Modeling, Simulating, and Parameter Fitting of Biochemical Kinetic Experiments

In many chemical and biological applications, systems of differential equations containing unknown parameters are used to explain empirical observations and experimental data. The DEs are typically nonlinear and difficult to analyze, requiring numerical methods to approximate the solutions. Compounding this difficulty are the unknown parameters in the DE system, which must be given specific numerical values in order for simulations to be run. Estrogen receptor protein dimerization is used as an example to demonstrate model construction, reduction, simulation, and parameter estimation. Mathematical, computational, and statistical methods are applied to empirical data to deduce kinetic parameter estimates and guide decisions regarding future experiments and modeling. The process demonstrated serves as a pedagogical example of quantitative methods being used to extract parameter values from biochemical data models.Comment: 23 pages, 9 figures, to be published in SIAM Revie

Expansions des innovations par retrait : éléments de caractérisation et de réflexion

L'étude sociologique des innovations propose des modèles génériques d'analyse rendant compte de la façon dont les inventions voient le jour et s'inscrivent dans la société. Le modèle diffusionniste, par exemple, rend compte des mécanismes de diffusion des nouveautés au sein d'une population d'adoptants (Rogers, 1962). Le modèle de la traduction (Akrich, Callon et al., 1988), de son côté, invite à décrire les déplacements et transformations qui permettent aux réseaux sociotechniques de s'étendre ; il s'agit alors de considérer les innovations comme des réagencements de relations entre entités de toutes sortes (acteurs, objets, institutions, normes), redéfinies chemin faisant. Ces transformations, et notamment le sens que les acteurs sociaux leur confèrent, constituent des supports privilégiés d'observation des mutations des sociétés (Vinck 2012). Elles fournissent ainsi des informations anthropologiques précieuses sur les façons dont ces sociétés se transforment et pensent ces transformations ou leur conduite. Parmi les multiples formes de processus d'innovation qui affectent les technologies, les marchés, l'alimentation, l'environnement et les relations à autrui, certaines sont associées non pas à l'introduction d'une nouveauté mais au retrait ou à la suppression d'un élément préexistant. Ce retrait est au coeur d'une série de transformations. Elles sont utiles à comprendre pour l'analyse des innovations elles-mêmes, mais aussi pour ce qu'elles donnent à voir des trajectoires de changement de nos sociétés. Dans cet article, nous discuterons de quelques propriétés de certaines innovations que avons qualifiées d'innovations par retrait (Goulet & Vinck, 2012). Nous examinerons leurs formes, ainsi que les logiques ou valeurs animant les acteurs qui les portent. Nous mettrons au jour quelques pistes de réflexion liées à cette manière de penser l'innovation autrement que comme l'insertion d'une nouveauté au sein de la société

A inovação por sustração : contribução para a sociología do distanciamento

To develop the understanding of innovation processes conceptualized in terms of association through the "sociology of translation" (cf. actor-network theory) studies, this article analyses innovation processes in terms of dissociation and detachment mechanisms, examining innovation through "withdrawal"; that is, innovation based on reducing or withdrawing use of a practice - "subtracting", "detaching" - a given artefact. Specifically, it focuses on the shift to farming techniques that have eliminated ploughing, bringing to light four major mechanisms constitutive of dissociation : centrifugal association ; making entities and associations visible ; making other entities and associations invisible; bringing together or " associating " new entities. The study helps refine our understanding of the detachment processes at work in innovation

Notes on Cynipid Galls, Ground Beetles and Ground-dwelling Spiders Collected at Fort Severn, Ontario

A brief collecting trip to Fort Severn, Ontario (55°59' N, 87°38' W), in May 2001 revealed galls of three species of cynipid wasps (Hymenoptera: Cynipidae) on the wild rose Rosa acicularis. Roses and cynipid galls occur along the banks of the Severn River above the tree line because of clay deposits, heat, and rafts of vegetation carried north by the river. Ground beetles and spiders were collected with pitfall traps. Our identification of 15 species of ground beetles (Coleoptera: Carabidae), two of them new records for Ontario, and 11 species of ground spiders (Araneae: Lycosidae), all new records for northwestern Ontario, indicates that the invertebrate fauna in the area has been poorly studied. Roads and trails away from Fort Severn, regularly scheduled airline service, and convenient accommodations make the area ideal for biological studies.Une brève sortie de prélèvement à Fort Severn, en Ontario (55° 59' de lat. N., 87° 38' de long. O.), effectuée en mai 2001 a révélé l'existence de galles de trois espèces de cynips du rosier (hyménoptères: cynipidés) sur le rosier aciculaire Rosa acicularis. On trouve ce dernier et les galles du rosier le long des rives de la Severn au-dessus de la limite forestière en raison des dépôts d'argile, de la chaleur et de la végétation flottante que transporte la rivière en direction du Nord. On a prélevé des carabes et des araignées terricoles à l'aide de pièges à fosse. Notre identification de 15 espèces de carabes (coléoptères: carabidés), dont deux représentaient deux nouvelles espèces pour l'Ontario, et de 11 espèces d'araignées terricoles (aranéides: lycosidés), dont toutes étaient nouvelles pour le nord-ouest de l'Ontario, révèle que la faune invertébrée de la région n'a pas encore fait l'objet d'une étude approfondie. Les routes et les pistes menant à l'extérieur de Fort Severn, le service régulier de transport aérien et l'hébergement à proximité font de la région un emplacement idéal pour des études biologiques

Association between frailty and delirium in older adult patients discharged from hospital.

BACKGROUND: Delirium and frailty - both potentially reversible geriatric syndromes - are seldom studied together, although they often occur jointly in older patients discharged from hospitals. This study aimed to explore the relationship between delirium and frailty in older adults discharged from hospitals. METHODS: Of the 221 patients aged >65 years, who were invited to participate, only 114 gave their consent to participate in this study. Delirium was assessed using the confusion assessment method, in which patients were classified dichotomously as delirious or nondelirious according to its algorithm. Frailty was assessed using the Edmonton Frailty Scale, which classifies patients dichotomously as frail or nonfrail. In addition to the sociodemographic characteristics, covariates such as scores from the Mini-Mental State Examination, Instrumental Activities of Daily Living scale, and Cumulative Illness Rating Scale for Geriatrics and details regarding polymedication were collected. A multidimensional linear regression model was used for analysis. RESULTS: Almost 20% of participants had delirium (n=22), and 76.3% were classified as frail (n=87); 31.5% of the variance in the delirium score was explained by frailty (R (2)=0.315). Age; polymedication; scores of the Confusion Assessment Method (CAM), instrumental activities of daily living, and Cumulative Illness Rating Scale for Geriatrics; and frailty increased the predictability of the variance of delirium by 32% to 64% (R (2)=0.64). CONCLUSION: Frailty is strongly related to delirium in older patients after discharge from the hospital

Nursing intervention versus usual care to improve delirium among home-dwelling older adults receiving homecare after hospitalization: feasibility and acceptability of a Randomized Controlled Trail.

BACKGROUND: Delirium is an acute cognitive impairment among older hospitalized patients. It can persist until discharge and for months after that. Despite proof that evidence-based nursing interventions are effective in preventing delirium in acute hospitals, interventions among home-dwelling older patients is lacking. The aim was to assess feasibility and acceptability of a nursing intervention designed to detect and reduce delirium in older adults after discharge from hospital. METHODS: Randomized clinical pilot trial with a before/after design was used. One hundred and three older adults were recruited in a home healthcare service in French-speaking Switzerland and randomized into an experimental group (EG, n = 51) and a control group (CG, n = 52). The CG received usual homecare. The EG received usual homecare plus five additional nursing interventions at 48 and 72 h and at 7, 14 and 21 days after discharge. These interventions were tailored for detecting and reducing delirium and were conducted by a geriatric clinical nurse (GCN). All patients were monitored at the start of the study (M1) and throughout the month for symptoms of delirium (M2). This was documented in patients' records after usual homecare using the Confusion Assessment Method (CAM). At one month (M2), symptoms of delirium were measured using the CAM, cognitive status was measured using the Mini-Mental State Examination (MMSE), and functional status was measured using Katz and Lawton Index of activities of daily living (ADL/IADL). At the end of the study, participants in the EG and homecare nurses were interviewed about the acceptability of the nursing interventions and the study itself. RESULTS: Feasibility and acceptability indicators reported excellent results. Recruitment, retention, randomization, and other procedures were efficient, although some potentially issues were identified. Participants and nurses considered organizational procedures, data collection, intervention content, the dose-effect of the interventions, and methodology all to be feasible. Duration, patient adherence and fidelity were judged acceptable. Nurses, participants and informal caregivers were satisfied with the relevance and safety of the interventions. CONCLUSIONS: Nursing interventions to detect/improve delirium at home are feasible and acceptable. These results confirm that developing a large-scale randomized controlled trial would be appropriate. TRIAL REGESTRATION: ISRCTN registry no: 16103589 - 19 February 2016

Effect Estimation of an Innovative Nursing Intervention to Improve Delirium among Home-Dwelling Older Adults: A Randomized Controlled Pilot Trial.

AIMS: Estimating the effect of a nursing intervention in home-dwelling older adults on the occurrence and course of delirium and concomitant cognitive and functional impairment. METHODS: A randomized clinical pilot trial using a before/after design was conducted with older patients discharged from hospital who had a medical prescription to receive home care. A total of 51 patients were randomized into the experimental group (EG) and 52 patients into the control group (CG). Besides usual home care, nursing interventions were offered by a geriatric nurse specialist to the EG at 48 h, 72 h, 7 days, 14 days, and 21 days after discharge. All patients were monitored for symptoms of delirium using the Confusion Assessment Method. Cognitive and functional statuses were measured with the Mini-Mental State Examination and the Katz and Lawton Index. RESULTS: No statistical differences with regard to symptoms of delirium (p = 0.085), cognitive impairment (p = 0.151), and functional status (p = 0.235) were found between the EG and CG at study entry and at 1 month. After adjustment, statistical differences were found in favor of the EG for symptoms of delirium (p = 0.046), cognitive impairment (p = 0.015), and functional status (p = 0.033). CONCLUSION: Nursing interventions to detect delirium at home are feasible and accepted. The nursing interventions produced a promising effect to improve delirium