Why is math anxiety usually related to less efficient math processing? According to attentional control theory, anxiety leads to reduced attentional control, which often entails a greater investment ...of resources (e.g., more time or effort) to carry out a cognitive task. The executive functions mainly affected by anxiety are inhibition and shifting. Previous studies suggest that math anxiety may impair the inhibitory function. In the present study, the relationship between math anxiety and shifting efficiency when switching between two‐digit additions and subtractions was examined. Twenty highly math‐anxious and 20 low math‐anxious individuals participated in an event‐related potential (ERP) transition‐cueing experiment. Math anxiety was expected to delay the shifting process, leading to a larger switch cost in response time and no centroparietal cue‐locked switch‐specific positivity registered in the electroencephalogram during the cue‐target interval. Highly math‐anxious individuals showed a larger switch cost than their low math‐anxious peers. Asymmetrical switch effects between operations in response time were found in both groups, which might be due to larger sequential difficulty effects after subtractions than after additions. The cue‐locked switch‐specific positivity was present only in the low math‐anxious group. The present results suggest that highly math‐anxious individuals take longer to shift task sets. Additionally, the highly math‐anxious group showed a more positive frontal P2 after the cue that announced a switch to subtraction, probably indicating stronger attentional capture by this cue, because the most threatening condition is anticipated. Taken together, these data suggest that math anxiety also impairs attentional control when switching between arithmetic tasks.
In an event‐related potential (ERP) task‐switching experiment, highly math‐anxious individuals showed higher switch cost and absence of the cue‐locked late switch positivity. This provides the first evidence that math anxiety is associated with reduced shifting efficiency when switching between additions and subtractions, as predicted by attentional control theory. The impairment of this executive function may help to explain the difficulties that highly math‐anxious individuals experience when performing math.
This study uses event-related brain potentials (ERPs) to investigate the electrophysiological correlates of numeric conflict monitoring in math-anxious individuals, by analyzing whether math anxiety ...is related to abnormal processing in early conflict detection (as shown by the N450 component) and/or in a later, response-related stage of processing (as shown by the conflict sustained potential; Conflict-SP). Conflict adaptation effects were also studied by analyzing the effect of the previous trial's congruence in current interference. To this end, 17 low math-anxious (LMA) and 17 high math-anxious (HMA) individuals were presented with a numerical Stroop task. Groups were extreme in math anxiety but did not differ in trait or state anxiety or in simple math ability. The interference effect of the current trial (incongruent-congruent) and the interference effect preceded by congruence and by incongruity were analyzed both for behavioral measures and for ERPs. A greater interference effect was found for response times in the HMA group than in the LMA one. Regarding ERPs, the LMA group showed a greater N450 component for the interference effect preceded by congruence than when preceded by incongruity, while the HMA group showed greater Conflict-SP amplitude for the interference effect preceded by congruence than when preceded by incongruity. Our study showed that the electrophysiological correlates of numeric interference in HMA individuals comprise the absence of a conflict adaptation effect in the first stage of conflict processing (N450) and an abnormal subsequent up-regulation of cognitive control in order to overcome the conflict (Conflict-SP). More concretely, our study shows that math anxiety is related to a reactive and compensatory recruitment of control resources that is implemented only when previously exposed to a stimuli presenting conflicting information.
Radiotherapy (RT) is a modality of oncologic treatment that can be used to treat approximately 50% of all cancer patients either alone or in combination with other treatment modalities such as ...surgery, chemotherapy, immunotherapy, and therapeutic targeting. Despite the technological advances in RT, which allow a more precise delivery of radiation while progressively minimizing the impact on normal tissues, issues like radioresistance and tumor recurrence remain important challenges. Tumor heterogeneity is responsible for the variation in the radiation response of the different tumor subpopulations. A main factor related to radioresistance is the presence of cancer stem cells (CSC) inside tumors, which are responsible for metastases, relapses, RT failure, and a poor prognosis in cancer patients. The plasticity of CSCs, a process highly dependent on the epithelial-mesenchymal transition (EMT) and associated to cell dedifferentiation, complicates the identification and eradication of CSCs and it might be involved in disease relapse and progression after irradiation. The tumor microenvironment and the interactions of CSCs with their niches also play an important role in the response to RT. This review provides a deep insight into the characteristics and radioresistance mechanisms of CSCs and into the role of CSCs and tumor microenvironment in both the primary tumor and metastasis in response to radiation, and the radiobiological principles related to the CSC response to RT. Finally, we summarize the major advances and clinical trials on the development of CSC-based therapies combined with RT to overcome radioresistance. A better understanding of the potential therapeutic targets for CSC radiosensitization will provide safer and more efficient combination strategies, which in turn will improve the live expectancy and curability of cancer patients.
