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In Haiti, and in the Mulet river catchment in particular, environmental degradation is a worrying problem. In order to document the evolution of this catchment, we analysed the dynamics of land use over a 40-year period (1979-2019) using reference Landsat satellite images (1979, 1989, 1999, 2009, 2019) and interviews with farmers. The results show that the catchment has undergone considerable changes. Over the entire study period, agro-sylvo-pastoral systems are the only unit to have declined continuously. Savannahs and dense agricultural crops have increased, but not steadily. Finally, rocky outcrops and bare soil have become increasingly widespread. These transformations were caused by economic constraints (collapse in world coffee and cocoa prices), an uncertain political context since 1986, which has prevented the application of environmental protection measures, and a succession of extreme weather events (droughts, storms, hurricanes). The careless cultivation of new plots on often very steep slopes without taking precaution contributes significantly to soil erosion.

In the context of the sustainable management of the Mulet River watershed, a set of conservation and restoration measures have been identified through a participatory and contributory approach supported by scientific literature. In order to assess these measures according to their overall performance and to bundle them into robust baskets of measures, a multi-criteria decision aid approach in a multi-stakeholder context was employed. This approach allows comparison and ranking of the identified measures while considering the values and the preferences of the various actors involved, in order to facilitate negotiations towards the building of a consensual and shared solution, consisting in baskets of measures. Through the application of this approach leading to a good level of agreement between the actors of the watershed area, several measures of agronomic, plant, mechanical, socio-cultural and socio-political categories were selected, and structured into intervention baskets according to the degredation levels of the watershed. The implementation of these measures aims at making the watershed better adapted to the impacts of climate variability and change, while improving the living conditions of the local communities.

Maladapted agricultural practices in watersheds can lead to socio-ecological disruption. The Mulet river watershed in the department Sud, Haiti was selected as a study case with the objective of analysing the mode of operation of its farms in order to understand the impact of practices implemented in their production systems on the environment and natural resources. In addition to agricultural practices, the watershed is affected by extreme weather event. We conducted a survey of about 30 farm managers and group interviews in the different segments of the watershed (upstream, middle, downstream), in order to understand the link between agricultural practices and the degradation of natural resources (water, soil, wood). Direct field observations were also made. The analysis of our data allows us to understand how the link between agricultural practices, the effects of extreme weather events and the degradation of the watershed and, as a result, the exposure of local residents to natural disasters and food insecurity.

The design, implementation, and characterization of a microelectromechanical systems (MEMS) capacitive accelerometer-based middle ear microphone are presented in this paper. The microphone is intended for middle ear hearing aids as well as future fully implantable cochlear prosthesis. Human temporal bones acoustic response characterization results are used to derive the accelerometer design requirements. The prototype accelerometer is fabricated in a commercial silicon-on-insulator (SOI) MEMS process. The sensor occupies a sensing area of 1 mm × 1 mm with a chip area of 2 mm × 2.4 mm and is interfaced with a custom-designed low-noise electronic IC chip over a flexible substrate. The packaged sensor unit occupies an area of 2.5 mm × 6.2 mm with a weight of 25 mg. The sensor unit attached to umbo can detect a sound pressure level (SPL) of 60 dB at 500 Hz, 35 dB at 2 kHz, and 57 dB at 8 kHz. An improved sound detection limit of 34-dB SPL at 150 Hz and 24-dB SPL at 500 Hz can be expected by employing start-of-the-art MEMS fabrication technology, which results in an articulation index of approximately 0.76. Further micro/nanofabrication technology advancement is needed to enhance the microphone sensitivity for improved understanding of normal conversational speech.

We propose the use of a microelectromechanical system (MEMS) accelerometer as a middle ear microphone for future totally implantable cochlear prostheses. The MEMS accelerometer would be attached to the umbo to detect and convert the natural bone vibration that occurs in response to external sounds into an electrical signal that represents the acoustic information. The signal could be further processed to stimulate cochlear implant electrodes. To determine the feasibility of our proposal, we conducted a study to investigate whether the characteristics of umbo vibration along two orthogonal axes-one axis being perpendicular to the tympanic membrane and the other axis being parallel to the tympanic membrane plane but orthogonal to the long process of the malleus-differ significantly enough to compromise the sensing performance of the proposed accelerometer should a position misalignment occur during the implant procedure. We used laser Doppler vibrometry to measure the displacement of the umbo along the two orthogonal axes in 4 cadaveric temporal bones at multiple frequencies within the audible spectrum. We found that the peak-to-peak displacement frequency response along both axes was nearly flat from 250 Hz to 1 kHz, and it gradually rolled off with a slope of approximately -20 dB and -40 dB per decade above 1 kHz and 4 kHz, respectively. At each frequency, the displacement exhibited a linear function of the input sound level with a slope of 20 dB per decade. A comparison of measurements along the two axes indicated a similar frequency response, with an average amplitude difference of 20%. The characterization data suggest that the performance of a miniature ossicular vibration-sensing device attached on the umbo would not be degraded in the event of a position misalignment. The data also indicate that a MEMS accelerometer needs to achieve a resolution of 35 i g/sqrt[Hz] to detect normal conversation.

System miniaturization and steady progress towards a totally implantable prosthetic system is the current trend in cochlear implant technology. To achieve this objective, the external microphone of present implants needs to be implantable. This goal can be accomplished by placing a miniature accelerometer on the ossicular chain in the middle ear to detect and convert bone vibrations into an electrical signal for further processing and stimulating cochlear electrodes. This paper describes the characterization of the umbo of a human temporal bone before and after the removal of the incus to determine the impact of the resulting change in umbo mechanics and attached accelerometer performance. With the removal of the incus, the umbo vibration acceleration frequency response in the direction perpendicular to the tympanic membrane increases by 5 dB below 2 kHz. Above 2 kHz the response diverges due to the change of ossicular chain resonant frequency caused by the removal of the incus. However, at each frequency the umbo vibration acceleration exhibits a linear function of the input sound pressure level (SPL) with a slope of 20 dB per decade before and after removal of the incus. A commercial accelerometer attached to the umbo shows similar characteristics. From the measurement results of umbo characterization, a miniaturized implantable accelerometer with a packaged mass below 20 milligrams, a sensing resolution of 35 microg rms/square root Hz, and a bandwidth of 10 kHz would be required to detect normal conversation.