scholarly journals Euphorbia umbellata (African milk bush).

Author(s):  
Julissa Rojas-Sandoval

Abstract Euphorbia umbellata is a succulent shrub, widely cultivated as an ornamental. It grows in dry open woodland, rocky areas and also in disturbed habitats, where it has escaped from cultivation. Currently it is listed as invasive in India and Cuba, although there is no information available about its environmental impacts in either country. In Australia, it is listed as a minor environmental weed.

2012 ◽  
Vol 60 (6) ◽  
pp. 539 ◽  
Author(s):  
Christine Perrett ◽  
Olusegun O. Osunkoya ◽  
Cameron Clark

Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed in coastal Queensland, Australia. There is a lack of quantitative data on its leaf chemistry and its impact on soil properties. Soils from infested vs uninfested areas, and leaves of M. unguis-cati and three co-occurring vine species (one exotic, two native) were collected at six sites (riparian and non-riparian) in south-eastern Queensland. Effects of invasion status, species, site and habitat type were examined using univariate and multivariate analyses. Habitat type had a greater effect on soil nutrients than on leaf chemistry. Invasion effect of M. unguis-cati on soil chemistry was more pronounced in non-riparian than in riparian habitat. Significantly higher values were obtained in M. unguis-cati infested (vs. uninfested) soils for ~50% of traits. Leaf ion concentrations differed significantly between exotic and native vines. Observed higher leaf-nutrient load (especially nitrogen, phosphorus and potassium) in exotic plants aligns with the preference of invasive plant species for disturbed habitats with higher nutrient input. Higher load of trace elements (aluminium, boron, cadmium and iron) in its leaves suggests that cycling of heavy-metal ions, many of which are potentially toxic at excess level, could be accelerated in soils of M. unguis-cati-invaded landscape. Although inferences from the present study are based on correlative data, the consistency of the patterns across many sites suggests that M. unguis-cati may improve soil fertility and influence nutrient cycling, perhaps through legacy effects of its own litter input.


2020 ◽  
Vol 81 (8) ◽  
pp. 1615-1622 ◽  
Author(s):  
S. Andersson ◽  
M. Rahmberg ◽  
Å. Nilsson ◽  
C. Grundestam ◽  
R. Saagi ◽  
...  

Abstract Changes in dilution of wastewater to a treatment plant due to infiltration or surface runoff can have a great impact on treatment process performance. This paper presents a model-based approach in which realistic influent scenarios are generated and used as inputs to a dynamic plant-wide process model of the wastewater treatment plant. The simulated operation is subsequently evaluated using life-cycle assessment (LCA) to quantify the environmental impacts of the future influent scenarios. The results show that increased infiltration led to higher environmental impact per kg nitrogen removed. The increase in surface runoff had a minor impact.


2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez

Abstract E. indica is primarily listed as an agricultural and environmental weed (Randall, 2012) and is considered a "serious weed" in at least 42 countries (Holm et al., 1979). This species is described as a "dominant weed" especially in farming systems and annual row-crops where it grows vigorously and produces abundant seedlings (Holm et al., 1979). A single plant may produce more than 50,000 small seeds, which can be easily dispersed by wind and water, attached to animal fur and machinery and as a contaminant in soil (Waterhouse, 1993). E. indica invades disturbed habitats in natural areas and the margins of natural forests and grasslands, marshes, stream banks and coastal areas. It is also a common weed along roads, pavements, and powerline corridors (Queensland Department of Primary Industries and Fisheries, 2011). Currently it is listed as invasive in several countries in Europe, Asia, Central and South America, the Caribbean and on many islands in the Pacific Ocean (see Distribution Table for details).


1997 ◽  
Vol 2 (4) ◽  
pp. 1-3
Author(s):  
James B. Talmage

Abstract The AMA Guides to the Evaluation of Permanent Impairment, Fourth Edition, uses the Injury Model to rate impairment in people who have experienced back injuries. Injured individuals who have not required surgery can be rated using differentiators. Challenges arise when assessing patients whose injuries have been treated surgically before the patient is rated for impairment. This article discusses five of the most common situations: 1) What is the impairment rating for an individual who has had an injury resulting in sciatica and who has been treated surgically, either with chemonucleolysis or with discectomy? 2) What is the impairment rating for an individual who has a back strain and is operated on without reasonable indications? 3) What is the impairment rating of an individual with sciatica and a foot drop (major anterior tibialis weakness) from L5 root damage? 4) What is the rating for an individual who is injured, has true radiculopathy, undergoes a discectomy, and is rated as Category III but later has another injury and, ultimately, a second disc operation? 5) What is the impairment rating for an older individual who was asymptomatic until a minor strain-type injury but subsequently has neurogenic claudication with severe surgical spinal stenosis on MRI/myelography? [Continued in the September/October 1997 The Guides Newsletter]


2018 ◽  
Vol 23 (4) ◽  
pp. 9-10
Author(s):  
James Talmage ◽  
Jay Blaisdell

Abstract Pelvic fractures are relatively uncommon, and in workers’ compensation most pelvic fractures are the result of an acute, high-impact event such as a fall from a roof or an automobile collision. A person with osteoporosis may sustain a pelvic fracture from a lower-impact injury such as a minor fall. Further, major parts of the bladder, bowel, reproductive organs, nerves, and blood vessels pass through the pelvic ring, and traumatic pelvic fractures that result from a high-impact event often coincide with damaged organs, significant bleeding, and sensory and motor dysfunction. Following are the steps in the rating process: 1) assign the diagnosis and impairment class for the pelvis; 2) assign the functional history, physical examination, and clinical studies grade modifiers; and 3) apply the net adjustment formula. Because pelvic fractures are so uncommon, raters may be less familiar with the rating process for these types of injuries. The diagnosis-based methodology for rating pelvic fractures is consistent with the process used to rate other musculoskeletal impairments. Evaluators must base the rating on reliable data when the patient is at maximum medical impairment and must assess possible impairment from concomitant injuries.


Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.


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