76 research outputs found
Citizen Science Provides Valuable Data for Monitoring Global Night Sky Luminance
The skyglow produced by artificial lights at night is one of the most dramatic
anthropogenic modifications of Earth’s biosphere. The GLOBE at Night citizen
science project allows individual observers to quantify skyglow using star
maps showing different levels of light pollution. We show that aggregated
GLOBE at Night data depend strongly on artificial skyglow, and could be used
to track lighting changes worldwide. Naked eye time series can be expected to
be very stable, due to the slow pace of human eye evolution. The standard
deviation of an individual GLOBE at Night observation is found to be 1.2
stellar magnitudes. Zenith skyglow estimates from the ‘‘First World Atlas of
Artificial Night Sky Brightness’’ are tested using a subset of the GLOBE at
Night data. Although we find the World Atlas overestimates sky brightness in
the very center of large cities, its predictions for Milky Way visibility are
accurate
Uso de oócitos bovinos como citoplasma receptor na produção de embriões por transferência nuclear de célula somática interespécie (NTSCi) Use of bovine oocytes as recipient cytoplasm in the production of embryos through nuclear transfer of interspecies so
ABSTRACT Interspecies embryo clones have been produced by research groups with relative success in some species. Bovine oocytes matured in vitro and enucleated by micromanipulation were used in three experiments as recipeient cytoplasm in nuclear transfer of ovine, caprine and porcine fibroblasts. The fibroblasts were cultivated until the third passage before being frozen and used. The electrofusion was induced by an application of a 20V pulse during 45 ms. The activation was done with 5 mM ionomycin and subsequently 2 mM 6DMAP. NTSC bovine embryos, NTSCi caprine and ovine embryos were cultivated in SOF medium and NTSCi porcine embryos were cultivated in NCSU23 medium. The fusion rates of the reconstructed complexes with bovine cells did not differ from those observed with ovine cells (88.2%), caprine cells (74.1%) and porcine cells (79.4%). The cleavage rates in ovine (60.3%), caprine (68.4%) and porcine (57.1%) NTSCi groups did not differ from the control group NTSC bovine. The blastocyst rate observed in the group of NTSCi ovine embryos (10.3%) was similar to the group of NTSC bovine embryos (12.7%). In NTSCi caprine embryos, 5.3% of the embryos developed up to the blastocyst stage, while in the NTSCi porcine group there was no development up to the blastocyst stage. In conclusion, the bovine cytoplasm was able to support the embryo development in NTSCi up to the blastocyst stage using ovine and caprine fibroblasts as donor cells. Keywords: Embryo, Clones, Interspecies, Nuclear Transfer, In vitro. RESUMO Embriões clones interespécie vêm sendo produzidos por diferentes grupos de pesquisa, com relativo sucesso em algumas espécies. Oócitos bovinos maturados in vitro e enucleados por micromanipulação foram utilizados em três experimentos como citoplasma receptor na transferência nuclear de fibroblastos ovinos, caprinos e suínos. Os fibroblastos foram cultivados até a terceira passagem antes de serem congelados e utilizados. A eletrofusão foi induzida pela aplicação de um pulso de 20 V durante 45 ms. A ativação foi realizada com 5 mM de ionomicina e 2 mM de 6DMAP. Embriões NTSC bovinos, NTSCi caprinos e ovinos foram cultivados em meio SOF, e embriões NTSCi suínos foram cultivados em NCSU23. As taxas de fusão dos complexos reconstruídos com células bovinas não diferiram daquelas observadas com células ovinas (88,2%), caprinas (74,1%) e suínas (79,4%). As taxas de clivagem nos grupos NTSCi ovino (60,3%), caprino (68,4%) e suína (57,1%) não diferiram dos grupos controles NTSC bovino. A taxa de blastocisto observada nos embriões NTSCi ovinos (10,3%) foi semelhante à taxa observada no grupo NTSC bovino (12,7%). No grupo NTSCi caprino, 5,3% dos embriões chegaram ao estádio de blastocisto, enquanto que no grupo NTSCi suíno não houve desenvolvimento até o estádio de blastocisto. O citoplasma bovino foi capaz de suportar o desenvolvimento de embriões NTSCi até o estádio de blastocisto utilizando-se núcleo de fibroblatos ovinos e caprinos
Worldwide variations in artificial skyglow
Despite constituting a widespread and significant environmental change,
understanding of artificial nighttime skyglow is extremely limited. Until now,
published monitoring studies have been local or regional in scope, and
typically of short duration. In this first major international compilation of
monitoring data we answer several key questions about skyglow properties.
