnon, & Plumpton, 2009). PMID:24632322

McGeown, Sarah P; Gray, Eleanor A; Robinson, Jamey L; Dewhurst, Stephen A

2014-06-01

407

A meningomyelocele with normal intracranial signs on ultrasound and false-negative amniotic fluid alpha-fetoprotein and acetylcholinesterase  

PubMed Central

Neural tube defects are the major targets of prenatal diagnoses, along with Down syndrome. Prenatal diagnosis of spina bifida is possible at second trimester of gestation through ?-fetoprotein and acetylcholinesterase biochemistry assays and ultrasound. In particular, the discovery of characteristic intracranial signs on ultrasound leads to a very high diagnosis rate. However, it is rare for spina bifida to present without intracranial signs while also showing normal values of maternal serum ?-fetoprotein, amniotic fluid ?-fetoprotein, and acetylcholinesterase. In our hospital, a fetus with spina bifida was delivered at 37+5 weeks' gestation by cesarean section, and was continually followed up over 2 years to date.

Yoon, Chong Hyeok; Kang, Sang Kyu; Jin, Chan Hee; Park, Moon Sun

2014-01-01

408

USE OF ICC/PCR AND NUCLEIC ACID SEQUENCING TO OVERCOME FALSE NEGATIVE RESULTS IN ENVIRONMENTAL VIRUS SURVEYS. (R824756)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

409

A meningomyelocele with normal intracranial signs on ultrasound and false-negative amniotic fluid alpha-fetoprotein and acetylcholinesterase.  

PubMed

Neural tube defects are the major targets of prenatal diagnoses, along with Down syndrome. Prenatal diagnosis of spina bifida is possible at second trimester of gestation through ?-fetoprotein and acetylcholinesterase biochemistry assays and ultrasound. In particular, the discovery of characteristic intracranial signs on ultrasound leads to a very high diagnosis rate. However, it is rare for spina bifida to present without intracranial signs while also showing normal values of maternal serum ?-fetoprotein, amniotic fluid ?-fetoprotein, and acetylcholinesterase. In our hospital, a fetus with spina bifida was delivered at 37+5 weeks' gestation by cesarean section, and was continually followed up over 2 years to date. PMID:24883294

Yoon, Chong Hyeok; Kang, Sang Kyu; Jin, Chan Hee; Park, Moon Sun; Rho, Jeong Hoon

2014-05-01

410

Negative ion detachment processes  

SciTech Connect

This paper discusses the following topics: H{sup {minus}} and D{sup {minus}} collisions with atomic hydrogen; collisional decomposition of SF{sub 6}{sup {minus}}; two-electron loss processes in negative ion collisions; associative electron detachment; and negative ion desorption from surfaces.

Champion, R.L.; Doverspike, L.D.

1990-10-01

411

Positive, Zero, or Negative?  

NSDL National Science Digital Library

This lesson involves students using positive and negative numbers to represent quantities in real-world contexts, explaining the meaning of zero in each situation. Students will understand the positive and negative numbers are used together to describe quantities having opposite values.

Brown, Kathleen

2012-09-16

412

Communicating with Negative People  

Microsoft Academic Search

We all must have been negative at work at one time or another and most of us didn't like to be that way. For some people it is a way of being. Some people seem to flourish in a negative atmosphere. Often people defend their right to be nasty as their legitimate duty. Do Emergency Communications Centers have an over-abundance

Adriana Vintean

2007-01-01

413

Thymoma and parathyroid adenoma: false-positive imaging and intriguing laboratory test results.  

