6,045 research outputs found

    Data_Sheet_2_The usability of virtual reality to train individuals in responding to behaviors related to dementia.pdf

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    IntroductionDementia is associated with several behavioral changes globally referred to as Behavioral and Psychological Symptoms of Dementia (BPSD) of which many are recognized to be the expression of unmet needs triggered by environmental factors. BPSD are an extreme source of stress for family care partners and health care providers alike and can be the reason why people living with dementia (PLWD) are placed in long-term care homes (LTCH). The overall goal of this project was to examine whether a virtual environment that includes a virtual LTCH resident with dementia in a lifelike situation could be useful and usable for health care providers and care partners to identify potential triggers to BPSDs while being engaged emotionally with the scenario.MethodsTwenty-three health care professionals working with PLWD, 25 care partners to PLWD, 27 students in a health-related field, and 11 university/community college faculty members teaching courses relevant to gerontology tested the application which depicted a meal-time scenario. In addition to being asked about the behavioral triggers in the scene, participants were asked about the usefulness and usability of the tool for training. Presence and simulator sickness were also measured.ResultsResults suggest that participants generally felt present and emotionally engaged. They could identify the potential triggers for the observed behaviors in the virtual human with dementia as well as suggest some solutions. The majority (87% of participants) found the tool easy to use. Many participants identified the inability to interact with the virtual humans as a shortfall, and few reported mild to moderate levels of simulator sickness.DiscussionAs the behavioral changes associated with dementia can cause extreme stress for those interacting with PLWD, developing an effective and efficient training tool could significantly improve well-being for all involved. The investigators see the development and testing of an interactive version of this virtual environment as a next step in making this a clinically relevant training tool.</p

    Data_Sheet_1_The usability of virtual reality to train individuals in responding to behaviors related to dementia.pdf

    No full text
    IntroductionDementia is associated with several behavioral changes globally referred to as Behavioral and Psychological Symptoms of Dementia (BPSD) of which many are recognized to be the expression of unmet needs triggered by environmental factors. BPSD are an extreme source of stress for family care partners and health care providers alike and can be the reason why people living with dementia (PLWD) are placed in long-term care homes (LTCH). The overall goal of this project was to examine whether a virtual environment that includes a virtual LTCH resident with dementia in a lifelike situation could be useful and usable for health care providers and care partners to identify potential triggers to BPSDs while being engaged emotionally with the scenario.MethodsTwenty-three health care professionals working with PLWD, 25 care partners to PLWD, 27 students in a health-related field, and 11 university/community college faculty members teaching courses relevant to gerontology tested the application which depicted a meal-time scenario. In addition to being asked about the behavioral triggers in the scene, participants were asked about the usefulness and usability of the tool for training. Presence and simulator sickness were also measured.ResultsResults suggest that participants generally felt present and emotionally engaged. They could identify the potential triggers for the observed behaviors in the virtual human with dementia as well as suggest some solutions. The majority (87% of participants) found the tool easy to use. Many participants identified the inability to interact with the virtual humans as a shortfall, and few reported mild to moderate levels of simulator sickness.DiscussionAs the behavioral changes associated with dementia can cause extreme stress for those interacting with PLWD, developing an effective and efficient training tool could significantly improve well-being for all involved. The investigators see the development and testing of an interactive version of this virtual environment as a next step in making this a clinically relevant training tool.</p

    Tensile strength and failure behavior of rock-mortar interfaces: Direct and indirect measurements

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    The tensile strength at the rock-concrete interface is one of the crucial factors controlling the failure mechanisms of structures, such as concrete gravity dams. Despite the critical importance of the failure mechanism and tensile strength of rock-concrete interfaces, understanding of these factors remains very limited. This study investigated the tensile strength and fracturing processes at rock-mortar interfaces subjected to direct and indirect tensile loadings. Digital image correlation (DIC) and acoustic emission (AE) techniques were used to monitor the failure mechanisms of specimens subjected to direct tension and indirect loading (Brazilian tests). The results indicated that the direct tensile strength of the rock-mortar specimens was lower than their indirect tensile strength, with a direct/indirect tensile strength ratio of 65%. DIC strain field data and moment tensor inversions (MTI) of AE events indicated that a significant number of shear microcracks occurred in the specimens subjected to the Brazilian test. The presence of these shear microcracks, which require more energy to break, resulted in a higher tensile strength during the Brazilian tests. In contrast, microcracks were predominantly tensile in specimens subjected to direct tension, leading to a lower tensile strength. Spatiotemporal monitoring of the cracking processes in the rock-mortar interfaces revealed that they show AE precursors before failure under the Brazilian test, whereas they show a minimal number of AE events before failure under direct tension. Due to different microcracking mechanisms, specimens tested under Brazilian tests showed lower roughness with flatter fracture surfaces than those tested under direct tension with jagged and rough fracture surfaces. The results of this study shed light on better understanding the micromechanics of damage in the rock-concrete interfaces for a safer design of engineering structures

