Cortical And Subcortical Mechanisms For Sound Processing

The auditory cortex is essential for encoding complex and behaviorally relevant sounds. Many questions remain concerning whether and how distinct cortical neuronal subtypes shape and encode both simple and complex sound properties. In chapter 2, we tested how neurons in the auditory cortex encode water-like sounds perceived as natural by human listeners, but that we could precisely parametrize. The stimuli exhibit scale-invariant statistics, specifically temporal modulation within spectral bands scaled with the center frequency of the band. We used chronically implanted tetrodes to record neuronal spiking in rat primary auditory cortex during exposure to our custom stimuli at different rates and cycle-decay constants. We found that, although neurons exhibited selectivity for subsets of stimuli with specific statistics, over the population responses were stable. These results contribute to our understanding of how auditory cortex processes natural sound statistics. In chapter 3, we review studies examining the role of different cortical inhibitory interneurons in shaping sound responses in auditory cortex. We identify the findings that support each other and the mechanisms that remain unexplored. In chapter 4, we tested how direct feedback from auditory cortex to the inferior colliculus modulated sound responses in the inferior colliculus. We optogenetically activated or suppressed cortico-collicular feedback while recording neuronal spiking in the mouse inferior colliculus in response to pure tones and dynamic random chords. We found that feedback modulated sound responses by reducing sound selectivity by decreasing responsiveness to preferred frequencies and increasing responsiveness to less preferred frequencies. Furthermore, we tested the effects of perturbing intra-cortical inhibitory-excitatory networks on sound responses in the inferior colliculus. We optogenetically activated or suppressed parvalbumin-positive (PV) and somatostatin-positive (SOM) interneurons while recording neuronal spiking in mouse auditory cortex and inferior colliculus. We found that modulation of neither PV- nor SOM-interneurons affected sound-evoked responses in the inferior colliculus, despite significant modulation of cortical responses. Our findings imply that cortico-collicular feedback can modulate responses to simple and complex auditory stimuli independently of cortical inhibitory interneurons. These experiments elucidate the role of descending auditory feedback in shaping sound responses. Together these results implicate the importance of the auditory cortex in sound processing

An Item Response Theory analysis of the Verb Subordinates Test

This study presents a psychometric evaluation of the Verb Subordinates Test (VST). The VST assesses lexical competence based on knowledge of troponyms in the verb lexicon. Items are true/false statements with the structure To verbhyponym is a way to verbhypernym. Using Item Response Theory (IRT) analysis, this study examined the difficulty and discriminatory value of different items and difficulty levels of the VST. Statistical analyses showed that the VST is a promising vocabulary assessment measure with high internal consistency and good convergent validity, and that individual VST items, given their frequency range, are differentially informative across the vocabulary trait continuum

Best Practices to Obtain and Maintain PCI Compliance

PCI developed security standards to guide merchants in ensuring sensitive cardholder data is protected. However, data breaches continue, affecting the data of billions of customers and negatively affecting revenue and consumer confidence. Merchants must determine the best approaches to not only obtain, but also maintain PCI compliance. This annotated bibliography considers best practices published from 2004 to 2018 to assist IT departments in implementing security procedures to securely process payment card transactions

Do NSAIDs impede fracture healing?

Nonsteroidal anti-inflammatory drugs (NSAIDs) don't appear to impair clinical fracture healing (strength of recommendation [SOR]: B, inconsistent evidence from a randomized controlled trial [RCT] and retrospective studies). Even though animal studies show delayed healing and nonunion with NSAID use, evidence in humans doesn't merit avoiding NSAIDs in patients with fractures who need the drugs' analgesic and anti-inflammatory benefits

Taking a Leap of Faith: Redefining Teaching and Learning in Higher Education Through Project-Based Learning

This study examines two aspects of teaching with a project-based learning (PBL) model in higher education settings: faculty definitions of PBL and faculty PBL practices, as evidenced by their self-described successes and challenges in implementation. Faculty participants took “a leap of faith” in their teaching practices to redefine what it means to teach and learn using PBL as an instructional methodology. The findings provide insight into how faculty conceptualization of PBL drives implementation; how the PBL approach challenges college-level teachers; and how instructors’ perceptions of their own role in the PBL process impacts how they implement PBL

Can Urethral Retroresistance Pressures Predict Midurethral Sling Outcomes?

OBJECTIVE: To determine whether preoperative urethral resistance pressure (URP) measurements could predict success or failure of a tension-free vaginal tape (TVT) sling. METHODS: Subjects came from a previously published study comparing URP measurements to a validated urinary incontinence symptom survey (UISS). We contacted patients from that study to determine whether they had subsequently undergone TVT surgery. Within that cohort, we determined the “current” (i.e., postoperative) UISS and Sandvik urinary incontinence severity score. Success of a TVT sling in this group was defined in 4 ways: (1) postoperative UISS score \u3c 3, (2) postoperative UISS score \u3c 75% of the preoperative score, (3) postoperative Sandvik score \u3c 6, and (4) postoperative Sandvik score \u3c 2. These definitions of “success” were compared across demographic and treatment variables using the Student’s t test, ANOVA, χ 2 and ROC curves. RESULTS: We contacted 69 women who had in fact received a TVT sling after their participation in the previously published study mentioned above. Among these 69 women, mean preoperative urethral retroresistance pressure values were not predictive of surgical success. CONCLUSION: Preoperative urethral retroresistance pressure measurements did not reliably predict surgical success or failure; therefore, this urodynamic test is of little value to the clinician

