790,185 research outputs found
Excision margins in breast conserving surgery
The ideal excision margin in breast
conserving surgery is still a matter of debate. The aim is to
see if there is any correlation between increasing
excision margin distance and local recurrence rate.
Patients who had breast
conserving surgery at Mater Dei Hospital in 2009 had
their notes reviewed retrospectively. Patient
demograpichs, including the excision margins were
recorded. Local recurrences within a 3 year follow up
period were noted. Chi square was used to compare
categorical data and a p value of less than 0.05 was
considered statistically significant.
91 patients were recruited into the study. 74
patients (81.5%) had negative margins (>1mm), 10
patients (11%) had close margins (<1mm) while 7
patients (7.5%) had positive margins. 5 patients (5.5%)
had local recurrence. The highest recurrence rate (14%)
was in patients with positive margins, and no statistical
signficant difference in recurrence rates was noted with
wider excision margins.
As long as the margins are negative,
increasing excision margins will not result in a better
local recurrence rate.peer-reviewe
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Success rates of re-excision after positive margins for invasive lobular carcinoma of the breast.
Rates of positive margins after surgical resection of invasive lobular carcinoma (ILC) are high (ranging from 18 to 60%), yet the efficacy of re-excision lumpReceptor subtypeectomy for clearing positive margins is unknown. Concerns about the diffuse nature of ILC may drive increased rates of completion mastectomy to treat positive margins, thus lowering breast conservation rates. We therefore determined the success rate of re-excision lumpectomy in women with ILC and positive margins after surgical resection. We identified 314 cases of stage I-III ILC treated with breast conserving surgery (BCS) at the University of California, San Francisco. Surgical procedures, pathology reports, and outcomes were analyzed using univariate and multivariate statistics and Cox-proportional hazards models. We evaluated outcomes before and after the year 2014, when new margin management consensus guidelines were published. Positive initial margins occurred in 118 (37.6%) cases. Of these, 62 (52.5%) underwent re-excision lumpectomy, which cleared the margin in 74.2%. On multivariate analysis, node negativity was significantly associated with successful re-excision (odds ratio [OR] 3.99, 95% CI 1.15-13.81, p = 0.029). After 2014, we saw fewer initial positive margins (42.7% versus 25.5%, p = 0.009), second surgeries (54.6% versus 20.2%, p < 0.001), and completion mastectomies (27.7% versus 4.5%, p < 0.001). In this large cohort of women with ILC, re-excision lumpectomy was highly successful at clearing positive margins. Additionally, positive margins and completion mastectomy rates significantly decreased over time. These findings highlight improvements in management of ILC, and suggest that completion mastectomy may not be required for those with positive margins after initial BCS
The determinants of bank margins revisited: A note on the effects of diversification
Most of the theoretical and empirical literature on bank margins has dealt solely with interest margins. Applying the seminal Ho-Saunders model (JFQA, 1981) to a multi-output framework, we show that the relationship between bank margins and market power (controlling for risk) varies significantly across bank specializations. Using a set of both accounting margins and New Empirical Industrial Organization (NEIO) margins, we find that market power rises significantly with output diversification towards non-traditional activities. These results contribute to explain the paradoxical coexistence of decreasing interest margins and higher market power found in previous studies.bank margins, specialization, market structure.
The Determinants of the Interest Rate Margins of Czech Banks
The author examines the determinants of the interest rate margins of Czech banks by employing a bank-level dataset at quarterly frequency in 2000–2006. His main results are as follows. He finds that more efficient banks exhibit lower margins and there is no evidence that banks with lower margins compensate themselves with higher fees. Price stability contributes to lower margins. Higher capital adequacy is associated with lower margins, contributing to banking stability. Overall, the results indicate that the determinants of the interest rate margins of Czech banks are largely similar to those reported in other studies for developed countries.commercial banks, interest rate margins, bank efficiency
Meaning in the margins: postcolonial feminist methodologies in practical theology
This paper troubles research approaches in practical theology by exploring how attention to lived experiences of marginalization in postcolonial feminist theologies shapes theological methodologies. Drawing on the work of Walter Mignolo and Marcella Althaus-Reid, the margins are explored as epistemological and material sites that shape theological knowledge production. The complex intersections of experiences and identities of lives on the margins require a resistance to taxonomic or technical theological methodologies. As discussed by Mayra Rivera and Ada María Isasi-Díaz, the margins are not sites of deprivation, but of critical praxis, so theological methodology must be attentive to everyday experiences of the margins. The paper highlights where postcolonial feminist theologies add to practical theology about poetics by attending to making meaning. The paper concludes by reflecting on academic engagement with postcolonial feminist theology and the lived experiences of the margins
How Bees Respond Differently to Field Margins of Shrubby and Herbaceous Plants in Intensive Agricultural Crops of the Mediterranean Area
