685 research outputs found
Imported Fire Ant Infestation of Soybean Fields in the Southern United States
Moderate to heavy infestations of the imported fire ants (IFA), Solenopsis invicta Buren and S. richteri Forel, have reduced soybean production in the southern United States. In early surveys of crop damage, Wilson & Eads (1949) attributed a loss of about three percent of the soybean crop in three south Alabama counties to the ants. Adams et al. (1976, 1977) reported that 16.8 to 49.1 kg/ha of soybeans in Georgia and North Carolina were not harvested because of physical interference of S. invicta mounds with combine operation. Subsequent studies in Florida and Mississippi showed that IFA feeding on the germinating seed reduced the plant stand with an ultimate reduction of up to 600 kg/ha in soybean yield (Lofgren and Adams 1981, Adams et al. 1983). Apperson & Powell (1983) found that increased numbers of IFA correlated positively with reduced soybean yield in North Carolin
Imported Fire Ant Infestation of Soybean Fields in the Southern United States
Moderate to heavy infestations of the imported fire ants (IFA), Solenopsis invicta Buren and S. richteri Forel, have reduced soybean production in the southern United States. In early surveys of crop damage, Wilson & Eads (1949) attributed a loss of about three percent of the soybean crop in three south Alabama counties to the ants. Adams et al. (1976, 1977) reported that 16.8 to 49.1 kg/ha of soybeans in Georgia and North Carolina were not harvested because of physical interference of S. invicta mounds with combine operation. Subsequent studies in Florida and Mississippi showed that IFA feeding on the germinating seed reduced the plant stand with an ultimate reduction of up to 600 kg/ha in soybean yield (Lofgren and Adams 1981, Adams et al. 1983). Apperson & Powell (1983) found that increased numbers of IFA correlated positively with reduced soybean yield in North Carolin
Observations of Intercastes in Solenopsis Invicta Buren
The red imported fire ant, Solenopsis invicta Buren, exhibits classical polymorphism, which is defined as the coexistence of 2 or more functionally different castes of the same sex (Wilson 1971). The 2 basic castes are the worker and the female sexuals
Observations on a parasitic nematode (Tetradonematidae) of fire ants, solenopsis (Formicidae), from Mato Grosso.
Parasitic nematodes, Tetradonema sp. (Mermithoidea: Tetradonematidae) were obwserved in the fire ant. Solenopsis invicta Buren, for the first time. Five colonies in a sample of 14 colonies from one site in Mato Grosso were infected. The infection rate among adult workers was 12..5% in one colony and less than 5% in each of the remaining colonies. Adult reproductive males and females, eggs, and juvenile nematodes were observed in the haemocoel of male and worker ants. The infected worker ants often can be recognized by their slightly enlarged gasters, the dorsal scierites of which vable changes in behavior: infected adult males contained normal sperm. An attempt to transmit the nematode to colonies of S. invicta in the United States was unsuccessful.Título em português: Observações sobre um nematóide parasito (Tetradonematidae) da formiga lava-pé, Solenopsis (Formicidae), em Mato Grosso
Influence of Antibiotic Exposure Intensity on the Risk of Clostridioides Difficile Infection
Antibiotics are a strong risk factor for Clostridioides difficile infection (CDI), and CDI incidence is often measured as an important outcome metric for antimicrobial stewardship interventions aiming to reduce antibiotic use. However, risk of CDI from antibiotics varies by agent and dependent on the intensity (i.e., spectrum and duration) of antibiotic therapy. Thus, the impact of stewardship interventions on CDI incidence is variable, and understanding this risk requires a more granular measure of intensity of therapy than traditionally used measures like days of therapy (DOT)
Process for Making Single-Domain Magnetite Crystals
A process for making chemically pure, single-domain magnetite crystals substantially free of structural defects has been invented as a byproduct of research into the origin of globules in a meteorite found in Antarctica and believed to have originated on Mars. The globules in the meteorite comprise layers of mixed (Mg, Fe, and Ca) carbonates, magnetite, and iron sulfides. Since the discovery of the meteorite was announced in August 1996, scientists have debated whether the globules are of biological origin or were formed from inorganic materials by processes that could have taken place on Mars. While the research that led to the present invention has not provided a definitive conclusion concerning the origin of the globules, it has shown that globules