328 research outputs found
Biological Control of Giant Reed (Arundo donax): Economic Aspects
Arundo donax is a large, invasive weed consuming large quantities of water in the riparian area of the Texas Rio Grande Basin. With water availability a concern to the area, the USDA-ARS is investigating biological control agents to increase available water, creating a benefit to both the region’s economy and society in general.Arundo donax, Giant Reed, Water, Economics, Invasive, Environmental Economics and Policy, Resource /Energy Economics and Policy,
Impact of the biological control agent Tetramesa romana (Hymenoptera: Eurytomidae) on Arundo donax (Poaceae: Arundinoideae) along the Rio Grande River in Texas
Five years post-release of the arundo gall wasp, Tetramesa romana, into the riparian habitats of the lower Rio Grande River, changes in the health of the invasive weed, Arundo donax, or giant reed, have been documented. These changes in plant attributes are fairly consistent along the study area of 558 river miles between Del Rio and Brownsville, TX, and support the hypothesis that the arundo wasp has had a significant impact as a biological control agent. Plant attributes were measured prior to release in 10 quadrats at each of 10 field sites in 2007, and measured again at the same undisturbed sites, 5 years after the release of T. romana, in 2014. Above ground biomass of A. donax decreased on average by 22% across the 10 sites. This decline in biomass was negatively correlated to increased total numbers of T. romana exit holes in main and lateral shoots per site in 2014 compared to 2007. Changes in biomass, live shoot density and shoot lengths, especially the positive effect of galling on main and lateral shoot mortality, appear to be leading to a consistent decline of A. donax. Economically, this reduction in A. donax biomass is estimated to be saving 4.4 million dollars per year in agricultural water. Additional impacts are expected as populations of the wasp increase and as other biological control agents such as the arundo scale, Rhizaspidiotus donacis, become more widespread
Mitigating Predatory Ants Promotes Establishment of Biological Control of Arundo by Arundo Scale in the Cattle Fever Tick Quarantine Zone
Ant collection, identification, and control experiments were conducted to improve the establishment of the arundo scale, Rhizaspidiotus donacis, a biological control agent of Arundo donax, an invasive weed in the riparian habitats along the Rio Grande in Texas. Observational studies indicated R. donacis immatures are preyed upon by a variety of predator insects, especially ants. A survey of the principle ant species was made at sites along the Rio Grande with Arundo donax to help direct biological control strategies. We conclude that uses of ant baits can effectively control the common ant species found in these habitats and improve the establishment of R. donacis
Grasses as suitable targets for classical weed biological control
Grasses are amongst the most abundant and environmentally damaging invasive weeds worldwide. Biological control is frequently employed as a sustainable and cost-effective management strategy for many weeds. However, grasses have not been actively pursued as targets for classical weed biological control due to a perceived lack of sufficiently specialised and damaging natural enemies to use as biological control agents. There are also concerns that the risk posed to economically important crop/pasture species and closely-related native species is too great to consider implementing biological control for invasive grasses. In this paper, we review the literature and demonstrate that grasses can possess suitably host-specific and damaging natural enemies to warrant consideration as potential biological control agents. The risk of grass biological control is no greater than for other weedy taxa if practitioners follow appropriately rigorous risk assessments protocols
Creating corroborated crisis reports from social media data through formal concept analysis
During a crisis citizens reach for their smart phones to report, comment and explore information surrounding the crisis. These actions often involve social media and this data forms a large repository of real-time, crisis related information. Law enforcement agencies and other first responders see this information as having untapped potential. That is, it has the capacity extend their situational awareness beyond the scope of a usual command and control centre. Despite this potential, the sheer volume, the speed at which it arrives, and unstructured nature of social media means that making sense of this data is not a trivial task and one that is not yet satisfactorily solved; both in crisis management and beyond. Therefore we propose a multi-stage process to extract meaning from this data that will provide relevant and near real-time information to command and control to assist in decision support. This process begins with the capture of real-time social media data, the development of specific LEA and crisis focused taxonomies for categorisation and entity extraction, the application of formal concept analysis for aggregation and corroboration and the presentation of this data via map-based and other visualisations. We demonstrate that this novel use of formal concept analysis in combination with context-based entity extraction has the potential to inform law enforcement and/or humanitarian responders about on-going crisis events using social media data in the context of the 2015 Nepal earthquake.
