3,185 research outputs found
Inhaled particle counts on bicycle commute routes of low and high proximity to motorised traffic
Frequent exposure to ultrafine particles (UFP) is associated with detrimental effects on cardiopulmonary function and health. UFP dose and therefore the associated health risk are a factor of exposure frequency, duration, and magnitude of (therefore also proximity to) a UFP emission source. Bicycle commuters using on-road routes during peak traffic times are sharing a microenvironment with high levels of motorised traffic, a major UFP emission source. Inhaled particle counts were measured along popular pre-identified bicycle commute route alterations of low (LOW) and high (HIGH) motorised traffic to the same inner-city destination at peak commute traffic times. During commute, real-time particle number concentration (PNC; mostly in the UFP range) and particle diameter (PD), heart and respiratory rate, geographical location, and meteorological variables were measured. To determine inhaled particle counts, ventilation rate was calculated from heart-rate-ventilation associations, produced from periodic exercise testing. Total mean PNC of LOW (compared to HIGH) was reduced (1.56 x e4 ± 0.38 x e4 versus 3.06 x e4 ± 0.53 x e4 ppcc; p = 0.012). Total estimated ventilation rate did not vary significantly between LOW and HIGH (43 ± 5 versus 46 ± 9 L•min; p = 0.136); however, due to total mean PNC, accumulated inhaled particle counts were 48% lower in LOW, compared to HIGH (7.6 x e8 ± 1.5 x e8 versus 14.6 x e8 ± 1.8 x e8; p = 0.003). For bicycle commuting at peak morning commute times, inhaled particle counts and therefore cardiopulmonary health risk may be substantially reduced by decreasing exposure to motorised traffic, which should be considered by both bicycle commuters and urban planners
WASP - Wireless Analog Sensor Platform
WASP’s goal is to augment and eventually replace the bulky, costly, and complex data acquisition systems used for vibrational reliability tests on satellites. As a mechanism to guarantee that a spacecraft is mechanically durable and strong enough to withstand the acceleration forces experienced on the vessel during launch, companies conduct vibrational experiments on their spacecrafts by subjecting them to high G-force events. Using wired accelerometers connected to obstructive cables, the mounting process and test setups required to perform such experiments are expensive, laborious, and have the potential to generate measurement inaccuracies. We developed a low-cost, battery-powered module, designed for engineers, to replace the current sensors and data acquisition systems with a wireless solution. This will enable precise testing of conditions on a smaller time frame and at a lower cost and help eliminate the disadvantages of a wired system. A custom circuit board has been fabricated containing the critical measurement and processing components required to realize this objective, as well as a complete software solution to facilitate data transmission to a wireless router over WiFi
Platypus: Quick, Cheap, and Powerful Refinement of LLMs
We present , a family of fine-tuned and merged Large
Language Models (LLMs) that achieves the strongest performance and currently
stands at first place in HuggingFace's Open LLM Leaderboard as of the release
date of this work. In this work we describe (1) our curated dataset
, that is a subset of other open datasets and which
(2) our process of fine-tuning and merging
LoRA modules in order to conserve the strong prior of pretrained LLMs, while
bringing specific domain knowledge to the surface (3) our efforts in checking
for test data leaks and contamination in the training data, which can inform
future research. Specifically, the Platypus family achieves strong performance
in quantitative LLM metrics across model sizes, topping the global Open LLM
leaderboard while using just a fraction of the fine-tuning data and overall
compute that are required for other state-of-the-art fine-tuned LLMs. In
particular, a 13B Platypus model can be trained on A100 GPU
using 25k questions in 5 hours. This is a testament of the quality of our
Open-Platypus dataset, and opens opportunities for more improvements in the
field. Project page: https://platypus-llm.github.i
Pacing during an ultramarathon running event in hilly terrain
PURPOSE: The dynamics of speed selection as a function of
distance, or pacing, are used in recreational, competitive, and
scientific research situations as an indirect measure of the
psycho-physiological status of an individual. The purpose of
this study was to determine pacing on level, uphill and downhill
sections of participants in a long (>80 km) ultramarathon
performed on trails in hilly terrain. METHODS: Fifteen
ultramarathon runners competed in a 173 km event (five finished
at 103 km) carrying a Global-Positioning System (GPS) device.
