Simple Maneuvers Research Articles

Iridodialysis repair using a modified sewing machine technique

A large iridodialysis can present with both visual and cosmetic disturbances, and therefore, surgical intervention is indicated. We describe a modified sewing machine technique in repairing large iridodialysis without the indication of an extensive scleral groove. Another modification made was a scleral flap. The scleral flap provides better control on the position of the knot and its whisker, allowing full coverage and eliminating the risk of whisker exposure and eventual conjunctival erosion. This technique for iridodialysis repair provides better cosmetic results, especially for extensive iridodialysis. It is also more economical and involves simple, safe, and efficient surgical maneuvers in repairing iridodialysis.

Neural network reconstruction of the left atrium using sparse catheter paths.

Catheter-based radiofrequency ablation for pulmonary vein isolation has become the first line of treatment for atrial fibrillation in recent years. This requires a rather accurate map of the left atrial sub-endocardial surface including the ostia of the pulmonary veins, which requires dense sampling of the surface and currently takes more than 10min. The focus of this work is to provide left atrial visualization early in the procedure to ease procedure complexity and enable further workflows, such as using catheters that have difficulty sampling the surface. We propose a dense encoder-decoder network with a novel regularization term to reconstruct the shape of the left atrium from partial data which is derived from simple catheter maneuvers. To train the network, we acquire a large dataset of 3D atria shapes and generate corresponding catheter trajectories, from which traversed point clouds are obtained. Once trained, we show that the suggested network can sufficiently approximate the atrium shape based on a given trajectory. We compare several network solutions for the 3D atrium reconstruction. We demonstrate that the solution proposed produces realistic visualization using partial acquisition within a 3-min time interval using human clinical cases.

Prevention and treatment of coronary catheter kinking.

Coronary catheter kinking is an uncommon but potentially catastrophic complication of cardiac catheterization. Although simple maneuvers can often result in resolution of a kink, tighter knots may not respond to such measures. We provide a systematic, stepwise approach to the prevention and treatment of catheter kinking.

Safety Assessment of Sedation Services in Radiology at Shaukat Khanum Memorial Cancer Hospital and Research Center, Peshawar.

The purpose of this retrospective observational study was to evaluate the safety of newly started sedation services in the department of Radiology Shaukat Khanum Memorial Cancer Hospital and Research Center Peshawar, Pakistan. Medical record of the patients who underwent sedation for different types of imaging studies at Shaukat Khanum Memorial Cancer Hospital, Peshawar center were retrospectively reviewed to evaluate the safety outcome of sedation. Process variables included preoperative assessment, obtaining informed consent acquisition, confirmation of nulla per os (NPO) status, monitoring during the procedure, post-anesthetic care unit (PACU) handover, and discharge instructions. The monitored complications included instances of cardiac arrest, respiratory arrest, hypoxia, apnea and vomiting. No major adverse events, such as respiratory or cardiovascular arrest, were observed among the patients in our study. A limited number of cases experienced minor events, specifically hypoxia and apnea, all of which were effectively addressed through simple maneuvers. However, one patient with previously undiagnosed obstructive sleep apnea encountered upper airway obstruction, necessitating the discontinuation of the procedure. Subsequently, all patients were safely discharged to their homes from the recovery area. Sedation in Radiology department can be safely performed by adhering to a structured approach aligned with hospital policies and procedures.

The point on the treatment of arrhythmic storm.

Arrhythmic storm is a clinical emergency associated with high mortality, which requires multi-disciplinary management. Reprogramming of the implantable cardiac defibrillator (ICD) aimed at reducing shocks, adrenergic blockade using beta-blockers, sedation/anxiolysis, and blockade of the stellate ganglion represent the first simple and effective manoeuvres, but further suppression of arrhythmias with antiarrhythmics is often required. A low-risk patient (e.g. monomorphic ventricular tachycardia, functioning ICD, and haemodynamically stable) should be managed with a beta-blocker (possibly non-selective) plus amiodarone, in addition to sedation with a benzodiazepine or dexmedetomidine; in patients at greater risk (high burden and haemodynamic instability), autonomic modulation with blockade of the stellate ganglion and the addition of a second antiarrhythmic (lidocaine) should be considered. In patients refractory to these measures, with advanced heart failure, general anaesthesia with intubation and the establishment of a haemodynamic circulatory support should be considered. Ablation, performed early, appears to be superior in terms of mortality and reduction of future shocks compared with titration of antiarrhythmics.