of a different but related chemically layered structure can be grown from inorganic ingredients in a multistep precipitation process. As described in more detail below, the present invention comprises the multistep precipitation process plus a subsequent heat treatment. The multistep precipitation process was demonstrated in a laboratory experiment on the growth of submicron ankerite crystals, overgrown by submicron siderite and pyrite crystals, overgrown by submicron magnesite crystals, overgrown by submicron siderite and pyrite. In each step, chloride salts of appropriate cations (Ca, Fe, and Mg) were dissolved in deoxygenated, CO2- saturated water. NaHCO3 was added as a pH buffer while CO2 was passed continuously through the solution. A 15-mL aliquot of the resulting solution was transferred into each of several 20 mL, poly(tetrafluoroethylene)-lined hydrothermal pressure vessels. The vessels were closed in a CO2 atmosphere, then transferred into an oven at a temperature of 150 C. After a predetermined time, the hydrothermal vessels were removed from the oven and quenched in a freezer. Supernatant solutions were decanted, and carbonate precipitates were washed free of soluble salts by repeated decantations with deionized water
Completion of fit notes by GPs: a mixed methods study
Aims: The aim of this study was to investigate the completion of fit notes by UK general practitioners (GPs). A series of actual fit notes issued to employed patients were examined, and their GPs’ reflections and experiences of fit note completion explored.
Methods: A mixed-methods design was used. Data were collected from copies of 94 fit notes issued to employed patients by 11 GPs, and from 86 questionnaires completed by these GPs reflecting on the fit notes they had issued. Face-to-face interviews were then conducted with each GP.
Results: Fit note completion is not meeting expectations for a number of reasons. These include the following: limited knowledge and awareness of the guidance in fit note completion; problems with the fit note format; lack of mandatory training in completing fit notes; lack of incentive to change practice; incomplete implementation of the electronic fit note; GPs’ lack of confidence in, and doubts about the appropriateness of performing this role.
Conclusion: If UK GPs are to continue their contractual responsibility for completing fit notes, further consideration of their education and training needs is urgently required. Weaknesses in the design and format of the fit note and the availability of the electronic version also need to be addressed
The Distributional Effect of Events on Rural and Urban Households in China
International tourism is considered an effective means of economic development. However, the effects of tourism are not evenly distributed between rural and urban households in China. In the wake of significant socioeconomic events, the uneven distribution of the economic effects has huge welfare implications for Chinese households. This study is the first attempt to evaluate the distributional effect of two large, recent, sequential events on China’s rural and urban households. It adopts an innovative approach that combines an econometric model and a two-household computable general equilibrium model. The results show that in terms of welfare, urban households were more adversely affected by the events than rural households. To mitigate the loss of welfare, measures should be taken to continually promote China as a destination and attract tourists after such events occur. Meanwhile, training and education should be made more accessible to rural households to increase their job opportunities
Policy design for the Anthropocene
This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordToday, more than ever, ‘Spaceship Earth’ is an apt metaphor as we chart the boundaries for a safe planet1. Social scientists both analyse why society courts disaster by approaching or even overstepping these boundaries and try to design suitable policies to avoid these perils. Because the threats of transgressing planetary boundaries are global, long-run, uncertain and interconnected, they must be analysed together to avoid conflicts and take advantage of synergies. To obtain policies that are effective at both international and local levels requires careful analysis of the underlying mechanisms across scientific disciplines and approaches, and must take politics into account. In this Perspective, we examine the complexities of designing policies that can keep Earth within the biophysical limits favourable to human life.Stockholm Resilience CentreBECC - Biodiversity and Ecosystem services in a Changing ClimateMistra Carbon Exi
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