Membrane fluidity and functional organization of the mitochondrial membranes

Fluidity, existence of phase transitions and structural organization of lipoproteins in Saccharomyces cerevisiae promitochondria has been investigated by means of X-ray diffraction, differential scanning calorimetry, spin label techniques and freeze-etching. Distinct phase transitions were found with these organelles which were shown to be partly dependent upon the lipid composition of the membranes. X-ray diffraction patterns from these membranes show that two physical states of lipids were distinguished, a crystalline-hexagonal packing characterized by a sharp 4.2Å diffraction band and a fluid (melted) state identified with a broad, diffuse band at 4.6Å. At the growth temperature (30°C) the promitochondria of the anaerobic cells contain lipids which are predominantly in the gel state with ordered lipid chains, whereas the mitochondria of the aerobic cells are in the liquid crystalline or fluid state with "melted” chains. A comparison of the phase transitions of intact membranes and extracted lipids suggests that lipid-protein interaction contributes to the high lipid phase transition temperature of promitochondria. Analysis of the spin probe data indicates a different organization of lipid and protein in such membranes, whilst the greater fluidity in the polar head group and in the lipid core of the differentiated mitochondria reflects the dynamic properties of the membrane lipids on the newly assembled proteins. Discontinuities in the ATPase Arrhenius plots are observed: with the promitochondria the discontinuity occurs near the beginning of the lipid phase transition and the ATPase enzyme may be associated with the most mobile lipid regions within the membrane- With the fully organized mitochondria it occurs well above the phase transition. A significant difference has been found in the magnetic resonance spectra from mitochondrial membranes and purified OS-ATPase. The spin label incorporated in the crude membrane is located in a more fluid region than label in an OS-ATPase system, supporting suggestion of the immobilization of lipid in the immediate vicinity of the protein. These results lend suggestion that fluid lipid regions not interacting with proteins could exist in the differentiated mitochondrial membranes and/or specific phospholipids could be involved as physiological regulators of ATPase activity by inducing a proper conformation in the enzymic activity

Validating a method for the estimate of gait spatio-temporal parameters with IMUs data on healthy and impaired people from two clinical centers

Instrumented gait analysis offers objective clinical outcome assessment. To this purpose, inertial measurement units (IMUs) represent nowadays a very effective solution due to their limited cost, ease of use and improved wearability. The aim of this study was to apply a well-documented IMU-based method to measure gait spatio-temporal parameters in a large number of healthy and gait-impaired subjects, and evaluate its robustness and validity across two clinical centers. Overall, the results of this work represent a robust and reliable foundation for the clinical use of the proposed IMU based method for gait parameters estimation

THE MARKETING STYLE OF ADVISORY SERVICES FOR CORN AND SOYBEANS IN 1995

The 1995 marketing styles for the 25 market advisory service programs included in the AgMAS Project were developed in two steps. The first step was the construction of a detailed "menu" of the tools and strategies used by each of the advisory programs in marketing corn and soybeans. The menu describes the type of pricing tool, frequency of transactions, and magnitude of transactions. The second step was the development of a daily index of the net amount sold by each market advisory program. To construct such an index, the various futures, options, and cash positions recommended for a program on a given day were weighted by the respective position "delta." When the daily values of the index were plotted for the entire marketing period, the marketing "profile" for a program was generated. The results show that advisory programs made a relatively small number of recommendations that primarily involved cash marketing strategies, not futures and options, non-cash marketing recommendations were typically held open for a short period of time, and the re-harvest amount sold averaged 35 percent for corn and 30 percent for soybeans.advisory services, pricing tools, pricing strategies, assessment of recommendations, D4, C8, D8, M3, Q0, Marketing,

Thermal stability and aggregation of sulfolobus solfataricus b-glycosidase are dependent upon the N-e-methylation of specific lysyl residues: critical role of in vivo post-translational modifications.

