Applications to celestial mechanics

El Problema Restringit de Tres Cossos (Restricted Three Body Problem en anglés) ha sigut àmpliament estudiat i té múltiples aplicacions en astrodinàmica i mecànica celest. En aquest projecte s'estudien les òrbites periòdiques al voltant dels punts d'equilibri i les varietats invariants associades. S'explica de forma general com calcular aquestes òrbites i les seves varietats invariants per qualsevol dels tres punts d'equilibri alineats. A l'hora de fer l'anàlisi numèric ens centrem en el cas del punt L1 per òrbites periòdiques amb una consant de Jacobi entre C1 i C2, explicant tota la dinàmica intrínsica d'aquestes varietats i el comportament en variar el valor del paràmetre de massa i de la constant de Jacobi

Student perspective and lessons learned from participating in the European Rover Challenge 2021

The European Rover Challenge (ERC) is a competition where multiple teams from all around the world must face the technical, logistical, scientific and managerial difficulties of designing, building and operating a rover capable of performing a myriad of different tasks in a Mars analogue terrain (also known as Mars Yard). The competition, held in Kielce, Poland and organized by the Kielce University of Technology in collaboration with the European Space Foundation, regional governments, the European Space Agency, the Mars Society and other honorary patrons showcases each team’s creativity, innovation, drive and passion to an expecting audience, serves as an entry point to complex large-scale engineering projects for students from all backgrounds, supplying them with essential soft skills often overlooked during regular university education and connects like-minded individuals from different countries, encouraging international communication and collaboration in the aerospace industry. The authors of this paper participated in last year’s competition, ERC2021, and achieved 10th position. In this paper the insider perspective from first-time ERC participants will be discussed, including all the steps made to apply and qualify, the issues faced along the way, the lessons learned and the final experience of the on-site trials

A multi-project student space association

The aerospace sector has always been a challenge. The complex nature of the field requires for talented, skilful engineers. And while the university does great on the development of the theoretical background, it barely gets into the practical application. This is why embracing educational activities is critical to help students develop their technical and teamwork skills in the professional sector. UPC Space Program is an engineering student association based in the Terrassa campus of the Polytechnical University of Catalonia (Spain), and formed by 5 missions and 80 members. Each mission targets a field of interest in the space sector: rocketry, UAVs for space exploration, High Altitude Balloons, rovers and CubeSats. The sharing of the common spaces by such a number of people who are working on so many and diverse projects creates a vibrant and creative environment that incites learning. Our work is aligned with the current activities in the space sector. As the exploration of the terrestrial bodies of the Solar System highly benefits from the use of rovers, our Grass mission is focused on the development of planetary exploration rovers. After achieving 10th place in the European Rover Challenge 2021, the objective is to further upgrade the vehicle for the next edition. But currently, a new exploration focus is appearing as flying vehicles are entering the stage. In this context, our Aldora mission is based around a concept mission to Titan via an autonomous plane capable of deploying scientific probes. Obviously, space exploration is not possible without the presence of space transport vehicles. In this matter, Ares mission is focused on the development of High Power amateur rockets. Currently, Ares is developing a supersonic rocket set to participate in EUROC 2022 competition. But most of the payloads carried by rockets are satellites. In this field, the Horus mission aims to investigate and optimize the manufacture of a CubeSat, along with mission performance, to create a fully operational satellite, currently set to participate in the Europe to Space competition. Finally, there is yet another way to perform space science. Our Zephyros mission works in the development of High Altitude Balloons, also developing a set of experiments to test in near-space conditions. The next objective is to achieve the first student-developed zero pressure balloon in Spai

Reappraising the use of forearm rings for bat species

Altres ajuts: acords transformatius de la UABLong-term mark-recapture studies are essential for bat conservation. Over the last decades, millions of bats across Europe and America have been marked with forearm rings for this purpose. Although it is considered a cost-effective method compared to Passive Integrated Transponders (PIT) tags, direct injuries from using forearm rings have been reported since their very first use. Yet, their impact on bats' welfare has not been systematically evaluated and remains a highly controversial issue among the scientific community and policymakers. Here we assess the impact of forearm rings and PIT tags on the health of different bat species. We reviewed 12 years of the existing recapture data of free-ranging bats from NE Spain and evaluated the impact of both marking tools in a captive colony of Carollia perspicillata, by assessing the development of skin lesions and levels of cortisol metabolites in guano (CG) after marking. We report that 55.1 % (435/790) of the recaptured free-ranging bats with forearm rings presented skin lesions. All banded C. perspicillata (n = 22, 100 %) developed skin lesions, whereas none of the PIT-tagged (n = 21) presented lesions. Levels of CG were significantly higher after marking with forearm rings only for one group. Banded C. perspicillata exhibited discomfort-associated behaviours due to forearm rings. Under the "precautionary principle", we recommend the ban of forearm rings for all bat species until species-specific studies under controlled conditions are performed and approved by a legally constituted ethics committee. Consideration of other long-term marking tools is mandatory to align with global bat conservation strategies

Enhancing physicians’ radiology diagnostics of COVID-19’s effects on lung health by leveraging artificial intelligence

Introduction: This study aimed to develop an individualized artificial intelligence model to help radiologists assess the severity of COVID-19's effects on patients' lung health.Methods: Data was collected from medical records of 1103 patients diagnosed with COVID-19 using RT- qPCR between March and June 2020, in Hospital Madrid-Group (HM-Group, Spain). By using Convolutional Neural Networks, we determine the effects of COVID-19 in terms of lung area, opacities, and pulmonary air density. We then combine these variables with age and sex in a regression model to assess the severity of these conditions with respect to fatality risk (death or ICU).Results: Our model can predict high effect with an AUC of 0.736. Finally, we compare the performance of the model with respect to six physicians' diagnosis, and test for improvements on physicians' performance when using the prediction algorithm.Discussion: We find that the algorithm outperforms physicians (39.5% less error), and thus, physicians can significantly benefit from the information provided by the algorithm by reducing error by almost 30%

