The pareto-stability concept is a natural solution concept for discrete matching markets with indifferences

In a decentralized setting the game-theoretical predictions are that only strong blockings are allowed to rupture the structure of a matching. This paper argues that, under indifferences, also weak blockings should be considered when these blockings come from the grand coalition. This solution concept requires stability plus Pareto optimality. A characterization of the set of Pareto-stable matchings for the roommate and the marriage models is provided in terms of individually rational matchings whose blocking pairs, if any, are formed with unmatched agents. These matchings always exist and give an economic intuition on how blocking can be done by non-trading agents, so that the transactions need not be undone as agents reach the set of stable matchings. Some properties of the Pareto-stable matchings shared by the Marriage and Roommate models are obtained.

The stability of the equilibrium outcomes in the admission games induced by stable matching rules

A stable matching rule is used as the outcome function for the Admission game where colleges behave straightforwardly and the students` strategies are given by their preferences over the colleges. We show that the college-optimal stable matching rule implements the set of stable matchings via the Nash equilibrium (NE) concept. For any other stable matching rule the strategic behavior of the students may lead to outcomes that are not stable under the true preferences. We then introduce uncertainty about the matching selected and prove that the natural solution concept is that of NE in the strong sense. A general result shows that the random stable matching rule, as well as any stable matching rule, implements the set of stable matchings via NE in the strong sense. Precise answers are given to the strategic questions raised.

Production and properties of xylanases from Aspergillus terricola Marchal and Aspergillus ochraceus and their use in cellulose pulp bleaching

Aspergillus terricola and Aspergillus ochraceus, isolated from Brazilian soil, were cultivated in Vogel and Adams media supplemented with 20 different carbon sources, at 30 A degrees C, under static conditions, for 120 and 144 h, respectively. High levels of cellulase-free xylanase were produced in birchwood or oat spelt xylan-media. Wheat bran was the most favorable agricultural residue for xylanase production. Maximum activity was obtained at 60 A degrees C and pH 6.5 for A. terricola, and 65 A degrees C and pH 5.0 for A. ochraceus. A. terricola xylanase was stable for 1 h at 60 A degrees C and retained 50% activity after 80 min, while A. ochraceus xylanase presented a t (50) of 10 min. The xylanases were stable in an alkali pH range. Biobleaching of 10 U/g dry cellulose pulp resulted in 14.3% delignification (A. terricola) and 36.4% (A. ochraceus). The brightness was 2.4-3.4% ISO higher than the control. Analysis in SEM showed defibrillation of the microfibrils. Arabinase traces and beta-xylosidase were detected which might act synergistically with xylanase.

Production of xylanase by Aspergilli using alternative carbon sources: application of the crude extract on cellulose pulp biobleaching

The ability of xylanolytic enzymes produced by Aspergillus fumigatus RP04 and Aspergillus niveus RP05 to promote the biobleaching of cellulose pulp was investigated. Both fungi grew for 4-5 days in liquid medium at 40A degrees C, under static conditions. Xylanase production was tested using different carbon sources, including some types of xylans. A. fumigatus produced high levels of xylanase on agricultural residues (corncob or wheat bran), whereas A. niveus produced more xylanase on birchwood xylan. The optimum temperature of the xylanases from A. fumigatus and A. niveus was around 60-70A degrees C. The enzymes were stable for 30 min at 60A degrees C, maintaining 95-98% of the initial activity. After 1 h at this temperature, the xylanase from A. niveus still retained 85% of initial activity, while the xylanase from A. fumigatus was only 40% active. The pH optimum of the xylanases was acidic (4.5-5.5). The pH stability for the xylanase from A. fumigatus was higher at pH 6.0-8.0, while the enzyme from A. niveus was more stable at pH 4.5-6.5. Crude enzymatic extracts were used to clarify cellulose pulp and the best result was obtained with the A. niveus preparation, showing kappa efficiency around 39.6% as compared to only 11.7% for that of A. fumigatus.

