782 research outputs found
Hydra tropomyosin TROP1 is expressed in head-specific epithelial cells and is a major component of the cytoskeletal structure that anchors nematocytes
A cDNA clone encoding a 253 amino acid tropomyosin was
isolated from
Hydra in a differential screen for headspecific
genes. The Hydra tropomyosin gene, designated
trop1, is a single copy gene, lacks introns and is strongly
expressed in tentacle-specific epithelial cells. Analysis of
protein synthesis in head and gastric tissue indicated a high
rate of tropomyosin synthesis in head tissue. Immunolocalization
of tropomyosin in tentacle tissue revealed a
cushion-like tropomyosin-containing structure within
battery cells at the base of nematocytes. The structure
appears to form part of the cytoskeletal anchor for nematocytes.
Tropomyosin cushions were also observed in
epithelial cells along the body column, which contain
mounted stenotele nematocytes
Modeled Saharan desert dust radiative effects over the Iberian Peninsula and Atlantic ocean
Ponencia presentada en: XXXI Jornadas CientĂficas de la AME y el XI Encuentro Hispano Luso de MeteorologĂa celebrado en Sevilla, del 1 al 3 de marzo de 2010.The work was funded by the Portuguese FCT through grant SFRH/BD/27870/2006 and through project PTDC/CTE-ATM/65307/2006
ConcepçÔes de evolução entre alunos do sétimo ano do ensino fundamental em uma escola brasileira
A teoria da Origem das EspĂ©cies Ă© um conceito chave para a compreensĂŁo da diversidade biolĂłgica e suas adaptaçÔes. Os alunos tĂȘm contato aprofundado com estes temas em torno do sĂ©timo ano, dos doze, no ensino escolar brasileiro. No Brasil tem se observado um antagonismo entre posiçÔes religiosas e pessoais com as informaçÔes cientĂficas divulgadas em sala de aula. O professor lida com estas concepçÔes prĂ©vias que estĂŁo presentes em sua sala de aula ao abordar o tema da evolução. O objetivo deste estudo Ă© levantar as concepçÔes dos alunos sobre a evolução para permitir que o professor conheça melhor o ambiente em que suas aulas sĂŁo ministradas. Foram utilizados questionĂĄrios com os alunos e uma anĂĄlise dos materiais didĂĄticos utilizados pelo professor. ConclusĂ”es apontam para um desconhecimento do tema pelos alunos, com mais ausĂȘncia de informação do que distorçÔes no conceito
Leveraging deep neural networks for automatic and standardised wound image acquisition
Wound monitoring is a time-consuming and error-prone activity performed daily by healthcare professionals. Capturing wound images is crucial in the current clinical practice, though image inadequacy can undermine further assessments. To provide sufficient information for wound analysis, the images should also contain a minimal periwound area. This work proposes an automatic wound image acquisition methodology that exploits deep learning models to guarantee compliance with the mentioned adequacy requirements, using a marker as a metric reference. A RetinaNet model detects the wound and marker regions, further analysed by a post-processing module that validates if both structures are present and verifies that a periwound radius of 4 centimetres is included. This pipeline was integrated into a mobile application that processes the camera frames and automatically acquires the image once the adequacy requirements are met. The detection model achieved [email protected] values of 0.39 and 0.95 for wound and marker detection, exhibiting a robust detection performance for varying acquisition conditions. Mobile tests demonstrated that the application is responsive, requiring 1.4 seconds on average to acquire an image. The robustness of this solution for real-time smartphone-based usage evidences its capability to standardise the acquisition of adequate wound images, providing a powerful tool for healthcare professionals.info:eu-repo/semantics/publishedVersio
Penetration of ultravioletâB radiation in oligotrophic regions of the oceans during the Malaspina 2010 expedition
Few studies have investigated ultraviolet (UV) radiation in the open ocean besides its harmful effects on organisms and influence on biogeochemical processes. Here, we assessed UV attenuation, with particular focus on UVâB, across the (sub)tropical ocean during the Malaspina 2010 Circumnavigation. Vertical UV radiometer profiles together with Chlâ
a
concentration, and UV absorption by CDOM (
a
CDOM
(
λ
)) and by suspended particulate matter (
a
p
(
λ
)) were measured at 117 stations. At photosynthetically active radiation (PAR) and across UVâA and UVâB wavelengths, the lowest downwelling attenuation coefficients (
K
d
) during the expedition were recorded in ultraâoligotrophic regions at 5°â15°S (mean
K
d
(305Â nm): 0.129Â m
â1
, mean
K
d
(313Â nm): 0.107Â m
â1
) in the Indian and South Pacific Oceans. The waters here were comparatively more transparent than at 5°â15°N (mean
K
d
(305Â nm): 0.239Â m
â1
, mean
K
d
(313Â nm): 0.181Â m
â1
) where equatorial upwelling occurs.
