Anthropometric criteria for the design of tractor cabs and protection frames.

Improved human-tractor interface designs, such as well-accommodated operator enclosures (i.e. cabs and protection frames) can enhance operator productivity, comfort and safety. This study investigated farm-worker anthropometry and determined the critical anthropometric measures and 3-D feature envelopes of body landmarks for the design of tractor operator enclosures. One hundred agriculture workers participated in the study. Their body size and shape information was registered, using a 3-D full-body laser scanner. Knee height (sitting) and another eight parameters were found to affect the cab-enclosure accommodation rating and multiple anthropometric dimensions interactively affected the steering wheel and gear-handle impediment. A principal component analysis has identified 15 representative human body models for digitally assessing tractor-cab accommodation. A set of centroid coordinates of 34 body landmarks and the 95% confidence semi-axis-length for each landmark location were developed to guide tractor designers in their placement of tractor control components in order to best accommodate the user population. Finally, the vertical clearance (90 cm) for agriculture tractor enclosure in the current SAE International J2194 standard appeared to be too short as compared to the 99th percentile sitting height of male farm workers in this study (100.6 cm) and in the 1994 National Health and Nutrition Examination Survey III database (99.9 cm) and of the male civilian population in the 2002 Civilian American and European Surface Anthropometric Resource database (100.4 cm).

Optimising the performance of a lab-scale tidal flow reed bed system treating agricultural wastewater.

A gravel-based tidal flow reed bed system was operated with three different strategies in order to investigate its optimal performance for the treatment of a high strength agricultural wastewater. According to the three strategies, individual reed beds were saturated and unsaturated with the wastewater for different periods while reasonably stable hydraulic and organic loadings were maintained. Experimental results demonstrated that the system produced the highest pollutant removal efficiencies with a relatively short saturated period and long unsaturated period, highlighting the importance of oxygen transfer into reed bed matrices during the treatment. Significant removals of some major organic and inorganic pollutants were achieved under all three operational conditions. Nitrification was not the major route of ammoniacal-nitrogen removal when the system was under high organic loading. Due to the filtration of suspended solids and the accumulation of biomass, gradual clogging of the reed bed matrices took place, which caused concerns over the long-term efficiency of the tidal flow system.

Assessing decisional balance for smoking cessation among Southeast Asian males in the US.

This study examines the relationship of positive and negative perceptions of smoking to self-reported readiness to quit smoking among Southeast (SE) Asian males of Cambodian, Laotian or Vietnamese descent. In order to investigate this relationship, measures of decisional balance constructs (i.e. the pros and cons of smoking) appropriate for these ethnic groups were developed. Decisional balance was calculated by subtracting the cons from the pros. Following the criteria established by Prochaska and DiClemente, subjects were categorized into four levels of readiness to quit smoking (precontemplation, contemplation, preparation/action and maintenance). The expected pattern of relationship between decisional balance and stages of change included: (1) the cons of smoking being of less importance than the pros of smoking for those smokers in the precontemplation stage, (2) the pros and cons intersecting at the contemplation stage, and (3) the cons being of greater importance than the pros in the later stages of change. The SE Asian men in this study did not exhibit these decisional balance patterns, although mean decisional balance scores for precontemplators and contemplators were significantly more positive than mean scores for those in the preparation/action and maintenance stages. Decisional balance patterns differed across the three ethnic groups included in the sample.

Differential display identification of plunc, a novel gene expressed in embryonic palate, nasal epithelium, and adult lung.