Molecular adaptability of nucleoside diphosphate kinase b from trypanosomatid parasites: stability, oligomerization and structural determinants of nucleotide binding

Nucleoside diphosphate kinases play a crucial role in the purine-salvage pathway of trypanosomatid protozoa and have been found in the secretome of Leishmania sp., suggesting a function related to host-cell integrity for the benefit of the parasite. Due to their importance for housekeeping functions in the parasite and by prolonging the life of host cells in infection, they become an attractive target for drug discovery and design. In this work, we describe the first structural characterization of nucleoside diphosphate kinases b from trypanosomatid parasites (tNDKbs) providing insights into their oligomerization, stability and structural determinants for nucleotide binding. Crystallographic studies of LmNDKb when complexed with phosphate, AMP and ADP showed that the crucial hydrogen-bonding residues involved in the nucleotide interaction are fully conserved in tNDKbs. Depending on the nature of the ligand, the nucleotide-binding pocket undergoes conformational changes, which leads to different cavity volumes. SAXS experiments showed that tNDKbs, like other eukaryotic NDKs, form a hexamer in solution and their oligomeric state does not rely on the presence of nucleotides or mimetics. Fluorescence-based thermal-shift assays demonstrated slightly higher stability of tNDKbs compared to human NDKb (HsNDKb), which is in agreement with the fact that tNDKbs are secreted and subjected to variations of temperature in the host cells during infection and disease development. Moreover, tNDKbs were stabilized upon nucleotide binding, whereas HsNDKb was not influenced. Contrasts on the surface electrostatic potential around the nucleotide-binding pocket might be a determinant for nucleotide affinity and protein stability differentiation. All these together demonstrated the molecular adaptation of parasite NDKbs in order to exert their biological functions intra-parasite and when secreted by regulating ATP levels of host cells.

The effect of methanol on the stability of Pt/C and Pt-RuO(x)/C catalysts

The behavior of Pt/C and Pt-RuO(x)/C electrodes subjected to a larger number of potential scans and constant potential for prolonged time periods was investigated in the absence and presence of methanol. The structural changes were analyzed on the basis of the modifications observed in the X-ray diffraction pattern of the catalysts. Carbon monoxide stripping experiments were performed before and after the potential scans, thus enabling analysis of the behavior of the electrochemically active surface area. The resulting solutions were examined by inductively coupled plasma mass spectrometry (ICP-MS). There was reduction in the electrochemically active surface area, as well as increase in crystallite size and dissolution of catalyst components after the potential scan tests. Catalyst degradation was more pronounced in the presence of methanol, and cyclic potential conditions accelerate the degradation mechanisms. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

STATIC IMAGES WITH DIFFERENT INDUCED INTENSITIES OF HUMAN BODY MOVEMENTS AFFECT SUBJECTIVE TIME

Modulation of subjective time was examined using static images eliciting perceptions of different intensities of body movement. Undergraduate students were exposed to photographs of dancer sculptures in different dance positions for 36 sec. and asked to estimate the exposure duration. Lower movement intensities were related to shorter estimated durations. Mean durations for images of unmoving dancers were underestimated and for dancers taking a ballet step were overestimated. Temporal estimations were also related to the order of presentation of the stimuli, which suggested that subjective time estimations were influenced by the experimental context. Subjective time is related not only to the visual perception of moving images, but also of elicited perceptions of movement in static images, suggesting an embodiment effect on subjective time estimation.

Detrusor overactivity is associated with downregulation of large-conductance calcium- and voltage-activated potassium channel protein

