New migraine with visual disturbance after cryoballoon ablation of atrial fibrillation.

We report the case of a 58-year-old woman who developed a headache and visual disturbances after a cryoballoon ablation procedure for atrial fibrillation at our institution. She presented to the emergency department four days post ablation and was admitted the hospital for overnight observation. Serial neurological examinations and neuroimaging were unremarkable for stroke or transient ischemic attack. The patient had some brief transient visual changes which resolved completely after several days, with no further clinical sequelae. She followed up in the outpatient neuro-ophthalmology clinic and had a normal visual field examination. She was given a diagnosis of new onset migraine with visual aura

Protocol for electrophysiological monitoring of carotid endarterectomies.

Near zero stroke rates can be achieved in carotid endarterectomy (CEA) surgery with selective shunting and electrophysiological neuromonitoring. though false negative rates as high as 40% have been reported. We sought to determine if improved training for interpretation of the monitoring signals can advance the efficacy of selective shunting with electrophysiological monitoring across multiple centers, and determine if other factors could contribute to the differences in reports. Processed and raw beta band (12.5-30 Hz) electroencephalogram (EEG) and median and tibial nerve somatosensory evoked potentials (SSEP) were monitored in 668 CEA cases at six surgical centers. A decrease in amplitude of 50% or more in any EEG or SSEP channel was the criteria for shunting or initiating a neuroprotective protocol. A reduction of 50% or greater in the beta band of the EEG or amplitude of the SSEP was observed in 150 cases. No patient showed signs of a cerebral infarct after surgery. Selective shunting based on EEG and SSEP monitoring can reduce CEA intraoperative stroke rate to a near zero level if trained personnel adopted standardized protocols. We also found that the rapid administration of a protective stroke protocol by attending anesthesiologists was an important aspect of this success rate

Semi-analytical dark matter halos and the Jeans equation

Although N-body studies of dark matter halos show that the density profiles, rho(r), are not simple power-laws, the quantity rho/sigma^3, where sigma(r) is the velocity dispersion, is in fact a featureless power-law over ~3 decades in radius. In the first part of the paper we demonstrate, using the semi-analytic Extended Secondary Infall Model (ESIM), that the nearly scale-free nature of rho/sigma^3 is a robust feature of virialized halos in equilibrium. By examining the processes in common between numerical N-body and semi-analytic approaches, we argue that the scale-free nature of rho/sigma^3 cannot be the result of hierarchical merging, rather it must be an outcome of violent relaxation. The empirical results of the first part of the paper motivate the analytical work of the second part of the paper, where we use rho/sigma^3 proportional to r^{-alpha} as an additional constraint in the isotropic Jeans equation of hydrostatic equilibrium. Our analysis shows that the constrained Jeans equation has different types of solutions, and in particular, it admits a unique ``periodic'' solution with alpha=1.9444. We derive the analytic expression for this density profile, which asymptotes to inner and outer profiles of rho ~ r^{-0.78}, and rho ~ r^{-3.44}, respectively.Comment: 37 pg, 14 fig. Accepted to ApJ: added two figures and extended discussion. Note that an earlier related paper (conference proceedings) astro-ph/0412442 has a mistake in eq.(2.2); the correct version is eq.(5) of the present submissio

Influences of cognitive impairment and healthy ageing on conversational use of verbs, nouns, and pronouns

