Algorithmic and Hardness Results for the Colorful Components Problems

In this paper we investigate the colorful components framework, motivated by applications emerging from comparative genomics. The general goal is to remove a collection of edges from an undirected vertex-colored graph $G$ such that in the resulting graph $G'$ all the connected components are colorful (i.e., any two vertices of the same color belong to different connected components). We want $G'$ to optimize an objective function, the selection of this function being specific to each problem in the framework. We analyze three objective functions, and thus, three different problems, which are believed to be relevant for the biological applications: minimizing the number of singleton vertices, maximizing the number of edges in the transitive closure, and minimizing the number of connected components. Our main result is a polynomial time algorithm for the first problem. This result disproves the conjecture of Zheng et al. that the problem is $NP$-hard (assuming $P \neq NP$). Then, we show that the second problem is $APX$-hard, thus proving and strengthening the conjecture of Zheng et al. that the problem is $NP$-hard. Finally, we show that the third problem does not admit polynomial time approximation within a factor of $|V|^{1/14 - \epsilon}$ for any $\epsilon > 0$, assuming $P \neq NP$ (or within a factor of $|V|^{1/2 - \epsilon}$, assuming $ZPP \neq NP$).Comment: 18 pages, 3 figure

Review of the Laguerre-Gauss mode technology research program at Birmingham

Gravitational wave detectors from the advanced generation onwards are expected to be limited in sensitivity by thermal noise of the optics, making the reduction of this noise a key factor in the success of such detectors. A proposed method for reducing the impact of this noise is to use higher-order Laguerre-Gauss (LG) modes for the readout beam, as opposed to the currently used fundamental mode. We present here a synopsis of the research program undertaken by the University of Birmingham into the suitability of LG mode technology for future gravitational wave detectors. This will cover our previous and current work on this topic, from initial simulations and table-top LG mode experiments up to implementation in a prototype scale suspended cavity and high-power laser bench

Substratos no desenvolvimento inicial de quatro cultivares de pessegueiro e uma nectarineira.

Entre os fatores que contribuem para melhor desenvolvimento inicial das plantas, estão a qualidade da semente e o substrato utilizado.Objetivou-se avaliar o efeito do substrato na formação inicial de pessegueiro e nectarineira. O trabalho foi realizado no Departamento de Fitotecnia, da Universidade Federal de Viçosa, de fevereiro a março de 2004. Foram utilizados quatro cultivares de pessegueiro, 'Alô Doçura', 'Campinas 1', 'Relíquia' e 'Ouromel' e uma cultivar de nectarineira 'Josefina'. Sementes retiradas de frutos maturos, foram estratificadas em câmara fria, com temperatura de 5±1ºC e ausência de luz. Após a germinação, no interior da casa-de-vegetação, procedeu-se à semeadura em recipientes plásticos (3 litros), contendo os substratos: Plantmax®; Plantmax® + Areia (1:1 v/v); Plantmax® + Latossolo Vermelho (1:1 v/v); Plantmax® + Latossolo Vermelho + Areia (1:1:1 v/v). Foi utilizado o delineamento experimental inteiramente casualizado, num fatorial 5 x 4 (cultivar x substrato), com cinco repetições, considerando-se como unidade experimental cada recipiente plástico. Após 38 dias da semeadura foram analisadas: porcentagem de emergência, número de folhas, comprimento total, altura e comprimento de raiz, diâmetro do caule, massa da matéria seca total, da parte aérea e da raiz e o número de brotações primárias. O substrato teve efeito no desenvolvimento inicial de pessegueiro, obtendo-se os melhores resultados com o substrato comercial Plantmax®. O maior acúmulo de massa de matéria seca total e da parte aérea foi obtido com os cultivares 'Campinas 1' e 'Relíquia', sendo que esse último, também proporcionou maior número de brotações primárias

Variabilidade genética em populações naturais de umbuzeiro (Spondias tuberosa Arr. Cam.) com base em dados isoenzimáticos.

Este trabalho teve como objetivo quantificar a variabilidade genética em duas populações naturais de umbuzeiro (fruteira endêmica do semi-árido nordestino) e sua distribuição entre e dentro das populações, de forma a fornecer dados que direcionem a coleta de germoplasma para conservação e melhoramento genético da espécie

Antiprotons Annihilation in the Galaxy As A Source of Diffuse Gamma Background

The existence of antimatter domains in baryon asymmetrical Universe can appear as the cosmological consequence of particle theory in inflationary models with non-homogeneous baryosynthesis. Such a domain can survive in the early Universe and form globular cluster of antimatter stars in our Galaxy. The model of antimatter pollution of Galaxy and annihilation with matter gas is developed. The proton-antiproton annihilation gamma flux is shown to reproduce the observed galactic gamma background measured by EGRET. From comparison with observational data the estimation on the maximally allowed amount of antimatter stars, possibly present in our Galaxy, is found.Comment: LaTeX2e, 18 pages, 3 PostScript figures. Submitted to Yad.Fi

Diversidade genética entre progênies de maracujazeiro amarelo baseado em características morfo agronômicas.

