2,499 research outputs found

    Laplacian Distribution and Domination

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    Let mG(I)m_G(I) denote the number of Laplacian eigenvalues of a graph GG in an interval II, and let γ(G)\gamma(G) denote its domination number. We extend the recent result mG[0,1)γ(G)m_G[0,1) \leq \gamma(G), and show that isolate-free graphs also satisfy γ(G)mG[2,n]\gamma(G) \leq m_G[2,n]. In pursuit of better understanding Laplacian eigenvalue distribution, we find applications for these inequalities. We relate these spectral parameters with the approximability of γ(G)\gamma(G), showing that γ(G)mG[0,1)∉O(logn)\frac{\gamma(G)}{m_G[0,1)} \not\in O(\log n). However, γ(G)mG[2,n](c+1)γ(G)\gamma(G) \leq m_G[2, n] \leq (c + 1) \gamma(G) for cc-cyclic graphs, c1c \geq 1. For trees TT, γ(T)mT[2,n]2γ(G)\gamma(T) \leq m_T[2, n] \leq 2 \gamma(G)

    Researching protest on Facebook: developing an ethical stance for the study of Northern Irish flag protest pages

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    This paper adds to the emergent literature on Internet research ethics by exploring the ethical implications of researching the use of Facebook to organize the union flag protests in Northern Ireland in January 2013. These protests were viewed as a ‘lightning rod’ for loyalist dissatisfaction with the peace process, as well as a manifestation of their increasing alienation from their unionist political representatives. The covert observation of the Loyalist Peaceful Protest Updater (LPPU) page in January 2013 found some evidence to support the suggestion that social media had become a ‘sectarian battleground’ during the flag protests. This created an ethical dilemma in terms of what level of anonymity should be afforded to those who posted such content on the page. While there was no requirement to ‘please’ unaware participants, the researcher was wary of inadvertently contributing to the online shaming of loyalists by groups such as Loyalists Against Democracy. Therefore, it was decided to only use direct quotes from public figures, such as the leaders of the flag protest movement, who would presumably have no expectation that their comments would remain private. The narratives of the ‘rank and file’ protesters were conveyed through the use of direct quotes that could not be traced back to their authors and the paraphrasing of their comments. In light of the limitations of alternative strategies such as fabrication and word clouds, this was the most appropriate way to illustrate the themes from the LPPU without distorting the voices of these users

    Cultures on the Screens: Family, Identity, Gender, and Language in Television Series

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    Even though the study of television fiction emerged as a relevant field of study in the 1970s, it is especially in the last three decades that attention has increasingly focused on TV series as a sophisticated form of expression and a fertile ground for research into the cultural dynamics that govern the representation of cultural identity, class, race, ethnicity, gender, and the use of language. The present collection originates from a research project, financed by the Department of Humanities of the University of Trieste, whose findings were first shared and debated with scholars from other Italian academic institutions, as well as students and the general public, in the course of a twoday conference held at the “Stazione Rogers” in Trieste, on 15-16 October, 2021. It presents, in amply revised and expanded form, papers which were first presented in that venue and which are representative of a variety of approaches to the study of TV series. The book discusses such acclaimed TV series as The Americans, The Affair, Modern Family, Dragnet, and When They See Us

    Elevated cystatin-C concentration is associated with progression to prediabetes: the Western New York Study

