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How brain damage after stroke is related to specific clinical manifestation and recovery is incompletely understood. We studied cognitive reserve (CR) in stroke patients by two types of measurements: (i) objectively verifiable static proxies (i.e., education, occupational attainment), and (ii) subjective, dynamic proxies based on patient testimony in response to a questionnaire. We hypothesized that one or both of these types of CR measurements might correlate positively with patient cognitive performance during the post-acute and chronic phases of recovery.
Thirty-four stroke patients underwent neuropsychological assessment at 2, 6 and 24 months after stroke onset. In chronic stage at 24+ months, self-rating assessments of cognitive performance in daily life and social integration were obtained. CR before and after stroke was estimated using static proxies and dynamic proxies were obtained using the Cognitive Reserve Scale (CRS-Pre-stroke, CRS-Post-stroke).
CRS-Pre-stroke and CRS-Post-stroke showed significant mean differences. Dynamic proxies showed positive correlation with self-assessment of attention, metacognition, and functional ability in chronic stage. In contrast, significant correlations between static proxies and cognitive recovery were not found.
Dynamic proxies of CR were positively correlated with patients’ perception of their functional abilities in daily life. To best guide cognitive prognosis and treatment, we propose that dynamic proxies of CR should be included in neuropsychological assessments of patients with brain damage.
This is a copy of the slides presented at the meeting but not formally written up for the volume.
The growth of heterostructures combining oxide materials is a new strategy to design novel artificial multifunctional materials with interesting behaviors ruled by the interface. There has been increasing interest in heterostructures combining oxides with different functionalities and ground states competing at the interface. In structures involving oxides, interfaces are especially complex and various factors like interface disorder and roughness, epitaxial strain, polarity mismatch etc., are responsible for modified properties at the interface over nanometer length scales. In this presentation we will focus on cuprate / manganite heterostructures made of YBa2Cu3O7 (YBCO) and La1-xCaxMnO3 (LCMO), where the Ca content is varied over a wide range. The manganite grows epitaxially on the superconductor with different degrees of strain depending on the Ca content. For x=0.3 the manganite is ferromagnetic what causes a strong depression of the superconducting order parameter at the YBCO side. Interestingly, there is also a depression of the ferromagnetic moment at the interface suggesting charge transfer (electrons) from the manganite into the YBCO. This is confirmed growing superlattices combining YBCO with the parent manganite compound with x=0, which is nominally an AF insulator. Actually, for LMO thickness below 6 unit cells (2,4 nm) the layers are non magnetic and insulating as expected. However, above this LMO thickness (6 unit cells) we show that superconductivity is strongly suppressed and ferromagnetism is induced at the interface providing a strong evidence for the charge transfer scenario. The control of layer bulk doping by charge transfer at the interface opens new possibilities of tailoring the electronic states at the interface for the design of novel functionalities and devices. Work supported by CICYT MAT2005 06024 C02-02 and DOE.
Emergency physicians play a frontline role in hospital disaster responses and require appropriate training.
The aim of the current study was to pilot and compare the effectiveness of two emergency preparedness teaching interventions: the first employing traditional lecture-based instruction (LEC) and the second utilizing interactive simulation/game-based teaching (SIM).
A two-group randomized pre- and post-test design was implemented into the didactic curriculum of the Emergency Medicine (EM) Residency Training Program at the San Lucas Episcopal Hospital in Ponce, Puerto Rico. Residents (n=23) completed either a LEC (control) or SIM teaching module (single day, one to two hours) focusing on emergency preparedness concepts, disaster-related clinical decision-making, and physician responsibilities during hospital disaster protocols. Knowledge-based multiple-choice exams and scenario-based competency exams were administered at three different time points: one-week pre-intervention, immediately post-training, and two-weeks post-training. Test scores were compared between groups at each time point using the Mann-Whitney U test.
Following the teaching interventions, no significant differences were found between the LEC group versus the SIM group in knowledge-based exam performance (LEC 81.1%[9.4] vs. SIM 74.9%[12.1]; U=42.50, p=0.15) and scenario-based exam performance (LEC 80.0%[9.7] vs. SIM 80.2%[9.2]; U=62.00, p=0.83), suggesting both teaching methods were similarly effective. Indeed, knowledge-based exam scores improved two-fold and scenario-based exam scores improved by over 50% immediately following training relative to baseline exam scores. Two-weeks post-training, a significant decrease in scenario-based exam performance was found in the LEC group relative to the SIM group (LEC 63.1%[11.6] vs. SIM 75.4%[11.5]; U=91.50, p=0.036), suggesting residents who train with simulations show greater retention of scenario-based concepts compared to those who train with lecture-based training alone.
