108 research outputs found
Delta-Vs and Design Reference Mission Scenarios for Mars Missions
Before setting out on any long journey, it is important to first have an idea about how to get there, how long it might take, and how much it will cost. Primarily, the answers depend upon where you are starting and where you wish to go. In the formulative stages of any mission to Mars, having quick estimates of answers to these basic questions will aid in the efficient exploration of the trade space. In this paper, we present a “mileage chart” of sorts illustrating the range of ΔV’s and times-of-flight (TOF) between various starting and stopping points between Earth and Mars. This paper expands upon a chart from a previous work by the authors. We discuss the methodologies used to calculate or estimate expected values and reasonable ranges, including some more detailed specific examples
Evidence for a Semisolid Phase State of Aerosols and Droplets Relevant to the Airborne and Surface Survival of Pathogens
The phase state of respiratory aerosols and droplets has been linked to the humidity-dependent survival of pathogens such as SARS-CoV-2. To inform strategies to mitigate the spread of infectious disease, it is thus necessary to understand the humidity-dependent phase changes associated with the particles in which pathogens are suspended. Here, we study phase changes of levitated aerosols and droplets composed of model respiratory compounds (salt and protein) and growth media (organic-inorganic mixtures commonly used in studies of pathogen survival) with decreasing relative humidity (RH). Efflorescence was suppressed in many particle compositions and thus unlikely to fully account for the humidity-dependent survival of viruses. Rather, we identify organic-based, semisolid phase states that form under equilibrium conditions at intermediate RH (45 to 80%). A higher-protein content causes particles to exist in a semisolid state under a wider range of RH conditions. Diffusion and, thus, disinfection kinetics are expected to be inhibited in these semisolid states. These observations suggest that organic-based, semisolid states are an important consideration to account for the recovery of virus viability at low RH observed in previous studies. We propose a mechanism in which the semisolid phase shields pathogens from inactivation by hindering the diffusion of solutes. This suggests that the exogenous lifetime of pathogens will depend, in part, on the organic composition of the carrier respiratory particle and thus its origin in the respiratory tract. Furthermore, this work highlights the importance of accounting for spatial heterogeneities and time-dependent changes in the properties of aerosols and droplets undergoing evaporation in studies of pathogen viability
Lee Silverman Voice Treatment versus NHS Speech and Language Therapy versus control for dysarthria in Parkinson’s disease (PD COMM):a UK, multicentre, pragmatic, randomised controlled trial
Objectives: We aimed to assess the clinical effectiveness of two speech and language therapy (SLT) approaches versus no speech and language therapy for dysarthria in people with Parkinson’s disease. Design: This was a pragmatic, UK-wide, multicentre, three-arm, parallel group, unblinded, randomised controlled trial. Participants were randomly assigned using minimisation in a 1:1:1 ratio to Lee Silverman Voice Treatment (LSVT LOUD®), NHS SLT, or no SLT. Analyses were based on the intention to treat principle.Setting: The speech and language therapy interventions were delivered in outpatient or home settings.Participants: Between September 2016 and March 2020, 388 people with Parkinson’s disease and dysarthria were randomised into the trial: 130 to LSVT LOUD®, 129 to NHS SLT, and 129 to no SLT.Interventions: Lee Silverman Voice Treatment (LSVT LOUD®) consisted of four, face-to-face or remote, 50-minute sessions each week delivered over 4 weeks. Home-based practice activities were set for up to 5 to 10 minutes daily on treatment days and 15 minutes twice daily on non-treatment days. NHS Speech and language therapy (NHS SLT) dosage was determined by the local therapist in response to individual participants’ needs. Prior research suggested that NHS SLT participants would receive an average of one session per week over 6 to 8 weeks. Local practices for NHS SLT were accepted, except for those within the LSVT LOUD® protocol. Main outcome measures: The primary outcome was the self-reported Voice Handicap Index (VHI) total score at 3 months.Results: People