The OptimaMed intervention to reduce medication burden in nursing home residents with severe dementia: results from a pragmatic, controlled study.

BACKGROUND: Nursing home (NH) residents with severe dementia use many medications, sometimes inappropriately within a comfort care approach. Medications should be regularly reviewed and eventually deprescribed. This pragmatic, controlled trial assessed the effect of an interprofessional knowledge exchange (KE) intervention to decrease medication load and the use of medications of questionable benefit among these residents. METHODS: A 6-month intervention was performed in 4 NHs in the Quebec City area, while 3 NHs, with comparable admissions criteria, served as controls. Published lists of "mostly", "sometimes" or "exceptionally" appropriate medications, tailored for NH residents with severe dementia, were used. The intervention included 1) information for participants' families about medication use in severe dementia; 2) a 90-min KE session for NH nurses, pharmacists, and physicians; 3) medication reviews by NH pharmacists using the lists; 4) discussions on recommended changes with nurses and physicians. Participants' levels of agitation and pain were evaluated using validated scales at baseline and the end of follow-up. RESULTS: Seven (7) NHs and 123 participants were included for study. The mean number of regular medications per participant decreased from 7.1 to 6.6 in the intervention, and from 7.7 to 5.9 in the control NHs (p-value for the difference in differences test: < 0.05). Levels of agitation decreased by 8.3% in the intervention, and by 1.4% in the control NHs (p = 0.026); pain levels decreased by 12.6% in the intervention and increased by 7% in the control NHs (p = 0.049). Proportions of participants receiving regular medications deemed only exceptionally appropriate decreased from 19 to 17% (p = 0.43) in the intervention and from 28 to 21% (p = 0.007) in the control NHs (p = 0.22). The mean numbers of regular daily antipsychotics per participant fell from 0.64 to 0.58 in the intervention and from 0.39 to 0.30 in the control NHs (p = 0.27). CONCLUSIONS: This interprofessional intervention to reduce inappropriate medication use in NH residents with severe dementia decreased medication load in both intervention and control NHs, without important concomitant increase in agitation, but mixed effects on pain levels. Practice changes and heterogeneity within these 7 NHs, and a ceiling effect in medication optimization likely interfered with the intervention. TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov: # NCT05155748 (first registration 03-10-2017).

Using a SPATIAL INS/GNSS MEMS Unit to Detect Local Gravity Variations in Static and Mobile Experiments: First Results.

In this study, we present the feasibility of using gravity measurements made with a small inertial navigation system (INS) during in situ experiments, and also mounted on an unmanned aerial vehicle (UAV), to recover local gravity field variations. The INS operated is the SPATIAL one developed by Advanced Navigation, which has three-axis accelerometers. When the temperature bias is corrected, these types of INS are powerful enough to present the periodic signal corresponding to the solid Earth tides. There is also a clear correlation with the data measured at different altitudes by a CG5 gravimeter. However, these data were recorded on static points, so we also studied the INS in a moving platform on a UAV. Because there are a lot of vibrations recorded by the INS (wind, motor, on-board computer), the GPS and accelerometric data need to be filtered extensively. Once the data are corrected so they do not show thermal bias and low-pass filtered, we take the second derivative of the altitude (GPS) data to find the radial accelerometry of the drone and compare it to the radial accelerometry measured directly by the INS, in order to isolate the accelerometric signal that is related to the area that is being studied and the altitude. With a high enough precision, this method could be used to obtain the gravity variations due to the topography and density variations in the ground.

Job Satisfaction for Caregivers and Other Employees in Innovative Long-Term Care Homes for Residents With Cognitive Problems.

New housing models have emerged in Europe, Australia, the United States, and Canada. Intended for individuals with neurocognitive disorders, these models are characterized by a philosophy centered on the person, self-determination, liberty of choice, flexibility of care, acceptance of risk, and autonomy. Work and care are organized according to the pace and preferences of residents. The current multiple case study highlights the main sources of job satisfaction for caregivers and other employees in four innovative residential settings. Five themes are addressed as perceived by 58 employees: Work Motivation, Work Organization, Collaboration and Decision-Making Latitude, Quality of Work Life, and Continuing Education. These data will help inform clinical staff, policymakers, and the scientific community about clinical and organizational practices that contribute to job satisfaction in innovative residential settings. [Journal of Gerontological Nursing, 49(10), 36-43.].

