2,127 research outputs found
Boundary Effects in the One Dimensional Coulomb Gas
We use the functional integral technique of Edwards and Lenard to solve the
statistical mechanics of a one dimensional Coulomb gas with boundary
interactions leading to surface charging. The theory examined is a one
dimensional model for a soap film. Finite size effects and the phenomenon of
charge regulation are studied. We also discuss the pressure of disjunction for
such a film. Even in the absence of boundary potentials we find that the
presence of a surface affects the physics in finite systems. In general we find
that in the presence of a boundary potential the long distance disjoining
pressure is positive but may become negative at closer interplane separations.
This is in accordance with the attractive forces seen at close separations in
colloidal and soap film experiments and with three dimensional calculations
beyond mean field. Finally our exact results are compared with the predictions
of the corresponding Poisson-Boltzmann theory which is often used in the
context of colloidal and thin liquid film systems.Comment: 28 pages, LATEX2e, 11 figures, uses styles[12pt] resubmission because
of minor corrections to tex
Social Entrepreneurship: The Ideal Business for Humanity and the Economy
This essay argues that social entrepreneurship is the most efficient means to generate lasting social change and permanently reduce poverty. Using the support of scholarly research, interviews with experts in the field, and my own qualitative observations, I conclude that traditional aid models that are economically dependent on outside funding, as well as those that simply provide monetary and product contributions in order to sustain the poor or marginalized communities they serve are inherently structured in a way that prevents them from resolving social ills. Despite the influx of aid organizations over past decades, chronic poverty and other serious social problems persist, and have not been significantly impacted on a global scale. Traditional aid models merely treat the fundamental issues that perpetuate global poverty. Ironically, these methods of aid actually sustain the inherent problems. Social entrepreneurship is one of the only models that has successfully initiated wide scale social development through promoting the economic independence and self-sustainability of the communities influenced by their initiatives. It has proven to incorporate the necessary tactics that, if implemented internationally and on a wide scale, has the potential to permanently and significantly impact global poverty
The Y2K Problem: Proposed Statute to Guide Triers of Fact in Determinations of Negligence
Following the coming new year, the Y2K Problem will create problems worldwide. While the exact extent of its harm is open to debate, there is no disagreement over its inevitability. In fact, some computer-related companies (including the makers of Norton Anti-Virus and Quicken for Windows have already been sued for damages arising from allegedly non-Y2K-compliant products. While various actors at all levels of business and government will be subject to legal liability for such malfunctions, this article will examine the legal liability of software producers and engineers under current remedial theories. Software manufacturers are a logical choice for this examination because they will likely be ultimately liable for most Y2K errors. For instance, if an individual sues his bank for miscalculation of interest arising from Y2K errors, the bank will, in turn, bring an action against the maker of the software responsible for such calculations. This scenario will repeat itself in many contexts
Attitudes of surgeons to the use of postoperative markers of the systemic inflammatory response following elective surgery
Background:
Cancer is responsible for 7.6 million deaths worldwide and surgery is the primary modality of a curative outcome. Postoperative care is of considerable importance and it is against this backdrop that a questionnaire based study assessing the attitudes of surgeons to monitoring postoperative systemic inflammation was carried out.
Method:
A Web based survey including 10 questions on the “attitudes of surgeons to the use of postoperative markers of the systemic inflammatory response following elective surgery” was distributed via email. Two cohorts were approached to participate in the survey. Cohort 1 consisted of 1092 surgeons on the “Association of Coloproctology of Great Britain and Ireland (ACPGBI)” membership list. Cohort 2 consisted of 270 surgeons who had published in this field in the past as identified by two recent reviews. A reminder email was sent out 21 days after the initial email in both cases and the survey was closed after 42 days in both cases.
Result:
In total 29 surgeons (2.7%) from cohort 1 and 40 surgeons (14.8%) from cohort 2 responded to the survey. The majority of responders were from Europe (77%), were colorectal specialists (64%) and were consultants (84%) and worked in teaching hospitals (54%) and used minimally invasive techniques (87%). The majority of responders measured CRP routinely in the post-operative period (85%) and used CRP to guide their decision making (91%) and believed that CRP monitoring should be incorporated into postoperative guidelines (81%).
