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Biomedical subjects

P S Kidd

Publications and source records attributed to P S Kidd.

At least 19 recordsLinked to original sources
PubMed2006

Bioavailability and plant accumulation of heavy metals and phosphorus in agricultural soils amended by long-term application of sewage sludge.

Amendment of agricultural soils with municipal sewage sludges provides a valuable source of plant nutrients and organic matter. Nevertheless, addition of heavy metals and risks of eutrophication continue to be of concern. Metal behaviour in soils and plant uptake are dependent on the nature of the metal, sludge/soil physico-chemical properties and plant species. A pot experiment was carried out to evaluate plant production and heavy metal uptake, soil heavy metal pools and bioavailability, and soil P pools and possible leaching losses, in agricultural soils amended with sewage sludge for at least 10 years (F20) compared to non-amended soils (control). Sewage sludge application increased soil pH, N, Olsen-extractable-P, DOC and exchangeable Ca, Mg and K concentrations. Total and EDTA-extractable soil concentrations of Cu and Zn were also significantly greater in F20, and soil metal (Cu, Mn and Zn) and P fractionation altered. Compared to the control, in F20 relative amounts of acid-extractable (Mn, Zn), reducible (Mn, Zn) and oxidisable (Cu, Zn) metal fractions were greater, and a dominance of inorganic P forms was observed. Analyses of F20 soil solutions highlighted risks of PO4 and Cu leaching. However, despite the observed increases in metal bioavailability sewage sludge applications did not lead to an increase in plant shoot concentrations (in wild plants or crop species). On the contrary, depending on the plant species, Mn and Zn tissue concentrations were within the deficiency level for most plants.

Biomass↗
PubMed2006

A phytogeochemical study of the Trás-os-Montes region (NE Portugal): possible species for plant-based soil remediation technologies.

Phytoremediation techniques are now considered to be promising alternatives to conventional techniques for the remediation of diffused or moderately contaminated soils. Despite their growing acceptance relatively few plant species have been studied for phytoremediation purposes. Further geobotanical surveys and plant screenings are necessary since these could lead to the identification of additional species with potential value for such applications. Serpentine areas could prove valuable sources of such plants. In this study heavy metal accumulation was determined in the flora associated with ultramafic and non-ultramafic soils of the Trás-os-Montes region of NE Portugal. Study sites were selected to represent a wide range of soil-forming rocks (serpentinized (S), ultrabasic (UB), basic (B) and acid (migmatite, M and schists, SC) rocks) and plant metal accumulation was related to soil metal bioavailability. Nine plant species (representing 7 families) were sampled including the Ni hyperaccumulator Alyssum serpyllifolium subsp. lusitanicum. The greatest metal accumulation, transport (leaf[metal]:root[metal]) and bioaccumulation (leaf[metal]/soil[metal]) was found in four of the non metal-hyperaccumulating species: Cistus ladanifer, Lavandula stoechas, Plantago subulata subsp. radicata and Thymus mastichina. Metal accumulation depended on both the plant species and the edaphic conditions at its provenance. While P. subulata is of less interest due to its low biomass the remaining three species could be of use in phytoremediation technologies such as phytoextraction, and particularly in soils contaminated with Cr, Mn and Zn. These three species are also of economic interest due to their oil and fragrance producing biomass.

Biodegradation, Environmental↗
PubMed2005

Metal extraction by Alyssum serpyllifolium ssp. lusitanicum on mine-spoil soils from Spain.

The efficiency of Alyssum serpyllifolium ssp. lusitanicum (Brassicaceae) for use in phytoextraction of polymetallic contaminated soils was evaluated. A. serpyllifolium was grown on two mine-spoil soils (MS1 and MS2): MS1 is contaminated with Cr (283 mg kg(-1)) and MS2 is moderately contaminated with Cr (263 mg kg(-1)), Cu (264 mg kg(-1)), Pb (1433 mg kg(-1)) and Zn (377 mg kg(-1)). Soils were limed to about pH 6.0 (MS1/Ca and MS2/Ca) or limed and amended with NPK fertilisers (MS1/NPK and MS2/NPK). Biomass was reduced on MS2/Ca due to Cu phytotoxicity. Fertilisation increased biomass by 10-fold on MS1/NPK, but root growth was reduced by 7-fold compared with MS1/Ca. Plants accumulated Mn, Ni and Zn in shoots, and both metal content and transportation were generally greater in MS2 than in MS1. Zinc bioaccumulation factors (BF, shoot([metal])/soil([metal])) were significantly greater in MS2 than in MS1. However, metal yields were greatest in plants grown on MS1/NPK. Concentrations of EDTA-, NH(4)Cl- and Mehlich 3 (M3)-extractable Mn and Zn were greater after plant growth. Concentrations of M3-extractable Cr, Ni, Pb and Zn were increased at the rhizosphere. Sequential extractions showed changes in the metal distribution among different soil fractions after growth. This could reflect the buffering capacity of these soils or the plants' ability to mobilise metals from less plant-available soil pools. Results suggest that A. serpyllifolium could be suitable for phytoextraction uses in polymetallic-contaminated soils, provided Cu concentrations were not phytotoxic. However, further optimisation of growth and metal extraction are required.