Enhancing physicians’ radiology diagnostics of COVID-19’s effects on lung health by leveraging artificial intelligence

Introduction: This study aimed to develop an individualized artificial intelligence model to help radiologists assess the severity of COVID-19’s effects on patients’ lung health.Methods: Data was collected from medical records of 1103 patients diagnosed with COVID-19 using RT- qPCR between March and June 2020, in Hospital Madrid-Group (HM-Group, Spain). By using Convolutional Neural Networks, we determine the effects of COVID-19 in terms of lung area, opacities, and pulmonary air density. We then combine these variables with age and sex in a regression model to assess the severity of these conditions with respect to fatality risk (death or ICU).Results: Our model can predict high effect with an AUC of 0.736. Finally, we compare the performance of the model with respect to six physicians’ diagnosis, and test for improvements on physicians’ performance when using the prediction algorithm.Discussion: We find that the algorithm outperforms physicians (39.5% less error), and thus, physicians can significantly benefit from the information provided by the algorithm by reducing error by almost 30%

Applications to celestial mechanics

El Problema Restringit de Tres Cossos (Restricted Three Body Problem en anglés) ha sigut àmpliament estudiat i té múltiples aplicacions en astrodinàmica i mecànica celest. En aquest projecte s'estudien les òrbites periòdiques al voltant dels punts d'equilibri i les varietats invariants associades. S'explica de forma general com calcular aquestes òrbites i les seves varietats invariants per qualsevol dels tres punts d'equilibri alineats. A l'hora de fer l'anàlisi numèric ens centrem en el cas del punt L1 per òrbites periòdiques amb una consant de Jacobi entre C1 i C2, explicant tota la dinàmica intrínsica d'aquestes varietats i el comportament en variar el valor del paràmetre de massa i de la constant de Jacobi

Applications to celestial mechanics

El Problema Restringit de Tres Cossos (Restricted Three Body Problem en anglés) ha sigut àmpliament estudiat i té múltiples aplicacions en astrodinàmica i mecànica celest. En aquest projecte s'estudien les òrbites periòdiques al voltant dels punts d'equilibri i les varietats invariants associades. S'explica de forma general com calcular aquestes òrbites i les seves varietats invariants per qualsevol dels tres punts d'equilibri alineats. A l'hora de fer l'anàlisi numèric ens centrem en el cas del punt L1 per òrbites periòdiques amb una consant de Jacobi entre C1 i C2, explicant tota la dinàmica intrínsica d'aquestes varietats i el comportament en variar el valor del paràmetre de massa i de la constant de Jacobi

Are sacred caves still safe havens for the endemic bats of Madagascar?

Despite conservation discourses in Madagascar increasingly emphasizing the role of customary institutions for wildlife management, we know relatively little about their effectiveness. Here, we used semi-structured interviews with 54 adults in eight villages to investigate whether sacred caves and taboos offer conservation benefits for cave-dwelling bats in and around Tsimanampetsotsa National Park, south-west Madagascar. Although some caves were described as sites of spiritual significance for the local communities, most interviewees (c. 76%) did not recognize their present-day sacred status. Similarly, only 22% of the interviewees recognized taboos inhibiting bat hunting and consumption. Legal protection of bats and caves through protected areas was often more widely acknowledged than customary regulations, although up to 30% of the interviewees reported consumption of bats within their communities. Guano extraction was often tolerated in sacred caves in exchange for economic compensation. This may benefit bat conservation by creating incentives for bat protection, although extraction is often performed through destructive and exploitative practices with little benefit for local communities. In view of these results our study questions the extent to which sacred sites, taboos and protected areas offer protection for bats in Madagascar. These results support previous studies documenting the erosion of customary institutions in Madagascar, including the loss of the spiritual values underpinning sacred sites. Given that many Malagasy bats are cave-dwelling species and that most depend on the customary protection of these sites, it is important to obtain a better understanding of the complex interactions between spiritual practices, taboos and protected areas in sustaining bat diversity

Human-bat interactions in rural Southwestern Madagascar through a biocultural lens

Human-bat interactions are common in rural areas across the tropics. Over 40 bat species occur in Madagascar, most of which are endemic. Forest loss is changing the distribution of bats throughout the island, with potential increases in both the abundance of synanthropic species and human-bat interactions. We set out to study knowledge of, interactions with, and attitudes towards bats in rural Madagascar, including reports of food and ethnomedicinal uses of bats, their cultural representations in folklore, and the existence of culturally enforced taboos in relation to them. We administered 108 surveys with open-and closed-ended questions with adults from the Tanala and Betsileo ethnic groups living around Ranomafana National Park. Most interviewees mentioned at least two types of bats. Over 10% of the interviewees had consumed bats and â20% used bat guano as a fertilizer. Around one-fifth recognized cultural taboos inhibiting bat hunting and consumption and most considered bats not to be dangerous. However, some informants mentioned that bats could carry diseases and complained about the bad smell and noise associated with bat roosts in houses and public buildings. Nearly 25% of the respondents could identify cultural representations of bats in local folklore. Malagasy rural communities interact closely with bats, but severely underestimate the diversity of bat species around them. Taken together, our results greatly increase the understanding of social-ecological complexities of human-bat relationships in rural Madagascar, offer possible pathways for biocultural approaches to conservation, and yield insights applicable to other communities coexisting with bats across the humid tropics