277 research outputs found

    Spatial working memory for locations specified by vision and audition: Testing the amodality hypothesis

    Get PDF
    Spatial working memory can maintain representations from vision, hearing, and touch, representations referred to here as spatial images. The present experiment addressed whether spatial images from vision and hearing that are simultaneously present within working memory retain modality-specific tags or are amodal. Observers were presented with short sequences of targets varying in angular direction, with the targets in a given sequence being all auditory, all visual, or a sequential mixture of the two. On two thirds of the trials, one of the locations was repeated, and observers had to respond as quickly as possible when detecting this repetition. Ancillary detection and localization tasks confirmed that the visual and auditory targets were perceptually comparable. Response latencies in the working memory task showed small but reliable costs in performance on trials involving a sequential mixture of auditory and visual targets, as compared with trials of pure vision or pure audition. These deficits were statistically reliable only for trials on which the modalities of the matching location switched from the penultimate to the final target in the sequence, indicating a switching cost. The switching cost for the pair in immediate succession means that the spatial images representing the target locations retain features of the visual or auditory representations from which they were derived. However, there was no reliable evidence of a performance cost for mixed modalities in the matching pair when the second of the two did not immediately follow the first, suggesting that more enduring spatial images in working memory may be amodal

    Docosanoic acid conjugation to siRNA enables functional and safe delivery to skeletal and cardiac muscles

    Get PDF
    Oligonucleotide therapeutics hold promise for the treatment of muscle- and heart-related diseases. However, oligonucleotide delivery across the continuous endothelium of muscle tissue is challenging. Here, we demonstrate that docosanoic acid (DCA) conjugation of small interfering RNAs (siRNAs) enables efficient (~5% of injected dose), sustainable ( \u3e 1 month), and non-toxic (no cytokine induction at 100 mg/kg) gene silencing in both skeletal and cardiac muscles after systemic injection. When designed to target myostatin (muscle growth regulation gene), siRNAs induced ~55% silencing in various muscle tissues and 80% silencing in heart, translating into a ~50% increase in muscle volume within 1 week. Our study identifies compounds for RNAi-based modulation of gene expression in skeletal and cardiac muscles, paving the way for both functional genomics studies and therapeutic gene modulation in muscle and heart

    Kif15 functions as an active mechanical ratchet

    Get PDF
    Kif15 is a kinesin-12 that contributes critically to bipolar spindle assembly in humans. Here we use force-ramp experiments in an optical trap to probe the mechanics of single Kif15 molecules under hindering or assisting loads and in a variety of nucleotide states. Whilst unloaded Kif15 is established to be highly processive, we find that under hindering loads, Kif15 takes <∼10 steps. As hindering load is increased, Kif15 forestep:backstep ratio decreases exponentially, with stall occurring at 6 pN. By contrast, under assisting loads, Kif15 detaches readily and rapidly, even from its AMPPNP state. Kif15 mechanics thus depend markedly on the loading direction. Kif15 interacts with a binding partner, Tpx2, and we show that Tpx2 locks Kif15 to microtubules under both hindering and assisting loads. Overall, our data predict that Kif15 in the central spindle will act as a mechanical ratchet, supporting spindle extension but resisting spindle compression

    The chemical structure and phosphorothioate content of hydrophobically modified siRNAs impact extrahepatic distribution and efficacy

    Get PDF
    Small interfering RNAs (siRNAs) have revolutionized the treatment of liver diseases. However, robust siRNA delivery to other tissues represents a major technological need. Conjugating lipids (e.g. docosanoic acid, DCA) to siRNA supports extrahepatic delivery, but tissue accumulation and gene silencing efficacy are lower than that achieved in liver by clinical-stage compounds. The chemical structure of conjugated siRNA may significantly impact invivo efficacy, particularly in tissues with lower compound accumulation. Here, we report the first systematic evaluation of the impact of siRNA scaffold-i.e. structure, phosphorothioate (PS) content, linker composition-on DCA-conjugated siRNA delivery and efficacy in vivo. We found that structural asymmetry (e.g. 5- or 2-nt overhang) has no impact on accumulation, but is a principal factor for enhancing activity in extrahepatic tissues. Similarly, linker chemistry (cleavable versus stable) altered activity, but not accumulation. In contrast, increasing PS content enhanced accumulation of asymmetric compounds, but negatively impacted efficacy. Our findings suggest that siRNA tissue accumulation does not fully define efficacy, and that the impact of siRNA chemical structure on activity is driven by intracellular re-distribution and endosomal escape. Fine-tuning siRNA chemical structure for optimal extrahepatic efficacy is a critical next step for the progression of therapeutic RNAi applications beyond liver

    Health disparities within rural communities in the southern region of the United States

