1,838 research outputs found
WEISS-SAT1: A Student Developed Astrobiology Payload for Small Satellite Microgravity Research
The WeissSat-1 is a novel student developed 1U CubeSat designed to support astrobiology payloads for microgravity research. WeissSat-1 is the premier project of the Weiss CubeSat Development Team (WCDT), which was established in August of 2015. The founding WeissSat-1 team consisted of nine students ranging between the ages of 10-12 years old. The mission was: to design, build, test, and fly a CubeSat into space within three years. WeissSat-1, based on the NearSpace Launch Inc’s 1U FastBus structure, was chosen by ELaNa 24 and manifested to fly in the fourth quarter of 2018. WeissSat-1 will carry a lab-on-a-chip system designed to test and validate the survivability of extremophile bacteria in orbit. WeissSat-1 demonstrates the benefit and the importance of engaging and involving students in space-based scientific research throughout the academic pipeline. This work will discuss in detail the technology of the WeissSat-1 mission, and will discuss its impacts on middle school students and their STEM interests. The WCDT contends that if the respective extremophile bacteria on WeissSat-1 are capable of surviving in space, this may have ramifications for the possibility that bacteria may have transferred between planetary bodies over the life of the solar system
Culex tarsalis is a competent vector species for Cache Valley virus
Background: Cache Valley virus (CVV) is a mosquito-borne orthobunyavirus endemic in North America. The virus is
an important agricultural pathogen leading to abortion and embryonic lethality in ruminant species, especially
sheep. The importance of CVV in human public health has recently increased because of the report of severe
neurotropic diseases. However, mosquito species responsible for transmission of the virus to humans remain to be
determined. In this study, vector competence of three Culex species mosquitoes of public health importance, Culex
pipiens, Cx. tarsalis and Cx. quinquefasciatus, was determined in order to identify potential bridge vector species
responsible for the transmission of CVV from viremic vertebrate hosts to humans.
Results: Variation of susceptibility to CVV was observed among selected Culex species mosquitoes tested in this
study. Per os infection resulted in the establishment of infection and dissemination in Culex tarsalis, whereas Cx.
pipiens and Cx. quinquefasciatus were highly refractory to CVV. Detection of viral RNA in saliva collected from
infected Cx. tarsalis provided evidence supporting its role as a competent vector.
Conclusions: Our study provided further understanding of the transmission cycles of CVV and identifies Cx. tarsalis
as a competent vector
Rationale for the shielding policy for clinically vulnerable people in the UK during the COVID-19 pandemic: a qualitative study
Introduction: Shielding aimed to protect those predicted to be at highest risk from COVID-19 and was uniquely implemented in the UK during the first year of the pandemic from March 2020. As the first stage in the EVITE Immunity evaluation (Effects of shielding for vulnerable people during COVID-19 pandemic on health outcomes, costs and immunity, including those with cancer:quasi-experimental evaluation), we generated a logic model to describe the programme theory underlying the shielding intervention. Design and participants: We reviewed published documentation on shielding to develop an initial draft of the logic model. We then discussed this draft during interviews with 13 key stakeholders involved in putting shielding into effect in Wales and England. Interviews were recorded, transcribed and analysed thematically to inform a final draft of the logic model. Results: The shielding intervention was a complex one, introduced at pace by multiple agencies working together. We identified three core components: agreement on clinical criteria; development of the list of people appropriate for shielding; and communication of shielding advice. In addition, there was a support programme, available as required to shielding people, including food parcels, financial support and social support. The predicted mechanism of change was that people would isolate themselves and so avoid infection, with the primary intended outcome being reduction in mortality in the shielding group. Unintended impacts included negative impact on mental and physical health and well-being. Details of the intervention varied slightly across the home nations of the UK and were subject to minor revisions during the time the intervention was in place. Conclusions: Shielding was a largely untested strategy, aiming to mitigate risk by placing a responsibility on individuals to protect themselves. The model of its rationale, components and outcomes (intended and unintended) will inform evaluation of the impact of shielding and help us to understand its effect and limitations
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Syngeneic animal models of tobacco-associated oral cancer reveal the activity of in situ anti-CTLA-4.
