215 research outputs found
The Daubert/Kumho Implications of Observer Effects in Forensic Science: Hidden Problems of Expectation and Suggestion
After the Supreme Court's decision in Kumho Tire v. Carmichael and the recent amendment of Federal Rule of Evidence 702, proffers of expert testimony will have to be found reliable for the particular application of the asserted expertise to the "task at hand." That is, expertise which is reliable in some global sense, which might apply to other cases but not to the particular application before the court, does not satisfy the requirements for admission. With that in mind, this article examines the phenomoenon of "observer effects" and the vulnerability of forensic science examinations to such observer effects. Observer effects occur when the results of an examination are distorted by the context and state of the observer, including the observer's expectations and desires. The article reviews the findings and practices of a range of scientific fields concerning such observer effects and their control, with special attention to the relevant research and theory from cognative and social psychology. This literature establishes that in virtually every area of human judgment, such observer effects have a relentless and sometimes dramatic effect on the accuracy of results. The article then examines current forensic science practice in light of that research, concluding that forensic science practice is far behind most scientific fields in controlling for such effects, leaving the reliability and accuracy of many forensic science results in doubt. The article then suggests practical ways in which forensic science practice can be changed to reduce such problems, such as the adoption of blind testing regimes. Finally, the article analyzes the current state of the law under Kumho Tire and Rule 702, concluding that the results of forensic science examinations are in danger of being excluded if their reliability continues to be undermined by the failure to control observer effects.Psycholog
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Bayes Wars Redivivus - An Exchange
An electronic exchange among 10 evidence scholars that began with a discussion of the restyled Federal Rules and grew into a significant restatement of debates in evidentiary scholarship over the last 50 years, touching on relevance, probative value, inference, Bayesianism and the foundations of evidence, with an introduction by Michael Risinger
Interictal cerebral metabolism in partial epilepsies of neocortical origin
We performed interietal [18F]fluorodeoxyglucose positron emission tomography (FDG PET) in 24 patients with partial epilepsy of neocortical origin. Two-thirds of patients had regions of hypometabolism. The zone of intracranially recorded electrographic ictal onset was always located in a region of hypometabolism, in those with hypometabolism. Hypometabolic regions in partial epilepsies of neocortical origin were usually associated with structural imaging abnormalities. Regional hypometabolism occasionally occurred without localizing ictal scalp EEG and cerebral magnetic resonance imaging findings, however. FDG PET may be useful in directing placement of intracranial electrodes for presurgical evaluation of refractory neocortical seizures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29049/1/0000082.pd
Ictal Behaviors During Nonepileptic Seizures Differ in Patients with Temporal Lobe Interictal Epileptiform EEG Activity and Patients Without Interictal Epileptiform EEG Abnormalities
Purpose: Ictal behaviors during psychogenic non-epileptic seizures (NES) vary considerably among individuals, and can closely resemble common semiologies of epileptic seizures (ES). We tested the hypothesis that behaviors during NES in patients who have temporal spikes would more closely resemble behaviors during ES in patients with temporal lobe epilepsy than would behaviors during NES in patients who do not have EEG spikes. Methods: We identified 20 patients who had interictal temporal EEG spikes and EEG-video recorded NES (Study Group), 133 patients with temporal EEG spikes and recorded ES, without NES (Epileptic Group), and 24 patients with recorded NES and no epileptiform EEG abnormalities, without ES (Nonepileptic Group). Results: The hypothesis was supported with regard to ictal motor behaviors. Motionless staring or complex automatisms occurred mainly during NES in the Study Group and during ES in the Epileptic Group. In contrast, convulsive movements or flaccid falls were most common during NES in the Nonepileptic Group. Duration of unresponsiveness was longer, and there were fewer postictal states in NES both in the Study and Non-epileptic Groups. Unresponsiveness was briefer and postictal states were more consistent in ES in the Epileptic Group, however. Conclusions: Stereotyped motor activities during NES presumably represent learned behaviors. Processes underlying acquisition of ictal behaviors of NES probably differ in patients with interictal epileptiform EEG abnormalities compared to those without. Prior experiences and temporal lobe dysfunctions that are associated with epilepsy, and psychological characteristics that are unrelated to interictal epileptic dysfunctions, may determine ictal behaviors during NES.