1,612 research outputs found
Environmental Enrichment in the ISS Rodent Habitat Hardware System
Responses of animals exposed to microgravity during in-space experiments were reviewed from NASAs and ESA available video recording archives. These documented observation of animal behavior, as well as the range and level of activities during spaceflight, clearly demonstrate that weightlessness conditions and the extreme novelty of the surroundings exert damaging psychological stresses on the inhabitants. In response to a recognized need for in-flight animals to improve their wellbeing we propose to reduce such stresses by shaping and interrelating structures and surroundings to satisfying vital physiological needs of inhabitants. Rodent Habitat Hardware System based housing facility incorporating a tubing network system, to maintain and monitor rodent health environment with advanced accessories has been proposed. The new tubing configuration was found suitable for further incorporation of innovative monitoring technology and accessories in the animal holding habitat unit which allow to monitor in real-time the most valuable health related biological parameter under weightlessness environment of spaceflight
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Stochastic Optimization of Building Control Systems for Mixed-Mode Buildings
Mixed mode (MM) buildings are a subset of low-energy buildings that employ both natural mechanical ventilation, often using manually operable windows for natural ventilation, along with other low-exergy cooling systems such as radiant cooling. This combination of systems has proven difficult to control in practice, in particular due to the potential for occupants to significantly impact building performance. Model predictive control (MPC) and rule extraction are promising methods for optimizing MM building systems in an offline setting, and for generating usable control rules that can be implemented in practice. Simulation studies were performed to investigate the impact that occupant actions have on mixed mode buildings, and to improve the performance of natural ventilation controls in mixed mode buildings while accounting for uncertain occupant behavior. Results show that accounting for occupant behavior in building simulations provides useful insight into the robustness of different control strategies with respect to the impact of occupant actions. Two approaches to improving natural ventilation controls are applied to a physical building; the first seeks to improve on existing control logic by optimizing setpoints, while the second employs MPC and rule extraction to generate all new control logic. Each approach provides insight into potential flaws in existing logic and suggests revised logic that leads to better performance in the presence of occupant behavior. In a final study, rule extraction is applied to optimal control datasets for multiple seasons and locations to develop control rules that approximate optimal controller performance. Converting state information to state-change information prior to applying rule extraction is shown to improve the performance of extracted rules, and it is shown that rules generated using data for a single season or location do not transfer well to other seasons or locations
Environmental Enrichment in the ISS Rodent Habitat Hardware System
Responses of animals exposed to microgravity during in-space experiments were observed via available video recording stored in the NASA Ames Life Sciences Data Archive. These documented observations of animal behavior, as well as the range and level of activities during spaceflight, demonstrate that weightlessness conditions and the extreme novelty of the surroundings may exert damaging psychological stresses on the inhabitants. In response to a recognized need for in-flight animals to improve their wellbeing we propose to reduce such stresses by shaping and interrelating structures and surroundings to satisfying vital physiological needs of inhabitants. A Rodent Habitat Hardware System (RHHS) based housing facility incorporating a tubing network system, to maintain and monitor rodent health environment with advanced accessories has been proposed. Placing mice in a tubing-configured environment creates more natural space-restricted nesting environment for rodents, thereby facilitating a more comfortable transition to living in microgravity. A sectional tubing structure of the RHHS environment will be more beneficial under microgravity conditions than the provision of a larger space area that is currently utilized. The new tubing configuration was found suitable for further incorporation of innovative monitoring technology and accessories in the animal holding habitat unit which allow to monitor in real-time monitoring of valuable health related biological parameters under weightlessness environment of spaceflight
On the degrees of freedom of lattice electrodynamics
Using Euler's formula for a network of polygons for 2D case (or polyhedra for
3D case), we show that the number of dynamic\textit{\}degrees of freedom of the
electric field equals the number of dynamic degrees of freedom of the magnetic
field for electrodynamics formulated on a lattice. Instrumental to this
identity is the use (at least implicitly) of a dual lattice and of a (spatial)
geometric discretization scheme based on discrete differential forms. As a
by-product, this analysis also unveils a physical interpretation for Euler's
formula and a geometric interpretation for the Hodge decomposition.Comment: 14 pages, 6 figure
Massage Gun Use at a Lower Frequency Does Not Alter Blood Flow
Data has shown that whole body vibration can affect blood flow velocity in arteries and improves cutaneous blood flow. However, there is very limited information available on therapeutic localized vibration. Massage guns have become very popular with little to no research validating their efficacy. It is currently unknown if massages guns can affect arterial blood flow. PURPOSE: To determine if massage gun treatment at 30Hz improves and retains blood flow in the popliteal artery as compared to a control condition. METHODS: There were 12 participants in this study (8 males and 4 females). The mean age was 22.7±1.6 yrs, the mean height was 181.1± 11.8 cm, and the mean weight was 78.2±16.2 kg. Participants wore shorts that allowed us to access their popliteal artery using ultrasound imaging. Participants wore electrodes to control the measurement of blood flow from widest artery diameter. Participants lay prone with a foam roller under their ankles to slightly elevate their feet. After ten minutes of rest, ultrasound imaging was used to find the participant’s popliteal artery behind the knee and took two baseline measurements. We measured the mean velocity of blood flow (TAmean) and volume flow (VolF). We measured subjects on 4 different days (30Hz at 5 minutes, 30Hz 10 minutes, Control 5 minutes, Control 10 minutes). Measurements of TAmean and VolF were measured at multiple time points after treatment. RESULTS: A two-factor repeated measures analysis was performed. Each subject was measured under all levels of condition (1=30hz 5 min, 4=Control 5 mi, 5=30hz 10 min, 8=Control 10 min) and time (baseline, post, post1-5, 7, 9, 11, 13, 15, 17, 19). TA mean is significantly greater in 30Hz versus control (p=0.0349). TAmean varies across time, and the effect of the condition on TAmean is related to time (p=0.0104). There is not a significant difference in flow between 30Hz and control (p=0.2425). Blood flow varies across time (pCONCLUSION: Use of a massage gun at a lower frequency setting of 30Hz may cause slight increases in velocity but does not increase mean blood flow as compared to control. Lower frequency settings on massage guns may not be benefit blood flow in the massaged muscle group