Biodegradation, Environmental↗
PubMed2003

Performance and evaluation of small construction safety training simulations.

BACKGROUND: Back- and fall-related injuries occur frequently in construction and are costly in terms of workers' compensation claims and lost productivity. Interventions are needed that address the susceptibility to these injuries. AIMS: The purpose of this study was to develop and test a safety training intervention for small construction companies (</=10 employees) in Kentucky, USA. This paper will focus on the performance and evaluation of these simulation exercises, not their effectiveness in preventing injuries. METHODS: The intervention consisted of six latent-image narrative simulation exercises targeted at prevention of back- or fall-related injuries, which emphasized both the economic impact of injuries and the benefits of individual and organizational prevention strategies. Participants included owner-operators, supervisors and employees. Analyses were completed to determine participant scores on the intervention along with their perceptions of the quality, realism and applicability of the training. RESULTS: Mean pooled performance scores (percentage correct) were 83.3% [standard deviation (SD) = 8.9, n = 143] for three back simulations and 85.2% (SD = 8.9, n = 159) for three fall-related simulations. Mean total evaluation scores (percentage of maximum) were 83.1% (SD = 11.6) and 85.5% (SD = 11.7) for the back and fall simulations, respectively. Quality and realism evaluation scores were significantly higher than scores for applicability to work. CONCLUSION: Simulations were well received as safety training exercises. Given the heterogeneous work classifications found in small construction companies, it may be preferable to target safety intervention content to specific trades rather than aim for generality across trades.

Accidental Falls↗
PubMed2001

Why plants grow poorly on very acid soils: are ecologists missing the obvious?

Factors associated with soil acidity are considered to be limiting for plants in many parts of the world. This work was undertaken to investigate the role of the toxicity of hydrogen (H(+)) which seems to have been underconsidered by ecologists as an explanation of the reduced plant growth observed in very acid soils. Racial differences are reported in plant growth response to increasing acidity in the grass Holcus lanatus L. (Yorkshire-fog) and the tree Betula pendula Roth (Silver Birch). Soils and seeds were collected from four Scottish sites which covered a range of soils from acid (organic and mineral) to more base-rich. The sites and their pH (1:2.5 fresh soil:0.01 M CaCl(2)) were: Flanders Moss (FM), pH 3.2+/-0.03; Kippenrait Glen (KP), pH 4.8+/- 0.05; Kinloch Rannoch (KR), pH 6.1+/-0.16; and Sheriffmuir (SMM), pH 4.3+/-0.11. The growth rates of two races of H. lanatus, FM and KP, and three races of B. pendula (SMM, KP and KR) were measured in nutrient solution cultures at pH 2.0 (H. lanatus only), 3.0, 4.0, 5.0, and 5.6. Results showed races from acid organic soils (FM) were H(+)-tolerant while those from acid mineral soils (SMM) were Al(3+)-tolerant but not necessarily H(+)-tolerant. These results confirmed that populations were separately adapted to H(+) or Al(3+) toxicity and this was dependent upon the soil characteristics at their site of collection. The fact of plant adaptation to H(+) toxicity supports the view that this is an important factor in very acid soils.

Acids↗
PubMed2001

Kentucky's graduated driver licensing program for young drivers: barriers to effective local implementation.

OBJECTIVES: To examine the implementation of graduated driver licensing (GDL) in Kentucky and to use the data collected to recommend actions to enhance the effectiveness of the GDL program. METHODS: Data were acquired from surveys of 700 law enforcement officers and more than 40 judges and from interviews with 100 persons who implement or are affected by Kentucky's GDL program-for example, traffic court judges, licensing clerks, law enforcement officers, insurance agents, driving instructors, parents, and employers of teens. Transcripts from interviews were analyzed using a qualitative data analysis computer program. RESULTS AND CONCLUSIONS: Participants noted a widespread lack of awareness of the night-time driving restriction and a substantial number of young drivers receiving little driving time during the learner permit phase. It appeared that specific GDL provisions can be difficult for judges and law officers to enforce and the penalty of license suspension after several traffic violations may not be a sufficient deterrent. Efforts are needed to increase parental awareness of GDL provisions, GDL purpose, and their teen's traffic violations and to increase parental enforcement of restrictions that are difficult for law enforcement agencies to monitor, such as the night-time driving restriction and the adult supervision requirement.

