Portable ladder assessment tool development and validation – Quantifying best practices in the field

Many causes for falls from ladders in construction are related to the user’s activities; however, the extent to which users comply with ladder use best practices is unknown and has not been well quantified before. We developed and tested an audit tool that assesses compliance with best practices guidelines for portable-ladder-use designed for applications in the construction industry. Implemented on a hand-held computer, the assessment tool consisted of a series of check-lists categorized in four groups; ladder condition, setup, moving on a ladder, and completing tasks from a ladder. For these four observational categories, the resulting tool contained 31 and 33 questions for step and extension ladders, respectively. Three individuals trained to use the tool scored a set of photographs and videos depicting 25 ladder conditions, 20 ladder setups, 10 users moving on ladders, and 13 users completing tasks from a ladder for a total of 78 observations. The assessment tool had good agreement across and within raters. For the three raters, agreement ranged from 79% to 97% across the questions. Within one subject, kappa coefficients for the intra-rater reliability ranged from 0.67 to 0.91. The tool offers a practical method to quantify best practices associated with ladder use that can ultimately inform targeted intervention efforts.     

Validity of police-reported alcohol involvement in fatal motor carrier crashes in the United States between 1982 and 2005

Objective

To examine the validity of police-reported alcohol data for drivers involved in fatal motor carrier crashes.

Material and Methods

We determined the availability of blood alcohol concentration (BAC) and police-reported alcohol data on 157,702 drivers involved in fatal motor carrier crashes between 1982 - 2005 using Fatality Analysis and Reporting System (FARS) data. Drivers were categorized as motor carrier drivers if they operated a vehicle with a gross vehicle weight rating of greater than 26,000 pounds. Otherwise, they were classified as non motor carrier drivers. The sensitivity and specificity of police-reported alcohol involvement were estimated for both driver types.

Results

Of the 157,702 drivers, 18% had no alcohol information, 15% had BAC results, 42% had police-reported alcohol data, and 25% had both. Alcohol information varied significantly by driver, crash, and vehicle characteristics. For example, motor carrier drivers were significantly more likely (51%) to have BAC testing results compared to non motor carrier drivers (31%) (p < 0.001). The sensitivity of police-reported alcohol involvement for a BAC level ≥ 0.08 was 83% (95% CI 79%, 86%) for motor carrier drivers and 90% (95% CI 89%, 90%) for non motor carrier drivers. The specificity rates were 96% (95% CI 95%, 96%) and 91% (95% CI 90%, 91%), respectively.

Conclusions

The sensitivity and specificity of police-reported alcohol involvement are reasonably high for drivers involved in fatal motor carrier crashes. Further research is needed to determine the extent to which the accuracy of police-reported alcohol involvement may be overestimated because of verification bias.

Impact on the Industry

Based on the results of this study, the federal government should continue to work with states to strengthen their strategies to increase chemical testing of all drivers involved in fatal crashes.     

The economics of harem maintenance in the sac-winged bat, Saccopteryx bilineata (Emballonuridae)

Saccopteryx bilineata has a polygynous mating system in which males defend females in a harem territory. Harem defense and courtship include energetically costly flight maneuvers and hovering displays. We tested if (1) harem males have a greater field metabolic rate than non-harem males or females and if (2) the field metabolic rate of harem males is correlated with the number of females in a harem territory. We measured the energy budget in 32 S. bilineata with the doubly labeled water method and compared these estimates with behavioral observations in the daytime roost. Among adult bats, field metabolic rate varied with body mass by an exponent of approximately two. We found no significant difference in field metabolic rate or mass-specific field metabolic rate between harem and non-harem males. The mass-specific field metabolic rate of harem-males increased with harem size. The latter finding supports the hypothesis that the energy costs of courtship display and territorial defense influence the energy budget of harem males. Overall, field metabolic rates of S. bilineata were lower than those of similarly sized bats of the temperate zone and only 2.3 times above the basal metabolic rate recorded for this species. We suggest that male S. bilineata did not take advantage of their metabolic capacity because a prudent allocation of energy to activities of harem maintenance is an adaptive strategy for males in this mating system.     