randomised to LSVT LOUD® reported lower VHI scores at 3 months post-randomisation than those who were randomised to no SLT (-8·0 points (99%CI: -13·3 to -2·6); p = 0·0001). There was no evidence of a difference in VHI scores between NHS SLT and no SLT (1·7 points; (99%Cl: -3·8 to 7·1); p = 0·43). Patients randomised to LSVT LOUD® also reported lower VHI scores than those randomised to NHS SLT (-9·6 points; (99%CI: -14·9 to -4·4); p < 0.0001). There were 93 adverse events (predominately vocal strain) in the LSVT LOUD® group, 46 in the NHS SLT group, and none in the no SLT group. There were no serious adverse events. Conclusions: LSVT LOUD® was more effective at reducing the participant reported impact of voice problems than no SLT and NHS SLT. NHS SLT showed no evidence of benefit compared to no SLT. Trial registration: The completed trial registration is ISRCTN12421382. Funding: NIHR HTA Programme, project number HTA 10/135/02. <br/
Lee Silverman Voice Treatment versus NHS Speech and Language Therapy versus control for dysarthria in Parkinson’s disease (PD COMM):a UK, multicentre, pragmatic, randomised controlled trial
Objectives: We aimed to assess the clinical effectiveness of two speech and language therapy (SLT) approaches versus no speech and language therapy for dysarthria in people with Parkinson’s disease. Design: This was a pragmatic, UK-wide, multicentre, three-arm, parallel group, unblinded, randomised controlled trial. Participants were randomly assigned using minimisation in a 1:1:1 ratio to Lee Silverman Voice Treatment (LSVT LOUD®), NHS SLT, or no SLT. Analyses were based on the intention to treat principle.Setting: The speech and language therapy interventions were delivered in outpatient or home settings.Participants: Between September 2016 and March 2020, 388 people with Parkinson’s disease and dysarthria were randomised into the trial: 130 to LSVT LOUD®, 129 to NHS SLT, and 129 to no SLT.Interventions: Lee Silverman Voice Treatment (LSVT LOUD®) consisted of four, face-to-face or remote, 50-minute sessions each week delivered over 4 weeks. Home-based practice activities were set for up to 5 to 10 minutes daily on treatment days and 15 minutes twice daily on non-treatment days. NHS Speech and language therapy (NHS SLT) dosage was determined by the local therapist in response to individual participants’ needs. Prior research suggested that NHS SLT participants would receive an average of one session per week over 6 to 8 weeks. Local practices for NHS SLT were accepted, except for those within the LSVT LOUD® protocol. Main outcome measures: The primary outcome was the self-reported Voice Handicap Index (VHI) total score at 3 months.Results: People randomised to LSVT LOUD® reported lower VHI scores at 3 months post-randomisation than those who were randomised to no SLT (-8·0 points (99%CI: -13·3 to -2·6); p = 0·0001). There was no evidence of a difference in VHI scores between NHS SLT and no SLT (1·7 points; (99%Cl: -3·8 to 7·1); p = 0·43). Patients randomised to LSVT LOUD® also reported lower VHI scores than those randomised to NHS SLT (-9·6 points; (99%CI: -14·9 to -4·4); p < 0.0001). There were 93 adverse events (predominately vocal strain) in the LSVT LOUD® group, 46 in the NHS SLT group, and none in the no SLT group. There were no serious adverse events. Conclusions: LSVT LOUD® was more effective at reducing the participant reported impact of voice problems than no SLT and NHS SLT. NHS SLT showed no evidence of benefit compared to no SLT. Trial registration: The completed trial registration is ISRCTN12421382. Funding: NIHR HTA Programme, project number HTA 10/135/02. <br/
Spheres of Practice for the Co-design of Wearables
As expectations within the area of smart textiles increasingly become informed and driven by technological developments, the disciplinary boundaries and relationship between user and technological innovation will unavoidably transform. The authors venture that new paradigms of collaborative practice will inevitably develop between design and science, to more fully realize both the opportunities and contexts that wearable textiles offer. Drawing on previous work by the authors namely Molecular Imprinted Textiles (MIT - 2009/10), Future Textile Visions (FTV - 2010/11), Design Specks: Connecting People with Speckled Computing (2012/13), Second Skin (2013/14), and The S*** Word: Designing the Empathic Underwardrobe (2014), a model is proposed to more clearly understand and navigate between design, technology and application, and more importantly, between