Intersection Of Axes Research Articles

‘This place is not for children like her’: disability, ambiguous belonging and the claiming of disadvantage in postapartheid South Africa

This paper presents an exploration of my experiences and unique positioning as a blind, White South African woman. It explores the complex intersections of multiple axes of identity in my...

Intersectionality and public health in the field of erotic-affective relationships among adolescents in Colombia

The erotic affective relationships between adolescents are not only influenced by gender, but also by race, age, social class, sexuality and functional diversity, locating people according to the context, in places of privilege, subordination, discrimination and inequities that influence health disease processes. This essay aims to present intersectionality as an analytical tool for the understanding of violence in these relationships, in the understanding of how different situations of oppression and resistance cross the body of people, thus normalizing their relationships. These intersections of axes of subordination in public health become inequities in health, and must be identified and addressed in primary health care programs and public policies against the prevention of violence.

Identification of the Medial Column Line collapse variation is Crucial in Flat Foot Management

Category: Midfoot/Forefoot Introduction/Purpose: The incompetence of both dynamic and static structures in the foot is responsible for acquired pes planus deformity. The aim of this study was to identify the anatomical location of the midfoot break in symptomatic pes planus deformity, and its relationship with other pes planus radiographic foot measurements. Methods: We completed the radiographic evaluation of 75 feet diagnosed with symptomatic pes planus. The break in the medial column line (Meary’s line) was measured on the lateral radiograph at the intersection of the anatomical axis of the talus and the first metatarsal. Pes planus measurements were performed on each the weight-bearing AP and lateral radiographs, including talonavicular coverage angle, talar – first/ second metatarsal angle, talar uncoverage, talocalcaneal angle, Meary’s angle line break, calcaneal and talar inclination, talocalcaneal angle, cuneiform - metatarsal, tarsal joints angles and distances. Due to Gaussian distribution, unpaired t-test and ANOVA tests were used. Results: The medial column line collapse was at the talonavicular joint in 77.3%, naviculocuneiform in 20%, and cuneiform metatarsal in 2.6%. The line angle severity was proportional to the talonavicular coverage angle and talar uncoverage (p 0.001, R2 0.4915 and P 0.003, R2 0.223). On comparison of the 3 line-break groups, the talocalcaneal angle was significantly higher when the line break was at talonavicular joint (P 0.001) although Meary’s angle was not significantly more severe. Conclusion: The apex of the medial column collapse occurs not only at the talonavicular joint but also distal to the spring ligament and tibialis posterior insertion. Foot abduction increases with the increase in the line collapse regardless of the breaking point. Talus flexion is worse if the arch collapse is at the talonavicular joint, suggesting incompetency of the spring ligament. Assessing the apex of deformity is essential to decide the correct operative strategy.

Tectonic observations in the northern Saih Hatat, Sultanate of Oman

The Saih Hatat region, in northeastern Oman, is characterized by a large tectonic window, tectonically overlain during the upper Cretaceous by nappes composed of sedimentary rocks from the Mesozoic Hawasina ocean and the Samail ophiolite. In this window, the autochthonous sedimentary cover of the eastern Arabian Platform from the Late Neoproterozoic to the Cenomanian is well exposed. The oldest of these strata, the Hatat schists, were deformed into a NE-facing fold nappe during the upper Cretaceous. Within the overturned and thrusted lower limb of that fold nappe, we identified three small windows exposing stratigraphically younger Hiyam carbonates and Ordovician sandstone. The structural inventory of the windows and the surrounding area indicates three major tectonic phases. The first deformation led to NNE-SSW trending fold structures which probably formed simultaneously with the major fold nappe of the Hatat schists, followed by the extreme attenuation and thrusting of the lower limb of the fold nappe. The second phase was a gentle folding of the thrust with N-S oriented fold axes and third deformation phase that formed WNW-ESE oriented open folds. The windows are situated in the intersection of anticline axes of these two superposed fold generations and represent a mini basin-and-dome structure with an extension of just 1 km × 1 km.

Steroids, stress and the gut microbiome-brain axis.

It is becoming well established that the gut microbiome has a profound impact on human health and disease. In this review, we explore how steroids can influence the gut microbiota and, in turn, how the gut microbiota can influence hormone levels. Within the context of the gut microbiome-brain axis, we discuss how perturbations in the gut microbiota can alter the stress axis and behaviour. In addition, human studies on the possible role of gut microbiota in depression and anxiety are examined. Finally, we present some of the challenges and important questions that need to be addressed by future research in this exciting new area at the intersection of steroids, stress, gut-brain axis and human health.

