The Effect Of Climate Change On The Distributions Of Invasive Plants And Their Associated Biological Control Agents In North America

Climate change has the potential to alter the size, shape, and location of species’ distributions. As a result, the interactions between species are also likely to be impacted as novel species encounter each other and historical community assemblages are broken apart. To quantify the impact of distributional changes as a result of climate change on interacting species, distribution maps were produced for three species of invasive plant and their associated biological control agent at three time periods: current, 2050, and 2080. For each of the future time periods, two distribution maps were created for each species, representing the minimum and maximum emission scenarios considered. The area of the projected future distributions for each species was compared to the current distributions. Percent change in area of distribution was calculated to determine the effect of climate change on the distributions of individual species. The total area of overlap in the distribution of plants and their biological controls for each of the time periods and emission scenarios also was calculated and percent change from the current distribution was used to quantify the effect of climate change on the species interactions. The distributions of the invasive plant species do not follow a consistent trend across models. The distribution of St. Johnswort (Hypericum perforatum Linnaeus, 1753) is expected to increase by 2050, then decrease to an area smaller than the current distribution by 2080. Leafy spurge (Euphorbia esula Linnaeus, 1753) is predicted to have larger distributions by 2080 under both emission scenarios, although only the minimum emission scenario predicts an initial decrease from the current distribution to that expected for 2050. The distribution of yellow toadflax [Linaria vulgaris (Miller, 1768)] is expected to decrease under both emission scenarios by 2080. The distributions of two of the biological control agents (BCAs), Klamath weed beetle [Chrysolina quadrigemina (Suffrian, 1851)] and toadflax moth [Calophasia lunula (Hufnagel, 1766)], are expected to increase by 2080. For both future time periods and emission scenarios, the distribution of leafy spurge hawk moth [Hyles euphorbiae (Linnaeus, 1758)] is expected to decrease from its current area. The area of overlap between two pairs of species (St. Johnswort and the Klamath weed beetle; yellow toadflax and the toadflax moth) is predicted to increase over time. This indicates that the distributions of the invasive species and their associated BCAs will overlap to a greater extent than currently and the BCAs have the potential to remain viable control mechanisms. The area of overlap between leafy spurge and the leafy spurge hawk moth is expected to decrease over time, indicating that the distributions of the species are not likely to respond similarly to climate change. As a result, the leafy spurge hawk moth might not be a suitable control mechanism for leafy spurge in the future. Because of data limitations, the results of this work are applicable to basic understanding of the systems and species involved. However, similar work has the potential to lead to a better understanding of the impact of biotic interactions on invasive and non-native species. In smaller geographic extents, similar research could help prioritize management of invasion by identifying those species that are expected to have increased distributions and escape from their BCA as a result of future climate change

Plant Distribution Data Show Broader Climatic Limits than Expert-Based Climatic Tolerance Estimates

Background Although increasingly sophisticated environmental measures are being applied to species distributions models, the focus remains on using climatic data to provide estimates of habitat suitability. Climatic tolerance estimates based on expert knowledge are available for a wide range of plants via the USDA PLANTS database. We aim to test how climatic tolerance inferred from plant distribution records relates to tolerance estimated by experts. Further, we use this information to identify circumstances when species distributions are more likely to approximate climatic tolerance. Methods We compiled expert knowledge estimates of minimum and maximum precipitation and minimum temperature tolerance for over 1800 conservation plant species from the ‘plant characteristics’ information in the USDA PLANTS database. We derived climatic tolerance from distribution data downloaded from the Global Biodiversity and Information Facility (GBIF) and corresponding climate from WorldClim. We compared expert-derived climatic tolerance to empirical estimates to find the difference between their inferred climate niches (ΔCN), and tested whether ΔCN was influenced by growth form or range size. Results Climate niches calculated from distribution data were significantly broader than expert-based tolerance estimates (Mann-Whitney p values \u3c\u3c 0.001). The average plant could tolerate 24 mm lower minimum precipitation, 14 mm higher maximum precipitation, and 7° C lower minimum temperatures based on distribution data relative to expert-based tolerance estimates. Species with larger ranges had greater ΔCN for minimum precipitation and minimum temperature. For maximum precipitation and minimum temperature, forbs and grasses tended to have larger ΔCN while grasses and trees had larger ΔCN for minimum precipitation. Conclusion Our results show that distribution data are consistently broader than USDA PLANTS experts’ knowledge and likely provide more robust estimates of climatic tolerance, especially for widespread forbs and grasses. These findings suggest that widely available expert-based climatic tolerance estimates underrepresent species’ fundamental niche and likely fail to capture the realized niche

Seasonal Patterns of Microhabitat Selection by a Sub-tropical Whip Spider, Phrynus longipes, in the Luquillo Experimental Forest, Puerto Rico