Examining Relationships Between Socioeconomic Factors and Landscape Metrics in the Southern Basin of the Caspian Sea

Socioeconomic forces are not only among the main drivers of landscape dynamics; they are also influenced by landscape patterns. Landscape structure and functions are closely related to natural and social factors. The objective of this study was to investigate the relationships among some human-related factors and landscape ecological metrics as landscape pattern indicators and to identify suitable metrics for modeling these relationships. To this goal, landscape ecological metrics were calculated for each of the 32 counties of Mazandaran and Guilan provinces located in the southern basin of the Caspian Sea using land use/cover maps in class level. Stream network metrics were calculated using a digital elevation model, road density metrics were calculated using map of main roads separately, and significant metrics were selected according to results of correlation tests and factor analysis. The correlations between these metrics and socioeconomic factors were tested, and their relationships were modeled with multiple linear regressions. Significant relationships were found among socioeconomic factors and landscape ecological metrics, and land use/cover data are applicable for modeling socioeconomic factors, especially demographic and employment structure factors. Among the landscape metrics applied in this study, road density, mean patch size, mean nearest neighbor distance, and percentage of a land use/cover class in landscape were important metrics for predicting socioeconomic factors. Our findings indicated that road density metric and percentages of urban class are useful for predicting urban socioeconomic factors and percentage of agriculture and forest classes in the landscape are suitable metrics for predicting rural socioeconomic factors.     

Error propagation in pesticide residue measurements estimated by computational simulations and inter-laboratory sample analysis

An assessment of the error associated with conventional pesticide residue analysis has been conducted based on computer simulations and inter-laboratory residue analysis. Computational simulations were conducted based on (i) typical performance and regulatory acceptance criteria of analytical methods, and (ii) field residue distributions. In addition, field samples with incurred residues were sent to different private laboratories and the results compared. The relative difference in pesticide residues obtained when samples from the same field or produce lot are analyzed at separate laboratories was used to quantify the uncertainty associated with residue analyses performed using common analytical technology, and methods that are in compliance with current regulatory requirements. The study showed that differences of > 100% are common and should be expected when samples from the same crop are analyzed at different laboratories. The results also suggest that the error within residue measurements can be particularly detrimental when a result is reported near the maximum residue limit (MRL).     

Uptake,translocation, and control of trumpet flower (Tecoma stans) with aminocyclopyrachlor

To gain a better understanding of the physiology of the herbicide aminocyclopyrachlor in young plants of trumpet flower, the uptake and translocation were evaluated after the application of herbicide. This was determined by treating individual leaves with formulated herbicides plus ¹⁴C-aminocyclopyrachlor after the application of the formulated herbicide. This experiment used a randomized experimental design with three replications. In addition, field studies were conducted to assess the effectiveness of foliar applications of aminocyclopyrachlor in association with metsulfuton-methyl. The plant absorbed 20% of the herbicide applied. The translocation percentage did not surpass 5% of the total amount applied. Only 1% of the herbicide applied was translocated to the roots. Rate of 40 + 13 g a.i. 100 L^?1 of aminocyclopyrachlor+metsulfuron-methyl was effective to control T. stans.     

Coupling Socioeconomic and Lake Systems for Sustainability: A Conceptual Analysis Using Lake St. Clair Region as a Case Study

Applying sustainability at an operational level requires understanding the linkages between socioeconomic and natural systems. We identified linkages in a case study of the Lake St. Clair (LSC) region, part of the Laurentian Great Lakes system. Our research phases included: (1) investigating and revising existing coupled human and natural systems frameworks to develop a framework for this case study; (2) testing and refining the framework by hosting a 1-day stakeholder workshop and (3) creating a causal loop diagram (CLD) to illustrate the relationships among the systems’ key components. With stakeholder assistance, we identified four interrelated pathways that include water use and discharge, land use, tourism and shipping that impact the ecological condition of LSC. The interrelationships between the pathways of water use and tourism are further illustrated by a CLD with several feedback loops. We suggest that this holistic approach can be applied to other case studies and inspire the development of dynamic models capable of informing decision making for sustainability.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-013-0432-4) contains supplementary material, which is available to authorized users.     

