243 research outputs found
(S)-(+)-1-(2-Bromophenyl)ethanol
The title compound, C8H9BrO, crystallizes with two molecules in the asymmetric unit. The structure displays O—H⋯O hydrogen bonding, generating zigzag chains evolving around a screw axis along [100]
Sedimentary context and palaeoecology of Gigantoproductus shell beds in the Mississippian Eyam Limestone Formation, Derbyshire carbonate platform, central England
A sedimentological study was conducted at two localities exposing the Mississippian Eyam Limestone Formation of the Derbyshire carbonate platform, UK. Ricklow Quarry comprises seven facies with diverse skeletal assemblages, representing deposition on the inner to middle ramp within open marine waters. Once-a-Week Quarry comprises four facies, dominated by crinoidal debris representing deposition on the inner ramp. Both localities expose Gigantoproductus shell beds. Palaeoecological analysis of a single shell bed from each locality enabled investigation of the rapid colonization and success of this taxon on the platform. At Ricklow Quarry, on the eastern side of a localized mud mound, both life (>72% of thin and thick-shelled brachiopods in life position) and neighbourhood assemblages are present. A low-moderate diversity community (<1.37 and <0.8 Shannon diversity index) rapidly established over relict Brigantian mud mounds. Shell beds are preluded by intervals of decreased energy that allowed larvae to settle. Once established, the dominance of thick-shelled individuals enabled baffling, potentially providing localized shelter for larvae and nearby individuals. At Once-a-Week Quarry, where no mud mound is present, only thick-shelled Gigantoproductus species and a low diversity community (<1.07 Shannon diversity index) exclusively comprising neighbourhood assemblages (37% in life position) is present. The presence of inactive mud mounds at Ricklow Quarry appears to have been the key to the success of Gigantoproductus species enabling the onset of stable communities in the shelter provided by the relict mound. Once the first palaeocommunities were established, larvae dispersed and colonized higher energy settings, such as at Once-a-Week Quarry
Robotic monitoring of forests: a dataset from the EU habitat 9210* in the Tuscan Apennines (central Italy)
Effective monitoring of habitats is crucial for their preservation. As the impact of anthropic activities on natural habitats increases, accurate and up-to-date information on the state of ecosystems has become imperative. This paper presents a new dataset collected from the forests located in the Tuscan Apennines (Italy) using the ANYmal robot. The dataset provides information regarding the structure and composition of the EU priority habitat 9210*. The dataset, which is publicly available through a Zenodo repository, includes photos, videos, and point clouds of the environment. This dataset is a valuable resource for the scientific community working in the field of forest ecology and conservation and has the potential to inform future research and conservation efforts on habitat 9210*. the collaboration between robotic engineers and plant scientists provides a unique perspective on the forest ecosystem and underscores the potential for interdisciplinary work in this field. This dataset constitutes an important contribution to the ongoing effort to monitor and conserve habitats globally, particularly in light of the challenges posed by global changes
Revisiting the upper Visean mud mounds from Derbyshire (UK): the role of brachiopods in their growth
Several brachiopod-rich mud mounds occur in the upper Visean (Brigantian) of the Derbyshire Carbonate Platform succession in UK. The re-evaluation of the lithofacies architecture of a Derbyshire mud mound complex, developed in an intraplatform middle-ramp environment, led to the recognition of three lithofacies associations: (a) a 10 m thick basal unit of automicrite boundstone with siliceous sponge spicules and brachiopod–bryozoan packstone to wackestone beds; (b) a 10 m thick, 250 m wide, lens-shaped, convex-up massive core of clotted peloidal micrite and fenestellid bryozoan boundstone with sponge spicules; (c) inclined brachiopod–bryozoan–crinoid packstone flank beds. In the mud mound complex core, most of the carbonate mud with clotted peloidal and structureless micrite fabric is the result of biologically induced and influenced in-situ precipitation processes (automicrite). Brachiopods are not, as previously thought, limited to storm-scoured “pockets” in the mud mound complex core but are abundant and diverse in all lithofacies and lived on the irregular mud mound complex surface concentrating in depressions sustained by automicrite boundstone and the growth of bryozoans and sponges. The upper Visean Derbyshire mud mounds are, thus, representatives of a newly defined fenestellid bryozoan–brachiopod–siliceous sponge mud mound category, occurring in various middle–upper Visean Western European sites, a sub-type of the fenestellid bryozoan–crinoid–brachiopod Type 3 buildups of Bridges et al. (1995). These mud mounds, and other types of brachiopod-rich buildups, developed in carbonate platform settings between fair-weather and storm wave base, in dysphotic environments with dispersed food resources during the Visean. Brachiopod mud mound colonisation was favoured by moderate water depth, availability of food resources, and diverse substrates
Serous cystic neoplasm of the pancreas: A multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)
OBJECTIVES:
Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.