The current study highlights the potential dual value of incorporating simulation training in EM emergency preparedness curriculums in improving both knowledge and concept retention of physician disaster responsibilities.
Trichomonas vaginalis induces cellular damage to the host cells (cytotoxicity) through the proteolytic activity of multiple proteinases of the cysteine type (CPs). Some CPs are modulated by environmental factors such as iron, zinc, polyamines, etc. Thus, the goal of this study was to assess the effect of glucose on T. vaginalis cytotoxicity, proteolytic activity and the particular role of TvCP2 (TVAG_057000) during cellular damage. Cytotoxicity assays showed that glucose-restriction (GR) promotes the highest HeLa cell monolayers destruction (~95%) by trichomonads compared to those grown under high glucose (~44%) condition. Zymography and Western blot using different primary antibodies showed that GR increased the proteolytic activity, amount and secretion of certain CPs, including TvCP2. We further characterized the effect of glucose on TvCP2. TvCP2 increases in GR, localized in vesicles close to the plasma membrane and on the surface of T. vaginalis. Furthermore, pretreatment of GR-trichomonads with an anti-TvCP2r polyclonal antibody specifically reduced the levels of cytotoxicity and apoptosis induction to HeLa cells in a concentration-dependent manner. In conclusion, our data show that GR, as a nutritional stress condition, promotes trichomonal cytotoxicity to the host cells, increases trichomonad proteolytic activity and amount of CPs, such as TvCP2 involved in cellular damage.
Stereo-electroencephalography (SEEG) has been shown to be a valuable tool for the anatomo-electroclinic definition of the epileptogenic zone (EZ) in some patients with medically refractory epilepsy considered for surgery. In Spain, many of those patients are not offered this diagnostic procedure. The objective of our health technology assessment (HTA) report was to evaluate the effectiveness, safety and cost-effectiveness of SEEG to define the EZ in patients with refractory epilepsy considered for surgery compared to no SEEG intervention (i.e. remaining with further antiepileptic drugs).
We undertook a systematic review with meta-analyses on the effectiveness and safety of SEEG. A cost-effectiveness analysis was conducted using a Markov model which simulates the costs and health outcomes of individuals for a lifetime horizon from the perspective of the Spanish National Health Service (NHS). The effectiveness measure was quality-adjusted life years (QALYs). We ran extensive sensitivity analyses, including a probabilistic sensitivity analysis.
The EZ was found in 92 percent of patients who underwent SEEG, 72 percent were eligible for epilepsy surgery and 33 percent were free of seizures after surgery (47 percent of those who received surgery). Any complications related to insertion and monitoring of SEEG and the subsequent intervention occurred in 1.3 percent of patients. In the base case analysis, SEEG led to higher QALYs and healthcare costs with an estimated incremental cost-effectiveness ratio of EUR 10,368 (USD 12,217) per QALY. The sensitivity analyses showed that the results of the study were robust.
SEEG is a cost-effective technology in patients with refractory epilepsy considered for surgery when compared to no SEEG intervention.
Boring sponges are an important component of bioeroder assemblages in tropical coral reefs. They are considered as a potential threat for coral reef health, and the increase of dead corals is expected to promote their abundance. The relationship between the availability of dead coral substrata and the development of boring sponge assemblages was evaluated during El Niño 2015–16 at five reefs from Zihuatanejo, Guerrero, Mexico. Environment and substrate quality were assessed. Overall, environment conditions remained normal in relation to previous studies in the area. Only water temperature showed unusually high records at all sites and coincided with bleaching and mortality of corals, possibly caused by the effects of the El Niño event. Abundance of boring sponges in dead corals and coral rubble was lower than during previous studies. Although sponge abundance was not directly related to cover of both dead corals and coral rubble, cover of dead corals showed a high correlation with the variation in the structure of sponge assemblages across sites. Cliona vermifera dominated sponge assemblages at all sites, and its abundance was high under conditions of high cover of live corals and low cover of bleached corals. Since overall sponge abundance responded in a similar way, these results suggest that boring sponge assemblages dominated by C. vermifera are enhanced by conditions favourable for corals. Our results imply that El Niño events in the Mexican Pacific are not likely to cause immediate population outbreaks of boring sponges.