our cultural understanding of the user and the wearer. This paper reflects on a series of projects that inform a methodological approach: a process of asking questions; developing scenarios; exploring materials and making; generating concepts and building prototypes. Each project involved collaborations between design, academics, users and industry, and a form of co-design, where knowledge exchange was central, design was the intermediary, and the goal was to understand the drivers and the stakeholders. Simultaneously, this research sought to better understand and communicate the development of more empathic textile and fashion artifacts, and solutions. Co-design in this context is seen as a core approach to shifting the balance from technology as merely adjunct, or as a hook for marketers and users, to a more informed and harmonised position, where technology sits proximally and comfortably. The notion of interdisciplinary understanding, which tracks across domains of product, fashion and textiles, presents an approach where the application is still emerging. Through analysis of this progressive series of projects, the authors suggest that there is an opportunity to explore the inherent connectedness that textiles might offer for the integration and embedding of technology within material as a means to embrace these affordance opportunities. Central to this notion is the realisation of opportunities arising from dialogue and collaborative making (i.e. co-design), and for exploring the transformative notions of the user and the wearer. This paper led the authors to pose a set of questions that align to a four stage design process: Research, Define, Develop, Reflect, to frame findings and insights, and to outline the potential for future opportunities of working with technology to achieve the making and wearing of desirable materializations on the body
Social Context–Induced Song Variation Affects Female Behavior and Gene Expression
Social cues modulate the performance of communicative behaviors in a range of species, including humans, and such changes can make the communication signal more salient. In songbirds, males use song to attract females, and song organization can differ depending on the audience to which a male sings. For example, male zebra finches (Taeniopygia guttata) change their songs in subtle ways when singing to a female (directed song) compared with when they sing in isolation (undirected song), and some of these changes depend on altered neural activity from a specialized forebrain-basal ganglia circuit, the anterior forebrain pathway (AFP). In particular, variable activity in the AFP during undirected song is thought to actively enable syllable variability, whereas the lower and less-variable AFP firing during directed singing is associated with more stereotyped song. Consequently, directed song has been suggested to reflect a “performance” state, and undirected song a form of vocal motor “exploration.” However, this hypothesis predicts that directed–undirected song differences, despite their subtlety, should matter to female zebra finches, which is a question that has not been investigated. We tested female preferences for this natural variation in song in a behavioral approach assay, and we found that both mated and socially naive females could discriminate between directed and undirected song—and strongly preferred directed song. These preferences, which appeared to reflect attention especially to aspects of song variability controlled by the AFP, were enhanced by experience, as they were strongest for mated females responding to their mate's directed songs. We then measured neural activity using expression of the immediate early gene product ZENK, and found that social context and song familiarity differentially modulated the number of ZENK-expressing cells in telencephalic auditory areas. Specifically, the number of ZENK-expressing cells in the caudomedial mesopallium (CMM) was most affected by whether a song was directed or undirected, whereas the caudomedial nidopallium (NCM) was most affected by whether a song was familiar or unfamiliar. Together these data demonstrate that females detect and prefer the features of directed song and suggest that high-level auditory areas including the CMM are involved in this social perception
World radiocommunication conference 12 : implications for the spectrum eco-system