Chang S, Gomes CM, Hypolite JA, Marx J, Alanzi J, Zderic SA, Malkowicz B, Wein AJ, Chacko S. Detrusor overactivity is associated with downregulation of large-conductance calcium-and voltage-activated potassium channel protein. Am J Physiol Renal Physiol 298: F1416-F1423, 2010. First published April 14, 2010; doi: 10.1152/ajprenal.00595.2009.-Large-conductance voltage-and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet obstructioninduced DO is associated with downregulation of BK channels and whether BK channels affect myosin light chain 20 (MLC(20)) phosphorylation in detrusor smooth muscle (DSM). Partial bladder outlet obstruction (PBOO) was surgically induced in male New Zealand White rabbits. The rabbit PBOO model shows decreased voided volumes and increased voiding frequency. DSM from PBOO rabbits also show enhanced spontaneous contractions compared with control. Both BK channel alpha- and beta-subunits were significantly decreased in DSM from PBOO rabbits. Immunostaining shows BK beta mainly expressed in DSM, and its expression is much less in PBOO DSM compared with control DSM. Furthermore, a translational study was performed to see whether the finding discovered in the animal model can be translated to human patients. The urodynamic study demonstrates several overactive DSM contractions during the urine-filling stage in benign prostatic hyperplasia (BPH) patients with DO, while DSM is very quiet in BPH patients without DO. DSM biopsies revealed significantly less BK channel expression at both mRNA and protein levels. The degree of downregulation of the BK beta-subunit was greater than that of the BK alpha-subunit, and the downregulation of BK was only associated with DO, not BPH. Finally, the small interference (si) RNA-mediated downregulation of the BK beta-subunit was employed to study the effect of BK depletion on MLC(20) phosphorylation. siRNA-mediated BK channel reduction was associated with an increased MLC(20) phosphorylation level in cultured DSM cells. In summary, PBOO-induced DO is associated with downregulation of BK channel expression in the rabbit model, and this finding can be translated to human BPH patients with DO. Furthermore, downregulation of the BK channel may contribute to DO by increasing the basal level of MLC(20) phosphorylation.

Anti-Group A Streptococcal Vaccine Epitope STRUCTURE, STABILITY, AND ITS ABILITY TO INTERACT WITH HLA CLASS II MOLECULES

Streptococcus pyogenes infections remain a health problem in several countries due to poststreptococcal sequelae. We developed a vaccine epitope (StreptInCor) composed of 55 amino acids residues of the C-terminal portion of the M protein that encompasses both T and B cell protective epitopes. The nuclear magnetic resonance (NMR) structure of the StreptInCor peptide showed that the structure was composed of two microdomains linked by an 18-residue alpha-helix. A chemical stability study of the StreptInCor folding/unfolding process using far-UV circular dichroism showed that the structure was chemically stable with respect to pH and the concentration of urea. The T cell epitope is located in the first microdomain and encompasses 11 out of the 18 alpha-helix residues, whereas the B cell epitope is in the second microdomain and showed no alpha-helical structure. The prediction of StreptInCor epitope binding to different HLA class II molecules was evaluated based on an analysis of the 55 residues and the theoretical possibilities for the processed peptides to fit into the P1, P4, P6, and P9 pockets in the groove of several HLA class II molecules. We observed 7 potential sites along the amino acid sequence of StreptInCor that were capable of recognizing HLA class II molecules (DRB1*, DRB3*, DRB4*, and DRB5*). StreptInCoroverlapping peptides induced cellular and humoral immune responses of individuals bearing different HLA class II molecules and could be considered as a universal vaccine epitope.

Muscle Activation During Four Pilates Core Stability Exercises in Quadruped Position