Grounded in self-determination theory, the aim of this study was to develop a scale with adequate psychometric properties to assess motivation for teaching and to explain some outcomes of secondary education teachers at work. The sample comprised 584 secondary education teachers. Analyses supported the five-factor model (intrinsic motivation, identified regulation, introjected regulation, external regulation and amotivation) and indicated the presence of a continuum of self-determination. Evidence of reliability was provided by Cronbach’s alpha, composite reliability and average variance extracted. Multigroup confirmatory factor analyses supported the partial invariance (configural and metric) of the scale in different sub-samples, in terms of gender and type of school. Concurrent validity was analyzed by a structural equation modeling that explained 71% of the work dedication variance and 69% of the boredom at work variance. Work dedication was positively predicted by intrinsic motivation (ß = .56, p < .001) and external regulation (ß = .29, p < .001) and negatively predicted by introjected regulation (ß = –.22, p < .001) and amotivation (ß = –.49, p < .001). Boredom at work was negatively predicted by intrinsic motivation (ß = –.28, p < .005) and positively predicted by amotivation (ß = .68, p < .001). The Motivation for Teaching Scale in Secondary Education (Spanish acronym EME-ES, Escala de Motivación por la Enseñanza en Educación Secundaria) is discussed as a valid and reliable instrument. This is the first specific scale in the work context of secondary teachers that has integrated the five-factor structure together with their dedication and boredom at work.
To analyze the impact of the International Nosocomial Infection Control Consortium (INICC) Multidimensional Approach (IMA) and the INICC Surveillance Online System (ISOS) on central line-associated bloodstream infection (CLABSI) rates in 14 intensive care units (ICUs) in Argentina from January 2014 to April 2017.
This prospective, pre–post surveillance study of 3,940 ICU patients was conducted in 11 hospitals in 5 cities in Argentina. During our baseline evaluation, we performed outcome and process surveillance of CLABSI applying Centers for Disease Control and Prevention/National Health Safety Network (CDC/NHSN) definitions. During the intervention, we implemented the IMA through ISOS: (1) a bundle of infection prevention practice interventions, (2) education, (3) outcome surveillance, (4) process surveillance, (5) feedback on CLABSI rates and consequences, and (6) performance feedback of process surveillance. Bivariate and multivariate regression analyses were performed using a logistic regression model to estimate the effect of the intervention on the CLABSI rate.
During the baseline period, 5,118 CL days and 49 CLABSIs were recorded, for a rate of 9.6 CLABSIs per 1,000 central-line (CL) days. During the intervention, 15,659 CL days and 68 CLABSIs were recorded, for a rate of 4.1 CLABSIs per 1,000 CL days. The CLABSI rate was reduced by 57% (incidence density rate: 0.43; 95% confidence interval, 0.34–0.6; P<.001).
Implementing IMA through ISOS was associated with a significant reduction in the CLABSI rate in ICUs in Argentina.
The crystal structure of karibibite, Fe33+(As3+O2)4(As23+O5)(OH), from the Urucum mine (Minas Gerais, Brazil), was solved and refined from electron diffraction tomography data [R1 = 18.8% for F > 4σ(F)] and further confirmed by synchrotron X-ray diffraction and density functional theory (DFT) calculations. The mineral is orthorhombic, space group Pnma and unit-cell parameters (synchrotron X-ray diffraction) are a = 7.2558(3), b = 27.992(1), c = 6.5243 (3) Å, V = 1325.10(8) Å3, Z = 4. The crystal structure of karibibbite consists of bands of Fe3+O6 octahedra running along a framed by two chains of AsO3 trigonal pyramids at each side, and along c by As2O5 dimers above and below. Each band is composed of ribbons of three edge-sharing Fe3+O6 octahedra, apex-connected with other ribbons in order to form a kinked band running along a. The atoms As(2) and As(3), each showing trigonal pyramidal coordination by O, share the O(4) atom to form a dimer. In turn, dimers are connected by the O(3) atoms, defining a zig-zag chain of overall (As3+O2)n-n stoichiometry. Each ribbon of (Fe3+O6) octahedra is flanked on both edges by the (As3+O2)n-n chains. The simultaneous presence of arsenite chains and dimers is previously unknown in compounds with As3+. The lone-electron pairs (4s2) of the As(2) and As(3) atoms project into the interlayer located at y = 0 and y = ½, yielding probable weak interactions with the O atoms of the facing (AsO2) chain.
