Recent high-energy marine events in the sediments of the Lagoa de Óbidos and Martinhal (Portugal): Recognition, age and likely causes

© 2012 Author(s) - This work is distributed under the Creative Commons Attribution 3.0 License.This article has been made available through the Brunel Open Access Publishing Fund.A key issue in coastal hazards research is the need to distinguish sediments deposited by past extreme storms from those of past tsunamis. This study contributes to this aim by investigating patterns of sedimentation associated with extreme coastal flood events, in particular, within the Lagoa de Óbidos (Portugal). The recent stratigraphy of this coastal lagoon was studied using a wide range of techniques including visual description, grain-size analysis, digital and x-ray photography, magnetic susceptibility and geochemical analysis. The sequence was dated by 14C, 210Pb and Optically Stimulated Luminescence. Results disclose a distinctive coarser sedimentary unit, within the top of the sequence studied, and shown in quartz sand by the enrichment of elements with marine affinity (e.g., Ca and Na) and carbonates. The unit fines upwards and inland, thins inland and presents a sharp erosive basal contact. A noticeable post-event change in the sedimentary pattern was observed. The likely agent of sedimentation is discussed here and the conceivable association with the Great Lisbon tsunami of AD 1755 is debated, while a comparison is attempted with a possibly synchronous deposit from a tsunami in Martinhal (Algarve, Portugal). The possibility of a storm origin is also discussed in the context of the storminess of the western Portuguese coast and the North Atlantic Oscillation. This study highlights certain characteristics of the sedimentology of the deposits that may have a value in the recognition of extreme marine inundation signatures elsewhere in the world.This article is made available through the Brunel Open Access Publishing Fund

Recent avulsion history of Sefidrud, south west of the Caspian Sea

The Sefidrud, a river flowing into south west Caspian Sea, is prone to avulsion. Previous studies of the river delta support the idea that several major avulsions have occurred during the past few thousand years. During the most recent major avulsion, a 23 km shift occurred along the coast. However, in literature the timing of the event is subject to uncertainty and therefore the causes of the avulsion remain unclear. Lying in the most populated area in Iran explains the importance to investigate the Sefidrud river avulsion. In this study, an 11 m-long sequence was obtained from an area where the river splits off into an old and a new distributary, and where a large pre-avulsion wetland had developed. Palaeo-environmental studies including sedimentology, macro-remain, and palynology were performed to detect changes in environment. Five radiocarbon dates were obtained to determine the avulsion age. In parallel an analysis of historical maps around the timing of the supposed avulsion and for more recent times provided a complementary way of refining the avulsion age. The results from this novel multidisciplinary study show that the last major avulsion occurred at a date after the early1800s and before 1929, during a period of rapid water level fall. Hence this is several centuries more recent than so far suggested. Studying aerial photographs, this research confirms the occurrence of minor avulsion between 1955 and 2014 where the avulsion point is around 2 Km from the coast line, and during a period of sea level fall. The results of this study also suggest that beyond the immediate effects on society and agriculture, avulsion increases the rate of coastal erosion near the abandoned distributary, as sediments are temporarily sequestered on the floodplain and causes intensive erosion. Avulsion has also major impact on coastal lagoons and inland wetlands by river diverting into the lagoons and wetlands

Features of phytoplankton community in the southern Caspian Sea, a decade after the invasion of Mnemiopsis leidyi

Phytoplankton study has become more significant in the Caspian Sea due to the occurrence of ecological events such as algal blooms and the introduction of the invader species(Ctenophore, Mnemiopsis leidyi). A seasonal study was conducted to investigate the features of phytoplankton community one decade after this invasion in the Iranian coast of Caspian Sea during 2009-2010. According to the results, 195 species in eight phyla of phytoplanktons were identified. In spring, Bacillariophyta and Pyrrophyta were the dominant phyla with 40 and 29% of total abundance, respectively. In summer and winter the dominant phyla were made by Cyanophyta (92%) and Bacillariophyta (94%), respectively. The Bacillariophyta (57%) and Cyanophyta (28%) were the first and second dominant phyla in autumn . It seems that the ctenophore invasion into the Caspian Sea (due to the changes in nutrient levels and decline of phytoplankton grazers) and human's destructive activities play an effective role on phytoplankton community during the period. These changes were mainly accompanied with appearance of new and harmful species (with the ability of severe bloom making) and consequently, displacement of native species in this semi-enclosed ecosystem

Membrane diffusion- and capillary blood volume measurements are not useful as screening tools for pulmonary arterial hypertension in systemic sclerosis: a case control study