PubMed

IMPORTANCE Parathyroid hormone (PTH)-secreting thymomas are an exceedingly rare entity. A PTH-secreting thymoma was discovered in the workup of a patient with primary hyperparathyroidism. A concomitant parathyroid adenoma was removed from the same patient. We present the intriguing clinical course and review the literature on this rare entity. In addition, we discuss the use of scanning with technetium Tc 99m sestamibi, the PTH assay, and cervical ultrasonography in the workup of a parathyroid adenoma. OBSERVATIONS Scanning with technetium Tc 99m sestamibi demonstrated false-positive uptake of the mediastinal thymoma and false-negative uptake of the true cervical parathyroid adenoma. After removal of the thymoma, the parathyroid adenoma demonstrated appropriate uptake on a follow-up scan. After removal of the parathyroid adenoma, the hyperparathyroidism was cured. CONCLUSIONS AND RELEVANCE Given the extremely rare incidence of a PTH-secreting thymoma with a concurrent parathyroid adenoma, we do not recommend alterations in the diagnostic algorithm for primary hyperparathyroidism. However, in this case, the need for 2 separate operations may have been avoided by obtaining an ultrasonogram to further explore the findings on the technetium Tc 99m sestamibi scan. We recommend that both studies be considered in unclear cases of primary hyperparathyroidism. PMID:24557446

Cunningham, Lauren C; Yu, Jun-Ge; Shilo, Konstantin; Tang, Bingfeng; Nair, Lekshmi; Daniel, Vincent C; Old, Matthew O

2014-04-01

414

Analysis of the apparent friction of polymeric surfaces  

Microsoft Academic Search

The apparent friction coefficient is the ratio between the tangential force and the normal load applied to moving body in contact with the surface of a material. This coefficient includes a so-called “true local friction” at the interface and a “geometrical friction” which is the ploughing effect. The material underneath a moving tip may display various types of behaviour: elastic,

S. Lafaye; C. Gauthier; R. Schirrer

2006-01-01

415

Product design enhancement using apparent usability and affective quality  

Microsoft Academic Search

In this study, apparent usability and affective quality were integrated in a design framework called the Usability Perception and Emotion Enhancement Model (UPEEM). The UPEEM was validated using structural equation modeling (SEM). The methodology consists of four phases namely product selection, attribute identification, design alternative generation, and design alternative evaluation. The first stage involved the selection of a product that

Rosemary R. Seva; Katherine Grace T. Gosiaco; Ma. Crea Eurice D. Santos; Denise Mae L. Pangilinan

2011-01-01

416

Apparent slip between metal and rubber-covered pressure rollers  

Microsoft Academic Search

Measurements are described which indicate that in a roller system consisting of a metal and a rubber-covered roller rotating in contact under load, the metal roller always has the higher apparent peripheral speed whether it is driving or is driven by the rubber roller. This behaviour is similar to that observed when a wheel or cylinder is rolled over a

G J Parish

1958-01-01

417

The apparent velocity and acceleration of relativistically moving objects  

Microsoft Academic Search

Although special relativity limits the actual velocity of a particle to $c$, the velocity of light, the observed velocity need not be the same as the actual velocity as the observer is only aware of the position of a particle at the time in the past when it emits the detected signal. We consider the apparent speed and acceleration of

Austen Berlet; Dennis G. C. McKeon; Farrukh Chishtie; Martin Houde

2011-01-01

418

Sudden cardiac death in young people with apparently normal heart  

Microsoft Academic Search

Objective: The aim of the present study was to assess the prevalence of subtle morphologic substrates, clinically unrecognizable, underlying sudden cardiac death (SCD) in young people with apparently normal heart. Methods: In the time interval 1979-1998, 273 consecutive cases of SCD in young people (#35 years) which occurred in the Veneto Region of Italy were prospectively studied. Following exclusion of

Domenico Corrado; Cristina Basso; Gaetano Thiene

419

A scale of apparent intensity of electric shock  

Microsoft Academic Search

By the method of magnitude estimation, Ss having no previous experience in judging electric shock made numerical estimations of the apparent intensity of an electric current applied through salt-water electrodes to the fingers of one hand. To a first approximation, these magnitude estimations determine a power function in which subjective intensity S is related to current I by S =

S. S. Stevens; A. S. Carton; G. M. Shickman

1958-01-01

420

Apparent damage accumulation in cancellous bone using neural networks.  