We have identified a novel gene transcript of approximately 1.1 kilobases in length that is expressed in the presumptive nasal epithelium of the mouse embryo. In situ hybridization analysis shows discrete regions of expression associated with the palate, nasal septum, and nasal conchae. This transcript is also expressed strongly in the trachea and bronchi of the adult lung. Screening of a mouse heart cDNA library yielded several overlapping clones to give a continuous sequence of 1113 bases, containing an open reading frame of 278 codons comprising the complete mRNA. No significant homologies with known genes were observed at the nucleotide level; limited amino acid homology with two salivary gland-specific proteins was noted. A search for functionally significant protein motifs revealed consensus sequences for N-glycosylation, protein kinase C and casein kinase phosphorylation, and a leucine zipper. Additionally, we observed a unique amino acid sequence pattern, consisting of the residues Gly-(Leu/Pro/Gln)-(Pro/Leu)-Leu-Pro-Leu, repeated four times near the amino-terminal portion of the protein with two amino acid residues separating the repeats. Based on these observations, we propose that we have identified a new gene, which we call plunc (for palate, lung, and nasal epithelium clone; GenBankTM accession number U69172).

Transformational leadership and the hospice R.N. case manager: a new critical pathway.

This article asserts that in light of changing conditions in the healthcare environment, transformational leadership is the most appropriate leadership style for the hospice registered nurse case manager. The author defines transformational leadership and, tracing from early leadership theories, demonstrates how the transformational-transactional leadership paradigm emerged from preceding leadership theories. The components of transformational leadership--transformational behavior and transformational characteristics--are linked to hospice theory and hospice-specific nursing practices. The expanding role of the hospice R.N. case manager is addressed in light of transformational leadership and culture building. Specific actions are proposed in the arenas of research, education, and community, corporate, and legislative involvement.

Cross-talk between signaling pathways in murine embryonic palate cells: effect of TGF beta and cAMP on EGF-induced DNA synthesis.

Signaling pathways utilized by EGF, cAMP, and TGF beta have been demonstrated to play critical roles in normal palate development. Stimulation of these pathways has been shown in palate cells and numerous other systems to affect cell growth. Because proper regulation of cell growth is critical to palate development, we speculate that fine regulation of palatal cell growth may be accomplished through crosstalk between these signaling pathways. We therefore set out to determine the effects of cAMP and TGF beta on EGF-induced cell proliferation in murine embryonic palate cells. We found that both TGF beta and cAMP inhibited the proliferative response of cells to treatment with EGF, whereas H89, a serine/ threonine protein kinase inhibitor with selectivity towards cAMP-dependent protein kinase, increased the cells' proliferative response to EGF. Genestein, a selective inhibitor of tyrosine kinases, at high doses abrogated the cells' proliferative response to EGF, confirming that EGF's ability to induce cell proliferation is critically dependent upon tyrosine kinase activity. Lower doses of genestein, however, actually enhanced cellular response to EGF. The data suggest that both the TGF beta- and cAMP-mediated signaling pathways may be involved in modulation of the effects of EGF on palate cell growth in vivo.

Effects of dexamethasone on the expression of transforming growth factor-beta in mouse embryonic palatal mesenchymal cells.

The central role of TGF-beta in the development of the embryonic palate has been well characterized. TGF-beta inhibits mesenchymal cell proliferation, induces medial edge epithelial cell differentiation, and modulates the expression of extracellular matrix proteins as well as the proteases that act upon them. Mechanisms by which TGF-beta expression itself is regulated are less well understood. Glucocorticoids are recognized in several cellular systems as able to regulate the expression of TGF-beta. This study was therefore designed to examine whether glucocorticoids affect the expression of TGF-beta isoforms in embryonic palatal cells. Based on flow cytometric analysis and viability determination, confluent primary cultures of mouse embryonic palate mesenchymal (MEPM) cells exposed to up to 10(-6) M dexamethasone (dex) exhibited no signs of cytotoxicity after 24 hours of exposure. Northern blot analyses revealed that dexamethasone reduced steady-state mRNA levels of TGF-beta 3 in a dose-dependent manner as early as 4 hours after treatment but had little effect on TGF-beta 1 and TGF-beta 2 expression up to 24 hours of dex exposure. Dex also reduced the synthesis of both latent and mature forms of TGF-beta protein by approximately four-fold as determined by the mink lung epithelial cell growth inhibition bioassay. Assessment of the ratio of mature to latent protein found in conditioned medium of control compared to dex-treated cultures indicated that dexamethasone may reduce the activation of latent TGF-beta to mature biologically active TGF-beta. Dexamethasone inhibited the proliferation of MEPM cells despite the down-regulation of TGF-beta suggesting that dex-induced growth inhibition of MEPM cells is not mediated by TGF-beta. These data suggest that dex modulates TGF-beta signaling pathways directly by down-regulating TGF-beta expression and possibly indirectly by altering the availability of mature TGF-beta necessary to exert its biological effects in the developing palate.

