Despite international waters covering over 60% of the world's oceans, understanding of how fisheries in these regions shape ecosystem processes is surprisingly poor. Seabirds forage at fishing ...vessels, which has potentially deleterious effects for their population, but the extent of overlap and behavior in relation to ships is poorly known. Using novel biologging devices, which detect radar emissions and record the position of boats and seabirds, we measured the true extent of the overlap between seabirds and fishing vessels and generated estimates of the intensity of fishing and distribution of vessels in international waters. During breeding, wandering albatrosses (Diomedea exulans) from the Crozet Islands patrolled an area of over 10 million km² at distances up to 2500 km from the colony. Up to 79.5% of loggers attached to birds detected vessels. The extent of overlap between albatrosses and fisheries has widespread implications for bycatch risk in seabirds and reveals the areas of intense fishing throughout the ocean. We suggest that seabirds equipped with radar detectors are excellent monitors of the presence of vessels in the Southern Ocean and offer a new way to monitor the presence of illegal fisheries and to better understand the impact of fisheries on seabirds. A pesar de que las aguas internacionales cubren más del 60% de los océanos, el conocimiento sobre cómo las pesquerías en estas regiones le dan forma a los procesos del ecosistema es sorprendentemente pobre. Las aves marinas buscan alimento en los navíos de pesca, lo que presenta efectos potencialmente dañinos para su población. Aun así, la extensión de la coincidencia en el tiempo y el comportamiento en relación con los barcos no se conoce ampliamente. Con el uso de aparatos novedosos de bioregistro, los cuales detectan emisiones de radar y registran la posición de los barcos y las aves marinas, medimos la verdadera extensión de la coincidencia en el tiempo entre las aves marinas y los navíos de pesca, y generamos estimaciones de la intensidad de pesca y distribución de los navíos en aguas internacionales. Durante la época de reproducción, los albatros errantes (Diomedea exulans) de las Islas Crozet patrullaron un área de más de 10 millones de km² a distancias de hasta 2500 km desde la colonia. Hasta el 79.5% de los registradores de datos adjuntos a las aves detectaron navios. La extensión de la coincidencia en el tiempo entre los albatros y las pesquerías tiene implicaciones amplias para el riesgo de captura accesoria de aves marinas y revela las áreas de pesca intensa en el océano. Sugerimos que las aves marinas equipadas con detectores de radar son monitores excelentes de la presencia de navíos en el océano del sur y ofrecen una nueva manera de monitorear la presencia de pesca ilegal y de mejorar el entendimiento del impacto de la pesca sobre las aves marinas.
Droplet microfluidics is a powerful technology that finds many applications in chemistry and biomedicine. Among different configurations, droplets confined in a capillary (or plugs) present a number ...of advantages: they allow positional identification and simplify the integration of complex multi-steps protocols. However, these protocols rely on the control of droplet speed, which is affected by a complex and still debated interplay of various physico-chemical parameters like droplet length, viscosity ratio between droplets and carrier fluid, flow rate and interfacial tension. We present here a systematic investigation of the droplet speed as a function of their length and interfacial tension, and propose a novel, simple and robust methodology to control the relative distance between consecutive droplets flowing in microfluidic channels through the addition of surfactants either into the dispersed and/or into the continuous phases. As a proof of concept application, we present the possibility to accurately trigger in space and time the merging of two confined droplets flowing in a uniform cross-section circular capillary. This approach is further validated by monitoring a conventional enzymatic reaction used to quantify the concentration of H2O2 in a biological sample, showing its potentialities in both continuous and stopped assay methods.
The motion of liquid drops on solid surfaces is attracting a lot of attention because of its fundamental implications and wide technological applications. In this article, we present a comprehensive ...experimental study of the interaction between gravity-driven ferrofluid drops on very slippery oil-impregnated surfaces and a patterned magnetic field. The drop speed can be accurately tuned by the magnetic interaction, and more interestingly, drops are found to undergo a stick–slip motion whose contrast and phase can be easily tuned by changing either the strength of the magnetic field or the ferrofluid concentration. This motion is the result of the periodic modulation of the external magnetic field and can be accurately analyzed because the intrinsic pinning due to chemical defects is negligible on oil-impregnated surfaces.
Hematopoiesis is regulated by components of the microenvironment, so-called niche. Here, we show that p190-B GTPase-activating protein (p190-B) deletion in mice causes hematopoietic failure during ...ontogeny, in p190-B(-/-) fetal liver and bones, and in p190-B(+/-) adult bones and spleen. These defects are non-cell autonomous, as we previously showed that transplantation of p190-B(-/-) hematopoietic cells into wild-type (WT) hosts leads to normal hematopoiesis. Coculture of mesenchymal stem (MSC)/progenitor cells and wild-type bone marrow (BM) cells reveals that p190-B(-/-) MSCs are dysfunctional in supporting hematopoiesis owing to impaired Wnt signaling. Furthermore, p190-B loss causes alteration in BM niche composition, including abnormal colony-forming unit (CFU)-fibroblast, CFU-adipocyte and CFU-osteoblast numbers. This is due to altered MSC lineage fate specification to osteoblast and adipocyte lineages. Thus, p190-B organizes a functional mesenchymal/microenvironment for normal hematopoiesis during development.