PubMed

In this paper, a neural network model is developed to simulate the accumulation of apparent fatigue damage of 3D trabecular bone architecture at a given bone site during cyclic loading. The method is based on five steps: (i) performing suitable numerical experiments to simulate fatigue accumulation of a 3D micro-CT trabecular bone samples taken from proximal femur for different combinations of loading conditions; (ii) averaging the sample outputs in terms of apparent damage at whole specimen level based on local tissue damage; (iii) preparation of a proper set of corresponding input-output data to train the network to identify apparent damage evolution; (iv) training the neural network based on the results of step (iii); (v) application of the neural network as a tool to estimate rapidly the apparent damage evolution at a given bone site. The proposed NN model can be incorporated into finite element codes to perform fatigue damage simulation at continuum level including some morphological factors and some bone material properties. The proposed neural network based multiscale approach is the first model, to the author's knowledge, that incorporates both finite element analysis and neural network computation to rapidly simulate multilevel fatigue of bone. This is beneficial to develop enhanced finite element models to investigate the role of damage accumulation on bone damage repair during remodelling. PMID:21616468

Hambli, Ridha

2011-08-01

421

Apparent damage accumulation in cancellous bone using neural networks  

Microsoft Academic Search

In this paper, a neural network model is developed to simulate the accumulation of apparent fatigue damage of 3D trabecular bone architecture at a given bone site during cyclic loading. The method is based on five steps: (i) performing suitable numerical experiments to simulate fatigue accumulation of a 3D micro-CT trabecular bone samples taken from proximal femur for different combinations

Ridha Hambli

2011-01-01

422

Apparent yield stress measurement in cemented paste backfill  

Microsoft Academic Search

The effect of specimen composition on the apparent yield stress of cemented paste backfill (CPB) is studied using a Brookfield rotational viscometer with vane geometry. The factors that are assessed include binder type and content, selected chemical admixtures (superplasticizers) and pore fluid chemistry (e.g. ionic concentration and pH). The difficulties associated with performing viscosity measurements on high solids content mixtures

Dragana Simon; Murray Grabinsky

2012-01-01

423

Real and apparent changes in sediment deposition rates through time  

Microsoft Academic Search

Field measurements show that estimated sediment deposition rate decreases as a power law function of the measurement interval. This apparent decrease in sediment deposition has been attributed to completeness of the sedimentary record; the effect arises because of incorporation of longer hiatuses in deposition as averaging time is increased. We demonstrate that a heavy-tailed distribution of periods of nondeposition (hiatuses)

Rina Schumer; Douglas J. Jerolmack

2009-01-01

424

Determination of apparent activation energy of concrete by isothermal calorimetry  

Microsoft Academic Search

In recent works at our laboratory, instrumentations have been developed to carry out calorimetric tests on concrete in isothermal conditions, which give much information. The objective of this article is, on the basis of this technique, to study the validity of the Arrhenius law and to determine the evolution of apparent activation energy of the concrete. This parameter is necessary

H. Kada-Benameur; E. Wirquin; B. Duthoit

2000-01-01

425

Effects of feeding high carbohydrate or fat diets. 2. Apparent digestibility and apparent metabolizable energy of the posthatch poult.  

