113 research outputs found
National Park Service nonnative plant control in the Indiana Dunes National Lakeshore
Invasive plants have become a growing threat to plant diversity and hydrology in the Indiana Dunes National Lakeshore. Invasive plants compete with native plants for nutrients and sunlight, and certain invasive species have been known to completely take over certain areas of wetlands, nearly destroying entire ecosystems. The Dunes Lakeshore contains over 1,400 plants species and is one of the top ten most diverse national parks in the United States. The mission statement of the National Park Service is to âpreserve for the educational, inspirational, and recreational use of the public certain portions of the Indiana Dunes.â In order to properly maintain this unique habitat for future generations, a variety of techniques have been implemented to reduce the growth and germination of many nonnative plants in high quality areas such as Cowles Bog, West Beach, and Tolleston Dunes. We focused on depleting the seed bank of invasive plants by targeting certain species such as garlic mustard, Dameâs Rocket, and Crown Vetch before they seeded. Backpack sprayers, brush cutters and loppers were used to kill invasive plants within the park and GPS was used to monitor our progress
zkRelay: Facilitating Sidechains using zkSNARK-based Chain-Relays
We facilitate trusted cross-blockchain state proofs by implementing a chain-relay that validates block headers from proof-of-work blockchains. While current approaches require proof sizes linear to the amount of blocks the state was built on, trusted intermediaries, or economic assumptions, we propose the utilization of off-chain computations through zkSNARKs to provide a cryptographically secure and highly scalable sidechain mechanism. Multiple block headers are included in batches and verified off-chain, while preserving light client support. Only the validity of the off-chain computation is verified on-chain, creating a sidechain mechanism that requires constant verification costs and releases the target ledger from processing and storing every single block header of the source blockchain. We provide a prototypical implementation that facilitates the verification of 504 Bitcoin headers in a single proof on Ethereum using the ZoKrates framework. Hereby, the verification costs are reduced by a factor of 187 compared to current approaches such as BTC Relay
Non-thermal" Effects on the Blood-Brain Barrier in Fischer rats by exposure to microwaves
Effect of 915 MHz electromagnetic fields (EMF) on the blood brain-barrier (BBB) permeability has been studied in Fischer 344 rats of both sexes. Male and female Fischer 344 rats were exposed in a Transverse Electromagnetic Transmission line chamber to microwaves of 915 MHz as continuous wave (CW) and pulse-modulated with different pulse power and at various time intervals. The CW-pulse power varied from 0.001W to 10 W and the exposure time from 2 min. to 960 min. In each experiment we randomly placed 4 rats in excited and 4 control rats in non-excited TEM-cells respectively. The rats were not anaesthetised during the exposure. The rats were exposed to 915 MHz microwaves, either continuous wave (CW) or pulse modulated at 4,8,16 or 217 Hz with 0.57 ms pulse width, or pulse modulated at 50 Hz with 6.6 ms pulse width as well as from a real GSM-900 telephone. All animals were sacrificed by perfusion-fixation of the brains under chloralhydrate anaesthesia after the exposure. The brains were then perfused, first with saline for 3-4 minutes, and then with 4% formaldehyde for 5-6 minutes. Whole coronal sections of the brains were dehydrated and embedded in paraffin and sectioned at 5 Όm. The degree of albumin leakage was demonstrated immune-histo-chemically and classified in order of increased number of albumin extravasations by a rank number: 0 - 0.5 - 1.0 - 1.5 - 2 - 3. Pathological albumin leakage was judged as albumin extravasations equal to or larger than 1. The frequency of pathological rats in all control groups was about 17%. Among rats exposed to pulse modulated microwaves the ratio of pathological rats was 170/481(0.35±0.03) and among rats exposed to continuous wave exposure (CW) it was 74/149 (0.50±0.07). These results are both highly significantly different to their corresponding controls (p<0.0001). The rats were exposed to SAR various values: 0.2; 2; (20-40); (100-500); (1000-3000) mW/kg. In the 217 Hz modulated group (GSM simulated) we found