The role of the vestibular system in manual target localization

Astronauts experience perceptual and sensory-motor disturbances during spaceflight and immediately after return to the 1-g environment of Earth. During spaceflight, sensory information from the eyes, limbs and vestibular organs is reinterpreted by the central nervous system so that astronauts can produce appropriate body movements in microgravity. Alterations in sensory-motor function may affect eye-head-hand coordination and, thus, the crewmember's ability to manually locate objects in extrapersonal space. Previous reports have demonstrated that crewmembers have difficulty in estimating joint and limb position and in pointing to memorized target positions on orbit and immediately postflight. One set of internal cues that may assist in the manual localization of objects is information from the vestibular system. This system contributes to our sense of the body's position in space by providing information on head position and movement and the orientation of the body with respect to gravity. Research on the vestibular system has concentrated on its role in oculo-motor control. Little is known about the role that vestibular information plays in manual motor control, such as reaching and pointing movements. Since central interpretation of vestibular information is altered in microgravity, it is important to determine its role in this process. This summer, we determined the importance of vestibular information in a subject's ability to point accurately toward a target in extrapersonal space. Subjects were passively rotated across the earth-vertical axis and then asked to point back to a previously-seen target. In the first paradigm, the subjects used both visual and vestibular cues for the pointing response, while, in the second paradigm, subjects used only vestibular information. Subjects were able to point with 85 percent accuracy to a target using vestibular information alone. We infer from this result that vestibular input plays a role in the spatial programming of manual responses

Effect of smoking status on lung function, patient-reported outcomes, and safety among COPD patients treated with glycopyrrolate inhalation powder: pooled analysis of GEM1 and GEM2 studies.

BackgroundSmoking is a major risk factor for COPD and may impact the efficacy of COPD treatments; however, a large proportion of COPD patients continue to smoke following diagnosis.MethodsThis post-hoc analysis of pooled data from the replicate 12-week, placebo-controlled GEM1 and GEM2 studies assessed the impact of smoking status on the efficacy and safety of glycopyrrolate 15.6 μg twice daily vs placebo in patients with moderate-to-severe COPD. Data from 867 patients enrolled in GEM1 and GEM2 were pooled for analysis and grouped by smoking status (57% current smokers, 43% ex-smokers). Forced expiratory volume in 1 s (FEV1) area under the curve from 0 to 12 h, trough FEV1, forced vital capacity, St George's Respiratory Questionnaire (SGRQ) total score, COPD assessment test (CAT) score, transition dyspnea index (TDI) focal score, daily symptom scores, and rescue medication use were assessed in current smokers and ex-smokers. Incidences of adverse events (AEs) and serious AEs (SAEs) were also assessed.ResultsTreatment with glycopyrrolate resulted in significant improvements in all lung function measures, independent of smoking status. In both current and ex-smokers, changes from baseline in trough FEV1 were less marked in patients taking inhaled corticosteroids (ICS) than those not receiving ICS. Changes from baseline in SGRQ total score and rescue medication use were significantly greater with glycopyrrolate compared with placebo, regardless of smoking status. Changes in the CAT score, TDI focal score, and daily symptom scores significantly improved versus placebo, but only in current smokers. Improvements in patient-reported outcomes (PROs) with glycopyrrolate relative to placebo were numerically greater in current smokers than ex-smokers. The incidences of AEs and SAEs were similar regardless of smoking status.ConclusionsIn this post-hoc analysis of GEM1 and GEM2, glycopyrrolate use led to significant improvements in lung function, independent of baseline smoking status; improvements were less marked among patients receiving background ICS, regardless of baseline smoking status. Improvements in PROs were greater with glycopyrrolate than placebo, and the magnitude of changes was numerically greater among current smokers. The safety profile of glycopyrrolate was comparable between current smokers and ex-smokers

Comparing Perceptions of Conflict Mediation Strategies between School Administrators and Non-Administrators

Prior research has explored the impact of conflict mediation practices in schools, regarding students’ perceptions, but existing research has not examined how principals and other school staff members perceive these practices. Given the significant shift away from zero tolerance and towards more restorative practices such as conflict mediation, the current study seeks to examine if school administrators and non-administrators differ in their perceptions of the value of conflict mediation, perceptions of existing conflict mediation skills, and perceptions of the effects of current practices on school climate, as perceptions can influence how information is applied. As these two groups have their own distinct interactions with students, it is hypothesized that they will have differing opinions regarding the instruction and implementation of these conflict mediation techniques. Data were collected from 150 school staff members (108 administrators, 42 non-administrators) from the School District of Philadelphia prior to a professional development training; participants completed a survey assessing perceptions of conflict mediation. School staff were categorized post hoc as administrators or non-administrators based on their self-identification within the survey. A chi-square analysis and three separate multivariate analysis of variance were conducted. Analyses revealed that the two groups did not differ in their experience with conflict mediation, perceptions of the value of conflict mediation, perceptions of their existing mediation skills, or perceptions of the effects of the current practices on school climate. Therefore, school administrators and non-administrators can continue to receive the same training, as long as they maintain similar perceptions regarding these strategies. These findings have implications for current practices, both in terms of designing future mediation trainings, as well as applying these skills within schools.M.S., Psychology -- Drexel University, 201