PubMed

An experiment was conducted with turkey poults to determine the apparent digestibility and derivation of ME from diets containing a high proportion of carbohydrate from corn (CHO; 60% of diet) or 10%) supplemental fat from an animal-vegetable blended fat (FAT) or a synthetic medium-chain triglyceride (MCT). Poults fed the FAT diet consumed more feed from 6 to 8 and 9 to 11 d of age than poults fed the CHO diet, intake of the MCT diet was intermediate. From 3 to 11 d of age, the percentage apparent digestibility of nonlipid DM by poults fed the CHO diet was greater than that observed for either the FAT or MCT diets (P < or = 0.05). The percentage apparent digestibility of lipid was consistently greater for poults fed the MCT diet (> or = 90%) and could be attributed to the high apparent digestibility of C8:0 (>95%), which accounted for 76% of total MCT dietary fatty acids. Over the course of the experiment, the mean percentage apparent digestibility of lipid in the CHO and FAT diets was 76.4 and 70.8%, respectively, and did not change with increasing age. The lower percentage apparent digestibility of lipid in the CHO and FAT diets was attributed to the low apparent digestibility of C16:0 (70.4, 52.7%) and C18:0 (58.4, 26.8%), respectively. The apparent digestibility of the polyunsaturated fatty acids, C18:2 (n-6) and C18:3 (n-3), was consistently high and ranged from 72 to 85% and 81 to 88%, respectively. The CHO diet resulted in an approximate 6% increase in determined AMEn compared with either the FAT or MCT diets. The results of this study showed that commercial feed-grade fats are poorly digested by very young poults. The digestibility of polyunsaturated fatty acids, however, was shown to be quite high, and the data suggest that vegetable oils containing high proportions of polyunsaturated fatty acids or alternative fat sources containing high proportions of medium-chain fatty acids could be well utilized by the very young poult. PMID:10560832

Turner, K A; Applegate, T J; Lilburn, M S

1999-11-01

426

The illusion of the positive: the impact of natural and induced mood on older adults' false recall.  

PubMed

Recent research suggests that affective and motivational processes can influence age differences in memory. In the current study, we examine the impact of both natural and induced mood state on age differences in false recall. Older and younger adults performed a version of the Deese-Roediger-McDermott (DRM; Roediger & McDermott, 1995 , Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803) false memory paradigm in either their natural mood state or after a positive or negative mood induction. Results indicated that, after accounting for age differences in basic cognitive function, age-related differences in positive mood during the testing session were related to increased false recall in older adults. Inducing older adults into a positive mood also exacerbated age differences in false memory. In contrast, veridical recall did not appear to be systematically influenced by mood. Together, these results suggest that positive mood states can impact older adults' information processing and potentially increase underlying cognitive age differences. PMID:22292431

Emery, Lisa; Hess, Thomas M; Elliot, Tonya

2012-11-01

427

Apparent temperature dependence on localized atmospheric water vapor  

NASA Astrophysics Data System (ADS)

The atmosphere is a critical factor in remote sensing. Radiance from a target must pass through the air column to reach the sensor. The atmosphere alters the radiance reaching the sensor by attenuating the radiance from the target via scattering and absorption and by introducing an upwelling radiance. In the thermal infrared, these effects will introduce errors in the derived apparent temperature of the target if not properly accounted for. The temperature error is defined as the difference between the target leaving apparent temperature and observed apparent temperature. The effects of the atmosphere must be understood in order to develop methods to compensate for this error. Different atmospheric components will affect the radiation passing through it in different ways. Certain components may be more important than others depending on the remote sensing application. The authors are interested in determining the actual temperature of the superstructure that composes a mechanical draft cooling tower (MDCT), hence water vapor is the primary constituent of concern. The tower generates a localized water vapor plume located between the target and sensor. The MODTRAN radiative transfer code is used to model the effects of a localized exhaust plume from a MDCT in the longwave infrared. The air temperature and dew point depression of the plume and the thickness of the plume are varied to observe the effect on the apparent temperature error. In addition, the general atmospheric conditions are varied between two standard MODTRAN atmospheres to study any effect that ambient conditions have on the apparent temperature error. The Digital Imaging and Remote Sensing Image Generation (DIRSIG) modeling tool is used to simulate the radiance reaching a thermal sensor from a target after passing through the water vapor plume. The DIRSIG results are validated against the MODTRAN results. This study shows that temperature errors of as much as one Kelvin can be attributed to the presence of a localized water vapor plume.

