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PubMed2000

Evaluation of safety orientation and training programs for reducing injuries in the plumbing and pipefitting industry.

Construction workers are at increased risk for fatal and non-fatal injuries. This study examined the effectiveness of employee orientation and training in reducing injuries among plumbers and pipefitters. We searched the Occupational Safety and Health Administration's "recordable" injury data and "documentable" safety and training records for six plumbing and pipefitting employers in northwestern Ohio. During the period 1996 to 1998, 133 injuries were recorded with the duration of 2,541,432 working hours. The most common types of injuries were cuts, lacerations, and abrasions. The majority of injuries resulted from workers being struck by objects. The injury rate was significantly higher for small companies and longer working hours. No difference was found between traveling and local workers. Seventy-five percent of workers received safety orientations on injury prevention. Among workers who received safety orientations, only 3.4% experienced injuries, compared with 11.1% of workers without orientations. Safety orientations were associated with a significant reduction in injuries (odds ratio, 0.23; 95% confidence interval, 0.15 to 0.35). Proper safety orientation and training could reduce the risks for occupational injuries in construction workers.

Accidents, Occupational↗
PubMed2006

Factors influencing cup orientation in 500 consecutive total hip replacements.

UNLABELLED: We sought to establish the percentage of acetabular components used in total hip arthroplasties that were located outside a presumed safe range of cup orientation. Data were analyzed to assess whether dislocation in this series was different inside and outside that presumed safe zone. We also asked whether acetabular cup orientation depended on patient body mass index, the amount of preoperative acetabular head coverage, the surgeon, or the use of minimally invasive technique. We assessed cup orientation in 500 total hip arthroplasties performed at one institution. Of these 500 total hip arthroplasties, 400 were done using conventional approaches whereas mini-incisions were used in 100. We found 19.8% of cups were oriented outside the presumed safe range for inclination, and 11.2% of cups were oriented outside the presumed safe range for anteversion. Dislocation was not greater in the group with inclination and anteversion outside the presumed safe. Cup orientation was influenced by pre-operative acetabular head coverage, the surgeon, and minimally invasive technique, but not body mass index. Cup variability was greater than expected. It was not confined to one surgeon, but to the entire group of surgeons experienced in doing total hip replacements. Variability points toward continuous refinement in surgical technique and instrumentation to promote consistency in cup placement. LEVEL OF EVIDENCE: Prognostic study, Level IV (case series).

Acetabulum↗
PubMed2000

Simultaneous measurements of mobility, dispersion, and orientation of DNA during steady-field gel electrophoresis coupling a fluorescence recovery after photobleaching apparatus with a fluorescence detected linear dichroism setup.

Orientation of molecules is responsible for the loss of separability during steady-field gel electrophoresis. In this work we develop a technique to measure simultaneously the relevant parameters involved in the separation mechanism: electrophoretic mobility, band broadening, and molecular orientation. To do that we have associated a fluorescence recovery after photobleaching (FRAP) apparatus with a fluorescence detected linear dichroism setup. This coupling allows one to follow the buildup of orientation during the FRAP experiment. Because orientation involves a change in the angular distribution of fluorescence, we have added a fluorescence polarization setup which can be used in parallel with the FRAP and gives an exact value of the steady-state orientation factor. We illustrate the possibilities of these combined experiments by analyzing the coupling of electrophoretic transport and orientation of lambda DNA in 1% agarose gels.

Bacteriophage lambda↗
PubMed2001

Influence of confinement on the orientational phase transitions in the lamellar phase of a block-copolymer melt under shear flow.

In this paper, we incorporate some real-system effects into the theory of orientational phase transitions under shear flow [M. E. Cates and S. T. Milner, Phys. Rev. Lett. 62 1856 (1989) and G. H. Fredrickson, J. Rheol. 38, 1045 (1994)]. In particular, we study the influence of the shear-cell boundaries on the orientation of the lamellar phase. We predict that at low shear rates, the parallel orientation appears to be stable. We show that there is a critical value of the shear rate at which the parallel orientation loses its stability and the perpendicular one appears immediately below the spinodal. We associate this transition with a crossover from the fluctuation to the mean-field behavior. At lower temperatures, the stability of the parallel orientation is restored. We find that the region of stability of the perpendicular orientation rapidly decreases as shear rate increases. This behavior might be misinterpreted as an additional perpendicular to parallel transition recently discussed in literature.