Using a comprehensive audit to identify local context prior to care bundle design and implementation for inadvertent perioperative hypothermia in colorectal surgery
© Background The first step in bundle design or implementation is to identify the problem being addressed. Several validated approaches are recommended to facilitate this. These include using systematic reviews, adverse event triggers and risk assessment tools. However, these methods do not fully take the local context into account, which will limit the effectiveness of the bundle. Aim This study explores the potential benefit of using a comprehensive audit to identify an organisation's local context prior to designing and implementing a care bundle. Method A comprehensive audit comprising observations of four patient journeys, interviews with 21 staff and clinical data was carried out at one large National Health Service trust in England. A patient warming care bundle was used as the exemplar. Findings Each of the three data collection methods identified specific local practices which would be addressed within the planning and implementation stages of a care bundle. These practices would not have been identified through other recommended methods. Conclusion A comprehensive audit, comprising observations, interviews and clinical data is a successful method to identify local contextual issues prior to care bundle implementation
Abnormal coagulation and enhanced fibrinolysis due to lysinuric protein intolerance associates with bleeds and renal impairment
Introduction: Lysinuric protein intolerance (LPI), a rare autosomal recessive transport disorder of cationic amino acids lysine, arginine and ornithine, affects intestines, lungs, liver and kidneys. LPI patients may display potentially life-threatening bleeding events, which are poorly understood. Aims: To characterize alterations in haemostatic and fibrinolytic variables associated with LPI. Methods: We enrolled 15 adult patients (8 female) and assessed the clinical ISTH/ SSC-BAT bleeding score (BS). A variety of metabolic and coagulation assays, including fibrin generation test derivatives, clotting time (CT) and clot lysis time (CLT), thromboelastometry (ROTEM), and PFA-100 and Calibrated Automated Thrombogram (CAT), were used. Results: All patients had mild-to-moderate renal insufficiency, and moderate bleeding tendency (BS 4) without spontaneous bleeds. Mild anaemia and thrombocytopenia occurred. Traditional clotting times were normal, but in contrast, CT in fibrin generation test, and especially ROTEM FIBTEM was abnormal. The patients showed impaired primary haemostasis in PFA, irrespective of normal von Willebrand factor activity, but together with lowered fibrinogen and FXIII. Thrombin generation (TG) was reduced in vitro, according to CAT-derived endogenous thrombin potential, but in vivo TG was enhanced in the form of circulating prothrombin fragment 1 and 2 values. Very high D-dimer and plasmin-alpha 2-antiplasmin (PAP) complex levels coincided with shortened CLT in vitro. Conclusions: Defective primary haemostasis, coagulopathy, fibrin abnormality (FIBTEM, CT and CLT), low TG in vitro and clearly augmented fibrinolysis (PAP and D-dimer) in vivo were all detected in LPI. Altered fibrin generation and hyperfibrinolysis were associated with the metabolic and renal defect, suggesting a pathogenetic link in LPI.Peer reviewe
A New Spherical Harmonics Scheme for Multi-Dimensional Radiation Transport I: Static Matter Configurations
Recent work by McClarren & Hauck [29] suggests that the filtered spherical
harmonics method represents an efficient, robust, and accurate method for
radiation transport, at least in the two-dimensional (2D) case. We extend their
work to the three-dimensional (3D) case and find that all of the advantages of
the filtering approach identified in 2D are present also in the 3D case. We
reformulate the filter operation in a way that is independent of the timestep
and of the spatial discretization. We also explore different second- and
fourth-order filters and find that the second-order ones yield significantly
better results. Overall, our findings suggest that the filtered spherical
harmonics approach represents a very promising method for 3D radiation
transport calculations.Comment: 29 pages, 13 figures. Version matching the one in Journal of
Computational Physic
Effect of Localized Vibration Using Massage Gun at 40hz and 50hz on Blood Flow
Data has shown that whole body vibration can positively affect blood flow, however, there are very few studies on the effect of localized therapeutic vibration on arterial blood flow. Occupational studies looking at localized vibration effects on skin blood flow normally include high frequency settings. In the last few years, massage guns have become popular, but they operate at lower frequencies. Currently, there is no data on the effects of localized vibration from massage guns on arterial blood flow. PURPOSE: To compare the effects of two different frequencies of localized vibration on blood flow in the popliteal artery. METHODS: 12 subjects participated in this study (8 males and 4 females). Mean age was 22.7±1.6 years; mean height was 181.1±11.8 cm; mean weight was 78.2±16.2 kg. Participants wore shorts to give access to the popliteal artery. Participants were hooked to ECG leads to control measurement of artery diameter and then laid on a treatment table in a prone position with a foam roller under their ankles. Once at resting heart rate, baseline blood flow readings were taken using ultrasound, which measured TA Mean and Volume Flow. The participants were then randomly given a 5-minute treatment of control with no vibration or vibration at 40hz or 50hz. Blood flow readings were taken immediately post-treatment and then every minute for 5 minutes after. RESULTS: A two-factor repeated measures analysis was performed. Each subject was measured under all levels of condition (Control 5 min, 40hz 5 min, and 50hz 5 min) and time (baseline, post, post1-5). TA Mean and Volume Flow for both 40hz and 50hz were significantly greater than control (p=0.0020 and p=0.0110 respectively). The effect of time was significant (
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