Using the GPS data, we determined the speed, relative to average
total speed, in level (LEV), uphill (UH) and downhill (DH)
gradient categories as a function of total distance, as well as
the correlation between overall performance and speed
variability, speed loss, and total time stopped. RESULTS: There
were no significant differences in normality, variances or means
in the relative speed in 173-km and 103-km participants.
Relative speed decreased in LEV, UH and DH. The main component
of speed loss occurred between 5% and 50% of the event distance
in LEV, and between 5% and 95% in UH and DH. There were no
significant correlations between overall performance and speed
loss, the variability of speed, or total time stopped.
CONCLUSIONS: Positive pacing was observed at all gradients, with
the main component of speed loss occurring earlier (mixed
pacing) in LEV compared to UH and DH. A speed reserve (increased
speed in the last section) was observed in LEV and UH. The
decrease in speed and variability of speed were more important
in LEV and DH than in UH. The absence of a significant
correlation between overall performance and descriptors of
pacing is novel and indicates that pacing in ultramarathons in
trails and hilly terrain differs to other types of running
events
Mechanistic Insights for Magnetic Imaging and Control of Cellular Function
The vast biomolecular toolkit for optical imaging and control of cellular function has revolutionized the study of in vitro samples and superficial tissues in living organisms but leaves deep tissue unexplored. To look deeper in tissue and observe system-level biological function in large organisms requires a modality that exploits a more penetrant form of energy than visible light. Magnetic imaging with MRI reveals the previously unseen, with endogenous tissue contrast and practically infinite penetration depth. While these clear advantages have made MRI a cornerstone of modern medical imaging, the sparse library of molecular agents for MRI have severely limited its utility for studies of cellular function in vivo. The development of new molecular agents for MRI has suffered from a lack of tools to study the connection between changes in the microscale cellular environment and the corresponding millimeter-scale MRI contrast. Bridging this gap requires revisiting the mechanistic underpinnings of MRI contrast, casting aside some of the simplifications that smooth over sub-voxel heterogeneity that is rich with information pertinent to the underlying cell state.
Here, we will demonstrate theoretical, computational, and experimental connections between subtle changes in microscale cellular environment and resultant MRI contrast. After reviewing some foundational principles of MRI physics in the first chapter, the second chapter of the thesis will explore computational models that have significantly enhanced the development of genetically encoded agents for MRI, including the first genetically encoded contrast agent for diffusion weighted imaging. By improving the efficacy of these genetically encoded agents, we unlock MRI reporter genes for in vivo studies of cellular dynamics much in the same way that the engineering of Green Fluorescent Protein has dramatically improved in vitro studies of cellular function.
In the third chapter, we introduce our study that maps microscale magnetic fields in cells and tissues and connects those magnetic fields to MRI contrast. Such a connection has previously been experimentally intractable due to the lack of methods to resolve small magnetic perturbations with microscale resolution. To overcome this challenge, we leverage nitrogen vacancy diamond magnetometry to optically probe magnetic fields in cells with sub-micron resolution and nanotesla sensitivity, together with iterative localization of field sources and Monte Carlo simulation of nuclear spins to predict the corresponding MRI contrast. We demonstrate the utility of this technology in an in vitro model of macrophage iron uptake and histological samples from a mouse model of hepatic iron overload. In addition, we show that this technique can follow dynamic changes in the magnetic field occurring during contrast agent endocytosis by living cells. This approach bridges a fundamental gap between an MRI voxel and its microscopic constituents and provides a new capability for noninvasive imaging of opaque tissues.
