28 research outputs found
A multimedia mobile phone-based youth smoking cessation intervention: findings from content development and piloting studies
BACKGROUND: While most young people who smoke want to quit, few access cessation support services. Mobile phone-based cessation programs are ideal for young people: mobile phones are the most common means of peer communication, and messages can be delivered in an anonymous manner, anywhere, anytime. Following the success of our text messaging smoking cessation program, we developed an innovative multimedia mobile phone smoking cessation intervention. OBJECTIVE: The aim of the study was to develop and pilot test a youth-oriented multimedia smoking cessation intervention delivered solely by mobile phone. METHODS: Development included creating content and building the technology platform. Content development was overseen by an expert group who advised on youth development principles, observational learning (from social cognitive theory), effective smoking cessation interventions, and social marketing. Young people participated in three content development phases (consultation via focus groups and an online survey, content pre-testing, and selection of role models). Video and text messages were then developed, incorporating the findings from this research. Information technology systems were established to support the delivery of the multimedia messages by mobile phone. A pilot study using an abbreviated 4-week program of video and text content tested the reliability of the systems and the acceptability of the intervention. RESULTS: Approximately 180 young people participated in the consultation phase. There was a high priority placed on music for relaxation (75%) and an interest in interacting with others in the program (40% would read messages, 36% would read a blog). Findings from the pre-testing phase (n = 41) included the importance of selecting "real" and "honest" role models with believable stories, and an interest in animations (37%). Of the 15 participants who took part in the pilot study, 13 (87%) were available for follow-up interviews at 4 weeks: 12 participants liked the program or liked it most of the time and found the role model to be believable; 7 liked the role model video messages (5 were unsure); 8 used the extra assistance for cravings; and 9 were happy with two messages per day. Nine participants (60%) stopped smoking during the program. Some technical challenges were encountered during the pilot study. CONCLUSIONS: A multimedia mobile phone smoking cessation program is technically feasible, and the content developed is appropriate for this medium and is acceptable to our target population. These results have informed the design of a 6-month intervention currently being evaluated for its effectiveness in increasing smoking cessation rates in young people
New resource for population genetics studies on the Australasian intertidal brown alga, Hormosira banksii: isolation and characterization of 15 polymorphic microsatellite loci through next generation DNA sequencing
The Australasian fucoid, Hormosira banksii, commonly known as ‘Neptune’s necklace’ or ‘bubbleweed’ is regarded as an autogenic ecosystem engineer with no functional equivalents. Population declines resulting from climate change and other anthropogenic disturbances pose significant threats to intertidal biodiversity. For effective conservation strategies, patterns of gene flow and population genetic structure across the species distribution need to be clearly understood. We developed a suite of 15 polymorphic microsatellite markers using next generation sequencing of 53–55 individuals from two sites (south-western Victoria and central New South Wales, Australia) and a replicated spatially hierarchical sampling design. We observed low to moderate genetic variation across most loci (mean number of alleles per locus =3.26; mean expected heterozygosity =0.38) with no evidence of individual loci deviating significantly from Hardy-Weinberg equilibrium. Marker independence was confirmed with tests for linkage disequilibrium, and analyses indicated no evidence of null alleles across loci. Independent spatial autocorrelation analyses were performed for each site using multilocus genotypes and different relatedness measures. Both analyses indicated no significant patterns between relatedness and geographic distance, complemented by non-significant Hardy-Weinberg estimates (P < 0.05), suggesting that individuals from each site represent a randomly mating, outcrossing population. A preliminary investigation of population structure indicates that gene flow among sites is limited (FST = 0.49), however more comprehensive sampling is needed to determine the extent of population structure across the species range (>10,000 km). The genetic markers described provide a valuable resource for future population genetic assessments that will help guide conservation planning for H. banksii and the associated intertidal communities
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Consistent phenological shifts in the making of a biodiversity hotspot: the Cape flora
Background
The best documented survival responses of organisms to past climate change on short (glacial-interglacial) timescales are distributional shifts. Despite ample evidence on such timescales for local adaptations of populations at specific sites, the long-term impacts of such changes on evolutionary significant units in response to past climatic change have been little documented. Here we use phylogenies to reconstruct changes in distribution and flowering ecology of the Cape flora - South Africa's biodiversity hotspot - through a period of past (Neogene and Quaternary) changes in the seasonality of rainfall over a timescale of several million years.
Results
Forty-three distributional and phenological shifts consistent with past climatic change occur across the flora, and a comparable number of clades underwent adaptive changes in their flowering phenology (9 clades; half of the clades investigated) as underwent distributional shifts (12 clades; two thirds of the clades investigated). Of extant Cape angiosperm species, 14-41% have been contributed by lineages that show distributional shifts consistent with past climate change, yet a similar proportion (14-55%) arose from lineages that shifted flowering phenology.
Conclusions
Adaptive changes in ecology at the scale we uncover in the Cape and consistent with past climatic change have not been documented for other floras. Shifts in climate tolerance appear to have been more important in this flora than is currently appreciated, and lineages that underwent such shifts went on to contribute a high proportion of the flora's extant species diversity. That shifts in phenology, on an evolutionary timescale and on such a scale, have not yet been detected for other floras is likely a result of the method used; shifts in flowering phenology cannot be detected in the fossil record
Ocean Acidification at High Latitudes: Potential Effects on Functioning of the Antarctic Bivalve Laternula elliptica
Ocean acidification is a well recognised threat to marine ecosystems. High
latitude regions are predicted to be particularly affected due to cold waters
and naturally low carbonate saturation levels. This is of concern for organisms
utilising calcium carbonate (CaCO3) to generate shells or skeletons.