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Tobacco use is the main risk factor for HNSCC, and tobacco-associated HNSCCs have poor prognosis and response to available treatments. Recently approved anti-PD-1 immune checkpoint inhibitors showed limited activity (≤20%) in HNSCC, highlighting the need to identify new therapeutic options. For this, mouse models that accurately mimic the complexity of the HNSCC mutational landscape and tumor immune environment are urgently needed. Here, we report a mouse HNSCC model system that recapitulates the human tobacco-related HNSCC mutanome, in which tumors grow when implanted in the tongue of immunocompetent mice. These HNSCC lesions have similar immune infiltration and response rates to anti-PD-1 (≤20%) immunotherapy as human HNSCCs. Remarkably, we find that >70% of HNSCC lesions respond to intratumoral anti-CTLA-4. This syngeneic HNSCC mouse model provides a platform to accelerate the development of immunotherapeutic options for HNSCC
Infection and transmission of Cache Valley virus by Aedes albopictus and Aedes aegypti mosquitoes
Background:
Cache Valley virus (CVV; Bunyavirales, Peribunyaviridae) is a mosquito-borne arbovirus endemic in North America. Although severe diseases are mainly observed in pregnant ruminants, CVV has also been recognized as a zoonotic pathogen that can cause fatal encephalitis in humans. Human exposures to CVV and its related subtypes occur frequently under different ecological conditions in the New World; however, neurotropic disease is rarely reported. High prevalence rates of neutralizing antibodies have been detected among residents in several Latin American cities. However, zoophilic mosquito species involved in the enzootic transmission are unlikely to be responsible for the transmission leading to human exposures to CVV. Mechanisms that lead to frequent human exposures to CVV remain largely unknown. In this study, competence of two anthropophilic mosquitoes, Aedes albopictus and Ae. aegypti, for CVV was determined using per os infection to determine if these species could play a role in the transmission of CVV in the domestic and peridomestic settings of urban and suburban areas.
Results:
Aedes albopictus were highly susceptible to CVV whereas infection of Ae. aegypti occurred at a significantly lower frequency. Whilst the dissemination rates of CVV were comparable in the two species, the relatively long period to attain maximal infectious titer in Ae. aegypti demonstrated a significant difference in the replication kinetics of CVV in these species. Detection of viral RNA in saliva suggests that both Ae. albopictus and Ae. aegypti are competent vectors for CVV under laboratory conditions.
Conclusions:
Differential susceptibility to CVV was observed in Ae. albopictus and Ae. aegypti, reflecting their relatively different capacities for vectoring CVV in nature. The high susceptibility of Ae. albopictus to CVV observed in this study suggests its potential role as an efficient vector for CVV. Complemented by the reports of multiple CVV isolates derived from Ae. albopictus, our finding provides the basis for how the dispersal of Ae. albopictus across the New World may have a significant impact on the transmission and ecology of CVV
The role and response of primary healthcare services in the delivery of palliative care in epidemics and pandemics : a rapid review to inform practice and service delivery during the COVID-19 pandemic
Background:
The increased number of deaths in the community happening as a result of COVID-19 has caused primary healthcare services to change their traditional service delivery in a short timeframe. Services are quickly adapting to new challenges in the practical delivery of end-of-life care to patients in the community including through virtual consultations and in the provision of timely symptom control.
Aim:
To synthesise existing evidence related to the delivery of palliative and end-of-life care by primary healthcare professionals in epidemics and pandemics.
Design:
Rapid systematic review using modified systematic review methods, with narrative synthesis of the evidence.
Data sources:
Searches were carried out in Medline, Embase, PsychINFO, CINAHL and Web of Science on 7th March 2020.