Montanaro, Matthew; Salvaggio, Carl; Brown, Scott D.; Messinger, David W.; Garrett, Alfred J.

2008-05-01

428

False Memory for Trauma-Related DRM Lists in Adolescents and Adults with Histories of Child Sexual Abuse  

PubMed Central

The purpose of the present research was to examine Deese-Roediger-McDermott (DRM) false memory for trauma-related and nontrauma-related lists in adolescents and adults with and without documented histories of child sexual abuse (CSA). Individual differences in psychopathology and adult attachment were also explored. Participants were administered free recall and recognition tests after hearing CSA, negative, neutral, and positive DRM lists. In free recall, CSA and negative lists produced the most false memory. In sharp contrast, for recognition, CSA lists enjoyed the highest d’ scores. CSA-group adolescents who evinced greater PTSD symptoms had higher rates of false memory compared to: 1) nonCSA-group adolescents with higher PTSD symptom scores (free recall), and 2) CSA-group adolescents with lower PTSD symptom scores (recognition). Regression analyses revealed that individuals with higher PTSD scores and greater fearful-avoidant attachment tendencies showed less proficient memory monitoring for CSA lists. Implications for trauma and memory development and for translational research are discussed.

Goodman, Gail S.; Ogle, Christin M.; Block, Stephanie D.; Harris, LaTonya S.; Larson, Rakel P.; Augusti, Else-Marie; Cho, Young Il; Beber, Jonathan; Timmer, Susan; Urquiza, Anthony

2014-01-01

429

Understanding of Speaker Certainty and False-Belief Reasoning: A Comparison of Japanese and German Preschoolers  

ERIC Educational Resources Information Center

It has been repeatedly shown that when asked to identify a protagonist's false belief on the basis of his false statement, English-speaking 3-year-olds dismiss the statement and fail to attribute to him a false belief. In the present studies, we tested 3-year-old Japanese children in a similar task, using false statements accompanied by…

Matsui, Tomoko; Rakoczy, Hannes; Miura, Yui; Tomasello, Michael

2009-01-01

430

Realistic artificial DNA sequences as negative controls for computational genomics  

PubMed Central

A common practice in computational genomic analysis is to use a set of ‘background’ sequences as negative controls for evaluating the false-positive rates of prediction tools, such as gene identification programs and algorithms for detection of cis-regulatory elements. Such ‘background’ sequences are generally taken from regions of the genome presumed to be intergenic, or generated synthetically by ‘shuffling’ real sequences. This last method can lead to underestimation of false-positive rates. We developed a new method for generating artificial sequences that are modeled after real intergenic sequences in terms of composition, complexity and interspersed repeat content. These artificial sequences can serve as an inexhaustible source of high-quality negative controls. We used artificial sequences to evaluate the false-positive rates of a set of programs for detecting interspersed repeats, ab initio prediction of coding genes, transcribed regions and non-coding genes. We found that RepeatMasker is more accurate than PClouds, Augustus has the lowest false-positive rate of the coding gene prediction programs tested, and Infernal has a low false-positive rate for non-coding gene detection. A web service, source code and the models for human and many other species are freely available at http://repeatmasker.org/garlic/.

Caballero, Juan; Smit, Arian F. A.; Hood, Leroy; Glusman, Gustavo

2014-01-01

431

Realistic artificial DNA sequences as negative controls for computational genomics.  