Cell Fate: What's Evolution Got to Do With It?

Theoretical frameworks concerning cell fate typically center on proximate causes to explain how cells know what type they are meant to become. While major advances in cell fate theory have been achieved by these mechanism-focused frameworks, there are some aspects of cell decision-making that require an evolutionary interpretation. While mechanistic biologists sometimes turn to evolutionary theory to gain insights about cell fate (cancer is a good example), it is not entirely clear in cell fate theory what insights evolutionary theory can add, and why in some cases it is required for understanding cell fate. In this perspective we draw on our work on cellular mortality to illustrate how evolutionary theory provides an explanation for death being selected as one of the potential cell fates. Using our hypothesis for why some microbes in a community choose death as their fate, we suggest that some insights in cell fate theory are inaccessible to a theoretical framework that focuses solely on proximate causes.

The concepts and origins of cell mortality.

Organismal death is foundational to the evolution of life, and many biological concepts such as natural selection and life history strategy are so fashioned only because individuals are mortal. Organisms, irrespective of their organization, are composed of basic functional units-cells-and it is our understanding of cell death that lies at the heart of most general explanatory frameworks for organismal mortality. Cell death can be exogenous, arising from transmissible diseases, predation, or other misfortunes, but there are also endogenous forms of death that are sometimes the result of adaptive evolution. These endogenous forms of death-often labeled programmed cell death, PCD-originated in the earliest cells and are maintained across the tree of life. Here, we consider two problematic issues related to PCD (and cell mortality generally). First, we trace the original discoveries of cell death from the nineteenth century and place current conceptions of PCD in their historical context. Revisions of our understanding of PCD demand a reassessment of its origin. Our second aim is thus to structure the proposed origin explanations of PCD into coherent arguments. In our analysis we argue for the evolutionary concept of PCD and the viral defense-immunity hypothesis for the origin of PCD. We suggest that this framework offers a plausible account of PCD early in the history of life, and also provides an epistemic basis for the future development of a general evolutionary account of mortality.

The Ancient Origins of Death Domains Support the 'Original Sin' Hypothesis for the Evolution of Programmed Cell Death.

The discovery of caspase homologs in bacteria highlighted the relationship between programmed cell death (PCD) evolution and eukaryogenesis. However, the origin of PCD genes in prokaryotes themselves (bacteria and archaea) is poorly understood and a source of controversy. Whether archaea also contain C14 peptidase enzymes and other death domains is largely unknown because of a historical dearth of genomic data. Archaeal genomic databases have grown significantly in the last decade, which allowed us to perform a detailed comparative study of the evolutionary histories of PCD-related death domains in major archaeal phyla, including the deepest branching phyla of Candidatus Aenigmarchaeota, Candidatus Woesearchaeota, and Euryarchaeota. We identified death domains associated with executioners of PCD, like the caspase homologs of the C14 peptidase family, in 321 archaea sequences. Of these, 15.58% were metacaspase type I orthologues and 84.42% were orthocaspases. Maximum likelihood phylogenetic analyses revealed a scattered distribution of orthocaspases and metacaspases in deep-branching bacteria and archaea. The tree topology was incongruent with the prokaryote 16S phylogeny suggesting a common ancestry of PCD genes in prokaryotes and subsequent massive horizontal gene transfer coinciding with the divergence of archaea and bacteria. Previous arguments for the origin of PCD were philosophical in nature with two popular propositions being the "addiction" and 'original sin' hypotheses. Our data support the 'original sin' hypothesis, which argues for a pleiotropic origin of the PCD toolkit with pro-life and pro-death functions tracing back to the emergence of cellular life-the Last Universal Common Ancestor State.

Prioritization of indicators of the quality of care provided to older adults with frailty by key stakeholders from five canadian provinces.