Phrynus longipes (Pocock 1894) is a top predator among arboreal invertebrates in the Luquillo Mountains of Puerto Rico, but many aspects of its ecology remain poorly understood. We sampled four of the most abundant tree species in the Luquillo Mountains during the dry and wet seasons of 2008 to evaluate microhabitat preferences of this species. In the dry season, P. longipes occurred significantly less frequently on a palm, Prestoea acuminata var. montana (Arecaceae), than the other tree species. Carapace length and the diameter of the tree on which an individual was found were positively correlated, suggesting competition for substrates. Microhabitat selection shifted in the wet season. Individuals occurred as frequently on P. acuminata as on any other species. The seasonal shift in substrate use could result from altered distribution or abundance of prey, an ontogenetic shift in substrate preference or greater competition arising from an increased abundance of P. longipes

Variation of malaria transmission and morbidity with altitude in Tanzania and with introduction of alphacypermethrin treated nets

BACKGROUND: Highland areas with naturally less intense malaria transmission may provide models of how lowland areas might become if transmission was permanently reduced by sustained vector control. It has been argued that vector control should not be attempted in areas of intense transmission. METHODS: Mosquitoes were sampled with light traps, pyrethrum spray and window exit traps. They were tested by ELISA for sporozoites. Incidence of malaria infection was measured by clearing existing infections from children with chlorproguanil-dapsone and then taking weekly blood samples. Prevalence of malaria infection and fever, anaemia and splenomegaly were measured in children of different age groups. All these measurements were made in highland and lowland areas of Tanzania before and after provision of bednets treated with alphacypermethrin. RESULTS: Entomological inoculation rates (EIR) were about 17 times greater in a lowland than a highland area, but incidence of infection only differed by about 2.5 times. Malaria morbidity was significantly less prevalent in the highlands than the lowlands. Treated nets in the highlands and lowlands led to 69–75% reduction in EIR. Malaria morbidity showed significant decline in younger children at both altitudes after introduction of treated nets. In children aged 6–12 the decline was only significant in the highlands CONCLUSIONS: There was no evidence that the health benefits to young children due to the nets in the lowlands were "paid for" by poorer health later in life. Our data support the idea of universal provision of treated nets, not a focus on areas of natural hypo-endemicity

The British HIV Association national clinical audit 2021: Management of HIV and hepatitis C coinfection

Objectives: We aimed to describe clinical policies for the management of people with HIV/hepatitis C virus (HCV) coinfection and to audit routine monitoring and assessment of people with HIV/HCV coinfection attending UK HIV care. Methods: This was a clinic survey and retrospective case-note review. HIV clinics in the UK participated in the audit from May to July 2021 by completing an online questionnaire regarding their clinic's policies for the management of people with HIV/HCV coinfection, and by contributing to a case-note review of people living with HIV with detectable HCV RNA who were under the care of their service. Results: Ninety-five clinics participated in the clinic survey; of these, 15 (15.8%) were regional specialist centres, 19 (20.0%) were HIV services with their own coinfection clinics, 40 (42.1%) were HIV services that referred coinfected individuals to a local hepatology service and 20 (21.1%) were HIV services that referred to a regional specialist centre. Eighty-one clinics provided full caseload estimates; of the approximately 3951 people with a history of HIV/HCV coinfection accessing their clinics, only 4.9% were believed to have detectable HCV RNA, 3.15% of whom were already receiving or approved for direct-acting antiviral (DAA) treatment. In total, 29 (30.5%) of the clinics reported an impact of COVID-19 on coinfection care, including delays or reductions in the frequency of services, monitoring, treatment initiation and appointments, and changes to the way that treatment was dispensed. Case-note reviews were provided for 283 people with detectable HCV RNA from 74 clinics (median age 42 years, 74.6% male, 56.2% HCV genotype 1, 22.3% HCV genotype 3). Overall, 56% had not received treatment for HCV, primarily due to lack of engagement in care (54.7%) and/or being uncontactable (16.4%). Conclusions: Our findings show that the small number of people with HIV with detectable HCV RNA in the UK should mean that it is possible to achieve HCV micro-elimination. However, more work is needed to improve engagement in care for those who are untreated for HCV

Cheatgrass (Bromus tectorum) distribution in the intermountain Western United States and its relationship to fire frequency, seasonality, and ignitions

Cheatgrass (Bromus tectorum) is an invasive grass pervasive across the Intermountain Western US and linked to major increases in fire frequency. Despite widespread ecological impacts associated with cheatgrass, we lack a spatially extensive model of cheatgrass invasion in the Intermountain West. Here, we leverage satellite phenology predictors and thousands of field surveys of cheatgrass abundance to create regional models of cheatgrass distribution and percent cover. We compare cheatgrass presence to fire probability, fire seasonality and ignition source. Regional models of percent cover had low predictive power (34% of variance explained), but distribution models based on a threshold of 15% cover to differentiate high abundance from low abundance had an overall accuracy of 74%. Cheatgrass achieves ≥ 15% cover over 210,000 km2 (31%) of the Intermountain West. These lands were twice as likely to burn as those with low abundance, and four times more likely to burn multiple times between 2000 and 2015. Fire probability increased rapidly at low cheatgrass cover (1–5%) but remained similar at higher cover, suggesting that even small amounts of cheatgrass in an ecosystem can increase fire risk. Abundant cheatgrass was also associated with a 10 days earlier fire seasonality and interacted strongly with anthropogenic ignitions. Fire in cheatgrass was particularly associated with human activity, suggesting that increased awareness of fire danger in invaded areas could reduce risk. This study suggests that cheatgrass is much more spatially extensive and abundant than previously documented and that invasion greatly increases fire frequency, even at low percent cover

