1,991 research outputs found
Molecular analysis of Continuous Plankton Recorder samples, an examination of echinoderm larvae in the North Sea
Analysis of the biological time series of plankton samples collected by the Continuous Plankton
Recorder (CPR) in the North Atlantic and North Sea has shown a regime shift in the plankton
in this region. Both the distributions of planktonic organisms and their timing of occurrence in
the seasonal cycle have changed and these changes appear to ref lect global warming. In the
North Sea the planktonic larvae of echinoderms have shown a recent dramatic increase in both
relative and absolute abundance and their seasonal peak of occurrence has advanced by 47 days.
The identity of the echinoderm larvae involved in this change has, however, remained equivocal.
The small size of many organisms like echinoderm larvae combined with incomplete taxonomic
keys hinders their visual identification and their fragility often means that useful morphological
features are damaged during sampling by the CPR. Here, using new molecular methods applied
to CPR samples, we show that planktonic larvae of the benthic Echinocardium cordatum dominate
the North Sea plankton. We argue that since this species benefits from mild winters and warmer
waters their numerical increase in the plankton is consistent with recent climatic changes that
appear to be affecting the wider ecology of this region
Exceptional abundance of the snake pipefish (Entelurus aequoreus) in the north-eastern Atlantic Ocean
Pipefish (Syngnathidae) have occurred with unprecedented frequency in Continuous Plankton Recorder (CPR) samples to the west of the British Isles from 2003 to 2005. Identification by mtDNA sequencing established that they were snake pipefish, Entelurus aequoreus. The geographical range of the records were from the outer continental shelf of the Celtic Sea and north-west of Ireland to the mid-Atlantic Ridge between 40° and 57°N, with the greatest abundance near the shelf edge and adjacent oceanic waters south of Ireland and west of Brittany. There were records in every month from February to November but most were in late spring and summer. A proposed mechanism for the increase in abundance of the species is that recent climate change has had beneficial impacts on the reproduction of adults and the survival of larvae and juveniles
Exceptional abundance of the snake pipefish (Entelurus aequoreus) in the north-eastern Atlantic Ocean
Pipefish (Syngnathidae) have occurred with unprecedented frequency in Continuous Plankton Recorder (CPR) samples to the west of the British Isles from 2003 to 2005. Identification by mtDNA sequencing established that they were snake pipefish, Entelurus aequoreus. The geographical range of the records were from the outer continental shelf of the Celtic Sea and north-west of Ireland to the mid-Atlantic Ridge between 40° and 57°N, with the greatest abundance near the shelf edge and adjacent oceanic waters south of Ireland and west of Brittany. There were records in every month from February to November but most were in late spring and summer. A proposed mechanism for the increase in abundance of the species is that recent climate change has had beneficial impacts on the reproduction of adults and the survival of larvae and juveniles
Drug resistance in non-B subtype HIV-1: Impact of HIV-1 reverse transcriptase inhibitors
Human immunodeficiency virus (HIV) causes approximately 2.5 million new infections every year, and nearly 1.6 million patients succumb to HIV each year. Several factors, including cross-species transmission and error-prone replication have resulted in extraordinary genetic diversity of HIV groups. One of these groups, known as group M (main) contains nine subtypes (A-D, F-H and J-K) and causes ∼95% of all HIV infections. Most reported data on susceptibility and resistance to anti-HIV therapies are from subtype B HIV infections, which are prevalent in developed countries but account for only ∼12% of all global HIV infections, whereas non-B subtype HIV infections that account for ∼88% of all HIV infections are prevalent primarily in low and middle-income countries. Although the treatments for subtype B infections are generally effective against non-B subtype infections, there are differences in response to therapies. Here, we review how polymorphisms, transmission efficiency of drug-resistant strains, and differences in genetic barrier for drug resistance can differentially alter the response to reverse transcriptase-targeting therapies in various subtypes
Ecology: a prerequisite for malaria elimination and eradication
* Existing front-line vector control measures, such as insecticide-treated nets and residual sprays, cannot break the transmission cycle of Plasmodium falciparum in the most intensely endemic parts of Africa and the Pacific
* The goal of malaria eradication will require urgent strategic investment into understanding the ecology and evolution of the mosquito vectors that transmit malaria
* Priority areas will include understanding aspects of the mosquito life cycle beyond the blood feeding processes which directly mediate malaria transmission
* Global commitment to malaria eradication necessitates a corresponding long-term commitment to vector ecolog
Evaluating VERT as a radiotherapy plan evaluation tool: comparison with treatment planning software
AbstractIntroduction:The virtual environment for radiotherapy training (VERT) helps students to gain technical skills and understanding of 3D anatomy and dosimetry. It has potential as a tool for treatment plan evaluation, although little formal evidence currently supports this.Aim:This paper reports findings from a plan evaluation workshop that facilitated comparison of VERT plan evaluation tools with those provided by conventional treatment planning software (TPS).Method:Students on a pre-registration Post-Graduate Diploma in Radiotherapy worked in small groups evaluating lung plans using both VERT and Eclipse TPS tools. All students were invited to provide ratings concerning how helpful each modality was for a range of evaluation parameters and preferences for use.Results:Most students (11 out of 14) found the session useful and expressed a desire to use VERT in future plan evaluation. The TPS was perceived to be more helpful with constraint-based evaluation while VERT was more helpful with evaluating plans for clinical set-up and delivery (p &lt; 0·001).Conclusion:Student therapeutic radiographers found VERT to be helpful as a plan evaluation tool alongside standard TPS tools, in particular for clinical set-up and delivery aspects of planning. Future work is ongoing to identify the specific impact of VERT as a plan evaluation tool for both students and qualified planners.</jats:sec
Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia
Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration
Reflective Journaling: A Theoretical Model and Digital Prototype for Developing Resilience and Creativity
Reflection is commonly discussed as a tool for personal and professional development that is becoming increasingly important in today’s global and digital world. In this paper, we propose a model that suggests ways in which reflection, in the form of Reflective Journaling, can support the development of creativity and resilience, which are needed to enable individuals to function effectively in a fast-changing environment. In addition, the model proposes ways in which external support and progress monitoring can be used in conjunction with skills in adaptive resilience and structured creativity, to support the maintenance of reflective journaling as a habit, in the longer term, thus creating virtuous cycles of skills and behaviours that can reinforce each other. Based on our model, and additional user research, we describe the design of a first digital prototype that aims to support the use of Reflective Journaling and to develop creativity and resilience through suggested mechanisms. Initial evaluations of our prototype are positive. It has been well-received by early test users, and has the potential to address all the connections defined. We therefore suggest that the theoretical model can be used to develop digital tools, such as the one included, to help those who wish to develop the habit of reflective journaling, and through that a range of other skills associated with resilience and creative thinking. We see this as a starting point for investigating this potential in more depth
Time preferences and risk aversion: tests on domain differences
The design and evaluation of environmental policy requires the incorporation of time and risk elements as many environmental outcomes extend over long time periods and involve a large degree of uncertainty. Understanding how individuals discount and evaluate risks with respect to environmental outcomes is a prime component in designing effective environmental policy to address issues of environmental sustainability, such as climate change. Our objective in this study is to investigate whether subjects' time preferences and risk aversion across the monetary domain and the environmental domain differ. Crucially, our experimental design is incentivized: in the monetary domain, time preferences and risk aversion are elicited with real monetary payoffs, whereas in the environmental domain, we elicit time preferences and risk aversion using real (bee-friendly) plants. We find that subjects' time preferences are not significantly different across the monetary and environmental domains. In contrast, subjects' risk aversion is significantly different across the two domains. More specifically, subjects (men and women) exhibit a higher degree of risk aversion in the environmental domain relative to the monetary domain. Finally, we corroborate earlier results, which document that women are more risk averse than men in the monetary domain. We show this finding to, also, hold in the environmental domain
Geographic Coincidence of Increased Malaria Transmission Hazard and Vulnerability Occurring at the Periphery of two Tanzanian Villages.
The goal of malaria elimination necessitates an improved understanding of any fine-scale geographic variations in transmission risk so that complementary vector control tools can be integrated into current vector control programmes as supplementary measures that are spatially targeted to maximize impact upon residual transmission. This study examines the distribution of host-seeking malaria vectors at households within two villages in rural Tanzania. Host-seeking mosquitoes were sampled from 72 randomly selected households in two villages on a monthly basis throughout 2008 using CDC light-traps placed beside occupied nets. Spatial autocorrelation in the dataset was examined using the Moran's I statistic and the location of any clusters was identified using the Getis-Ord Gi* statistic. Statistical associations between the household characteristics and clusters of mosquitoes were assessed using a generalized linear model for each species. For both Anopheles gambiae sensu lato and Anopheles funestus, the density of host-seeking females was spatially autocorrelated, or clustered. For both species, houses with low densities were clustered in the semi-urban village centre while houses with high densities were clustered in the periphery of the villages. Clusters of houses with low or high densities of An. gambiae s.l. were influenced by the number of residents in nearby houses. The occurrence of high-density clusters of An. gambiae s.l. was associated with lower elevations while An. funestus was also associated with higher elevations. Distance from the village centre was also positively correlated with the number of household occupants and having houses constructed with open eaves. The results of the current study highlight that complementary vector control tools could be most effectively targeted to the periphery of villages where the households potentially have a higher hazard (mosquito densities) and vulnerability (open eaves and larger households) to malaria infection
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