Extremal Graph Theory for Metric Dimension and Diameter

A set of vertices $S$ \emph{resolves} a connected graph $G$ if every vertex is uniquely determined by its vector of distances to the vertices in $S$. The \emph{metric dimension} of $G$ is the minimum cardinality of a resolving set of $G$. Let $\mathcal{G}_{\beta,D}$ be the set of graphs with metric dimension $\beta$ and diameter $D$. It is well-known that the minimum order of a graph in $\mathcal{G}_{\beta,D}$ is exactly $\beta+D$. The first contribution of this paper is to characterise the graphs in $\mathcal{G}_{\beta,D}$ with order $\beta+D$ for all values of $\beta$ and $D$. Such a characterisation was previously only known for $D\leq2$ or $\beta\leq1$. The second contribution is to determine the maximum order of a graph in $\mathcal{G}_{\beta,D}$ for all values of $D$ and $\beta$. Only a weak upper bound was previously known

Empathy, morality and psychopathic traits in women

Empathic and moral processing correlates of psychopathic personality have seldom been studied in women. In this study, we experimentally tested associations between psychopathic personality traits and empathic and moral processing in a female sample, and further directly compared them to results from a male sample. We found that high levels of affective-interpersonal traits were associated with diminished affective response to sad and fearful emotions in others; lower propensity to feel moral emotions; higher endorsement of utilitarian solutions to moral dilemmas involving direct harm; and less self-reported difficulty when performing moral decision making. Overall, our findings strengthen the view that the two dimensions of psychopathy make distinct contributions to emotional and moral processing; and demonstrate that, in women, psychopathic personality traits are associated with a similar pattern of empathic and moral processing biases as the one that has been previously reported in men

Investigating associations between empathy, morality and psychopathic personality traits in the general population

Although atypical moral and empathy processing are considered core features of psychopathic personality, little is known about how these constructs are associated with psychopathic traits in the general population. One-hundred and twenty-four adult males from the community were administered the Self-Report Psychopathy Scale 4 Short Form, as well as a wide battery of affect, empathy and morality tasks and questionnaires. Our findings indicate that both core affective-interpersonal, as well as lifestyle-antisocial features of psychopathy are associated with weaker empathic responses to fearful faces. However, only the unique variance of the affective-interpersonal features is associated with weaker empathic response to happy stories, lower propensity to feel empathic concern and less difficulty in making decisions on moral dilemmas. In contrast, the unique variance of the lifestyle-antisocial features is associated with greater propensity to feel empathic concern. These preliminary findings extend previous research and suggest that, while the joint variance between affective-interpersonal and lifestyle-antisocial features might drive some ‘deficits’ associated with psychopathy, there also appears also to be unique ‘deficits’ associated with the core affective-interpersonal features, particularly in relation to affective aspects of moral processing

Maximum rectilinear convex subsets

Let P be a set of n points in the plane. We consider a variation of the classical Erdos-Szekeres problem, presenting efficient algorithms with (formula presented) running time and (formula presented) space complexity that compute: (1) A subset S of P such that the boundary of the rectilinear convex hull of S has the maximum number of points from P, (2) a subset S of P such that the boundary of the rectilinear convex hull of S has the maximum number of points from P and its interior contains no element of P, (3) a subset S of P such that the rectilinear convex hull of S has maximum area and its interior contains no element of P, and (4) when each point of P is assigned a weight, positive or negative, a subset S of P that maximizes the total weight of the points in the rectilinear convex hull of S

Maximum rectilinear convex subsets

Let P be a set of n points in the plane. We consider a variation of the classical Erd\H os-Szekeres problem, presenting efficient algorithms with O(n3) running time and O(n2) space complexity that compute (1) a subset S of P such that the boundary of the rectilinear convex hull of S has the maximum number of points from P, (2) a subset S of P such that the boundary of the rectilinear convex hull of S has the maximum number of points from P and its interior contains no element of P, (3) a subset S of P such that the rectilinear convex hull of S has maximum area and its interior contains no element of P, and (4) when each point of P is assigned a weight, positive or negative, a subset S of P that maximizes the total weight of the points in the rectilinear convex hull of S. We also revisit the problems of computing a maximum area orthoconvex polygon and computing a maximum area staircase polygon, amidst a point set in a rectangular domain. We obtain new and simpler algorithms to solve both problems with the same complexity as in the state of the art

K1,3-covering red and blue points in the plane

We say that a finite set of red and blue points in the plane in general position can be K1, 3-covered if the set can be partitioned into subsets of size 4, with 3 points of one color and 1 point of the other color, in such a way that, if at each subset the fourth point is connected by straight-line segments to the same-colored points, then the resulting set of all segments has no crossings. We consider the following problem: Given a set R of r red points and a set B of b blue points in the plane in general position, how many points of R ¿ B can be K1, 3-covered? and we prove the following results: (1) If r = 3g + h and b = 3h + g, for some non-negative integers g and h, then there are point sets R ¿ B, like {1, 3}-equitable sets (i.e., r = 3b or b = 3r) and linearly separable sets, that can be K1, 3-covered. (2) If r = 3g + h, b = 3h + g and the points in R ¿ B are in convex position, then at least r + b - 4 points can be K1, 3-covered, and this bound is tight. (3) There are arbitrarily large point sets R ¿ B in general position, with r = b + 1, such that at most r + b - 5 points can be K1, 3-covered. (4) If b = r = 3b, then at least 9 8 (r + b- 8) points of R ¿ B can be K1, 3-covered. For r > 3b, there are too many red points and at least r - 3b of them will remain uncovered in any K1, 3-covering. Furthermore, in all the cases we provide efficient algorithms to compute the corresponding coverings