Thrombotic microangiopathy after kidney transplantation: Expanding etiologic and pathogenetic spectra.

Thrombotic microangiopathy (TMA) is an uncommon but serious complication that not only affects native kidneys but also transplanted kidneys. This review is specifically focused on post-transplant TMA (PT-TMA) involving kidney transplant recipients. Its reported prevalence in the latter population varies from 0.8% to 14% with adverse impacts on both graft and patient survival. It has many causes and associations, and the list of etiologic agents and associations is growing constantly. The pathogenesis is equally varied and a variety of patho genetic pathways lead to the development of microvascular injury as the final common pathway. PT-TMA is categorized in many ways in order to facilitate its management. Ironically, more than one causes are contributory in PT-TMA and it is often difficult to pinpoint one particular cause in an individual case. Pathologically, the hallmark lesions are endothelial cell injury and intravascular thrombi affecting the microvasculature. Early diagnosis and classification of PT-TMA are imperative for optimal outcomes but are challenging for both clinicians and pathologists. The Banff classification has addressed this issue and has developed minimum diagnostic criteria for pathologic diagnosis of PT-TMA in the first phase. Management of the condition is also challenging and still largely empirical. It varies from simple maneuvers, such as plasmapheresis, drug withdrawal or modification, or dose reduction, to lifelong complement blockade, which is very expensive. A thorough understanding of the condition is imperative for an early diagnosis and quick treatment when the treatment is potentially effective. This review aims to increase the awareness of relevant stakeholders regarding this important, potentially treatable but under-recognized cause of kidney allograft dysfunction.

Experimental Nonlinear and Incremental Control Stabilization of a Tail-Sitter UAV with Hardware-in-the-Loop Validation

Tail-sitters aim to combine the advantages of fixed-wing aircraft and rotorcraft but require a robust and fast stabilization strategy to perform vertical maneuvers and transitions to and from aerodynamic flight. The research conducted in this work explores different nonlinear control solutions for the problem of stabilizing a tail-sitter when hovering. For this purpose, the first controller is an existing strategy for tail-sitter control obtained from the literature, the second is an application of Nonlinear Dynamic Inversion (NDI), and the last one is its incremental version, INDI. These controllers were implemented and tuned in a simulation in order to stabilize a model of the tail-sitter, complemented by estimation methods that allow the feedback of the necessary variables. These estimators and controllers were then implemented in a microcontroller and validated in a Hardware-in-the-Loop (HITL) scenario with simple maneuvers in vertical flight. Lastly, the developed control solutions were used to stabilize the aircraft in experimental flight while being monitored by a motion capture system. The experimental results allow the validation of the model of the X-Vert and provide a comparison of the performance of the different control solutions, where the INDI presents itself as a robust control strategy with accurate tracking capabilities and less actuator demand.

Autonomous navigation for the Martian Inspection Drone

The interest of science community towards planet Mars has progressively increased in past decades. Rovers are already doing an excellent job in exploring the Martian surface environment and showed that the Red Planet is not suited for life. However, there is a possibility of enabling human exploration by having astronauts take shelter in habitats located within lava tubes, which can provide protection against radiation and dust storms. These tubes are extremely hard to explore with rovers, thus a flying vehicle will be more suitable for such tasks. INGENUITY (Martian helicopter) had already demonstrated that it is possible to fly on Mars by doing small and simple manoeuvres. Based on NASA's design, this article will introduce the development of guidance, navigation, and control operations of a Martian Inspection Drone (MID) that will be capable of finding the lava tube and scan it in real time using a RealSense camera. Linux based system was chosen in the development process, which allow ROS catkin workspace to connect ArduPilot and Gazebo. The navigation is accomplished using a combination of an inertial measurement unit, a camera, and a laser rangefinder. The flight computer runs an optical flow algorithm for control and navigation purpose. Also, a convolutional neural network is used to perform lava tube entrance detection and inspection.