TGF-beta modulates the expression of retinoic acid-induced RAR-beta in primary cultures of embryonic palate cells.

We have previously shown that both transforming growth factor-beta (TGF-beta) and retinoic acid (RA) regulate the expression of cellular retinoic acid binding proteins (CRABP) I and II and TGF-beta 3 mRNAs in primary cultures of murine embryonic palate mesenchymal (MEPM) cells. We now describe additional cross-talk between the RA and TGF-beta signal transduction pathways--the ability of TGF-beta, including the endogenous form(s), to modulate the expression of the nuclear retinoic acid receptor-beta (RAR-beta). Northern blot hybridization revealed that RA induced the expression of RAR-beta mRNA, there being little or no detectable expression in untreated MEPM cells. Induction by 3.3 microM RA was abrogated by simultaneous treatment with TGF-beta 1 (5 ng/ml). TGF-beta 1 alone had no effect on RAR-beta mRNA expression. Determination of RAR-beta mRNA half-life by treatment with actinomycin D indicated that TGF-beta 1 did not alter the stability of RAR-beta mRNA. Conditioned medium (CM) from MEPM cells contained little active TGF-beta protein; heat treatment of the CM dramatically increased the amount of active TGF-beta as assessed by the mink lung epithelial cell bioassay. Furthermore, heat- or acid-activated CM also inhibited CRABP-I and RA-induced RAR-beta expression. The effect of heat-activated conditioned medium could be abrogated with panspecific neutralizing antibodies to TGF-beta, confirming that endogenous TGF-beta is the biologically active factor in heat-activated CM. These results provide evidence for complex interactions between TGF-beta and RA in the regulation of gene expression in embryonic palatal cells and suggest a role for endogenous TGF-beta in the regulation of expression of genes encoding elements of the RA signal transduction pathway.

Lack of specific placental abnormality associated with cocaine use.

Detailed gross and histologic examinations were performed on 13 placentas from pregnancies complicated by maternal cocaine use. There were no characteristic changes in placental morphologic features that would explain the increased morbidity associated with cocaine use. It is likely that cocaine exerts its deleterious effects through acute or chronic pathophysiologic changes rather than alterations in placental architecture.

Acetabular alterations in untreated congenital dysplasia of the hip: computed tomography with multiplanar re-formation and three-dimensional analysis.

The alterations in acetabular morphology that occur in untreated congenital hip dysplasia (CDH) were evaluated in 29 prehistoric and four modern hemipelvis specimens using inspection, sectioning, conventional radiography, CT, and multiplanar re-formation with three-dimensional image reconstruction. Three major patterns of acetabular morphology were recognized, each reflecting a different grade of severity of dysplasia. Type I (positionally unstable or subluxatable) hips were characterized by acetabular deepening with prominent circumferential ossification within the transverse acetabular ligament and everted limbus. Type III (dislocated) hips demonstrated definite false acetabula separated from triangular remnants of the true acetabula by ossified inverted limbi. Type II (subluxated) hips revealed an intermediate pattern, with acetabular elongation and ossification of deformed limbi, but without definite pseudoacetabula. Computed tomography, particularly with three-dimensional analysis, was extremely useful in characterizing the abnormal acetabular morphology of untreated CDH. An awareness of the secondary osseous alterations of this disorder facilitates understanding the spectrum of hip instability and its soft tissue abnormalities.