Underwater Multi-Node Radio Communication Solutions for Planetary Exploration

The exploration of the presumably life harboring subsurface ocean of Europa will provide scientists with extensive new knowledge in the search for extraterrestrial life. A highly miniaturized payload is required to penetrate a narrow passage through the thick ice crust covering Europa's surface. Underwater wireless communications may be the most viable means of communication for such exploratory missions, accounting for size and weight restrictions. This presents a challenge to achieve satisfactory data rates and a range that permits autonomous underwater vehicles (AUVs) to communicate within their region of operation, as well as with a surface lander or orbiter. This work presents thorough prototype experimentation on an underwater communication system established between several nodes using RF signals. During an eight-week internship experience at NASA's Ames Research Center in September-October 2014, our team developed a Europa exploration mission concept, built representative hardware, and carried out tests to assess the feasibility of key aspects of the concept. Experiments demonstrating the viability of RF communication underwater comprised inspecting the effect of depth and horizontal distance on signal strength as well as the optimum positioning of antennas. To test the system's performance, two submersibles were designed and built. A commercially available remotely operated vehicle (ROV) was also modified and used as a main communication node. The two submersibles were wirelessly connected and accommodated sensors capable of characterizing water properties and equipped with 2.4 GHz, 1 mW transceivers to communicate the measured data. The communication procedure is that the main communication node requests the collected data from the two submersibles when in range and receives it instantly through RF. This work models what may take place during an actual mission to Europa. The developed mission concept involved a hybrid communication system consisting of acoustic and RF signals to enhance the capability of the nodes to communicate over greater distances. The AUVs will need to avoid obstacles and maneuver around to collect data based on predefined algorithms. Thus, they will be provided with two positioning systems; the inertial navigation system, backed with an acoustic positioning system to mitigate drift. The AUVs divide the ocean into planes and explore along circular paths increasing in diameter with depth. Moreover, they make use of miniaturized sensors to map the surrounding environment. In this paper, the ROV and the submersibles are described, along with sections explaining the mechanism of communication and the testing procedures conducted to yield results

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Climate Change Impacts on Surface Water Availability & Management of Jordan's Zarqa River Basin Using Soil and Water Assessment Tool (SWAT).

Zarqa River Basin (ZRB) is among Jordan's most important surface water basins, hosting the country's major cities and industry, and providing water for agricultural production within the basin and beyond. ZRB's surface runoff dilutes the treated wastewater of Khirbat As-Samra plant, mainly discharged by Greater Amman's and Zarqa's wastewater, before reaching King Talal Dam and further downstream covering up irrigation water demands of the Jordan Valley. Due to deforestation, intensive agriculture and overgrazing large areas of ZRB became vulnerable to soil erosion and thus land degradation - whereas the eroded sediments of the basin eventually accumulate in King Talal Reservoir and consequently decrease the impoundment's storage capacity. On top of this, the changing climate affects both quantity and the occurrence pattern of rainfall potentially speeding up land degradation and water storage loss of the King Talal Reservoir. A hydrological model was set-up to better understand the spatial pattern of surface water affected by various Soil and Water Conservation interventions within the basin and thus to reflect the landscape's response to 1) actual, as well as 2) future climatic conditions of different rainfall and temperature chaning scenarios; using different Representative Concentration Pathways (RCPs) from the highest available resolution data of the Global Circulation Models (GCMs). This contributes to the assessment future surface water availability - to increase preparedness for the predicted climatic changes and to support the development of mitigation strategies align with the Jordanian water sector management plans

A case of de Garengeot hernia: the feasibility of laparoscopic transabdominal preperitoneal hernia repair

Introduction: de Garengeot hernia is described as the presence of an appendix in a femoral hernia. This rare hernia usually presents with both diagnostic and therapeutic dilemmas. Presentation of case: We report a case of a 59 year-old woman with a one-year history of a right irreducible femoral hernia. She underwent diagnostic laparoscopy with an intraoperative diagnosis of de Garengeot hernia. This was followed by a laparoscopic transabdominal preperitoneal (TAPP) approach for hernia repair. Discussion: The long-standing presentation of de Garengeot hernia is seldomly reported in literature. There has been no standard approach of treatment for de Garengeot hernias described, possibly due to the rarity of this condition. The unusual presentation of the hernia prompted us to undergo a diagnostic laparoscopy first, during which the appendix was seen incarcerated in a femoral hernia sac. We were easily able to proceed for a laparoscopic TAPP approach for hernia repair without the need for conversion to an open repair. Conclusion: We were able to obtain an accurate diagnosis of an appendix within a long-standing irreducible femoral hernia through diagnostic laparoscopy followed by transabdominal preperitoneal (TAPP) approach for hernia repair. We would like to underline the usefulness of laparoscopy as a valuable tool in the diagnosis and treatment of this unusual presentation of groin hernias

A single left renal vein draining into the common iliac vein

Several variations of the anatomy of the left renal vein have been reported. Rare variants are frequently overlooked in the preoperative assessment but can lead to complications during surgery. We describe a kidney donor with a rare anomaly of a single main left renal vein draining into the left common iliac vein