Macroplastics at sea around Antarctica Barnes, David K.A.; Walters, Adam; Gonçalves, Leandra
Marine environmental research,
08/2010, Letnik:
70, Številka:
2
Journal Article
Recenzirano
More so than at any previous time, there is a heightened awareness of the amount of plastic in the environment, it’s spread to even remote localities and the multiple influences of this on organisms. ...In the austral summer of 2007/08 Greenpeace and British Antarctic Survey ships (MV Esperanza and RRS James Clark Ross respectively) conducted the first co-ordinated joint marine debris survey of the planet’s most remote seas around East and West Antarctica to reveal floating macroplastics. With observations also made from the ice patrol vessel HMS Endurance in the same season and seabed samples collected from the RRS James Clark Ross, this was the widest survey for plastics ever undertaken around Antarctica.
The 2008 visit of RRS James Clark Ross to the Amundsen Sea breached two last frontiers; the last and most remote sea from which biological samples and plastic debris have been reported. A plastic cup and two fishing buoys were seen in the Durmont D’Urville and Davis seas while two pieces of plastic packaging and a fishing buoy were observed in the Amundsen Sea. Agassiz trawls revealed rich biodiversity on the Amundsen (and south Bellingshausen) seabed but no sunken plastic pieces. We found no microplastics in five epibenthic sledge samples (300 μm mesh) from the Amundsen seabed. The seabeds immediately surrounding continental Antarctica are probably the last environments on the planet yet to be reached by plastics, but with pieces floating into the surface of the Amundsen Sea this seems likely to change soon. Our knowledge now touches every sea but so does our legacy of lost and discarded plastic.
The use of DNA to deliver vaccine antigens offers many advantages, including ease of manufacture and cost. However, most DNA vaccines are plasmids and must be grown in bacterial culture, ...necessitating elements that are either unnecessary for effective gene delivery (for example, bacterial origins of replication) or undesirable (for example, antibiotic resistance genes). Removing these elements may improve the safety profile of DNA for the delivery of vaccines. Here, we describe a novel, double-stranded, linear DNA construct produced by an enzymatic process that solely encodes an antigen expression cassette, comprising antigen, promoter, polyA tail and telomeric ends. We compared these constructs (called 'Doggybones' because of their shape) with conventional plasmid DNA. Using luciferase-expressing constructs, we demonstrated that expression levels were equivalent between Doggybones and plasmids both in vitro and in vivo. When mice were immunized with DNA constructs expressing the HIV envelope protein gp140, equivalent humoral and cellular responses were induced. Immunizations with either construct type expressing hemagluttinin were protective against H1N1 influenza challenge. This is the first example of an effective DNA vaccine, which can be produced on a large scale by enzymatic processes.
Context. The spectra of four low-lying vibrational states of both anti and gauche conformers of normal-propyl cyanide were previously measured and analyzed in two spectral windows between 36 and 127 ...GHz. All states were then identified in a spectral line survey called Exploring Molecular Complexity with ALMA (EMoCA) toward Sagittarius B2(N) between 84.1 and 114.4 GHz with the Atacama Large Millimeter/submillimeter Array (ALMA) in its Cycles 0 and 1. Aims. We wanted to extend the measurements and analysis up to 506 GHz to provide accurate predictions over a much wider range of frequencies, quantum numbers and energies. Methods. We carried out measurements in two additional frequency windows up to 506 GHz. Results. For the gauche conformer, a large number of both a- and b-type transitions were identified. For the anti conformer, transitions were predominantly, but not exclusively, a-type. We hence improved molecular parameters for the ground states of both anti- and gauche-n-propyl cyanide and for excited vibrational states of the gauche conformer (v30 = 1, v29 = 1, v30 = 2, v28 = 1) and anti conformer (v30 = 1, v18 = 1, v30 = 2, v29 = 1) with high order coupling parameters determined between v18 = 1 and v30 = 2. Parameters are published for the first time for v18 = v30 = 1 of the anti conformer and for v29 = v30 = 1 of the gauche conformer. Conclusions. In total 15385 lines have been incorporated in the fits and should allow good predictions for unperturbed lines over the whole operating range of radio-telescopes. Evidence is found for vibrational coupling for some levels above 380 GHz. The coupling between v18 = 1 and v30 = 2 of the anti conformer has been well characterized. An additional list of 740 lines showing potential but as yet unidentified coupling has been provided for astrophysical identification.