Accidents, Traffic↗
PubMed2001

Agricultural Disability Awareness and Risk Education (AgDARE) for high school students.

OBJECTIVE: Develop and test a farm health and injury prevention educational intervention for high school agriculture students. SETTING: Twenty one high schools in Kentucky, Iowa, and Mississippi. METHODS: A quasiexperimental crossover design was used to test the effectiveness of two sets of instructional materials designed through participatory action research with agriculture teachers and students. Narrative simulations based on farm work stories and simulations of farm work while students pretended to have a disability were completed in 14 schools (n = 373) over the academic year. Students in seven control schools (n = 417) received no intervention but completed, in the same time frame as students in the treatment schools, demographic surveys and premeasures and post-measures of farm safety attitudes and intent to change safety behaviors. One year after the intervention, 29 students from the treatment group received farm visits to measure their farm safety behaviors. RESULTS: Students engaged in hazardous work on farms. Thirty two were involved in tractor overturns and 11 had received injuries from rotating power take-off mechanisms. One fourth reported hearing problems, and 21% had respiratory symptoms after working in dusty farm surroundings. Students who completed at least two physical and two narrative simulations of the Agricultural Disability Awareness and Risk Education (AgDARE) curriculum showed statistically significant positive changes in farm safety attitude and intent to change behaviors. CONCLUSIONS: Adolescents engage in farm work that places them at risk for injury and illness. The AgDARE curriculum may be an effective and efficient method of teaching farm safety in high school agriculture classes.

Accident Prevention↗
PubMed2001

The role of root exudates in aluminium resistance and silicon-induced amelioration of aluminium toxicity in three varieties of maize (Zea mays L.).

Aluminium (Al) toxicity is widely considered to be the most important growth-limiting factor for plants in strongly acid soils (pH<5.0). The inhibition of root elongation in three varieties of maize (Zea mays L. vars Clavito, HS701b and Sikuani) was followed over the first 48 h of Al treatment, and during the initial 10 h elongation was determined on an hourly basis. The silicon (Si)-induced amelioration of Al toxicity was investigated by pre-treating seedlings for 72 h in nutrient solutions with 1000 microM Si before transfer into solutions with 0, 20 or 50 microM Al (without Si). Plants were either grown in complete low ionic strength nutrient solutions (CNS) or in low salt solutions of 0.4 mM CaCl2 (LSS). In addition, the role of root exudation of organic compounds as a mechanism of Si-induced alleviation of Al toxicity was investigated. Aluminium-induced inhibition of root elongation in the maize var. HS701b was observed within 1 h of Al exposure. After a lag time of at least 8 h, Si-induced alleviation of Al toxicity was observed in this variety when grown in LSS. In the Al-resistant var. Sikuani, Al-resistance was only observed after exposure to 50 microM Al, and not after exposure to 20 microM Al, suggesting that there exists a threshold Al concentration before the mechanisms of Al resistance are activated. Aluminium stimulated root exudation of oxalic acid in all three varieties, but exudate concentrations did not increase with either Al resistance or with Si pretreatment. Aluminium and Si triggered release of catechol and of the flavonoid-type phenolics: catechin, and quercetin. In the Al-resistant variety, Sikuani, Al-exposed plants pretreated with Si exuded up to 15 times more phenolics than those plants not pretreated with Si. The flavonoid-type phenolics, to date unconsidered, appear to play a role in the mechanism(s) of Si-induced amelioration of Al toxicity.

Aluminum↗
PubMed2000

Effects of aluminium on the growth and mineral composition of Betula pendula Roth.

Aluminium (Al) is rhizotoxic and is often present in acidic soils at activities high enough to inhibit root elongation. The objectives of the present study were to assess the level of Al tolerance in different races of Betula pendula Roth (Silver Birch) and to investigate how growth and nutrient acquisition were affected by Al. A solution culture technique was employed which simulated natural soil solutions. Aluminium at low concentrations (2 and 5 mg l(-1)), enhanced the growth of two races of B. pendula originating from soils poor in Al (FM and KP). In contrast, Al, at all concentrations tested, inhibited growth in an Al-sensitive race (KR) whose provenance was a calcareous soil. At concentrations >/=10 mg l(-1), Al reduced growth in FM and KP races, while growth increased with increasing Al (up to 25 mg l(-1)) in the Al-tolerant, SMM, race. Aluminium altered both root and leaf architecture. Low Al concentrations (<5 mg l(-1)) significantly increased leaf expansion, and high concentrations (>25 mg l(-1)) reduced leaf expansion. In the Al-sensitive race, KR, there was a loss of apical dominance, and both lateral and primary roots were stunted and swollen, with increasing Al concentrations. These results demonstrated pronounced racial differences in tolerance to Al by B. pendula that could be predicted from the soil environment of each race.

