SunSat Design Competition 2015-2016 First Place Winner – Team Space Transport: Power Satellites Beamed Energy Bootstrapping

This International SunSat Design Competition first-place winner for 2016 describes a beamed energy transport system that will operate in Space above low earth orbit (LEO) as a way to move power satellite parts into high orbits. This design, entitled “Beamed Energy Bootstrapping,” makes use of small propulsion power satellites to provide the energy for space-based vehicles using electric arcjets. The proposal lays out a scheme to get the first propulsion power satellite in place without damage as it passes through the orbiting space junk below 2000 km. Click here to see the video: Space Transport for Power Satellites Beamed Energy Bootstrappin

SunSat Design Competition 2013-2014 Second Place Winner – Team Solar Maximum LLC: Sun-Synchronous Orbits

The orbital location of PowerSats plays a critical role in determining the mass of the solar power satellite (PowerSat) transmitter and the size of the rectenna on the Earth’s surface. These in turn play an important role in the cost of deploying the PowerSat, especially the cost of launching the PowerSat into orbit as the transmitter makes up a large part of the PowerSats mass. We will consider a new approach to PowerSat orbital positioning by considering a circular sun-synchronous orbit at 5,185.3 kilometers with an inclination of 142.1 degrees. Locating the PowerSat at this location offers several benefits and only one major drawback. The benefits include small transmitter, small ground rectenna, small minimum power levels, constant energy production and constant energy delivery. The one drawback in that this location is in the inner Van Allen radiation belt, which is a high radiation environment. Locating the PowerSat in the radiation belt is problematic as the radiation can damage the solar cells. However, the use of highly concentrated solar energy can potentially be used to heal the damaged solar cells, thereby providing a reasonable solution to the problem of radiation damage. Ideally the use of highly concentrated solar energy would be used in the design of the PowerSat anyway to reduce the mass to orbit requirements. By placing the PowerSat constellation in a medium Earth orbit (MEO) that is sun-synchronous the constellation can provide continuous power to specific sites on the ground. However, SPS in this orbit, which is the most intense region of the Earth’s Van Allen radiation belt, would require dramatic advances in radiation hardening for all systems. Solar arrays, in particular have been found to be susceptible to degradation due to exposure to radiation. Self-regeneration of solar cells using heat has already been demonstrated at the experimental stage and the high heat level available at 2,000 suns solar concentration should be sufficient to heal the cells. Concentrated solar energy can potentially reduce PowerSat energy production system mass by an order of magnitude (90%). This combined with a close orbit which can reduce transmitter mass by an order of magnitude (90%), will allow for the development and deployment of much smaller, more mass efficient PowerSats. In addition to these advantages the PowerSats will also have a much lower minimum power level which means that much smaller systems can be deployed incrementally rather than building massive PowerSats as has been proposed in the past. This paper and accompanying visualization will discuss the benefits of combining concentrated solar energy at 2,000 suns concentration with an MEO sun-synchronous orbit at 5,185.3 kilometers with an inclination of 142.1 degrees to achieve a low mass PowerSat and how to overcome the problem of a high radiation environment by taking advantage of the solar energy available to periodically heal the solar cells. Click here to see the video: Concentrated Solar in Sun-Synchronous Orbit - 2014 SunSat Design Competitio

SunSat Design Competition 2014-2015 Second Place Winner – Team SunFlower: Thermal Power Satellite

Space-based Solar Power has failed to be competitive on cost in spite of decades of study. A new approach appears to resolve the cost issue, undercutting coal and opening huge markets for low cost solar power from space. There are two parts to the problem. First is the cost of lifting parts to Geosynchronous Earth Orbit (GEO; second is the mass of parts that make up a power satellite. Our team is proposing a combination that makes use of Skylon to Low Earth Orbit (LEO), and a 15,000 ton payload ground powered electric propulsion from LEO to GEO. This strategy reduces the cost to under $200/kg, a 100-to-one reduction from the current cost for lifting communication satellites to GEO. Reaching these numbers requires a Skylon flight rate in excess of 10,000 per year. Even at$200/kg, the economics cannot tolerate more than 6.5 kg/kW for power satellites to undercut coal, e.g., 32,500 tons for a 5 GWe satellite. Low (20%) efficient photovoltaic (PV) systems are very difficult to reduce below 10 kg/kW. A 60% efficient thermal design has one third of the light intercepting area of a 20% efficient PV power satellite. Carnot considerations require a high temperature ratio between boilers and radiators. The thermal cycles considered in our approach use concentrating mirrors to direct sunlight into high-temperature boilers. The first working fluid proposed is potassium. After passing through a high temperature turbine, the condensing potassium heats a second working fluid (water or super critical CO2). Waste heat is channeled to low-temperature condensing radiators. Analysis found the radiators to be a relatively small part of the power satellite mass. Concentrators, boilers, turbines, generators, heat radiators and the transmitter massed close enough to 32,500 tons to merit further detailed investigation. The total, including rectenna, parts cost, labor and transportation, came to ~$2400/kW. Levelized cost of electricity from$2400 capital expense came to 3 cents per kWh, comfortably undercutting coal at 4 cents. Displacing coal on financial merits bypasses debates about CO2 buildup and climatology. If designs and economics can be verified, and assuming rapid expansion beyond the first dozen power satellites, the human race could be off fossil fuels as early as the mid-2030s. To achieve this goal, power satellites must cost less than $2400/kW, installed. It all depends on keeping the power satellite reasonably low in mass and transportation costs extremely low. Click here to see this team video: Team SunFlower - 2015 SunSat Design Competitio