Journal Article↗
PubMed2004

Isotropic-nematic transition in hard-rod fluids: relation between continuous and restricted-orientation models.

We explore models of hard-rod fluids with a finite number of allowed orientations, and construct their bulk phase diagrams within Onsager's second virial theory. For a one-component fluid, we show that the discretization of the orientations leads to the existence of an artificial (almost) perfectly aligned nematic phase, which coexists with the (physical) nematic phase if the number of orientations is sufficiently large, or with the isotropic phase if the number of orientations is small. Its appearance correlates with the accuracy of sampling the nematic orientation distribution within its typical opening angle. For a binary mixture this artificial phase also exists, and a much larger number of orientations is required to shift it to such high densities that it does not interfere with the physical part of the phase diagram.

Journal Article↗
PubMed2006

Selective ionization of oriented nonpolar molecules with asymmetric structure by phase-controlled two-color laser fields.

We report on the selective ionization of oriented nonpolar molecules with asymmetric structure by using phase-controlled two-color omega + 2omega laser pulses with an intensity of 1.0 x 10(13) W/cm(2) (tunneling ionization regime) and a pulse duration of 130 fs. The orientation of 1-bromo-2-chloroethane was monitored by the directional asymmetries of the forward-backward emission in dissociative ionization. The observed direction of orientation clearly confirms that molecular orientation is induced not by dynamic orientation but by selective ionization of oriented molecules, which reflects the structure of the highest occupied molecular orbital. This method can be applied for the vast majority of molecules.

Journal Article↗
PubMed1986

Responses of Adaxial and Abaxial Stomata of Normally Oriented and Inverted Leaves of Vicia faba L. to Light.

Stomatal conductances of normally oriented and inverted leaves were measured as light levels (photosynthetic photon flux densities) were increased to determine whether abaxial stomata of Vicia faba leaves were more sensitive to light than adaxial stomata. Light levels were increased over uniform populations of leaves of plants grown in an environmental chamber. Adaxial stomata of inverted leaves reached maximum water vapor conductances at a light level of 60 micromoles per square meter per second, the same light level at which abaxial stomata of normally oriented leaves reached maximum conductances. Abaxial stomata of inverted leaves reached maximum conductances at a light level of 500 micromoles per square meter per second, the same light level at which adaxial stomata of normally oriented leaves reached maximum conductances. Maximum conductances in both normally oriented and inverted leaves were about 200 millimoles per square meter per second for adaxial stomata and 330 millimoles per square meter per second for abaxial stomata. Regardless of whether leaves were normally oriented or inverted, when light levels were increased to values high enough that upper leaf surfaces reached maximum conductances (about 500 micromoles per square meter per second), light levels incident on lower, shaded leaf surfaces were just sufficient (about 60 micromoles per square meter per second) for stomata of those surfaces to reach maximum conductances. This ;coordinated' stomatal opening on the separate epidermes resulted in total leaf conductances for normally oriented and inverted leaves that were the same at any given light level. We conclude that stomata in abaxial epidermes of intact Vicia leaves are not more sensitive to light than those in adaxial epidermes, and that stomata in leaves of this plant do not respond to light alone. Additional factors in bulk leaf tissue probably produce coordinated stomatal opening on upper and lower leaf epidermes to optimally meet photosynthetic requirements of the whole leaf for CO(2).

Journal Article↗
PubMed2003

Quantitative analysis of adherent cell orientation influenced by strong magnetic fields.

This paper examines the effect of strong magnetic fields on adherent cells. Smooth muscle cells, cultured in 8- or 14-T superconducting magnets for three days, exhibited orientational order parallel to the magnetic field direction. To discuss the process and the mechanism of the orientation, the orientational characteristic of the cell culture was investigated with quantitative measurements: an orientational order parameter and the Fourier transform (FT) analysis. The orientational order parameter indicates the degree of orientation. The value of the parameter was estimated with the FT of microscopic images. The cells cultured under stronger static magnetic fields exhibited stronger ordering, while they showed weaker ordering in the control when they were cultured under a strong magnetic gradient force of 400 T2/m. The ordering was enhanced under uniform strong magnetic fields, while it was not affected or was suppressed by the strong gradient force. We suggest that the cells organize themselves to minimize their diamagnetic torsion stresses, which can be induced in the uniform magnetic fields by the membrane's diamagnetic anisotropy.