Studies of potential effects of future levels of pCO2 on high latitude
calcifiers are at present limited, and there is little understanding of their
potential to acclimate to these changes. We describe a laboratory experiment
to compare physiological and metabolic responses of a key benthic bivalve, Laternula
elliptica, at pCO2 levels of their natural environment
(430 µatm, pH 7.99; based on field measurements) with those predicted
for 2100 (735 µatm, pH 7.78) and glacial levels (187 µatm, pH
8.32). Adult L. elliptica basal metabolism (oxygen consumption
rates) and heat shock protein HSP70 gene expression levels
increased in response both to lowering and elevation of pH. Expression of
chitin synthase (CHS), a key enzyme involved in synthesis
of bivalve shells, was significantly up-regulated in individuals at pH 7.78,
indicating L. elliptica were working harder to calcify in
seawater undersaturated in aragonite (ΩAr = 0.71),
the CaCO3 polymorph of which their shells are comprised. The different
response variables were influenced by pH in differing ways, highlighting the
importance of assessing a variety of factors to determine the likely impact
of pH change. In combination, the results indicate a negative effect of ocean
acidification on whole-organism functioning of L. elliptica
over relatively short terms (weeks-months) that may be energetically difficult
to maintain over longer time periods. Importantly, however, the observed changes
in L. elliptica CHS gene expression provides evidence for
biological control over the shell formation process, which may enable some
degree of adaptation or acclimation to future ocean acidification scenarios
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Data from: A single panmictic population of endemic red crabs, Gecarcoidea natalis, on Christmas Island with high levels of genetic diversity
The red crab, Gecarcoidea natalis, is endemic to Christmas Island in the Indian Ocean and largely responsible for shaping the unique ecosystem found throughout the island’s rainforests. However, the introduction and establishment of supercolonies of the highly invasive yellow crazy ant, Anoplolepis gracilipes, has decimated red crab numbers over the last several decades. This poses a significant risk to the future conservation of G. natalis and consequently threatens the integrity of the unique island ecosystem. Here we undertook a population genetic analysis of G. natalis using a combination of 11 microsatellite markers and sequencing of the mitochondrial cytochrome oxidase subunit I gene from samples collected on Christmas Island as well as a single location from North Keeling Island (located approximately 900 km west of Christmas Island). The genetic results indicate that G. natalis is a single panmictic population on Christmas Island, with no spatial genetic structure or restricted gene flow apparent between sampled locations. Further, G. natalis from North Keeling Island are not genetically distinct and are recent immigrants from Christmas Island. The effective population size of G. natalis has likely remained large and stable on Christmas Island throughout its evolutionary history with relatively moderate to high levels of genetic diversity in microsatellite loci and mitochondrial haplotypes assessed in this study. For management purposes G. natalis can be considered a single panmictic population, which should simplify conservation efforts for the genetic management of this iconic island species
Assessing the cost-efficiency of environmental DNA sampling
International audienceEnvironmental DNA (eDNA) sampling can be a highly sensitive method for detecting aquatic taxa; however, the cost-efficiency of this technique relative to traditional methods has not been rigorously assessed. We show how methods that account for imperfect and stochastic detection can be used to (i) determine the optimal allocation of survey effort with eDNA sampling for a fixed budget (i.e. identify the optimal combination of water samples vs. site visits), and (ii) assess the cost-efficiency of eDNA sampling relative to traditional survey techniques. We illustrate this approach by comparing eDNA sampling and bottle-trapping for an exotic newt species (Lissotriton v. vulgaris) recently detected in Melbourne, Australia. Bottle traps produced much lower detection rates than eDNA sampling, but the cost-efficiency of the two methods can be similar because bottle-trapping is cheaper per sample. The relative cost-efficiency of the two sampling methods was sensitive to the available survey budget, the costs of eDNA primer/probe development and sample processing and the number of positive quantitative PCR assays (qPCRs) used to designate a water sample as positive for newt DNA. Environmental DNA sampling was more cost-efficient than bottle-trapping for small to intermediate budgets when primer/probe development and sample processing costs were low, and 1/4 or 2/4 positive qPCRs were used to label a water sample as positive for newt eDNA. However, bottle traps were generally more cost-efficient than eDNA sampling when primer/probe development and sample processing costs were high, regardless of qPCR threshold or survey budget. Traditional sampling methods may achieve lower detection probabilities compared to eDNA sampling, but the totality of costs can make eDNA sampling less efficient than traditional techniques in some circumstances. Our approach provides a quantitative framework for determining how many water samples and site visits are required to maximize detection probabilities with eDNA sampling, and can calculate the cost-efficiency of any sampling method
SNP and msat datasets
Microsatellite genotypes for broad geographic sampling, and three fine scale replicates as outlined in the paper. Also the 3 SNP datasets derived from alternative parameter settings
Data from: Genetic rescue increases fitness and aids rapid recovery of an endangered marsupial population
Genetic rescue has now been attempted in several threatened species, but the contribution of genetics per se to any increase in population health can be hard to identify. Rescue is expected to be particularly useful when individuals are introduced into small isolated populations with low levels of genetic variation. Here we consider such a situation by documenting genetic rescue in the mountain pygmy possum, Burramys parvus. Rapid population recovery occurred in the target population after the introduction of a small number of males from a large genetically diverged population. Initial hybrid fitness was more than two-fold higher than non-hybrids; hybrid animals had a larger body size, and female hybrids produced more pouch young and lived longer. Genetic rescue likely contributed to the largest population size ever being recorded at this site. These data point to genetic rescue as being a potentially useful option for the recovery of small threatened populations