Does CUD measure interhemispheric transfer time? The allocation of attention influences the Poffenberger effect.

A simple reaction time (SRT) difference between responses to visual stimuli presented ipsilaterally and contralaterally to the responding hand, known as the Poffenberger effect or the crossed-uncrossed difference (CUD), has been commonly interpreted as a measure of interhemispheric transfer time (IHTT). However, the validity of this interpretation and the measure's reliability have been debated. The present study aimed at obtaining reliable evidence of the influence of spatial attention on the CUD, which would provide an argument against the classical interpretation of CUD. To meet the high statistical power requirements, over 100 thousand SRTs in total were collected from 12 participants. The task had three stimulus presentation conditions differing in the degree of stimulus location uncertainty: blocked (no uncertainty), randomized (full uncertainty), and mixed (25% uncertainty). The results showed robust effects of location uncertainty, proving spatial attention's contribution to the CUD. Further, we observed a strong visual-field asymmetry reflecting the right hemisphere specialization in target detection and spatial reorienting. Lastly, despite exceptional reliability of the component SRT measures, the CUD reliability was still too low to justify using this measure as an index of individual differences.

Climate change as a driver of food insecurity in the 2007 Lesotho-South Africa drought.

Climate-induced food production shocks, like droughts, can cause food shortages and price spikes, leading to food insecurity. In 2007, a synchronous crop failure in Lesotho and South Africa-Lesotho's sole trading partner-led to a period of severe food insecurity in Lesotho. Here, we use extreme event attribution to assess the role of climate change in exacerbating this drought, going on to evaluate sensitivity of synchronous crop failures to climate change and its implications for food security in Lesotho. Climate change was found to be a critical driver that led to the 2007 crisis in Lesotho, aggravating an ongoing decline in food production in the country. We show how a fragile agricultural system in combination with a large trade-dependency on a climatically connected trading partner can lead to a nonlinear response to climate change, which is essential information for building a climate-resilient food-supply system now and in the future.

On the role of anthropogenic climate change in the emerging food crisis in southern Africa in the 2019-2020 growing season.

Anthropogenic climate change likely influences the beginning of 2020 growing season's water deficit in parts of southern Africa, with severe consequences to food security.

Is laterality adaptive? Pitfalls in disentangling the laterality-performance relationship.

Unlike non-human animal studies that have progressively demonstrated the advantages of being asymmetrical at an individual, group and population level, human studies show a quite inconsistent picture. Specifically, it is hardly clear if and how the strength of lateralization that an individual is equipped with relates to their cognitive performance. While some of these inconsistencies can be attributed to procedural and conceptual differences, the issue is aggravated by the fact that the intrinsic mathematical interdependence of the measures of laterality and performance produces spurious correlations that can be mistaken for evidence of an adaptive advantage of asymmetry. Leask and Crow [Leask, S. J., & Crow, T. J. (1997), How far does the brain lateralize?: an unbiased method for determining the optimum degree of hemispheric specialization. Neuropsychologia, 35(10), 1381-1387] devised a method of overcoming this problem that has been subsequently used in several large-sample studies investigating the asymmetry-performance relationship. In our paper we show that the original Leask and Crow method and its later variants fall victim to inherent nonlinear dependencies and produce artifacts. By applying the Leask and Crow method to random data and with mathematical analysis, we demonstrate that what has been believed to describe the true asymmetry-performance relation in fact only reflects the idiosyncrasies of the method itself. We think that the approach taken by Leask in his later paper [Leask, S. (2003), Principal curve analysis avoids assumptions of dependence between measures of hand skill. Laterality, 8(4), 307-316. doi:10.1080/13576500342000004] might be preferable.

Anesthesia for Percutaneous Pulmonary Valve Implantation: A Case Series.

BACKGROUND: Twenty percent of patients born with congenital heart disease present with right ventricular outflow tract abnormalities. These patients require multiple surgical procedures in their lifetime. Transcatheter pulmonary valve replacement (TPVR) has become a viable alternative to conventional pulmonary valve and right ventricular outflow tract surgery in pediatric and adult populations. In this retrospective review, we analyze the perioperative management of adult patients who underwent TPVR in our center. METHODS: The study consisted of a chart review of patients who underwent TPVR at Toronto General Hospital between 2006 and 2015. Information about preoperative assessment, intraoperative anesthetic management, and intra- and postprocedural complications was collected. Two types of percutaneous valves have been used for a conduit or valve size between 16 and 28 mm. These procedures are done via the femoral, jugular, or subclavian vein under general anesthesia. RESULTS: Seventy-nine adults (17-68 years of age) who underwent elective TPVR procedures were included. General anesthesia was used in all cases. Defibrillation was necessary in 1 case, and bradycardia was spontaneously resolved in another 1. Eighty-five percent were successfully extubated at the end of the procedure. Five patients required intraoperative inotropic support. Three patients presented self-resolved hemoptysis. Mechanical ventilation for >24 hours was necessary in 3 cases, 2 of which also required concomitant inotropic support. Four failed deployments and 1 case of persistent conduit stenosis were reported. Three patients required reintubation. All patients were discharged home. CONCLUSIONS: Patients undergoing TPVR represent a complex and heterogeneous population. General anesthesia with endotracheal intubation is preferred. Setup for urgent lung isolation and cardiac defibrillation should be considered. Postoperative monitoring and intensive care setting are required. Anesthesiologists with cardiac anesthesia training are probably better suited to manage these patients.

