27 research outputs found
An Efficient Heuristic for a Discrete Optimization Problem
In this paper we deal with a discrete optimization problem, which, among many other such problems, is computationally intractable. Since the existence of an exact solution algorithm for our problem is highly unlikely, the development of heuristic and approximation algorithms is of a great importance. Here we briefly discuss this issue and describe a robust 2-approximation heuristic that is used for getting an approximation solution for the problem of scheduling jobs with release times and due-dates on a single machine to minimize the maximum job lateness
Heart failure and cardiorenal syndrome: a case report
Cardio-Renal Syndrome (CRS) is a renal dysfunction occurring in a large percentage of pts hospitalised for congestive heart failure (CHF). It is characterised by an excessive fluid retention inside the body, resistance to conventional medical therapy, worsening renal function (WRF) and higher mortality. The prevalence of CRS is likely increased because of the improved survival of HF patients. WRF occurs frequently among hospitalised HFF and is associated with a significantly worse outcome. Clinical features at admission can be used to identify patients at high risk for developing WRF. The clinical case presented concerns a 70-year-old diabetic man with post-ischemic cardiomyopathy and chronic kidney failure, admitted to our division for acute heart failure. During hospitalisation he showed a progressive WRF and resistance to diuretic treatment. After Ultrafiltration treatment there was a progressive clinical improvement. Many treatments have been investigated in order to improve renal function, but none has been demonstrated to improve clinical outcome. Currently Ultrafiltration is reserved to patients with volume overload when traditional medical therapies fail and/or patients become resistant to diuretics
Modelo cognitivo-motivacional para la promoción de la persistencia en Educación Superior: relación entre la organización docente, la competencia del alumnado y el «grit»
The teaching process and the success of learning are closely linked to cognitive and motivational factors. The purpose of this study was to test a multilevel model in higher education students on the relationship between the teaching organization and the dimensions of grit and perceived competence. Participated 3033 students, who answered utility dimension inventories and organization, competition and grit. The results show that at the individual level, the organization by the teaching staff focused on the utility and organization is positively related to the student's scream, this relationship being mediated by the perceived competence. The organizational improvement of the teacher generates student achievements through the positive impact on their competence.«El proceso de enseñanza y el éxito del aprendizaje están estrechamente vinculados a factores cognitivos y motivacionales. Este estudio tuvo como propósito poner a prueba un modelo multinivel en estudiantes de Educación Superior sobre la relación de la organización docente y las dimensiones del grit, mediada por la competencia percibida. Participaron 3.033 estudiantes de cinco países, a los que se les midió la utilidad y organización del docente, la competencia y el grit. Los resultados muestran que, a nivel individual, la organización por parte del profesorado centrada en la utilidad se relacionó positivamente con el grit del estudiante cuando estaba mediada por la competencia percibida. Se sugiere que el profesor mejore su tarea organizativa docente, pues genera mayores logros en el estudiante a través del impacto positivo sobre su competencia
Adjusting scheduling model with release and due dates in production planning
Motivated by the conjecture that an interaction between scheduling and pre-scheduling phases in production planning may give certain benefits, we conduct a detailed study of the optimality conditions and dominance relations for a strongly NP-hard single-machine scheduling model when jobs have release and due-dates and the objective is to minimize maximum job lateness. By exploring the inherent structure of the problem, we establish the optimality conditions when the problem can be efficiently solved. We come to an NP-hard special case of the problem with only two possible job release times, that as we show allows stricter dominance rules and optimality conditions verifiable in polynomial time. The established properties give a potential of a beneficial interaction between scheduling and pre-scheduling phases in production planning, and also provide basic theoretical background for the construction of efficient heuristic and implicit enumerative algorithms
Adolescenti dinanzi al bardo: una ricerca-intervento di death education tra scuole superiori e hospice.