BACKGROUND: To meet the needs of older adults with frailty better, it is essential to understand which aspects of care are important from their perspective. We therefore sought to assess the importance of a set of quality indicators (QI) for monitoring outcomes in this population. METHODS: In this mixed-method study, key stakeholders completed a survey on the importance of 36 QIs, and then explained their ratings in a semi-structured interview. Stakeholders included older adults with frailty and their caregivers, healthcare providers (HCPs), and healthcare administrators or policy/decision makers (DMs). We conducted descriptive statistical analyses of quantitative variables, and deductive thematic qualitative analyses of interview transcripts. RESULTS: The 42 participants (8 older adults, 18 HCPs, and 16 DMs) rated six QIs as more important: increasing the patients' quality of life; increasing healthcare staff skills; decreasing patients' symptoms; decreasing family caregiver burden; increasing patients' satisfaction with care; and increasing family doctor continuity of care. CONCLUSIONS: Key stakeholders prioritized QIs that focus on outcomes targeted to patients and caregivers, whereas the current healthcare systems generally focus on processes of care. Quality improvement initiatives should therefore take better account of aspects of care that are important for older adults with frailty, such as having a chance to express their individual goals of care, receiving quality communications from HCPs, or monitoring symptoms that they might not spontaneously describe. Our results point to the need for patient-centred care that is oriented toward quality of life for older adults with frailty.

Programmed cell death as a black queen in microbial communities.

Programmed cell death (PCD) in unicellular organisms is in some instances an altruistic trait. When the beneficiaries are clones or close kin, kin selection theory may be used to explain the evolution of the trait, and when the trait evolves in groups of distantly related individuals, group or multilevel selection theory is invoked. In mixed microbial communities, the benefits are also available to unrelated taxa. But the evolutionary ecology of PCD in communities is poorly understood. Few hypotheses have been offered concerning the community role of PCD despite its far-reaching effects. The hypothesis we consider here is that PCD is a black queen. The Black Queen Hypothesis (BQH) outlines how public goods arising from a leaky function are exploited by other taxa in the community. Black Queen (BQ) traits are essential for community survival, but only some members bear the cost of possessing them, while others lose the trait In addition, BQ traits have been defined in terms of adaptive gene loss, and it is unknown whether this has occurred for PCD. Our conclusion is that PCD fulfils the two most important criteria of a BQ (leakiness and costliness), but that more empirical data are needed for assessing the remaining two criteria. In addition, we hold that for viewing PCD as a BQ, the original BQH needs to include social traits. Thus, despite some empirical and conceptual shortcomings, the BQH provides a helpful avenue for investigating PCD in microbial communities.

The 4-Celled Tetrabaena socialis Nuclear Genome Reveals the Essential Components for Genetic Control of Cell Number at the Origin of Multicellularity in the Volvocine Lineage.

Multicellularity is the premier example of a major evolutionary transition in individuality and was a foundational event in the evolution of macroscopic biodiversity. The volvocine chlorophyte lineage is well suited for studying this process. Extant members span unicellular, simple colonial, and obligate multicellular taxa with germ-soma differentiation. Here, we report the nuclear genome sequence of one of the most morphologically simple organisms in this lineage-the 4-celled colonial Tetrabaena socialis and compare this to the three other complete volvocine nuclear genomes. Using conservative estimates of gene family expansions a minimal set of expanded gene families was identified that associate with the origin of multicellularity. These families are rich in genes related to developmental processes. A subset of these families is lineage specific, which suggests that at a genomic level the evolution of multicellularity also includes lineage-specific molecular developments. Multiple points of evidence associate modifications to the ubiquitin proteasomal pathway (UPP) with the beginning of coloniality. Genes undergoing positive or accelerating selection in the multicellular volvocines were found to be enriched in components of the UPP and gene families gained at the origin of multicellularity include components of the UPP. A defining feature of colonial/multicellular life cycles is the genetic control of cell number. The genomic data presented here, which includes diversification of cell cycle genes and modifications to the UPP, align the genetic components with the evolution of this trait.

OVLI-TA: An Unmanned Aerial System for Measuring Profiles and Turbulence in the Atmospheric Boundary Layer.