the most increased ratio of albumin extravasations OR= 4 at 0.2 mW/kg. But no significant increased ratio at SAR 2000 mW/kg. The response curve of OR versus log(SAR) had the shape of a bathtub, with a minimum at a100 mW/kg. A similar curve was recorded for OR versus Specific Absorbed Energy (SAE Joule / kg) with a minimum at 100 J/kg. Similar response curves were recorded for the various modulation frequencies 4; 8; 16; 50 Hz. We found no pronounced difference between the various modulation frequencies other than the effect of CW exposure seems to be more effective than pulse modulated exposure in opening the BBB at high SAR values 100-2000 mW/kg. Conclusion: The opening of the BBB is most effective at SAR values in the range of 0.1-0.5 mW.kg-1 and less effective in the range of 50-500 mW.kg-1. In this low SAR range thermal effects are unlikely. Thus there seems to be a non-thermal mechanism involved triggering the opening of the BBB
A Response to the United Nations CITES Blockchain Challenge: Incremental and Integrative PoA-based Permit Exchange
The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) negotiated and administered by the United Nations Environment Programme (UNEP) regulates the international trade of endangered species and derived products through a permit-based system. Currently, the permit process is paper-based and hence highly prone to manipulations and errors. Being aware of blockchains' potential, the CITES Secretariat defined a challenge to determine whether a blockchain-based system can address the aforementioned issues and serve as a secure, efficient, and affordable permit processing system.
In this paper, we respond to the CITES Blockchain Challenge. First, we analyze the permit process and discuss how blockchain systems can improve that process in a way traditional systems cannot. Building on these results, we design a blockchain-based system that enables secure, manipulation resistant permit validation, produces an immutable record of processed permits, and is in compliance with the CITES agreement. To evaluate this design, we developed a proof-of-concept implementation compatible with the paper-based permit process and deployed it to a Proof-of-Authority-based blockchain network. This allows incremental adoption and integration with the existing process, thereby increasing acceptance and addressing affordability. Finally, we describe how a blockchain- based system could disruptively improve the established permit process by enforcing quotas and tracking provenance
Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phones.
The possible risks of radio-frequency electromagnetic fields for the human body is a growing concern for our society. We have previously shown that weak pulsed microwaves give rise to a significant leakage of albumin through the blood-brain barrier. In this study we investigated whether a pathologic leakage across the blood-brain barrier might be combined with damage to the neurons. Three groups each of eight rats were exposed for 2 hr to Global System for Mobile Communications (GSM) mobile phone electromagnetic fields of different strengths. We found highly significant (p< 0.002) evidence for neuronal damage in the cortex, hippocampus, and basal ganglia in the brains of exposed rats
Trauma, Memory and Religion
How can we screen trauma? This question might lead the perception of documentary films about atrocities in the 20th and 21st centuries, like S21 THE KHMER ROUGE KILLING MACHINE (Rithy Panh, CAMB/FR 2003) about Cambodia, THE LOOK OF SILENCE (Joshua Oppenheimer, ID/DK 2014) about Indonesia or DAS RADIKAL BĂSE (Stefan Ruzowitzky, AT 2013) about Nazi-Europe. A concern that may emerge as we watch films on atrocities is whether these artistic representations perhaps guide the public away from what âreally happenedâ. There certainly is a huge gap between, on the one hand, the immediate experience of the event that lies behind the interpretative screening and, on the other hand, watching the directorâs material while neither being a part nor ever having been part of the event. Yet often filmic representations are not intended to show what happened; instead they present case studies to be explored in the present. Often the films contain an inherent critique of genocidal violence and present humanistic perspectives on obedience. Mostly, these films underline the humanity of the victims, seeking to give names, faces and biographies so that they are much more than just numbers. What appears on the screen therefore challenges the audience with a moral question: what would you do