Animals↗
PubMed2005

Orientation in manhattan: equiprojective classes and sequential estimation.

The problem of inferring 3D orientation of a camera from video sequences has been mostly addressed by first computing correspondences of image features. This intermediate step is now seen as the main bottleneck of those approaches. In this paper, we propose a new 3D orientation estimation method for urban (indoor and outdoor) environments, which avoids correspondences between frames. The scene property exploited by our method is that many edges are oriented along three orthogonal directions; this is the recently introduced Manhattan world (MW) assumption. The main contributions of this paper are: the definition of equivalence classes of equiprojective orientations, the introduction of a new small rotation model, formalizing the fact that the camera moves smoothly, and the decoupling of elevation and twist angle estimation from that of the compass angle. We build a probabilistic sequential orientation estimation method, based on an MW likelihood model, with the above-listed contributions allowing a drastic reduction of the search space for each orientation estimate. We demonstrate the performance of our method using real video sequences.

Algorithms↗
PubMed2001

The effect of implied orientation derived from verbal context on picture recognition.

Perceptual symbol systems assume an analogue relationship between a symbol and its referent, whereas amodal symbol systems assume an arbitrary relationship between a symbol and its referent. According to perceptual symbol theories, the complete representation of an object, called a simulation, should reflect physical characteristics of the object. Amodal theories, in contrast, do not make this prediction. We tested the hypothesis, derived from perceptual symbol theories, that people mentally represent the orientation of an object implied by a verbal description. Orientation (vertical-horizontal) was manipulated by having participants read a sentence that implicitly suggested a particular orientation for an object. Then recognition latencies to pictures of the object in each of the two orientations were measured. Pictures matching the orientation of the object implied by the sentence were responded to faster than pictures that did not match the orientation. This finding is interpreted as offering support for theories positing perceptual symbol systems.

Adult↗
PubMed2004

A comparison of aesthetic proportions between the Oriental and Caucasian nose.

Differences in aesthetics between the Oriental and Caucasian nose were examined from a cohort of 118 healthy volunteers of which 61 had an Oriental and 57 had a Caucasian racial origin. The oriental nose projected less from the face, and was broader at the intercanthal level (P < 0.001) and the alar base (P < 0.001), but not at the bony base. The oriental nose projected less at all levels: nasion projection (P < 0.001) and tip projection (P < 0.001). The naso-labial angles for the Orientals in this study exhibited a wider range of variation than the Caucasians, with the oriental male exhibiting the most acute angle (average 86.2 degrees ), because of the forward angulation of the upper lip. Many of the average aesthetic parameters obtained from these two cohorts of healthy subjects did not conform to the published aesthetic standards, set out as the ideal goals for rhinoplasty.

Adolescent↗
PubMed1990

Estimation of surface area and length with the orientator.

The orientator is a new technique for the estimation of length and surface density and other stereological parameters using isotropic sections. It is an unbiased, design-based approach to the quantitative study of anisotropic structures such as muscle, myocardium, bone and cartilage. A simple method for the practical generation of such isotropic planes in biological specimens is described. No special technical equipment is necessary. Knowledge of an axis of anisotropy can be exploited to optimize the efficiency. To randomize directions in space, points are selected with uniform probability in a square using various combinations of simple random, stratified random, and systematic random sampling. The point patterns thus produced are mapped onto the surface of a hemisphere. The mapped points define directions of sectional planes in space. The mapping algorithm ensures that these planes are isotropic, hence unbiased estimates of surface and length density can be obtained via the classical stereological formulae. Various implementations of the orientator are outlined: the prototype version, the orientator-generated ortrip, two systematic versions, and the smooth version. Orientator sections can be generated without difficulty in large specimens; we investigated human skeletal muscle, myocardium, placenta, and gut tissue. Slight practical modifications extend the applicability of the method to smaller organs like rat hearts. At the ultrastructural level, a correction procedure for the loss of anisotropic mitochondrial membranes due to oblique orientation relative to the electron beam is suggested. Other potential applications of the orientator in anisotropic structures include the estimation of individual particle surface area with isotropic nucleators, the determination of the connectivity of branching networks with isotropic disectors, and generation of isotropic sections for second-order stereology (three-dimensional pattern analysis).