Methylation in vivo is a post-translational modification observed in several organisms belonging to eucarya, bacteria, and archaea. Although important implications of this modification have been demonstrated in several eucaryotes, its biological role in hyperthermophilic archaea is far from being understood. The aim of this work is to clarify some effects of methylation on the properties of β-glycosidase from Sulfolobus solfataricus, by a structural comparison between the native, methylated protein and its unmethylated counterpart, recombinantly expressed in Escherichia coli. Analysis by Fourier transform infrared spectroscopy indicated similar secondary structure contents for the two forms of the protein. However, the study of temperature perturbation by Fourier transform infrared spectroscopy and turbidimetry evidenced denaturation and aggregation events more pronounced in recombinant than in native β-glycosidase. Red Nile fluorescence analysis revealed significant differences of surface hydrophobicity between the two forms of the protein. Unlike the native enzyme, which dissociated into SDS-resistant dimers upon exposure to the detergent, the recombinant enzyme partially dissociated into monomers. By electrospray mapping, the methylation sites of the native protein were identified. A computational analysis of β-glycosidase three-dimensional structure and comparisons with other proteins from S. solfataricus revealed analogies in the localization of methylation sites in terms of secondary structural elements and overall topology. These observations suggest a role for the methylation of lysyl residues, located in selected domains, in the thermal stabilization of β-glycosidase from S. solfataricu

MORPH: A Reference Architecture for Configuration and Behaviour Self-Adaptation

An architectural approach to self-adaptive systems involves runtime change of system configuration (i.e., the system's components, their bindings and operational parameters) and behaviour update (i.e., component orchestration). Thus, dynamic reconfiguration and discrete event control theory are at the heart of architectural adaptation. Although controlling configuration and behaviour at runtime has been discussed and applied to architectural adaptation, architectures for self-adaptive systems often compound these two aspects reducing the potential for adaptability. In this paper we propose a reference architecture that allows for coordinated yet transparent and independent adaptation of system configuration and behaviour

Usos potenciales de la madera de roble europeo y fresno americano cultivados en la provincia de Buenos Aires, Argentina

- Spavento, E. Ing. Forestal, Docente-Investigadora, Xilotecnología y Profesional Independiente. Facultad de Ciencias Agrarias y Forestales, UNLP. [email protected] - Keil, G. Ing. Forestal M. Sc., Docente-Investigador, Xilotecnología e Industrias de Transformación Mecánica. Facultad de Ciencias Agrarias y Forestales, UNLP. [email protected] - Murace, M. Licenciada en Biología, Docente-Investigadora, Protección Forestal. Facultad de Ciencias Agrarias y Forestales, UNLP. [email protected] - Luján M . Doctora en Ciencias Naturales, Docente-Investigadora, Facultad de Ciencias Naturales y Museo, UNLP. CIC, PBA. - Bertoli, B Ingeniero Forestal, Profesional Independiente.Los usos de una madera están estrechamente relacionados a sus características tecnológicas. Para utilizar con fiabilidad la madera de roble europeo (Quercus robur L.) y fresno americano (Fraxinus pennsylvanica Marsh.) cultivada en la provincia de Buenos Aires (Argentina) es necesario conocer sus propiedades físicomecánicas y su durabilidad. El objetivo de este trabajo fue determinar, mediante ensayos estandarizados, las características tecnológicas de la madera de roble y fresno, implantados en la provincia de Buenos Aires, con el propósito de definir sus usos. Las propiedades físicas determinadas fueron: contenido de humedad (IRAM 9532), densidades aparentes (IRAM 9544), cambios dimensionales (IRAM 9543). Las propiedades mecánicas determinadas fueron: dureza Janka (IRAM 9570), flexión estática (IRAM 9542), corte paralelo a las fibras (IRAM 9596), compresión perpendicular y paralela a las fibras (IRAM 9547 y 9541 respectivamente). La durabilidad natural se estimó aplicando la norma IRAM 9518. Se estudió además la estructura del leño de ambas especies, a nivel macro y microscópico, con el fin de relacionar estas características con las propiedades tecnológicas. Para ello se cuantificaron los siguientes caracteres: longitud, espesor de pared y diámetro del lumen de fibras y diámetro de vasos mayores. Ambas maderas resultaron medianamente estables, de densidad media alta y durables. De acuerdo con esto las maderas de roble europeo y fresno americano cultivadas en Argentina son aptas para una amplia gama de usos: elementos deportivos, mangos de herramientas, muebles, escaleras, molduras, puertas, solados interiores y exteriores y elementos estructurales como vigas y columnas, entre otros

The effect of a secondary task on kinematics during turning in Parkinson's disease with mild to moderate impairment