DESIGN:
Retrospective multinational study including SCN diagnosed between 1990 and 2014.
RESULTS:
2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58\u2005years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40\u2005mm (2-200)), 9% had resection beyond 1\u2005year of follow-up (3\u2005years (1-20), size at diagnosis: 25\u2005mm (4-140)) and 39% had no surgery (3.6\u2005years (1-23), 25.5\u2005mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1\u2005year (n=1271), size increased in 37% (growth rate: 4\u2005mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).
CONCLUSIONS:
After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN
Alnus glutinosa Riparian Woodlands of Italy and Corsica: Phytosociological Classification and Floristic Diversity
A comparative analysis of the riparian vegetation dominated by Alnus glutinosa in Italy and Tyrrhenian islands, based on literature data and unpublished releves, is presented. A total of 456 phytosociological releves were processed. For the definition of plant communities and alliances, hierarchical clustering was performed by using Bray-Curtis coefficient and Detrended Correspondence Analysis ordination methods. Identification of diagnostic species of the vegetation units was performed by means of the phi fidelity index. Quantum GIS software version 3.6 was used for the interpolation of the bioclimatic variables and A. glutinosa communities. Overall, a total of 18 A. glutinosa-riparian wood communities were distinguished for Italy and Tyrrhenian islands, of which two new associations and one new subassassociation are described. The classification of the releves showed two main vegetation groups: the first one including the plant communities of the Osmundo-Alnion alliance, and the other including the vegetation of the Ligustro vulgaris-Alnion glutinosae alliance. This latest includes the riparian meso-thermophilous communities of central and northern Italy. Within the Osmundo-Alnion alliance, two subgroups can be recognized: the first one includes the thermophilous communities of the Hyperico hircini-Alnenion glutinosae sub-alliance, mainly spread in the Tyrrhenian islands, while the second group includes the mesophilous communities attributed to the new suballiance Struthioptero-Alnenion glutinosae, widespread in central Italy and the Corsican mountains. The present paper provides the first comprehensive and exhaustive scheme of the A. glutinosa riparian woodlands diversity in Italy and Corsica
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Deletion of the Imprinted Phlda2 Gene Increases Placental Passive Permeability in the Mouse
Genomic imprinting, an epigenetic phenomenon that causes the expression of a small set of genes in a parent-of-origin-specific manner, is thought to have co-evolved with placentation. Many imprinted genes are expressed in the placenta, where they play diverse roles related to development and nutrient supply function. However, only a small number of imprinted genes have been functionally tested for a role in nutrient transfer capacity in relation to the structural characteristics of the exchange labyrinthine zone. Here, we examine the transfer capacity in a mouse model deficient for the maternally expressed Phlda2 gene, which results in placental overgrowth and a transient reduction in fetal growth. Using stereology, we show that the morphology of the labyrinthine zone in Phlda2−/+ mutants is normal at E16 and E19. In vivo placental transfer of radiolabeled solutes 14C-methyl-D-glucose and 14C-MeAIB remains unaffected at both gestational time points. However, placental passive permeability, as measured using two inert hydrophilic solutes (14C-mannitol; 14C-inulin), is significantly higher in mutants. Importantly, this increase in passive permeability is associated with fetal catch-up growth. Our findings uncover a key role played by the imprinted Phlda2 gene in modifying placental passive permeability that may be important for determining fetal growth
Norwich COVID-19 testing initiative pilot: evaluating the feasibility of asymptomatic testing on a university campus