In recent years, we developed a small, unmanned aerial system (UAS) called OVLI-TA (Objet Volant Leger Instrumenté⁻Turbulence Atmosphérique) dedicated to atmospheric boundary layer research, in Toulouse (France). The device has a wingspan of 2.60 m and weighed 3.5 kg, including payload. It was essentially developed to investigate turbulence in a way complementary to other existing measurement systems, such as instrumented towers/masts. OVLI-TA's instrumental package includes a 5-hole probe on the nose of the airplane to measure attack and sideslip angles, a Pitot probe to measure static pressure, a fast inertial measurement unit, a GPS receiver, as well as temperature and moisture sensors in specific housings. In addition, the Pixhawk autopilot is used for autonomous flights. OVLI-TA is capable of profiling wind speed, wind direction, temperature, and humidity up to 1 km altitude, in addition to measuring turbulence. After wind tunnel calibrations, flight tests were conducted in March 2016 in Lannemezan (France), where there is a 60-m tower equipped with turbulence sensors. In July 2016, OVLI-TA participated in the international project DACCIWA (Dynamics-Aerosol-Chemistry-Clouds Interactions in West Africa), in Benin. Comparisons of the OVLI-TA observations with both the 60 m tower measurements and the radiosonde profiles showed good agreement for the mean values of wind, temperature, humidity, and turbulence parameters. Moreover, it validated the capacity of the drone to sample wind fluctuations up to a frequency of around 10 Hz, which corresponds to a spatial resolution of the order of 1 m.

Bio-Based Thermo-Reversible Aliphatic Polycarbonate Network.

Aliphatic polycarbonates represent an important class of materials with notable applications in the biomedical field. In this work, low Tg furan-functionalized bio-based aliphatic polycarbonates were cross-linked thanks to the Diels-Alder (DA) reaction with a bis-maleimide as the cross-linking agent. The thermo-reversible DA reaction allowed for the preparation of reversible cross-linked polycarbonate materials with tuneable properties as a function of the pendent furan content that was grafted on the polycarbonate backbone. The possibility to decrosslink the network around 70 °C could be an advantage for biomedical applications, despite the rather poor thermal stability of the furan-functionalized cross-linked polycarbonates.

Cell Death in Evolutionary Transitions in Individuality.

Programmed cell death (PCD) in cell groups and microbial communities affects population structures, nutrient recycling, and sociobiological interactions. A less explored area is the role played by PCD in the emergence of higher-level individuals. Here, we examine how cell death impacted evolutionary transitions in individuality (ETIs). The focus is on three specific ETIs - the emergence of the eukaryote cell, multicellularity, and social insects - and we review the theoretical and empirical evidence for the role of PCD in these three transitions. We find that PCD likely contributed to many of the processes involved in eukaryogenesis and the transition to multicellularity. PCD is important for the formation of cooperative groups and is a mechanism by which mutual dependencies between individuals evolve. PCD is also a conflict mediator and involved in division of labor in social groups and in the origin of new cell types. In multicellularity, PCD facilitates the transfer of fitness to the higher-level individual. In eusocial insects, PCD of the gonadal cells in workers is the basis for conflict mediation and the division of labor in the colony. In the three ETIs discussed here, PCD likely played an essential role, without which alternate mechanisms would have been necessary for these increases in complexity to occur.

Characterization of recombinant OspA in two different Borrelia vaccines with respect to immunological response and its relationship to functional parameters.

BACKGROUND: Prevention of Lyme disease in dogs in North America depends on effective vaccination against infection by the tick vector-born spirochete Borrelia burgdorferi. Most vaccines effectively prevent spirochete transmission to dogs during tick feeding based on immunization with the outer-surface lipoprotein A (OspA) of B. burgdorferi. More recently, vaccines containing additional OspC protein moieties have been introduced. These are designed to enhance protection by forming a second line of defense within the vertebrate host, where OspC expression replaces OspA as the dominant surface antigen. However, supportive data for demonstration of OspC mediated protection is still lacking. Since OspA immunogenicity is of paramount importance to protection against spirochete transmission; this study was designed to compare the immunogenicity of two commercially available vaccines against the Borrelia burgdorferi OspA. We further characterized OspA antigen fractions of these vaccines with respect to their biochemical and biophysical properties. RESULTS: Two groups of beagle dogs (n = 9) were administered either: (1) a nonadjuvanted/monovalent, recombinant OspA vaccine (Recombitek® Lyme) or (2) an adjuvanted, recombinant OspA /OspC chimeric fusion vaccine (Vanguard® crLyme). The onset of the anti-OspA antibody response elicited by the nonadjuvanted/monovalent OspA vaccine was significantly earlier than that for the bivalent OspA /OspC vaccine and serum borreliacidal activity was significantly greater at all post-vaccination time points. As expected, only dogs inoculated with the bivalent OspA/OspC vaccine mounted a humoral anti-OspC response. However, only three out of nine dogs in that group had a positive response. Comparison of the OspA vaccine structures revealed that the OspA in the nonadjuvanted/monovalent vaccine was primarily in the lipidated form, eluting (SEC-HPLC) at a high molecular weight, suggestive of micelle formation. Conversely, the OspA moiety of the OspA/OspC vaccine was found to be nonlipidated and eluted as the monomeric protein. CONCLUSIONS: We hypothesize that these structural differences may account for the superior immunogenicity of the nonadjuvanted monovalent recombinant OspA vaccine in dogs over the adjuvanted OspA fraction of the OspA/OspC vaccine.

Quasi-experimental evaluation of a multifaceted intervention to improve quality of end-of-life care and quality of dying for patients with advanced dementia in long-term care institutions.

BACKGROUND: Improvement in the quality of end-of-life care for advanced dementia is increasingly recognized as a priority in palliative care. AIM: To evaluate the impact of a multidimensional intervention to improve quality of care and quality of dying in advanced dementia in long-term care facilities. DESIGN: Quasi-experimental study with the intervention taking place in two long-term care facilities versus usual care in two others over a 1-year period. The intervention had five components: (1) training program to physicians and nursing staff, (2) clinical monitoring of pain using an observational pain scale, (3) implementation of a regular mouth care routine, (4) early and systematic communication with families about end-of-life care issues with provision of an information booklet, and (5) involvement of a nurse facilitator to implement and monitor the intervention. Quality of care was assessed with the Family Perception of Care Scale. The Symptom Management for End-of-Life Care in Dementia and the Comfort Assessment in Dying scales were used to assess the quality of dying. PARTICIPANTS: A total of 193 residents with advanced dementia and their close family members were included (97 in the intervention group and 96 in the usual care group). RESULTS: The Family Perception of Care score was significantly higher in the intervention group than in the usual care group (157.3 vs 149.1; p = 0.04). The Comfort Assessment and Symptom Management scores were also significantly higher in the intervention group. CONCLUSIONS: Our multidimensional intervention in long-term care facilities for patients with terminal dementia resulted in improved quality of care and quality of dying when compared to usual care.

Microbiota Quality and Mitochondrial Activity Link with Occurrence of Muscle Cramps in Hemodialysis Patients using Citrate Dialysate: A Pilot Study.

BACKGROUND/AIMS: Hemodialysis-associated muscle cramp (HAMC) is a common complication under citrate dialysate (CD) occurring in 30% of cases. Our objectives were to assess the gut microbiota quality, mitochondrial activity, and to investigate their possible relationship with HAMC. METHODS: Ten end-stage renal disease patients (78.9 ± 2.1 years) treated by hemodialysis (HD) with CD were enrolled and then classified according to the frequency of HAMCs: "frequent HAMCs group" (n = 5) and "absence of HAMCs group" (n = 5). Gut microbiota quality, mitochondrial activity, and some markers of oxidative stress (OS) were investigated. RESULTS: In patients with cramps, gut microbiota diversity seemed lower and some genera including Helicobacter, Lachnospira, Roseburia, and Haemophilus seemed over-expressed, a significant increase of citratemia and significant lowering mitochondrial function were observed. No difference was observed on the OS markers. CONCLUSION: This first clinical study revealed a possible dysbiosis of microbiota and a mitochondrial dysfunction into HD patients with cramps under CD compared to patients without cramp.

The OptimaMed intervention to reduce inappropriate medications in nursing home residents with severe dementia: results from a quasi-experimental feasibility pilot study.

BACKGROUND: Medication regimens in nursing home (NH) residents with severe dementia should be frequently reviewed to avoid inappropriate medication, overtreatment and adverse drug events, within a comfort care approach. This study aimed at testing the feasibility of an interdisciplinary knowledge exchange (KE) intervention using a medication review guidance tool categorizing medications as either "generally", "sometimes" or "exceptionally" appropriate for NH residents with severe dementia. METHODS: A quasi-experimental feasibility pilot study with 44 participating residents aged 65 years or over with severe dementia was carried out in three NH in Quebec City, Canada. The intervention comprised an information leaflet for residents' families, a 90-min KE session for NH general practitioners (GP), pharmacists and nurses focusing on the medication review guidance tool, a medication review by the pharmacists for participating residents with ensuing team discussion on medication changes, and a post-intervention KE session to obtain feedback from team staff. Medication regimens and levels of pain and of agitation of the participants were evaluated at baseline and at 4 months post-intervention. A questionnaire for team staff explored perceived barriers and facilitators. Statistical differences in measures comparing pre and post-intervention were assessed using paired t-tests and Cochran's-Q tests. RESULTS: The KE sessions reached 34 NH team staff (5 GP, 4 pharmacists, 6 heads of care unit and 19 staff nurses). Forty-four residents participated in the study and were followed for a mean of 104 days. The total number of regular medications was 372 pre and 327 post-intervention. The mean number of regular medications per resident was 7.86 pre and 6.81 post-intervention. The odds ratios estimating the risks of using any regular medication or a "sometimes appropriate" medication post-intervention were 0.81 (95% CI: 0.71-0.92) and 0.83 (95% CI: 0.74-0.94), respectively. CONCLUSION: A simple KE intervention using a medication review guidance tool categorizing medications as being either "generally", "sometimes" or "exceptionally" appropriate in severe dementia was well received and accompanied by an overall reduction in medication use by NH residents with severe dementia. Levels of agitation were unaffected and there was no clinically significant changes in levels of pain. Staff feedback provided opportunities to improve the intervention.

Key stakeholders' views on the quality of care and services available to frail seniors in Canada.

BACKGROUND: Frail seniors often receive ineffective care, which does not meet their needs. It is still unclear how healthcare systems should be redesigned to be more sensitive to the needs and values of frail seniors and their caregivers. We thus aimed to describe key stakeholders' perspectives on the current healthcare and services available to frail seniors. METHODS: In this qualitative descriptive study, we conducted semi-structured interviews with a convenience sample of 42 frail seniors, caregivers, clinicians, or healthcare administrators/decision makers involved in frail senior care from five Canadian provinces. We explored participants' perspectives on the quality of care and services for frail seniors. We used an inductive/deductive thematic data analysis approach based on the Square-of-Care model, including emerging themes using the constant comparison method. RESULTS: We grouped participants' perspectives into strengths, weaknesses and opportunities for improvement, and then into nine themes: care processes, continuity of care, social frailty, access to healthcare and services, models of healthcare delivery, cost of care, healthcare staff management and professional development of healthcare providers, material resources and environmental design of healthcare facilities, and coordination of care. Our findings suggest redesigning assessment, communication with frail seniors and their caregivers, targeting care and services to the needs, and integrating care better across settings and in time. CONCLUSIONS: A systematic identification of frail older people is the first step to adapt healthcare systems to this population's needs. Participation of frail older people and their caregivers to decision making would also allow choosing care plans meeting their care goals. The integration of care and services across settings, over time, and with various providers, is also needed to meet frail senior needs.

Evolution of cytokinesis-related protein localization during the emergence of multicellularity in volvocine green algae.

BACKGROUND: The volvocine lineage, containing unicellular Chlamydomonas reinhardtii and differentiated multicellular Volvox carteri, is a powerful model for comparative studies aiming at understanding emergence of multicellularity. Tetrabaena socialis is the simplest multicellular volvocine alga and belongs to the family Tetrabaenaceae that is sister to more complex multicellular volvocine families, Goniaceae and Volvocaceae. Thus, T. socialis is a key species to elucidate the initial steps in the evolution of multicellularity. In the asexual life cycle of C. reinhardtii and multicellular volvocine species, reproductive cells form daughter cells/colonies by multiple fission. In embryogenesis of the multicellular species, daughter protoplasts are connected to one another by cytoplasmic bridges formed by incomplete cytokinesis during multiple fission. These bridges are important for arranging the daughter protoplasts in appropriate positions such that species-specific integrated multicellular individuals are shaped. Detailed comparative studies of cytokinesis between unicellular and simple multicellular volvocine species will help to elucidate the emergence of multicellularity from the unicellular ancestor. However, the cytokinesis-related genes between closely related unicellular and multicellular species have not been subjected to a comparative analysis. RESULTS: Here we focused on dynamin-related protein 1 (DRP1), which is known for its role in cytokinesis in land plants. Immunofluorescence microscopy using an antibody against T. socialis DRP1 revealed that volvocine DRP1 was localized to division planes during cytokinesis in unicellular C. reinhardtii and two simple multicellular volvocine species T. socialis and Gonium pectorale. DRP1 signals were mainly observed in the newly formed division planes of unicellular C. reinhardtii during multiple fission, whereas in multicellular T. socialis and G. pectorale, DRP1 signals were observed in all division planes during embryogenesis. CONCLUSIONS: These results indicate that the molecular mechanisms of cytokinesis may be different in unicellular and multicellular volvocine algae. The localization of DRP1 during multiple fission might have been modified in the common ancestor of multicellular volvocine algae. This modification may have been essential for the re-orientation of cells and shaping colonies during the emergence of multicellularity in this lineage.

