Kin-Aggregations Explain Chaotic Genetic Patchiness, a Commonly Observed Genetic Pattern, in a Marine Fish

The phenomenon of chaotic genetic patchiness is a pattern commonly seen in marine organisms, particularly those with demersal adults and pelagic larvae. This pattern is usually associated with sweepstakes recruitment and variable reproductive success. Here we investigate the biological underpinnings of this pattern in a species of marine goby Coryphopterus personatus. We find that populations of this species show tell-tale signs of chaotic genetic patchiness including: small, but significant, differences in genetic structure over short distances; a non-equilibrium or “chaotic” pattern of differentiation among locations in space; and within locus, within population deviations from the expectations of Hardy-Weinberg equilibrium (HWE). We show that despite having a pelagic larval stage, and a wide distribution across Caribbean coral reefs, this species forms groups of highly related individuals at small spatial scales (metres). These spatially clustered family groups cause the observed deviations from HWE and local population differentiation, a finding that is rarely demonstrated, but could be more common than previously thought

Remoção de fósforo de efluentes da suinocultura.

Projeto/Plano de Ação: 03.11.09.01

Tecnologias para tratamento de dejeto de suínos.

Projeto/Plano de Ação: 03.11.09.012

Onset of Convection in Two Liquid Layers with Phase Change

We perform linear stability calculations for horizontal fluid bilayers that can undergo a phase transformation, taking into account both buoyancy effects and thermocapillary effects in the presence of a vertical temperature gradient. We compare the familiar case of the stability of two immiscible fluids in a bilayer geometry with the less-studied case that the two fluids represent different phases of a single-component material, e.g., the water-steam system. The two cases differ in their interfacial boundary conditions: the condition that the interface is a material surface is replaced by the continuity of mass flux across the interface, together with an assumption of thermodynamic equilibrium that in the linearized equations represents the Clausius-Clapeyron relation relating the interfacial temperature and pressures. For the two-phase case, we find that the entropy difference between the phases plays a crucial role in determining the stability of the system. For small values of the entropy difference between the phases, the two-phase system can be linearly unstable to either heating from above or below. The instability is due to the Marangoni effect in combination with the effects of buoyancy (for heating from below). For larger values of the entropy difference the two-phase system is unstable only for heating from below, and the Marangoni effect is masked by effects of the entropy difference. To help understand the mechanisms driving the instability on heating from below we have performed both long-wavelength and short-wavelength analyses of the two-phase system. The short-wavelength analysis shows that the instability is driven by a coupling between the flow normal to the interface and the latent heat generation at the interface. The mechanism for the large wavelength instability is more complicated, and the detailed form of the expansion is found to depend on the Crispation and Bond numbers as well as the entropy difference. The two-phase system allows a conventional Rayleigh-Taylor instability if the heavier fluid overlies the lighter fluid; applying a temperature gradient allows a stabilization of the interface

Compact Labelings For Efficient First-Order Model-Checking

We consider graph properties that can be checked from labels, i.e., bit sequences, of logarithmic length attached to vertices. We prove that there exists such a labeling for checking a first-order formula with free set variables in the graphs of every class that is \emph{nicely locally cwd-decomposable}. This notion generalizes that of a \emph{nicely locally tree-decomposable} class. The graphs of such classes can be covered by graphs of bounded \emph{clique-width} with limited overlaps. We also consider such labelings for \emph{bounded} first-order formulas on graph classes of \emph{bounded expansion}. Some of these results are extended to counting queries

Locally constrained homomorphisms on graphs of bounded treewidth and bounded degree.

A homomorphism from a graph G to a graph H is locally bijective, surjective, or injective if its restriction to the neighborhood of every vertex of G is bijective, surjective, or injective, respectively. We prove that the problems of testing whether a given graph G allows a homomorphism to a given graph H that is locally bijective, surjective, or injective, respectively, are NP-complete, even when G has pathwidth at most 5, 4 or 2, respectively, or when both G and H have maximum degree 3. We complement these hardness results by showing that the three problems are polynomial-time solvable if G has bounded treewidth and in addition G or H has bounded maximum degree

Avaliação pré-operatória dos testes cutâneos de hipersensibilidade retardada e da linfocitometria em pacientes com carcinoma epidermóide de esôfago

