3,303 research outputs found
Ageing makes us dyslexic
Background: The effects of typical ageing on spoken language are well known: word production is disproportionately affected while syntactic processing is relatively well preserved. Little is known, however, about how ageing affects reading.Aims: What effect does ageing have on written language processing? In particular, how does it affect our ability to read words? How does it affect phonological awareness (our ability to manipulate the sounds of our language)?Methods & Procedures: We tested 14 people with Parkinson's disease (PD), 14 typically ageing adults (TAA), and 14 healthy younger adults on a range of background neuropsychological tests and tests of phonological awareness. We then carried out an oral naming experiment where we manipulated consistency, and a nonword repetition task where we manipulated the word-likeness of the nonwords.Outcomes & Results: We find that normal ageing causes individuals to become mildly phonologically dyslexic in that people have difficulty pronouncing nonwords. People with Parkinson's disease perform particularly poorly on language tasks involving oral naming and metalinguistic processing. We also find that ageing causes difficulty in repeating nonwords. We show that these problems are associated with a more general difficulty in processing phonological information, supporting the idea that language difficulties, including poorer reading in older age, can result from a general phonological deficit.Conclusions: We suggest that neurally this age-induced dyslexia is associated with frontal deterioration (and perhaps deterioration in other regions) and cognitively to the loss of executive processes that enable us to manipulate spoken and written language. We discuss implications for therapy and treatment
Training Effectiveness: An Empirical Examination of Factors Outside the Training Context
The influence of factors beyond the immediate training context only recently has been considered in research on training effectiveness. The purpose of this study was to examine the impact of the work environment on pretraining motivation, and the subsequent impact of pretraining motivation on two training effectiveness criteria: knowledge acquisition and training reactions. Using data collected from two foodservice safety training programs, the results from correlation and regression analyses showed that trainee perceptions about managerial support for training, as well as perceptions about the availability of equipment necessary to utilize training, had a direct influence on pretraining motivation. The results also showed that pretraining motivation was directly related to knowledge acquisition and positive reactions to training
Opioids depress cortical centers responsible for the volitional control of respiration
Respiratory depression limits provision of safe opioid analgesia and is the main cause of death in drug addicts. Although opioids are known to inhibit brainstem respiratory activity, their effects on cortical areas that mediate respiration are less well understood. Here, functional magnetic resonance imaging was used to examine how brainstem and cortical activity related to a short breath hold is modulated by the opioid remifentanil. We hypothesized that remifentanil would differentially depress brain areas that mediate sensory-affective components of respiration over those that mediate volitional motor control. Quantitative measures of cerebral blood flow were used to control for hypercapnia-induced changes in blood oxygen level-dependent (BOLD) signal. Awareness of respiration, reflected by an urge-to-breathe score, was profoundly reduced with remifentanil. Urge to breathe was associated with activity in the bilateral insula, frontal operculum, and secondary somatosensory cortex. Localized remifentanil-induced decreases in breath hold-related activity were observed in the left anterior insula and operculum. We also observed remifentanil-induced decreases in the BOLD response to breath holding in the left dorsolateral prefrontal cortex, anterior cingulate, the cerebellum, and periaqueductal gray, brain areas that mediate task performance. Activity in areas mediating motor control (putamen, motor cortex) and sensory-motor integration (supramarginal gyrus) were unaffected by remifentanil. Breath hold-related activity was observed in the medulla. These findings highlight the importance of higher cortical centers in providing contextual awareness of respiration that leads to appropriate modulation of respiratory control. Opioids have profound effects on the cortical centers that control breathing, which potentiates their actions in the brainstem
Dobutamine stress MRI in pulmonary hypertension: relationships between stress pulmonary artery relative area change, RV performance, and 10-year survival
