529 research outputs found
1.6 GHz Low-Power Cross-Correlator System Enabling Geostationary Earth Orbit Aperture Synthesis
We present a 64-channel cross-correlator system for space-borne synthetic aperture imaging. Two different types of ASICs were developed to fit into this system: An 8-channel comparator ASIC implemented in a 130 nm SiGe BiCMOS process technology performs A/D conversion, while a single 64-channel digital cross-correlator ASIC implemented in a 65 nm CMOS process performs the signal processing. The digital ASIC handles 2016 cross-correlations at up to 3.6 GS/s and has a power dissipation of only 0.13 mW/correlation/GHz at a supply voltage of 1 V. The comparator ASIC can handle sample rates of at least 4.5 GS/s with a power dissipation of 47 mW/channel or 1 GS/s with a power dissipation of 17 mW/channel. The assembled system consists of a single board measuring a mere 136 x 136 mm(2) and weighing only 135 g. The assembled system demonstrates crosstalk of 0.04% between neighboring channels and stability of 800 s. We provide ASIC and system-board measurement results that demonstrate that aperture synthesis can be a viable approach for Earth observation from a geostationary Earth orbit
Lithological controls of the Mg isotope composition of the Lena River across seasons and its impact on the annual isotope flux to the Arctic Ocean
Moderators of the disapproval of peer punishment
Recent studies have found disapproval of peer punishment of norm violations. This seems puzzling, given the potential benefits peer punishers contribute to the group. We suggest part of the answer is that peer punishers tend to come across as aggressive and as such may be viewed as more problematic than beneficial to have around. We used simple computer animations of geometric shapes to enact 15 precise variations of social sanctions against a norm violator. More than 1,800 subjects were recruited to watch an animation and judge the behavior and character of the animated agents. They also completed a trait aggression measure. Across the variations peer punishment was typically disapproved of, especially when severe or openly aggressive, and especially by subjects low on trait aggression. We conclude that there seems to be a social norm against peer punishment and that dislike of aggressiveness seems to be part of the reason why
Total and Trimester-Specific Gestational Weight Gain and Offspring Birth and Early Childhood Weight: A Prospective Cohort Study on Monozygotic Twin Mothers and Their Offspring
Peer reviewe
Improvement of radiological consequence estimation methodologies for NPP accidents in the ARGOS and RODOS decision support systems through consideration of contaminant physico-chemical forms
Costly Punishment in the Ultimatum Game Evokes Moral Concern, in Particular when Framed as Payoff Reduction
The ultimatum game is a common economic experiment in which some participants reject another’s unfair offer of how to split some money, even though it leaves them both worse off. This costly behavior can be seen as enforcement of a fairness norm and has been labeled “altruistic punishment”, suggesting that it is a moral thing to do. But is this behavior viewed as moral by participants? Is it viewed as punishment? And are the payoff consequences of the behavior sufficient to determine the answers to these questions? To investigate this we framed costly punishment in two different ways: either as rejection of an offer (the standard ultimatum game framing) or as reduction of payoff. In a series of paid and hypothetical experiments we found that moral concerns about costly punishment depended on the framing. Specifically, the reduction frame elicited more moral concern about, and less use of, costly punishment than did the rejection frame. Several implications are discussed
Asymmetric introgression reveals the genetic architecture of a plumage trait
Genome-wide variation in introgression rates across hybrid zones offers a powerful opportunity for studying population differentiation. One poorly understood pattern of introgression is the geographic displacement of a trait implicated in lineage divergence from genome-wide population boundaries. While difficult to interpret, this pattern can facilitate the dissection of trait genetic architecture because traits become uncoupled from their ancestral genomic background. We studied an example of trait displacement generated by the introgression of head plumage coloration from personata to alba subspecies of the white wagtail. A previous study of their hybrid zone in Siberia revealed that the geographic transition in this sexual signal that mediates assortative mating was offset from other traits and genetic markers. Here we show that head plumage is associated with two small genetic regions. Despite having a simple genetic architecture, head plumage inheritance is consistent with partial dominance and epistasis, which could contribute to its asymmetric introgression. Hybrid zones are windows into the evolutionary process. Semenov et al. find that the head plumage differences between white wagtail subspecies have a simple genetic basis involving two small genetic regions, in which partially dominant and epistatic interactions help to explain how this sexual signal has become decoupled from other plumage traits
Amyloid Deposition in Transplanted Human Pancreatic Islets: A Conceivable Cause of Their Long-Term Failure
Following the encouraging report of the Edmonton group, there was a rejuvenation of the islet transplantation field. After that, more pessimistic views spread when long-term results of the clinical outcome were published. A progressive loss of the β-cell function meant that almost all patients were back on insulin therapy after 5 years. More than 10 years ago, we demonstrated that amyloid deposits rapidly formed in human islets and in mouse islets transgenic for human IAPP when grafted into nude mice. It is, therefore, conceivable to consider amyloid formation as one potential candidate for the long-term failure. The present paper reviews attempts in our laboratories to elucidate the dynamics of and mechanisms behind the formation of amyloid in transplanted islets with special emphasis on the impact of long-term hyperglycemia
Internet-Based Vestibular Rehabilitation for Older Adults With Chronic Dizziness: A Randomized Controlled Trial in Primary Care
Purpose: Vestibular Rehabilitation (VR) is an effective intervention for dizziness due to vestibular dysfunction, but is seldom provided. We aimed to determine the effectiveness of internet-based VR for older adults experiencing dizziness in primary care. Methods: A single centre, single blind randomised controlled trial comparing an internet-based VR intervention with usual primary care was conducted with patients from 54 primary care practices in southern England (ISRCTN: 86912968). Patients aged 50 years and over with current dizziness exacerbated by head movements were included in the trial. Patients accessed an automated internet-based intervention that taught VR exercises and suggested cognitive behavioural management strategies. Dizziness was measured by the Vertigo Symptom Scale Short-Form (VSS-SF) at baseline, 3 and 6 months. The primary outcome was VSS-SF score at 6 months. Results: A total of 296 patients were randomized into the trial (66% female, median age 67). The VSS-SF was completed by 250 participants at 3 months (84%: 123 intervention (77%), 127 usual care (93%)) and 230 participants at 6 months (78%: 112 intervention (70%), 118 usual care (87%)). At 3 and 6 months dizziness symptoms were significantly lower in the internet-based VR group compared to usual care (2.75, 95% CI, 1.39 to 4.12; p<0.001 and 2.26, 95% CI, 0.39 to 4.12; p=0.018 respectively). Dizziness-related disability was also significantly lower in the internet-based VR condition, at 3 (6.15 95% CI, 2.81 to 9.49; p<0.001) and 6 month (5.58, 95% CI, 1.19 to 10.0; p=0.013). Conclusions: Internet-based VR improves dizziness and reduces dizziness-based disability in older primary care patients without requiring clinical support, and has potential for wide application in community settings
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