Some properties of the dissipative model of strain-gradient plasticity

A theoretical and computational investigation is carried out of a dissipative model of rate-independent strain-gradient plasticity and its regularization. It is shown that the flow relation, when expressed in terms of the Cauchy stress, is necessarily global. The most convenient approach to formulating the flow relation is through the use of a dissipation function. It is shown, however, that the task of obtaining the dual version, in the form of a normality relation, is a complex one. A numerical investigation casts further light on the response using the dissipative theory in situations of non-proportional loading. The elastic gap, a feature reported in recent investigations, is observed in situations in which passivation has been imposed. It is shown computationally that the gap may be regarded as an efficient path between a load-deformation response corresponding to micro-free boundary conditions, and that corresponding to micro-hard boundary conditions, in which plastic strains are set equal to zero.Comment: 26 pages, 10 figure

ON THE DETERMINANTS OF LEVERAGED BUYOUT ACTIVITY: A COMPARISON BETWEEN DEVELOPED AND DEVELOPING ECONOMIES

I study Leveraged buyouts (LBOs) internationally over the period 1980-2012. Returns on LBOs are on average higher for developed markets. However, returns of LBOs during high economic growth periods are high for developing nations relative to developed economies. On the other hand returns in developing nations are lower when compared to the returns in developed nations in periods of negative economic growth. During periods of negative economic growth, the returns in developing nations do not compensate for the high risk associated with them. Developing countries are more unstable relative to developed countries during conditions of boom as well as collapse. Exit times for LBO transactions in developing economies are therefore shorter relative to developed economies in periods of high economic growth rate. This is because PE investment firms would like to exit soon and lock in their profits. During periods of negative economic growth rate, the LBOs in developing nations exit sooner. When things go badly in the developing economies, they are magnified multiple times. Hence the PE firms would like to avoid further losses and hence exit sooner. In periods of low or medium economic growth, LBOs in developing economies take longer times to exit. Reputed firms and small firms have higher returns and exit sooner. Club deals have higher returns and exit sooner when compared with single PE firm deals, until the year there was higher government on the motive of club deals. After 2006 there was higher government scrutiny which make club deals take longer time to exit. Club deals in developing economies are on average not profitable and exit sooner

Methods to estimate link level travel based on spatial effects

Annual Average Daily Traffic (AADT) is used in several planning, roadway design, operational and safety analyses by transportation planners and engineers. Existing methods are very complex and do not adequately address the modeling needs. Errors and inaccuracies in a traditional four-step method get carried to later steps often resulting in incorrect estimates of travel demand. The primary focus of this research is to develop a systematic and simplified methodology to estimate link level travel on roadways. The proposed methodology involves scientific principles and statistical techniques, but bypasses the tedious four-step method. Two spatial methods, first one based on “spatial proximity” and second one based on “spatial weighting”, are proposed to estimate link level travel. While the former method investigates to identify ideal “proximal” distance to capture spatial data, the later method involves application of “spatial weights” that decrease with an increase in distance to integrate spatial data from multiple buffer bandwidths. Generalized Estimating Equations (GEE) models are developed for both the methods using Poisson and Negative Binomial distributions with and without network characteristics to facilitate transportation planning and analysis. Validation of the developed models is carried out using Chi-Square Statistic test. The goodness of fit statistics indicates that Negative Binomial models performed better than Poisson models. Models with network characteristics performed better than models without network characteristics. Model validation results indicate that link level travel can be accurately estimated using both the spatial methods

Universally composable zero-knowledge protocol using trusted platform modules

Cryptographic protocols that are established as secure in the Universally Composable (UC) model of security provide strong security assurances even when run in complex environments. Unfortunately, in order to achieve such strong security properties, UC protocols are often impractical, and most non-trivial two-party protocols cannot be secure in the UC model without some sort of external capability (or "setup assumption") being introduced. Recent work by Hofheinz et al provided an important breakthrough in designing realistic universally composable two party protocols, in which they use trusted, tamper proof hardware as a special type of helping functionality which they call a catalyst. Hofheinz et al. use government issued signature cards as a catalyst to design universally composable protocols for zero-knowledge proofs and commitments, but did not give a complete security proof for either protocol. In this thesis, we consider another form of security hardware, Trusted Platform Modules (TPMs), which are more widespread than signature cards and are currently shipped as a part of almost every business laptop or desktop. Trusted Module Platforms are tamper evident devices which support cryptographic functionalities including digital signatures, but have a different key management model from signature cards. In this thesis we consider TPMs as catalysts and describe a universally composable zero knowledge protocol using Trusted Platform Modules. We also present a complete security proof for both the Hofheinz's universally composable zero knowledge protocol from signature cards and our universally composable zero knowledge protocol using TPMs as a catalyst

