768 research outputs found
Barbara Lüthi: Invading bodies. Medizin und Immigration in den USA 1880–1920 (= Studien zur historischen Sozialwissenschaft, Bd. 33), Frankfurt am Main:: Campus Verlag, 2009, 397 S.
Comparison of the epifaunal assemblage of an invasive and native macroalga
The rapid spread of introduced seaweeds is of essential concern, as they can have a deleterious
impact on coastal native seaweed and seagrass communities. However, non-indigenous species
can generate mixed responses when introduced to native assemblages, and increase habitat
complexity, depending on the spatial and ecological context. By taking advantage of the cooccurrence
of the native Ulva seaweeds and the non-native Agarophyton vermiculophyllum in
the Clonakilty estuary (Cork, Ireland) we aim to assess the differences of the epifaunal
community of the native and invasive macroalgal species and how epifaunal biodiversity may
be affected by the invasive. In four locations over four sampling occasions, a total of 253
quadrants of algae and epifaunal biomass were sampled. The Ulva dominated sections mainly
contained macroalgae with tubular morphotypes and some sporadic patches of laminar Ulva
rigida. The average algal biomass of both species was similar, however, the biomass of the red
seaweed was highly variable throughout the seasons. The native algal canopy hosted up to four
times more epifaunal biomass compared to the invasive rhodophyte. Moreover, the epifaunal
community of both canopies differed substantially, whereas deposit-feeding organisms had a
higher abundance in Ulva spp. canopies and the carnivorous crab, Carcinus maenas, was much
more abundant in A. vermiculophyllum samples. The native green macroalgae hosted more
invertebrate taxa, however no difference in biodiversity was found. Increased predation on
deposit-feeders and grazers, as well as, the structural and chemical resistance of A.
vermiculophyllum against grazing and overgrowth by epiphytes may reduce the trophic transfer
from primary production toward higher trophic levels.As introduções de espécies exóticas ocorrem já há vários séculos, de forma
intencional para ganho comercial ou involuntariamente, maioritariamente por transporte
marĂtimo como passageiros escondidos em águas de lastro ou agarrados ao casco do navio. A
rápida dispersĂŁo de algas nĂŁo-indĂgenas Ă© uma preocupação básica, já que podem ter impactos
nocivos nas comunidades algas e ervas marinhas costeiras indĂgenas e sĂŁo, juntamente com as
alterações climáticas, um dos fatores de stress mais significativos dos ecossistemas de hoje.
Estes impactos incluem a modificação da estrutura da comunidade da fauna, redução de
biodiversidade e alteração das dinâmicas de nutrientes estuarinas, que podem, em última
instância, acelerar a mudança de macrófitas de crescimento lento para macroalgas efémeras,
aumentando o risco de afloramentos de macroalgas. No entanto, as espĂ©cies nĂŁo-indĂgenas
podem gerar respostas mistas quando introduzidas em agrupamentos nativos, e aumentar a
complexidade do habitat, dependendo do contexto espacial e ecolĂłgico. Os factores de stress
antropogĂ©nicos como o aumento dos nĂveis de nutrientes podem intensificar a magnitude de
tais eventos e aumentar a sua frequência. A referida eutrofização aparente de sistemas costeiros
pode fomentar as invasões de macrófitas, assim como a sua resistência a grazing o que aumenta
ainda mais a probabilidade de afloramentos de macroalgas. Duas espĂ©cies indĂgenas de forma
laminar (Ulva rigida e Ulva gigantea) e duas espĂ©cies indĂgenas de forma tubular (Ulva
prolifera e Ulva compressa) do gĂ©nero Ulva bem como a rodĂłfita nĂŁo-indĂgena
A.vermiculophyllum foram identificadas no estuário de Clonakilty (Condado de Cork, Irlanda)
e estão a formar canópias distintas próximas umas das outras. A identificação de efeitos
positivos ou negativos de uma espĂ©cie nĂŁo-indĂgena em ecossistemas estuarinos e a forma
como é controlada teria implicações notáveis nas estratégias de gestão de espécies invasivas
fundacionais. Os vários impactos ecológicos na diversidade da epifauna e a utilização de
nutrientes precisam de ser avaliados, especialmente no contexto do sobre-enriquecimento de
nutrientes antropogénico local e a mudança global para reconhecer e recomendar uma
