Perceptual validation of sound environment reproduction inside an aircraft mock-up.

Auditory comfort evaluations are garnering increased attention in engineering and particularly in the context of air transportation. Being able to produce sound environments corresponding to various flight conditions in aircraft mock-ups would be a valuable tool to investigate acoustic comfort inside aircrafts in controlled environments. Before using such mock-ups, they must be developed and validated in physical and perceptual terms. This paper provides a perceptual validation of sound environment reproduction inside aircraft mock-up. To provide a faithfully reproduced sound environment, time, frequency and spatial characteristics should be preserved. Physical sound field reproduction approaches for spatial sound reproduction are required while properly preserving localization cues at the listener's ears to recreate a realistic and immersing sound environment. We report a perceptual validation of a sound field reproduction system developed in an aircraft mock-up based on multichannel least-square methods and equalization. Twenty participants evaluated reproduced sound environments relative to a reference sound environment in an aircraft cabin mock-up equipped with a 41-actuator multichannel sound reproduction system. Results indicate that the preferred reproduction corresponds to the best physical reconstruction of the sound environment.

Source sparsity control of sound field reproduction using the elastic-net and the lasso minimizers.

Sound field reproduction is aimed at the reconstruction of a sound pressure field in an extended area using dense loudspeaker arrays. In some circumstances, sound field reproduction is targeted at the reproduction of a sound field captured using microphone arrays. Although methods and algorithms already exist to convert microphone array recordings to loudspeaker array signals, one remaining research question is how to control the spatial sparsity in the resulting loudspeaker array signals and what would be the resulting practical advantages. Sparsity is an interesting feature for spatial audio since it can drastically reduce the number of concurrently active reproduction sources and, therefore, increase the spatial contrast of the solution at the expense of a difference between the target and reproduced sound fields. In this paper, the application of the elastic-net cost function to sound field reproduction is compared to the lasso cost function. It is shown that the elastic-net can induce solution sparsity and overcomes limitations of the lasso: The elastic-net solves the non-uniqueness of the lasso solution, induces source clustering in the sparse solution, and provides a smoother solution within the activated source clusters.

[Living with dignity until the end]. / Vivre dans la dignité jusqu'à la fin.

The author of this article tackles some end-of-life issues and presents his thoughts on euthanasia and assisted suicide. He defends the idea of "living with dignity to the end," and sees death itself as a natural process that the client does not always want shortened. Drawing on experience from his palliative care practice the author establishes a link between heroic measures, pain alleviation and false hope. He also encourages ethical debates by framing questions common to the daily work of nurses. The author has unprecedented insight into the nurse's role as an observer of change in the condition of the dying person and her/his interpretation of the needs, fears, happiness and concerns of that person. The author also promotes professional collaboration, without prejudice or discrimination, and the alleviation of pain using the endiess range of palliative precautions. His approach to end-of-life offers a message of hope to the living.

[Nursing interventions can be simple]. / L'intervention: ça peut être si simple!

This article challenges caregivers to reconsider certain barriers that may influence their perception of client care, regardless of the reason for care. Presenting a holistic approach to nursing interventions in palliative care, the author also provides a brief overview of the evolution of caregiving and highlights the increasingly important role of the family. Indeed family involvement forms the basis of the author's approach, an approach that takes into account the bio-psycho-social aspects of care and the sexual well-being of the client. He stresses that the reactions of family members and loved ones to the illness of the client can vary greatly, requiring versatility in the nurse's role as facilitator.

[Music therapy]. / La musicothérapie.

Music stands for the mystical expression of life cycles celebrations: birth, death, renewal of seasons, hunting, rituals of passage... It serves in other familiar conjunctures, such as the dentist chair, waiting rooms and on the telephone, helping us to relax or increase our patience. However, music is not for everyone at all times. With each individual, its significance varies according to the moment and the situation. If a nurse can make use of it with some persons, it is because they have convinced her that music can be of comfort to them and can reduce their pain and anxiety. The role of the caregiver is to attend to the sick by different means. Music is one of them. By being alert and prudent, nurses can provide a care traditionally perpetuated as comforting. Music therapy is the controlled use of music and its elements to help the physiological, psychological and emotional integration of the individual in the course of a treatment for illness or incapacity. Its active mode implies that clients participate by playing an instrument or by singing to express oneself. It opens or maintains the field of communication. In the passive mode, therapists use tapes, disks or interpret pieces of music themselves. Its meaning, its power, take on other dimensions. When introducing music on a palliative care unit, for example, an initial assessment of each client is required to discover and monitor the degree of their acceptance. Thereafter, a continuous evaluation ensures that appropriate adjustments are made in the choice of music offered.(ABSTRACT TRUNCATED AT 250 WORDS)

Shortened platelet survival as a cause of thrombocytopenia in mice with L1210 leukemia.

Thrombocytopenia is a frequent complication of acute leukemias of humans and animals. To define the possible causes of this decrease in platelets, we have studied platelet kinetics in mice after transplantation of 10(6) ascites cells from mice bearing L1210 leukemia. The circulating half-time of 51Cr-labeled platelets was reduced to approximately one-half that of controls when studied 1 or 3 days posttransplantation. Recovery of transfused 51Cr-labeled platelets was reduced to approximately one-half that in controls when studied 3 days after introduction of L1210 cells. Megakaryocyte concentration showed no change during the 5-day survival after i.v. infusion of leukemic cells but was increased on Day 5 and i.p. inoculation with an average host survival of 7 days. Megakaryocyte diameter distributions were significantly shifted toward larger sizes beginning on Day 2 after i.v. inoculation and on Day 3 after i.p. inoculation. Twenty-four-hr [3H]thymidine labeling indices of megakaryocytes were significantly increased beginning on Day 3 after i.v. inoculation but were significantly decreased on Days 5 and 6 after i.p. introduction of L1210 cells. We conclude that the decrease in platelets in mice transplanted with L1210 leukemia results primarily from shortened platelet survival and organ pooling. Megakaryocytes remain normal in concentration but increase in size, a usual response to decreases in platelet count.

Ultrastructure and cytokinetics of leukemic myeloblasts containing giant granules.

Leukemic myeloblasts containing abnormal granules were studied with ultrastructural, cytochemical, and thymidine labeling techniques to evaluate defects in granulogenesis and proliferation. Giant granules (1 to 3 micron in diameter) and Auer rods were observed in leukemic cells from two patients, and only rarely were both abnormal granule types observed in the same cell. The lysosomal origin of these abnormal granules was demonstrated by their content of peroxidase, esterase, and anionic glycoconjugates. Fusion of small dense granules (less than 0.2 micron in diameter) appeared to be increased in cells containing Auer rods and/or giant granules, but fusion of intact primary granules (0.2 to 0.4 micron in diameter) and sequestration of cytoplasmic contents were observed only in giant granules and not in Auer rods. Although the small granules that fused to form giant granules and Auer rods appeared similar, there was no evidence for transformation of giant granules into Auer rods. In one patient, cells with abnormal granules could easily be distinguished from the larger population of cells that lacked abnormal granules. The perturbation of these two distinct populations by chemotherapy was evaluated with thymidine labeling experiments. A high percentage (2- or 3-fold greater) of the abnormally granulated myeloblasts incorporated tritiated thymidine when compared to myeloblasts without abnormal granules in the same specimen. This difference could have resulted from an underlying metabolic defect which affected both granulogenesis and cell division. These results demonstrate that the formation of giant granules in leukemic cells is morphologically similar to that observed in the Chediak-Higashi syndrome and that leukemic cells with abnormal granules may differ cytokinetically from uninvolved leukemic cells.