OBJECTIVE: Cutaneous tests for delayed hipersensivity have been used for differentiating preoperative immunologic status so as to determine nutritional performance. The aim of this study was to evaluate the immunologic status of patients with squamous cell carcinoma of the esophagus.PATIENTS AND METHODS: Delayed hipersensivity and lymphocytometry were preoperatively assessed in 45 patients with squamous cell carcinoma (cases) and90 patients with common surgical diseases (controls).RESULTS: Comparison of weight loss between the two groups showed that the case group was significantly more malnourished than the controls (P = 0.001). None of the cutaneous tests used (candidin, varidase, tricofitin, and tuberculin) showed statistical significance (P = NS) when the two groups were compared. There was statistical difference (P = 0.002) in lymphocytometry with a significant decrease of lymphocyte counts in the control group.CONCLUSIONS: The authors conclude that the cutaneous tests for delayed hipersensitivity were of little application for differentiating preoperative immunologicstatus to determine nutritional performance, while lymphocytometry seems to be a reliable test to evaluate cellular immunity in patients with squamous cell carcinoma. Lymphocytometry may be used as an additional test to assess malnutrition in these patients.OBJETIVO: Os testes cutâneos de hipersensibilidade retardada e a linfocitometria têm sido usados para determinação do estado imunológico de pacientes com câncer, relacionando suas alterações à piora do estado nutricional. O objetivo desse estudo foi avaliar o estado imunológico dos pacientes com carcinoma epidermóide de esôfago, determinando-se um perfil imunológico. PACIENTES E MÉTODOS: Foram estudados 45 pacientes com carcinoma epidermóide de esôfago (casos) e 90 pacientes com outras doenças cirúrgicas(controles) através dos testes cutâneos de hipersensibilidade retardada e da linfocitometria.RESULTADOS: A comparação entre os grupos em relação à perda de peso demonstrou que o grupo dos casos era estatisticamente mais desnutrido que oscontroles (P = 0.001). Nenhum dos testes cutâneos de hipersensibilidade retardada utilizados (candidina, varidase, tricofitina e tuberculina) apresentou diferençaestatisticamente significativa (P = NS) quando se compararam os dois grupos. Houve diferença estatística (P = 0.002) em relação à linfocitometria, com diminuiçãosignificativa da contagem de linfócitos nos pacientes com carcinoma epidermóide de esôfago.CONCLUSÕES: Os autores concluem que os testes cutâneos de hipersensibilidade retardada foram de pouca utilidade para diferenciar o estado imunológico préoperatório em ambos grupos estudados. Por outro lado, a linfocitometria demonstrou ser um bom método de avaliação da imunidade celular em pacientes com carcinoma epidermóide de esôfago, podendo ser utilizado como mais um teste para caracterizar desnutrição nesse grupo de pacientes

Indução de aderência intrabdominal por prótese de retícula de polipropileno:: estudo experimental em ratos

INTRODUCTION: The correction of groin hernias using a transperitoneal videolaparoscopic method with a polypropylene mesh is becoming increasingly common. This could lead to an increased incidence of adhesion formation.MATERIALS AND METHODS: The incidence of adhesions induced by mesh placement and by reperitonization was observed in 40 male adult Wistar rats, randomlyallocated to four groups of 10 rats (Group A = no mesh, no reperitonization; B = no mesh, reperitonization; C = mesh, no reperitonization; D = mesh and reperitonization). After opening the abdominal cavity, the iliac fossa was identified and a peritoneal opening, measuring about 2 by 2 cm, was done on the parietal wall. In the rats in which a polypropylene prosthesis was used, a piece of Marlex mesh, measuring about 1.5 by 1.5 cm was placed on the peritoneal opening. A simple suture was performed in the animals submitted to reperitonization, using a 5.0 monofilamentar polypropylene thread on a cardiovascular (atraumatic) needle. The animals were killed 15 days after the operation. Macroscopic analysis was done by an investigator blinded to intervention group. Fisher’s exact test and the c2 test were used for statistical analysis of the results. A P < 0.05 was considered as significant.RESULTS: Adhesions were significantly more common in the groups in which the prosthesis was placed (59% vs. 95%; P = 0.01), as well as in the groups in whichreperitonization was performed (58% vs. 100%; P = 0.03).CONCLUSIONS: The results suggest that polypropylene mesh placement and reperitonization are each independent factors that have a role in inducing the formationof adhesions.INTRODUÇÃO: A correção de hérnias na virilha através de um método videolaparoscópico transperitoneal está se tornando cada vez mais comum. Contudo,este método poderia levar a um aumento na incidência de formação de aderências.MATERIAIS E MÉTODOS: A incidência de aderências induzidas pela colocação de retícula e pela reperitonização foram observadas em 40 ratos Wistar adultos, machos, divididos aleatoriamente em quatro grupos com 10 ratos cada um (Grupo A = sem retícula, sem reperitonização; B = sem retícula, com reperitonização; C = com retícula, sem reperitonização; D = retícula e reperitonização). Após a abertura da cavidade abdominal, a fossa ilíaca foi identificada e fez-se uma abertura de aproximadamente 2 x 2 cm na parede parietal. Nos ratos em que uma prótese de polipropileno foi utilizada, uma retícula Marlex com 1,5 x 1,5 cm foi colocada sobre a abertura peritoneal. Nos outros animais, a reperitonização foi feita com sutura simples, utilizando-se fio de polipropileno monofilamentar 5.0 com uma agulha cardiovascular (atraumática). Os animais foram sacrificados 15 dias depois da operação. A análise macroscópica foi realizada por um investigador cego quanto ao grupo de origem dos animais. A análise estatística utilizou o teste exato de Fisher e o c2. Um P < 0,05 foi considerado significativo.RESULTADOS: As aderências foram significativamente mais comuns nos grupos nos quais a prótese foi utilizada (59% vs. 95%; P = 0,01), assim como nos gruposnos quais foi feita a reperitonização (58% vs. 100%; P = 0,03).  CONCLUSÕES: Os resultados sugerem que a retícula de polipropileno e a reperitonização são fatores independentes entre si quanto à indução de formaçãode aderências

Induced Disjoint Paths in Circular-Arc Graphs in Linear Time

The Induced Disjoint Paths problem is to test whether a graph G with k distinct pairs of vertices (si,ti) contains paths P1,…,Pk such that Pi connects si and ti for i=1,…,k, and Pi and Pj have neither common vertices nor adjacent vertices (except perhaps their ends) for 1≤