Animals↗
PubMed1982

Studies on the transmembrane orientation of cytochrome c oxidase in phospholipid vesicles.

We report investigations into the direction of orientation of cytochrome c oxidase in reconstituted vesicles and the factors determining this. Measurement of the enzyme orientation employed two independent techniques: monitoring of the level of haem reduction by membrane-permeant and membrane-impermeant reagents and a kinetic analysis of the reduction of a spin label covalently bound to the oxidase surface. The method of preparation of the oxidase vesicles had a pronounced effect on the enzyme orientation and the two measurement techniques agreed in indicating that the proportion of mitochondrially oriented enzyme was approximately 85% and 50% for vesicles prepared by cholate dialysis and sonication respectively. Our results show that the membrane orientation of the oxidase is determined by interactions between the phospholipid bilayer and the portion of the enzyme embedded therein, as opposed to gross physical constraints. In particular, we demonstrate that the orientation of the oxidase is affected by the fluidity and surface charge of the membrane.

Electron Spin Resonance Spectroscopy↗
PubMed1984

Sidedness of native membrane vesicles of Escherichia coli and orientation of the reconstituted lactose: H+ carrier.

The orientation of the lactose:H+ carrier of Escherichia coli in various preparations of native and reconstituted vesicles is determined with two impermeant, macromolecular probes: antibodies directed against the C-terminal decapeptide of the carrier and carboxypeptidase A (EC 3.4.17.1). Two methods are employed. Method I is based upon the digestion of all accessible and, therefore, presumably external, C termini of the carrier with carboxypeptidase A and detection of the remaining, internal C termini with 125I-labelled anti-(C-terminus) antibody after electrophoresis of the carrier in the presence of sodium dodecyl sulfate and transfer to nitrocellulose filters. Method II is based upon the binding of 125I-labelled anti-(C-terminus) antibody to the external C termini of the carrier in vesicles and the subsequent isolation of bound antibody by centrifugation. The labelled antibodies are calibrated using a preparation of inside-out vesicles prepared by high-pressure lysis of strain T206. The carrier content is determined by substrate binding. Because the C terminus of the carrier is known to reside on the cytoplasmic side of the membrane, these methods can also be used to determine the sidedness of various preparations of membrane vesicles. Spheroplasts are confirmed to contain carrier molecules of a single orientation, corresponding to that in right-side-out vesicles. In contrast, in purified cytoplasmic membrane vesicles and in crude membrane preparations obtained by sonication or by high-pressure lysis, 96% of the C termini are accessible to carboxypeptidase A, even after repeated sonication. This implies that nearly all carrier molecules in these preparations possess an orientation opposite to that in the cell or in right-side-out vesicles. In proteoliposomes containing carrier reconstituted or purified and reconstituted by two different methods, only 48% of the carrier molecules are oriented in the same way as in the cell. Subjecting such proteoliposomes to cycles of freezing and thawing or to sonication results in a reshuffling of carrier molecules between the inside-out and right-side-out populations while maintaining 41% in the right-side-out orientation. Digestion of the C terminus of the carrier with carboxypeptidase A does not alter either galactoside binding or countertransport. Thus carrier molecules of the inside-out orientation cannot be selectively inactivated. Additionally, an antiserum directed against the purified carrier is demonstrated to contain nearly exclusively anti-(C-terminus) antibodies, which can, in principle, be used in Method I.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies↗
PubMed1993

The actin monomers in the ternary gelsolin: 2 actin complex are in an antiparallel orientation.

