400 research outputs found
Chitons (Mollusca, Polyplacophora) from São Tomé and Príncipe Islands
No full textThe chiton fauna of São Tomé and Príncipe Islands is poorly known and here we present the first
comprehensive and illustrated account of living Polyplacophora from these islands. Four species have been
reported to date: Lepidochitona rolani Kaas & Strack, 1986, Chiton lyratus Sowerby, 1840, Chiton canariensis
d’Orbigny, 1839 and Notoplax productus (Carpenter in Pilsbry, 1892). Two of these species are actually
valid, while C. lyratus is considered a synonym of Rhyssoplax canariensis. N. productus was incorrectly
considered to be the valid name for Craspedochiton foresti (Leloup, 1965). The present paper increases the
list of living chiton species to 12, of which two are described as new, namely Stenoplax hernandezi sp. n.
and Callochiton saotomensis sp. n. Three species are assigned only at generic level but reflect new records
for these islands. Type specimens of Chiton lyratus and Chiton canariensis are figured
The multifaceted roles of sulfane sulfur species in cancer-associated processes
No full textSulfane sulfur species comprise a variety of biologically relevant hydrogen sulfide (H2S)-derived species, including per- and poly-sulfidated low molecular weight compounds and proteins. A growing body of evidence suggests that H2S, currently recognized as a key signaling molecule in human physiology and pathophysiology, plays an important role in cancer biology by modulating cell bioenergetics and contributing to metabolic reprogramming. This is accomplished through functional modulation of target proteins via H2S binding to heme iron centers or H2S-mediated reversible per- or poly-sulfidation of specific cysteine residues. Since sulfane sulfur species are increasingly viewed not only as a major source of H2S but also as key mediators of some of the biological effects commonly attributed to H2S, the multifaceted role of these species in cancer biology is reviewed here with reference to H2S, focusing on their metabolism, signaling function, impact on cell bioenergetics and anti-tumoral properties
Pennsylvanian carbonate platforms in distal shelf areas of a marine foreland basin (Escalada Fm., NW Spain)
No full textThe Carboniferous foreland basin located in the western European Variscan belt (Cantabrian Mountains, N Spain) was filled by progradational clastic wedges showing a regional lateral transition from proximal alluvial conglomerates and coal-bearing deltaic sequences to distal fine-grained marine deposits including carbonates. Carbonate beds alternating with sandstones, siltstones and mudstones distally converged forming flat-topped carbonate platforms. The two most extensive and thick (hundred of metres) carbonate units, developed in the Ponga Nappe Province, have been addressed jointly as Escalada Fm.
During a first stage (Kashirian-Podolskian), the Escalada Fm. platform covered nearly 5000 km2 and reached a mean thickness of 300 m, interfingering landward with deltaic cyclothems (Sama Group). Distally, the carbonate platform developed a steep, 500 m-high slope, fronting a starved basinal area (Beleño Fm.). The depositional slope consisted of thick steeply dipping strata (in situ microbial boundstones), which pinched out into calciturbidites, argillaceous spiculites and breccias at the toe of slope. Platform margin mostly aggraded, but minor progradational and retrogradational phases occurred. Platform-top carbonate successions comprise: 1) a lower part consisting of coated-grain and ooidal-grainstone packages (accumulated in high-energy areas close to the platform margin); and 2) a 200-300 m-thick upper part, mainly composed of tabular and mound-shaped beds of skeletal pack- to wackestones including algal colonies (beresellids and red phylloids), in situ precipitated microbial micrite and locally early marine cementation.
In a second stage (lower Myachkovian) a new Escalada Fm. platform developed beyond the previous platform margin, once the starved basinal areas (Beleño Fm.) were filled-up by a renewed clastic input. The 200 m-thick succession is arranged in tens of metre-thick, 4th-5th order shallowing upward cycles, characteristic of icehouse periods: absence of peritidal carbonates and presence of palaeokarsts at the cycle boundaries. Shoreward, limestone strata intercalated with sandstones, siltstones and mudstones (Fito Fm.) mainly consisting of two lithofacies: a) nodular, skeletal wackestones including siliceous sponge spicules, Chaetetes, calcispheres, foraminifers and echinoderms; and, b) up to 70 m-thick, massive algal boundstones with microbial micrite and early marine cements. Landwards, carbonate facies are marls, nodular wackestones and red and Anthracoporella algal bafflestones.