Is saccade preparation required for inhibition of return (IOR)?

The effect of slower responses to validly than invalidly cued targets is known as inhibition of return (IOR). Opposing accounts of IOR have been proposed: one postulates a singular phenomenon explained by oculomotor mechanisms alone, while the other, more diverse account postulates both perceptual-cognitive and motor factors. In our research we considered the relation between motor programming and IOR. In an extended replication of an earlier study, using an eye abduction technique we restricted eye movement in the temporal half-space; this resulted in IOR attenuation in that area, compared to the unrestricted, nasal part of the visual field. Our results contradict the earlier result and demonstrate that IOR does depend on preparation of eye movement, as predicted by the oculomotor priming hypothesis.

Input, behaviour and distribution of multiple elements in abiotic matrices along a transect within the Okavango Delta, northern Botswana.

Wetlands fed by rivers can be a sink for elements depending on elemental concentrations, wetland hydrology, geochemistry, vegetation and climate. In the case of the Okavango Delta, northern Botswana, the outflow discharge is a small fraction (2-5%) of the inflow. This has strong potential consequences for the Delta, as it strongly affects element cycling and storage within the Delta. We estimated the inputs, behaviour and distribution of multiple elements along a longitudinal transect within the Okavango Delta, to show potential effects of retention mechanisms of different elements. High annual element input is rather attributed to discharge than to the concentration within the water, which is generally extremely low. We observed minimal enrichment of the elements within the water pathway along the transect from inflow to outlets, implying that element output is negligible. For most elements, we observed a high correlation between storage and sediment organic matter content. The organic matter content within the sediments was higher in the vegetated sediments than in non-vegetated sediments (factor âˆ¼ 10), and a similar trend was found for most elements. In conclusion, organic matter dominated in sediments from vegetated plots and thus plays an important role in retaining the elements within the sediments of the Delta. This finding has major implications for e.g. planning constructed wetlands for water purification or element retention especially in areas with high evapotranspiration.

Hemispheric asymmetry in the efficiency of attentional networks.

Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention. Participants (N=125) were tested with the Lateralized Attention Network Test (LANT) that allowed us to investigate the efficiency of the networks in both visual fields (VF). We found a LVF advantage when a target occurred in an unattended location, which seems to reflect right hemisphere superiority in control of the reorienting of attention. Furthermore, a LVF advantage in conflict resolution was observed, which may indicate hemispheric asymmetry of the executive network. No VF effect for alerting was found. The results, consistent with the common notion of general right hemisphere dominance for attention, provide a more detailed account of hemispheric asymmetries of the attentional networks than previous studies using the LANT task.