    Get PDF
    Intro: Historical studies have shown that health disparities exist between urban and rural communities, however additional disparities are also known to exist within rural communities as well. These include health disparities between races, ethnicities, and socioeconomic statuses, among others. While the disparities between urban and rural communities have been researched and described more extensively, there is a paucity of information available about the disparities that exist within rural communities. Our goal in this research initiative was to characterize the disparities that exist within rural communities by examining the findings of several publications that sought to describe this phenomenon in the past. Method: Protocols evaluated current research studies and identified areas where research was scarce, or nonexistent. Following this evaluation, a literature search was performed using PubMed with the goal of locating and utilizing papers from the last 10 years on the specified topic. Queries were used for pre-identified search terms, which aimed to include the entire range of this topic: ‘rural’, ‘health’, ‘disparities’, ‘minority’, ‘mental’. Inclusion criteria for the literature review included mention of health disparities in rural areas, and that data were from the United States. Exclusion criteria included if data were from a country outside of the United States, or if there was no discussion of rural health. Results of the initial literature search were reviewed manually, and the inclusion and exclusion criteria were applied at that time. Results: The results of this study reveal that nonmetropolitan households were less likely to have digital access which greatly contributed to being uninsured. These results also show that universal policies and procedures geared toward at-risk populations drastically reduced health disparities among these communities. An odds ratio of 1.69 based on a bivariate analysis revealed that rural residents were most likely to exhibit healthcare avoidance behaviors and an odds ratio of 2.24 was indicative in the lack of confidence in personal health care. Furthermore, rural areas were less likely to retain physicians and more likely to have residents with poorer health. Stressful living environments and broader community held beliefs were shown to impact perceptions of mental health and served as a barrier to seeking health. Disparities such as personal income and finances served as estimated predictors of 38.8% of microbial taxa. Such disparities were associated with higher infant mortality rates among black populations and were highest in rural counties. Discussion/Conclusion: This study was done to compile data from different studies and reports to prove that there is a need for equity amongst healthcare in all communities throughout the southern United States region. There is a significant decline in both the access and quality of healthcare in rural communities in this region. Multiple challenges exist due to several factors such as socioeconomic status, digital access, race/ethnicity and many other secondary resources that may need to be acquired in order to access necessary quality healthcare

    The impact of minority physician representation on minority patient health

    Get PDF
    Background: Before the COVID-19 pandemic, the medical profession underwent a physician burnout crisis. Post pandemic, physician burnout transformed into an epidemic that has contributed to the inability of physician supply to meet patient demand in the USA. Recent studies by the American Medical Association predict by 2034, a widespread physician shortage across both primary care and non-primary care specialties (AAMC, 2021). As a result, medical institutions have implemented programs to address this shortage. While this shortage is concerning and needs to be addressed, it isn’t the only shortage at hand. Minorities are deeply underrepresented in the medical field with respect to their proportions in the overall USA population. The ongoing physician shortage further exacerbates the disproportionate number of minority physicians. Furthermore, minority underrepresentation isn’t confined to the profession but is also observed among students in medical schools across the United States. Simultaneously, these same underrepresented minority groups disproportionately experience mortality and disability from disease at higher rates compared to their White counterparts (Smedley, 2001). This study analyzes the inverse relationship between the amount minority physicians present in a community and the prevalence of disease among these same minority populations. It also seeks to understand how representation impacts minority health outcomes. Aim: Involving minority communities in the development and implementation of healthcare policies and programs can lead to better healthcare outcomes for those communities. Methods: A systematic literature review was conducted using PubMed, Scopus, and EBSCOhost databases using keywords [(“MINORITY PHYSICIAN” OR “UNDERREPRESENTED MINORITY PHYSICIANS”)] AND [(“MINORITY PATIENTS” OR “MINORITY PATIENT HEALTH OUTCOMES”) AND (“COMMUNITY-BASED PARTICIPATORY RESEARCH”)] Results: The excess burden of illness in minority populations can be contributed to numerous complex factors, including but not limited to socioeconomic inequality, environmental and occupational exposures, discrimination, health risk factors, and less access to health insurance and healthcare. Practical, actionable strategies to address these disparities should include the engagement of families in leadership roles, provision of comprehensive healthcare, cross-sectoral institutional and community collaborations, and the use of community-based participatory research (CBPR) methods. CBPR has demonstrated promise in enhancing the effectiveness of interventions. However, the challenge remains to understand how and what type of partnerships and participation most effectively enhance the integration of science and practice to eliminate disparities. Discussion: Researchers, community leaders, and healthcare professionals are integral in delivering quality healthcare to minority communities. Researchers must be culturally competent enough to be able to go out into these communities and collect accurate data about these communities. Researchers must find effective strategies and methodologies to gain the trust of the minority community that their research is directly impacting. This can effectively be done by working with local community leaders and community organizations. Local community leaders have the responsibility of voicing the issues and barriers that the community has in accessing quality healthcare. Healthcare professionals have a responsibility to take the research data and work with community leaders to find effective ways to address disparities. In some cases, they may even have to seek funding through government agencies to ensure long-term solutions

    Adductor Strains in Athletes

    Get PDF
    Acute adductor injuries are a common occurrence in sport. The overall incidence of adductor strains across 25 college sports was 1.29 injuries per 1000 exposures, with men's soccer (3.15) and men's hockey (2.47) having the highest incidences. As with most muscle strains there is a high rate of recurrence for adductor strains; 18% in professional soccer and 24% in professional hockey. Effective treatment, with successful return to play, and avoidance of reinjury, can be achieved with a proper understanding of the anatomy, a thorough clinical exam yielding an accurate diagnosis, and an evidence-based treatment approach, including return to play progression

    Sphingosine and dihydrosphingosine as biomarkers for multiple sclerosis identified by metabolomic profiling using coupled UPLC-MS

    Get PDF
    The project aim was to identify differences in the metabolomic profiles in the serum of patients with multiple sclerosis (MS), those with neuropathic pain (NP) and those with both MS and NP compared with controls and to identify potential biomarkers of each disease state. Metabolomic profiling was performed using ultra-high-performance liquid chromatography coupled to mass spectrometry and the data analysis involved parametric methods, principal component analysis, and discriminating filter analysis to determine the differences between disease and control serum samples. Sphingosine and dihydrosphingosine were identified as significant biomarkers
    corecore