229 research outputs found

    Localizzazione naturale e ri-collocazione del valore

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    Tre circostanze circoscrivono il futuro degli approcci bioregionali o ‘territorialisti’. La prima è che le regioni naturali esistono quali spazi ecologici e sociali auto-somiglianti. La seconda è che i fenomeni energetici, climatici e dell’entropia fanno sì che il mondo delle necessità materiali umane debba essere dislocato malgrado le nostre aspirazioni. La terza circostanza è che le reti di informazioni che attualmente dominano l’economia globale sono meno sensibili ai limiti dell’entropia. Mentre i combustibili fossili hanno dislocato il valore locale, le reti informatiche vanno oltre, de-materializzandolo. I movimenti di localizzazione rappresentano le naturali strutture alternative per la ri-collocazione del valore.Three conditions circumscribe the future of bioregional or ‘territorialist’ approaches. First, natural regions do exist as self-similar ecological and cultural geographic spaces. Second, the facts of energy, climate, and entropy ensure that the world of physical human necessities must relocalize regardless of our wishes. Third, information networks now dominate the global economy and are less sensitive to entropic constraints. While fossil fuels have di-splaced local value, information networks go further by de-materializing value. Localization movements are natural alternative structures for the re-placement of value

    Effects of live-bait shrimp trawling on seagrass beds and fish bycatch in Tampa Bay, Florida

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    The use of live shrimp for bait in recreational fishing has resulted in a controversial fishery for shrimp in Florida. In this fishery, night collections are conducted over seagrass beds with roller beam trawls to capture live shrimp, primarily pink shrimp, Penaeus duorarum. These shrimp are culled from the catch on sorting tables and placed in onboard aerated “live” wells. Beds of turtlegrass, Thalassia testudinum, a species that has highest growth rates and biomass during summer and lowest during the winter (Fonseca et al., 1996) are predominant areas for live-bait shrimp trawling (Tabb and Kenny, 1969). Our study objectives were 1) to determine effects of a roller beam trawl on turtlegrass biomass and morphometrics during intensive (up to 18 trawls over a turtlegrass bed), short-term (3-hour duration) use and 2) to examine the mortality of bycatch finfish following capture by a trawl

    Heart rate variability and cortisol responses during attentional and working memory tasks in naval cadets

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    The aim of the paper was to study the relationship between heart rate variability (HRV) and cortisol release during cognitive challenging tasks. Forty-nine male naval cadets from the Royal Norwegian Naval Academy were administered computerised versions of attentional and working memory tests. The results from this study support the hypothesis of a negative correlation between HRV and cortisol secretion during cognitive tasks. Confirmation of the hypothesis with the low HRV group scoring higher on cortisol only during performance of cognitive tasks and recovery was also found. Furthermore, a replication of the previous findings of a negative association between cortisol levels and performance were supported when using uncorrected comparisons. None of the correlations survived Bonferonin corrections. The findings are discussed in relation to factors increasing HRV, thus improving tolerance to cognitive stress in onboard environments

    Robert Dworak Correspondence

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    Entry is a handwritten letter on College of the Atlantic stationery from Dworak\u27s wife, the library director

    Pregnancy in teenagers diagnosed with type 1 diabetes mellitus in childhood: a national population-based e-cohort study

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    The aim of this study was to describe the characteristics and outcomes of pregnancies in a national cohort of teenage (<20 years) and young adult women (≥20 years) with and without childhood-onset (<15 years) type 1 diabetes. We hypothesised that, owing to poor glycaemic control during the teenage years, pregnancy outcomes would be poorer in teenage mothers with type 1 diabetes than young adult mothers with type 1 diabetes and mothers without diabetes

    The pseudo-mitochondrial genome influences mistakes in heteroplasmy interpretation

