43 research outputs found

    Individual differences in first- and second-order temporal judgment

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    The ability of subjects to identify and reproduce brief temporal intervals is influenced by many factors whether they be stimulus-based, task-based or subject-based. The current study examines the role individual differences play in subsecond and suprasecond timing judgments, using the schizoptypy personality scale as a test- case approach for quantifying a broad range of individual differences. In two experiments, 129 (Experiment 1) and 141 (Experiment 2) subjects completed the O-LIFE personality questionnaire prior to performing a modified temporal-bisect ion task. In the bisection task, subjects responded to two identical instantiations of a luminance grating presented in a 4deg window, 4deg above fixation for 1.5 s Experiment 1) or 3 s (Experiment 2). Subjects initiated presentation with a button- press, and released the button when they considered the stimulus to be half-way through (750/1500 ms). Subjects were then asked to indicate their ‘most accurate estimate’ of the two intervals. In this way we measure both performance on the task (a first-order measure) and the subjects’ knowledge of their performance (a second-order measure). In Experiment 1 the effect of grating-drift and feedback on performance was also examined. Experiment 2 focused on the static/no-feedback condition. For the group data, Experiment 1 showed a significant effect of presentation order in the baseline condition (no feedback), which disappeared when feedback was provided. Moving the stimulus had no effect on perceived duration. Experiment 2 showed no effect of stimulus presentation order. This elimination of the subsecond order-effect was at the expense of accuracy, as the mid-point of the suprasecond interval was generally underestimated. Response precision increased as a proportion of total duration, reducing the variance below that predicted by Weber’s law. This result is consistent with a breakdown of the scalar properties of time perception in the early suprasecond range. All subjects showed good insight into their own performance, though that insight did not necessarily correlate with the veridical bisection point. In terms of personality, we found evidence of significant differences in performance along the Unusual Experiences subscale, of most theoretical interest here, in the subsecond condition only. There was also significant correlation with Impulsive Nonconformity and Cognitive Disorganisation in the sub- and suprasecond conditions, respectively. Overall, these data support a partial dissocation of timing mechanisms at very short and slightly longer intervals. Further, these results suggest that perception is not the only critical mitigator of confidence in temporal experience, since individuals can effectively compensate for differences in perception at the level of metacognition in early suprasecond time. Though there are individual differences in performance, these are perhaps less than expected from previous reports and indicate an effective timing mechanism dealing with brief durations independent of the influence of significant personality trait differences

    PrÀvalenz von HerzgerÀuschen, Aorten- und Pulmonalstenosen bei Zuchtuntersuchungen von Boxern in der Schweiz

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    Boxer are predisposed to subaortic (SAS) and pulmonic stenosis (PS). To decrease the prevalence, pre-breeding cardiologic exams were performed in the last years. In our study the results of 309 pre-breeding exams of boxers presented between 1999 and 2008 were evaluated retrospectively. The overall prevalence of heart murmurs was 26.5 %. A SAS was diagnosed in 25 (8.1 %) and a PS in 10 (3.3 %) dogs. A combination of both defects was found in 7 (2.3 %) Boxers. Animals with a heart murmur of at least grade 3/6 had a significantly higher peak aortic flow velocity (VmaxAo) than animals without or only soft heart murmurs. Over the study period both the frequency of heart murmurs and diagnosis of SAS and PS decreased

    Preliminary results of the analysis of liver biopsies for the diagnosis of iron storage diesease in captive lemurs

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    [Prevalence of heart murmurs, aortic and pulmonic stenosis in boxers presented for pre-breeding exams in Switzerland]

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    Boxer are predisposed to subaortic (SAS) and pulmonic stenosis (PS). To decrease the prevalence, pre-breeding cardiologic exams were performed in the last years. In our study the results of 309 pre-breeding exams of boxers presented between 1999 and 2008 were evaluated retrospectively. The overall prevalence of heart murmurs was 26.5 %. A SAS was diagnosed in 25 (8.1 %) and a PS in 10 (3.3 %) dogs. A combination of both defects was found in 7 (2.3 %) Boxers. Animals with a heart murmur of at least grade 3/6 had a significantly higher peak aortic flow velocity (VmaxAo) than animals without or only soft heart murmurs. Over the study period both the frequency of heart murmurs and diagnosis of SAS and PS decreased

    Urethral duplication and chromosomal translocation in a Swiss braunvieh heifer

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    As it was urinating, a six-month-old Swiss braunvieh heifer produced a second stream of urine from a fistula that opened on the ventrolateral margin of the left vulval lip. A catheter was introduced into this opening and passed easily into the bladder. Urethrography showed that the fistula joined the urethra in the mid-pelvic region and that a single canal originated from the bladder. Endoscopy confirmed this finding and also revealed a duplication of the vaginal portion of the cervix, a division of the cranial vagina by a septum and a fibrous band in the region of the hymenal ring. Cytogenetic examination revealed reciprocal translocation between chromosomes 20q23 and 22q23. A diagnosis of urethra duplex, duplication of the vaginal portion of the cervix and reciprocal autosomal translocation between chromosomes 20 and 22 was made on the basis of these findings

    Atmospheric science: Glaciers between two drivers

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    It is assumed that the monsoon is the dominant influence on Himalayan glaciers. However, a study now investigates the importance of the mid-latitude Westerlies and shows that glacier changes can be triggered from afar

    Primary ciliary dyskinesia with situs inversus totalis, hydrocephalus internus and cardiac malformations in a dog.

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    A nine-month-old golden retriever bitch was presented with exercise intolerance and recurrent nasal discharge. Based on clinical, radiographic and ultrasonographic examination, a diagnosis of rhinitis, situs inversus totalis and tricuspid valve insufficiency was established. The results of video- and electron microscopy studies of the respiratory epithelium were compatible with primary ciliary dyskinesia (PCD). However, no evidence of a primary ultrastructural defect of the cilia was found. The dog was euthanased because of the poor prognosis. At necropsy, a hydrocephalus internus and a subaortic stenosis were additionally diagnosed. PCD, in combination with situs inversus, has been previously reported in golden retrievers, but without a concomitant hydrocephalus internus. Furthermore, concomitant occurrence of internal cardiac malformation and PCD has not previously been reported in the dog

    [Br-76]bromodeoxyuridine PET in tumor-bearing animals

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    5-bromodeoxyuridine (BUdR) provides in vitro measures of tumor cell proliferation. We used positron emission tomography to study tissue and plasma kinetics of [Br-76]BUdR in tumor-bearing animals. In order to account for the slow washout of the major plasma metabolite, [Br-76]bromide, a mathematical correction for the distribution volume of [Br-76]bromide was applied. However, following correction specific tumor tracer retention was low or even zero and did not correlate with independent measures of proliferation. The kinetic characteristics of [Br-76]BUdR make this tracer unsuitable for proliferation imaging. (C) 2001 Elsevier Science Inc. All rights reserved
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