Atmospheric airborne measurements of CO2 are very well suited for estimating the time-varying distribution of carbon sources and sinks at the regional scale due to the large geographical area covered ...over a short time. We present here an analysis of two cross-European airborne campaigns carried out on 23-26 May 2001 (CAATER-1) and 2-3 October 2002 (CAATER-2) over Western Europe. The area covered during CAATER-1 and CAATER-2 was 4° W to 14° E long; 44° N to 52° N lat and 1° E to 17° E long; 46° N to 52° N lat respectively. High precision in situ CO2 , CO and Radon 222 measurements were recorded. Flask samples were collected during both campaigns to cross-validate the in situ data. During CAATER-1 and CAATER-2, the mean CO2 concentration was 370.1 ± 4.0 (1-σ standard deviation) ppm and 371.7 ± 5.0 (1-σ) ppm respectively. A HYSPLIT back-trajectories analysis shows that during CAATER 1, northwesterly winds prevailed. In the planetary boundary layer (PBL) air masses became contaminated over Benelux and Western Germany by emissions from these highly urbanized areas, reaching about 380 ppm. Air masses passing over rural areas were depleted in CO2 because of the photosynthesis activity of the vegetation, with observations as low as 355 ppm. During CAATER-2, the back-trajectory analysis showed that air masses were distributed among the 4 sectors. Air masses were enriched in CO2 and CO over anthropogenic emission spots in Germany but also in Poland, as these countries have part of the most CO2 -emitting coal-based plants in Europe. Simultaneous measurements of in situ CO2 and CO combined with back-trajectories helped us to distinguish between fossil fuel emissions and other CO2 sources. The δCO/δCO2 ratios (R2 = 0.33 to 0.88, slopes = 2.42 to 10.37), calculated for anthropogenic-influenced air masses over different countries/regions matched national inventories quite well, showing that airborne measurements can help to identify the origin of fossil fuel emissions in the PBL even when distanced by several days/hundreds of kms from their sources. We have compared airborne CO2 observations to nearby ground station measurements and thereby, confirmed that measurements taken in the lower few meters of the PBL (low-level ground stations) are representative of the local scale, while those located in the free troposphere (FT) (moutain stations) are representative of atmospheric CO2 regionally on a scale of a few hundred kilometers. Stations located several 100 km away from each other differ from a few ppm in their measurements indicating the existence of a gradient within the free troposphere. Observations at stations located on top of small mountains may match the airborne data if the sampled air comes from the FT rather than coming up from the valley. Finally, the analysis of the CO2 vertical variability conducted on the 14 profiles recorded in each campaign shows a variability at least 5 to 8 times higher in the PBL (the 1-σ standard deviation associated to the CO2 mean of all profiles within the PBL is 4.0 ppm and 5.7 ppm for CAATER-1 and CAATER-2, respectively) than in the FT (within the FT, 1-σ is 0.5 ppm and 1.1 ppm for CAATER-1 and CAATER-2, respectively). The CO2 jump between the PBL and the FT equals 3.7 ppm for the first campaign and -0.3 ppm for the second campaign. A very striking zonal CO2 gradient of about 11 ppm was observed in the mid-PBL during CAATER-2, with higher concentrations in the west than in the east. This gradient may originate from differences in atmospheric mixing, ground emission rates or Autumn's earlier start in the west. More airborne campaigns are currently under analysis in the framework of the CARBOEUROPE-IP project to better assess the likelihood of these different hypotheses. In a companion paper (Xueref-Remy et al., 2011, Part 2), a comparison of vertical profiles from observations and several modeling frameworks was conducted for both campaigns.
People living with human immunodeficiency virus (HIV) are the individuals most affected by the current Monkeypox virus outbreak that was first announced in May 2022. Here we report Pan‐pox‐specific ...T‐cell responses in a cohort of HIV‐1‐infected individuals after receiving the nonreplicative, attenuated smallpox vaccine JYNNEOS from Bavarian Nordic. Intradermal (i.d.) and subcutaneous (s.c.) vaccination was safe without major side effects. Dose‐sparing i.d. vaccination was superior to s.c. vaccination and promoted T‐cell polyfunctionality, and the expression of the gut‐homing marker α4β7 integrin on lymphocytes. HIV‐1‐infected individuals with CD4 T‐cell counts ≤500/mm3 blood required at least a booster vaccination to exhibit efficient virus‐specific T‐cell responses. The magnitude of the Th1 response after this booster directly correlated with the CD4 T‐cell count of the vaccinees. Further studies with a larger number of participants are warranted to confirm and expand our observations.
The Rho guanosine triphosphatases (GTPases) Rad and Rac1 are critical signaling regulators in mammalian cells. The deletion of both Rac1 and Rac2 murine alleles leads to a massive egress of ...hematopoietic stem/progenitor cells (HSC/Ps) into the blood from the marrow, whereas$Rac1^{-/-}$but not Rac2-/-HSC/Ps fail to engraft in the bone marrow of irradiated recipient mice. In contrast, Rac2, but not Rac1, regulates superoxide production and directed migration in neutrophils, and in each cell type, the two GTPases play distinct roles in actin organization, cell survival, and proliferation. Thus, Rad and Rac2 regulate unique aspects of hematopoietic development and function.
Blockchains are a new digital technology that combines peer-to-peer network computing and cryptography to create an immutable decentralised public ledger. Where the ledger records money, a blockchain ...is a cryptocurrency, such as Bitcoin; but ledger entries can record any data structure, including property titles, identity and certification, contracts, and so on. We argue that the economics of blockchains extend beyond analysis of a new general purpose technology and its disruptive Schumpeterian consequences to the broader idea that blockchains are an institutional technology. We consider several examples of blockchain-based economic coordination and governance. We claim that blockchains are an instance of institutional evolution.
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