[A typology of mental health comorbidity in workplaces: results from the SALVEO study]. / Une typologie de la comorbidité en santé mentale au travail : résultats de l'étude SALVEO.

Objectives The aim of this study consists in describing the nature of mental health comorbidity among workers. Precisely, we seek to examine the presence of concomitant associations between burnout (cynicism, emotional exhaustion, professionnal inefficacy) and psychoactive substance use (heavy episodic drinking, above low-risk drinking guidelines, and psychotropic drug use).Methods The SALVEO study is based on a cross-sectional sample of 1966 workers from the province of Québec, Canada. Latent class analyses were performed in order to identify typical patterns corresponding to distinct forms of mental health comorbidity in the data. Multinomial logistic regressions on latent classes were performed using covariables pertaining to work and non-work domains and workers' individual characteristics.Results Four typical patterns in mental health comorbidity were found: 1- "Severe burnout and psychotropic drug use"; 2- "At risk drinking and cynicism"; 3- "Emotional exhaustion and professional inefficacy"; and 4- "Relatively healthy state". Of all four patterns, the "Severe burnout and psychotropic drug use" pattern presented the highest number of cumulative risks (environmental and individual).Conclusion Comorbidity in mental health is a matter of importance in workplaces from the province of Québec. The severity in the different patterns of mental health comorbidity expressed a cumulative effect of risk factors from the work and non-work domains, as well as individual characteristics.

Robust sequence alignment using evolutionary rates coupled with an amino acid substitution matrix.

BACKGROUND: Selective pressures at the DNA level shape genes into profiles consisting of patterns of rapidly evolving sites and sites withstanding change. These profiles remain detectable even when protein sequences become extensively diverged. A common task in molecular biology is to infer functional, structural or evolutionary relationships by querying a database using an algorithm. However, problems arise when sequence similarity is low. This study presents an algorithm that uses the evolutionary rate at codon sites, the dN/dS (ω) parameter, coupled to a substitution matrix as an alignment metric for detecting distantly related proteins. The algorithm, called BLOSUM-FIRE couples a newer and improved version of the original FIRE (Functional Inference using Rates of Evolution) algorithm with an amino acid substitution matrix in a dynamic scoring function. The enigmatic hepatitis B virus X protein was used as a test case for BLOSUM-FIRE and its associated database EvoDB. RESULTS: The evolutionary rate based approach was coupled with a conventional BLOSUM substitution matrix. The two approaches are combined in a dynamic scoring function, which uses the selective pressure to score aligned residues. The dynamic scoring function is based on a coupled additive approach that scores aligned sites based on the level of conservation inferred from the ω values. Evaluation of the accuracy of this new implementation, BLOSUM-FIRE, using MAFFT alignment as reference alignments has shown that it is more accurate than its predecessor FIRE. Comparison of the alignment quality with widely used algorithms (MUSCLE, T-COFFEE, and CLUSTAL Omega) revealed that the BLOSUM-FIRE algorithm performs as well as conventional algorithms. Its main strength lies in that it provides greater potential for aligning divergent sequences and addresses the problem of low specificity inherent in the original FIRE algorithm. The utility of this algorithm is demonstrated using the Hepatitis B virus X (HBx) protein, a protein of unknown function, as a test case. CONCLUSION: This study describes the utility of an evolutionary rate based approach coupled to the BLOSUM62 amino acid substitution matrix in inferring protein domain function. We demonstrate that such an approach is robust and performs as well as an array of conventional algorithms.