1,389 research outputs found
Alpha Model: A Mathematical Modeling Approach Applied to an Air Quality Monitoring Network
n this paper we apply the alpha Model to air quality prediction purposes. This model is used to predict the ground level ozone concentration which is influenced by multiple pollutants such as NO2, CO, Pb and particulate matter. The model was previously elaborated and successfully tested on other complex systems. Our main object here is to show that the alpha model is a powerful technique for analyzing performance complexities of implementing input-output relations. Air quality is taken as an example
Etude de l'évolution physico-chimique et organique d'un fermenteur anaérobie d'ordures ménagères
IMPACT DES REJETS URBAINS ET INDUSTRIELS SUR L'EAU SUPERFICIELLE ET SOUTERRAINE DANS LA PLAINE D’ANNABA (ALGERIE) IMPACT OF URBAN AND INDUSTRIAL WASTES ON SUPERFICIAL AND GROUNDWATER IN THE PLAIN OF ANNABA (ALGERIA)
Les rejets urbains au niveau de l’oued Meboudja, un des affluents de la Seybouse posent l’épineuse question de leur impact surles eaux superficielles et souterraines de la plaine de d’Annaba. Dans cette recherche, plusieurs campagnes de prélèvement à pas mensuel des eaux superficielles de l’oued et les eaux souterraines sur deux points témoins dont un en pompage ont étéréalisées pendant le cycle hydrologique annuel. La comparaison entre la composition chimique des eaux de l’oued et celles deseaux souterraines captées montre qu’au niveau de l’oued, on observe l’existence de deux polluants : le phosphate etl’ammonium, par contre, au niveau de la nappe on observe seulement les ions phosphate qui ont pu se déplacer sous la mêmeforme chimique entre l’oued et les deux puits.La diminution de la concentration des phosphates entre l’oued et les captages est due à l’effet de la dilution des concentrationspar les eaux de la nappe, la précipitation des phosphates sous la forme des phosphates de calcium et enfin l’adsorption par lesargiles. En revanche l’absence de l’ammonium dans les captages est due au changement de la forme azotée en nitrate au coursdu trajet entre les deux milieux sous l’effet des conditions oxydantes. Urban wastes in wadi of Meboudja, a tributary of the Seybouse raise the difficult question of their impact on surface andgroundwater in conjunction with the plain of Annaba. In this research, several sampling campaigns at no monthly surfacewater of the river and groundwater on two witnesses in which a pump were conducted during the annual hydrological cycle.The comparison between the chemical composition of the river’s water and those of groundwater collected shows that, weobserve the existence of two pollutants: phosphate and ammonium, for against, at the water there is only the phosphate ionsthat have been moving in the same chemical form between the river and the two wells.The decrease in the concentration of phosphate between river and catchments is due to the dilution effect by the groundwaterlevels, the precipitation of phosphate in the form of calcium phosphate and finally by the clays adsorption. Nonetheless, theabsence of ammonium in the catchments is due to the change in the form of nitrate nitrogen during the journey between thetwo communities as a result of oxidizing conditions
Structure-Guided Mutagenesis Reveals the Catalytic Residue that Controls the Regiospecificity of C6-Indole Prenyltransferases
Indole is a significant structural moiety and functionalization of the C−H bond in indole-containing molecules expands their chemical space, and modifies their properties and/or activities. Indole prenyltransferases (IPTs) catalyze the direct regiospecific installation of prenyl moieties on indole-derived compounds. IPTs have shown relaxed substrate flexibility enabling them to be used as tools for indole functionalization. However, the mechanism by which certain IPTs target a specific carbon position is not fully understood. Herein, we use structure-guided site-directed mutagenesis, in vitro enzymatic reactions, kinetics and structural-elucidation of analogs to verify the key catalytic residues that control the regiospecificity of all characterized regiospecific C6 IPTs. The presented results also demonstrate that substitution of PriB_His312 to Tyr leads to the synthesis of analogs prenylated at different positions than C6. This work contributes to understanding of how certain IPTs can access a challenging position in indole-derived compounds
The Impact of Supporting Family Caregivers Before Bereavement on Outcomes After Bereavement: Adequacy of End-of-Life Support and Achievement of Preferred Place of Death
Abstract
Objectives
This study investigated the extent to which using the Carer Support Needs Assessment Tool (CSNAT) intervention during the caregiving period has affected bereaved family caregivers’ perceptions of adequacy of support, their grief and wellbeing and achievement of their preferred place of death.
Method
All family caregivers who participated in a stepped wedge cluster trial of the CSNAT intervention in Western Australia (2012-14) and completed the pre-bereavement study (n=322) were invited to take part in a caregiver survey by telephone 4-6 months post-bereavement (2015). The survey measured the adequacy of end of life support, the level of grief, the current physical and mental health, and the achievement of the preferred place of death.
Results
The response rate was 66% (152, intervention; 60 control). The intervention group perceived their pre-bereavement support needs had been adequately met to a significantly greater extent than the control group (d=0.43, p<0.001) and that patients have achieved their preferred place of death more often according to their caregivers (79.6% vs 63.6%, p=0.034). There was also a greater agreement on the preferred place of death between patients and their caregivers in the intervention group (p=0.02).