Population genetic analysis of the Plasmodium falciparum 6-cys protein Pf38 in Papua New Guinea reveals domain-specific balancing selection

<p>Abstract</p> <p>Background</p> <p>The <it>Plasmodium falciparum </it>merozoite surface protein Pf38 is targeted by antibodies of malaria immune adults and has been shown to be under balancing (immune) selection in a Gambian parasite population, indicating potential as a malaria vaccine candidate. This study explores the population genetics of <it>Pf</it>38 in Papua New Guinea, to determine the extent and geographic distribution of diversity and to measure selective pressure along the length of the gene.</p> <p>Methods</p> <p>Using samples collected during community-based cross-sectional surveys in the Mugil and Wosera regions, the <it>Pf38 </it>genes of 59 <it>P. falciparum </it>isolates were amplified and sequenced. These sequences, along with previously sequenced Gambian and laboratory isolates, were then subjected to an array of population genetic analyses, examining polymorphisms, haplotype diversity and balancing selection. In addition to whole-gene analysis, the two 6-cys domains were considered separately, to investigate domain specific polymorphism and selection.</p> <p>Results</p> <p>Nineteen polymorphic sites were identified in the <it>Pf </it>38 gene. Of these, 13 were found in the Gambia, 10 in Mugil and 8 in Wosera. Notably, the majority of common polymorphisms were confined to domain I. Although only moderate levels of nucleotide diversity were observed, the haplotype diversity was high in all populations, suggesting extensive recombination. Analyses of the full-length sequence provided only modest evidence for balancing selection. However, there was a strong contrast between domain I, which showed strong evidence for positive balancing selection, and domain II which was neutral. Analyses of the geographic distribution of Pf38 haplotypes showed that four haplotypes accounted for the majority of sequences found world-wide, but there were many more haplotypes unique to the African than the PNG populations.</p> <p>Conclusion</p> <p>This study confirmed previous findings that <it>Pf38 </it>is a polymorphic gene under balancing selection. However, analysing polymorphism and selection across the length of the gene painted a considerably different picture. Domain I is highly polymorphic and the target of significant balancing selection. In contrast, domain II is relatively conserved and does not show evidence of immune selective pressure. The findings have implications for future population genetic studies on vaccine candidates, showing that the biological context must also be considered as a framework for analysis.</p

Agreeability of ActiGraph and activPal 4™ Measures of Vigorous Activity

Key Words: Accelerometry, activPal 4™, ActiGraph, RPE, HR Introduction: Wearable technologies are consistently used in research to track physical activity and study how it can improve overall health. ActiGraph and activPal are research-grade accelerometers that track activity levels of all intensities in humans. ActivPal has recently improved its technology to measure vigorous activity more accurately to be consistent with the gold standard Actigraph measures. The purpose of this study is to test the agreeability between the vigorous activity measures of the ActiGraph and activPal 4™ devices. Methods: Regular exercisers are being recruited from the KSU Department of Exercise Science and Sports Management to participate. They are fitted with one activPal 4™ on the thigh which will be compared with two ActiGraphs: one worn on the waist and the other worn on the right wrist for three days. Participants record their exercise sessions in an activity diary. Rate of perceived exertion (RPE) and heart rate are also recorded to determine exercise intensity. Exercise is considered vigorous if RPE is 5 or more and if the heart rate is 76% of age-predicted heart rate max or higher. Statistics will include paired t-tests to determine the differences between the means, correlations to determine strength of agreement, and Bland Altman plots for inter-device agreement. Results: Data collection is currently underway, and findings will be presented at the KSU Symposium for Student Scholars. Conclusions: This study will determine the level of agreeability between the ActiGraph and activPal 4™ measures during vigorous activity. It will provide information about whether ActivPal 4 is acceptable to use for measuring vigorous activity in humans

Microtubule dynamics drive enhanced chromatin motion and mobilize telomeres in response to DNA damage

Chromatin exhibits increased mobility on DNA damage, but the biophysical basis for this behavior remains unknown. To explore the mechanisms that drive DNA damage–induced chromosome mobility, we use single-particle tracking of tagged chromosomal loci during interphase in live yeast cells together with polymer models of chromatin chains. Telomeres become mobilized from sites on the nuclear envelope and the pericentromere expands after exposure to DNA-damaging agents. The magnitude of chromatin mobility induced by a single double-strand break requires active microtubule function. These findings reveal how relaxation of external tethers to the nuclear envelope and internal chromatin–chromatin tethers, together with microtubule dynamics, can mobilize the genome in response to DNA damage

Correction: Population Genomics of the Immune Evasion (var) Genes of Plasmodium falciparum

