Schwannomas In The Head And Neck: Retrospective Analysis Of 21 Patients And Review Of The Literature.

Schwannomas are benign neoplasms of the peripheral nerves originating in the Schwann cells. According to their cellularity, they can be subdivided into Antoni A or Antoni B types. They are rare and usually solitary, with clearly delimited capsules. They occur in the head and neck region in only 25% of the cases, and may be associated with Von Recklinghausen's disease. The present study retrospectively analyzed some data on this disease in the head and neck region and reviewed the literature on the subject. Retrospective study at Head and Neck Service, Universidade Estadual de Campinas. Data on 21 patients between 1980 and 2003 were reviewed. The sites of cervical schwannomas and the intraoperative, histopathological and postoperative clinical status of these cases were studied. Diagnostic methods, type of surgery and association with neurofibromatosis were evaluated. The patients' ages ranged from 16 to 72 years. Four patients had a positive past history of type I neurofibromatosis or Von Recklinghausen's disease. The nerves affected included the brachial and cervical plexuses, vagus nerve, sympathetic chain and lingual or recurrent laryngeal nerve. The nerve of origin was not identified in six cases. Tumor enucleation was performed in 16 patients; the other five required more extensive surgery. Schwannomas and neurofibromas both derive from Schwann cells, but are different entities. They are solitary lesions, except in Von Recklinghausen's disease. They are generally benign, and rarely recur. The recommended surgical treatment is tumor enucleation.125220-

Using a simple expert system to assist a powered wheelchair user

A simple expert system is described that helps wheelchair users to drive their wheelchairs. The expert system takes data in from sensors and a joystick, identifies obstacles and then recommends a safe route. Wheelchair users were timed while driving around a variety of routes and using a joystick controlling their wheelchair via the simple expert system. Ultrasonic sensors are used to detect the obstacles. The simple expert system performed better than other recently published systems. In more difficult situations, wheelchair drivers did better when there was help from a sensor system. Wheelchair users completed routes with the sensors and expert system and results are compared with the same users driving without any assistance. The new systems show a significant improvement

Community forest management in Indonesia: Avoided deforestation in the context of anthropogenic and climate complexities

Community forest management has been identified as a win-win option for reducing deforestation while improving the welfare of rural communities in developing countries. Despite considerable investment in community forestry globally, systematic evaluations of the impact of these policies at appropriate scales are lacking. We assessed the extent to which deforestation has been avoided as a result of the Indonesian government’s community forestry scheme, Hutan Desa (Village Forest). We used annual data on deforestation rates between 2012 and 2016 from two rapidly developing islands: Sumatra and Kalimantan. The total area of Hutan Desa increased from 750 km2 in 2012 to 2500 km2 in 2016. We applied a spatial matching approach to account for biophysical variables affecting deforestation and Hutan Desa selection criteria. Performance was assessed relative to a counterfactual likelihood of deforestation in the absence of Hutan Desa tenure. We found that Hutan Desa management has successfully achieved avoided deforestation overall, but performance has been increasingly variable through time. Hutan Desa performance was influenced by anthropogenic and climatic factors, as well as land use history. Hutan Desa allocated on watershed protection forest or limited production forest typically led to a less avoided deforestation regardless of location. Conversely, Hutan Desa granted on permanent or convertible production forest had variable performance across different years and locations. The amount of rainfall during the dry season in any given year was an important climatic factor influencing performance. Extremely dry conditions during drought years pose additional challenges to Hutan Desa management, particularly on peatland, due to increased vulnerability to fire outbreaks. This study demonstrates how the performance of Hutan Desa in avoiding deforestation is fundamentally affected by biophysical and anthropogenic circumstances over time and space. Our study improves understanding on where and when the policy is most effective with respect to deforestation, and helps identify opportunities to improve policy implementation. This provides an important first step towards evaluating the overall effectiveness of this policy in achieving both social and environmental goals