Keywords : formal concept analysis, crisis management, disaster response, visualisation, entity extraction
Implementing nursing best practice guidelines: Impact on patient referrals
<p>Abstract</p> <p>Background</p> <p>Although referring patients to community services is important for optimum continuity of care, referrals between hospital and community sectors are often problematic. Nurses are well positioned to inform patients about referral resources. The objective of this study is to describe the impact of implementing six nursing best practice guidelines (BPGs) on nurses' familiarity with patient referral resources and referral practices.</p> <p>Methods</p> <p>A prospective before and after design was used. For each BPG topic, referral resources were identified. Information about these resources was presented at education sessions for nurses. Pre- and post-questionnaires were completed by a random sample of 257 nurses at 7 hospitals, 2 home visiting nursing services and 1 public health unit. Average response rates for pre- and post-implementation questionnaires were 71% and 54.2%, respectively. Chart audits were completed for three BPGs (n = 421 pre- and 332 post-implementation). Post-hospital discharge patient interviews were conducted for four BPGs (n = 152 pre- and 124 post-implementation).</p> <p>Results</p> <p>There were statistically significant increases in nurses' familiarity with resources for all BPGs, and self-reported referrals to specific services for three guidelines. Higher rates of referrals were observed for services that were part of the organization where the nurses worked. There was almost a complete lack of referrals to Internet sources. No significant differences between pre- and post-implementation referrals rates were observed in the chart documentation or in patients' reports of referrals.</p> <p>Conclusion</p> <p>Implementing nursing BPGs, which included recommendations on patient referrals produced mixed results. Nurses' familiarity with referral resources does not necessarily change their referral practices. Nurses can play a vital role in initiating and supporting appropriate patient referrals. BPGs should include specific recommendations on effective referral processes and this information should be tailored to the community setting where implementation is taking place.</p
Phylogeography of an endangered disjunct herb: long-distance dispersal, refugia and colonization routes
Quaternary glacial cycles appear to have had a consistent role in shaping the genetic diversity and
structure of plant species. Despite the unusual combination of the characteristics of the western Mediterranean–
Macaronesian area, there are no studies that have specifically examined the effects of palaeoclimatic and palaeogeographic
factors on the genetic composition and structure of annual herbs. Astragalus edulis is a disjunct endemic
found in the easternmost Canary Islands and the semi-arid areas of north-eastern Africa and south-eastern Iberian
Peninsula. This endangered species shows no evident adaptations to long-distance dispersal. Amplified fragment
length polymorphism (AFLP) data and plastid DNA sequences were analysed from a total of 360 individuals distributed
throughout the range of this species. The modelled potential distribution of A. edulis under current conditions
was projected over the climatic conditions of the Last Interglacial (130 ka BP) and Last Glacial Maximum (21
ka BP) to analyse changes in habitat suitability and to look for associations between the modelling and genetic
results. Amplified fragment length polymorphism analysis showed clear phylogeographic structure with four distinct
genetic clusters. Approximate Bayesian computation (ABC) models based on plastid DNA sequences indicated a
Middle Pleistocene long-distance dispersal event as the origin of the populations of the Canary Islands. The models
also suggested south-western Morocco as the ancestral area for the species, as well as subsequent colonization of
north-eastern Morocco and the Iberian Peninsula. The data compiled indicated the possibility of the presence of refuge
areas at favourable locations around the High Atlas and Anti-Atlas mountain ranges. Moreover, palaeodistribution
models strongly support the events inferred by ABC modelling and show the potential distribution of the species
in the past, suggesting a putative colonization route.This work has been financed by the Spanish Ministerio
de Ciencia e InnovaciĂłn through the projects CGL2012-
32574 and REN2003-09427, as well as by the Andalusian
ConsejerĂa de InnovaciĂłn, Ciencia y TecnologĂa through
the project RNM1067. The funders had no role in study
design, data collection and analysis, decision to publish
or preparation of the manuscript
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