Var genes encode the major surface antigen (PfEMP1) of the blood stages of the human malaria parasite Plasmodium falciparum. Differential expression of up to 60 diverse var genes in each parasite genome underlies immune evasion. We compared the diversity of the DBLalpha domain of var genes sampled from 30 parasite isolates from a malaria endemic area of Papua New Guinea (PNG) and 59 from widespread geographic origins (global). Overall, we obtained over 8,000 quality-controlled DBLalpha sequences. Within our sampling frame, the global population had a total of 895 distinct DBLalpha "types" and negligible overlap among repertoires. This indicated that var gene diversity on a global scale is so immense that many genomes would need to be sequenced to capture its true extent. In contrast, we found a much lower diversity in PNG of 185 DBLalpha types, with an average of approximately 7% overlap among repertoires. While we identify marked geographic structuring, nearly 40% of types identified in PNG were also found in samples from different countries showing a cosmopolitan distribution for much of the diversity. We also present evidence to suggest that recombination plays a key role in maintaining the unprecedented levels of polymorphism found in these immune evasion genes. This population genomic framework provides a cost effective molecular epidemiological tool to rapidly explore the geographic diversity of var genes

Limited antigenic diversity of Plasmodium falciparum apical membrane antigen 1 supports the development of effective multi-allele vaccines

BackgroundPolymorphism in antigens is a common mechanism for immune evasion used by many important pathogens, and presents major challenges in vaccine development. In malaria, many key immune targets and vaccine candidates show substantial polymorphism. However, knowledge on antigenic diversity of key antigens, the impact of polymorphism on potential vaccine escape, and how sequence polymorphism relates to antigenic differences is very limited, yet crucial for vaccine development. Plasmodium falciparum apical membrane antigen 1 (AMA1) is an important target of naturally-acquired antibodies in malaria immunity and a leading vaccine candidate. However, AMA1 has extensive allelic diversity with more than 60 polymorphic amino acid residues and more than 200 haplotypes in a single population. Therefore, AMA1 serves as an excellent model to assess antigenic diversity in malaria vaccine antigens and the feasibility of multi-allele vaccine approaches. While most previous research has focused on sequence diversity and antibody responses in laboratory animals, little has been done on the cross-reactivity of human antibodies.MethodsWe aimed to determine the extent of antigenic diversity of AMA1, defined by reactivity with human antibodies, and to aid the identification of specific alleles for potential inclusion in a multi-allele vaccine. We developed an approach using a multiple-antigen-competition enzyme-linked immunosorbent assay (ELISA) to examine cross-reactivity of naturally-acquired antibodies in Papua New Guinea and Kenya, and related this to differences in AMA1 sequence.ResultsWe found that adults had greater cross-reactivity of antibodies than children, although the patterns of cross-reactivity to alleles were the same. Patterns of antibody cross-reactivity were very similar between populations (Papua New Guinea and Kenya), and over time. Further, our results show that antigenic diversity of AMA1 alleles is surprisingly restricted, despite extensive sequence polymorphism. Our findings suggest that a combination of three different alleles, if selected appropriately, may be sufficient to cover the majority of antigenic diversity in polymorphic AMA1 antigens. Antigenic properties were not strongly related to existing haplotype groupings based on sequence analysis.ConclusionsAntigenic diversity of AMA1 is limited and a vaccine including a small number of alleles might be sufficient for coverage against naturally-circulating strains, supporting a multi-allele approach for developing polymorphic antigens as malaria vaccines

Implementing parasite genotyping into national surveillance frameworks: Feedback from control programmes and researchers in the Asia-pacific region

The Asia-Pacific region faces formidable challenges in achieving malaria elimination by the proposed target in 2030. Molecular surveillance of Plasmodium parasites can provide important information on malaria transmission and adaptation, which can inform national malaria control programmes (NMCPs) in decision-making processes. In November 2019 a parasite genotyping workshop was held in Jakarta, Indonesia, to review molecular approaches for parasite surveillance and explore ways in which these tools can be integrated into public health systems and inform policy. The meeting was attended by 70 participants from 8 malaria-endemic countries and partners of the Asia Pacific Malaria Elimination Network. The participants acknowledged the utility of multiple use cases for parasite genotyping including: quantifying the prevalence of drug resistant parasites, predicting risks of treatment failure, identifying major routes and reservoirs of infection, monitoring imported malaria and its contribution to local transmission, characterizing the origins and dynamics of malaria outbreaks, and estimating the frequency of Plasmodium vivax relapses. However, the priority of each use case varies with different endemic settings. Although a one-size-fits-all approach to molecular surveillance is unlikely to be applicable across the Asia-Pacific region, consensus on the spectrum of added-value activities will help support data sharing across national boundaries. Knowledge exchange is needed to establish local expertise in different laboratory-based methodologies and bioinformatics processes. Collaborative research involving local and international teams will help maximize the impact of analytical outputs on the operational needs of NMCPs. Research is also needed to explore the cost-effectiveness of genetic epidemiology for different use cases to help to leverage funding for wide-scale implementation. Engagement between NMCPs and local researchers will be critical throughout this process