<p>Abstract</p> <p>Background</p> <p>There is no optimal screening tool for the assessment of pulmonary arterial hypertension (PAH) in patients with systemic sclerosis (SSc). A decreasing transfer factor of the lung for CO (TLCO) is associated with the development of PAH in SSc. TLCO can be partitioned into the diffusion of the alveolar capillary membrane (Dm) and the capillary blood volume (Vc). The use of the partitioned diffusion to detect PAH in SSc is not well established yet. This study evaluates whether Dm and Vc could be candidates for further study of the use for screening for PAH in SSc.</p> <p>Methods</p> <p>Eleven SSc patients with PAH (SScPAH+), 13 SSc patients without PAH (SScPAH-) and 10 healthy control subjects were included. Pulmonary function testing took place at diagnosis of PAH. TLCO was partitioned according to Roughton and Forster. As pulmonary fibrosis in SSc influences values of the (partitioned) TLCO, these were adjusted for fibrosis score as assessed on HRCT.</p> <p>Results</p> <p>TLCO as percentage of predicted (%) was lower in SScPAH+ than in SScPAH- (41 ± 7% <it>vs</it>. 63 ± 12%, p < 0.0001, respectively). Dm% in SScPAH+ was decreased as compared with SScPAH- (22 ± 6% <it>vs</it>. 39 ± 12%, p < 0.0001, respectively), also after adjustment for total fibrosis score (before adjustment: B = 17.5, 95% CI 9.0–25.9, p = < 0.0001; after adjustment: B = 14.3, 95% CI 6.0–21.7, p = 0.008). No difference was found in Vc%. There were no correlations between pulmonary hemodynamic parameters and Dm% in the PAH groups.</p> <p>Conclusion</p> <p>SScPAH+ patients have lower Dm% than SScPAH- patients. There are no correlations between Dm% and hemodynamic parameters of PAH in SScPAH+. These findings do not support further study of the role of partitioning TLCO in the diagnostic work- up for PAH in SSc.</p

A new approach to counting fossil and modern pollen grains: The orderly count

Palynology, the study of pollen and spores, plays a crucial role in various scientific disciplines, including earth sciences (paleovegetation and paleoclimatology), botany, allergy, archaeology, forensic sciencs and cosmetics. This study delves into the critical question in fossil pollen analysis studies: the minimum count of pollen grains required for accurate estimation of vegetation composition. Various statistical methods have been proposed over the years to address this question. Our research introduces an alternative technique, the orderly count, tailored to the nature of palynological analysis. We apply this method to diverse sediment catchments, including peat bogs, marine and lake sediments, from different geographical locations. Additionally, we revisit the reliability coefficients and propose adjustments for more accurate results. Our findings suggest that relying on statistical methods without considering the specific characteristics of palynological data may lead to low reliability. We advocate for the integration of dissimilarity criteria and the orderly count in sample size assessments for enhanced accuracy in palynological analyses. Our study emphasizes the importance of choosing appropriate methodologies aligned with the unique aspects of palynology to ensure robust and reliable results

Geological evolution of a tectonic and climatic transition zone: the Beyşehir-Suğla basin, lake district of Turkey

Central-west Turkey is a transition zone both tectonically and climatically between the quite different central and western regions of Anatolia. Central Anatolia represents the seismically quiet part of the otherwise highly active Turkey. On the other hand, this region has some of the lowest precipitation and highest evaporation ratios of Turkey. Conversely, west Anatolia is one of the most rapidly extending regions of the world and seismically very active. The climate is very different from the central part of Turkey and more humid. The zone between these two regions is also known geologically as the Isparta Angle. This reverse-V-shaped fold and thrust belt has several lake basins today, which have archived the geological and geomorphological history of this tectonic and climatic transition zone. The Beyşehir-Suğla basin is located on the eastern part of this zone. This NW–SE trending basin includes the largest natural freshwater lake of the Mediterranean region: Lake Beyşehir. Lakes Beyşehir and Suğla are located in this tectonic depression that discharge into an incised river gorge opening to the Konya closed basin. In order to shed light on the development of the Beyşehir-Suğla basin, our study was mainly conducted within the Neogene and Quaternary units of the region. Our structural results indicate that the depression was probably formed by a transtensional regime in the middle Miocene, which is controlled by extensional tectonics since the early Quaternary. Also, the current depression has mainly embodied the structures that are the products of these tectonic phases. According to our sedimentary data and palaeoecological interpretation of available palaeontological data, the Beyşehir-Suğla basin was developed initially under a humid and warm climate in the middle Miocene; then since the late Miocene-Pliocene it was controlled by a relatively more arid and, at times, humid climate more like the central Anatolian basins. Although the Beyşehir-Suğla basin is hydrologically connected to the Konya closed basin in central Anatolia, it was protected from arid climatic conditions for over millions of years as evidenced by the lack of evaporites in the studied basin and surrounding basins located in the interior part of the Isparta Angle. While the regional climate seems to have changed consistently with the geomorphic response to large-scale tectonics (i.e. orographic barrier development), the Beyşehir-Suğla basin seems to be protected from hydrological closure by the existence of karstic features in the surrounding carbonate basement rocks

Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}$and correspond to an integrated luminosity of$4.6\;{\rm f}{{{\rm b}}^{-1}}$. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum${{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}$and pseudorapidity$|\eta |\lt 1.9$, is measured to be${{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques