The arbuscular mycorrhizal fungus Glomus intraradices is haploid and has a small genome size in the lower limit of eukaryotes.

The genome size, complexity, and ploidy of the arbuscular mycorrhizal fungus (AMF) Glomus intraradices was determined using flow cytometry, reassociation kinetics, and genomic reconstruction. Nuclei of G. intraradices from in vitro culture, were analyzed by flow cytometry. The estimated average length of DNA per nucleus was 14.07+/-3.52 Mb. Reassociation kinetics on G. intraradices DNA indicated a haploid genome size of approximately 16.54 Mb, comprising 88.36% single copy DNA, 1.59% repetitive DNA, and 10.05% fold-back DNA. To determine ploidy, the DNA content per nucleus measured by flow cytometry was compared with the genome estimate of reassociation kinetics. G. intraradices was found to have a DNA index (DNA per nucleus per haploid genome size) of approximately 0.9, indicating that it is haploid. Genomic DNA of G. intraradices was also analyzed by genomic reconstruction using four genes (Malate synthase, RecA, Rad32, and Hsp88). Because we used flow cytometry and reassociation kinetics to reveal the genome size of G. intraradices and show that it is haploid, then a similar value for genome size should be found when using genomic reconstruction as long as the genes studied are single copy. The average genome size estimate was 15.74+/-1.69 Mb indicating that these four genes are single copy per haploid genome and per nucleus of G. intraradices. Our results show that the genome size of G. intraradices is much smaller than estimates of other AMF and that the unusually high within-spore genetic variation that is seen in this fungus cannot be due to high ploidy.

Kinematics and dynamic complexity of postural transitions in frail elderly subjects.

The aim of this study was to propose a methodology allowing a detailed characterization of body sit-to-stand/stand-to-sit postural transition. Parameters characterizing the kinematics of the trunk movement during sit-to-stand (Si-St) postural transition were calculated using one initial sensor system fixed on the trunk and a data logger. Dynamic complexity of these postural transitions was estimated by fractal dimension of acceleration-angular velocity plot. We concluded that this method provides a simple and accurate tool for monitoring frail elderly and to objectively evaluate the efficacy of a rehabilitation program.

The average inter-crossing number of equilateral random walks and polygons

In this paper, we study the average inter-crossing number between two random walks and two random polygons in the three-dimensional space. The random walks and polygons in this paper are the so-called equilateral random walks and polygons in which each segment of the walk or polygon is of unit length. We show that the mean average inter-crossing number ICN between two equilateral random walks of the same length n is approximately linear in terms of n and we were able to determine the prefactor of the linear term, which is a = (3 In 2)/(8) approximate to 0.2599. In the case of two random polygons of length n, the mean average inter-crossing number ICN is also linear, but the prefactor of the linear term is different from that of the random walks. These approximations apply when the starting points of the random walks and polygons are of a distance p apart and p is small compared to n. We propose a fitting model that would capture the theoretical asymptotic behaviour of the mean average ICN for large values of p. Our simulation result shows that the model in fact works very well for the entire range of p. We also study the mean ICN between two equilateral random walks and polygons of different lengths. An interesting result is that even if one random walk (polygon) has a fixed length, the mean average ICN between the two random walks (polygons) would still approach infinity if the length of the other random walk (polygon) approached infinity. The data provided by our simulations match our theoretical predictions very well.

Between-year variation in population sex ratio increases with complexity of the breeding system in Hymenoptera.

While adaptive adjustment of sex ratio in the function of colony kin structure and food availability commonly occurs in social Hymenoptera, long-term studies have revealed substantial unexplained between-year variation in sex ratio at the population level. In order to identify factors that contribute to increased between-year variation in population sex ratio, we conducted a comparative analysis across 47 Hymenoptera species differing in their breeding system. We found that between-year variation in population sex ratio steadily increased as one moved from solitary species, to primitively eusocial species, to single-queen eusocial species, to multiple-queen eusocial species. Specifically, between-year variation in population sex ratio was low (6.6% of total possible variation) in solitary species, which is consistent with the view that in solitary species, sex ratio can vary only in response to fluctuations in ecological factors such as food availability. In contrast, we found significantly higher (19.5%) between-year variation in population sex ratio in multiple-queen eusocial species, which supports the view that in these species, sex ratio can also fluctuate in response to temporal changes in social factors such as queen number and queen-worker control over sex ratio, as well as factors influencing caste determination. The simultaneous adjustment of sex ratio in response to temporal fluctuations in ecological and social factors seems to preclude the existence of a single sex ratio optimum. The absence of such an optimum may reflect an additional cost associated with the evolution of complex breeding systems in Hymenoptera societies.

Complexité, médecine générale et réformes des systèmes de santé [Complexity, general practice and reforms of health systems].

The family doctor facing complexity must decide in situations of low certainty and low agreement. Complexity is in part subjective but can also be measured. Changes in the health systems aim to reduce health costs. They tend to give priority to simple situations and to neglect complexity. One role of an academic institute of family medicine is to present and promote the results of scientific research supporting the principles of family medicine, taking into account both the local context and health systems reforms. In Switzerland the new challenge is the introduction of managed care.

Extended bottom-up proteomics with secreted aspartic protease Sap9.

We investigate the benefits and experimental feasibility of approaches enabling the shift from short (1.7kDa on average) peptides in bottom-up proteomics to about twice longer (~3.2kDa on average) peptides in the so-called extended bottom-up proteomics. Candida albicans secreted aspartic protease Sap9 has been selected for evaluation as an extended bottom-up proteomic-grade enzyme due to its suggested dibasic cleavage specificity and ease of production. We report the extensive characterization of Sap9 specificity and selectivity revealing that protein cleavage by Sap9 most often occurs in the vicinity of proximal basic amino acids, and in select cases also at basic and hydrophobic residues. Sap9 is found to cleave a large variety of proteins in a relatively short, ~1h, period of time and it is efficient in a broad pH range, including slightly acidic, e. g., pH5.5, conditions. Importantly, the resulting peptide mixtures contain representative peptides primarily in the target 3-7kDa range. The utility and advantages of this enzyme in routine analysis of protein mixtures are demonstrated and the limitations are discussed. Overall, Sap9 has a potential to become an enzyme of choice in an extended bottom-up proteomics, which is technically ready to complement the traditional bottom-up proteomics for improved targeted protein structural analysis and expanded proteome coverage. BIOLOGICAL SIGNIFICANCE: Advances in biological applications of mass spectrometry-based bottom-up proteomics are oftentimes limited by the extreme complexity of biological samples, e.g., proteomes or protein complexes. One of the reasons for it is in the complexity of the mixtures of enzymatically (most often using trypsin) produced short (<3kDa) peptides, which may exceed the analytical capabilities of liquid chromatography and mass spectrometry. Information on localization of protein modifications may also be affected by the small size of typically produced peptides. On the other hand, advances in high-resolution mass spectrometry and liquid chromatography have created an intriguing opportunity of improving proteome analysis by gradually increasing the size of enzymatically-derived peptides in MS-based bottom-up proteomics. Bioinformatics has already confirmed the envisioned advantages of such approach. The remaining bottle-neck is an enzyme that could produce longer peptides. Here, we report on the characterization of a possible candidate enzyme, Sap9, which may be considered for producing longer, e.g., 3-7kDa, peptides and lead to a development of extended bottom-up proteomics.

Taking care of the most vulnerable : a descriptive study of patients with 12 attendances or more at a Swiss university hospital emergency department in 2009

Introduction: Patients who repeatedly attend the Emergency Department (ED) often have a distinct and complex vulnerability profile that includes poor somatic, psychological, and social indicators. This profile has an impact on the patients' well-being as well as on hospital costs. The objective of the study was to specify the characteristics of hyper users (HU) and explore the connection with ED care and hospital costs. Methods: The study sample comprised all adult patients with 12 or more attendances at the ED of the Lausanne University Hospital in 2009. The data were collected by retrospectively searching internal databases to identify the patients concerned and then analysing the profiles of these patients. Information gathered included demographic, somatic, psychological, at-risk behaviour, and social indicators, and health system consumption including costs. Results: In 2009, 23 patients (0.1%) attended 12 times or more (425 attendances, 0.8%). The average age was about 43 years, 60.9% were female, and 47.8% single. Of these 95.7% had basic insurance, 87.0% had a general practitioner, and 30.4% were under legal guardianship. The majority attended in the evening or at night (67.1%), and almost one quarter of these attendances resulted in inpatient treatment (24.0%). Most HU had attended the ED in previous years too (95.7% in 2008). The most prevalent diagnoses concerned 'mental disorders' (87.0%). About 30.4% of patients had attempted suicide (all were female patients). Other frequent diagnoses concerned 'trauma' (65.2%), and the 'digestive' and the 'nervous system' (each 56.5%). At-risk behaviour such as severe alcohol consumption (34.8%), or excessive use of medicines (26.1%) was very frequent, and some patients used illicit drugs (21.7%). There was only a weak association between the number of ED attendances and the resulting costs. However, a reduction of one outpatient visit per patient would have decreased ED outpatient costs by 8.5%. Conclusions: HU often have a particularly vulnerable profile. Mental problems are prevalent among them, as are at-risk behaviour and severe somatic conditions. The complexity of the patients' profiles demands specific care that cannot be guaranteed within an everyday ED routine. The use of an interdisciplinary case management team might be a promising approach in diminishing the number of attendances and the associated costs, although the profiles of HU are such that they probably cannot completely give up ED attendance.

What kind of relationships between the evolution of pain, beliefs and bio-psycho-social complexity after a locomotor traumatism?

Introduction: Pain and beliefs have an influence on the patient's course in rehabilitation, pain causes fears and fears influence pain perception. The aim of this study is to understand pain and beliefs evolutions during rehabilitation taking into account of bio-psycho-social complexity.Patients and methods: 631 consecutive patients admitted in rehabilitation after a musculoskeletal traumatism were included and assessed at admission and at discharge. Pain was measured by VAS (Visual Analogical Scale), bio-psycho-social complexity by Intermed scale, and beliefs by judgement on Lickert scales. Four kinds of beliefs were evaluated: fear of a severe origin of pain, fear of movement, fear of pain and feeling of distress (loss of control). The association between the changes in pain and beliefs during the hospitalization was assessed by linear regressions.Results: After adjustment for gender, age, education and native language, patients with a decrease in pain during rehabilitation have higher probability of decreasing their fears. For the distress feeling, this relationship is weaker among bio-psycho-socially complex patients (odds-ratio 1.22 for each decreasing of 10mm/100 VAS) than among non-complex patients (OR 1.47). Patients with a pain decrease of 30% or more during hospitalization have higher probability of seeing their fears decrease, this relationship being stronger in complex patient for fear of a severe origin of pain.Discussion: The relationships between evolution of pain and beliefs move in the same direction. The higher a patient feels pain, the less they could be able to modify their dysfunctional beliefs. When the pain diminishes of 30% or more, the probability to challenge the beliefs is increased. The prognostic with regard to feeling of distress and fear of a severe origin of pain, is worse among bio-psycho-socially complex patients.

Prediction of myocardial infarction size using the SYNTAX score in patients treated with primary percutaneous coronary intervention for acute ST- segment elevation myocardial infarction

Objectives The relevance of the SYNTAX score for the particular case of patients with acute ST- segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI)  has previously only been studied in the setting of post hoc analysis of large prospective randomized clinical trials. A "real-life" population approach has never been explored before. The aim of this study was to evaluate the impact of the SYNTAX score for the prediction of the myocardial infarction size, estimated by the creatin-kinase (CK) peak value, using the SYNTAX score in patients treated with primary coronary intervention for acute ST-segment elevation myocardial infarction. Methods The primary endpoint of the study was myocardial infarction size as measured by the CK peak value. The SYNTAX score was calculated retrospectively in 253 consecutive patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) in a large tertiary referral center in Switzerland, between January 2009 and June 2010. Linear regression analysis was performed to compare myocardial infarction size with the SYNTAX score. This same endpoint was then stratified according to SYNTAX score tertiles: low <22 (n=178), intermediate [22-32] (n=60), and high >=33 (n=15). Results There were no significant differences in terms of clinical characteristics between the three groups. When stratified according to the SYNTAX score tertiles, average CK peak values of 1985 (low<22), 3336 (intermediate [22-32]) and 3684 (high>=33) were obtained with a p-value <0.0001. Bartlett's test for equal variances between the three groups was 9.999 (p-value <0.0067). A moderate Pearson product-moment correlation coefficient (r=0.4074) with a high statistical significance level (p-value <0.0001) was found. The coefficient of determination (R^2=0.1660) showed that approximately 17% of the variation of CK peak value (myocardial infarction size) could be explained by the SYNTAX score, i.e. by the coronary disease complexity. Conclusion In an all-comers population, the SYNTAX score is an additional tool in predicting myocardial infarction size in patients treated with primary percutaneous coronary intervention (PPCI). The stratification of patients in different risk groups according to SYNTAX enables to identify a high-risk population that may warrant particular patient care.

Impact of biocontrol strain Pseudomonas fluorescens CHA0 on rhizosphere bacteria isolated from barley (Hordeum vulgare L.) with special reference to Cytophaga-like bacteria.

AIMS: To assess the impact of the biocontrol strain Pseudomonas fluorescens CHA0 on a collection of barley rhizosphere bacteria using an agar plate inhibition assay and a plant microcosm, focusing on a CHA0-sensitive member of the Cytophaga-like bacteria (CLB). METHODS AND RESULTS: The effect of strain CHA0 on a collection of barley rhizosphere bacteria, in particular CLB and fluorescent pseudomonads sampled during a growth season, was assessed by a growth inhibition assay. On average, 85% of the bacteria were sensitive in the May sample, while the effect was reduced to around 68% in the July and August samples. In the May sample, around 95% of the CLB and around 45% of the fluorescent pseudomonads were sensitive to strain CHA0. The proportion of CHA0-sensitive CLB and fluorescent pseudomonad isolates decreased during the plant growth season, i.e. in the July and August samples. A particularly sensitive CLB isolate, CLB23, was selected, exposed to strain CHA0 (wild type) and its genetically modified derivatives in the rhizosphere of barley grown in gnotobiotic soil microcosms. Two dry-stress periods were imposed during the experiment. Derivatives of strain CHA0 included antibiotic or exopolysaccharide (EPS) overproducing strains and a dry-stress-sensitive mutant. Despite their inhibitory activity against CLB23 in vitro, neither wild-type strain CHA0, nor any of its derivatives, had a major effect on culturable and total cell numbers of CLB23 during the 23-day microcosm experiment. Populations of all inoculants declined during the two dry-stress periods, with soil water contents below 5% and plants reaching the wilting point, but they recovered after re-wetting the soil. Survival of the dry-stress-sensitive mutant of CHA0 was most affected by the dry periods; however, this did not result in an increased population density of CLB23. CONCLUSIONS: CLB comprise a large fraction of barley rhizosphere bacteria that are sensitive to the biocontrol pseudomonad CHA0 in vitro. However, in plant microcosm experiments with varying soil humidity conditions, CHA0 or its derivatives had no major impact on the survival of the highly sensitive CLB strain, CLB23, during two dry-stress periods and a re-wetting period; all co-existed well in the rhizosphere of barley plants. SIGNIFICANCE AND IMPACT OF THE STUDY: Results indicate a lack of interaction between the biocontrol pseudomonad CHA0 and a sensitive CLB when the complexity increases from agar plate assays to plant microcosm experiments. This suggests the occurrence of low levels of antibiotic production and/or that the two bacterial genera occupy different niches in the rhizosphere.

Early disturbances of gamma band dynamics in mild cognitive impairment.

Recent studies have indicated that gamma band oscillations participate in the temporal binding needed for the synchronization of cortical networks involved in short-term memory and attentional processes. To date, no study has explored the temporal dynamics of gamma band in the early stages of dementia. At baseline, gamma band analysis was performed in 29 cases with mild cognitive impairment (MCI) during the n-back task. Based on phase diagrams, multiple linear regression models were built to explore the relationship between the cognitive status and gamma oscillation changes over time. Individual measures of phase diagram complexity were made using fractal dimension values. After 1 year, all cases were assessed neuropsychologically using the same battery. A total of 16 MCI patients showed progressive cognitive decline (PMCI) and 13 remained stable (SMCI). When adjusted for gamma values at lag -2, and -3 ms, PMCI cases displayed significantly lower average changes in gamma values than SMCI cases both in detection and 2-back tasks. Gamma fractal dimension of PMCI cases displayed significantly higher gamma fractal dimension values compared to SMCI cases. This variable explained 11.8% of the cognitive variability in this series. Our data indicate that the progression of cognitive decline in MCI is associated with early deficits in temporal binding that occur during the activation of selective attention processes.

Acute neurorehabilitation: does a neurosensory and coordinated interdisciplinary programme reduce tracheostomy weaning time and weaning failure?

BACKGROUND/PURPOSE: A new coordinated interdisciplinary unit was created in the acute section of the department of clinical neurosciences, the Acute NeuroRehabilitation (NRA) unit. The objective was to evaluate the impact of the unit and its neurosensory programme on the management of tracheostomy patients in terms of reduction in the average time taken for weaning, weaning success rate and therapeutic efficiency. METHODS: This 49-month retrospective study compares 2 groups of tracheostomy patients before (n = 34) and after (n = 46) NRA intervention. The outcome measures evaluate the benefits of the NRA unit intervention (time to decannulation, weaning and complication rates) and the benefits of the coordination (time to registration in a rehabilitation centre and rate of non-compliance with standards of care). RESULTS: Weaning failure rate was reduced from 27.3% to 9.1%, no complications or recannulations were observed in the post-intervention group after weaning and time to decannulation following admission to our unit decreased from 19.13 to 12.75 days. The rate of non-compliance with patient standards of care was significantly reduced from 45% to 30% (Mann-Whitney p = 0.003). DISCUSSION/CONCLUSIONS: This interdisciplinary weaning programme helped to reduce weaning time and weaning failure, without increased complications, in the sample studied. Coordination improved the efficiency of the interdisciplinary team in the multiplicity and complexity of the different treatments.