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65913/1/j.1528-1157.1998.tb01355.x.pd
A Pair of Dopamine Neurons Target the D1-Like Dopamine Receptor DopR in the Central Complex to Promote Ethanol-Stimulated Locomotion in Drosophila
Dopamine is a mediator of the stimulant properties of drugs of abuse, including ethanol, in mammals and in the fruit fly Drosophila. The neural substrates for the stimulant actions of ethanol in flies are not known. We show that a subset of dopamine neurons and their targets, through the action of the D1-like dopamine receptor DopR, promote locomotor activation in response to acute ethanol exposure. A bilateral pair of dopaminergic neurons in the fly brain mediates the enhanced locomotor activity induced by ethanol exposure, and promotes locomotion when directly activated. These neurons project to the central complex ellipsoid body, a structure implicated in regulating motor behaviors. Ellipsoid body neurons are required for ethanol-induced locomotor activity and they express DopR. Elimination of DopR blunts the locomotor activating effects of ethanol, and this behavior can be restored by selective expression of DopR in the ellipsoid body. These data tie the activity of defined dopamine neurons to D1-like DopR-expressing neurons to form a neural circuit that governs acute responding to ethanol
Diagnostic and prognostic impact of serum HE4 detection in endometrial carcinoma patients
Background:To date, no good marker for screening or disease monitoring of endometrial cancer (EC) is available. The aims of this study were to investigate HE4 gene, protein expression and serum HE4 (sHE4) levels in a panel of ECs and normal endometria (NEs) and to correlate sHE4 with patient clinicopathological characteristics and prognosis.Methods:Using quantitative real-time PCR we tested 46 ECs and 20 NEs for HE4 gene expression. Protein expression was analysed by immunohistochemistry on tissue microarrays in 153 ECs and 33 NEs. Pre-operative serum samples from 138 EC and 76 NE patients were analysed with HE4-EIA assay. Association between sHE4 and patient clinicopathological characteristics or outcome was evaluated.Results:Protein and HE4 gene were significantly upregulated in EC tissues and sera, compared with controls. High sHE4 levels were significantly associated with worse EC clinical characteristics. By univariate survival analysis, high sHE4 levels significantly correlated with decreased overall survival, progression-free survival and disease-free survival, retaining their independent prognostic value on the poorly differentiated EC cohort.Conclusion:We demonstrate, for the first time, that high sHE4 levels correlates with an aggressive EC phenotype and may constitute an independent prognostic factor for poorly differentiated-ECs. Determination of sHE4 could be clinically useful in identifying high-risk EC patients for a more aggressive adjuvant therapy.British Journal of Cancer advance online publication, 5 April 2011; doi:10.1038/bjc.2011.109 www.bjcancer.com
Phosphorylation of Syntaxin‐1a by casein kinase 2α (CK2α) regulates presynaptic vesicle exocytosis from the reserve pool
The t-soluble NSF-attachment protein receptor protein Syntaxin-1a (Stx-1a) is abundantly expressed at pre-synaptic terminals where it plays a critical role in the exocytosis of neurotransmitter-containing synaptic vesicles. Stx-1a is phosphorylated by Casein kinase 2α (CK2α) at Ser14, which has been proposed to regulate the interaction of Stx-1a and Munc-18 to control of synaptic vesicle priming. However, the role of CK2α in synaptic vesicle dynamics remains unclear. Here, we show that CK2α over-expression reduces evoked synaptic vesicle release. Furthermore, shRNA-mediated knockdown of CK2α in primary hippocampal neurons strongly enhanced vesicle exocytosis from the reserve pool, with no effect on the readily releasable pool of primed vesicles. In neurons in which endogenous Stx-1a was knocked down and replaced with a CK2α phosphorylation-deficient mutant, Stx-1a(D17A), vesicle exocytosis was also increased. These results reveal a previously unsuspected role of CK2α phosphorylation in specifically regulating the reserve synaptic vesicle pool, without changing the kinetics of release from the readily releasable pool