estratĂ©gia apropriada (activa ou passiva). Ao tirar proveito da co-ocorrĂŞncia de algas indĂgenas
e nĂŁo-indĂgenas neste estuário, tivemos como objectivos: (i) a comparação de padrões espaciais
e temporais na estrutura de comunidades de epifauna em ambas as algas; (ii) caracterizar o seu papel na formação de habitats de ambas as espécies e as suas implicações em diferentes taxa
da fauna; (iii) explorar implicações ecológicas para diferentes guildas alimentares e discutir o
impacto em cascadas tróficas; e (iv) a avaliação da biodiversidade da epifauna e a riqueza das
espécies de macroalgas.(…
A Verified and Compositional Translation of LTL to Deterministic Rabin Automata
We present a formalisation of the unified translation approach from linear temporal logic (LTL) to omega-automata from [Javier Esparza et al., 2018]. This approach decomposes LTL formulas into "simple" languages and allows a clear separation of concerns: first, we formalise the purely logical result yielding this decomposition; second, we develop a generic, executable, and expressive automata library providing necessary operations on automata to re-combine the "simple" languages; third, we instantiate this generic theory to obtain a construction for deterministic Rabin automata (DRA). We extract from this particular instantiation an executable tool translating LTL to DRAs. To the best of our knowledge this is the first verified translation of LTL to DRAs that is proven to be double-exponential in the worst case which asymptotically matches the known lower bound
Estimating inert gas bubbling from simple SCUBA diving parameters
Inert gas bubbles frequently occur in SCUBA divers' vascular systems, eventually leading to decompression accidents. Only in professional settings, dive profiles can be adjusted on individual basis depending on bubble grades detected through ultrasonography. A total of 342 open-circuit air dives following sports diving profiles were assessed using echocardiography. Subsequently, (Eftedal-Brubakk) bubble grades were correlated with dive and individual parameters. Post-dive cardiac bubbles were observed in 47% of all dives and bubble grades were significantly correlated with depth (r=0.46), air consumption (r=0.41), age (r=0.25), dive time (r=0.23), decompression diving (r=0.19), surface time (r=- 0.12). Eftedal-Brubakk categorical bubble grades for sports diving with compressed air can be approximated by bubble grade = (age*50-1 - surface time*150-1+maximum depth*45-1+air consumption*4500-1)2 (units in years, hours, meter, and bar*liter; R2=0.31). Thus, simple dive and individual parameters allow reasonable estimation of especially relevant medium to higher bubble grades for information on relevant decompression stress after ascent. Echo bubble grade 0 is overestimated by the formula derived. However, echo might fail to detect minor bubbling only. The categorical prediction of individual decompression stress with simple bio and dive data should be evaluated further to be developed towards dive computer included automatic ex-post information for decision-making on individual safety measures.info:eu-repo/semantics/publishedVersio
A PEST-like element in FREQUENCY determines the length of the circadian period in Neurospora crassa
FREQUENCY (FRQ) is a crucial element of the circadian clock in Neurospora crassa. In the course of a circadian day FRQ is successively phosphorylated and degraded. Here we report that two PEST-like elements in FRQ, PEST-1 and PEST-2, are phosphorylated in vitro by recombinant CK-1a and CK-1b, two newly identified Neurospora homologs of casein kinase 1ε. CK-1a is localized in the cytosol and the nuclei of Neurospora and it is in a complex with FRQ in vivo. Deletion of PEST-1 results in hypophosphorylation of FRQ and causes significantly increased protein stability. A strain harboring the mutant frqΔPEST-1 gene shows no rhythmic conidiation. Despite the lack of overt rhythmicity, frqΔPEST-1 RNA and FRQΔPEST-1 protein are rhythmically expressed and oscillate in constant darkness with a circadian period of 28 h. Thus, by deletion of PEST-1 the circadian period is lengthened and overt rhythmicity is dissociated from molecular oscillations of clock components
A PEST-like element in FREQUENCY determines the length of the circadian period in Neurospora crassa