Transcatheter aortic valve implantation using transfemoral/transsubclavian or transapical approach: 30-day follow-up of the initial 30 patients.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a new method for the treatment of aortic stenosis (AS). AIM: To evaluate early results of TAVI using transfemoral/transsubclavian approach (TFA/TSA) or transapical approach (TAA) in patients with severe AS and high risk for surgical aortic valve replacement. METHODS: Between January 2009 and May 2010, 30 high-risk patients underwent TAVI. The primary treatment option was TFA, and TAA was used if contraindications to TFA were present; one patient underwent the procedure using TSA. Reasons for selecting TAA were as follows: small diameter (<7 mm) and/or severe calcification of the iliofemoral arteries, peripheral atherosclerosis, "porcelain" aorta and a horizontal course of the ascending aorta. Edwards-Sapien or CoreValve devices were used in all cases, and procedures were performed without the use of cardiopulmonary bypass in a cardiac catheterisation laboratory. RESULTS: Mean patient age was 82.46 ± 5.79 years, mean NYHA class was 3.23 ± 0.41, and predicted mean surgical mortality using logistic Euroscore was 29.18 ± 16.9% (22.72 ± 12.07% in the TFA/TSA group vs 34.6 ± 15.4% in the TAA group; p = 0.031). Eleven patients were treated using TAA. The valve was implanted successfully in 96% of patients. Inhospital mortality was 3.3%. Mean 30-day mortality was 6.6% in the entire cohort, 0% in the TFA/TSA group and 18% in the TAA group. There were no cases of periprocedural myocardial infarction (MI), cardiogenic shock, stroke/transient ischaemic attack, or need for cardiopulmonary resuscitation. One patient died suddenly three weeks after the procedure; except for this case, there were no major adverse cardiovascular events (MACCE: MI, cerebrovascular accident, re-do procedure) at 30-day follow-up. The TAVI was associated with a significant reduction in the mean maximal aortic gradient in both groups (from 99.6 ± 22.07 mm Hg to 21.83 ± 9.38 mm Hg post-procedure and to 23.25 ± 9.22 mm Hg at 30-day follow up), with no cases of severe aortic valve regurgitation. The NYHA class at 30 days improved from 3.23 ± 0.41 to 1.72 ± 0.52 (p = 0.03). CONCLUSIONS: Our results demonstrate lower 30-day complication rate and mortality in the TFA/TSA group. The availability of several techniques of valve implantation in the group of non-surgical patients with severe AS potentially broadens the patient population with indications for this treatment.

Percutaneous pulmonary valve implantation preceded by routine prestenting with a bare metal stent.

OBJECTIVES: To evaluate the effectiveness and safety of percutaneous pulmonary valve implantation (PPVI) with routine prestenting with a bare metal stent (BMS). BACKGROUND: PPVI is a relatively new method of treating patients with repaired congenital heart disease (CHD). Results of PPVI performed with routine prestenting have never been reported. METHODS: Consecutive patients who underwent PPVI for homograft dysfunction with prestenting with BMS were studied. The schedule of follow-up assessment comprised clinical evaluation, cardiovascular magnetic resonance, transthoracic echocardiography, and chest X-ray to screen for device integrity. RESULTS: PPVI was performed with no serious complications in all patients (n=10, mean age 26.8±4.0 years, 60% males). In nine patients with significant pulmonary stenosis, peak right ventricular outflow tract (RVOT) gradient was reduced from a mean of 80.6±22.7 to 38.8±10.4 mm Hg on the day following implantation (P=0.001). At 1-month and 6-month follow-ups, mean RVOT gradient was 34.0±9.8 and 32.0±12.2 mm Hg, respectively. In patients with significant pulmonary regurgitation, mean pulmonary regurgitation fraction decreased from 19%±6% to 2%±1% (P=0.0008). Relief of RVOT obstruction and restoration of pulmonary valve competence were associated with significant decrease in right ventricular (RV) end-diastolic and end-systolic volumes (125.5±48.6 to 109.2±42.9 mL/m2 ; P=0.002 and 68.4±41.5 vs. 50.9±40.6 mL/m2; P=0.001) as well as improvement in RV ejection fraction (48.8%±13.1% to 57.6%±14.4%; P=0.003) and New York Heart Association class (P=0.003). All patients completed 6-month follow-up. No stent fractures were observed. CONCLUSIONS: PPVI with routine prestenting with BMS is a safe and effective method of treatment in patients with repaired CHD.

[POL-PAVTI--Polish report on transcatheter pulmonary artery valve implantation of Melody-Medtronic prosthesis in the first 14 patients in Poland]. / Ogólnopolski raport POL-PAVTI z nieoperacyjnego wszczepienia biologicznej zastawki plucnej Melody-Medtronic u pierwszych w Polsce 14 chorych.