The music in this portfolio represents an exploration of different approaches to fusing traditional Trinidadian elements with musical gestures and instrumentation more closely associated with the ...western classical tradition. The research that led to the creation of these scores focused on identifying apparent and hidden characteristics encoded in Trinidad's culture and in its musical styles, and on finding ways to bring these together in music ultimately intended to express aspects of Trinidad's culture in fresh ways. Fundamental to this research was the author's developing an understanding of the cultural context to which his compositions are a response and, crucially, of his own situatedness in relation to that context. Numerous field trips were undertaken to experience music-making in different cultural and religious situations in Trinidad. Participant observation was a fundamental research method in the author's attempts to internalize aspects of style and subsequently to draw upon these markers to define structures within new compositions. Research into approaches to cross-cultural musical fusion is timely given recent global political trends towards isolationism. New music shaped by structures and aesthetics from different traditions is by definition inclusive and, insofar as it embraces styles that may not be widely known, can encourage an awareness of cultures whose music historically may have experienced oppression or neglect. The creation of the pieces presented here included collaboration with Trinidadian artistes or with non-Trinidadian specialists on Trinidad. Such collaborations assisted in the exploration of ways to develop a musical voice intended to resonate with local audiences. All pieces in this portfolio were written for the University of Trinidad and Tobago's resident Ibis Ensemble, and for music students at the university. This commentary aims to contextualise the compositions that make up the portfolio by considering the issues that form a background to writing cross-cultural music in Trinidad.
Nanomedicine has had a profound impact on the treatment of many diseases, especially cancer. However, synthesis of multifunctional nanoscale drug carriers often requires multistep coupling and ...purification reactions, which can pose major scale-up challenges. Here, we leveraged bioinspired oxidation-triggered polymerization of catechols to synthesize nanoparticles (NPs) from the plant polyphenol quercetin (QCT) loaded with a hydrophobic anticancer drug, curcumin, and functionalized with poly(ethylene glycol) (PEG) for steric stabilization in one reaction step. NPs were formed by base-catalyzed oxidative self-polymerization of QCT in the presence of curcumin and thiol-terminated PEG upon mixing in a universal solvent (dimethyl sulfoxide), followed by self-assembly with the gradual addition of water. Dynamic light scattering and X-ray photoelectron spectroscopy were used to confirm NP PEGylation. Drug loading was verified by UV–vis spectroscopy. Curcumin-loaded NPs were efficiently internalized by CT26 murine colon cancer cells as determined by flow cytometry and confocal microscopy. NPs also demonstrated sustained release and potent cytotoxicity in vitro. Moreover, in vivo imaging of CT26 tumor-bearing Balb/c mice following tail vein injection of DiR-labeled QCT NPs showed steady tumor accumulation of the NPs up to 24 h. This was further supported by significant tumor uptake of curcumin-loaded QCT NPs as measured by flow cytometry analysis of tumor homogenates. Our findings present a greener synthetic route for the fabrication of drug-loaded surface-functionalized NPs from poorly water-soluble plant polyphenols such as QCT as promising anticancer delivery systems.