Conclusions
The results from this study provide evidence that the CSNAT intervention has a positive impact on perceived adequacy of support of bereaved family caregivers and achievement of preferred place of death according to caregivers. The benefits gained by caregivers in being engaged in early and direct assessment of their support needs pre-bereavement, reinforces the need for palliative care services to effectively support caregivers well before the patient’s death
Key features of palliative care service delivery to Indigenous peoples in Australia, New Zealand, Canada and the United States: A comprehensive review
Background: Indigenous peoples in developed countries have reduced life expectancies, particularly from chronic diseases. The lack of access to and take up of palliative care services of Indigenous peoples is an ongoing concern.
Objectives: To examine and learn from published studies on provision of culturally safe palliative care service delivery to Indigenous people in Australia, New Zealand (NZ), Canada and the United States of America (USA); and to compare Indigenous peoples’ preferences, needs, opportunities and barriers to palliative care.
Methods: A comprehensive search of multiple databases was undertaken. Articles were included if they were published in English from 2000 onwards and related to palliative care service delivery for Indigenous populations; papers could use quantitative or qualitative approaches. Common themes were identified using thematic synthesis. Studies were evaluated using Daly’s hierarchy of evidence-for-practice in qualitative research.
Results: Of 522 articles screened, 39 were eligible for inclusion. Despite diversity in Indigenous peoples’ experiences across countries, some commonalities were noted in the preferences for palliative care of Indigenous people: to die close to or at home; involvement of family; and the integration of cultural practices. Barriers identified included inaccessibility, affordability, lack of awareness of services, perceptions of palliative care, and inappropriate services. Identified models attempted to address these gaps by adopting the following strategies: community engagement and ownership; flexibility in approach; continuing education and training; a whole-of-service approach; and local partnerships among multiple agencies. Better engagement with Indigenous clients, an increase in number of palliative care patients, improved outcomes, and understanding about palliative care by patients and their families were identified as positive achievements.
Conclusions: The results provide a comprehensive overview of identified effective practices with regards to palliative care delivered to Indigenous populations to guide future program developments in this field. Further research is required to explore the palliative care needs and experiences of Indigenous people living in urban areas
Modeling and Simulation of PV Panel Under Different Internal and Environmental Conditions with Non-constant Load
This paper focuses on PV power conversion under different internal and environmental conditions with non-constant load, connected to a smart grid system. Due to environmental conditions, the PV system is a non-linear system and difficult to predict the power conversion. In the aspect of internal variables, it includes the five parameters of the single diode solar cell model identify their sensitivity through error function. It also identifies the relation between environmental conditions, mainly: irradiance, temperature and wind speed. The modeling and computational simulation with laboratory work identify the effects of internal and environmental effect on the system. The model gives details about the sensitivity of each environmental condition using error function. The work includes the decrease of energy conversion by the solar panel as a function of time due to the shadow effect that affects its performance. Besides these, a smart system is introduced as a DAQ system in laboratory environment to get in real time the power conversion value with the P-V and I-V characteristics of the PV panel
Low Mannose-Binding Lectin Concentration Is Associated with Severe Infection in Patients with Hematological Cancer Who Are Undergoing Chemotherapy
Background. Mannose-binding lectin (MBL) is a serum lectin involved in innate immune response. Low serum MBL concentration may constitute a risk factor for infection in patients receiving myelosuppressive chemotherapy. Methods. We conducted a prospective, observational study that assessed MBL concentration as a risk factor for infection in patients with hematological malignancy who were hospitalized to undergo at least 1 chemotherapy cycle. MBL deficiency was defined using an algorithm that considered the serum MBL concentration and the MBL genotype. The primary end point was the ratio of duration of febrile neutropenia to the duration of neutropenia. Secondary end points included the incidence of severe infection (e.g., sepsis, pneumonia, bacteremia, and invasive fungal infection). Logistic regression analysis was conducted, and Fisher's exact test was used to analyze binary outcomes, and Kaplan-Meier estimates and log rank tests were used for time-to-event variables. Results. We analyzed 255 patients who received 569 cycles of chemotherapy. The median duration of neutropenia per cycle was 7 days (interquartile range, 0-13 days). Sixty-two patients (24%) were found to have MBL deficiency. Febrile neutropenia occurred at least once in 200 patients. No difference in the primary outcome was seen. The incidence of severe infection was higher among MBL-deficient patients than among non-MBL-deficient patients (1.96 vs. 1.34 cases per 100 days for analysis of all patients [P = .008] and 1.85 vs. 0.94 cases per 100 days excluding patients with acute leukemia [P < .001]). Conclusions. MBL deficiency does not predispose adults with hematological cancer to more-frequent or more-prolonged febrile episodes during myelosuppressive chemotherapy, but MBL-deficient patients have a greater number of severe infections and experience their first severe infection earlier, compared with nondeficient patient
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