K
d
was highest near the Costa Rica Dome (
K
d
(313Â nm): 0.226Â m
â1
) and at the confluence of the Benguela and Agulhas currents (
K
d
(313Â nm): 0.251Â m
â1
). The contribution of
a
p
(
λ
) toward nonwater absorption (
a
nw
(
λ
)) was significantly lower at 305Â nm than at 313 and 320Â nm, suggesting the contribution of absorption by detritus and phytoplankton particles decreases compared with that of CDOM absorption as UVâB wavelength decreases. Both
a
CDOM
(
λ
) and
a
p
(
λ
) at UVâB wavelengths were lowest in the Indian Ocean whereas
K
d
was lowest in the South Pacific. This finding emphasizes that other factors besides absorption, such as scattering by reflective phytoplankton or inorganic particles, strongly influence UVâB attenuation in open ocean waters.Plain Language Summary: We assessed water transparency to UVâB radiation across the tropical and subtropical ocean as part of the Malaspina 2010 Expedition. UVâB radiometer profiles, Chlorophyllâa, and UVâB absorption by organic matter and suspended particles were measured at 117 stations. The most UVâB transparent waters were found in regions where nutrients are extremely low, particularly at 5°â15°S in the Indian and South Pacific Oceans. Here, ocean waters were considerably more transparent than 5°â15°N, which suggests that at a given depth southern hemisphere marine organisms experience higher UVâB exposure than their northern counterparts. The least UVâB transparent waters were near the Costa Rica Dome and at the confluence of the Benguela and Agulhas currents. UVâB absorption by organic matter and suspended particles, and Chlâ
a
concentration were lowest in the Indian Ocean. The contribution of suspended particles toward nonwater absorption was significantly lower at 305Â nm than at 313 and 320Â nm, and higher in the clearest waters of the Indian Ocean than in the Subtropical South Pacific. Absorptions by organic matter and suspended particles were lowest in the Indian Ocean whereas UVâB attenuation was lowest in the South Pacific, which highlights the complex relationship between optical properties in the UVâB spectrum.Ministerio de Ciencia e InnovaciĂłn | Ref. CSD2008-00077King Abdullah University of Science and Technology | Ref. BAS/1/1072-01-0
Cupressaceae Pollen in the City of Ăvora, South of Portugal: Disruption of the Pollen during Air Transport Facilitates Allergen Exposure
Research Highlights: Daily airborne Cupressaceae pollen disruption ranged from 20 to 90%; relative humidity (RH), rainfall and atmospheric pressure (AtP) were the major meteorological determinants of this phenomenon. Background and Objectives: Cupressaceae family includes several species that are widely used as ornamental plants pollinating in late winter-early spring and might be responsible for allergic outbreaks. Cupressaceae pollen disruption may favour allergen dissemination, potentiating its allergenicity. The aim of this work was to characterize the Cupressaceae pollen aerobiology in Ăvora, South of Portugal, in 2017 and 2018, particularly the pollen disruption, and to identify the meteorological parameters contributing to this phenomenon. Materials and Methods: Pollen was collected using a Hirst type 7-day pollen trap and was identified following the standard methodology. Temperature, RH, rainfall, global solar radiation (Global Srad), AtP, wind speed and direction were obtained from a weather station installed side-by-side to the Hirst platform. Back trajectories (12-h) of air masses arriving at Ăvora were calculated using the HYSPLIT model. Results: Cupressaceae pollen index was higher in 2017 compared to 2018 (>5994 and 3175 pollen/m3, respectively) and 36 ± 19% (2017) and 64 ± 17% (2018) of the pollen was disrupted. Higher levels of disrupted pollen coincided with RH > 60% and rainfall. Temperature, Global Srad and AtP correlated negatively with pollen disruption. Wind speed and wind direction did not significantly correlate with pollen disruption. Intra-diurnal pollen pattern peaked between 9:00 amâ2:00 pm, suggesting local origin, confirmed by the back trajectory analysis. Intra-diurnal pollen disruption profile followed hourly pollen pattern and it negatively correlated with AtP, temperature and Global Srad but was uncorrelated with RH. Conclusions: The results suggest that RH, rainfall and AtP are the main factors affecting airborne Cupressaceae pollen integrity and in conjunction with daily pollen concentration may be used to predict the risk of allergy outbreaks to this pollen type