Queiroz BC, Cagliari MF, Amorim CF, Sacco IC. Muscle activation during four Pilates core stability exercises in quadruped position. Arch Phys Med Rehabil 2010;91: 86-92. Objective: To compare the activity of stabilizing trunk and hip muscles in 4 variations of Pilates stabilizing exercises in the quadruped position. Design: Repeated-measures descriptive study. Setting: A biomechanics laboratory at a university school of medicine. Participants: Healthy subjects (N=19; mean age +/- SD, 31 +/- 5y; mean weight +/- SD, 60 +/- 11 kg; mean height +/- SD, 166 +/- 9cm) experienced in Pilates routines. Interventions: Surface electromyographic signals of iliocostalis, multifidus, gluteus maximus, rectus abdominis, and external and internal oblique muscles were recorded in 4 knee stretch exercises: retroverted pelvis with flexed trunk; anteverted pelvis with extended trunk; neutral pelvis with inclined trunk; and neutral pelvis with trunk parallel to the ground. Main Outcome Measures: Root mean square values of each muscle and exercise in both phases of hip extension and flexion, normalized by the maximal voluntary isometric contraction. Results: The retroverted pelvis with flexed trunk position led to significantly increased external oblique and gluteus maximus muscle activation. The anteverted pelvis with trunk extension significantly increased multifidus muscle activity. The neutral pelvis position led to significantly lower activity of all muscles. Rectus abdominis muscle activation to maintain body posture was similar in all exercises and was not influenced by position of the pelvis and trunk. Conclusions: Variations in the pelvic and trunk positions in the knee stretch exercises change the activation pattern of the multifidus, gluteus maximus, rectus abdominis, and oblique muscles. The lower level of activation of the rectus abdominis muscle suggests that pelvic stability is maintained in the 4 exercise positions.

Static Knee Alignment Measurements among Caucasians and African Americans: The Johnston County Osteoarthritis Project

Objective. To determine if knee alignment measures differ between African Americans and Caucasians without radiographic knee osteoarthritis (rOA). Methods. A single knee was randomly selected from 175 participants in the Johnston County Osteoarthritis Project without rOA in either knee. Anatomic axis, condylar, tibia] plateau, and condylar plateau angles were measured by I radiologist; means were compared and adjusted for age and body mass index (BMI). Results. There were no significant differences in knee alignment measurements between Caucasians and African Americans among men or women. Conclusion. Observed differences in knee rOA occurrence between African Americans and Caucasians are not explained by differences in static knee alignment. (First Release July 15 2009; J Rheumatol 2009;36:1987-90; doi: 10.3899/jrheum.081294)

Influence of ventilatory settings on static and functional haemodynamic parameters during experimental hypovolaemia

Background and objective The influence of ventilatory settings on static and functional haemodynamic parameters during mechanical ventilation is not completely known. The purpose of this study was to evaluate the effect of positive end-expiratory pressure, tidal volume and inspiratory to expiratory time ratio variations on haemodynamic parameters during haemorrhage and after transfusion of shed blood. Methods Ten anaesthetized pigs were instrumented and mechanically ventilated with a tidal volume of 8 ml kg(-1), a positive end-expiratory pressure of 5 cmH(2)O and an inspiratory to expiratory ratio of 1 : 2. Then, they were submitted in a random order to different ventilatory settings (tidal volume 16 ml kg(-1), positive end-expiratory pressure 15 cmH(2)O or inspiratory to expiratory time ratio 2: 1). Functional and static haemodynamic parameters (central venous pressure, pulmonary artery occlusion pressure, right ventricular end-diastolic volume and pulse pressure variation) were evaluated at baseline, during hypovolaemia (withdrawal of 20% of estimated blood volume) and after an infusion of withdrawn blood (posttransfusion). Results During baseline, a positive end-expiratory pressure of 15cmH(2)O significantly increased pulmonary artery occlusion pressure from 14.6 +/- 1.6 mmHg to 17.4 +/- 1.7 mmHg (P<0.001) and pulse pressure variation from 15.8 +/- 8.5% to 25.3 +/- 9.5% (P<0.001). High tidal volume increased pulse pressure variation from 15.8 8.5% to 31.6 +/- 10.4% (P<0.001), and an inspiratory to expiratory time ratio of 2: 1 significantly increased only central venous pressure. During hypovolaemia, high positive end-expiratory pressure influenced all studied variables, and high tidal volume strongly increased pulse pressure variation (40.5 +/- 12.4% pre vs. 84.2 +/- 19.1 % post, P<0.001). The inversion of the inspiratory to expiratory time ratio only slightly increased filling pressures during hypovolaemia, without without affecting pulse pressure variation or right ventricle end-diastolic volume. Conclusion We concluded that pulse pressure variation measurement is influenced by cyclic variations in intrathoracic pressure, such as those caused by augmentations in tidal volume. The increase in mean airway pressure caused by positive end-expiratory pressure affects cardiac filling pressures and also pulse pressure variation, although to a lesser extent. Inversion of the inspiratory to expiratory time ratio does not induce significant changes in static and functional haemodynamic parameters. Eur J Anaesthesiol 26:66-72 (c) 2009 European Society of Anaesthesiology.