In the fourth chapter, we focus on the use of magnetic fields to perturb, rather than image, biological function. Recent suggestions of nanoscale heat confinement on the surface of synthetic and biogenic magnetic nanoparticles during heating by radiofrequency alternating magnetic fields have generated intense interest due to the potential utility of this phenomenon in non-invasive control of biomolecular and cellular function. However, such confinement would represent a significant departure from classical heat transfer theory. We present an experimental investigation of nanoscale heat confinement on the surface of several types of iron oxide nanoparticles commonly used in biological research, using an all-optical method devoid of potential artifacts present in previous studies. By simultaneously measuring the fluorescence of distinct thermochromic dyes attached to the particle surface or dissolved in the surrounding fluid during radiofrequency magnetic stimulation, we found no measurable difference between the nanoparticle surface temperature and that of the surrounding fluid for three distinct nanoparticle types. Furthermore, the metalloprotein ferritin produced no temperature increase on the protein surface, nor in the surrounding fluid. Experiments mimicking the designs of previous studies revealed potential sources of artifacts. These findings inform the use of magnetic nanoparticle hyperthermia in engineered cellular and molecular systems and can help direct future resources towards tractable avenues of magnetic control of cellular function.</p
NSF Graduate Teaching Fellows in K-12 Education at the University of Maine
The program for Graduate Teaching Fellows in K-12 Education at the University of Maine is consistent with the State\u27s legislatively mandated goals for education in Science and Technology. Twelve Fellows are working in four local school districts through this program, which engages colleagues at the University and K-12 schools in transfer of knowledge and curriculum development with respect to topics such as Classifying Living Things, Forestry & Pulp and Paper Studies, and The Hydrological Cycle. The project is providing K-12 students and teachers with access to curriculum development, field trips, technology, and equipment that local school budgets had not provided. A summer science camp is being used in the training program to establish the teaching teams (university faculty and K-12 teachers) that mentor Fellows. The program provides SMET fellowships for the University, professional development for K-12 teachers, important role models and knowledge to K-12 students, and a strong bond between the science faculty of the University and K-12 teachers
Training peers to treat Ebola centre workers with anxiety and depression in Sierra Leone
Background: Following the 2014 Ebola virus disease (EVD) outbreak in West Africa, the UK Department for International Development funded South London and Maudsley National Health Service (NHS) to develop a psychological intervention that ex-Ebola Treatment Centre (ETC) staff could be trained to deliver to their peers to improve mental health in Sierra Leone. /
Aim: The two key aims were to assess the feasibility of training a national team to deliver a cognitive behavioural therapy (CBT)–based group intervention, and to evaluate the effectiveness of the overall intervention within this population. /
Methods: UK clinicians travelled to Sierra Leone to train a small team of ex-ETC staff in a three-phased CBT-based intervention. Standardised clinical measures, as well as bespoke measures, were applied with participants through the intervention to assess changes in mental health symptomology, and the effectiveness of the intervention. /
Results: The results found improvements across all factors of mental health in the bespoke measure from phase 1 to phase 3. Additionally, the majority of standardised clinical measures showed improvements between phase 2 and the start of phase 3, and pre- and post-phase 3. /
Conclusion: Overall, the findings suggest that it is possible to train staff from ETCs to deliver effective CBT interventions to peers. The implications of these results are discussed, including suggestions for future research and clinical intervention implementation within this population. The limitations of this research are also addressed
Private and public modes of bicycle commuting: a perspective on attitude and perception
BACKGROUND: Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting.
METHODS: The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and perception statements. Based on their most common one-way commute trip and willingness to commute by bicycle, subjects were classified into Private Bicycle (PB), public bicycle or Bicing Bicycle (BB), Willing Non-bicycle (WN) and Non-willing Non-bicycle (NN) commuters. After reducing the survey statements through principal component analysis, a multinomial logistic regression model was obtained to evaluate associations between attitudinal and commuter sub-groups.
RESULTS: We included 814 adults in the analysis [51.6% female, mean (SD): age 36.6 (10.3) years]. BB commuters were 2.0 times [95% confidence interval (CI) = 1.1-3.7] less likely to perceive bicycle as a quick, flexible and enjoyable mode compared to PB. BB, WN and NN were 2.5 (95% CI = 1.46-4.24), 2.6 (95% CI = 1.53-4.41) and 2.3 times (95% CI = 1.30-4.10) more likely to perceive benefits of using public bicycles (bicycle maintenance and parking avoidance, low cost and no worries about theft and vandalism) than did PB.
CONCLUSION: Willing non-bicycle and public-bicycle commuters had more favourable perception toward public-shared bicycles compared to private cyclists. Hence, public bicycles may be the impetus for those willing to start bicycle commuting, thereby increasing physical activity levels
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