Mörka Neuron och Mobiltelefoner : Dedicerad till en 90-Ärig man, Arne Brun i Lund
Med denna svenska översikt av vĂ„ra egna och andra forskares observationer av mörka neuron vid mikrovĂ„gs exponering frĂ„n mobiltelefoner, som lite senkommet tillĂ€gnas Arne Brun pĂ„ hans 90 Ă„rs-dag, vill vi att hans insatser blir uppmĂ€rksammade och inte faller i glömska.Kring 2000 millennium skiftet pĂ„gick ett intensivt arbete i Lund med att sammanfatta och bekrĂ€fta effekterna av exponering med GSM-900 MHz mikrovĂ„gor pĂ„ blod-hjĂ€rna barriĂ€ren och hjĂ€rnans neuroner. Leif G. Salford, Arne Brun och medarbetare presenterade Ă„r 2003 i tidskriften Environmental Health Perspectives resultaten frĂ„n en undersökning av skador pĂ„ nervcellerna i rĂ„tthjĂ€rna efter exponering för mikrovĂ„gor frĂ„n GSM Mobiltelefoner. Kontroller och testdjur visade alla tecken pĂ„ nĂ€rvao av albumin i hypotalamus, vilket Ă„r normalt och indikerar att albumin infĂ€rgningen av BBB lĂ€ckaget ocksĂ„ fungerar. CresylviolettfĂ€rgningen avslöjade förekomst av spridda och grupperade mörka nervceller, som ofta var skrumpna och mörkt homogent fĂ€rgade utan urskiljbara interna cellstrukturer. NĂ„gra av dessa mörka nervceller var ocksĂ„ albuminpositiva eller visade cytoplasmatiska mikrovakuoler som indikerar en aktiv patologisk process. Ă
r 2008 presenterades resultaten av ytterligare undersökningar av blod-hjĂ€rn barriĂ€rens permeabilitet och nervcellsskador i rĂ„tthjĂ€rnan efter en Ă„terhĂ€mtningstid pĂ„ antingen 14 och 28 dagar efter 2 timmas exponering för mikrovĂ„gor frĂ„n GSM-mobiltelefoner i 900 MHz-bandet. Efter 14 dagars Ă„terhĂ€mtningstid observerades albumin-lĂ€ckage i BBB och albumin upptag i neuroner. Mörka neuron observerades endast hos rĂ„ttor som exponerats med det lĂ€gsta SAR-vĂ€rdet, 0,12 mW/kg. Efter 28 dagars Ă„terhĂ€mtnings period observerades lĂ€ckage av albumin endast hos rĂ„ttor som exponerats med det högsta SAR-vĂ€rdet, 100 mW/kg. DĂ€remot observerades efter 28 dagar förekomst av mörka neuron i rĂ„tthjĂ€rnor hos alla grupperna vilket korrelerade vĂ€l med neuronernas albumin upptag.I studien observeras neuro-patologiska förĂ€ndringar redan vid SAR-vĂ€rden sĂ„ lĂ„ga som 0,12 mW/kg vilket överensstĂ€mmer med vĂ„ra tidigare resultat. Speciellt iögonfallande Ă€r att det högsta albumin upptaget i neuroner observeras vid den lĂ€gsta SAR nivĂ„n pĂ„ 0,12 mW/kg. Frekvensen hos förekomsten av mörka nervceller ökade, jĂ€mfört med kontrollerna bĂ„de efter 14 och 28 dagars Ă„terhĂ€mtning, men var endast signifikant vid 28 dagar efter exponering. Inga signifikanta tecken pĂ„ förekomsten av mörka neuron observerades emellertid efter 7 dagars Ă„terhĂ€mtning.I en Fransk studie redovisad av Poulletier de Gannes och medarbetare 2009 exponerades enbart huvudet hos 16 st. Fischer 344-rĂ„ttor (14 veckor gamla) för GSM-900 under 2 timmar vid SAR vĂ€rden 0,14 och 2,0 W/kg. Fjorton alternatvt 50 dagar efter GSM-900 exponeringen kunde varken BBB-lĂ€ckage eller förekomst av mörka nervceller upptĂ€ckas i rĂ„tt hjĂ€rnorna. Deras resultat indikerar att det föreligger en vĂ€sentlig skillnad i resultaten vid helkropp exponering jĂ€mfört med exponering av endast huvudet.Ă
r 2015 presenterades en studie, stödd av Nationella Vetenskaps Akademin i Kina (NSFC), avseende albumin-lÀckage i blod-hjÀrnbarriÀren efter exponering med kontinuerliga mikrovÄgor pÄ 900 MHz med SARvÀrden mellan 0,016 (hela kroppen) och 2 W/kg (lokalt i huvudet). Hos rÄttor som exponerats under 28 dagar observerades cellulÀrt ödem och neuronal cellorganell degeneration hos rÄttorna. Dessutom observerades med immun-fÀrgning BBB-lÀckage av albumin i hippocampus och cortex. Efter exponering för 900 MHz mikrovÄgor under 14 respektive 28 dagar hade serum albumin diffunderat in i neuropilen mellan cellkropparna, som omger neuronerna. Upptag av Albumin i hippocampus neuron hos rÄttor exponerade under 28 dagar, visar förekomst av mörka neuron. Deras resultat Àr i linje med Lunda-resultaten som publicerades 2003 och 2008
Interferometric observations of the Mira star o Ceti with the VLTI/VINCI instrument in the near-infrared
We present K-band commissioning observations of the Mira star prototype o Cet
obtained at the ESO Very Large Telescope Interferometer (VLTI) with the VINCI
instrument and two siderostats. The observations were carried out between 2001
October and December, in 2002 January and December, and in 2003 January.