Patients with Parkinson's disease (PD) show typical gait asymmetries. These peculiar motor impairments are exacerbated by added cognitive and/or mechanical loading. However, there is scarce literature that chains these two stimuli. The aim of this study was to investigate the combined effects of a dual task (cognitive task) and turning (mechanical task) on the spatiotemporal parameters in mild to moderate PD. Participants (nine patients with PD and nine controls (CRs)) were evaluated while walking at their self-selected pace without a secondary task (single task), and while repeating the days of the week backwards (dual task) along a straight direction and a 60 degrees and 120 degrees turn. As speculated, in single tasking, PD patients preferred to walk with a shorter stride length (p< 0.05) but similar timing parameters, compared to the CR group; in dual tasking, both groups walked slower with shorter strides. As the turn angle increased, the speed will be reduced (p< 0.001), whereas the ground-foot contact will become greater (p< 0.001) in all the participants. We showed that the combination of a simple cognitive task and a mechanical task (especially at larger angles) could represent an important training stimulus in PD at the early stages of the pathology

Outcome stability of orthopaedic treatment of skeletal Class III malocclusion: A study of prognostic agreement between three models

Introduction: Long-term stability of the treatment outcome of skeletal Class III malocclusion is always not achievable, thereforeseveral prediction models of stability of orthopaedic treatment of the Class III malocclusion have been proposed. Aim: This cross-sectional study was aimed at the evaluation of the prognostic agreement and association between three differentprediction models based on skeletal parameters recorded on lateral cephalograms. Materials and methods: A total of 75 subjects (34 females and 41 males, age range 7-11, mean age 9.1±1.2years) having skeletal ClassIII malocclusion were included in the study. Prediction models reported by Baccetti et al. 2004 (prediction model 1), Moon et al.2005 (prediction model 2) and Yoshida et al. 2006 (prediction model 3), were considered. Percentage agreement and unweighted kappa coefficient evaluated the agreement between the prediction models in terms of stable or unstable cases. Multiple regressions were run to evaluate the association between the absolute scores obtained from each of the prediction model (prediction scores). Results: Percentage agreement ranged from 77.3% (models 2 and 3) to 89.3%, (models 1 and 2) and corresponding unweighted kappa coefficients ranged from 0.099 (models 1 and 3) to 0.205 (models 2 and 3). The prediction score from model 3 was significantly associated with those from both the other models; on the contrary, prediction scores from models 1 and 2 were not significantly associated. Conclusions: Agreement in terms of stability or instability outcome derived from these models is only partial and not satisfactory,even though significant association between the prediction scores denotes a common biological meaning of the models

Determinants of obesity in Italian adults : the role of taste sensitivity, food liking, and food neophobia

Recent evidence has suggested that factors related to sensory perception may explain excess weight. The objective of this study was to consider multiple aspects while investigating the phenomenon of obesity. One goal was to compare taste acuity (taste threshold and density of fungiform papillae) in both normal weight and obese subjects. Thresholds for 4 basic tastes and the fat stimulus were investigated. A second research goal was to study the relationship between food neophobia and food liking according to the body mass index and taste sensitivity. The results showed that obese subjects seem to have higher threshold values and a reduced number of fungiform papillae than do normal weight subjects. Food neophobia did not vary with nutritional status, whereas differences were found for food liking, with obese subjects showing significantly higher liking ratings for high energy dense products compared with normal weight subjects

Microglia in prion diseases: Angels or demons?

Prion diseases are rare transmissible neurodegenerative disorders caused by the accumulation of a misfolded isoform (PrPSc) of the cellular prion protein (PrPC) in the central nervous system (CNS). Neuropathological hallmarks of prion diseases are neuronal loss, astrogliosis, and enhanced microglial proliferation and activation. As immune cells of the CNS, microglia participate both in the maintenance of the normal brain physiology and in driving the neuroinflammatory response to acute or chronic (e.g., neurodegenerative disorders) insults. Microglia involvement in prion diseases, however, is far from being clearly understood. During this review, we summarize and discuss controversial findings, both in patient and animal models, suggesting a neuroprotective role of microglia in prion disease pathogenesis and progression, or\u2014conversely\u2014a microglia-mediated exacerbation of neurotoxicity in later stages of disease. We also will consider the active participation of PrPC in microglial functions, by discussing previous reports, but also by presenting unpublished results that support a role for PrPC in cytokine secretion by activated primary microglia