Conclusion:
Although there was a limited response the majority of surgeons surveyed measure the systemic inflammatory response following elective surgery and use CRP measurements together with clinical findings to guide postoperative care. The present results provide a baseline against which future surveys can be compared
Path integrals for stiff polymers applied to membrane physics
Path integrals similar to those describing stiff polymers arise in the
Helfrich model for membranes. We show how these types of path integrals can be
evaluated and apply our results to study the thermodynamics of a minority
stripe phase in a bulk membrane. The fluctuation induced contribution to the
line tension between the stripe and the bulk phase is computed, as well as the
effective interaction between the two phases in the tensionless case where the
two phases have differing bending rigidities.Comment: 11 pages RevTex, 4 figure
Some observations on the renormalization of membrane rigidity by long-range interactions
We consider the renormalization of the bending and Gaussian rigidity of model
membranes induced by long-range interactions between the components making up
the membrane. In particular we analyze the effect of a finite membrane
thickness on the renormalization of the bending and Gaussian rigidity by
long-range interactions. Particular attention is paid to the case where the
interactions are of a van der Waals type.Comment: 11 pages RexTex, no figure
The role of dietary polyphenols in the moderation of the inflammatory response in early stage colorectal cancer
Current focus in colorectal cancer management is on reducing overall mortality by increasing the number of early stage cancers diagnosed and treated with curative intent. Despite the success of screening programmes in down-staging colorectal cancer, interval cancer rates are substantial and other strategies are desirable. Sporadic colorectal cancer is largely associated with lifestyle factors including diet. Polyphenols are phytochemicals ingested as part of a normal diet which are abundant in plant foods including fruits/berries and vegetables. These may exert their anti-carcinogenic effects via the modulation of inflammatory pathways. Key signal transduction pathways are fundamental to the association of inflammation and disease progression including those mediated by NF-ÎşB and STAT, PI3K and COX. Our aim was to examine the evidence for the effect of dietary polyphenols intake on tumour and host inflammatory responses to determine if polyphenols may be effective as part of a dietary intervention. There is good epidemiological evidence of a reduction in colorectal cancer risk from case-control and cohort studies assessing polyphenol intake. It would be premature to suggest a major public health intervention to promote their consumption however, dietary change is safe and feasible, emphasising the need for further investigation of polyphenols and colorectal cancer risk
Comparison of the prognostic value of measures of the tumor inflammatory cell infiltrate and tumor-associated stroma in patients with primary operable colorectal cancer
The aim of the present study was to compare the clinical utility of two measures of the
inflammatory cell infiltrate - a H&E-based assessment of the generalised inflammatory cell
infiltrate (the Klintrup-Mäkinen (KM) grade), and an immunohistochemistry-based
assessment of combined CD3+ and CD8+ T-cell density (the “Immunoscore”), in conjunction
with assessment of the tumor stroma percentage (TSP) in patients undergoing resection of
stage I-III colorectal cancer (CRC). 246 patients were identified from a prospectively
maintained database of CRC resections in a single surgical unit. Assessment of KM grade
and TSP was performed using full H&E sections. CD3+ and CD8+ T-cell density was
assessed on full sections and the Immunoscore calculated. KM grade and Immunoscore were
strongly associated (P<0.001). KM grade stratified cancer-specific survival (CSS) from 88%
to 66% (P=0.002) and Immunoscore from 93% to 61% (P<0.001). Immunoscore further
stratified survival of patients independent of KM grade from 94% (high KM, Im4) to 60%
(low KM, Im0/1). Furthermore, TSP stratified survival of patients with a weak inflammatory
cell infiltrate (low KM: from 75% to 47%; Im0/1: from 71% to 38%, both P<0.001) but not
those with a strong inflammatory infiltrate. On multivariate analysis, only Immunoscore (HR
0.44, P<0.001) and TSP (HR 2.04, P<0.001) were independently associated with CSS. These
results suggest that the prognostic value of an immunohistochemistry-based assessment of the
inflammatory cell infiltrate is superior to H&E-based assessment in patients undergoing
resection of stage I-III CRC. Furthermore, assessment of the tumor-associated stroma, using
TSP, further improves prediction of outcome
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