Improved Laboratory Transition Probabilities for Neutral Chromium and Re-determination of the Chromium Abundance for the Sun and Three Stars

Branching fraction measurements from Fourier transform spectra in conjunction with published radiative lifetimes are used to determine transition probabilities for 263 lines of neutral chromium. These laboratory values are employed to derive a new photospheric abundance for the Sun: log $\epsilon$(Cr I)$_{\odot}$ = 5.64$\pm$0.01 ($\sigma = 0.07$). These Cr I solar abundances do not exhibit any trends with line strength nor with excitation energy and there were no obvious indications of departures from LTE. In addition, oscillator strengths for singly-ionized chromium recently reported by the FERRUM Project are used to determine: log $\epsilon$(Cr II)$_{\odot}$ = 5.77$\pm$0.03 ($\sigma = 0.13$). Transition probability data are also applied to the spectra of three stars: HD 75732 (metal-rich dwarf), HD 140283 (metal-poor subgiant), and CS 22892-052 (metal-poor giant). In all of the selected stars, Cr I is found to be underabundant with respect to Cr II. The possible causes for this abundance discrepancy and apparent ionization imbalance are discussed.Comment: 44 pages, 6 figure

Abundances of Extremely Metal-Poor Star Candidates

We present chemical abundances for 110 stars identified in objective-prism surveys as candidates to be very metal-poor. The abundances are derived from high S/N, intermediate-resolution spectra obtained with the Keck Observatory Echelle Spectrometer and Imager. An additional 25 stars with well-determined abundances ranging from [Fe/H]$=-1.5$ and -3.2 were observed and the results used to help calibrate our analysis and determine the accuracy of our abundance determinations. Abundances for the program stars were measured for Fe, Mg, Ca, Ti, Cr and Ba with an accuracy of approximately 0.3 dex. 53 of the stars in our sample have [Fe/H]<= -2, 22 have [Fe/H]<= -2.5 and 13 stars have [Fe/H]<= -2.9. Surprisingly, approximately one third of the sample is relatively metal rich with [Fe/H]>-1.5. In addition to identifying a number of extremely metal-poor stars, this study also shows that moderate-resolution spectra obtained with the Keck Echelle Spectrometer and Imager yield relatively accurate abundances for stars as faint as V=14 in modest exposure time (~20 minutes). This capability will prove useful if the so-far elusive stars at [Fe/H]<-4 turn out to be mostly fainter than V=15.Comment: 60 pages, 10 figures, Accepted for publication in the A

Cultivation of Industrial Hemp on and Near Airports: Implications for Wildlife Use and Risk to Aviation Safety

Land-use planning on and near airports should consider possible revenue from land covers, associated maintenance costs, and potential for land covers to attract vertebrate species recognized as hazardous to aviation safety. The U.S. Federal Aviation Administration has expressed interest in recent attention given to industrial hemp (Cannabis sativa L.; hemp) as a revenue-producing land cover that might be cultivated on or near airports. Our purpose was to better understand the potential production value of hemp as well as its possible role in affecting aviation safety if cultivated on or near airports. Our objectives were to: (1) review the literature relative to a historical perspective of hemp cultivation in the United States, projected cultivation practices, and anticipated economic viability, (2) use our review to gather information on vertebrate use of hemp cultivars, and (3) revisit U.S. and international regulations on land covers near airports relative to attraction of species recognized as hazardous to aviation safety. We found, via review of peer-reviewed and gray literature, that hemp holds potential as an emerging crop in the United States, contributing to food, medicine, and biomass-derived products as well as evidence that birds will use, if not depredate, the crop. However, future markets promoting cultivation of hemp remain tentative. Further, there has been no objective quantification of bird and other wildlife use of hemp alone or as a component of a land cover matrix on or near airports and relative to implications for aviation safety. We make recommendations for future research on wildlife use of hemp and metrics necessary to inform aviation safety

Improvement and decline of cognitive function in schizophrenia over one year: a longitudinal investigation using latent growth modelling.

BACKGROUND: Long-term follow-up studies of people with schizophrenia report stability of cognitive performance; less is known about any shorter-term changes in cognitive function. METHODS: This longitudinal study aimed to establish whether there was stability, improvement or decline in memory and executive functions over four assessments undertaken prospectively in one year. Cognitive performance was assessed during randomized controlled trials of first- and second-generation antipsychotic medication. Analyses used a latent growth modeling approach, so that individuals who missed some testing occasions could be included and trajectories of cognitive change explored despite missing data. RESULTS: Over the year there was significant decline in spatial recognition but no change in pattern recognition or motor speed. Improvement was seen in planning and spatial working memory tasks; this may reflect improved strategy use with practice. There were significant individual differences in the initial level of performance on all tasks but not in rate of change; the latter may have been due to sample size limitations. Age, sex, premorbid IQ and drug class allocation explained significant variation in level of performance but could not predict change. Patients randomized to first-generation drugs improved more quickly than other groups on the planning task. CONCLUSION: We conclude that cognitive change is present in schizophrenia but the magnitude of change is small when compared with the large differences in cognitive function that exist between patients. Analyses that retain patients who drop out of longitudinal studies, as well as those who complete testing protocols, are important to our understanding of cognition in schizophrenia.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are