Changes in the total fecal bacterial population in individual horses maintained on a restricted diet over 6 weeks

Twelve mature (aged 5–16 years) horses and ponies of mixed breed and type were fed restricted (1.25% BM Dry matter) quantities of one of two fiber based diets formulated to be iso-caloric. Diet 1 comprised of 0.8% body mass (BM) of chaff based complete feed plus 0.45% BM low energy grass hay (the same hay used for both diets). Diet 2 comprised 0.1% BM of a nutrient balancer plus 1.15% BM grass hay. Fecal samples were collected at week 10 and week 16. DNA was extracted and the V1-V2 regions of 16SrDNA were 454-pyrosequenced to investigate the bacterial microbiome of the horse. The two most abundant phyla found in both diets and sampling periods were the Firmicutes and Bacteroidetes. There was a clear reduction in Bacteroidetes with a concordant increase in Firmicutes over time. There was a limited degree of stability within the bacterial community of the hindgut of horses, with 65% of bacteria retained, over a 6 week period whilst on a uniform diet. The presence of a core community defined by being present in all samples (each animal/diet combination) included in the study and being present at 0.1% relative abundance (or greater) was identified. In total 65 operational taxonomic units (OTUs) were identified that fit the definition of core making up 21–28% of the total sequences recovered. As with total population the most abundant phyla were the Bacteroidetes followed by the Firmicutes, however there was no obvious shift in phyla due to period. Indeed, when the relative abundance of OTUs was examined across diets and periods there was no significant effect of diet or period alone or in combination on the relative abundance of the core OTUs

The Sensitivity of Massively Parallel Sequencing for Detecting Candidate Infectious Agents Associated with Human Tissue

Massively parallel sequencing technology now provides the opportunity to sample the transcriptome of a given tissue comprehensively. Transcripts at only a few copies per cell are readily detectable, allowing the discovery of low abundance viral and bacterial transcripts in human tissue samples. Here we describe an approach for mining large sequence data sets for the presence of microbial sequences. Further, we demonstrate the sensitivity of this approach by sequencing human RNA-seq libraries spiked with decreasing amounts of an RNA-virus. At a modest depth of sequencing, viral transcripts can be detected at frequencies less than 1 in 1,000,000. With current sequencing platforms approaching outputs of one billion reads per run, this is a highly sensitive method for detecting putative infectious agents associated with human tissues

Costs of formal and informal care at home for people with dementia: ‘expert panel’ opinions from staff and informal carers

Effective home support in dementia is key in delaying nursing home admission. However, home support is frequently not tailored to the individual needs of people with dementia. Staff allocating home support services may not identify important care needs, which only be recognised by informal carers. The purpose of this study was to explore the balance of informal and formal home support and their associated costs from the perspectives of both informal carers and paid staff. Five case vignettes of people with dementia were designed based on an existing English data set from a European study into transition into long-term care (the RightTimePlaceCare programme), representing 42 per cent of the English sample. In total, 14 informal carers and 14 paid staff were consulted in separate groups, as expert panels, regarding their recommendations for home care services for each vignette. Care recommendations of carers and staff were costed based on nationally available unit costs and compared. Informal carers allocated fewer hours of care than staff. Personal and domestic home care and day care centres were the most frequently recommended formal services by both groups, and some vignettes of people with dementia were recommended for care home admission. The ratio of costs of informal versus formal support was relatively equal for paid staff, yet unbalanced from the perspectives of informal carers with a greater proportion of formal care costs. Recommendations from this study can help shape dementia care to be more tailored to the individual needs of people with dementia and their carers

Strong Stability and Host Specific Bacterial Community in Faeces of Ponies

The horse, as a hindgut fermenter, is reliant on its intestinal bacterial population for efficient diet utilisation. However, sudden disturbance of this population can result in severe colic or laminitis, both of which may require euthanasia. This study therefore aimed to determine the temporal stability of the bacterial population of faecal samples from six ponies maintained on a formulated high fibre diet. Bacterial 16S rRNA terminal restriction fragment length polymorphism (TRFLP) analyses of 10 faecal samples collected from 6 ponies at regular intervals over 72 hour trial periods identified a significant pony-specific profile (P<0.001) with strong stability. Within each pony, a significantly different population was found after 11 weeks on the same diet (P<0.001) and with greater intra-individual similarity. Total short chain fatty acid (SCFA) concentration increased in all ponies, but other changes (such as bacterial population diversity measures, individual major SCFA concentration) were significant and dependent on the individual. This study is the first to report the extent of stability of microbes resident in the intestinal tract as represented with such depth and frequency of faecal sampling. In doing so, this provides a baseline from which future trials can be planned and the extent to which results may be interpreted