Experimental determination of the boiling heat transfer coefficients of R-134a and R-417a on a smooth copper tube

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Flooded evaporators are widely used as compact cooling units so as to cool liquids. They consist of a shell-and-tube heat exchanger, with the fluid to cool flowing inside the tube bundle and a refrigerant that evaporates over those tubes. Pool boiling on the external surface of the tubes is a very complex process and, therefore, an experimental analysis is required in order to determine the boiling heat transfer coefficients (HTCs). Copper and copper alloys tubes are commonly employed in such heat exchangers, due to their high thermal conductivity and low cost when compared to other materials. On the other hand, refrigeration and air conditioning sectors are undergoing significant changes caused mainly by the necessity of replacing existing refrigerants with more environmentally-friendly ones. This paper reports the work carried out to determine pool boiling HTCs of two HFCs refrigerants, R-134a and R-417A blend on a smooth copper tube with and outer diameter of 18.87 mm, at two saturation temperatures of 10 ºC and 7 ºC. This work has been done experimentally by means of a test rig specifically designed and prepared for the study of these processes. The experimental setup and data acquisition are described, the experimental procedure is explained, the data reduction methodology is detailed and the results are presented and discussed.dc201

Simulation and experimental validation of a helical coil used as condenser in a heat pump for domestic water heating in a tank

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Although the use of helical coils are widely used in engineering applications for heating and cooling production there is little information available about their thermal behavior. The purpose of this work was to simulate the behavior of a helical coil used as condenser in a heat pump for domestic hot water heating in a tank. The simulation was carried out by developing a mathematical model. The mathematical model was implemented in a computer program. The program results were validated against the experimental results obtained by using an experimental set-up. In the paper the mathematical model is detailed, the experimental setup and the experimental procedure are described and the results are presented and discussed.dc201

Long-term clinical effects of ventricular pacing reduction with a changeover mode to minimize ventricular pacing in a general pacemaker population

AIM: Right ventricular pacing (VP) has been hypothesized to increase the risk in heart failure (HF) and atrial fibrillation (AF). The ANSWER study evaluated, whether an AAI-DDD changeover mode to minimize VP (SafeR) improves outcome compared with DDD in a general dual-chamber pacemaker population. METHODS AND RESULTS: ANSWER was a randomized controlled multicentre trial assessing SafeR vs. standard DDD in sinus node disease (SND) or AV block (AVB) patients. After a 1-month run-in period, they were randomized (1 : 1) and followed for 3 years. Pre-specified co-primary end-points were VP and the composite of hospitalization for HF, AF, or cardioversion. Pre-specified secondary end-points were cardiac death or HF hospitalizations and cardiovascular hospitalizations. ANSWER enrolled 650 patients (52.0% SND, 48% AVB) at 43 European centres and randomized in SafeR (n = 314) or DDD (n = 318). The SafeR mode showed a significant decrease in VP compared with DDD (11.5 vs. 93.6%, P < 0.0001 at 3 years). Deaths and syncope did not differ between randomization arms. No significant difference between groups [HR = 0.78; 95% CI (0.48-1.25); P = 0.30] was found in the time to event of the co-primary composite of hospitalization for HF, AF, or cardioversion, nor in the individual components. SafeR showed a 51% risk reduction (RR) in experiencing cardiac death or HF hospitalization [HR = 0.49; 95% CI (0.27-0.90); P = 0.02] and 30% RR in experiencing cardiovascular hospitalizations [HR = 0.70; 95% CI (0.49-1.00); P = 0.05]. CONCLUSION: SafeR safely and significantly reduced VP in a general pacemaker population though had no effect on hospitalization for HF, AF, or cardioversion, when compared with DDD

Assessing antimicrobial potential of agroindustrial byproducts' extracts produced through solid state fermentation in marine fish

[Excerpt] Sustainability is definitely the 21st century word. The future global food provision is dependent on fish and on sustainable expansion of aquaculture production. For that, alternative nutritional strategies for aquaculture disease management are required, reducing the use of synthetic drugs. Agroindustrial byproducts(brewery, winery and olive oil industry) constitute a circular and ecofriendly potential source of add-value bioactive compounds. Solid state fermentation(SSF) is a biotechnological low cost process that may be applied to these byproducts to effectively increase bioavailability of their bioactive compounds and so their antimicrobial potential against fish pathogens. The aim of this study was to evaluate antibacterial properties of agroindustry(beer, wine and oil processing industries) byproducts' extracts produced through SSF with Aspergillus ibericus. [...]SPO3(ref.POCI-01-0145-FEDER-030377;FCT) & InovFeed(ref. MAR-02.01.01-FEAMP0111;Mar2020)info:eu-repo/semantics/publishedVersio