Use of airway pressure-based indices to detect high and low inspiratory effort during pressure support ventilation: a diagnostic accuracy study

BackgroundAssessment of the patient’s respiratory effort is essential during assisted ventilation. We aimed to evaluate the accuracy of airway pressure (Paw)-based indices to detect potential injurious inspiratory effort during pressure support (PS) ventilation.MethodsIn this prospective diagnostic accuracy study conducted in four ICUs in two academic hospitals, 28 adult acute respiratory failure patients undergoing PS ventilation were enrolled. A downward PS titration was conducted from 20 cmH2O to 2 cmH2O at a 2 cmH2O interval. By performing an end-expiratory airway occlusion maneuver, the negative Paw generated during the first 100 ms (P0.1) and the maximal negative swing of Paw (∆Pocc) were measured. After an end-inspiratory airway occlusion, Paw reached a plateau, and the magnitude of change in plateau from peak Paw was measured as pressure muscle index (PMI). Esophageal pressure was monitored and inspiratory muscle pressure (Pmus) and Pmus–time product per minute (PTPmus/min) were used as the reference standard for the patient’s effort. High and low effort was defined as Pmus > 10 and < 5 cmH2O, or PTPmus/min > 200 and < 50 cmH2O s min−1, respectively.ResultsA total of 246 levels of PS were tested. The low inspiratory effort was diagnosed in 145 (59.0%) and 136 (55.3%) PS levels using respective Pmus and PTPmus/min criterion. The receiver operating characteristic area of the three Paw-based indices by the respective two criteria ranged from 0.87 to 0.95, and balanced sensitivity (0.83–0.96), specificity (0.74–0.88), and positive (0.80–0.91) and negative predictive values (0.78–0.94) were obtained. The high effort was diagnosed in 34 (13.8%) and 17 (6.9%) support levels using Pmus and PTPmus/min criterion, respectively. High receiver operating characteristic areas of the three Paw-based indices by the two criteria were found (0.93–0.95). A high sensitivity (0.80–1.00) and negative predictive value (0.97–1.00) were found with a low positive predictive value (0.23–0.64).ConclusionsBy performing simple airway occlusion maneuvers, the Paw-based indices could be reliably used to detect low inspiratory efforts. Non-invasive and easily accessible characteristics support their potential bedside use for avoiding over-assistance. More evaluation of their performance is required in cohorts with high effort.

Evaluation of first ray instability using the double dorsiflexion test: A prospective observational case-controlled study

BackgroundFirst-Ray (FR) stability allows for foot propulsion in-stance, taking 60% weight. First-ray instability (FRI) is associated with middle column overload, synovitis, deformity and osteoarthritis. Clinical detection can still be challenging. We propose to develop a clinical test that helps identify FRI using two simple manual manoeuvres. Methods10 patients with unilateral FRI were recruited. Unaffected contralateral feet were used as controls. Stringent exclusion criteria were applied including hallux MTP pain, laxity, inflammatory arthropathy and collagen disorders. A Klauemeter directly measured the sagittal plane dorsal first metatarsal head translation of affected vs unaffected feet. Maximum passive proximal phalanx 1st MTP joint dorsiflexion was measured using a video capture and Tracker motion software analysis with and without applying a dorsal force at the 1st metatarsal head using a Newton meter. Proximal phalanx motion was compared in affected vs unaffected feet with and without dorsal metatarsal head force application and compared to direct measurements using the Klaumeter. P value of < 0.05 was considered significant. ResultsFRI feet had dorsal translation greater than 8 mm (median, 11.94; interquartile range [IQR], 10.23–13.81) vs 1.77 for unaffected control feet was (median, 1.77; interquartile range [IQR], 1.23–2.96) using the Klauemeter. The percentage reduction in 1st MTP joint dorsiflexion ROM when applying the double dorsiflexion test FRI (mean reduction of 67.98%) when compared to control feet (mean reduction of 28.44%)(P < 0.01). Receiver operating characteristic (ROC) analysis showed that a 50% reduction in dorsiflexion ROM of 1st MTPJ when performing the double dorsiflexion test achieved a specificity of 100% and sensitivity of 90% (AUC =0.990, 95%CI [0.958–1.000], P > 0.0001). ConclusionThe double dorsiflexion (DDF) is easy to perform with two relatively simple manual manoeuvres that avoids the need for complex instrumented and radiation-based assessment. Greater than 50% decrease in proximal phalanx motion has an over 90% sensitivity in identifying feet with FRI. Level of EvidenceThis was a prospective case-controlled study of consecutive cases of a level II evidence.

Video Ocular Counter-Roll (vOCR): Otolith-Ocular Function and Compensatory Effect of the Neck Following Vestibular Loss.