The DFT calculations show that the Fe atoms have maximum spin polarization, consistent with the Fe3+ state.
In (3+1) gravity it is well known that the vacuum plus a cosmological constant Λ, i.e., the (anti) de Sitter–Kottler (1918) solution, is a regular non-asymptotically flat solution (the scalar curvature is equal to 4Λ and all the invariants of the conformal Weyl tensor are zero.) On the other hand, Einstein–Maxwell electrovacuum asymptotically flat metrics endowed with timelike and spacelike symmetries do not allow for the existence of regular black hole solutions. In order to be able to derive regular (black hole) solutions one has to enlarge the class of electrodynamics to nonlinear ones; as an example, the regular solution by Ayón–Beato and García (1998), which is a solution to gravitational–nonlinear electromagnetic fields; the first examples belonging to this class are the Borde (1997) model and the Ayón–García regular charged static black hole.
In (2+1) gravity, in the vacuum case, all solutions are locally Minkowski (the Riemann tensor is zero); the extension to the vacuum plus cosmological constant allows for the existence of the static and the rotating anti-de Sitter regular black holes; see Bañados et al. (1992). The static (2+1)-charged black hole with cosmological constant is singular (when radial coordinate goes to zero the curvature and the Ricci square invariants blow up). Similarly, as in (3+1) gravity, one may search for regular solutions in (2+1) gravity incorporating nonlinear electromagnetic fields to which one imposes the weak energy conditions in order to have physically plausible matter-field distributions. One may look for regular solutions with nonlinear electromagnetic fields of the Born–Infeld type (Born and Infeld, 1934); Salazar et al. (1987); Salazar et. al (1984); Gibbons and Rasheed (1995); Fradkin and Tseytlin (1985); Deser and Gibbons (1998), and/or electrodynamics of wider spectra (Cataldo and García, 1999, 2000; Cataldo et al., 2000).
The Born–Infeld electrodynamics (Born and Infeld, 1934) is free from certain singularities appearing in the classical Maxwell electromagnetic field theory. Nonlinear electromagnetic Lagrangians, in particular the Born–Infeld Lagrangian, arise in open string theory (the low-energy effective action for an electromagnetic field is precisely the Born–Infeld action; see Fradkin and Tseytlin, 1985); string theory has emerged as the most promising candidate for the consistent quantization of gravity. In particular, the open string theory has Born–Infeld coupled vector fields, but it is not clear that this remains the case after compactification to a 3D space with negative cosmological constant Λ.
In this part of the book we deal with exact solutions to the Einstein topologically massive gravity equations. However, since the material to be included only represents twenty per cent of the whole book's subject matter, we prefer to present this content in the form of chapters devoted to a concise but, we hope, complete (in the range of the possibilities) exposition of the exact solutions in topologically massive gravity (TMG) in three dimensions in the case of vacuum in the presence of a cosmological constant Λ of both signs. Thus, this chapter has an introductory character, while the next three chapters deal with very specific families of the existing Petrov-type Cotton solutions in TMG.
The extension of the 3D Einstein gravity to other field theories to provide them with certain degrees of freedom (a massive spin 2 graviton) was proposed more than thirty-five years ago by Deser, Jackiw and Templeton; see Deser et al. (1982a): “Three-dimensional massive gauge theories,” which is known as the TMG. It includes a Chern–Simons term constructed from connections (Cotton tensor) with broken parity invariance; see also its extended version, with a detailed analysis, in Deser et al. (1982b). A cosmological constant was introduced in these three-dimensional theories by Deser (1984). The sign in front of the curvature scalar has been chosen opposite to the standard one of the Einstein gravity to yield, in the limit of the linearized theory, to the existence of a spin 2 graviton with positive energy. A modern treatment of these aspects in cosmological massive gravity appeared recently in Carlip et al. (2009).
As far as the determination of exact solutions to vacuum equations with a cosmological constant in TMG is concerned, through this long period, various classes of solutions have been reported apart from the trivial Minkowski flat spacetime, the de Sitter cosmology, and the BTZ black hole – conformally flat (zero Cotton tensor) solutions – for any value of the coupling mass parameter μ.