Response to W. Kramer: The human sex odds at birth after the atmospheric atomic bomb tests,after Chernobyl,and in the vicinity of nuclear facilities: comment (doi:10.1007/s11356-011-0644-8)

Introduction

This paper is in response to criticism of our article “The human sex odds at birth after the atmospheric atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities” published in Environ Sci Pollut Res 18(5):697–707, 2011.

Methods

Our findings and methods concerning the disturbed human sex odds at birth have been criticized in this journal for being artifacts of data mining, that the concept of statistical significance was misunderstood, and that confounding factors have not been accounted for. Here, we show that this criticism has no basis. We applied well-established statistical methods to large official data sets, and confounding is less important at the level of secular sex odds trends in aggregated annual figures from countries or continents.

Results and conclusions

Moreover, our results are strengthened by recent findings concerning increased infant death sex odds in Germany and increased Down syndrome prevalence at birth across Europe after Chernobyl. Prompted by our studies, an official investigation in Lower Saxony, Germany, by the “Niedersächsisches Landesgesundheitsamt (NLGA)” confirmed our observation of severely escalated sex odds within 40 km distance from the nuclear storage site in Gorleben, Germany.

     

The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 μg g⁻¹). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time.     

Flame retardants and legacy contaminants in polar bears from Alaska, Canada, East Greenland and Svalbard, 2005-2008

Flame retardants and legacy contaminants were analyzed in adipose tissue from 11 circumpolar polar bear (Ursus maritimus) subpopulations in 2005-2008 spanning Alaska east to Svalbard. Although 37 polybrominated diphenyl ethers (PBDEs), total-(α)-hexabromocyclododecane (HBCD), 2 polybrominated biphenyls (PBBs), pentabromotoluene, pentabromoethylbenzene, hexabromobenzene, 1,2-bis(2,4,6-tribromophenoxy(ethane) and decabromodiphenyl ethane were screened, only 4 PBDEs, total-(α-)HBCD and BB153 were consistently found. Geometric mean ΣPBDE (4.6-78.4 ng/g lipid weight (lw)) and BB153 (2.5-81.1 ng/g lw) levels were highest in East Greenland (43.2 and 39.2 ng/g lipid weight (lw), respectively), Svalbard (44.4 and 20.9 ng/g lw) and western (38.6 and 30.1 ng/g lw) and southern Hudson Bay (78.4 and 81.1 ng/g lw). Total-(α)-HBCD levels (<0.3-41.1 ng/g lw) were lower than ΣPBDE levels in all subpopulations except in Svalbard, consistent with greater European HBCD use versus North American pentaBDE product use. ΣPCB levels were high relative to flame retardants as well as other legacy contaminants and increased from west to east (1797-10,537 ng/g lw). ΣCHL levels were highest among legacy organochlorine pesticides and relatively spatially uniform (765-3477 ng/g lw). ΣDDT levels were relatively low and spatially variable (31.5-206 ng/g lw). However, elevated proportions of p,p'-DDT to ΣDDT in Alaska and Beaufort Sea relative to other subpopulations suggested fresh inputs from vector control use in Asia and/or Africa. Comparing earlier circumpolar polar bear studies, ΣPBDE, total-(α)-HBCD, p,p'-DDE and ΣCHL levels consistently declined, whereas levels of other legacy contaminants did not. International regulations have clearly been effective in reducing levels of several legacy contaminants in polar bears relative to historical levels. However, slow or stalling declines of certain historic pollutants like PCBs and a complex mixture of "new" chemicals continue to be of concern to polar bear health and that of their arctic marine ecosystems.