Assessment of recovery following vestibular loss has been limited by the lack of bedside measures in clinical settings. Here, we used the video ocular counter-roll (vOCR) test to study otolith-ocular function and compensatory effect of neck proprioception in patients at different stages of vestibular loss. Case-control study. Tertiary care center. Fifty-six subjects were recruited including patients with acute (9 ± 2 days [mean ± standard error of mean]), subacute (61 ± 11 days), and chronic (1009 ± 266 days) unilateral loss of vestibular function, as well as a group of healthy controls. We used a video-oculography method based on tracking the iris for vOCR measurement. To examine the effect of neck inputs, vOCR was recorded during two simple tilt maneuvers in all subjects while seated: 30°head-on-body tilt and 30°head-and-body tilt. The vOCR responses evolved at different stages following vestibular loss with improvement of the gains in the chronic stage. The deficit was more pronounced when the whole body was tilted (acute: 0.08 ± 0.01, subacute: 0.11 ± 0.01, chronic: 0.13 ± 0.02, healthy control: 0.18 ± 0.01), and the gain of vOCR improved when the head was tilted on the body (acute: 0.11 ± 0.01, subacute: 0.14 ± 0.01, chronic: 0.13 ± 0.02, healthy control: 0.17 ± 0.01). The time course of vOCR response was affected as well with reduced amplitude and slower response in the acute stage of vestibular loss. The vOCR test can be valuable as a clinical marker to measure vestibular recovery and compensatory effect of neck proprioception in patients at different stages following loss of vestibular function.

A Network approach to find poor orthostatic tolerance by simple tilt maneuvers.

The approach introduced by Network Physiology intends to find and quantify connectedness between close- and far related aspects of a person's Physiome. In this study I applied a Network-inspired analysis to a set of measurement data that had been assembled to detect prospective orthostatic intolerant subjects among people who were destined to go into Space for a two weeks mission. The advantage of this approach being that it is essentially model-free: no complex physiological model is required to interpret the data. This type of analysis is essentially applicable to many datasets where individuals must be found that "stand out from the crowd". The dataset consists of physiological variables measured in 22 participants (4f/18m; 12 prospective astronauts/cosmonauts, 10 healthy controls), in supine, + 30° and + 70° upright tilted positions. Steady state values of finger blood pressure and derived thereof: mean arterial pressure, heart rate, stroke volume, cardiac output, systemic vascular resistance; middle cerebral artery blood flow velocity and end-tidal pCO2 in tilted position were (%)-normalized for each participant to the supine position. This yielded averaged responses for each variable, with statistical spread. All variables i.e., the "average person's response" and a set of %-values defining each participant are presented as radar plots to make each ensemble transparent. Multivariate analysis for all values resulted in obvious dependencies and some unexpected ones. Most interesting is how individual participants maintained their blood pressure and brain blood flow. In fact, 13/22 participants had all normalized Δ-values (i.e., the deviation from the group average, normalized for the standard deviation), both for +30° and +70°, within the 95% range. The remaining group demonstrated miscellaneous response patterns, with one or more larger Δ-values, however of no consequence for orthostasis. The values from one prospective cosmonaut stood out as suspect. However, early morning standing blood pressure within 12h after return to Earth (without volume repletion) demonstrated no syncope. This study demonstrates an integrative way to model-free assess a large dataset, applying multivariate analysis and common sense derived from textbook physiology.

Streptococcus oralis infection of a ventriculoperitoneal shunt

Streptococcus oralis (S. oralis) belongs to the viridans group Streptococci (VGS) and is part of the normal flora of the human oral cavity, oropharynx, and nasopharynx. S. oralis meningitis is very rare and there are no reports of ventriculo-peritoneal shunt (VPS) infection caused by this bacterium. With this case report we aimed to describe the characteristics of such an extremely rare case and explore its clinical significance. A 10-year-old girl, with a history of metastatic cerebellar medulloblastoma treated with surgical resection followed by chemotherapy, radiotherapy and a VPS, presented with abdominal pain and a peri‑appendicular collection. As the pain worsened while on co-amoxiclav, she underwent laparoscopic exploration, drainage of purulent peritoneal fluid, externalization of her VPS, followed by appendicectomy. A diagnosis of appendicitis was excluded by the normal macroscopic and histological examination of the appendix, and a negative fluid culture result. Cerebrospinal fluid from the externalized VPS 9 days after shunt externalization grew S. oralis. She was treated with antibiotics, extended drainage with a ventricular drain and eventually rendered shunt-free. Our case illustrates an extremely rare infection secondary to the small scalp defect. Predisposing factors in our case included an externally-facing suture knot, the use of an adult valve in a small child, and previous radiotherapy. To the best of our knowledge this is the first case of VPS infection due to S. oralis reported worldwide so far. Neurosurgeons should be aware of the rare VPS infection causes and their predisposing factors, particularly the surgery-related and avoidable ones. Simple surgical maneuvers and choice of implantable shunt component can remarkably reduce morbidity in vulnerable pediatric patients.

