During sensory processing, cortical areas continuously exchange information in different directions along the hierarchy. The functional role of such interactions, however, has been the subject of ...various proposals. Here, we investigate the role of bottom‐up and top‐down interactions in processing stimulus structure and their relation to expected events. Applying multivariate autoregressive methods to local field potentials recorded in alert cats, we quantify directed interactions between primary (A17/18) and higher (A21) visual areas. A trial‐by‐trial analysis yields the following findings. To assess the role of interareal interactions in processing stimulus structure, we recorded in naïve animals during stimulation with natural movies and pink noise stimuli. The overall interactions decrease compared with baseline for both stimuli. To investigate whether forthcoming events modulate interactions, we recorded in trained animals viewing two stimuli, one of which had been associated with a reward. Several results support such modulations. First, the interactions increase compared with baseline and this increase is not observed in a context where food was not delivered. Second, these stimuli have a differential effect on top‐down and bottom‐up components. This difference is emphasized during the stimulus presentation and is maximal shortly before the possible reward. Furthermore, a spectral decomposition of the interactions shows that this asymmetry is most dominant in the gamma frequency range. Concluding, these results support the notion that interareal interactions are more related to an expectancy state rather than to processing of stimulus structure.
Traumatic brain injury according to the World Health Organization estimates that by 2020 will be the third leading cause of morbidity and mortality worldwide. Intracranial hypertension refractory to ...medical management is the cause of increased mortality in neurotrauma. There are various measures to control intracranial hypertension, including surgical. Decompressive craniectomy has been routinely used to treat intracranial hypertension secondary to cerebral infarction, subarachnoid hemorrhage, intracerebral hemorrhage and trauma. We review the literature to describe the mechanisms, types and indications for this procedure.
Generally, the phosphoric acid-activated systems use aluminosilicates as raw material (e.g., metakaolin); and the addition of alkali metals (e.g., Mg or Ca) contributes to obtain best properties. ...Volcanic ash (Va) is an aluminosilicate globally available and contain these metal oxides, which makes it a suitable raw material to produce acid-activated cements. The research on the production of this type of cements using Va is relatively recent. The knowledge on some parameters that influence the activation process under acid conditions of Va can be of great value as a viable alternative to its industrial application in the foreseeable future. This study examines the reactivity of four samples of volcanic ashes with different chemical composition in phosphoric acid at ambient temperature (25 °C). Two concentrations of phosphoric acid were used (41.1% and 51.2% P2O5 by mass). The main parameter used in this study is the molar ratio R expressed as the relation (MgO + CaO)/P2O5. Properties such as setting time, paste temperature in fresh state and compressive strength at 28 days of curing were evaluated. The final products obtained via acid activation of the volcanic ashes were studied using the XRD and FTIR techniques. The results showed that the initial and final setting time and the compressive strength increases with the increase of the molar ratio R of the mix when the proportion of P2O5 is constant. This coincides with the decrease in the temperature of the pastes. The highest compressive strength at 28 days of curing (81.3 MPa) was obtained with a molar ratio R = 4.2 and 41.1% P2O5 using a volcanic ash with high calcium and magnesium content (13.1% and 9.9% respectively). This volcanic ash when is activated with phosphoric acid of 51.2% P2O5 (R = 3.0) reported lower strength (40%) and a significant increase in the setting time. The results obtained showed that the CaO and MgO content in the volcanic ash and the acid concentration used as activator are parameters that affect the final properties of the acid-activated cements. Also, the presence of amorphous phase hindered the reactivity. Based on the results, the volcanic ashes may be considered precursors in the production of phosphoric acid-activated cements for construction purposes.
•Phosphoric acid-activated cements based on four different volcanic ashes were obtained.•CaO and MgO content in volcanic ash promotes their phosphoric acid-activation at room temperature.•The acid concentration (%P2O5) used as activator affect the final properties of cements.•Molar ratio R= (MgO + CaO)/P2O5 promotes the compressive strength of cements.•The highest compressive strength at 28 days (room temperature) was 81.3 MPa.
This study investigates how perceived unfair treatment, towards self and observed towards others due to ethnicity, is associated with periodontitis among diverse Hispanic/Latino adults, accounting ...for sociodemographic, health behavior, and acculturation factors. Baseline (2008–2011) dental and survey data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a multicenter epidemiologic study, were analyzed (N = 12,750). Crude and adjusted prevalence ratios and confidence limits were estimated. Half (49%) reported never being treated unfairly, while 41% reported they were sometimes, and 10% reported it often/always. One third (32%) never saw others treated unfairly, while 42% reported it sometimes, and 26% reported it often/always. In the final fully adjusted model, the prevalence of periodontitis was higher among adults who were as follows: non-Dominican, older, male, had a past year dental visit, current and former smokers, and among those who observed unfair treatment towards others. Lower prevalence was associated with higher income, higher educational attainment, less than full-time employment, reporting experiencing unfair treatment, higher acculturation scores, and having health insurance. Perceived unfair treatment towards self was negatively associated with periodontitis prevalence, while observed unfair treatment towards others was positively associated with the outcome among diverse Hispanics/Latinos. The associations between unfair treatment and periodontitis warrant further exploration.