Principles for the Construction of a Metrological Complex for Certification of High-Precision Optoelectronic Goniometers

The geometric diagram of a bench for determining the instrument errors of high-precision two-dimensional optoelectronic goniometers is considered. These errors are found by measuring the angles between known spatially fixed reference directions and comparing the values obtained to the sizes of these angles measured by means of autocollimators oriented to a special caliber (calibrating prism) that fixes the point of intersection of the geometric axes of the controlled goniometer. The caliber standard is in the form of a multifaceted prism with reflective surfaces the normals to which form the required geometric diagram in space.

Interseccionalidad del género y mercado de trabajo postfordista

This article analyzes the different oppression and privilege systems related to gender, class or origin, experimented by women who participate in temporary work programs. The empirical data comes from ethnographic research. The proposal is located in the recognition of the difference between women, a topic in contemporary feminist theory. We rely on intersectionality to make visible the multiple discriminations that women perceive in their everyday life, and the intersection of the hierarchical axes in the international labour market.

A photographic technique for quick assessment of mechanical isocenter of a linear accelerator.

Demands for mechanical accuracy of medical linear accelerators are increased due to the stereotactic and modulated rotational treatments. Mechanical inaccuracies affect the size and shape of the mechanical and radiation isocenters. In practice, the mechanical isocenter is defined by the intersection of rotational axes. However, there are no simple tools to check the properties of the mechanical isocenter in 3D. We introduce a new photography-based method for quick and sub-millimeter accurate determination of the mechanical isocenter. The method is based on image-processing algorithm and modified front pointer. The results demonstrate the quick measurement and visualization of the mechanical isocenter.

Gendered study progress in Flemish academic bachelor programmes

Abstract In Flanders (Belgium), less than half the students enrolling in university succeed. Previous research has linked this to students’ gender, socio-economic, migration, and socio-cultural background. However, most Flemish studies focus on study success in the first year of university. Additionally, the research investigates the effects of socio-demographic and educational background of students, but in an additive way without much attention to the intersections of different axes of diversity. In this exploratory study, we want to investigate the relationship between student gender and students’ representation and study progress in academic bachelor programmes and to what extent the gender effect is homogeneous or divergent for different subpopulations of students. We use data from the Flemish Database Higher Education. Findings indicate, firstly, that the humanities show less gender segregation and more social diversity in general than the fields of STEM (sciences, technology, engineering and mathematics) and medicine. Secondly, in general, men tend to take more time to complete the bachelor programme except for middle class students where women are more at risk for study delay.

Miseducating Latina researchers: Challenges and consequences in the field

This article examines how racism in the academy, by virtue of omission of discussions of race and its intercentricity with other forms of subordination, has the potential to endanger Latina researchers conducting fieldwork in familiar and unfamiliar settings. Failure to consider the intersections of race, gender, immigration and other axes of subordination resulted in three incidents of near-violence and intimidation for one Chicana researcher that, while frightening, are instructive for future and current researchers. Arguing that traditional qualitative methods classrooms and texts overlook the particular challenges and risks that Latina and other female researchers of color may face in the field, this article encourages the inclusion of teaching of critical race theory and critical race methodologies when training novice and senior researchers.

포인트 클라우드를 이용한 파이프라인 연결 자동 모델링에 관한 연구

Manual 3D pipeline modeling from LiDAR scanned point cloud data is laborious and time-consuming process. This paper presents a method to extract the pipe, elbow and branch information which is essential to the automatic modeling of the pipeline connection. The pipe geometry is estimated from the point cloud data through the Hough transform and the elbow position is calculated by the medial axis intersection for assembling the nearest pair of pipes. The branch is also created for a pair of pipe segments by estimating the virtual points on one pipe segment and checking for any feasible intersection with the other pipe’s endpoint within the pre-defined range of distance. As a result of the automatic modeling, a complete 3D pipeline model is generated by connecting the extracted information of pipes, elbows and branches.

Aspects of Socioeconomic Exclusion in Kerala, India: Reflections from an Urban Slum

ABSTRACTThis article probes the intersection of spatial, caste, and gender axes of power in shaping contemporary inequalities in Kerala, through mixed-method research in an urban slum. Relying largely on qualitative data, it constructs a history of work in the slum for lower caste men and women against the backdrop of Kerala politics from the 1940s until the present. It examines the role of widening gender gaps, the persistence of secularized caste, and flagging working-class politics and discourse in shaping contemporary socioeconomic exclusion in urban areas.

Influence of tension and release in piped conveyor belt on change of normal contact forces in hexagonal idler housing for pipe conveyor loaded with material

Every kind of transported bulk material influences operational characteristics of the pipe conveyors significantly. Therefore it is necessary so that users of the pipe belt conveyors are able to perform a more detailed investigation and monitoring of these characteristics. Thanks to information concerning the operational characteristics it is possible to analyse durability of the conveyor belt and extent of belt wearing. However, the process of data collection and identification is demanding and expensive on condition that such process would be realised only by means of measuring equipment. Much more effective is obtaining of the needed information using generalized knowledge in the form of graphs. Every operator of the pipe belt conveyor is able to obtain the required information based on known input values using the corresponding graphs. Afterwards, the obtained information can be applied in a real operation. This article deals with determination of the contact force values for a certain type of the conveyor belt. The contact forces can be estimated in the intersection of axis at the individual idler roll positions in dependence on the tension force and in dependence on the filling rate of the cross-sectional area of the piped belt with the material, taking into consideration the performed experimental measurements.

On the selection of gantry and collimator angles for isocenter localization using Winston-Lutz tests.

In Winston‐Lutz (WL) tests, the isocenter of a linear accelerator (linac) is determined as the intersection of radiation central axes (CAX) from multiple gantry, collimator, and couch angles. It is well known that the CAX can wobble due to mechanical imperfections of the linac. Previous studies suggested that the wobble varies with gantry and collimator angles. Therefore, the isocenter determined in the WL tests has a profound dependence on the gantry and collimator angles at which CAX are sampled. In this study, we evaluated the systematic and random errors in the isocenters determined with different CAX sampling schemes. Digital WL tests were performed on six linacs. For each WL test, 63 CAX were sampled at nine gantry angles and seven collimator angles. Subsets of these data were used to simulate the effects of various CAX sampling schemes. An isocenter was calculated from each subset of CAX and compared against the reference isocenter, which was calculated from 48 opposing CAX. The differences between the calculated isocenters and the reference isocenters ranged from 0 to 0.8 mm. The differences diminished to less than 0.2 mm when 24 or more CAX were sampled. Isocenters determined with collimator 0° were vertically lower than those determined with collimator 90° and 270°. Isocenter localization errors in the longitudinal direction (along the axis of gantry rotation) showed a strong dependence on the collimator angle selected. The errors in all directions were significantly reduced when opposing collimator angles and opposing gantry angles were employed. The isocenter localization errors were less than 0.2 mm with the common CAX sampling scheme, which used four cardinal gantry angles and two opposing collimator angles. Reproducibility studies on one linac showed that the mean and maximum variations of CAX during the WL tests were 0.053 mm and 0.30 mm, respectively. The maximal variation in the resulting isocenters was 0.068 mm if 48 CAX were used, or 0.13 mm if four CAX were used. Quantitative results from this study are useful for understanding and minimizing the isocenter uncertainty in WL tests.PACS number: 87.56.Fc

A Novel Method to Evaluate Precision of Optical Implant Impressions with Commercial Scan Bodies-An Experimental Approach.

Optical transfer is realized with system-specific transfer posts (scan bodies) mounted on dental implants or on implant analogs. This study presents a novel algorithm for creation of geometry on the surface of dental implant scan bodies and examines the precision of the optical acquisition of scan bodies and the precision of the position of the screw-tightened scan bodies on dental implant analogs. Scan bodies of two different implant manufacturers (S1, S2), one with a horizontal and two with different conical implant-abutment geometries were screw tightened to implant analogs in stone casts with a 10 Ncm torque. The stone casts were scanned ten times with a dental lab scanner. Each scan body was removed and positioned ten times; after each repositioning, a scan was performed. The cylinder axis of every scan body and the occlusal horizontal scan body surface was virtually reconstructed. At the intersection of the cylinder axis and the horizontal plane a point was marked. The mean deviation of this point in consecutive scans and the angle between the scan body axes in the virtual models were measured, and the standard deviation was calculated. Statistical significance of the results was tested with a Kruskal-Wallis Test and Mann-Whitney U-test for pairwise comparison (p < 0.05). The mean deviation of the angle between two scan bodies was 0.05° (SD 0.04°) (S1) and 0.14° (SD 0.08°) (S2). After detachment and repositioning of the scan bodies the mean deviation was 0.05° (SD 0.03°) (S1) and 0.16° (SD 0.08°) (S2). The mean deviation of the central point was 5.7 μm (SD 3.4 μm) without detachment and 4.9 μm (SD 2.6 μm) after detachment and repositioning (S1). For system S2 the mean deviation of the central point was 13.4 μm (SD 7.2 μm) after repeated scanning and 15 μm (SD 5 μm) after detachment, repositioning, and repeated scanning. The precision of extraoral scanning of scan bodies is dependent on the scan body surface design and geometry. The precision of scanning with an extraoral model scanner differed between the scan body geometries and inter-scan body distances. The precision of dental implant scan body scanning was not significantly influenced by detachment and repositioning of the scan body.

Early postoperative cartilage evaluation by magnetic resonance imaging using T2 mapping after arthroscopic partial medial meniscectomy

PurposeThis study was performed to quantitatively evaluate postoperative changes in cartilage by T2 mapping after arthroscopic partial medial meniscectomy. Material and MethodsThe study enrolled 17 patients with 20 knees that underwent arthroscopic partial medial meniscectomy. MRI was performed preoperatively and at six months postoperatively, with subjects evaluated by T2 mapping of the central part of the medial condyle of the femur in the sagittal plane. Regions of interest (ROIs) were set at 10 points between the point of intersection of the anatomical axis of the femur and the articular surface of the medial condyle and posterior area approximately 90 degrees to the anatomical axis. Pre- and postoperative T2 values at each ROI were evaluated. ResultsPostoperative T2 values were significantly longer than preoperative values at approximately 20, 30, 40, and 50 degrees to the anatomical axis of the femur. The maximum change between pre- and postoperative T2 values was +6.65% at 30 degrees to the anatomical axis. ConclusionsMechanical stress at positions approximately 20, 30, 40, and 50 degrees relative to the anatomical axis of the femur increased soon after arthroscopic medial meniscectomy. These findings indicate the start of degeneration, via disorganization of collagen arrays, of the articular cartilage and increased water content.

Study on cone roller bearing surface roughness improvement and the effect of surface roughness on tapered roller bearing service life

The paper deals with the impact of internal geometry and micro-geometry of functional surfaces of the cone roller bearing on internal resistance—friction of roller bearings. It describes an ideal point of contact at intersection of cone axes and raceway values, as well as the necessary values of micro-geometry, which enable the use of the bearings under the most demanding installations in the automotive industry—in differential gears, or for installation of pinions of differential gears and cog wheels in gearboxes. It describes optimisation (modification) of production of supporting face of the inner ring of the bearing, the purpose of which is to ensure this perfect point of contact, as well as required values of micro-geometry of functional surfaces.

Three-dimensional dynamic analysis of knee joint during gait in medial knee osteoarthritis using loading axis of knee

We recently developed a new method for three-dimensional evaluation of mechanical factors affecting knee joint in order to help identify factors that contribute to the progression of knee osteoarthritis (KOA). This study aimed to verify the clinical validity of our method by evaluating knee joint dynamics during gait. Subjects were 41 individuals (14 normal knees; 8 mild KOAs; 19 severe KOAs). The positions of skin markers attached to the body were captured during gait, and bi-planar X-ray images of the lower extremities were obtained in standing position. The positional relationship between the markers and femorotibial bones was determined from the X-ray images. Combining this relationship with gait capture allowed for the estimation of relative movement between femorotibial bones. We also calculated the point of intersection of loading axis of knee on the tibial proximal surface (LAK point) to analyze knee joint dynamics. Knee flexion range in subjects with severe KOA during gait was significantly smaller than that in those with normal knees (p=0.011), and knee adduction in those with severe KOA was significantly larger than in those with mild KOA (p<0.000). LAK point was locally loaded on the medial compartment of the tibial surface as KOA progressed, with LAK point of subjects with severe KOA rapidly shifting medially during loading response. Local loading and medial shear force were applied to the tibial surface during stance phase as medial KOA progressed. Our findings suggest that our method is useful for the quantitative evaluation of mechanical factors that affect KOA progression.

Development of a Method to Correlate Anatomic Landmarks with CT Data for Biomechanical in Vitro Experiments

Introduction A majority of the biomechanical in-vitro studies depend on virtual coordinate systems. These are in most cases based on anatomic landmarks. Typically, the vertebral body is marked by passive or active markers and tracked with a motion capture. Each vertebra needs to be referenced with a digitizing probe. The precision of this registration and the consecutive orientation of the body coordinate system are mainly depended on distinguishable anatomic landmarks. Hence, referencing of vertebral bodies is quite error prone. Further problems arise if the reference procedure has to be redone during testing process or the anatomic landmarks are not accessible because of the operative procedure or testing set-up. Material and Methods To address the problem of repeatability, we developed a set of small marker screws that have specially designed screw heads ( Fig. 1 ). The spherical tip of the digitizing probe can be fitted into the cutout cone of the screw head with the result that the referenced point is equivalent to the point of intersection of the screw axis and the perpendicular base of the cone. Accordingly, if the screws are firmly attached to the bone, it will be possible to reference the points very reliable. The following steps did this: 1st step: Insertion of three or four marker screws into each vertebral body. The positions can be freely chosen as long as the motion capture system is able to generate a coordinate system. Any interference with the operative procedure or testing setup should be prevented at this point. 2nd step: Performing a CT/MRI scan of the specimen. In most cases, this has to be done to exclude compromising defects anyway and consequently, no extra effort is necessary. 3rd step: Referencing of the body coordinate systems with the aid of the marker screws. This can be repeated during the testing procedure if necessary. 4th step: Completion of the in vitro testing procedure. Results Transformation matrices could correct the virtual shift from the referenced body coordinate systems to the anatomically aligned coordinate systems taken from CT scan. This was done by determination of the marker screw heads in the depicted volume and virtual regeneration of the referenced body coordinate systems from the 3rd step. Then the coordinates for the generation of the anatomically aligned coordinate systems can be obtained. On the basis of the two coordinate systems, a transformation matrix can be calculated to shift data from one system to the other. In consequence, it was possible to apply each transformation matrix to the data set obtained during the in vitro testing procedure to shift it virtually to the respective anatomically aligned coordinate system. Conclusion The presented algorithm facilitates the link between the kinetic data from in vitro testing procedures and the precise anatomical data from 3D imaging. Accordingly, it might help to understand complex motion parameters (e.g., FHA) by plotting them into the 3D volume. [Figure: see text]

Digital pupillometry and centroid shift changes after cataract surgery

To compare postoperative changes in apparent photopic and mesopic pupil size and centration in relation to cornea reflection landmarks after cataract surgery. LaserVision.gr Clinical and Research Eye Institute, Athens, Greece. Prospective consecutive case study. Pupils were imaged for pupil size and corneal vertex location before and 1-month after cataract surgery. Digital analysis of pupil images was used to determine the Cartesian coordinates (nasal-temporal, horizontal axis, superior-inferior, vertical axis) of the first Purkinje reflection point (approximating the corneal intersection of the visual axis [corneal vertex]) to the pupil geometric center (approximating the corneal intersection of the line of sight [corneal apex]). Pupil size changes were measured, and the correlation between vertex-to-apex shift changes and postoperative pupil centroid shift was evaluated. The study evaluated 40 eyes. The pupil size (diameter) change corresponded to a relative reduction of -9.8% for photopic pupils and -9.1% for mesopic pupils; the difference was statistically significant (P = .045 and P = .011, respectively). Also, there was a reduction in the centroid shift (all eyes) from a mean of 0.12 mm preoperatively to 0.05 mm postoperatively as a result of the postoperative minus temporal horizontal difference between the corneal vertex and the apex. Cataract extraction surgery appears to affect pupil size and centration. Specifically, a smaller pupil and less temporal shift were recorded. These data may have clinical relevance in targeted intraoperative intraocular lens centration. Dr. Kanellopoulos is a consultant to Alcon Surgical, Inc., Wavelight Laser Technologie AG, Allergan, Avedro, Inc., and i-Optics Corp. No author has a financial or proprietary interest in any material or method mentioned.