Background: There is a high prevalence of COVID-19 in university-age students, who are returning to campuses. There is little evidence regarding the feasibility of universal, asymptomatic testing to help control outbreaks in this population. This study aimed to pilot mass COVID-19 testing on a university research park, to assess the feasibility and acceptability of scaling up testing to all staff and students. Methods: This was a cross-sectional feasibility study on a university research park in the East of England. All staff and students (5625) were eligible to participate. All participants were offered four PCR swabs, which they self-administered over two weeks. Outcome measures included uptake, drop-out rate, positivity rates, participant acceptability measures, laboratory processing measures, data collection and management measures. Results: 798 (76%) of 1053 who registered provided at least one swab; 687 (86%) provided all four; 792 (99%) of 798 who submitted at least one swab had all negative results and 6 participants had one inconclusive result. There were no positive results. 458 (57%) of 798 participants responded to a post-testing survey, demonstrating a mean acceptability score of 4.51/5, with five being the most positive. Conclusions: Repeated self-testing for COVID-19 using PCR is feasible and acceptable to a university population
Brachiopods from the Cisuralian–Guadalupian of Darvaz, Tajikistan and implications for Permian stratigraphic correlations
In this paper, we describe the upper Cisuralian Safetdara and Gundara formations of the Darvaz mountains, North Pamir, which were part ofthe Kunlun Arc, developed along the active Eurasian margin. The Safetdara Formation comprises massive limestones (mainly cyanobacterial,Tubiphytes and Archaeolithoporella boundstones) alternating with well-bedded bioclastic and oncoidal limestones and an interval of recessiveshales. The formation crops out above the Chelamchi Formation consisting of turbiditic siltstones and sandstones with bioclastic silty limestonesyielding massive limestone olistoliths. The Gundara Formation consists of fine sandstones at the base, followed by well-bedded marly bioclastic,oncoidal and microbial limestones, bearing a rich silicified brachiopod fauna in life-position. Two new taxa have been identified in this association:the cemented coralliform Gundaria insolita n. gen. n. sp. and the pedicle attached Hemileurus politus n. sp. The inferred environmental setting isthat of shoal deposits of warm, shallow, high energy, clear marine waters for the Safetdara Formation. The agglutinated microbial reefs to clusterreefs of the Gundara Formation were probably growing in a muddier, quieter and probably slightly deeper setting.The foraminifers of the Brevaxina Zone suggest a Bolorian age for the top of the Chelamchi Formation, the Safetdara Formation and the baseof the Gundara Formation. Kungurian conodonts have been found in the lower part of the Safetdara Formation. The biostratigraphic data from thesedimentary succession of North Pamir, integrated with those already obtained from Southeast Pamir, allow to refine the correlations between theTethyan regional scale and the International Time Scale. In particular, it seems now clear that the Bolorian and the lower part of the Kubergandiancorrelate to the Kungurian
Assessing kinetic fractionation in brachiopod calcite usingclumped isotopes
Brachiopod shells are the most widely used geological archive for the reconstruction of the temperature and the oxygen isotope composition of Phanerozoic seawater. However, it is not conclusive whether brachiopods precipitate their shells in thermodynamic equilibrium. In this study, we investigated the potential impact of kinetic controls on the isotope composition of modern brachiopods by measuring the oxygen and clumped isotope compositions of their shells. Our results show that clumped and oxygen isotope compositions depart from thermodynamic equilibrium due to growth rate-induced kinetic effects. These departures are in line with incomplete hydration and hydroxylation of dissolved CO2. These findings imply that the determination of taxon-specific growth rates alongside clumped and bulk oxygen isotope analyses is essential to ensure accurate estimates of past ocean temperatures and seawater oxygen isotope compositions from brachiopods
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