Context. We performed a spectral line survey called Exploring Molecular Complexity with ALMA (EMoCA) toward Sagittarius B2(N) between 84.1 and 114.4 GHz with the Atacama Large ...Millimeter/submillimeter Array (ALMA) in its Cycles 0 and 1. We determined line intensities of n-propyl cyanide in the ground vibrational states of its gauche and anti conformers toward the hot molecular core Sagittarius B2(N2) which suggest that we should also be able to detect transitions pertaining to excited vibrational states. Aims. We wanted to determine spectroscopic parameters of low-lying vibrational states of both conformers of n-propyl cyanide to search for them in our ALMA data. Methods. We recorded laboratory rotational spectra of n-propyl cyanide in two spectral windows between 36 and 127 GHz. We searched for emission lines produced by these states in the ALMA spectrum of Sagittarius B2(N2). We modeled their emission and the emission of the ground vibrational states assuming local thermodynamic equilibrium (LTE). Results. We have made extensive assignments of a- and b-type transitions of the four lowest vibrational states of the gauche conformer which reach J and Ka quantum numbers of 65 and 20, respectively. We assigned mostly a-type transitions for the anti conformer with J and Ka quantum numbers up to 48 and 24, respectively. Rotational and Fermi perturbations between two anti states allowed us to determine their energy difference. The resulting spectroscopic parameters enabled us to identify transitions of all four vibrational states of each conformer in our ALMA data. The emission features of all states, including the ground vibrational state, are well-reproduced with the same LTE modeling parameters, which gives us confidence in the reliability of the identifications, even for the states with only one clearly detected line. Conclusions. Emission features pertaining to the highest excited vibrational states of n-propyl cyanide reported in this work have been identified just barely in our present ALMA data. Features of even higher excited vibrational states may become observable in future, more sensitive ALMA spectra to the extent that the confusion limit will not have been reached. The 13C isotopomers of this molecule are expected to be near the noise floor of our present ALMA data. We estimate that transitions of vibrationally excited iso-propyl cyanide or aminoacetonitrile, for example, are near the noise floor of our current data as well.
Objectives There is little information about continued use of point‐of‐use technologies after disaster relief efforts. After the 2004 tsunami, the Red Cross distributed ceramic water filters in Sri ...Lanka. This study determined factors associated with filter disuse and evaluate the quality of household drinking water.
Methods A cross‐sectional survey of water sources and treatment, filter use and household characteristics was administered by in‐person oral interview, and household water quality was tested. Multivariable logistic regression was used to model probability of filter non‐use.
Results At the time of survey, 24% of households (107/452) did not use filters; the most common reason given was breakage (42%). The most common household water sources were taps and wells. Wells were used by 45% of filter users and 28% of non‐users. Of households with taps, 75% had source water Escherichia coli in the lowest World Health Organisation risk category (<1/100 ml), vs. only 30% of households reporting wells did. Tap households were approximately four times more likely to discontinue filter use than well households.
Conclusion After 2 years, 24% of households were non‐users. The main factors were breakage and household water source; households with taps were more likely to stop use than households with wells. Tap water users also had higher‐quality source water, suggesting that disuse is not necessarily negative and monitoring of water quality can aid decision‐making about continued use. To promote continued use, disaster recovery filter distribution efforts must be joined with capacity building for long‐term water monitoring, supply chains and local production.
Objectifs: Il y a peu d’informations sur l’utilisation continue des technologies sur les points d’utilisation après les efforts de secours aux sinistrés. Après le tsunami de 2004, la Croix‐Rouge a distribué des filtres d’eau en céramique au Sri Lanka. Cette étude a déterminé les facteurs associés à la désuétude des filtres et a évalué la qualité de l’eau de boisson des ménages.
Méthodes: Une enquête transversale sur les sources et traitement de l’eau, l’utilisation du filtre et les caractéristiques des ménages a été administrée par une interview orale et la qualité de l’eau des ménages a été testée. La régression logistique multivariée a été utilisée pour modéliser la probabilité de non utilisation du filtre.
Résultats: Au moment de l’enquête, 24% des ménages (107/452) n’utilisaient pas les filtres; la raison la plus souvent invoquée étant la rupture (42%). Les sources les plus communes en eau pour les ménages étaient des robinets et des puits. Les puits étaient utilisés par 45% des utilisateurs de filtre et 28% des non‐utilisateurs. Parmi les ménages ayant des robinets, 75% avaient des teneurs d’E. coli dans la catégorie la plus faible de risque de l’Organisation Mondiale de la Santé (<1/100 ml), contre seulement 30% des ménages déclarant l’utilisation d’eau de puits. Les ménages utilisant des robinets étaient ∼4 fois plus susceptibles de cesser d’utiliser le filtre que les ménages utilisant l’eau de puits.
