Search results for "problems"

Sexual satisfaction in male infertility.

1999

Infertility is proposed to be a continuing stressor for couples suffering from involuntary childlessness. A long duration of the desire for a child and, correspondingly, a longer period of diagnostic and treatment procedures could have a negative impact on sexual satisfaction, thus leading to an unfavorable psychological circuit. The present evaluation should clarify the state of sexual satisfaction and relationships, with relevant parameters in 68 men with fertility problems, of couples with involuntary childlessness. Subjects reported relatively high average levels of present sexual satisfaction with only nonsignificant lower scores (p = .08) compared to recalled sexual satisfaction prior…

Devenir des enfants issus des techniques d’assistance médicale à la procréation

2013

Since the birth of the first baby conceived by in vitro fertilization (IVF) 30 years ago (Louise Brown in 1978), there has been a rapid and constant increase in the number of couples using assisted reproductive technologies (ART). Around four million of children have been born from couples experiencing fertility problems, through the use of ART, comprising roughly 2-3 % of all births in Europe and U.S. That highlights that these modes of fertilization are now well assumed by our societies. However, several questions on health of these children remain to be elucidated. As evoked in this review, even if methodological limitations exist, numerous studies have reported increased risks of birth …

The Hierarchical Mixed Rural Postman Problem: Polyhedral analysis and a branch-and-cut algorithm

2017

[EN] The Hierarchical Mixed Rural Postman Problem is defined on a mixed graph where arcs and edges that require a service are divided into clusters' that have to be serviced in a hierarchical order. The problem generalizes the Mixed Rural Postman Problem and thus is NP-hard. In this paper, we provide a polyhedral analysis of the problem and propose a branch-and-cut algorithm for its solution based on the introduced classes of valid inequalities. Extensive computational experiments are reported on benchmark instances. The exact approach allows to find the optimal solutions in less than 1 hour for instances with up to 999 vertices, 2678 links, and five clusters.

Dealing with Multi-Level Governance and Wicked Problems in Urban Transportation Systems: The Case of Palermo Municipality

2015

Italian New Public Management (NPM) has been mainly characterized by a political orientation toward power decentralization to local governments and privatization of public companies. Nowadays, local utilities in Italy are often run by joint stock companies controlled by public agencies such as Regional and Municipal Administrations. Due to this transformation, these companies must comply with a set of diverse expectations coming from a wide range of stakeholders, related to their financial, competitive and social performance. Such fragmented governance increases the presence of “wicked” problems in the decision-making sphere of these entities. Given this multi-level governance structure, ho…

Variable Neighborhood Search for the Vertex Separation Problem

2012

The vertex separation problem belongs to a family of optimization problems in which the objective is to nd the best separator of vertices or edges in a generic graph. This optimization problem is strongly related to other well-known graph problems; such as the Path-Width, the Node Search Number or the Interval Thickness, among others. All of these optimization problems are NP-hard and have practical applications in VLSI, computer language compiler design or graph drawing. Up to know, they have been generally tackled with exact approaches, presenting polynomial-time algorithms to obtain the optimal solution for speci c types of graphs. However, in spite of their practical applications, these…

Fluorescent chemosensors containing polyamine receptors

2000

Chemosensors have attracted interest in many different scientific fields, such as environmental chemistry, medicine, and the processing and storage of information. These molecular-scale devices have the advantage of working on the same spatial scale as the chemical structures that are responsible for macroscopic behaviour observed in the environment or those associated with health problems. Moreover, they allow the construction of molecular-scale devices for information storage. In this review, we describe a family of chemosensors based on a polyamine receptor and a fluorescent signalling unit. Polyamine receptors are water-soluble ambidentate receptors; they are able to coordinate either m…

De la atención de los problemas de la audición y lenguaje a la logopedia como disciplina

2015

Las dificultades del lenguaje han estado presentes en el ser humano desde la antigüedad. La sensibilización social e institucional hacia este tipo de trastornos ha mejorado lentamente hasta nuestros días. Ya en la Edad Moderna (siglos XVI al XVIII) se informa de educación de sujetos con problemas de lenguaje. Destaca el trabajo de Pedro Ponce de León como precursor del tratamiento estas dificultades. De forma progresiva, se tomó conciencia de la importancia del tratamiento de las dificultades del lenguaje. En los siglos XIX y XX se produce la institucionalización de la atención a personas con trastornos del lenguaje. La Orientación Educativa atiende tradicionalmente esta problemática. Poste…

Medical student ultrasound education: a WFUMB position paper, part I

2019

The introduction of ultrasound into medical student education is well underway in many locations around the world, but is still in its infancy or has yet to begin in others. Proper incorporation of ultrasound education into medical training requires planning and resources, both capital and human. In this article, we discuss the state of the art of ultrasound in medical education throughout the world, as well as various methodologies utilized to improve student education and to incorporate ultrasound into every facet of training. Experiences from various educational systems and available evidence regarding the impact of ultrasound education are summarized. Representing multiple societies and…

Relazioni interpersonali, stati emotivi e autostima in soggetti obesi binge eaters

2009

Formulations for an inventory routing problem

2014

In this paper, we present and compare formulations for the inventory routing problem (IRP) where the demand of customers has to be served, over a discrete time horizon, by capacitated vehicles starting and ending their routes at a depot. The objective of the IRP is the minimization of the sum of inventory and transportation costs. The formulations include known and new mathematical programming formulations. Valid inequalities are also presented. The formulations are tested on a large set of benchmark instances. One of the most significant conclusions is that the formulations that use vehicle-indexed variables are superior to the more compact, aggregate formulations.