Skyglow is observed to vary over four orders of magnitude, a range hundreds of
times larger than was the case before artificial light. Nearly all of the
study sites were polluted by artificial light. A non-linear relationship is
observed between the sky brightness on clear and overcast nights, with a
change in behavior near the rural to urban landuse transition. Overcast skies
ranged from a third darker to almost 18 times brighter than clear. Clear sky
radiances estimated by the World Atlas of Artificial Night Sky Brightness were
found to be overestimated by ~25%; our dataset will play an important role in
the calibration and ground truthing of future skyglow models. Most of the
brightly lit sites darkened as the night progressed, typically by ~5% per
hour. The great variation in skyglow radiance observed from site-to-site and
with changing meteorological conditions underlines the need for a long-term
international monitoring program
An overview of the recent developments on fructooligosaccharide production and applications
Over the past years, many researchers have suggested
that deficiencies in the diet can lead to disease states
and that some diseases can be avoided through an adequate
intake of relevant dietary components. Recently, a great interest
in dietary modulation of the human gut has been registered.
Prebiotics, such as fructooligosaccharides (FOS), play a key
role in the improvement of gut microbiota balance and in
individual health. FOS are generally used as components of
functional foods, are generally regarded as safe (generally
recognized as safe status—from the Food and Drug Administration,
USA), and worth about 150€ per kilogram. Due to
their nutrition- and health-relevant properties, such as moderate
sweetness, low carcinogenicity, low calorimetric value,
and low glycemic index, FOS have been increasingly used
by the food industry. Conventionally, FOS are produced
through a two-stage process that requires an enzyme production
and purification step in order to proceed with the chemical
reaction itself. Several studies have been conducted on the
production of FOS, aiming its optimization toward the development
of more efficient production processes and their potential
as food ingredients. The improvement of FOS yield and
productivity can be achieved by the use of different fermentative
methods and different microbial sources of FOS producing
enzymes and the optimization of nutritional and
culture parameter; therefore, this review focuses on the latest
progresses in FOS research such as its production, functional
properties, and market data.Agencia de Inovacao (AdI)-Project BIOLIFE reference PRIME 03/347. Ana Dominguez acknowledges Fundacao para a Ciencia e a Tecnologia, Portugal, for her PhD grant reference SFRH/BD/23083/2005
A global agenda for advancing freshwater biodiversity research
Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.Peer reviewe
Ecological commonalities among pelagic fishes: comparison of freshwater ciscoes and marine herring and sprat
Systematic comparisons of the ecology between functionally similar fish species from freshwater and marine aquatic systems are surprisingly rare. Here, we discuss commonalities and differences in evolutionary history, population genetics, reproduction and life history, ecological interactions, behavioural ecology and physiological ecology of temperate and Arctic freshwater coregonids (vendace and ciscoes, Coregonus spp.) and marine clupeids (herring, Clupea harengus, and sprat, Sprattus sprattus). We further elucidate potential effects of climate warming on these groups of fish based on the ecological features of coregonids and clupeids documented in the previous parts of the review. These freshwater and marine fishes share a surprisingly high number of similarities. Both groups are relatively short-lived, pelagic planktivorous fishes. The genetic differentiation of local populations is weak and seems to be in part correlated to an astonishing variability of spawning times. The discrete thermal window of each species influences habitat use, diel vertical migrations and supposedly also life history variations. Complex life cycles and preference for cool or cold water make all species vulnerable to the effects of global warming. It is suggested that future research on the functional interdependence between spawning time, life history characteristics, thermal windows and genetic differentiation may profit from a systematic comparison of the patterns found in either coregonids or clupeids
Citizen science’s transformative impact on science, citizen empowerment and socio-political processes
Citizen science (CS) can foster transformative impact for science, citizen empowerment and socio-political processes. To unleash this impact, a clearer understanding of its current status and challenges for its development is needed. Using quantitative indicators developed in a collaborative stakeholder process, our study provides a comprehensive overview of the current status of CS in Germany, Austria and Switzerland. Our online survey with 340 responses focused on CS impact through (1) scientific practices, (2) participant learning and empowerment, and (3) socio-political processes. With regard to scientific impact, we found that data quality control is an established component of CS practice, while publication of CS data and results has not yet been achieved by all project coordinators (55%). Key benefits for citizen scientists were the experience of collective impact (“making a difference together with others”) as well as gaining new knowledge. For the citizen scientists’ learning outcomes, different forms of social learning, such as systematic feedback or personal mentoring, were essential. While the majority of respondents attributed an important value to CS for decision-making, only few were confident that CS data were indeed utilized as evidence by decision-makers. Based on these results, we recommend (1) that project coordinators and researchers strengthen scientific impact by fostering data management and publications, (2) that project coordinators and citizen scientists enhance participant impact by promoting social learning opportunities and (3) that project initiators and CS networks foster socio-political impact through early engagement with decision-makers and alignment with ongoing policy processes. In this way, CS can evolve its transformative impact
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