Laparoscopic Excision of Large Wilms Tumor in Children: A Single-Center Experience from a Resource-Challenged Nation.

Background: In this study, we aim to review the outcomes of children with Wilms tumor (WT) operated through the minimally invasive surgery (MIS) approach at our center. We also intend to highlight essential surgical steps during laparoscopic excision of large WTs. Methods: This retrospective study included children with unilateral WT who had undergone resection for a period of 4 years, w.e.f. July 2013 to July 2017. Simple maneuvers such as tilting the table in different positions and use of blunt metallic cannula to lift the tumor to access the hilar vessels were used to dissect large WT. An extended lumbotomy incision was used for retrieval of tumor and lymph-node sampling. Results: Eleven patients (male:female = 7:4) of WT, all having stage III disease, had undergone laparoscopic tumor resection at our center during the study period. The median age at presentation was 36 months (range = 17 months-5 years) and the median preoperative tumor volume was 1140 (range = 936-1560) cm3. The average length of the lumbotomy incision was 6.3 (range = 5-8.2) cm. The median hospital stay was 6 (range = 5-10) days. Two children developed complications (port-site recurrence and grade III surgical site infection in one each) during the postoperative period. All cases are long-term survivors after a median follow-up of 86 (range = 56-104) months. Conclusion: This study highlights the feasibility and safety of the removal of large WT through the MIS approach. Problems due to large-sized tumors in children can be overcome by simple maneuvers. Also, adequate lymph node sampling is possible with a suitably placed extended lumbotomy incision for tumor removal.

603 Evaluation the First Ray Instability Using the Double Dorsiflexion Test: A Prospective Observational Case-Controlled Study

Abstract First-Ray (FR) stability allows for foot propulsion in-stance, taking 60% weight. First-ray instability (FRI) is associated with middle column overload, synovitis, deformity, and osteoarthritis. Clinical detection can still be challenging. We propose to develop a clinical test that helps identify FRI using two simple manual manoeuvres. 10 patients with unilateral FRI were recruited. Stringent exclusion criteria were applied including hallux MTP pain, laxity, inflammatory arthropathy. A Klauemeter directly measured the sagittal plane dorsal first metatarsal head translation of affected vs unaffected feet. Maximum passive proximal phalanx 1st MTP joint dorsiflexion was measured using Tracker motion software analysis with and without applying a dorsal force at the 1st metatarsal head using a Newton meter. P-value of &amp;lt;0.05 was considered significant. FRI feet had dorsal translation greater than 8mm (median, 11.94; interquartile range [IQR], 10.23–13.81) vs 1.77 for unaffected control feet was (median, 1.77; interquartile range [IQR], 1.23–2.96) using the Klauemeter. The percentage reduction in 1st MTP joint dorsiflexion ROM when applying the double dorsiflexion test FRI (mean reduction of 67.98%) when compared to control feet (mean reduction of 28.44%)(P&amp;lt;0.01). Receiver operating characteristic (ROC) analysis showed that a 50% reduction in dorsiflexion ROM of 1st MTPJ when performing the double dorsiflexion test achieved a specificity of 100% and sensitivity of 90% (AUC =0.990, 95%CI [0.958–1.000], P&amp;gt;0.0001). The double dorsiflexion (DDF) is easy to perform with manual manoeuvres that avoid complex instrumented and radiation-based assessment. A greater than 50% decrease in proximal phalanx motion has an over 90% sensitivity in identifying feet with FRI.