The consequences of understanding expert probability reporting as a decision
In this paper we reiterate that the personalist interpretation of probability is inevitable and as least as informed as any other allegedly more ‘objective’ definition of probability. We also argue that the problem faced by forensic scientists, the reporting on imperfect personal knowledge, in terms of probabilities, can be reconstructed as a decision problem. Tackling this problem through a rigorous decision theoretic analysis provides further argument in support of the view that optimal probability reporting is in terms of single numbers, not intervals
E-Cadherin Destabilization Accounts for the Pathogenicity of Missense Mutations in Hereditary Diffuse Gastric Cancer
E-cadherin is critical for the maintenance of tissue architecture due to its role in cell-cell adhesion. E-cadherin mutations are the genetic cause of Hereditary Diffuse Gastric Cancer (HDGC) and missense mutations represent a clinical burden, due to the uncertainty of their pathogenic role. In vitro and in vivo, most mutations lead to loss-of-function, although the causal factor is unknown for the majority. We hypothesized that destabilization could account for the pathogenicity of E-cadherin missense mutations in HDGC, and tested our hypothesis using in silico and in vitro tools. FoldX algorithm was used to calculate the impact of each mutation in E-cadherin native-state stability, and the analysis was complemented with evolutionary conservation, by SIFT. Interestingly, HDGC patients harbouring germline E-cadherin destabilizing mutants present a younger age at diagnosis or death, suggesting that the loss of native-state stability of E-cadherin accounts for the disease phenotype. To elucidate the biological relevance of E-cadherin destabilization in HDGC, we investigated a group of newly identified HDGC-associated mutations (E185V, S232C and L583R), of which L583R is predicted to be destabilizing. We show that this mutation is not functional in vitro, exhibits shorter half-life and is unable to mature, due to premature proteasome-dependent degradation, a phenotype reverted by stabilization with the artificial mutation L583I (structurally tolerated). Herein we report E-cadherin structural models suitable to predict the impact of the majority of cancer-associated missense mutations and we show that E-cadherin destabilization leads to loss-of-function in vitro and increased pathogenicity in vivo
Tetraspanin CD151 is a novel prognostic marker in poor outcome endometrial cancer
BACKGROUND: Type II cancers account for 10% of endometrial cancers but 50% of recurrence. Response rates to chemotherapy at recurrence are poor and better prognostic markers are needed to guide therapy. CD151 is a small transmembrane protein that regulates cell migration and facilitates cancer metastasis. High CD151 expression confers poor prognosis in breast, pancreatic and colorectal cancer. The prognostic significance of tetraspanin CD151 expression in poor outcome endometrial cancers was evaluated, along with oestrogen receptor (ER), progesterone receptor (PR), p53, human epidermal growth factor receptor -2 (HER-2), and CD 151 staining compared with α6β1, α3β1 integrins, and E-cadherin. METHODS: Tissue microarray constructed from 156 poor outcome endometrial cancers, tested with immunohistochemistry and staining correlated with clinicopathological data were used. A total of 131 data sets were complete for analysis. RESULTS: Expression of CD151 was significantly higher in uterine papillary serous and clear cell carcinoma than in grade 3 endometrioid carcinoma, sarcoma or carcinosarcoma (P<0.001). In univariate analysis, age, stage, histology type and CD151 were significant for both recurrence free (RFS) and disease specific survival (DSS). In multivariate analyses, CD151 was significant for RFS and DSS (P=0.036 and 0.033, respectively) in triple negative (ER, PR and HER-2 negative) tumours (88/131). The HER-2, p53, ER and PR were not prognostic for survival. There was strong concordance of CD151 with E-cadherin (98%), but not with α6β1 (35%), α3β1 staining (60%). CONCLUSION: The CD151 is a novel marker in type 2 cancers that can guide therapeutic decisions. CD151 may have an important role in tumourigenesis in some histology types
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