Association of systemic inflammation with shock severity, 30-day mortality, and therapy response in patients with cardiogenic shock
Background: Mortality in cardiogenic shock (CS) remains high even when mechanical circulatory support (MCS) restores adequate circulation. To detect a potential contribution of systemic inflammation to shock severity, this study determined associations between C-reactive protein (CRP) concentrations and outcomes in patients with CS. Methods: Unselected, consecutive patients with CS and CRP measurements treated at a single large cardiovascular center between 2009 and 2019 were analyzed. Adjusted regression models were fitted to evaluate the association of CRP with shock severity, 30-day in-hospital mortality and treatment response to MCS. Results: The analysis included 1116 patients [median age: 70 (IQR 58–79) years, 795 (71.3%) male, lactate 4.6 (IQR 2.2–9.5) mmol/l, CRP 17 (IQR 5–71) mg/l]. The cause of CS was acute myocardial infarction in 530 (48%) patients, 648 (58%) patients presented with cardiac arrest. Plasma CRP concentrations were equally distributed across shock severities (SCAI stage B–E). Higher CRP concentrations were associated with 30-day in-hospital mortality (8% relative risk increase per 50 mg/l increase in CRP, range 3–13%; p < 0.001), even after adjustment for CS severity and other potential confounders. Higher CRP concentrations were only associated with higher mortality in patients not treated with MCS [hazard ratio (HR) for CRP > median 1.50; 95%-CI 1.21–1.86; p < 0.001], but not in those treated with MCS (HR for CRP > median 0.92; 95%-CI 0.67–1.26; p = 0.59; p-interaction = 0.01). Conclusion: Elevated CRP concentrations are associated with increased 30-day in-hospital mortality in unselected patients with cardiogenic shock. The use of mechanical circulatory support attenuates this association
Against all odds: a tale of marine range expansion with maintenance of extremely high genetic diversity
The displacement of species from equatorial latitudes to temperate locations following the increase in sea surface temperatures is among the significant reported consequences of climate change. Shifts in the distributional ranges of species result in fish communities tropicalisation, i.e., high latitude colonisations by typically low latitude distribution species. These movements create new interactions between species and new trophic assemblages. The Senegal seabream, Diplodus bellottii, may be used as a model to understand the population genetics of these invasions. In the last decades, this species has undergone an outstanding range expansion from its African area of origin to the Atlantic coast of the Iberian Peninsula, where now occurs abundantly. Mitochondrial and nuclear markers revealed a striking high haplotypic nucleotide and genetic diversity values, along with significant population differentiation throughout the present-day geographical range of the Senegal seabream. These results are not consistent with the central-marginal hypothesis, nor with the expectations of a leptokurtic distribution of individuals, as D. bellottii seems to be able to retain exceptional levels of diversity in marginal and recently colonised areas. We discuss possible causes for hyperdiversity and lack of geographical structure and subsequent implications for fisheries.Portuguese Foundation for Science and Technology: UID/MAR/04292/2019/ UID/Multi/04326/2019info:eu-repo/semantics/publishedVersio
Understanding Counterexamples for Relational Properties with DIbugger
Software verification is a tedious process that involves the analysis of multiple failed verification
attempts, and adjustments of the program or specification. This is especially the case for complex
requirements, e.g., regarding security or fairness, when one needs to compare multiple related runs
of the same software. Verification tools often provide counterexamples consisting of program inputs
when a proof attempt fails, however it is often not clear why the reported counterexample leads to
a violation of the checked property. In this paper, we enhance this aspect of the software
verification process by providing \emph{DIbugger}, a tool for analyzing counterexamples of relational
properties, allowing the user to debug multiple related programs simultaneously
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