Facial Nerve Schwannoma Treatment with Stereotactic Radiosurgery (SRS) versus Resection followed by SRS: Outcomes and a Management Protocol

Background  Stereotactic radiosurgery (SRS) and resection are treatment options for patients with facial nerve schwannomas without mass effect. Objective  This article evaluates outcomes of patients treated with SRS versus resection + SRS. Method  We retrospectively compared 43 patients treated with SRS to 12 patients treated with resection + SRS. The primary study outcome was unfavorable combined endpoint, defined as worsening or new clinical symptoms, and/or tumor radiological progression. SRS (38.81 ± 5.3) and resection + SRS (67.14 ± 11.8) groups had similar clinical follow-ups. Results  At the time of SRS, the tumor volumes of SRS (mean ± standard error; 1.83 ± 0.35 mL) and resection + SRS (2.51 ± 0.75 mL) groups were similar. SRS (12.15 ± 0.08 Gy) and resection + SRS (12.16 ± 0.14 Gy) groups received similar radiation doses. SRS group (42/43, 98%) had better local tumor control than the resection + SRS group (10/12, 83%, p  = 0.04). Most of SRS (32/43, 74%) and resection + SRS (10/12, 83%) group patients reached a favorable combined endpoint following SRS ( p  = 0.52). Considering surgical associated side effects, only 2/10 patients of the resection + SRS group reached a favorable endpoint ( p  < 0.001). Patients of SRS group, who are > 34 years old ( p  = 0.02), have larger tumors (> 4 mL, 0.04), internal auditory canal (IAC) segment tumor involvement ( p  = 0.01) were more likely to reach an unfavorable endpoint. Resection + SRS group patients did not show such a difference. Conclusion  While resection is still needed for larger tumors, SRS offers better clinical and radiological outcomes compared to resection followed by SRS for facial schwannomas. Younger age, smaller tumors, and non-IAC situated tumors are factors that portend a favorable outcome.

PLIO: a generic tool for real-time operational predictive optimal control of water networks

This paper presents a generic tool, named PLIO, that allows to implement the real-time operational control of water networks. Control strategies are generated using predictive optimal control techniques. This tool allows the flow management in a large water supply and distribution system including reservoirs, open-flow channels for water transport, water treatment plants, pressurized water pipe networks, tanks, flow/pressure control elements and a telemetry/telecontrol system. Predictive optimal control is used to generate flow control strategies from the sources to the consumer areas to meet future demands with appropriate pressure levels, optimizing operational goals such as network safety volumes and flow control stability. PLIO allows to build the network model graphically and then to automatically generate the model equations used by the predictive optimal controller. Additionally, PLIO can work off-line (in simulation) and on-line (in real-time mode). The case study of Santiago-Chile is presented to exemplify the control results obtained using PLIO off-line (in simulation).

The development of experimental procedures for the evaluation of additives to attenuate manure odour, and the impact of these additives on workers, animals and the environment

The objective of this project was to develop a laboratory research protocol to evaluate the effect of additives on manure odour and physico-chemical characteristics, and establish conditions that are representative of those found in farm storage structures (temperature, solids content, pH, ventilation above the manure surface, storage period). The results suggested that system configuration might have an impact on additive effect. An open system should be used when it is recommended that additives be applied in the animal diet or the gutters. Additionally, the surface/depth ratio of the gutter should be respected, since it will impact on the relative importance of the aerobic layer and on ammonia volatilization. On the other hand, a closed system should be used when the additive is applied to the manure storage tank, especially if the tank has a cover. Odour analysis still requires fundamental research to establish reliable procedures and protocols, especially in the area sample collection and dilution levels required to decrease H2S concentration to safe levels for the panellists. Odour analysis should also be conducted in triplicate, because of the possible large experimental error due to dilution, the human factors, and also instrumental error.