Metal content, Metallotionein and physiological condition (RNA/DNA ratio) were analyzed in Cachama, Colossoma macropomum from the Orinoco River. Juvenile samples were dissected and one gram of white ...muscle gills, kidney and liver was taken. Cu, Cd, Pb, Ni and Fe were analyzed by atomic absorption spectrophotometer using TORT and LUTSI as reference material. Metallothioneins were determined with Ellman´s reagent and RNA/DNA ratio was analyzed by fluorometric method. Results showed that Cd, Cu, Ni, Fe, and Pb levels were significantly higher in liver than muscle. There was no difference statistically between Mts concentrations in liver, kidney and gills; muscle showed the lowest Mts concentrations. Multivariate analysis ACP determined relationship between Mts-L and Cu and Mts-G and Cd. The Mts in muscle was related with Pb and Cd. There was no association between physiological condition and metals concentrations, however, the RNA/ DNA showed relationship with Mts-M and Mts-L
Many patients are currently unable to access psychological treatments for post-traumatic stress disorder (PTSD), and it is unclear which types of therapist-assisted internet-based treatments work ...best. We aimed to investigate whether a novel internet-delivered cognitive therapy for PTSD (iCT-PTSD), which implements all procedures of a first-line, trauma-focused intervention recommended by the UK National Institute for Health and Care Excellence (NICE) for PTSD, is superior to internet-delivered stress management therapy for PTSD (iStress-PTSD), a comprehensive cognitive behavioural treatment programme focusing on a wide range of coping skills.
We did a single-blind, randomised controlled trial in three locations in the UK. Participants (≥18 years) were recruited from UK National Health Service (NHS) Improving Access to Psychological Therapies (IAPT) services or by self-referral and met DSM-5 criteria for PTSD to single or multiple events. Participants were randomly allocated by a computer programme (3:3:1) to iCT-PTSD, iStress-PTSD, or a 3-month waiting list with usual NHS care, after which patients who still met PTSD criteria were randomly allocated (1:1) to iCT-PTSD or iStress-PTSD. Randomisation was stratified by location, duration of PTSD (<18 months or ≥18 months), and severity of PTSD symptoms (high vs low). iCT-PTSD and iStress-PTSD were delivered online with therapist support by messages and short weekly phone calls over the first 12 weeks (weekly treatment phase), and three phone calls over the next 3 months (booster phase). The primary outcome was the severity of PTSD symptoms at 13 weeks after random assignment, measured by self-report on the PTSD Checklist for DSM-5 (PCL-5), and analysed by intention-to-treat. Safety was assessed in all participants who started treatment. Process analyses investigated acceptability and compliance with treatment, and candidate moderators and mediators of outcome. The trial was prospectively registered with the ISRCTN registry, ISRCTN16806208.
Of the 217 participants, 158 (73%) self-reported as female, 57 (26%) as male, and two (1%) as other; 170 (78%) were White British, 20 (9%) were other White, six (3%) were Asian, ten (5%) were Black, eight (4%) had a mixed ethnic background, and three (1%) had other ethnic backgrounds. Mean age was 36·36 years (SD 12·11; range 18–71 years). 52 (24%) participants met self-reported criteria for ICD-11 complex PTSD. Fewer than 10% of participants dropped out of each treatment group. iCT-PTSD was superior to iStress-PTSD in reducing PTSD symptoms, showing an adjusted difference on the PCL-5 of –4·92 (95% CI –8·92 to –0·92; p=0·016; standardised effect size d=0·38 0·07 to 0·69) for immediate allocations and –5·82 (–9·59 to –2·04; p=0·0027; d=0·44 0·15 to 0·72) for all treatment allocations. Both treatments were superior to the waiting list for PCL-5 at 13 weeks (d=1·67 1·23 to 2·10 for iCT-PTSD and 1·29 0·85 to 1·72 for iStress-PTSD). The advantages in outcome for iCT-PTSD were greater for participants with high dissociation or complex PTSD symptoms, and mediation analyses showed both treatments worked by changing negative meanings of the trauma, unhelpful coping, and flashback memories. No serious adverse events were reported.
Trauma-focused iCT-PTSD is effective and acceptable to patients with PTSD, and superior to a non-trauma-focused cognitive behavioural stress management therapy, suggesting that iCT-PTSD is an effective way of delivering the contents of CT-PTSD, one of the NICE-recommended first-line treatments for PTSD, while reducing therapist time compared with face-to-face therapy.
Wellcome Trust, UK National Institute for Health and Care Research Oxford Health Biomedical Research Centre.
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