Gelsolin forms ternary complexes with two actin monomers in the presence of Ca2+, which nucleate actin polymerization and cap the barbed ends of filaments. It has therefore been assumed that the two actins are oriented in a similar manner to the terminal subunits in the genetic helix of F-actin. We have tested this using chemical cross-linking with N,N'-1,4-phenylenedimaleimide. For all conditions tested, we identified as the only cross-linked dimeric species an actin dimer indistinguishable from the lower actin dimer of 86 kDa. This lower dimer was previously identified in the initial phase of actin polymerization and also when actin paracrystals are chemically cross-linked [Millonig, R., Salvo, H. & Aebi, U. (1988) J. Cell Biol. 106, 785-796]. It probably defines a contact between adjacent monomers oriented in an antiparallel orientation. In contrast, when F-actin is cross-linked by the same reagent, an upper dimer of apparent molecular mass 115 kDa is formed, which corresponds to adjacent monomers in the genetic helix. The formation of this upper dimer was specifically inhibited by addition of gelsolin to F-actin. Evidence is presented for a Cys374-Cys374 cross-link in the lower dimer. Isolated lower dimer binds to gelsolin in a 1:1 stoichiometry, but it inhibits nucleation of polymerization by gelsolin. Other gelsolin constructs that bind two actin subunits (e.g. the N-terminal half of the molecule, which has severing and capping but no nucleating activity) also form only lower dimer when cross-linked with N,N'-1,4-phenylenedimaleimide. Only segment 2-6 (gelsolin fragment devoid of the N-terminal segment 1) induces an upper dimer orientation of the two actins under nucleating conditions. Our evidence suggests that the two actins associated with gelsolin are not fixed in the orientation of adjacent subunits in F-actin; instead they have a flexible orientation with respect to each other, which permits cross-linking into a stable antiparallel form that does not correspond to the presumed nucleating conformation.

Actins↗
PubMed2006

Market orientation: a concept for health libraries.

OBJECTIVES: This paper is the result of exploratory research forming part of ongoing study into the value and relevance of market orientation as a strategic option for library managers. The aim of the study is to gain an understanding of the concept of market orientation relative to the health library sector. METHODOLOGY: A focus group was used to gather data from health librarians working at different levels in the sector. The data was coded and categorized by an expert panel and analysed using a taxonomic map developed during the study. RESULTS: Health library professionals define and understand market orientation in the same way as the concept is defined in the management literature. Their understanding of the concept is developing. A greater emphasis is given to some aspects of market orientation than others. CONCLUSIONS: There are implications for further research. Methods used to measure market orientation in other domains are likely to be relevant for libraries. Research should be extended to different sectors to explore any cross-sector differences. Fostering an organizational culture that supports market orientation has implications for service management and development.

Communication↗
PubMed1983

The relationship between orienting tasks and the structure of memory traces--evidence from false recognition.

This article reports two experiments in which the pattern of false recognition is examined following incidental learning involving either semantically or non-semantically oriented processing tasks. Experiment 1 demonstrates that more false recognitions were made to semantic as opposed to non-semantic distractors when the initial orientation was semantic whilst the reverse was found when initial orientation was non-semantic. Experiment 2 replicates this effect and, in addition, shows that false recognition rates to completely unrelated distractors were significantly lower than those made to distractors related to the unspecified dimension in both semantic and non-semantic orienting conditions. The results are seen as supporting the basic assertion of the levels of processing approach by demonstrating that tasks ostensibly addressed to different processing domains give rise to memory traces that differ qualitatively in structure. The results of Expt 2, however, suggest that orienting tasks do not wholly restrict processing to the dimension specified by their overt demands. The failure of some earlier studies to demonstrate a clear relationship between initial orienting task and the pattern of false recognition responses is attributed to methodological problems.

Attention↗
PubMed1975

Variability of the relative preference for stimulus orientation and direction of movement in some units of the cat visual cortex (areas 17 and 18).

1. The responses to visual stimuli of single units in the cortex of cats anaesthetized with pentobarbitone were recorded extracellularly with glass micropipettes. All had receptive field centres more than 5 degrees and most lay between 5 and 20 degrees from the area centralis. Most units were in Area 18 but some were in the corresponding field representation in Area 17. 2. A quantitative method is described in which the visual stimuli (slits or light bars) were presented repetitively by mechanical means in each of four orientations of the stimulus and in two directions of movement for each orientation. The responses were analysed quantitatively and criteria are described for classification of units according to their preference for particular orientations or directions of movement of the stimulus. 3. Some units were studied continuously for up to 2 hr using the quantitative technique. In Area 18, of nineteen units, eighteen showed changes in their preference for direction of stimulus movement and, in seven of eleven units, the orientation preference changed. In Area 17 direction preference changed in eight of nine units and orientation preference in six of seven. In some cases both orientation and direction preference altered. 4. The relationship of these changes to alterations in the 'spontaneous activity' of the cortical units and to variations in the depth of anaesthesia are considered. Neither would appear to be the sole cause of the phenomenon.

Action Potentials↗