117 research outputs found
”Quantarctica": new standalone GIS package for Antarctic research, operation and education using open-source software
第4回極域科学シンポジウム横断セッション:[IP] 極域における多圏融合物理現象11月13日(水)国立極地研究所 3階 ラウン
Optical See-Through Head Mounted Display Direct Linear Transformation Calibration Robustness in the Presence of User Alignment Noise
Augmented Reality (AR) is a technique by which computer generated signals synthesize impressions that are made to coexist with the surrounding real world as perceived by the user. Human smell, taste, touch and hearing can all be augmented, but most commonly AR refers to the human vision being overlaid with information otherwise not readily available to the user. A correct calibration is important on an application level, ensuring that e.g. data labels are presented at correct locations, but also on a system level to enable display techniques such as stereoscopy to function properly [SOURCE]. Thus, vital to AR, calibration methodology is an important research area. While great achievements already have been made, there are some properties in current calibration methods for augmenting vision which do not translate from its traditional use in automated cameras calibration to its use with a human operator. This paper uses a Monte Carlo simulation of a standard direct linear transformation camera calibration to investigate how user introduced head orientation noise affects the parameter estimation during a calibration procedure of an optical see-through head mounted display
Nutrient-limited subarctic caves harbour more diverse and complex bacterial communities than their surface soil
Background: Subarctic regions are particularly vulnerable to climate change, yet little is known about nutrient
availability and biodiversity of their cave ecosystems. Such knowledge is crucial for predicting the vulnerability of
these ecosystems to consequences of climate change. Thus, to improve our understanding of life in these habitats,
we characterized environmental variables, as well as bacterial and invertebrate communities of six subarctic caves in
Northern Norway.
Results: Only a minuscule diversity of surface-adapted invertebrates were found in these caves. However, the bacte‑
rial communities in caves were compositionally diferent, more diverse and more complex than the nutrient-richer
surface soil. Cave soil microbiomes were less variable between caves than between surface communities in the same
area, suggesting that the stable cave environments with tougher conditions drive the uniform microbial communi‑
ties. We also observed only a small proportion of cave bacterial genera originating from the surface, indicating unique
cave-adapted microbial communities. Increased diversity within caves may stem from higher niche specialization and
levels of interdependencies for nutrient cycling among bacterial taxa in these oligotrophic environments.
Conclusions: Taken together this suggest that environmental changes, e.g., faster melting of snow as a result of
global warming that could alter nutrient infux, can have a detrimental impact on interactions and dependencies of
these complex communities. This comparative exploration of cave and surface microbiomes also lays the founda‑
tion to further investigate the long-term environmental variables that shape the biodiversity of these vulnerable
ecosystems.info:eu-repo/semantics/publishedVersio
Interaction Between Solid Copper Jets and Powerful Electrical Current Pulses
The interaction between a solid copper jet and an electric current pulse is studied. Coppe
Rapport fra 25. juni-utvalget: Evaluering av PST og politiet
Source at https://www.politiet.no/om-politiet/organisasjonen/sarorganene/politidirektoratet/
Genomic Analyses of Pre-European Conquest Human Remains from the Canary Islands Reveal Close Affinity to Modern North Africans
The origins and genetic affinity of the aboriginal inhabitants of the Canary Islands, commonly known as Guanches, are poorly understood. Though radiocarbon dates on archaeological remains such as charcoal, seeds, and domestic animal bones suggest that people have inhabited the islands since the 5th century BCE, it remains unclear how many times, and by whom, the islands were first settled. Previously published ancient DNA analyses of uniparental genetic markers have shown that the Guanches carried common North African Y chromosome markers (E-M81, E-M78, and J-M267) and mitochondrial lineages such as U6b, in addition to common Eurasian haplogroups. These results are in agreement with some linguistic, archaeological, and anthropological data indicating an origin from a North African Berber-like population. However, to date there are no published Guanche autosomal genomes to help elucidate and directly test this hypothesis. To resolve this, we generated the first genome-wide sequence data and mitochondrial genomes from eleven archaeological Guanche individuals originating from Gran Canaria and Tenerife. Five of the individuals (directly radiocarbon dated to a time transect spanning the 7th–11th centuries CE) yielded sufficient autosomal genome coverage (0.21× to 3.93×) for population genomic analysis. Our results show that the Guanches were genetically similar over time and that they display the greatest genetic affinity to extant Northwest Africans, strongly supporting the hypothesis of a Berber-like origin. We also estimate that the Guanches have contributed 16%–31% autosomal ancestry to modern Canary Islanders, here represented by two individuals from Gran Canaria
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Insights into human genetic variation and population history from 929 diverse genomes.
Genome sequences from diverse human groups are needed to understand the structure of genetic variation in our species and the history of, and relationships between, different populations. We present 929 high-coverage genome sequences from 54 diverse human populations, 26 of which are physically phased using linked-read sequencing. Analyses of these genomes reveal an excess of previously undocumented common genetic variation private to southern Africa, central Africa, Oceania, and the Americas, but an absence of such variants fixed between major geographical regions. We also find deep and gradual population separations within Africa, contrasting population size histories between hunter-gatherer and agriculturalist groups in the past 10,000 years, and a contrast between single Neanderthal but multiple Denisovan source populations contributing to present-day human populations.Wellcome grants 098051 and 206194, and S.A.M. and R.D. also by Wellcome grant 207492. A.B. and P.S. were supported by the Francis Crick Institute (FC001595) which receives its core funding from Cancer Research UK, the UK Medical Research Council and the Wellcome Trust. P.S. was also supported by the European Research Council (grant no. 852558) and the Wellcome Trust (217223/Z/19/Z). R.H. was supported by a Gates Cambridge scholarship. P.H. was supported by Estonian Research Council Grant PUT1036. D.R. is an Investigator of the Howard Hughes Medical Institute
Genomic insights into the conservation status of the world’s last remaining Sumatran rhinoceros populations
Highly endangered species like the Sumatran rhinoceros are at risk from inbreeding. Five historical and 16 modern genomes from across the species range show mutational load, but little evidence for local adaptation, suggesting that future inbreeding depression could be mitigated by assisted gene flow among populations. Small populations are often exposed to high inbreeding and mutational load that can increase the risk of extinction. The Sumatran rhinoceros was widespread in Southeast Asia, but is now restricted to small and isolated populations on Sumatra and Borneo, and most likely extinct on the Malay Peninsula. Here, we analyse 5 historical and 16 modern genomes from these populations to investigate the genomic consequences of the recent decline, such as increased inbreeding and mutational load. We find that the Malay Peninsula population experienced increased inbreeding shortly before extirpation, which possibly was accompanied by purging. The populations on Sumatra and Borneo instead show low inbreeding, but high mutational load. The currently small population sizes may thus in the near future lead to inbreeding depression. Moreover, we find little evidence for differences in local adaptation among populations, suggesting that future inbreeding depression could potentially be mitigated by assisted gene flow among populations
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