Spectrum allocation is once more a key issue facing the global telecommunications industry. Largely overlooked in current debates, however, is the World Radiocommunication Conference (WRC). Decisions taken by WRC shape the future roadmap of the telecommunications industry, not least because it has the ability to shape the global spectrum allocation framework. In the debates of WRC-12 it is possible to identify three main issues: enhancement of the international spectrum regulatory framework, regulatory measures required to introduce Cognitive Radio Systems (CRS) technologies; and, additional spectrum allocation to mobile service. WRC-12 eventually decided not to change the current international radio regulations with regard to the first two issues and agreed to the third issue. The main implications of WRC-12 on the spectrum ecosystem are that most of actors are not in support of the concept of spectrum flexibility associated with trading and that the concept of spectrum open access is not under consideration. This is explained by the observation that spectrum trading and spectrum commons weaken state control over spectrum and challenge the main principles and norms of the international spectrum management regime. In addition, the mobile allocation issue has shown the lack of conformity with the main rules of the regime: regional spectrum allocation in the International Telecommunication Union (ITU) three regions, and the resistance to the slow decision making procedures. In conclusion, while the rules and decision-making procedures of the international spectrum management regime were challenged in the WRC-12, the main principles and norms are still accepted by the majority of countries
Deliberative and epistemic approaches to democracy
Deliberative and epistemic approaches to democracy are two important dimensions of contemporary democratic theory. This chapter studies these dimensions in the emerging ecosystem of civic and political participation tools, and appraises their collective value in a new distinct concept: linked democracy. Linked democracy is the distributed, technology-supported collective decision-making process, where data, information and knowledge are connected and shared by citizens online. Innovation and learning are two key elements of Athenian democracies which can be facilitated by the new digital technologies, and a cross-disciplinary research involving computational scientists and democratic theorists can lead to new theoretical insights of democracy
Duffy blood group gene polymorphisms among malaria vivax patients in four areas of the Brazilian Amazon region
<p>Abstract</p> <p>Background</p> <p>Duffy blood group polymorphisms are important in areas where <it>Plasmodium vivax </it>predominates, because this molecule acts as a receptor for this protozoan. In the present study, Duffy blood group genotyping in <it>P. vivax </it>malaria patients from four different Brazilian endemic areas is reported, exploring significant associations between blood group variants and susceptibility or resistance to malaria.</p> <p>Methods</p> <p>The <it>P. vivax </it>identification was determined by non-genotypic and genotypic screening tests. The Duffy blood group was genotyped by PCR/RFLP in 330 blood donors and 312 malaria patients from four Brazilian Amazon areas. In order to assess the variables significance and to obtain independence among the proportions, the Fisher's exact test was used.</p> <p>Results</p> <p>The data show a high frequency of the <it>FYA/FYB </it>genotype, followed by <it>FYB/FYB, FYA/FYA</it>, <it>FYA/FYB-33 </it>and <it>FYB/FYB-33</it>. Low frequencies were detected for the <it>FYA/FY</it><sup><it>X</it></sup>, <it>FYB/FY</it><sup><it>X</it></sup>, <it>FYX/FY</it><sup><it>X </it></sup>and <it>FYB-33/FYB-33 </it>genotypes. Negative Duffy genotype (<it>FYB-33/FYB-33</it>) was found in both groups: individuals infected and non-infected (blood donors). No individual carried the <it>FY</it><sup><it>X</it></sup><it>/FYB-33 </it>genotype. Some of the Duffy genotypes frequencies showed significant differences between donors and malaria patients.</p> <p>Conclusion</p> <p>The obtained data suggest that individuals with the <it>FYA/FYB </it>genotype have higher susceptibility to malaria. The presence of the <it>FYB-33 </it>allele may be a selective advantage in the population, reducing the rate of infection by <it>P. vivax </it>in this region. Additional efforts may contribute to better elucidate the physiopathologic differences in this parasite/host relationship in regions endemic for <it>P. vivax </it>malaria, in particular the Brazilian Amazon region.</p
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