High voltage electrical stimulation as an alternative treatment for chronic ulcers of the lower limbs

High voltage electrical stimulation has been recommended as a means of accelerating the wound healing process. The effects of high voltage electrical stimulation were evaluated in the treatment of three volunteers with chronic ulcers of the lower limbs. After fifteen weeks of treatment, a reduction was found in the area of all the ulcers, suggesting that high voltage electric stimulation is an effective therapeutic option for chronic ulcers.

The synergy between structural stability and DNA-binding controls the antibody production in EPC/DOTAP/DOPE liposomes and DOTAP/DOPE lipoplexes

We present a comparative study of the physico-chemical properties, in vitro cytotoxicity and in vivo antibody production of surface-complexed DNA in EPC/DOTAP/DOPE (50/25/25% molar) liposomes and DOTAP/DOPE (50/50% molar) lipoplexes. The study aims to correlate the biological behavior and structural properties of the lipid carriers. We used DNA-hsp65, whose naked action as a gene vaccine against tuberculosis has already been demonstrated. Additionally, surface-complexed DNA-hsp65 in EPC/DOTAP/DOPE (50/25/25% molar) liposomes was effective as a single-dose tuberculosis vaccine. The results obtained showed that the EPC inclusion stabilized the DOTAP/DOPE structure, producing higher melting temperature and lower zeta potential despite a close mean hydrodynamic diameter. Resemblances in morphologies were identified in both structures, although a higher fraction of loaded DNA was not electrostatically bound in EPC/DOTAP/DOPE. EPC also induced a striking reduction in cytotoxicity, similar to naked DNA-hsp65. The proper immune response lead to a polarized antibody production of the IgG2a isotype, even for the cytotoxic DOTAP/DOPE. However, the antibody production was detected at 15 and 30 days for DOTAP/DOPE and EPC/DOTAP/DOPE, respectively. Therefore, the in vivo antibody production neither correlates with the in vitro cytotoxicity, nor with the structural stability alone. The synergistic effect of the structural stability and DNA electrostatic binding upon the surface of structures account for the immunological effects. By adjusting the composition to generate proper packing and cationic lipid/DNA interaction, we allow for the optimization of liposome formulations for required immunization or gene therapy. In a specific manner, our results contribute to studies on the tuberculosis therapy and vaccination. (C) 2009 Elsevier B.V. All rights reserved.

High-voltage electrical burn injuries: Functional upper extremity assessment

High-voltage electric injuries have many manifestations, and an important complication is the damage of the central/peripheral nervous system. The purpose of this work was to assess the upper limb dysfunction in patients injured by high-voltage current. The evaluation consisted of analysis of patients` records, cutaneous-sensibility threshold, handgrip and pinch strength and a specific questionnaire about upper limb dysfunctions (DASH) in 18 subjects. All subjects were men; the average age at the time of the injury was 38 years. Of these, 72% changed job/retired after the injury. The current entrance was the hand in 94% and grounding in the lower limb in 78%. The average burned surface area (BSA) was 8.6%. The handgrip strength of the injured limb was reduced (p < 0.05) and so also that of the three pinch types. The relationship between the handgrip strength and the DASH was statistically significant (p < 0.001) as well as the relationship between the three pinch types (p <= 0.02) to the injured limb. The ability to perceive cutaneous touch/pressure was decreased in the burnt hand, principally in the median nerve area. These data indicate a reduction of the hand muscular strength and sensibility, reducing the function of the upper limb in patients who received high-voltage electrical shock. (C) 2008 Elsevier Ltd and ISBI. All rights reserved.