Patterns and drivers of UV absorbing chromophoric dissolved organic matter in the euphotic layer of the open ocean
The global distribution of chromophoric dissolved organic matter (CDOM) in the euphotic layer of the Atlantic, Indian, and Pacific oceans (between 35° N and 40° S) was analyzed by absorption spectroscopy during the Malaspina 2010 circumnavigation. Absorption coefficients at 254 nm (a254) and 325 nm (a325), indices (a254/a365) and spectral slopes (between 275 and 295 nm, S275-295) were calculated from the dissolved fraction of the UV absorption spectra to describe the amount and quality of CDOM. Generalized Additive Models (GAMs) were applied to evaluate the relevance of physical and biogeochemical drivers for the variability of CDOM. Besides the low CDOM values, a first division of our data following the Longhurstâs biogeographic classification showed significant differences in CDOM levels among provinces. The lowest values of a254 and a325 were found in the oligotrophic gyres, particularly in the Indian Ocean, and the highest in the upwelling areas, particularly in the Equatorial Pacific. Opposite distributions were obtained for S275-295 and a254/a365, indicative of higher photobleaching in the gyres. Within each province, whereas a254 was constant through the photic layer, a325 increased significantly with depth as a result of the dominance of photobleaching over biological production in the surface layer and the opposite at depth. The Pacific provinces, including the subtropical gyres, showed, however, significantly higher a325 values, indicative of lower photobleaching/higher biological production. The GAM analysis indicates that a254 and a325 were primarily related to chlorophyll a (Chl a), exhibiting a significant positive linear response. Interestingly, Prochlorococcus and Synechococcus abundances were related to these absorption coefficients. Apparent oxygen utilization also contributed to explain the distributions of these absorption coefficients, being inversely related to a254 and directly related to a325. These results are consistent with the premise that a254 could be a proxy for the concentration of dissolved organic carbon and a325 for the aromatic by-products of biological degradation. The GAM analysis also shows that a254/a365 and S275-295 exhibited inverse relationships with solar radiation, indicating that the biological production of CDOM counteracts photodegradation as solar radiation increases. In summary, whereas photobleaching dictates the vertical distribution of CDOM, Chl a explains the CDOM differences among the photic layer of the tropical and subtropical ocean provinces visited during the circumnavigationMinisterio de EconomĂa y Competitividad | Ref. CDS2008-0007
Water-sediment physicochemical dynamics in a large reservoir in the Mediterranean region under multiple stressors
Nowadays, the Mediterranean freshwater systems face the threat of water scarcity, along with multiple other stressors (e.g., organic and inorganic contamination, geomorphological alterations, invasive species), leading to the impairment of their ecosystem services. All these stressors have been speeding up, due to climate variability and land cover/land use changes, turning them into a big challenge for the water management plans. The present study analyses the physicochemical and phytoplankton biomass (chlorophyll-a) dynamics of a large reservoir, in the Mediterranean region (Alqueva reservoir, Southern Portugal), under diverse meteorological conditions and land cover/land use real scenarios (2017 and 2018). The most important stressors were identified and the necessary tools and information for a more effective management plan were provided. Changes in these parameters were further related to the observed variations in the meteorological conditions and in the land cover/land use. The increase in nutrients and ions in the water column, and of potentially toxic metals in the sediment, were more obvious in periods of severe drought. Further, the enhancement of nutrients concentrations, potentially caused by the intensification of agricultural activities, may indicate an increased risk of water eutrophication. The results highlight that a holistic approach is essential for a better water resources management strategy