Aluminum↗
PubMed2000

Repetitive strain injuries in youth.

PURPOSE: To review the anatomic and physiologic considerations in repetitive strain injuries (RSI) in youth in relation to normal growth and development. DATA SOURCES: Extensive review of scientific literature, laws relating to youth labor, and the authors' experience. CONCLUSIONS: Early detection of youth at risk for RSIs is crucial for prevention and treatment. Physical maturity and size are more important than chronological age in the safe performance of work tasks or sports. IMPLICATIONS FOR PRACTICE: Interventions that reduce injury in youth include gradually increasing training load, improving flexibility, and strength, improving biomechanics, and correcting malalignment. Assessments should include tests of flexibility, laxity, and muscle symmetry.

Adolescent↗
PubMed2000

Getting the focus and the group: enhancing analytical rigor in focus group research.

In the literature on focus groups, far more attention has been devoted to how groups are organized and conducted than to issues of analysis. Although exploitation of group dynamics is touted as a virtue of focus groups, there is very little guidance in the literature with respect to how differences between group and individual discourse impact the analysis and interpretation of focus group data. In this article, the authors describe analytical challenges inherent in the interpretation of focus group data and suggest approaches for enhancing the rigor of analysis and the reliability and validity of focus group findings.

Data Interpretation, Statistical↗
PubMed1997

Economic costs of motor vehicle crashes involving teenaged drivers in Kentucky, 1994.

OBJECTIVES: To analyze data from motor vehicle crashes (MVCs) involving teenaged drivers in Kentucky for 1994, and derive cost estimates of these crashes. METHODS: Crash data were obtained from the Kentucky Traffic Accident Facts 1994 Report and the Kentucky Accident Reporting System. The National Highway Traffic Safety Administration's Crash-Cost program was used to generate cost estimates for Kentucky data. RESULTS: Teenaged drivers had significantly higher MVC fatal and non-fatal injury rates than did adult drivers. The deaths rates were 43.6 and 19.0 per 100,000 for teens and adult drivers, respectively. Odds ratios (ORs) were calculated to estimate the relative risk for (1) involvement in an MVC, (2) fatal or incapacitating injury, and (3) fatal injury for teenaged compared with adult drivers. The crude ORs were statistically significant at each age. Cost estimates were calculated on a per person/vehicle basis. A single fatal injury was $642,700. A critical injury was $563,000. In general, unit costs rose with increasing levels of injury severity. For the total number of fatal injuries, costs exceeded $91 million. For non-fatal injuries and property damage only crashes, total costs were $318 million. Overall, the total cost estimate for MVCs involving teenaged drivers was nearly $410 million. CONCLUSIONS: Strategies aimed to reduce the number of MVCs attributed to teenaged drivers should reduce both the number and costs of crash related deaths and injuries. Graduated driver licensing (GDL) systems are one plausible approach toward achieving this goal. By recently enacting a GDL system in Kentucky, it is anticipated that many lives and dollars will be saved.

Accidents, Traffic↗
PubMed1993

Driving practices, risk-taking motivations, and alcohol use among adolescent drivers: a pilot study.

OBJECTIVE: To explore risk-taking motivations, driving practices, and alcohol use in rural adolescent drivers. DESIGN: Descriptive correlational study, that used three self-administered questionnaires: Risk Taking Questionnaire, Driving Practices Questionnaire, and Short Michigan Alcohol Screening Test. METHODS: Test instruments were administered to 23 adolescent drivers, aged 16 to 18 years, recruited by school guidance counselors. RESULTS: Risky driving practices were associated with alcohol use (r = 0.73) and greater risk-taking motivations (r = 0.75). The mean score on the Short Michigan Alcohol Screening Test (4.23) reflected alcoholic tendencies. Male gender was moderately associated with risky driving practice (r = 0.54). CONCLUSION: Drinking alcohol and risky driving may represent a broader risk-taking syndrome. In identifying injury-susceptible individuals, gender may be less useful than identification of driving practices. Injury alone may an indicator of risk-taking behavior, but when injury is combined with alcohol use the index of suspicion increases. Emergency nurses can screen injured adolescents for risk-taking motivations and discuss injury history and perceived injury susceptibility. Awareness is the first step in initiating self-protective measures.

Adolescent↗
PubMed1990

Emergency management of spinal cord injuries.

The emergency nurse must anticipate the presence of SCIs. Spinal cord-injured patients should be considered acutely ill and assessed in a comprehensive manner. The occurrence of a SCI may mask symptoms of underlying pathologic conditions that, if left untreated, are life-threatening. The emergency nurse is in a pivotal role, whether functioning in a prehospital setting or in the ED, to intervene rapidly.

Emergencies↗