Rosseland angular radii are derived from the measured visibilities by fitting
theoretical visibility functions obtained from center-to-limb intensity
variations (CLVs) of Mira star models (Bessel et al. 1996, Hofmann et al. 1998,
Tej et al. 2003). Using the derived Rosseland angular radii and the SEDs
reconstructed from available photometric and spectrophotometric data, we find
effective temperatures ranging from T_eff=3192 +/- 200 K at phase phi=0.13 to
2918 +/- 183 K at phi=0.26. Comparison of these Rosseland radii, effective
temperatures, and the shape of the observed visibility functions with model
predictions suggests that o Cet is a fundamental mode pulsator. Furthermore, we
investigated the variation of visibility function and diameter with phase. The
Rosseland angular diameter of o Cet increased from 28.9 +/- 0.3 mas
(corresponding to a Rosseland radius of 332 +/- 38 R_sun for a distance of
D=107 +/- 12 pc) at phi=0.13 to 34.9 +/- 0.4 mas (402 +/- 46 R_sun) at phi=0.4.
The error of the Rosseland linear radius almost entirely results from the error
of the parallax, since the error of the angular diameter is only approximately
1 %.Comment: 12 pages, 8 figures, accepted for publication in Astronomy &
Astrophysic
Protein Evolution by Molecular Tinkering: Diversification of the Nuclear Receptor Superfamily from a Ligand-Dependent Ancestor
Phylogenetic reconstruction of the structure and function of the ancestor of the nuclear receptor protein family reveals how functional diversity evolves by subtle tinkering with an ancestral template
Benchmarking whole exome sequencing in the German Network for Personalized Medicine
Introduction
Whole Exome Sequencing (WES) has emerged as an efficient tool in clinical cancer diagnostics to broaden the scope from panel-based diagnostics to screening of all genes and enabling robust determination of complex biomarkers in a single analysis.
Methods
To assess concordance, six formalin-fixed paraffin-embedded (FFPE) tissue specimens and four commercial reference standards were analyzed by WES as matched tumor-normal DNA at 21 NGS centers in Germany, each employing local wet-lab and bioinformatics investigating somatic and germline variants, copy-number alteration (CNA), and different complex biomarkers. Somatic variant calling was performed in 494 diagnostically relevant cancer genes. In addition, all raw data were re-analyzed with a central bioinformatic pipeline to separate wet- and dry-lab variability.
Results
The mean positive percentage agreement (PPA) of somatic variant calling was 76% and positive predictive value (PPV) 89% compared a consensus list of variants found by at least five centers. Variant filtering was identified as the main cause for divergent variant calls. Adjusting filter criteria and re-analysis increased the PPA to 88% for all and 97% for clinically relevant variants. CNA calls were concordant for 82% of genomic regions. Calls of homologous recombination deficiency (HRD), tumor mutational burden (TMB), and microsatellite instability (MSI) status were concordant for 94%, 93%, and 93% respectively. Variability of CNAs and complex biomarkers did not increase considerably using the central pipeline and was hence attributed to wet-lab differences.
Conclusion
Continuous optimization of bioinformatic workflows and participating in round robin tests are recommend
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