Buoyancy and hydrostatic balance in a West Indian Ocean coelacanth Latimeria chalumnae

BackgroundBuoyancy and balance are important parameters for slow-moving, low-metabolic, aquatic organisms. The extant coelacanths have among the lowest metabolic rates of any living vertebrate and can afford little energy to keep station. Previous observations on living coelacanths support the hypothesis that the coelacanth is neutrally buoyant and in close-to-perfect hydrostatic balance. However, precise measurements of buoyancy and balance at different depths have never been made. ResultsHere we show, using non-invasive imaging, that buoyancy of the coelacanth closely matches its depth distribution. We found that the lipid-filled fatty organ is well suited to support neutral buoyancy, and due to a close-to-perfect hydrostatic balance, simple maneuvers of fins can cause a considerable shift in torque around the pitch axis allowing the coelacanth to assume different body orientations with little physical effort.ConclusionsOur results demonstrate a close match between tissue composition, depth range and behavior, and our collection-based approach could be used to predict depth range of less well-studied coelacanth life stages as well as of deep sea fishes in general.

Valsalva Maneuver Decreases Liver and Spleen Stiffness Measured by Time-Harmonic Ultrasound Elastography

Ultrasound elastography quantitatively measures tissue stiffness and is widely used in clinical practice to diagnose various diseases including liver fibrosis and portal hypertension. The stiffness of soft organs has been shown to be sensitive to blood flow and pressure-related diseases such as portal hypertension. Because of the intricate coupling between tissue stiffness of abdominal organs and perfusion-related factors such as vascular stiffness or blood volume, simple breathing maneuvers have altered the results of liver elastography, while other organs such as the spleen are understudied. Therefore, we investigated the effect of a standardized Valsalva maneuver on liver stiffness and, for the first time, on spleen stiffness using time-harmonic elastography (THE). THE acquires full-field-of-view stiffness maps based on shear wave speed (SWS), covers deep tissues, and is potentially sensitive to SWS changes induced by altered abdominal pressure in the hepatosplenic system. SWS of the liver and the spleen was measured in 17 healthy volunteers under baseline conditions and during the Valsalva maneuver. With the Valsalva maneuver, SWS in the liver decreased by 2.2% (from a median of 1.36 m/s to 1.32 m/s; p = 0.021), while SWS in the spleen decreased by 5.2% (from a median of 1.63 m/s to 1.51 m/s; p = 0.00059). Furthermore, we observed that the decrease was more pronounced the higher the baseline SWS values were. In conclusion, the results confirm our hypothesis that the Valsalva maneuver decreases liver and spleen stiffness, showing that THE is sensitive to perfusion pressure-related changes in tissue stiffness. With its extensive organ coverage and high penetration depth, THE may facilitate translation of pressure-sensitive ultrasound elastography into clinical routine.

Body temperature and cardiovascular regulation in older adults during 8‐hour exposures to ambient conditions experienced indoors during extreme heat events: A randomized crossover trial

Most heat‐related deaths and hospitalizations occur in older adults, who spend the majority of their time in the home. However, recent studies aimed at improving our understanding of the physiological challenge posed by extreme heat events (EHE) have exposed participants to peak outdoor conditions, which differ markedly from those occurring indoors. In this randomized crossover trial (ClinicalTrials.gov identifier: NCT04348630), we assessed body temperature and cardiovascular responses in older adults exposed to a range of conditions commonly experienced indoors during EHE – from an air‐conditioned environment to a poorly insulated and ventilated domicile. We hypothesized that body core temperature and heart rate would be elevated in proportion to ambient temperature while mean arterial pressure would show the reverse response. We further surmised that cardiovascular adjustments to simple postural changes would be exacerbated at higher ambient temperatures.Fifteen older adults (5 women, 71 (SD 3) years, 25 (3) kg/m2) completed four 8‐hour exposures to 22°C (COOL), 26°C (TEMP), 31°C (WARM), and 36°C (HOT, each 45% relative humidity, &lt;0.3 m/s air flow). Participants were seated throughout, except for during hour 7 when they completed a cardiovascular test battery including two standing from supine tests. Rectal temperature was monitored continuously. Heart rate and arterial blood pressures were measured every hour. The heart rate and systolic pressure responses to standing were calculated as standing – supine values. Resting responses at the end of the 8‐hour exposure and during the standing tests were evaluated by comparing linear mixed‐effect model estimated marginal means between adjacent conditions.Rectal temperature was elevated by 0.2°C [95% CI: 0.1, 0.4] in TEMP (37.1 (0.3)°C) compared to COOL (36.9 (0.4)°C), 0.5°C [0.3, 0.6] in WARM (37.6 (0.2)°C) compared to TEMP, and 0.3°C [0.2, 0.3] in HOT (37.8 (0.2)°C) compared to WARM (all P≤0.005). Heart rate increased 2 beats/min [0, 4], 7 beats/min [4, 10] and 5 beats/min [2, 7] from COOL (59 (8) beats/min) to TEMP (61 (6) beats/min), TEMP to WARM (69 (9) beats/min) and WARM to HOT (74 (11) beats/min), respectively (all P&lt;0.001). Mean arterial pressure showed the reverse response, falling 7 mm Hg [2, 12] from COOL (101 (15) mm Hg) to TEMP (95 (11) mm Hg), 7 mm Hg [4, 9] from TEMP to WARM (88 (9) mm Hg) and 4 mm Hg from WARM to HOT (84 (10) mm Hg; all P≤0.02). While the change in heart rate from supine to standing did not differ between COOL and TEMP (P=0.68) or between WARM and HOT (P=0.46), it was 5 beats/min [1, 9] greater in WARM (14 (8) beats/min) compared to TEMP (10 [7] beats/min; P=0.006). The systolic response to standing did not differ between conditions (P=0.08).Body core temperature and cardiovascular responses in resting older adults were proportional to ambient temperature. We also show that the heart rate response when moving from supine to standing is exacerbated at ambient temperatures above 26°C. This study provides novel information on the physiological strain experienced indoors during EHE, both during rest and simple maneuvers consistent with activities of daily living.