PubMed

A common practice in computational genomic analysis is to use a set of 'background' sequences as negative controls for evaluating the false-positive rates of prediction tools, such as gene identification programs and algorithms for detection of cis-regulatory elements. Such 'background' sequences are generally taken from regions of the genome presumed to be intergenic, or generated synthetically by 'shuffling' real sequences. This last method can lead to underestimation of false-positive rates. We developed a new method for generating artificial sequences that are modeled after real intergenic sequences in terms of composition, complexity and interspersed repeat content. These artificial sequences can serve as an inexhaustible source of high-quality negative controls. We used artificial sequences to evaluate the false-positive rates of a set of programs for detecting interspersed repeats, ab initio prediction of coding genes, transcribed regions and non-coding genes. We found that RepeatMasker is more accurate than PClouds, Augustus has the lowest false-positive rate of the coding gene prediction programs tested, and Infernal has a low false-positive rate for non-coding gene detection. A web service, source code and the models for human and many other species are freely available at http://repeatmasker.org/garlic/. PMID:24803667

Caballero, Juan; Smit, Arian F A; Hood, Leroy; Glusman, Gustavo

2014-08-01

432

Bilateral eyelid erythema associated with false eyelash glue.  

PubMed

We report an unusual case of bilateral eyelid erythema caused by eyelash glue. A 22-year-old woman presented with a 3-day history of bilateral eyelid dermatitis after attaching false eyelashes by using latex-containing glue. Slit-lamp examination revealed erythema and swelling of the upper lids of both eyes. The skin prick test was positive for eyelash glue and her total tear IgE score was high. To the best of our knowledge, this is the first report of bilateral eyelid dermatitis caused by eyelash glue. PMID:22519514

Mimura, Tatsuya

2013-03-01

433

Distribution of extant populations of Quadrula mitchelli (false spike)  

USGS Publications Warehouse

The False Spike, Quadrula mitchelli (Simpson 1896), is a rare species of mussel endemic to Central Texas and the Rio Grande drainage (Howells 2010). This species was thought to have been extinct until the discovery of several live individuals in the Guadalupe River and a fresh dead individual in the San Saba River in 2011 (Randklev et al. 2012; Randklev et al. in press). Since then, this species has been reported at several other locations within its historic range (Sowards et al. in press; Tsakiris and Randklev 2013; Mabe and Kennedy 2013). Here, we report on the current known distribution of this species.

Randklev, Charles R.; Tsakiris, Eric; Howells, Robert G.; Groce, Julie; Johnson, Matthew S.; Bergmann, Joseph; Robertson, Clint; Blair, Andy; Littrell, Brad; Johnson, Nathan

2013-01-01

434

False vacuum decay in Jordan-Brans-Dicke cosmologies  

NASA Technical Reports Server (NTRS)

The bubble nucleation rate in a first-order phase transition taking place in a background Jordan-Brans-Dicke cosmology is examined. The leading order terms in the nucleation rate when the Jordan-Brans-Dicke field is large (i.e., late times) are computed by means of a Weyl rescaling of the fields in the theory. It is found that despite the fact that the Jordan-Brans-Dicke field (hence the effective gravitational constant) has a time dependence in the false vacuum at late times the nucleation rate is time independent.

Holman, Richard; Kolb, Edward W.; Vadas, Sharon L.; Wang, Yun; Weinberg, Erick J.

1989-01-01

435

Negative birefringent polyimide films  

NASA Technical Reports Server (NTRS)

A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

Harris, Frank W. (Inventor); Cheng, Stephen Z. D. (Inventor)

1994-01-01

436

Kriging without negative weights  

SciTech Connect

Under a constant drift, the linear kriging estimator is considered as a weighted average of n available sample values. Kriging weights are determined such that the estimator is unbiased and optimal. To meet these requirements, negative kriging weights are sometimes found. Use of negative weights can produce negative block grades, which makes no practical sense. In some applications, all kriging weights may be required to be nonnegative. In this paper, a derivation of a set of nonlinear equations with the nonnegative constraint is presented. A numerical algorithm also is developed for the solution of the new set of kriging equations.

Szidarovszky, F.; Baafi, E.Y.; Kim, Y.C.