In pulmonary hypertension (PH), right ventricular (RV) performance determines survival. Pulmonary artery (PA) stiffening is an important biomechanical event in PH and also predicts survival based on the PA relative area change (RAC) measured at rest using magnetic resonance imaging (MRI). In this exploratory study, we sought to generate novel hypotheses regarding the influence of stress RAC on PH prognosis and the interaction between PA stiffening, RV performance and survival. Fifteen PH patients underwent dobutamine stress-MRI (ds-MRI) and right heart catheterization. RACREST, RACSTRESS, and ΔRAC (RAC STRESS – RAC REST) were correlated against resting invasive hemodynamics and ds-MRI data regarding RV performance and RV-PA coupling efficiency (n’vv [RV stroke volume/RV end-systolic volume]). The impact of RAC, RV data, and n’vv on ten-year survival were determined using Kaplan–Meier analysis. PH patients with a low ΔRAC (<−2.6%) had a worse long-term survival (log-rank P = 0.045, HR for death = 4.46 [95% CI = 1.08–24.5]) than those with ΔRAC ≥ −2.6%. Given the small sample, these data should be interpreted with caution; however, low ΔRAC was associated with an increase in stress diastolic PA area indicating proximal PA stiffening. Associations of borderline significance were observed between low RACSTRESS and low n’vvSTRESS, Δη’VV, and ΔRVEF. Further studies are required to validate the potential prognostic impact of ΔRAC and the biomechanics potentially connecting low ΔRAC to shorter survival. Such studies may facilitate development of novel PH therapies targeted to the proximal PA
Research Notes : United States : Screening progeny of mutagen-treated soybean seeds for nonfluorescent root mutants
Delannay and Palmer (1982) reported four nonallelic mutants, three re-cessive and one dominant, that controlled root fluorescence in soybean. It was during this investigation that we became interested in looking for mutagen-induced nonfluorescent mutants. In the fall of 1980, we wrote to various soybean researchers who were engaged in mutagenesis programs
Right to Serve, Right to Lead: Lives and Legacies of the USCT
This is a catalog for an exhibit that follows the evolution of African-American participation in the Civil War, from slaves, to contrabands, to soldiers of the United States Colored Troops (USCT), as well as the lives of black veterans beyond the war, and their ultimate military and social legacy. Using a variety of period items, it creates a narrative that stretches from the Antebellum Period to the current day. In doing so, the exhibit shows how black sacrifice on the battlefield redefined the war\u27s purpose throughout the divided nation, how Jim Crowe suppressed the memory of black participation after Reconstruction, and how the illustrious African-American military tradition left by the USCT endures to this day in their modern heirs
Biodiverse Forage Mixtures for Bees and Beef Cattle
Introduction: Beef cattle performance in the southeastern US is limited by tall fescue (TF) toxicosis. Native warm season grasses (NWSGs) can provide alternative forage for cattle and reduce TF toxicosis. Pollinator populations, especially bees, also have been declining across North America. Introducing native wildflowers into tall fescue grasslands might improve pollinator populations. An ongoing grazing experiment in central Virginia USA is testing the feasibility of integrating wildflowers and native grasses as a way to generate ecosystem services.
Objectives: This study sought to determine whether including native grasses and wildflowers in tall fescue pasture systems could improve beef heifer performance.
Methods: The grazing experiment consists of three treatments replicated 4x: 1) tall fescue pasture diversified with native warm-season grasses and wildflowers (WF), 2) tall fescue pasture with portable shade structure to reduce heifer body temperature, and 3) a tall fescue control. All paddocks (1-ha ea.) were planted to an endophyte-infected tall fescue base. Four heifers were set stocked in each paddock. Average daily gain (ADG), body temperature, forage mass, and botanical composition were measured during 2021 and 2022 growing seasons.
Results and Discussion: Seasonal ADG did not significantly differ among treatments in 2021 and averaged 0.49 kg head-1 d-1. In 2022, seasonal ADG for the wildflower paddocks was 0.45 kg head-1 d-1, double the ADG of the control. Body temperature data suggest that shade reduced heifer body temperature over unshaded heifers. Forage mass was not significantly different at most timepoints, and gradually increased then declined over the course of both seasons. Tall fescue stands had few weedy species, native warm season grass stands had some weed competition, and the wildflower stands were so weedy that they required replanting.
Conclusions: Integration of native warm-season grasses into tall fescue pastures improved beef cattle performance in summer. These gains occurred even when \u3e10% of pasture area was devoted to non-forage wildflower plantings. We suggest greater diversification of tall fescue pastures generates ecosystem services and can be compatible with robust beef cattle production in this region
Reciprocal influence model of working alliance and therapeutic outcome over individual therapy course.
Development and Validation of Spatially Explicit Habitat Models for Cavity-nesting Birds in Fishlake National Forest, Utah
The ability of USDA Forest Service Forest Inventory and analysis (FIA) generated spatial products to increase the predictive accuracy of spatially explicit, macroscale habitat models was examined for nest-site selection by cavity-nesting birds in Fishlake National Forest, Utah. One FIA-derived variable (percent basal area of aspen trees) was significant in the habitat model; however, the incorporation of FIA stand structure information did not increase model accuracy. Cavity-nesting birds respond strongly to nest-tree attributes unable to be modeled spatially for this study. Future modeling efforts should focus on larger taxa (e.g., ungulates) and richness/diversity studies
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