Conclusion: Après deux ans, 24% des ménages étaient des non‐utilisateurs. Les principaux facteurs étaient la rupture et la source d’eau des ménages, les ménages avec des robinets étaient plus susceptibles d’arrêter l’utilisation que les ménages avec des puits. Les utilisateurs d’eau du robinet avaient également une source d’eau de qualité plus élevée, ce qui suggère que la désuétude n’était pas toujours néfaste et la surveillance de la qualité de l’eau peut aider à la prise de décision concernant l’utilisation continue. Afin de promouvoir l’utilisation continue, les efforts de distribution de filtres en cas de secours aux sinistrés devraient être conjoints au renforcement des capacités pour la surveillance de l’eau à long terme, les chaînes d’approvisionnement et la production locale.
Objetivos: Hay poca información sobre el uso continuado de tecnologías “punto de uso” después de los esfuerzos humanitarios por un desastre natural. Tras el tsunami del 2004, la Cruz Roja distribuyó filtros cerámicos de agua en Sri Lanka. En este estudio se determinan los factores asociados con el mal uso de los filtros, evaluando la calidad del agua potable en los hogares.
Métodos: Estudio croseccional de fuentes de agua y de su tratamiento; el uso de filtros y las características de los hogares se determinaron mediante una entrevista oral personal, y se midió la calidad del agua. Se realizó una regresión logística multivariada para modelar la probabilidad de no‐utilización del filtro.
Resultado: En el momento del estudio, un 24% de los hogares (107/452) no utilizaba los filtros; la razón más comúnmente dada para ello era que el filtro se había quebrado (42%). Las fuentes más comunes de agua para los hogares eran el grifo y los pozos. Los pozos eran utilizados por un 45% de los usuarios de filtros y por un 28% de quienes no los utilizaban. De los hogares con agua de grifo, un 75% tenía una fuente de agua con E. coli dentro del nivel de riesgo más bajo según la Organización Mundial de la Salud (<1/100 mL), vs. solo un 30% de los hogares que reportaron utilizar agua de pozos. Los hogares utilizando agua corriente tenían ∼4 veces más posibilidad de dejar de utilizar el filtro que aquellos hogares con agua proveniente de pozos.
Conclusión: Después de dos años, un 24% de los hogares no utilizaban el filtro de agua. Las principales razones para ello eran que el filtro se hubiese quebrado y la fuente de agua del hogar; los hogares con agua corriente tenían una mayor probabilidad de dejar de usar los filtros que las casas con pozos. Los usuarios de agua corriente también tenían una mejor calidad de agua, lo cual sugiere que la falta de uso de los filtros no es necesariamente negativa, y que la monitorización de la calidad del agua puede ayudar en la toma de decisiones sobre su uso continuado. Para promover el uso continuado de los filtros, los esfuerzos realizados en su distribución después de un desastre deberían ir acompañados por campañas de educación para la monitorización del agua a largo plazo, cadenas de distribución y producción local.
Display omitted
•We measured the spectrum (35–500GHz) of monodeuterated isotopologues of ethanol.•The species measured are C2H5OD, CH3CHDOH, and two geometrical forms of CH2DCH2OH.•The respective ...anti-conformers were analysed with a Watson-S reduction Hamiltonian.•We indicate the range of J and Ka for which this treatment is valid.•The aim is to provide a comprehensive set of predictions for radio astronomy.
The rotational spectra of three mono-substituted deuterium isotopologues of the anti conformer of ethanol have been measured between 35 and 500GHz. One of these, CH2DCH2OH, exists as two distinct conformers according to the position of the deuterium atom with respect to the molecular skeleton. The dataset was constrained for fitting with a standard Watson-S reduction Hamiltonian by rejecting transitions from high-lying states, which appear to be perturbed by the gauche states, and by averaging some small methyl torsional splits. This treatment is compatible with the one we employed for the 13C containing isotopologues of ethanol, and with the needs for a first search for these species in the interstellar medium, in particular in spectra taken by ALMA. For this purpose an appropriate set of predictions is given.
PDF