Buoyancy and Hydrostatic Balance in The West Indian Coelacanth Latimeria chalumnae

Buoyancy and balance are important parameters for static or slow moving low‐metabolic aquatic organisms. The extant coelacanths, a single genus (Latimeria) consisting of two species living at moderate depths (100 – 400 m) in the Western Indian Ocean and off Indonesia and representing an ancient group of lobe finned fishes dating back to the early Devonian (410 Myr), have among the lowest metabolic rates of any living vertebrate, and thus would be predicted to expend precious little energy to maintain buoyancy and balance. Previous observations on living coelacanths support the hypothesis that the coelcanth is neutrally buoyant and is in close to perfect hydrostatic balance in any body posture. Likewise, point‐by‐point measurements of tissue composition have shown a generally high lipid content of coelacanth tissue supporting neutral buoyancy without a gas filled bladder as found in other sarcopterygians (lungs) and in many actinopterygians (swim bladder). However, precise measurements of buoyancy and hydrostatic balance at different depths have never been made in the coelacanth. Here we show using non‐invasive imaging that buoyancy of the coelacanth closely matches its depth distribution and a close‐to‐perfect balance can be used by the animal to change body posture with little effort. We found that the lipid filled “fatty organ” of the coelacanth is well adapted to support neutral buoyancy and simple maneuvers of fins can cause a considerable shift in torque around the pitch axis. This allows the coelacanth to assume and remain in any body posture like horizontal orientation, headstand or tail stand with little physical effort. Our results demonstrate a close match between tissue composition in the extant coelacanth, depth range and behavior (e.g. effortless vertical drift hunting with the electrosensitive rostral organ in close contact with the substrate). We anticipate our non‐invasive technique of mapping tissue components to be a starting point for more sophisticated models of buoyancy and hydrostatic balance in aquatic vertebrates in general. Specifically, we suggest the technique can be used on the few late term and juvenile coelacanth specimens in existence to predict the most likely habitat depth of the juvenile life stage which is currently unknown.

Design of a Low-Cost Air Bearing Testbed for Nano CMG Maneuvers

In this paper, a low-cost, miniature spacecraft attitude control simulator is presented for testing miniature actuators such as Nano Control Moment Gyroscopes (CMGs) for simple maneuvers. The experimental setup is composed by an attitude control system (ACS) that mainly consists of a four-CMG cluster in a pyramid configuration and a custom-made air bearing. The one-degree-of-freedom (DoF) air bearing is fabricated to reproduce the frictionless conditions of a nano-satellite in orbit. The ACS is made exclusively using low-cost commercial-off-the-shelf (COTS) components, whilst the air bearing is made using 3D-printed parts. Both hardware and software implementations are described in detail and the performance of the developed simulator is evaluated by two maneuver experiments. Despite the manufacturing imperfections, the ACS is capable of providing higher angular velocities than previously presented in the literature while following the theoretical or simulation data. The results indicate that it is possible to manufacture a low-cost, miniature actuator such as a CMG, using COTS components to demonstrate the operation of an agile nano-satellite. Any deviations from the theoretical values are addressed and several improvements are discussed to further enhance the performance of the air bearing testing platform.