(1) Intensive agriculture has a high impact on pollinating insects, and conservation strategies targeting agricultural landscapes may greatly contribute to their maintenance. The aim of this work was to quantify the effect that the vegetation of crop margins, with either herbaceous or shrubby plants, had on the abundance and diversity of bees in comparison to non-restored margins. (2) The work was carried out in an area of intensive agriculture in southern Spain. Bees were monitored visually and using pan traps, and floral resources were quantified in crop margins for two years. (3) An increase in the abundance and diversity of wild bees in restored margins was registered, compared to non-restored margins. Significant differences in the structure of bee communities were found between shrubby and herbaceous margins. Apis mellifera and mining bees were found to be more polylectic than wild Apidae and Megachilidae. The abundance of A. mellifera and mining bees was correlated to the total floral resources, in particular, to those offered by the Boraginaceae and Brassicaceae; wild Apidae and Megachilidae were associated with the Lamiaceae. (4) This work emphasises the importance of floral diversity and shrubby plants for the maintenance of rich bee communities in Mediterranean agricultural landscapes
Ring oscillator clocks and margins
How much margin do we have to add to the delay lines of a bundled-data circuit? This paper is an attempt to give a methodical answer to this question, taking into account all sources of variability and the existing EDA machinery for timing analysis and sign-off. The paper is based on the study of the margins of a ring oscillator that substitutes a PLL as clock generator. A timing model is proposed that shows that a 12% margin for delay lines can be sufficient to cover variability in a 65nm technology. In a typical scenario, performance and energy improvements between 15% and 35% can be obtained by using a ring oscillator instead of a PLL. The paper concludes that a synchronous circuit with a ring oscillator clock shows similar benefits in performance and energy as those of bundled-data asynchronous circuits.Peer ReviewedPostprint (author's final draft
Botanical rejuvenation of field margins and benefits for invertebrate fauna on a drystock farm in County Longford
peer-reviewedThis study investigates methods to rejuvenate the fl ora of previously degraded fi eld margins on a pastoral farm in County Longford. We also assess the effects of individual treatments on the abundance
of various orders of invertebrates recorded within the experimental plots. Field margin treatments were 1.5m-wide unfenced control margins, 1.5m-wide fenced margins or 3.5m-wide fenced margins. Nutrient inputs were excluded from all of the experimental plots. The botanical composition of the
plots was examined on four occasions between 2002 and 2004 using permanent, nested quadrats. Emergence traps were used to measure invertebrate abundance within treatment plots and the main sward. Results indicated that 1) exclusion of nutrient inputs had a positive effect on plant species
richness within the fi eld margins; 2) plant species richness decreased with increased distance from the hedgerow; 3) herb species richness was greatest in the 1.5m closest to the hedgerow; 4) greater abundance of invertebrates occurred within the 3.5m-wide margins; 5) successful control of Pteridium
aquilinum was achieved through spot treatment with the selective herbicide ‘Asulox’; and 6) a combination
of management techniques such as cutting and grazing is likely to enhance plant species richness and facilitate the structural diversity of vegetation that is necessary for many invertebrate taxa.Teagasc Walsh Fellowship Programm
Edward Said and the Margins
Edward Said was the quintessential intellectual of the last quarter of the twentieth century. Commonly celebrated as the founding figure of postcolonialism, his critical oeuvre spans varied terrain. The very strength of his critique lies in these diverse tributaries of thought. Crossing borders and boundaries incessantly, Said’s intellectual project celebrates the culture of resistance while opposing doctrinaire rhetoric. The paper tries to journey along the multifarious “margins” of discourses that crop up in Said. “In-between” spaces have to be investigated for their radical potential, while daring to “transgress” has its own dangers. Said unmasks the unholy nexus between knowledge and power in the mapping of the “Orient” that abetted the colonial enterprise. His contrapuntal readings of literary texts reveal the ubiquitous presence of imperial empire. Consequently, voices from the margins spur counter narratives and “writing back” in the postcolonial condition. Intellectuals in exile tend to be “marginal” and this location helps in looking at the two or even three sides of an issue. Questions of identity, selfhood, nationality, politics, memory, history, representation, geography, homeland, anxieties of influence are dealt with in the paper. The intertwining of the personal and the political occurs in Said. “Memory” is the only hope for resuscitating a “lost world” and battling the accompanying sense of “loss” and “despair” infused in both individuals and communities alike. The paper tries to address how “border crossing” and the “coalescing of margins” create an interdisciplinary breadth in Said, which resist categorization. The “centre/margin” binary is problematized by acknowledging the presence of “many voices,” “polyphony” being a favourite concept of Said. Music gave to him metaphors for human emancipation, while “transgression” was vital. His acknowledgement and assimilation of fellow critics is also mentioned. Beyond enunciating insider-outsider distinctions, Said tried to cultivate knowledge as a bridge between different interests and locations
Margins of discrete Bayesian networks
Bayesian network models with latent variables are widely used in statistics
and machine learning. In this paper we provide a complete algebraic
characterization of Bayesian network models with latent variables when the
observed variables are discrete and no assumption is made about the state-space
of the latent variables. We show that it is algebraically equivalent to the
so-called nested Markov model, meaning that the two are the same up to
inequality constraints on the joint probabilities. In particular these two
models have the same dimension. The nested Markov model is therefore the best
possible description of the latent variable model that avoids consideration of
inequalities, which are extremely complicated in general. A consequence of this
is that the constraint finding algorithm of Tian and Pearl (UAI 2002,
pp519-527) is complete for finding equality constraints.
Latent variable models suffer from difficulties of unidentifiable parameters
and non-regular asymptotics; in contrast the nested Markov model is fully
identifiable, represents a curved exponential family of known dimension, and
can easily be fitted using an explicit parameterization.Comment: 41 page
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