Exploring alternative marine lipid sources as substitutes for fish oil in Farmed Sea bass (Dicentrarchus labrax) and their influence on organoleptic, chemical, and nutritional properties during cold storage
This study evaluated the replacement of fish oil (sardine oil) by different combinations of alternative marine lipid ingredients as sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in European sea bass (Dicentrarchus labrax) throughout 14âdays of ice storage. A practical diet (SARDINE) was used as a control, which included 9% sardine oil and 4.4% soybean oil, providing 2.3% of EPAâ+âDHA. Two other experimental diets were formulated to achieve the same EPAâ+âDHA values but completely devoid of soybean oil. In the ALGABLEND diet, 6.7% of salmon oil (salmon by-product) and 2% of algae biomass (Algaessence Feedâą) partially replaced sardine oil. In the ALGAOIL diet, sardine oil was totally replaced with 10.1% salmon by-product oil and 3.3% algae oil (VeramarisÂź). All diets were equally well-accepted by European sea bass, resulting in similar growth performance, somatic indexes, and whole body composition. At the end of the trial, no significant differences were found in the EPAâ+âDHA levels of fish muscle between dietary treatments, resulting in high values of EPAâ+âDHA (> 0.62âg 100âgâ1). Furthermore, replacing fish oil did not significantly affect the organoleptic and chemical properties of the fish samples. Parameters such as pH, water holding capacity, lipid oxidation, antioxidant capacity, color and texture presented similar values to those obtained for fish fed the SARDINE diet during the 14âdays of storage in ice. In conclusion, these results show that combining algal oil (VeramarisÂź), algae blend (Algaessence Feedâą) and salmon by-product oil can be a successful strategy for the fortification of European sea bass muscle in EPA and DHA while ensuring fish freshness, nutritional quality, and consumersâ health
Prokaryotic capability to use organic substrates across the global tropical and subtropical ocean
Prokaryotes play a fundamental role in decomposing organic matter in the ocean, but little is known about how microbial metabolic capabilities vary at the global ocean scale and what are the drivers causing this variation. We aimed at obtaining the first global exploration of the functional capabilities of prokaryotes in the ocean, with emphasis on the under-sampled meso- and bathypelagic layers. We explored the potential utilization of 95 carbon sources with Biolog GN2 platesÂź in 441 prokaryotic communities sampled from surface to bathypelagic waters (down to 4,000 m) at 111 stations distributed across the tropical and subtropical Atlantic, Indian, and Pacific oceans. The resulting metabolic profiles were compared with biological and physico-chemical properties such as fluorescent dissolved organic matter (DOM) or temperature. The relative use of the individual substrates was remarkably consistent across oceanic regions and layers, and only the Equatorial Pacific Ocean showed a different metabolic structure. When grouping substrates by categories, we observed some vertical variations, such as an increased relative utilization of polymers in bathypelagic layers or a higher relative use of P-compounds or amino acids in the surface ocean. The increased relative use of polymers with depth, together with the increases in humic DOM, suggest that deep ocean communities have the capability to process complex DOM. Overall, the main identified driver of the metabolic structure of ocean prokaryotic communities was temperature. Our results represent the first global depiction of the potential use of a variety of carbon sources by prokaryotic communities across the tropical and the subtropical ocean and show that acetic acid clearly emerges as one of the most widely potentially used carbon sources in the ocean
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