•The YBT test reliably detects dynamic balance deficits in people with ankle surgery.•Non-operated leg scores can be used as reference values for balance restoration.•Bilateral YBT differences >3.3 % ...can be considered as clinically relevant.•Balance restoration should also focus on improving hip weakness.
Ankle fractures are among the most common traumatic fractures and have a great socio-economic impact. Consequences of an ankle fracture requiring surgical treatment (e.g. pain, reduced ankle range of motion (ROM), muscle weakness, etc.) lead to balance deterioration, which has a profound impact on activities of daily living. However, to the best of the authors' knowledge, no reliable clinical tests are available to monitor balance in patients after ankle surgery.
To quantify single-leg dynamic balance in patients with bimalleolar ankle fracture through the Y-Balance test (YBT). The second objective was to analyze the impact of ankle dorsiflexion ROM and hip strength on balance to optimize balance rehabilitation programs.
Cross-sectional study.
22 participants, who had undergone surgery after bimalleolar ankle fractures, were assessed for ankle ROM, hip strength, and dynamic balance six-months after the surgical intervention. The within-session reliability of YBT was calculated through the intraclass correlation coefficient (ICC) and the standard error of measurement (SEM). Student's t-tests were used to assess leg differences. A multiple regression analysis was performed to evaluate the role of ankle dorsiflexion ROM and hip abductor and adductor strength in predicting balance performance.
YBT showed high-to-excellent within-session relative reliability (Healthy leg: 0.85 ≤ ICC≤0.96; Operated leg: 0.84 ≤ ICC≤0.96). SEM values were below 3.3 %. The operated leg showed significant lower YBT scores for anterior reach direction (−9.0 %; g=−0.70) and composite score (-4.5 %; g=−0.34). Multiple regression analysis showed that both, ankle dorsiflexion and hip abductor and adductor strength explained 66 % of the variance in the YBT anterior direction of the operated leg.
The YBT is a reliable tool that allows the quantification of single-leg dynamic balance impairments from 6-months after surgery in patients with bimalleolar ankle fracture. Between-leg YBT differences in the anterior direction can be used as reference scores (3.3 %) for balance restoration. Balance rehabilitation programs should focus on improving ankle functionality and reducing hip muscle weakness with specific hip strength exercises and balance exercises with similar demands to the reaching tasks of the YBT to promote a faster recovery.
Background
It is not clear whether clinical practice guidelines (CPGs) and consensus statements (CSs) are adequately promoting shared decision making (SDM).
Objective
To evaluate the recommendations ...about SDM in CPGs and CSs concerning breast cancer (BC) treatment.
Search strategy
Following protocol registration (Prospero no.: CRD42018106643), CPGs and CSs on BC treatment were identified, without language restrictions, through systematic search of bibliographic databases (MEDLINE, EMBASE, Web of Science, Scopus, CDSR) and online sources (12 guideline databases and 51 professional society websites) from January 2010 to December 2019.
Inclusion criteria
CPGs and CSs on BC treatment were selected whether published in a journal or in an online document.
Data extraction and synthesis
A 31‐item SDM quality assessment tool was developed and used to extract data in duplicate.
Main results
There were 167 relevant CPGs (139) and CSs (28); SDM was reported in only 40% of the studies. SDM was reported more often in recent publications after 2015 (42/101 (41.6 %) vs 46/66 (69.7 %), P = .0003) but less often in medical journal publications (44/101 (43.5 %) vs 17/66 (25.7 %), P = .009). In CPGs and CSs with SDM, only 8/66 (12%) met one‐fifth (6 of 31) of the quality items; only 14/66 (8%) provided clear and precise SDM recommendations.