Results:
Only five studies met the inclusion criteria, highlighting a striking lack of evidence base for the response of primary healthcare services in palliative care during epidemics and pandemics. All were observational studies. Findings were synthesised using a pandemic response framework according to ‘systems’ (community providers feeling disadvantaged in terms of receiving timely information and protocols), ‘space’ (recognised need for more care in the community), ‘staff’ (training needs and resilience) and ‘stuff’ (other aspects of managing care in pandemics including personal protective equipment, cleaning care settings and access to investigations).
Conclusions:
As the COVID-19 pandemic progresses, there is an urgent need for research to provide increased understanding of the role of primary care and community nursing services in palliative care, alongside hospices and community specialist palliative care providers
Biomechanical responses to changes in friction on a clay court surface
Objectives: To examine the influence of clay court frictional properties on tennis players’ biomechanical response.
Design: Repeated measures
Methods: Lower limb kinematic and force data were collected on sixteen university tennis players during 10 x 180° turns (running approach speed 3.9 ± 0.20 m.s-1) on a synthetic clay surface of varying friction levels. To adjust friction levels the volume of sand infill above the force plate was altered (kg per m2 surface area; 12, 16 and 20 kg.m-2). Repeated measures ANOVA and Bonferroni’s corrected alpha post-hoc analyses were conducted to identify significant differences in lower limb biomechanics between friction levels.
Results: Greater sliding distances (Å‹p2= 0.355, p = 0.008) were observed for the lowest friction condition (20 kg.m-2) compared to the 12 and 16 kg.m-2 conditions. No differences in ankle joint kinematics and knee flexion angles were observed. Later peak knee flexion occurred on the 20 kg.m-2 condition compared to the 12 kg.m-2 (Å‹p2 = 0.270, p = 0.023). Lower vertical (Å‹p2 = 0.345, p = 0.027) and shear (Å‹p2 = 0.396, p = 0.016) loading rates occurred for the 20 kg.m2 condition compared to the 16 kg.m2.
Conclusions: Lower loading rates and greater sliding distances when clay surface friction was reduced suggests load was more evenly distributed over time reducing players’ injury risks. The greater sliding distances reported were accompanied with later occurrence of peak knee flexion, suggesting longer time spent braking and a greater requirement for muscular control increasing the likelihood of fatigue
Notch-IGF1 signalling in biliary epithelial cells drives their expansion and inhibits hepatocyte differentiation
[no abstract available
Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment
Here we review how environmental context can be used to interpret whether O2
is a biosignature in extrasolar planetary observations. This paper builds on
the overview of current biosignature research discussed in Schwieterman et al.
(2017), and provides an in-depth, interdisciplinary example of biosignature
identification and observation that serves as a basis for the development of
the general framework for biosignature assessment described in Catling et al.,
(2017). O2 is a potentially strong biosignature that was originally thought to
be an unambiguous indicator for life at high-abundance. We describe the
coevolution of life with the early Earth's environment, and how the interplay
of sources and sinks in the planetary environment may have resulted in
suppression of O2 release into the atmosphere for several billion years, a
false negative for biologically generated O2. False positives may also be
possible, with recent research showing potential mechanisms in exoplanet
environments that may generate relatively high abundances of atmospheric O2
without a biosphere being present. These studies suggest that planetary
characteristics that may enhance false negatives should be considered when
selecting targets for biosignature searches. Similarly our ability to interpret
O2 observed in an exoplanetary atmosphere is also crucially dependent on
environmental context to rule out false positive mechanisms. We describe future
photometric, spectroscopic and time-dependent observations of O2 and the
planetary environment that could increase our confidence that any observed O2
is a biosignature, and help discriminate it from potential false positives. By
observing and understanding O2 in its planetary context we can increase our
confidence in the remote detection of life, and provide a model for
biosignature development for other proposed biosignatures.Comment: 55 pages. The paper is the second in a series of 5 review manuscripts
of the NExSS Exoplanet Biosignatures Workshop. Community commenting is
solicited at https://nexss.info/groups/ebww
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