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    OBJECTIVE – We conducted a nested case-control investigation to examine if elevated baseline concentrations of cystatin-C predicted progression from normoglycaemia to prediabetes over 6 years of follow-up from the Western New York Health Study. RESEARCH DESIGN AND METHODS – 1,455 participants from the Western New York Health Study, free of type 2 diabetes and known cardiovascular disease at baseline (1996-2001), were reexamined in 2002-2004. An incident case of prediabetes was defined as one with fasting glucose below 100 mg/dl at the baseline examination and ≥ 100 mg/dl and ≤ 125 mg/dl at the follow-up examination. All cases (n=91) were matched 1:3 to control participants based upon sex, race/ethnicity and year of study enrollment. All controls had fasting glucose levels < 100 mg/dl at both baseline and follow-up examinations. Cystatin-C concentrations and the urinary albumin to creatinine ratio were measured from frozen (-196 Cº) baseline blood and urine samples. Serum creatinine concentrations were available from the baseline examination. RESULTS –Multivariate conditional logistic regression analyses adjusted for age, baseline glucose level, HOMA-IR, body mass index, hypertension, eGFR, cigarette smoking, and alcohol use revealed a significantly increased risk of progression to prediabetes among those with elevated baseline concentrations of cystatin-C (Odds Ratio, 95% CI: 3.04, 1.34, 6.89) (upper quintile vs. the remainder). Results of secondary analyses that considered hs-CRP, IL-6, E-selectin, or sICAM did not alter these results. CONCLUSIONS - These results suggest that early renal impairment indexed with cystatin-C imparted a three-fold excess risk of progression to prediabetes in this study population. Recent evidence from randomized clinical trials (1,2) among people with prediabetes have provided convincing evidence that early intervention can significantly delay or prevent the progression to type 2 diabetes. The identification of those with prediabetes is assuming greater importance (3) especially in light of the fact that approximately 35 million adults aged 40-74 years old in the United States have prediabetes defined as impaired fasting glucose (4). Microalbuminuria occurs frequently in nondiabetic subjects and places them at increased risk for cardiovascular disease (5-7). The mechanisms behind this observation are poorly understood, however. Albuminuria may reflect underlying vascular damage (8), hypertension (9, 10) endothelial dysfunction (11, 12) and/or low-grade inflammation (13). A large percentage of type 2 individuals pass through a period of prediabetes (14) and may experience early renal dysfunction e.g., a glomerular filtration rate (GFR) above 60 ml/minute per 1.73m2. Currently used estimating equations are poor at identifying early renal impairment and better indices are of great interest (15, 16). Recently, several studies have suggested that cystatin-C levels may be a more sensitive marker of early renal impairment than either albuminuria or serum creatinine concentration (17-20). Therefore, a better understanding of a putative role for cystatin-C in the etiology of prediabetes could shed light on the renal/heart disease connection (21). Given the reported superiority of cystatin C over conventional measures of renal function, we hypothesized that cystatin-C would predict progression to prediabetes independent of serum creatinine or estimated GFR. We also investigated the role of intervening mechanisms including hypertension, insulin resistance, endothelial dysfunction and inflammation

    EXPERIMENTAL STUDY OF THE INLET FLOW IN A NON-PREMIXED COMBUSTION CHAMBER

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    The evaluation, validation and development of the models used in computation fluid dynamics requires the availability of experimental data for which the boundary conditions, especially the conditions of the inlet flow, are well defined. Laser diagnostics techniques provide experimental data used in computational fluid dynamics and are a powerful tool for measurements of the mean properties and fluctuations of the turbulent flow because they are non-intrusive methods, with high repetition rate and high spatial and temporal resolution. Therefore, in the present work an experimental study of the inlet flow (inert and combusting flows) in a non-premixed combustion chamber is presented. The velocity measurements were carried out using a laser Doppler velocimeter at the entrance region of the combustion chamber. An asymmetry on the mean flow and an increase on the total velocity fluctuations with the increase of the equivalence ratio was observed. The major effect on the increase of the equivalence ratio was a presence of a coherent movement on large scales associated to the flame brush dynamics

    On the Creation of the Universe out of Nothing

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    We explain how the Universe was created with no expenditure of energy or initial mass.Comment: To be presented at IWARA 2009 (4th International Workshop on Astronomy and Relativistic Astrophysics), to be held in Brazil, October 200

    Lagarta-dos-cafezais: o caso de Rondônia.

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    Nesta publicação verificou-se a existência de 64 propriedades com 618 hectares afetados pelo ataque da lagarta-dos-cafezais no município de Cacoal-RO e as medidas de controle adotadas para conter a expansão de E. imperialis com a redução significativa da área atacada.bitstream/item/72102/1/0000004037-ct68-lagartadoscafezais.pd
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