Nitrated fatty acids reverse cigarette smoke-induced alveolar macrophage activation and inhibit protease activity via electrophilic S-alkylation

Nitrated fatty acids (NFAs), endogenous products of nonenzymatic reactions of NO-derived reactive nitrogen species with unsaturated fatty acids, exhibit substantial anti-inflammatory activities. They are both reversible electrophiles and peroxisome proliferator-activated receptor γ (PPARγ) agonists, but the physiological implications of their electrophilic activity are poorly understood. We tested their effects on inflammatory and emphysema-related biomarkers in alveolar macrophages (AMs) of smoke-exposed mice. NFA (10-nitro-oleic acid or 12-nitrolinoleic acid) treatment downregulated expression and activity of the inflammatory transcription factor NF-κB while upregulating those of PPARγ. It also downregulated production of inflammatory cytokines and chemokines and of the protease cathepsin S (Cat S), a key mediator of emphysematous septal destruction. Cat S downregulation was accompanied by decreased AM elastolytic activity, a major mechanism of septal destruction. NFAs downregulated both Cat S expression and activity in AMs of wild-type mice, but only inhibited its activity in AMs of PPARγ knockout mice, pointing to a PPARγ-independent mechanism of enzyme inhibition. We hypothesized that this mechanism was electrophilic S-alkylation of target Cat S cysteines, and found that NFAs bind directly to Cat S following treatment of intact AMs and, as suggested by in silico modeling and calculation of relevant parameters, elicit S-alkylation of Cys25 when incubated with purified Cat S. These results demonstrate that NFAs' electrophilic activity, in addition to their role as PPARγ agonists, underlies their protective effects in chronic obstructive pulmonary disease (COPD) and support their therapeutic potential in this disease

Ladson-Billings' culturally relevant pedagogy is not measuring up - and that's exactly as it should be! : a philosophical reading of the problem of static ways of thinking about culture in our epoch of calculative, scientific thinking

Since 1989 one of the undisputed leaders in the field of culturally meaningful pedagogy, Gloria Ladson-Billings, has persistently reminded educators about one core idea - any practice that is committed to meaningful engagement with cultural identity should conceive of culture as being fluid. Yet we are recalcitrant in changing how we think about culture. We continue to practice under the assumption that culture can be easily categorized, fully known, preserved, and then seamlessly transmitted from teacher to student, or vice versa. In 2014, Ladson-Billings expressed her dissatisfaction with our static conception and superficial notions which results in the fluidity and variety within cultural groups being lost. If it is indeed our conception of culture that renders it stagnant, should we not then give this problem of a fixed cultural conception of culture a philosophical reading that explores how different modes of thinking can render culture static? To explore different modes of thinking, I converse with four philosophers: Martin Heidegger, a German, who thinks away from the classical western, calculative ways of his time offers us meditative thinking. Calvin Warren, an Afro-pessimist and Marimba Ani, an Afro-centrist open a space for thinking informed by spirit. Carl Mika, a Maori scholar invites us to think speculatively. These scholars all offer us different ways of thinking about the paradox of the human condition - our pre-ontological propensity for openness and fluidity, and our accompanying ontological anxiety that forecloses on this openness. Through close textual analysis, we explore what’s at stake for Culturally Relevant Pedagogy in the face of this paradox

Model for analyzing course description using LDA topic modeling

This study demonstrates a way to generate a Topic model using LDA (Latent Dirichlet Allocation) topic modeling for the courses of multiple universities in the USA, which is relatively significant. This model will specifically be able to differentiate the course structure between various universities, such as the University of North Carolina at Wilmington, the University of North Texas, the University of South Carolina, and the University of Western Carolina. This model will help find the related courses of a selected department of study, or so they thought. The LDA (Latent Dirichlet Allocation) topic model is used to infer topics from the content in the university course description. Further, this study showed how to generate a Topic model using LDA (Latent Dirichlet Allocation) topic modeling for the courses of multiple universities in the USA. This study will: Explain how to Infer topics from the corpora consisting of various universities’ text of course details; Helps to find out the related courses of a selected department of study in a big way; Group the topics into different communities by calculating the Modularity with the help of the Louvain method; Analyze how the courses are related to the topics, for the most part subtly inferred for each University; For a selected Department of study, see what all courses belongs to this department with the help of topics generated. This study helps us to identify the courses which have a relation with a selected department of study. The graph representations mainly included in this paper will generally explain our Approach