O estudo da diversidade genética é básico para subsidiar a escolha de genitores e trabalhos de seleção e melhoramento. Este trabalho foi realizado no Departamento de Fitotecnia da Universidade Federal de Viçosa. Avaliouse a diversidade genética entre 34 famílias de meios-irmãos e 3 cultivares de maracujazeiro amarelo. O delineamento experimental foi em blocos casualizados, com 37 tratamentos, três repetições e quatro plantas por parcela. As características avaliadas foram: altura da planta e diâmetro do caule aos 60 dias após o transplantio, diâmetro do caule no início da produção, vigor, severidade de verrugose e produção por parcela. Os dados foram submetidos à análise de variância e as médias comparadas pelo método de Dunnett. Para o estudo da diversidade genética, foram estimadas as distâncias de Mahalanobis (D2) entre progênies, bem como realizadas análises de agrupamento de Tocher e das Variáveis Canônicas. Por meio da análise de variância, verificou-se efeito dos tratamentos em todas as variáveis, evidenciando a existência de variabilidade genética entre as progênies e cultivares avaliados. Houve concordância na formação dos grupos de similaridade por meio dos diferentes métodos de análise multivariada. Os grupos de tratamentos divergentes entre si e superiores foram: Grupo I - 2, 3, 6 e 15; Grupo II - 14; e Grupo III - 25

Mixed composition materials suitable for vacuum web sputter coating

Ion beam sputter deposition techniques were used to investigate simultaneous sputter etching of two component targets so as to produce mixed composition films. Although sputter deposition has been largely confined to metals and metal oxides, at least one polymeric material, poly-tetra-fluorethylene, has been demonstrated to produce sputtered fragments which repolymerize upon deposition to produce a highly cross-linked fluoropolymer resembling that of the parent target Fluoropolymer-filled silicon dioxide and fluoropolymer-filled aluminum oxide coatings have been deposited by means of ion beam sputter coat deposition resulting in films having material properties suitable for aerospace and commercial applications. The addition of fluoropolymer to silicon dioxide films was found to increase the hydrophobicity of the resulting mixed films; however, adding fluoropolymer to aluminum oxide films resulted in a reduction in hydrophobicity, thought to be caused by aluminum fluoride formation

Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients The ROADMAP Study 2-Year Results

OBJECTIVES The authors sought to provide the pre-specified primary endpoint of the ROADMAP (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients) trial at 2 years. BACKGROUND The ROADMAP trial was a prospective nonrandomized observational study of 200 patients (97 with a left ventricular assist device [LVAD], 103 on optimal medical management [OMM]) that showed that survival with improved functional status at 1 year was better with LVADs compared with OMM in a patient population of ambulatory New York Heart Association functional class IIIb/IV patients. METHODS The primary composite endpoint was survival on original therapy with improvement in 6-min walk distance \u3e= 75 m. RESULTS Patients receiving LVAD versus OMM had lower baseline health-related quality of life, reduced Seattle Heart Failure Model 1-year survival (78% vs. 84%; p = 0.012), and were predominantly INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profile 4 (65% vs. 34%; p \u3c 0.001) versus profiles 5 to 7. More LVAD patients met the primary endpoint at 2 years: 30% LVAD versus 12% OMM (odds ratio: 3.2 [95% confidence interval: 1.3 to 7.7]; p = 0.012). Survival as treated on original therapy at 2 years was greater for LVAD versus OMM (70 +/- 5% vs. 41 +/- 5%; p \u3c 0.001), but there was no difference in intent-to-treat survival (70 +/- 5% vs. 63 +/- 5%; p = 0.307). In the OMM arm, 23 of 103 (22%) received delayed LVADs (18 within 12 months; 5 from 12 to 24 months). LVAD adverse events declined after year 1 for bleeding (primarily gastrointestinal) and arrhythmias. CONCLUSIONS Survival on original therapy with improvement in 6-min walk distance was superior with LVAD compared with OMM at 2 years. Reduction in key adverse events beyond 1 year was observed in the LVAD group. The ROADMAP trial provides risk-benefit information to guide patient- and physician-shared decision making for elective LVAD therapy as a treatment for heart failure. (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients [ROADMAP]; NCT01452802

Nutrition Intervention to Decrease Symptoms in Patients With Advanced Heart Failure

For a majority of patients with advanced heart failure, there is a need for complementary, non-pharmacologic interventions that could be easily implemented by health care providers to provide palliative care. Three major pathologic pathways underlying heart failure symptoms have been identified: fluid overload, inflammation, and oxidative stress. Prior research has demonstrated that three nutrients-sodium, omega-3 fatty acids, and lycopene-can alter these pathologic pathways. Therefore, the purposes of this study are to test the effects of a 6-month nutrition intervention of dietary sodium reduction combined with supplementation of lycopene and omega-3 fatty acids on heart failure symptoms, health-related quality of life, and time to heart failure rehospitalization or all-cause death. The aims of this double blind-placebo controlled study are (1) to determine the effects of a 6-month nutrition intervention on symptom burden (edema, shortness of air, and fatigue) and health-related quality of life at 3 and 6 months, and time to heart failure rehospitalization or all-cause death over 12 months from baseline; (2) compare dietary sodium intake, inflammation, and markers of oxidative stress between the nutrition intervention group and a placebo group at 3 and 6 months; and (3) compare body weight, serum lycopene, and erythrocyte omega-3 index between the nutrition intervention group and a placebo group at 3 and 6 months. A total of 175 patients with advanced heart failure will be randomized to either the nutrition intervention or placebo group