The Escalada and Fito Formations record the interaction between carbonate production and siliciclastic input into an active foreland basin, when not only tectonics but also glacioeustasy affected relative sea-level changes. The carbonate platforms are interpreted as highstand and transgressive deposits of 3rd order sequences, covering vast distal realms of a siliciclastic shelf, while basin infill phases mostly coincided with lowstands
Facilitating pain assessment and communication in people with deafness: a systematic review
No full textBackground: Pain is a common reason for seeking out healthcare professionals and support services. However, certain populations, such as people with deafness, may encounter difficulties in effectively communicating their pain; on the other side, health care professionals may also encounter challenges to assess pain in this specific population. Aims: To describe (a) the state of the research in the field of pain assessment in individuals with deafness; (b) instruments validated; and (b) strategies facilitating the pain communication or assessment in this population. Methods: A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were performed, searching Medline, CINAHL, Scopus, Embase and PsycInfo databases, from their initiation to July 2023. Primary and secondary studies, involving adults with deafness and investigating pain assessment and communication difficulties, facilitators, or barriers, were eligible. The included studies were assessed in their methodological quality with the Quality Assessment for Diverse Studies tool; data extraction and the narrative synthesis was provided by two researchers. Results: Five studies were included. Two were validation studies, while the remaining were a case report, a case study and a qualitative study. The interRAI Community Health Assessment and the Deafblind Supplement scale have been validated among people with deafness by reporting few psychometric properties; in contrast, instruments well established in the general population (e.g. Visual Analogue Scale) have been assessed in their usability and understandability among individuals with deafness, suggesting their limitations. Some strategies have been documented as facilitating pain communication and assessment: (a) ensuring inclusiveness (the presence of family members as mediators); (b) ensuring the preparedness of healthcare professionals (e.g. in sign language); and (c) making the environment friendly to this population (e.g. removing masks). Conclusions: The research regarding pain in this population is in its infancy, resulting in limited evidence. In recommending more research capable of establishing the best pain assessment instrument, some strategies emerged for assessing pain in which the minimum standards of care required to offer to this vulnerable population should be considered
1,3-Dipolar cycloadditions with: Meso -tetraarylchlorins-site selectivity and mixed bisadducts
No full textThe 1,3-dipolar cycloaddition reaction of meso-tetraarylporphyrins with nitrones gives isoxazolidine-fused chlorins. Depending on the substitution pattern on the meso-aryl groups and the nitrone, the chlorins can be obtained in high yields (up to 91%). Bacteriochlorin-type bisadducts are also obtained, although in low yield, from the reaction of meso-tetrakis(pentafluorophenyl)porphyrin with N-methyl, N-cyclohexyl or N-benzyl nitrone. The structure of a bis(N-benzyl isoxazolidine-fused) bacteriochlorin was determined by single-crystal X-ray diffraction and rationalized by DFT calculations. To further explore the nature of site selectivity in the formation of bisadducts, isomeric mixed bacteriochlorins and isobacteriochlorins were synthesized by two complementary routes that involved the sequential addition of two types of 1,3-dipoles to the porphyrin macrocycle: a nitrone and an azomethine ylide. The photophysical properties of the mixed bacteriochlorins were evaluated and the results were compared with the reported data for other meso-tetraarylbacteriochlorins
Pennsylvanian carbonate platforms adjacent to deltaic systems in an active marine foreland basin (Escalada Fm., Cantabrian Zone, NW Spain)
No full textThe authors acknowledge financial support by the Spanish Ministerio de Ciencia e Innovacion (MICINN)project CGL-2008-00734/B
Individuals with hearing impairment/deafness during the COVID-19 pandemic: A rapid review on communication challenges and strategies
No full textThis study aimed (a) to identify the communication issues and problems faced by individuals with hearing impairment (HI)/deafness during the COVID-19 pandemic and (b) to describe strategies to overcome the issues/problems and/or prevent their negative impact
Author's personal copy Relationships of Afroablepharus Greer, 1974 skinks from the Gulf of Guinea islands based on mitochondrial and nuclear DNA: Patterns of colonization and comments on taxonomy
No full textPartial sequences of three mitochondrial DNA genes, 12S rDNA, 16S rDNA and cytochrome b, and one nuclear gene, c-mos, were used to assess the phylogenetic relationships of species belonging to the genus Afroablepharus from the volcanic islands of the Gulf of Guinea (West Africa) and neighboring continental Africa. Additionally, partial sequences of cytochrome b were used to compare levels of sequence divergence within populations. The three forms from São Tomé, Prı́ncipe and Annobon (one per island) are genetically dis-tinct, with high levels of divergence, supporting the recognition of a distinct species in each island. Populations within each island contain very low levels of genetic diversity. These three forms form a monophyletic group suggesting a single initial colonization followed by radiation to the other islands, possibly from São Tome ́ to Prı́ncipe and Annobon. This is contrary to what was found in other reptiles from these islands such as Mabuya (sensu lato) and Hemidactylus, which colonized the islands multiple times. Assuming a molecular clock for cytochrome b of about 2 % divergence per million years (usually applied to Sauria), the lineage on Annobon island exceeds the age of the island, thus casting further doubt on this widely used divergence estimate. Partial sequences of c-mos showed no variation within islands. Five to seven sites were variable among islands, which is a high value further supporting the treatment of each island form as a distinct species
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