Childhood-onset Leber hereditary optic neuropathy

BACKGROUND: The onset of Leber hereditary optic neuropathy (LHON) is relatively rare in childhood. This study describes the clinical and molecular genetic features observed in this specific LHON subgroup. METHODS: Our retrospective study consisted of a UK paediatric LHON cohort of 27 patients and 69 additional cases identified from a systematic review of the literature. Patients were included if visual loss occurred at the age of 12 years or younger with a confirmed pathogenic mitochondrial DNA mutation: m.3460G>A, m.11778G>A or m.14484T>C. RESULTS: In the UK paediatric LHON cohort, three patterns of visual loss and progression were observed: (1) classical acute (17/27, 63%); (2) slowly progressive (4/27, 15%); and (3) insidious or subclinical (6/27, 22%). Diagnostic delays of 3-15 years occurred in children with an insidious mode of onset. Spontaneous visual recovery was more common in patients carrying the m.3460G>A and m.14484T>C mutations compared with the m.11778G>A mutation. Based a meta-analysis of 67 patients with available visual acuity data, 26 (39%) patients achieved a final best-corrected visual acuity (BCVA) ≥0.5 Snellen decimal in at least one eye, whereas 13 (19%) patients had a final BCVA <0.05 in their better seeing eye. CONCLUSIONS: Although childhood-onset LHON carries a relatively better visual prognosis, approximately 1 in 5 patients will remain within the visual acuity criteria for legal blindness in the UK. The clinical presentation can be insidious and LHON should be considered in the differential diagnosis when faced with a child with unexplained subnormal vision and optic disc pallor

Epidemiology and patterns of care for invasive breast carcinoma at a community hospital in Southern India

<p>Abstract</p> <p>Background</p> <p>Breast cancer incidence in India is on rise. We report epidemiological, clinical and survival patterns of breast cancer patients from community perspective.</p> <p>Methods</p> <p>All breast cancer patients treated at this hospital from July 2000 to July 2005 were included. All had cytological or histological confirmation of breast cancer. TNM guidelines for staging and Immunohistochemistry to assess the receptor status were used. Either lumpectomy with axillary lymph node dissection or Modified radical mastectomy (MRM) was done for operable breast cancer, followed by 6 cycles of adjuvant chemotherapy with FAC or CMF regimens to patients with pT >1 cm or lymph node positive or estrogen receptor negative and radiotherapy to patients after breast conservation surgery, pT size > 5 cm, 4 or more positive nodes and stage IIIB disease. Patients with positive Estrogen receptor or Progesterone receptor were advised Tamoxifene 20 mg per day for 3 years. Descriptive analysis was performed. Independent T test and Chi-square test were used. Overall survival time was computed by Kaplan – Meier method.</p> <p>Results</p> <p>Of 1488 cancer patients, 122 (8.2%) had breast cancer. Of 122 patients, 96.7% had invasive breast carcinoma and 3.3% had sarcoma. 94% came from the rural and semi urban areas. Premenopausal women were 27%. The median age was 50 years. Stage I-6.8%, II-45.8%, III-22%, IV-6.8%, Bilateral breast cancer – 2.5%. The mean pT size was 3.9 cm. ER and PR were positive in 31.6% and 28.1% respectively. MRM was done in 93.8%, while 6.3% patients underwent breast conservation surgery. The mean of the lymph nodes dissected were 3. CMF and FAC regimens were used in 48.8% and 51.2% of patients respectively. FAC group were younger than the CMF group (43.6 yr vs. 54 yrs, P = 0.000). Toxicities were more in FAC than CMF group, alopecia (100% vs. 26.2%), grade2 or more emesis (31.8% vs. 9.2%), grade2 or more fatigue (40.9% vs.19%), anemia (43.1% vs. 16.6%). Median Survival for the cohort was 50.8 months. ER positive patients had better median survival (P = 0.05).</p> <p>Conclusion</p> <p>MRM was the most frequent surgical option. CMF and FAC showed equivalent survival. FAC chemotherapy was more toxic than CMF. ER positive tumors have superior survival. Overall 3 year survival was 70 percent</p