Alzheimer’s disease (AD) leads to language impairments and higher-level cognitive communication problems. Language impairments experienced by people with AD (pwAD) include lexical-semantic deficits that may result in use of a simplified vocabulary. Reliance on these nonspecific words may contribute to declines in informative content, creating or exacerbating communication problems. Knowledge of this relationship is limited, however, as prior research into language in AD has focused largely on discrete production of words, particularly nouns. This thesis aimed to investigate lexical-semantic changes in discourse by pwAD, with a focus on use of nouns, pronouns, and verbs. The guiding hypothesis was that pwAD would differ from healthy older people in the use of words within and across these parts of speech (POS) in spontaneous speech. Investigation of this hypothesis began with a systematic review (Chapter 2 of thesis) that aimed to synthesise findings on verb processing and identify directions for future research on the use of verbs and other POS by pwAD. Database searches were conducted in 2018 and updated in 2021, leading to the identification of 57 studies that reported on verb processing at word level, in individual sentences, and in discourse. At word level, pwAD were impaired in comprehending and producing both verbs and nouns compared to controls, with greater impairments for verbs than nouns. Effects of frequency and age of acquisition (AoA) were present for pwAD on word production tasks, suggesting that learning history may factor into language changes in AD. On tasks assessing comprehension of individual sentences, pwAD had difficulty with sentences that included multiple verbs or verbs with reversible thematic roles. Few studies were identified that reported on sentence production or discourse comprehension. Discourse production by pwAD was marked by the use of similar or higher numbers of verbs than controls, along with fewer nouns and more pronouns. pwAD relied on simplified language, including high-frequency words such as light verbs (e.g., be), and were found to use a narrower range of words than controls. Holistically, the discourse produced by pwAD was marked by declines in total output and propositional content. It was also observed that, in some studies, a lack of information on performance by controls limited conclusions that could be drawn on performance by pwAD. Two subsequent corpus analyses further investigated possibilities that declines in informative content in spontaneous speech by pwAD may relate to changes in word use by POS or to effects of learning history. These studies also considered the need for thorough reporting on language changes in healthy ageing to create a baseline for interpretation of changes in AD. The first of these studies (Chapter 3 of thesis) analysed conversation samples of a standardised length produced by 12 pwAD and 12 cognitively healthy, age-matched controls for the Carolinas Conversations Collection. Measures included noun, pronoun and verb counts and ratios, lexical diversity, copula use, and frequencies and ages of acquisition (AoA) of nouns and verbs produced. pwAD used fewer nouns and a narrower range of words than controls. Findings also suggested use of more pronouns and a narrower range of nouns. Age affected noun frequencies differently within each group. With age, pwAD were found to produce nouns of lower frequencies, possibly relating to the aggressive course of early-onset AD. Meanwhile, healthy controls ranging in age from 71 to 101 produced nouns of higher frequencies with age. pwAD were found to use nouns of higher AoA than controls, possibly due to group differences in noun token counts. Verb use differed little by group. Together, findings from that study suggested that both healthy ageing and cognitive impairment—declines beyond those seen in healthy ageing—may lead to changes in word use, particularly in the use of nouns. Changes differed by group, with healthily ageing controls using nouns of higher frequencies with age, while pwAD used fewer nouns and more pronouns. However, both types of change might result in the communication of less detail. The second corpus study here (Chapter 4) sought to explore effects of ageing and cognitive ability on word use in a larger group of older participants differentiated not binarily but at a finer level, by global cognitive assessment score. This study analysed quantities of nouns, pronouns, and verbs as well as frequencies and ages of acquisition (AoAs) of nouns and verbs in conversation samples of a standardised length by 241 participants ranging from 64 to 91 years old and from 14 to 30 in Montreal Cognitive Assessment (MoCA) score. Lower MoCA scores were significantly associated with the use of fewer nouns and more pronouns. MoCA scores did not predict verb quantities or noun or verb frequencies or AoAs. These findings on effects of global cognition were in line with those of the previous study. Age did not predict noun quantities, frequencies, or AoAs. It did not predict verb quantities or frequencies but predicted their AoAs. General trends here indicated use of less sophisticated words with age, thus providing some support for findings on effects of ageing from the previous study. In summary, this thesis demonstrated that distinguishing between POS in analyses of spontaneous speech is useful in identifying language changes associated with healthy ageing and cognitive impairment. Findings here indicate that declines in information content in the speech of people experiencing cognitive impairment likely relate to changes in the use of words across POS. Use of pronouns rather than nouns provides less detail about people, places, things, or abstract entities. In contrast to nouns, context may facilitate the production of verbs, which interact more with words around them. Alternatively, it is possible that changes comparable to those for nouns occur among verbs, but that these cannot be captured through traditional POS distinctions. Studies of the use of pro-verbs, which act like pronouns but replace verbs, would help to identify these changes. Findings here suggest that healthy ageing may also lead to lexical-semantic changes that affect information content in spontaneous speech. Unlike people experiencing cognitive impairment, these changes may include use of less sophisticated words within POS. Such findings were inconsistent across the two corpus studies reported here. However, general trends toward use of less sophisticated words as age progresses beyond 64 years old suggest a need for further research on language changes in normal age-related cognitive decline. Findings would facilitate distinctions between language changes suggestive of cognitive impairment and those that may be considered a part of healthy ageing

Bayesian Analysis for Food-Safety Risk Assessment: Evaluation of Dose-Response Functions within WinBUGS

Bayesian methods are becoming increasingly popular in the field of food-safety risk assessment. Risk assessment models often require the integration of a dose-response function over the distribution of all possible doses of a pathogen ingested with a specific food. This requires the evaluation of an integral for every sample for a Markov chain Monte Carlo analysis of a model. While many statistical software packages have functions that allow for the evaluation of the integral, this functionality is lacking in WinBUGS. A probabilistic model, that incorporates a novel numerical integration technique, is presented to facilitate the use of WinBUGS for food-safety risk assessments. The numerical integration technique is described in the context of a typical food-saftey risk assesment, some theoretical results are given, and a snippet of WinBUGS code is provided

Photometric Decomposition of Barred Galaxies

We present a non-parametric method for decomposition of the light of disk galaxies into disk, bulge and bar components. We have developed and tested the method on a sample of 68 disk galaxies for which we have acquired I-band photometry. The separation of disk and bar light relies on the single assumption that the bar is a straight feature with a different ellipticity and position angle from that of the projected disk. We here present the basic method, but recognise that it can be significantly refined. We identify bars in only 47% of the more nearly face-on galaxies in our sample. The fraction of light in the bar has a broad range from 1.3% to 40% of the total galaxy light. If low-luminosity galaxies have more dominant halos, and if halos contribute to bar stability, the luminosity functions of barred and unbarred galaxies should differ markedly; while our sample is small, we find only a slight difference of low significance.Comment: Accepted to appear in AJ, 36 pages, 9 figures, full on-line figures available at http://www.physics.rutgers.edu/~sellwood/Reese.htm

Demographic Factors Affecting the Adoption of Multiple Value-Added Practices by Oklahoma Cow-Calf Producers

The utilization of marketing programs to enhance feeder calf value has been met with modest success in Oklahoma. Value-added programs are continually promoted as avenues for improving cow-calf profitability, but producer adoption of value-added practices lags in spite of research showing the value of these practices. Identifying producer characteristics that increase their likelihood to adopt value-added practices is critical to developing successful outreach efforts. Results from a survey of Oklahoma producers on value-added practice adoption indicate that multiple demographic variables influence a producer’s likelihood of practice adoption. For Extension specialists, results can help in targeting likely adopters and developing methods to overcome barriers to adoption by producers less likely to adopt.Beef producers, value-added practices, practice adoption, negative binomial regression, Poisson regression, Farm Management, Livestock Production/Industries, Q12, Q16,