The 2-period balanced traveling salesman problem

In the 2-period Balanced Traveling Salesman Problem (2B-TSP), the customers must be visited over a period of two days: some must be visited daily, and the others on alternate days (even or odd days); moreover, the number of customers visited in every tour must be balancedâ, i.e. it must be the same or, alternatively, the difference between the maximum and the minimum number of visited customers must be less than a given threshold. The salesman's objective is to minimize the total distance travelled over the two tours. Although this problem may be viewed as a particular case of the Period Traveling Salesman Problem, in the 2-period Balanced TSP the assumptions allow for emphasizing on routing aspects, more than on the assignment of the customers to the various days of the period. The paper proposes two heuristic algorithms particularly suited for the case of Euclidean distances between the customers. Computational experiences and a comparison between the two algorithms are also given.

A new algorithm for the 2-period Balanced Traveling Salesman Problem in Euclidean graphs

In a previous paper, we proposed two heuristic algorithms for the euclidean 2-period Balanced Travelling Salesman Problem (2B-TSP). In this problem, which arises from a similar one introduced by Butler et al., a certain number of customers must be visited at minimum total cost over a period of two days: some customers must be visited daily, and the others on alternate days (even or odd days). Moreover, the number of customers visited in every tour must be ‘balanced’, i.e. it must be the same or, alternatively, the difference between the maximum and the minimum number of visited customers must be less than a given threshold: this kind of constraint does not appear explicitly in the paper by Butler. In this paper a third algorithm is presented which overcomes some inadequacy of the algorithm A2 we proposed in the previous paper. The new algorithm’s performance is then analyzed, with respect particularly with the first proposed algorithm.period routing problem, period travelling salesman problem, logistic, heuristic algorithms

Effects of electroacupuncture on stress and anxiety-related responses in rats

The aim of this work was to investigate if eletroacupuncture at PC6 would modulate the stress-induced anxiety-like behavior and the level of activation of several brain areas. Rats were distributed in groups: control; submitted to immobilization; submitted to immobilization and eletroacupuncture at PC6 or at the tail. Immobilization increased grooming and decreased stretched attend postures and the time spent in the open arms of the ele-vated plus-maze. Eletroacupuncture at PC6 or tail canceled the effect of immobilization on grooming and attenuated the stretched attend posture. Immobilization increased Fos-immunoreactivity in the prefrontal cortex, medial and central amygdala, paraventricular and dorsomedial nuclei of the hypothalamus, lateral hypothalamus, dentate gyrus, CA1, CA2 and CA3 hippocampal areas. The activation of paraventricular, dorsomedial nuclei and prefrontal cortex by immobilization was canceled by electroacupuncture at PC6 and attenuated by electroacupuncture in the tail. The activation of the other areas was canceled by electroacupuncture in PC6 or the tail. It is concluded that immobilization induced anxiety-like behavior that was moderately attenuated by eletroacupuncture with difference between the stimulation in PC6 or the rat tail. Eletroacupuncture showed specificity concerning to the attenuation of the effects of immobilization in the CNS areas related to the stress response, anxiety and cardiovascular system.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Fed Sao Paulo, Dept Biociencias, Inst Saude & Soc, Campus Baixada Santista,Rua Silva Jardim 136, BR-11015020 Santos, SP, BrazilUniv Fed Sao Paulo, Dept Biociencias, Inst Saude & Soc, Campus Baixada Santista,Rua Silva Jardim 136, BR-11015020 Santos, SP, BrazilWeb of Scienc

Conservative technique for the removal of implants displaced into maxillary sinus

Introduction: Displaced dental implants into the maxillary sinus are relatively rare. Treatment consists of implant surgical removal. Objective: To present two case reports of the removal of implants displaced into maxillary sinus by a conservative technique. Case report: Report 1: A 44-year-old female sought for treatment complaining about headaches and recurrent sinusitis. In the anamnesis she reported she had been undergone placement of nine maxillary implants, fifteen years ago, with total loss of those elements. At the imaging exams it was possible to observe two displaced implants into the bilateral maxillary sinus, besides radiopaque image on the left maxillary sinus, compatible with maxillary sinusitis. Based on this data, the proposed treatment plan was the removal of the displaced implants through Caldwell Luc approach and sinusotomy in the left side, under general anesthesia. The patient has a follow-up of 6 months without complaints. Report 2: A 42-year-old male was referred to the Surgery and Maxillofacial Traumatology Department for implant removal from the right maxillary sinus. Patient underwent implant installation in the area around 9 months ago. In the computarized tomography it was possible to diagnose the implant migration into the right maxillary sinus. the proposed treatment plan was the removal of the displaced implant via Caldwell Luc Access by repositioning the bony window and sinusotomy. Results: Patient has been with no complaints at 30 days after surgery. Conclusion: The technique has been shown to be effective in treating the condition