AIM: To assess the early results of the pulmonary artery valve transcatheter implantation (PAVTI) in pts included into POL-PAVTI registry. Detailed medical and economic analyses were performed. METHODS: Pulmonary artery valve implantation was performed in 14 pts (9 men), aged 16-31 (mean 24.6 +/- 4.8) years, with pulmonary homograft dysfunction after total repair of tetralogy of Fallot (4 pts), pulmonary atresia (2 pts), pulmonary stenosis (1 pt), common arterial trunk type I (1 pt), Ross procedure (3 pts) and TGA - Rastelli operation (3 pts). Eleven pts underwent in the past 2-5 surgical or/and catheter interventions. Indication for PAVTI was based on clinical evaluation and echocardiographic studies. Assessment of morphological and functional features of the right ventricle (RV) and homograft with the use of cardiac magnetic resonance (CMR) was performed in 10 cases. Pulmonary stenosis (max. pulmonary gradient 32-119, mean 72 +/- 28 mmHg) was observed in 13 pts and/or significant pulmonary regurgitation in 10 pts. The procedure was performed in general anesthesia. The deployment of a valved stent in the pulmonary valve position was preceded by a metal stent implantation. Results were evaluated by echocardiography two days after the procedure and one month later. Four patients were evaluated 6 months after procedure. RESULTS: Time of the procedure varied 60-190 (mean 127 +/- 35) min, time of fluoroscopy ranged 12-31 (mean 21 +/- 11) min. PAVTI was successfully performed in all pts without serious complications. Patients were discharged from the hospital 48-293 (mean 120 +/- 71) h after procedure. Significant reduction of pulmonary gradient after the procedure assessed by echocardiography was observed on the second day (20-60, mean 38 +/- 12 mmHg, p < 0.0001) and one month (19-52, mean 34 +/- 9 mmHg, p < 0.0001). Mild pulmonary regurgitation was observed in 2 pts. In 5 pts evaluated 6 months after procedure haemodynamic parameters were unchanged; no late complications were observed. Average cost of the procedure including a price of the valve (82 000 PLN) was 98 000 PLN. CONCLUSIONS: Pulmonary artery valve transvascular implantation is an effective and safe method of non-surgical treatment for patients with homograft dysfunction. Cost-effectiveness is approvable.

[Non-surgical, transcatheter pulmonary valve implantation - first experience]. / Nieoperacyjne wszczepienie zastawki plucnej - pierwsze doswiadczenia.

Transcatheter valve replacement has recently been introduced into clinical practice. We present our first experience with non-surgical, transcatheter pulmonary valve implantation in four patients (age 27-31 years, three females) with repaired congenital heart disease who required reintervention to the right ventricular outflow tract due to dysfunction of valve homograft. The Medtronic Melody Transcatheter Pulmonary Valve was successfully implanted in all four patients without complications, releasing the outflow obstruction, and normal function of the biological valve.

[Acute aortic dissection type A with concomitant myocardial infarction]. / Ostre rozwarstwienie aorty wstepujacej ze wspólistniejacym rozleglym zawalem serca - trudny problem kliniczny i diagnostyczny.

The authors describe a patient with acute aortic dissection type A complicated by left main coronary artery occlusion and acute myocardial infarction. The patient underwent urgent surgery, however, died 4 hours after operation.

[Coronary artery bypass grafting in a patient after percutaneous left main angioplasty with DES stent implantation]. / Pomostowanie tetnic wiencowych u chorej po uprzednio wykonanej przezskórnej angioplastyce i implantacji stentu do pnia lewej tetnicy wiencowej.

We present surgical treatment of acute coronary syndrome due to the left main stenosis in a patient in whom 6 months earlier percutaneous left main angioplasty with DES-stent implantation was performed. We discuss indications for percutaneous angioplasty and for coronary artery bypass grafting in patients with left main stenosis.

Risk of thromboembolic complications in patients with permanent atrial fibrillation undergoing cardioverter-defibrillator implantation.

BACKGROUND: Cardioversion of atrial fibrillation (AF) carries the risk of thromboembolic complications and, therefore, anticoagulation therapy is routinely administered before and after this procedure. In patients with permanent AF who undergo implantation of cardioverter-defibrillator (ICD), anticoagulants are usually withdrawn during the perioperative period. However, in some patients sinus rhythm may be restored during defibrillation threshold (DFT) testing which potentially may increase the risk of thromboembolic complications. AIM: To assess the frequency of sinus rhythm restoration during ICD implantation in patients with permanent AF and the rate of both thromboembolic events and local bleeding complications which may occur due to temporary withdrawal of anticoagulation therapy and its re-initiation early after the procedure. METHODS: Permanent AF was present in 23 (12%) of 193 patients selected for ICD implantation. All patients received prolonged oral anticoagulation according to the generally accepted standards. Anticoagulation therapy was stopped few days before the procedure and replaced by low molecular weight heparin which was administered up to 24 hours before ICD implantation and re-initiated 12-24 hours afterwards. RESULTS: During DFT testing sinus rhythm was restored in 5 (21.7%) patients with AF. Clinical and DFT characteristics were similar in those who were converted to sinus rhythm and those who remained in AF. No thromboembolic events were noted in either group. Local haematoma at the site of ICD implantation occurred in two (8%) patients. CONCLUSIONS: Sinus rhythm was restored in 21.7% of patients with permanent AF who underwent ICD implantation. Temporary withdrawal of anticoagulation therapy did not increase the risk of thromboembolic complications, however, its early re-initiation after implantation resulted in an increase in local bleeding complication rate.