1987-08-01

437

Introduction to Negative Numbers  

NSDL National Science Digital Library

This lesson plan based on a Cyberchase activity, first addresses a common misconception: starting measurement from 1 instead of 0. Then, it introduces negative numbers by extending a number line beyond 0 in the negative (left) direction. It is motivated by the Cyber Squadâs mission to find the captured Cyberchase Council on a particular floor of a tall building as seen in two quicktime videos: âImportance of the Origin" and "Inventing Negative Numbers" (each are cataloged separately). In addition to the learning activity, other support materials are included: handouts, assessments and answer keys.

Wnet.org

2006-01-01

438

Negative electrode composition  

DOEpatents

A secondary electrochemical cell and a negative electrode composition for use therewith comprising a positive electrode containing an active material of a chalcogen or a transiton metal chalcogenide, a negative electrode containing a lithium-aluminum alloy and an amount of a ternary alloy sufficient to provide at least about 5 percent overcharge capacity relative to a negative electrode solely of the lithium-aluminum alloy, the ternary alloy comprising lithium, aluminum, and iron or cobalt, and an electrolyte containing lithium ions in contact with both of the positive and the negative electrodes. The ternary alloy is present in the electrode in the range of from about 5 percent to about 50 percent by weight of the electrode composition and may include lithium-aluminum-nickel alloy in combination with either the ternary iron or cobalt alloys. A plurality of series connected cells having overcharge capacity can be equalized on the discharge side without expensive electrical equipment.

Kaun, Thomas D. (New Lenox, IL); Chilenskas, Albert A. (Western Springs, IL)

1982-01-01

439

Improved Negative Ion Source.  

National Technical Information Service (NTIS)

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cyclo...

J. E. Delmore

1984-01-01

440

ON THE LOW FALSE POSITIVE PROBABILITIES OF KEPLER PLANET CANDIDATES  

SciTech Connect

We present a framework to conservatively estimate the probability that any particular planet-like transit signal observed by the Kepler mission is in fact a planet, prior to any ground-based follow-up efforts. We use Monte Carlo methods based on stellar population synthesis and Galactic structure models, and report false positive probabilities (FPPs) for every Kepler Object of Interest, assuming a 20% intrinsic occurrence rate of close-in planets in the radius range 0.5 R{sub +} < R{sub p} < 20 R{sub +}. Nearly 90% of the 1235 candidates have FPP <10%, and over half have FPP <5%. This probability varies with the magnitude and Galactic latitude of the target star, and with the depth of the transit signal-deeper signals generally have higher FPPs than shallower signals. We establish that a single deep high-resolution image will be an effective follow-up tool for the shallowest (Earth-sized) transits, providing the quickest route toward probabilistically validating the smallest candidates by potentially decreasing the FPP of an Earth-sized transit around a faint star from >10% to <1%. Since Kepler has detected many more planetary signals than can be positively confirmed with ground-based follow-up efforts in the near term, these calculations will be crucial to using the ensemble of Kepler data to determine population characteristics of planetary systems. We also describe how our analysis complements the Kepler team's more detailed BLENDER false positive analysis for planet validation.

Morton, Timothy D.; Johnson, John Asher, E-mail: tdm@astro.caltech.edu, E-mail: johnjohn@astro.caltech.edu [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)

2011-09-10

441

Cobbles in Troughs Between Meridiani Ripples (False Color)  

NASA Technical Reports Server (NTRS)

As NASA's Mars Exploration Rover Opportunity continues to traverse from 'Erebus Crater' toward 'Victoria Crater,' the rover navigates along exposures of bedrock between large, wind-blown ripples. Along the way, scientists have been studying fields of cobbles that sometimes appear on trough floors between ripples. They have also been studying the banding patterns seen in large ripples.

This view, obtained by Opportunity's panoramic camera on the rover's 802nd Martian day (sol) of exploration (April 27, 2006), is a mosaic spanning about 30 degrees. It shows a field of cobbles nestled among wind-driven ripples that are about 20 centimeters (8 inches) high.

The origin of cobble fields like this one is unkn