Discussion and conclusions
SDM descriptions and recommendations in CPGs and CSs concerning BC treatment need improvement. SDM was more frequently reported in CPGs and CSs in recent years, but surprisingly it was less often covered in medical journals, a feature that needs attention.
•Math anxiety is related to a less precise representation of numerical magnitude.•Both size and distance effects are larger in high math-anxious individuals.•The size effect elicits a similar ERP ...component to that elicited by the distance effect.•A larger ERP distance effect is elicited in high math-anxious individuals.
Numerical comparison tasks are widely used to study the mental representation of numerical magnitude. In study, event-related brain potentials (ERPs) were recorded while 26 high math-anxious (HMA) and 27 low math-anxious (LMA) individuals were presented with pairs of single-digit Arabic numbers and were asked to decide which one had the larger numerical magnitude. The size of the numbers and the distance between them were manipulated in order to study the size and the distance effects. The results showed that both distance and size effects were larger for the HMA group. As for ERPs, results showed that the ERP distance effect had larger amplitude for both the size and distance effects in the HMA group than among their LMA counterparts. Since this component has been taken as a marker of the processing of numerical magnitude, this result suggests that HMA individuals have a less precise representation of numerical magnitude.
We examined the relationships between math anxiety, perfectionism and academic achievement in undergraduates enrolled in a course with high mathematical content. Participants were 251 students who ...completed math anxiety and perfectionism questionnaires, and whose academic achievement was measured via a multiple-choice examination. The number of hits, errors and unanswered questions on this examination were analyzed to explore the possible influence of math anxiety and perfectionism on students' performance. Results showed that highly math-anxious (HMA) students were more perfectionist than their low math-anxious (LMA) peers, insofar as they were more concerned about making mistakes and had more doubts about their own actions. The HMA group also obtained worse grades than did their LMA counterparts, although this was because they left more questions unanswered, not because they made more mistakes. Analysis of the relationship between math anxiety and the number of unanswered questions revealed that concern over errors and doubts about actions played a mediating role in this relationship. In conclusion, HMA students' fear of making mistakes and doubts about their own actions are important factors influencing their performance in multiple-choice tests.
Propagation of light in a metamaterial medium which mimics curved spacetime and acts like a black hole is studied. We show that for a particular type of spacetimes and wave polarization, the time ...dilation appears as dielectric permittivity, while the spatial curvature manifests as magnetic permeability. The optical analogue to the relativistic Hamiltonian which determines the ray paths (null geodesics) in the anisotropic metamaterial is obtained. By applying the formalism to the Schwarzschild metric, we compare the ray paths with full-wave simulations in the equivalent optical medium.
•Optical analogue to the static anisotropic spacetime metric obeying rotational symmetries is studied.•Explicit expressions for the permittivity and permeability tensors are obtained.•Explicit expression for the optical Hamiltonian is found.•Ray paths are compared with full-wave simulations for the Schwarzschild metric in anisotropic and isotropic cases.
Head and neck cancer (HNC) is among the ten most frequent tumours, with 5-year survival rates varying from 30% to 70% depending on the stage and location of the tumour. HNC is traditionally known as ...head and neck squamous cell carcinoma (HNSCC), since 90% arises from epithelial cells. Metastasis remains a major cause of mortality in patients with HNSCC. HNSCC patients with metastatic disease have an extremely poor prognosis with a survival rate of less than a year. Matrix metalloproteinases (MMPs) have been described as biomarkers that promote cell migration and invasion. Radiotherapy is widely used to treat HNSCC, being a determining factor in the alteration of the tumour's biology and microenvironment. This review focuses on analysing the current state of the scientific literature on this topic. Although few studies have focused on the role of these proteinases in HNC, some authors have concluded that radiotherapy alters the behaviour of MMPs and tissue inhibitors of metalloproteinases (TIMPs). Therefore, more research is needed to understand the roles played by MMPs and their inhibitors (TIMPs) as prognostic biomarkers in patients with HNC and their involvement in the response to radiotherapy.
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