Heart failure and cardiorenal syndrome: a case report
Cardio-Renal Syndrome (CRS) is a renal dysfunction occurring in a large percentage of pts hospitalised for congestive heart failure (CHF). It is characterised by an excessive fluid retention inside the body, resistance to conventional medical therapy, worsening renal function (WRF) and higher mortality. The prevalence of CRS is likely increased because of the improved survival of HF patients. WRF occurs frequently among hospitalised HFF and is associated with a significantly worse outcome. Clinical features at admission can be used to identify patients at high risk for developing WRF. The clinical case presented concerns a 70-year-old diabetic man with post-ischemic cardiomyopathy and chronic kidney failure, admitted to our division for acute heart failure. During hospitalisation he showed a progressive WRF and resistance to diuretic treatment. After Ultrafiltration treatment there was a progressive clinical improvement. Many treatments have been investigated in order to improve renal function, but none has been demonstrated to improve clinical outcome. Currently Ultrafiltration is reserved to patients with volume overload when traditional medical therapies fail and/or patients become resistant to diuretics
Home range dynamics of mountain hare (<em>Lepus timidus</em>) in the Swiss Alps
<strong>Abstract</strong> Little is known on the ecology and behaviour of alpine mountain hare (<em>Lepus timidus</em>). Between 1996 and 1997 we analysed by radiotracking the pattern of space use of 8 mountain hares from the Swiss Alps. We estimated home range size using both the kernel density estimator and the minimum convex polygon. We found smaller ranges (38 ha) compared to those reported for the species in boreal or arctic habitats, but similar to ranges in Scotland. Hares did not use a centre of major activity (core area) and showed high home range overlap, confirming their non-territorial behaviour. Smaller ranges were used during winter compared to the other seasons, whilst no difference in size was found between sexes. <strong>Riassunto</strong> <strong>Dinamica dell'uso dello spazio della lepre bianca (<em>Lepus timidus</em>) nelle Alpi Svizzere</strong> Le informazioni relative all'ecologia e al comportamento della lepre alpina (<em>Lepus timidus</em>) sono ad oggi scarse. In questo studio abbiamo analizzato l'utilizzo dello spazio di una popolazione di lepre bianca sulle Alpi Svizzere. Tra il 1996 e il 1997 sono stati marcati con redio collare 8 individui di lepre alpina. L'<em>home range</em> è stato calcolato utilizzando lo stimatore di densità kernel (KDE) ed il metodo del minimo poligono convesso (MCP). L'ampiezza degli <em>home range</em> (38 ha) è risultata inferiore a quella riportata per la specie in habitat boreali ed artici. ma simile a quella riscontrata in Scozia. All'interno dell <em>home range</em> non è stato rilevato alcun centro di maggiore attività (<em>core area</em>) ed è stata evidenziata una notevole sovrapposizione tra gli stessi, confermando la non territorialità della specie. Le aree frequentate in inverno sono risultate più piccole rispetto alle altre stagioni e non sono state riscontrate differenze tra i sessi
The effect of death education on fear of death amongst Italian adolescents: A nonrandomized controlled study
This study describes the psychological effects of death education in reducing the fear of
death in a large cohort of Italian adolescents. Following the constructs of \u201cdistal defenses\u201d
and \u201cmortality salience\u201d of Terror Management Theory, this research intervention also evaluated the proposition that spirituality and belief in an afterlife could provide an effective
buffer against fear of death. Five hundred thirty-four Italian high school students participated in a school-based death education program with an experimental group and a nonrandomized control condition. Using a pre/post-course design, we assessed fear of death,
alexithymia, and representations of death and spirituality for both groups. Results confirmed
that the course reduced death fears and the representation of death as annihilation while
also enhancing spirituality. In particular, the older participants in the death education course
increased their spirituality and decreased their fear of death, whereas females reduced their
conviction that death was an absolute annihilation. Finally, the structural model suggested
that alexithymia mediates the relationships among fear of death and spirituality; in particular, fear of death predicted more alexithymia and more alexithymia predicted lower
spirituality