    Separation of Conjoined Twins Utilizing Cardiopulmonary Bypass

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    The incidence of conjoined twins occurs once in every two million live births. Successful separation has occurred in 50% of these patients. Previous attempts to separate twins at the sagittal sinus have resulted in death. On September 5, 1987, the team at Johns Hopkins Hospital was the first to successfully separate conjoined twins at the sagittal sinus. One key to this success was the use of cardiopulmonary bypass, deep hypothermia and circulatory arrest. Each patient was cannulated with a 14 Fr. aortic cannula and a 22 Fr. venous cannula in the right atrium. They were then connected to completely separate cardiopulmonary bypass circuits. Cardiopulmonary bypass was initiated utilizing a roller pump, pediatric membrane oxygenator with integral cardiotomy, and an arterial filter. The twins were cooled to 20 degrees centigrade in preparation for circulatory arrest. During circulatory arrest, separation occurred and repair was accomplished utilizing direct suture and pericardial patches. When repair was complete, cardiopulmonary bypass was resumed and rewarming begun. At a rectal temperature of 33 degrees centigrade, cardiopulmonary bypass was discontinued. The two major benefits of extra-corporeal circulation in this procedure were maintaining hemodynamic stability and the ability to regulate metabolic demands. The use of cardiopulmonary bypass was a solution to the obstacles presented. The ability to control blood flow, temperature and volume resulted in a successful separation of these patients

    Descending Aortic Aneurysm Repair Utilizing Moderate Hypothermia (30°C) in Conjunction with Left Heart Bypass

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    Thoracic and thoracoabdominal aortic aneurysm repair are frequently associated with ischemic paraplegia, renal failure and death. In order to decrease the incidence of ischemic events and allow for a longer aortic cross clamp time, we combined our previous technique of segmental sequential repair, left heart bypass and cerebral spinal fluid drainage in conjunction with moderate hypothermia (30°C). Twenty-seven adult patients underwent elective thoracic (n=6) or thoracoabdominal (n=21) aortic aneurysm repair from January 1992 to September 1993 utilizing this hypothermic technique. A heat exchanger was integrated in the centrifugal left heart bypass circuit to achieve moderate hypothermia (30°C) and regain normothermia (37°C) prior to partial bypass termination. Cannulation for left heart bypass was aortafemoral artery (n=10) or left atrium-femoral artery (n=17). The surgical technique of segmental sequential repair helps to minimize visceral, kidney and spinal cord ischemia. Among these 27 patients, one developed delayed paraplegia on postoperative day #3 and three suffered postoperative death. The average aortic cross clamp time was 76 ± 7 minutes. Previous studies have demonstrated a significant increase of ischemic morbidity (11-25%) when cross clamp times exceeded 30 minutes. We conclude that the combination of left heart bypass, moderate hypothermia and cerebral spinal fluid drainage allow for a longer duration of aortic cross clamp time and a relatively low incidence of ischemic complications

    La violence fondatrice

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    Heparin Resistance in the Pre-Cardiotomy Patient

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    Patients who undergo heart surgery utilizing cardiopulmonary bypass are systematically anticoagulated with heparin. Heparin is also used for anticoagulation in patients with myocardial infarctions. A discrepancy has been observed in reactivity to heparin in the operating room between patients who are on intravenous heparin and those who are not. A comparison study utilizing 40 patients was performed. Group A consisted of 20 patients who had no heparin therapy history preoperatively. Group B consisted of 20 patients who had been on intravenous heparin therapy for up to four hours prior to their surgery. All patients were coronary artery bypass grafting candidates and were heparinized for cardiopulmonary bypass, utilizing a 3000u/kg protocol with a target activated clotting time (ACT) of 480 seconds. Heparin lot numbers were evenly distributed between the two groups. Group A demonstrated a mean post heparin bolus ACT or 541 seconds, while group B showed a mean ACT or 358 seconds. The nonheparin therapy patients required a mean additional perioperative heparin dose of 3,800 units to maintain the ACT above 480 seconds. The heparin therapy patients had a mean additional dose or 16,500 units. Patients who receive IV heparin therapy prior to cardiopulmonary bypass may require additional heparin to adequately anticoagulate them for extracorporeal circulation

    Locked up Inside the Vessels: Rare Earth Elements Are Transferred and Stored in the Conductive Tissues of the Accumulating Fern Dryopteris erythrosora

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    International audienceRare earth elements (REEs) are strategic metals strongly involved in low-carbon energy conversion. However, these emerging contaminants are increasingly disseminated into ecosystems, raising concern regarding their toxicity. REE-accumulating plants are crucial subjects to better understand REE transfer to the trophic chain but are also promising phytoremediation tools. In this analysis, we deciphered REE accumulation sites in the REE-accumulating fern Dryopteris erythrosora by synchrotron X-ray ÎĽfluorescence (ÎĽXRF). This technique allows a high-resolution and in situ analysis of fresh samples or frozen-hydrated cross sections of different organs of the plant. In the sporophyte, REEs were translocated from the roots to the fronds by the xylem sap and were stored within the xylem conductive system. The comparison of REE distribution and accumulation levels in the healthy and necrotic parts of the frond shed light on the differential mobility between light and heavy REEs. Furthermore, the comparison emphasized that necrotized areas were not the main REE-accumulating sites. Finally, the absence of cell-to-cell mobility of REEs in the gametophyte suggested the absence of REE-compatible transporters in photosynthetic tissues. These results provide valuable knowledge on the physiology of REE-accumulating ferns to understand the REE cycle in biological systems and the expansion of phytotechnologies for REE-enriched or -contaminated soils

    Artificial Rocks Made from Dredged Sands of the Magdalen Islands (Canada): Preliminary Study

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    The consumption of natural materials for construction purpose is increasing each year while the resources are limited. To reduce the environmental burden and efficiently optimize resources, the use of local and alternative resources as building materials is necessary. This solution is not always convenient, especially for the isolated places like islands, and the Magdalen Islands in Quebec are not an exception. Those islands are currently in a shortage of granular materials and must import them, which represents considerable economic and environmental costs. The general goal of this contribution is to take advantage of the local dredged sands, to be reused in civil engineering infrastructures. This study explores the feasibility of consolidated sandy sediments as an artificial rock, which may serve as mass elements for coastal protection against erosio

    L’école de l’humilité

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