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    BACKGROUND: Nuclear mitochondrial pseudogenes (numts) are a potential source of contamination during mitochondrial DNA PCR amplification. This possibility warrants careful experimental design and cautious interpretation of heteroplasmic results. RESULTS: Here we report the cloning and sequencing of numts loci, amplified from human tissue and rho-zero (ρ(0)) cells (control) with primers known to amplify the mitochondrial genome. This paper is the first to fully sequence 46 paralogous nuclear DNA fragments that represent the entire mitochondrial genome. This is a surprisingly small number due primarily to the primer sets used in this study, because prior to this, BLAST searches have suggested that nuclear DNA harbors between 400 to 1,500 paralogous mitochondrial DNA fragments. Our results indicate that multiple numts were amplified simultaneously with the mitochondrial genome and increased the load of pseudogene signal in PCR reactions. Further, the entire mitochondrial genome was represented by multiple copies of paralogous nuclear sequences. CONCLUSION: These findings suggest that mitochondrial genome disease-associated biomarkers must be rigorously authenticated to preclude any affiliation with paralogous nuclear pseudogenes. Importantly, the common perception that mitochondrial template "swamps" numts loci precluding detectable amplification, depends on the region of the mitochondrial genome targeted by the PCR reaction and the number of pseudogene loci that may co-amplify. Cloning and relevant sequencing data will facilitate the correct interpretation. This is the first complete, wet-lab characterization of numts that represent the entire mitochondrial genome

    Impact of CIR Storms on Thermosphere Density Variability during the Solar Minimum of 2008

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    The solar minimum of 2008 was exceptionally quiet, with sunspot numbers at their lowest in 75 years. During this unique solar minimum epoch, however, solar wind high - speed streams emanating from near-equatorial coronal holes occurred frequently and were the primary contributor to the recurrent geomagnetic activity at Earth. These conditions enabled the isolation of forcing by geomagnetic activity on the preconditioned solar minimum state of the upper atmosphere caused by Corotating Interaction Regions (CIRs). Thermosphere density observations around 400 km from the CHAMP satellite are used to study the thermosphere density response to solar wind high - speed streams/CIRs. Superposed epoch results show that thermosphere density responds to high - speed streams globally, and the density at 400 km changes by 75% on average. The relative changes of neutral density are comparable at different latitudes, although its variability is largest at high latitudes. In addition, the response of thermosphere density to high - speed streams is larger at night than in daytime, indicating the preconditioning effect of the thermosphere response to storms. Finally, the thermosphere density variations at the periods of 9 and 13.5 days associated with CIRs are linked to the spatial distribution of low - middle latitude coronal holes on the basis of the EUVI observations from the STEREO.Comment: Solar Physics, accepted, April 2010, and the final version of this paper will appear in the website of Solar Physics soon

    Normal levels of p27Xic1 are necessary for somite segmentation and determining pronephric organ size

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    The Xenopus laevis cyclin dependent kinase inhibitor p27Xic1 has been shown to be involved in exit from the cell cycle and differentiation of cells into a quiescent state in the nervous system, muscle tissue, heart and retina. We show that p27Xic1 is expressed in the developing kidney in the nephrostomal regions. Using over-expression and morpholino oligonucleotide (MO) knock-down approaches we show normal levels of p27Xic1 regulate pronephros organ size by regulating cell cycle exit. Knock-down of p27Xic1 expression using a MO prevented myogenesis, as previously reported; an effect that subsequently inhibits pronephrogenesis. Furthermore, we show that normal levels of p27Xic1 are required for somite segmentation also through its cell cycle control function. Finally, we provide evidence to suggest correct paraxial mesoderm segmentation is not necessary for pronephric induction in the intermediate mesoderm. These results indicate novel developmental roles for p27Xic1, and reveal its differentiation function is not universally utilised in all developing tissues

    Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe

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    The Extragalactic Background Light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ~10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts (GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of gamma-ray flux attenuation by the EBL. We place upper limits on the gamma-ray opacity of the Universe at various energies and redshifts, and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the "baseline" model of Stecker et al. (2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A. Reimer, L.C. Reye
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