Premating behavioral tactics of Columbian ground squirrels

In polygynous and polygynandrous mating systems males possess a variety of behavioral tactics that increase their access to reproductive females. In addition to overt combat or defending resources that attract mates, males use premating tactics that provide them with subsequent opportunities to copulate with receptive females. For Columbian ground squirrels, Urocitellus columbianus, we report that co-occupation of a burrow system by a reproductive male and a female on the night before the female exhibits diurnal estrus is an example of such a tactic. Our hypothesis was that nocturnal underground association results in successful consortships and therefore constitutes a mating tactic that is complementary to other mating behaviors exhibited during a female's estrus. Under this hypothesis appropriate predictions are that: males co-occupying a burrow system with a female at night should mate first with that female; males co-occupying a burrow system with a female overnight should sire more of her offspring than her subsequent mates; and the reproductive success of males co-occupying a burrow system with females should be higher than the reproductive success of mates that do not. To test our predictions we used a combination of field observations on nocturnal underground consortships (NUCs) and microsatellite DNA analyses of paternity. Males copulated with females during NUCs, as evidenced by inseminations. These males sired more offspring than males that did not participate in NUCs. Males ≥3 years old participated in more NUCs than sexually mature 2-year-old males. Our results supported the hypothesis that entrance into NUCs with a female before she exhibits estrus was a premating tactic that increased male reproductive success when exhibited in concert with other mating tactics such as territorial defens

The impact of chromatin modifiers on the timing of locus replication in mouse embryonic stem cells

A panel of mutant embryonic stem (ES) cell lines lacking important chromatin modifiers was used to dissect the relationship between chromatin structure and replication timing, revealing the importance of several chromatin modifiers for maintaining correct replication of satellite sequences in pluripotent ES cells

Investigação do efeito reparador do gel de ectoína em modelo de queima térmica

Due to the ability to create complexes of water molecules on the surface of the mucous membrane, ectoine is a promising compound for the treatment of burns. In male rats (n=30), 2 thermal burns were counteracted under counter-anesthesia, one of which was treated by topical application of the test drugs for 7 days, and the other served as a control. On the 8th day, skin samples in the area of the burn were taken for morphological examination. Histological sections were then scored by independent experts. The best histological picture of thermally damaged tissues was demonstrated by animals receiving ectoine. A less significant, but pronounced reparative effect was observed in histological samples of the actovegin group. The least significant reparative effect was demonstrated by contractubex. Ectoine improved the histological picture, improved repair and reduced the inflammatory response of the tissues and can be recommended for further preclinical studies as a treatment for burns.Debido a la capacidad de crear complejos de moléculas de agua en la superficie de la membrana mucosa, la ectoina es un compuesto prometedor para el tratamiento de las quemaduras. En ratas macho (n = 30), 2 quemaduras térmicas se contrarrestaron con contraestesia, una de las cuales se trató mediante la aplicación tópica de los fármacos de prueba durante 7 días, y la otra sirvió como control. En el octavo día, se tomaron muestras de piel en el área de la quemadura para un examen morfológico. Las secciones histológicas fueron calificadas por expertos independientes. El mejor cuadro histológico de los tejidos dañados térmicamente fue demostrado por los animales que recibieron ectoína. Se observó un efecto reparador menos significativo, pero pronunciado en muestras histológicas del grupo actovegin. El efecto reparador menos significativo fue demostrado por contractubex. Ectoine mejoró el cuadro histológico, mejoró la reparación y redujo la respuesta inflamatoria de los tejidos y puede recomendarse para estudios preclínicos adicionales como tratamiento para las quemaduras.Devido à capacidade de criar complexos de moléculas de água na superfície da membrana mucosa, a ectoína é um composto promissor para o tratamento de queimaduras. Em ratos machos (n = 30), duas queimaduras térmicas foram combatidas sob anestesia, uma das quais foi tratada por aplicação tópica das drogas de teste por 7 dias, e a outra serviu como controle. No oitavo dia, amostras de pele na área da queimadura foram retiradas para exame morfológico. As secções histológicas foram então classificadas por especialistas independentes. O melhor quadro histológico dos tecidos termicamente lesados foi demonstrado pelos animais que receberam ectoína. Um efeito reparador menos significativo, mas pronunciado, foi observado em amostras histológicas do grupo da actovegina. O efeito reparador menos significativo foi demonstrado pelo contratoubex. Ectoine melhorou o quadro histológico, melhorou o reparo e reduziu a resposta inflamatória dos tecidos e pode ser recomendado para estudos pré-clínicos adicionais como tratamento para queimaduras

COVID19 Disease Map, a computational knowledge repository of virus-host interaction mechanisms.

Funder: Bundesministerium für Bildung und ForschungFunder: Bundesministerium für Bildung und Forschung (BMBF)We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, bioinformaticians and computational biologists. The diagrams of the C19DMap, curated from the literature, are integrated with relevant interaction and text mining databases. We demonstrate the application of network analysis and modelling approaches by concrete examples to highlight new testable hypotheses. This framework helps to find signatures of SARS-CoV-2 predisposition, treatment response or prioritisation of drug candidates. Such an approach may help deal with new waves of COVID-19 or similar pandemics in the long-term perspective

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe