Border Locations Research Articles

318P - Margin Assessment in Breast Cancer Lumpectomy Specimens with Infrared Diffuse Reflectance Spectroscopy(Drs)

ABSTRACT Aim: Breast conserving surgery (BCS) is the primary choice of treatment for early stage breast cancer. The number of positive resection margins is still reported 10-20%, emphasizing the need for a tool to discriminate malignant tissue during surgery. Here we investigate whether optical imaging by means of DRS is able to discriminate normal breast tissue from tumor tissue during surgery. Methods: Specimens form thirteen patients undergoing BCS were analyzed. All specimens were processed by the standard protocol of the pathologist. After slicing the lumpectomy specimen, DRS measurements of healthy tissue, malignant tissue and tissue near the border of the tumor were obtained. All measurement locations were photographed to be able to link histopathology with DRS measurements. In addition, two mastectomy specimens were intensively analyzed by performing measurements of the entire surface of the sliced specimen to determine the accuracy of DRS to identify tumor borders. A custom made grid with holes for the probe was laid over the cassette containing the specimen to obtain spectra in a more controlled setting. For each measurement location fat and water content was derived from the spectra with an analytical fitmodel. Results: From the lumpectomy specimens spectra were obtained from 170 locations (34 benign, 27 malignant & 109 border). In healthy tissue a high fat content and low water content was measured whereas in malignant tissue the opposite was seen. The ratio (Fat/Water) calculated from these parameters allowed to discriminate tumor tissue from healthy tissue with a sensitivity of 97% and a specificity of 92%. The ratio calculated for the border locations was in the range between the values found in malignant tissue and healthy tissue. Some border locations resembled tumor tissue whereas others were more similar to healthy tissue. These findings were confirmed with our grid measurements. Conclusions: DRS is able to distinguish healthy tissue from malignant tissue in breast cancer resection specimens. Furthermore, DRS can detect the gradual change of healthy tissue to tumor tissue, and is therefore a promising technique to detect tumor borders during surgery. Especially, since DRS can be applied real time during the surgical procedure. Disclosure: B.H.W. Hendriks and T.M. Bydlon:The author who is affiliated with Philips Research and Philips Healthcare only has financial interests in the subject matter, materials, and equipment, in the sense that he is an employee of Philips. All other authors have declared no conflicts of interest.

Borderland Theory as a Conceptual Framework for Comparative Local US and Canadian History

My book From Great Wilderness to Seaway Towns: A Comparative History of Cornwall, Ontario and Massena, New York, 1784-2001 compared the two towns at different historical moments from 1784 to 2001 by utilizing Oscar Martinez’s borderland theory and argued that the shared experiences of Cornwall and Massena’s residents based on their borderland locations lead them to follow comparable patterns of social and economic development. As former American colonists, both area residents wanted to develop towns identical to their former communities. The founders of Cornwall and Massena and their descendants, therefore, challenged national values and beliefs and developed a distinctive society and culture of their own. In contrast to Seymour Lipset who argued that the organizing principles made the two countries different, my research suggests that Louis Hartz was closer to the mark when he stated “the differences between the two countries are less significant than the traits common to both.” To determine the how the lives of Massena and Cornwall residents’ lives were affected by their border locations, I highlighted key events and experiences that caused these men and women to develop common values and beliefs and adhered to the methodology of local historians.

Modeling policy and agricultural decisions in Afghanistan

Afghanistan is responsible for the majority of the world’s supply of poppy crops, which are often used to produce illegal narcotics like heroin. This paper presents an agent-based model that simulates policy scenarios to characterize how the production of poppy can be dampened and replaced with licit crops over time. The model is initialized with spatial data, including transportation network and satellite-derived land use data. Parameters representing national subsidies, insurgent influence, and trafficking blockades are varied to represent different conditions that might encourage or discourage poppy agriculture. Our model shows that boundary-level interventions, such as targeted trafficking blockades at border locations, are critical in reducing the attractiveness of growing this illicit crop. The principle of least effort implies that interventions decrease to a minimal non-regressive point, leading to the prediction that increases in insurgency or other changes are likely to lead to worsening conditions, and improvements require substantial jumps in intervention resources.

Territorial Dynamics and Stable Home Range Formation for Central Place Foragers

Uncovering the mechanisms behind territory formation is a fundamental problem in behavioural ecology. The broad nature of the underlying conspecific avoidance processes are well documented across a wide range of taxa. Scent marking in particular is common to a large range of terrestrial mammals and is known to be fundamental for communication. However, despite its importance, exact quantification of the time-scales over which scent cues and messages persist remains elusive. Recent work by the present authors has begun to shed light on this problem by modelling animals as random walkers with scent-mediated interaction processes. Territories emerge as dynamic objects that continually change shape and slowly move without settling to a fixed location. As a consequence, the utilisation distribution of such an animal results in a slowly increasing home range, as shown for urban foxes (Vulpes vulpes). For certain other species, however, home ranges reach a stable state. The present work shows that stable home ranges arise when, in addition to scent-mediated conspecific avoidance, each animal moves as a central place forager. That is, the animal's movement has a random aspect but is also biased towards a fixed location, such as a den or nest site. Dynamic territories emerge but the probability distribution of the territory border locations reaches a steady state, causing stable home ranges to emerge from the territorial dynamics. Approximate analytic expressions for the animal's probability density function are derived. A programme is given for using these expressions to quantify both the strength of the animal's movement bias towards the central place and the time-scale over which scent messages persist. Comparisons are made with previous theoretical work modelling central place foragers with conspecific avoidance. Some insights into the mechanisms behind allometric scaling laws of animal space use are also given.

PHENOTYPIC DIFFERENTIATION AT SOUTHERN LIMIT BORDERS: THE CASE STUDY OF TWO FUCOID MACROALGAL SPECIES WITH DIFFERENT LIFE-HISTORY TRAITS1.

Marginal populations are often geographically isolated, smaller, and more fragmented than central populations and may frequently have to face suboptimal local environmental conditions. Persistence of these populations frequently involves the development of adaptive traits at phenotypic and genetic levels. We compared population structure and demographic variables in two fucoid macroalgal species contrasting in patterns of genetic diversity and phenotypic plasticity at their southern distribution limit with a more central location. Models were Ascophyllum nodosum (L.) Le Jol. (whose extreme longevity and generation overlap may buffer genetic loss by drift) and Fucus serratus L. (with low genetic diversity at southern margins). At edge locations, both species exhibited trends in life-history traits compatible with population persistence but by using different mechanisms. Marginal populations of A. nodosum had higher reproductive output in spite of similar mortality rates at all life stages, making edge populations denser and with smaller individuals. In F. serratus, rather than demographic changes, marginal populations differed in habitat, occurring restricted to a narrower vertical habitat range. We conclude that persistence of both A. nodosum and F. serratus at the southern-edge locations depends on different strategies. Marginal population persistence in A. nodosum relies on a differentiation in life-history traits, whereas F. serratus, putatively poorer in evolvability potential, is restricted to a narrower vertical range at border locations. These results contribute to the general understanding of mechanisms that lead to population persistence at distributional limits and to predict population resilience under a scenario of environmental change.

Mapping cortical representations of the rodent forepaw and hindpaw with BOLD fMRI reveals two spatial boundaries

Electrical stimulation of the rat forepaw and hindpaw was employed to study the spatial distribution of BOLD fMRI. Averaging of multiple fMRI sessions significantly improved the spatial stability of the BOLD signal and enabled quantitative determination of the boundaries of the BOLD fMRI maps. The averaged BOLD fMRI signal was distributed unevenly over the extent of the map and the data at the boundaries could be modeled with major and minor spatial components. Comparison of three-dimensional echo-planar imaging (EPI) fMRI at isotropic 300 μm resolution demonstrated that the border locations of the major spatial component of BOLD signal did not overlap between the forepaw and hindpaw maps. Interestingly, the border positions of the minor BOLD fMRI spatial components extended significantly into neighboring representations. Similar results were found for cerebral blood volume (CBV) weighted fMRI obtained using iron oxide particles, suggesting that the minor spatial components may not be due to vascular mislocalization typically associated with BOLD fMRI. Comparison of the BOLD fMRI maps of the forepaw and hindpaw to histological determination of these representations using cytochrome oxidase (CO) staining demonstrated that the major spatial component of the BOLD fMRI activation maps accurately localizes the borders. Finally, 2-3 weeks following peripheral nerve denervation, cortical reorganization/plasticity at the boundaries of somatosensory limb representations in adult rat brain was studied. Denervation of the hindpaw caused a growth in the major component of forepaw representation into the adjacent border of hindpaw representation, such that fitting to two components no longer led to a better fit as compared to using one major component. The border of the representation after plasticity was the same as the border of its minor component in the absence of any plasticity. It is possible that the minor components represent either vascular effects that extend from the real neuronal representations or the neuronal communication between neighboring regions. Either way the results will be useful for studying mechanisms of plasticity that cause alterations in the boundaries of neuronal representations.

Reliability of a Computer-Aided Manual Procedure for Segmenting Optical Coherence Tomography Scans

To assess the within- and between-operator agreement of a computer-aided manual segmentation procedure for frequency-domain optical coherence tomography scans. Four individuals (segmenters) used a computer-aided manual procedure to mark the borders defining the layers analyzed in glaucoma studies. After training, they segmented two sets of scans, an Assessment Set and a Test Set. Each set had scans from 10 patients with glaucoma and 10 healthy controls. Based on an analysis of the Assessment Set, a set of guidelines was written. The Test Set was segmented twice with a ≥1 month separation. Various measures were used to compare test and retest (within-segmenter) variability and between-segmenter variability including concordance correlations between layer borders and the mean across scans (n = 20) of the mean of absolute differences between local border locations of individual scans, MEAN{mean( ΔLBL )}. Within-segmenter reliability was good. The mean concordance correlations values for an individual segmenter and a particular border ranged from 0.999 ± 0.000 to 0.978 ± 0.084. The MEAN{mean( ΔLBL )} values ranged from 1.6 to 4.7 μm depending on border and segmenter. Similarly, between-segmenter agreement was good. The mean concordance correlations values for an individual segmenter and a particular border ranged from 0.999 ± 0.001 to 0.992 ± 0.023. The MEAN{mean( ΔLBL )} values ranged from 1.9 to 4.0 μm depending on border and segmenter. The signed and unsigned average positions were considerably smaller than the MEAN{mean( ΔLBL )} values for both within- and between-segmenter comparisons. Measures of within-segmenter variability were only slightly larger than those of between-segmenter variability. When human segmenters are trained, the within-and between-segmenter reliability of manual border segmentation is quite good. When expressed as a percentage of retinal layer thickness, the results suggest that manual segmentation provides a reliable measure of the thickness of layers typically measured in studies of glaucoma.

Identification of phytogeographical borders using grassland vegetation data

The paper proposes a methodology of phytogeographical regionalisation using grassland vegetation data. The research area is located in the West Carpathians, in volcanic field with adjacent post-tectonic basins and valleys in the Central Slovakia. The applied techniques were variogram modelling, ordinary kriging and lattice wombling. Phi coefficient was used to determine the diagnostic species of proposed phytochoria (fidelity test). The 1978 unevenly distributed grassland polygons that comprised 1071 taxa of vascular plants were the subject of the analyses. Ecological indicator values for temperature (EITs), weighted by species coverage in the Tansley scale in each grassland polygon, were used for the modelling. The gradients in the surface of the indicator value produced by ordinary kriging were analyzed. The steepest gradients indicate the most radical changes in floristic composition typical of border locations.

Marginalization and health: children's asthma on the Texas‐Mexico border

PurposeThe purpose of this paper is to investigate children's vulnerability to asthma and its relationship with marginalized locations. More specifically, the effects of zip code level social predictors on children's asthma and their conditionality on location in the Texas‐Mexico border region are explored. The border region is perhaps the most marginalized in the USA.Design/methodology/approachData for analysis comes from the State of Texas and the US Bureau of the Census. Negative binomial regression models are used to predict asthma hospitalizations using a set of social predictors. Then, interaction effects are used to test if social predictors are conditional on border location.FindingsWithin the state of Texas, location in a metropolitan area, location along the US‐Mexico border, percent Hispanic, percent African American and percent Native American are positive and significant predictors of asthma hospitalizations; social class is negative and significant. The effects of proportion of Hispanics who were foreign born, median year of home construction, and percent of homes with inadequate heating are conditional on a zip code's location relative to the US‐Mexico border, with the slopes being steeper in border locations. Findings in general suggest that locational and social factors intersect in marginalized places (i.e. border regions of Texas) to create vulnerability to asthma hospitalizations.Research limitations/implicationsThis study is conducted solely in the USA.Originality/valueAs sociologists continue to consider space as a factor in health inequalities, this paper demonstrates the utility of considering space as operating at more than one scale.

A vortex axis and vortex core border grid adaptation algorithm

AbstractIn the design process of hydrodynamical and aerodynamical technical applications, the numerical simulation of massively separated vortical flow is crucial for predicting, for example, lift or drag. To obtain reliable numerical results, it is mandatory to accurately predict the physical behavior of vortices. Thus, the dominant vortical flow structures have to be resolved in detail, which requires a local grid refinement and certain adaptation techniques. In this paper, a vortex flow structure adaptation algorithm is presented, which is particularly designed for local grid refinement at vortex axes positions and associated vortex core border locations. To this end, a fast and efficient vortex axis detection scheme is introduced and the algorithm for the vortex core border determination is explained. As the interaction between vortices makes the assignment of grid points to a certain vortex axis difficult, a helicity‐based vortex distinction approach in combination with a geometrical rotational sensor is developed. After describing the combined different techniques in detail, the vortex feature adaptation algorithm is applied to analytical and more realistic examples, which show that the described grid adaptation algorithm is able to enhance the grid cell resolution locally such that all significant vortical flow phenomena are resolved. Copyright © 2008 John Wiley & Sons, Ltd.

Surveillance Wireless Sensor Networks: Deployment Quality Analysis

Surveillance wireless sensor networks are deployed at perimeter or border locations to detect unauthorized intrusions. For deterministic deployment of sensors, the quality of deployment can be determined sufficiently by analysis in advance of deployment. However, when random deployment is required, determining the deployment quality becomes challenging. To assess the quality of sensor deployment, appropriate measures can be employed that reveal the weaknesses in the coverage of SWSNs with respect to the success ratio and time for detecting intruders. In this article, probabilistic sensor models are adopted, and the quality of deployment issue is surveyed and analyzed in terms of novel measures. Furthermore, since the presence of obstacles in the surveillance terrain has a negative impact on previously proposed deployment strategies and analysis techniques, we argue in favor of utilizing image segmentation algorithms by imitating the sensing area as a grayscale image referred to as the iso-sensing graph. Finally, the effect of sensor count on detection ratio and time to detect the target is analyzed through OMNeT++ simulation of an SWSN in a border surveillance scenario.

Education and migration in a border city

Major demographic processes (fertility, mortality and migration) are both causes and consequences of future and previous processes. Demographers in border locations have special methodological challenges and usually face more rapidly changing dynamics than other locations. Migration is a process most difficult to both measure and understand; unlike birth and death, it does not happen to everyone, but is selective. Age, education, health, wealth, occupation, gender and family composition all contribute to making a person more or less likely to move from one place to another or remain where they are, as are a host of other factors. This study attempts to sort out some of these factors, using primarily Census data from 1990 and 2000. We began with the local concern that El Paso's persistently low indices of education and income result from an outflow of the more educated segments of the community. However, our findings suggest that the relationship between migration and education is not linear. Moreover, other variables such a language, birthplace, gender and ethnicity appear to be as or more important in predicting whether a person will stay or leave than educational attainment. The characteristics of new arrivals also affect the composition of a population at the aggregate level. As the population of Hispanics disperse throughout the country, a process rapidly underway as evidenced by the 2000 Census, our findings may have implications for many other communities. A more complete understanding of the causes and consequences of migration will require a combination of both qualitative and quantitative analysis.

Discursive strategies for coping with sensitive topics of the Other

This paper explores border residents' strategies for coping with topics which they perceive as difficult or sensitive in their discourses about people living in such European border locations. Thus we are concerned with the way in which people negotiate accounts of implicit or explicit ethnic conflict, prejudice or negative stereotyping of ‘the Other’. We indicate two types of such strategies. First, the strategy of mitigation, in which informants attempt to soften or licence their stereotypical views. Second, we shall discuss a strategy in which mitigation is replaced by the practice of ‘oracular reasoning’ in our informants' constructions of the ethnic Other; this occurs in those instances when a basic premise is confronted with contradictory evidence, but the evidence is ignored or rejected. The data for our analysis come from 12 border communities in which informants talk about the Other from either across the border, or, in the case of multi-ethnic communities, from within the community itself. We focus upon constructions that purport to give a universal answer to questions of ‘what they are like’. Specifically, we explore those constructions where informants have to deal with conflictual voices (either explicit or implicit in the informants' discourse) which question their accounts or contradict the claims they make. Finally, we see the strategies for coping with conflictual accounts of the Other as indicative of the tension between the discursively postulated social/ethnic separation of the border communities and the constructed threat from the Other on the one hand, and, on the other hand, the new and changing public discourse of the Other and the politics underpinning it which goes counter to those more private discourses.

Response to Intruders and the Dear Enemy Phenomenon in Female Tree Lizards, Urosaurus ornatus, in Relation to Age and Reproductive Condition

Response to Intruders and the Dear Enemy Phenomenon in Female Tree Lizards, Urosaurus ornatus, in Relation to Age and Reproductive Condition

Asymptotic analysis of growing crack stress/deformation fields in porous ductile metals and implications for stable crack growth

Asymptotic stress and deformation fields near a quasi-statically growing plane strain tensile crack tip in porous elastic-ideally plastic material, characterized by the Gurson-Tvergaard yield condition and associated flow rule, are derived for small uniform porosity levels throughout the range 0 to 4.54 percent. The solution configuration resembles that for crack growth in fully dense, elastically compressible, elastic-ideally plastic Huber-Mises material for this porosity range, except that the angular extents and border locations of near-tip solution sectors vary with porosity level, as do the stress and deformation fields within sectors. Increasing porosity is found to result in a dramatic reduction in maximum hydrostatic stress level, greater than that for a stationary crack; it also causes a significant angular redistribution of stresses, particularly for a range of angles ahead of the crack and adjacent to the crack flank. The near-tip deformation fields derived are employed to generalize a previously-developed, successful ductile crack growth criterion. Our model predicts that for materials having the same initial slopes of their crack growth resistance curves, but different levels of uniform porosity, higher porosity results in a substantially greater propensity for stable crack growth.

Feature extraction in two-dimensional short-axis echocardiographic images

An automatic method for identification of the center point of the left ventricle of the myocardium during systole in two-dimensional short-axis echocardiographic images is described. This method, based on the use of large matched filters, identifies a single fixed center point during systole by locating three key features: the epicardial border along the posterior wall, the epicardial border along the anterior wall, and the endocardial border along the anterior wall. Thus it provides a first step toward the long-term goal of automatic recognition of all the endocardial and epicardial borders. An index (or normalized output value) associated with the filter used to approximate the epicardial boundary along the posterior wall provides an indication of the quality of the image and a reliability measurement of the estimate. When this method was tested on 207 image sequences, 18 images were identified by this index (applied to the end diastolic frame) as unsuitable for processing. In the remaining 189 image sequences, 173 of the automatically defined center points were judged to be in good agreement with estimates made on the end diastolic frame by an independent expert observer. Thus only 16 automatically defined centers were judged to be in poor agreement. Comparisons of the computer and expert-observer estimates were also made for the three key border locations.