Enhanced apoptotic index in hepatocytes, Kupffer cells, and inflammatory infiltrate showed positive correlation with hepatic lesion intensity, parasite load, and clinical status in naturally Leishmania-infected dogs.

It is unknown if Leishmania amastigote infections affect hepatocytes and Kupffer cell apoptosis, and the role played by apoptosis in liver lesions in leishmaniasis is still unclear. Clinically affected and subclinically infected dogs with leishmaniosis and uninfected controls were assessed. Parasite load, biochemical markers for evaluation of liver damage, morphometry (area, perimeter, number of inflammatory focus, major and minor diameters), apoptosis in hepatic tissue (hepatocytes, Kupffer cells, and inflammatory infiltrates) and cellularity in inflammatory foci were quantified. The parasite load in clinically affected dogs proved to be higher than in the other groups. All morphometric parameters (area, perimeter, number of inflammatory focus, major and minor diameters) from clinically affected were higher than the values found in the subclinically infected and uninfected control dogs. Only clinically affected dogs presented high levels of ALT, FA, GGT and cholesterol in serum. Strong positive correlation was observed between biochemical markers for evaluation of liver damage (ALT, FA, GGT and cholesterol) and hepatic apoptosis (hepatocytes, Kupffer cells, and inflammation). Clinically affected dogs showed a more intense hepatic lesion. Hepatocytes showed a higher rate of apoptosis in Leishmania-infected dogs than in uninfected control dogs. The Kupffer cell apoptotic index and apoptosis within the inflammatory infiltrates were higher in clinically affected dogs. The apoptotic index evaluated in hepatocytes, Kupffer cells, and inflammatory infiltrates showed a positive correlation with the intensity of the hepatic lesion, parasite load, and clinical status. Apoptotic cells also showed positive immunostaining for TUNEL, Bcl2, and Bax. Our data showed that hepatic apoptosis was related to the severity of liver damage, the progression of infection, and the parasite load in leishmaniasis. Apoptotic regulated cell recruitment modulated the inflammatory response and favored the survival and dissemination of parasites, depending on the clinical status of the Leishmania-infected dogs.

Resilience in deaf children: A comprehensive literature review and applications for school staff.

Resilience is a dynamic, multidimensional complex concept that implies risk and protective factors, adaptation, and success. Communication and language are often identified as barriers in deaf children's development. However, research linking deafness in childhood and resilience is scarce. The present comprehensive literature review aims to verify which are the predominant risk factors for this group, which protective factors may be identified and if significant differences have been found between deaf and hearing children regarding resilience. A systematic search, performed in seven databases, identified 11 articles published in peer-reviewed journals between 2000 and 2019 that met the criteria. Deaf children experience exposure to risk through obstacles in communication, language, and information failure. Consequently, differences between hearing and deaf children are related to more difficulties in emotion regulation and interpersonal relationships. Principal protective factors are a supportive family, school staff, and peers. Practical implications and recommendations for future research are provided.

Seroprevalence and risk factors for leptospirosis in cattle, sheep, and goats at consorted rearing from the State of Piauí, northeastern Brazil.

Leptospirosis is an endemic disease in Latin America, caused by pathogenic bacteria of the genus Leptospira. It is considered one of the main causes responsible for the negative economic impact on global livestock by causing reproductive problems. The research aimed to determine the prevalence of leptospirosis in cattle, sheep, and goats at consorted rearing in the micro-region of Teresina, Piauí state, northeastern Brazil, as well as to identify prevalent serovars and risk factors associated with seroprevalence. Serum samples were analyzed in 336 sheep, 292 goats, and 253 cattle using microscopic agglutination test (MAT). Overall, 378 samples were positive to MAT, with seroprevalence of 42.9%. The prevalences in cattle, sheep, and goats were 50.5, 40.5, and 34.6%, respectively. All herds presented at least one seropositive animal; the Hardjo/Wolffi serovar association was the most common in cattle and Icterohaemorrhagiae in goats and sheep. Beef production (OR = 4.9), cattle herd over 35 animals (OR = 4.0), feeding on pasture (OR = 6.4), weir and/or stream as water source (OR = 2.1), and no veterinary services (OR = 2.9) were risk factors for cattle infection. For sheep, intensive management system (OR = 5.3), suspended slatted facilities (OR = 2.2), more than 20 sheep in reproductive age (OR = 1.9), and absence of deworming (OR = 3.5) were the risk factors, while for goats, the identified risk factors were sheep herd over 52 animals (OR = 1.9) and no veterinary services (OR = 1.8). We conclude that the infection was spreading in consorted herds in this region. Thus, it would be interesting and important to conduct educative activities to farmers on the economic impacts of this disease and the need of preventive and control strategies mainly focused on sanitary measures and animal handling.

Leptospirosis seroprevalence and risk factors for sheep in Maranhão state, Brazil.

This study was conducted to determine leptospirosis seroprevalence in sheep and their spatial distribution as well as identify risk factors associated with seropositivity in sheep from 37 herds and 11 municipalities in the Presidente Dutra microregion, Maranhão state, Brazil. We analyzed 379 blood serum samples using a Microscopic Agglutination Test (MAT). The individual seroprevalence was 32%. Of the 37 herds studied, 30 (81%, 95% CI 69-94%) had at least one seropositive animal. In seven municipalities, we observed infection in 100% of the herds. The serovars recorded were Grippotyphosa (67%), Wollfi with Hardjo (9%), Bratislava (9%), Hardjo (5%), Icterohaemorrhagiae (5%), Pomona (2%), Castellonis (2%) and Copenhageni (0.8%). We concluded that the Leptospira spp. in sheep is widespread in the area of sheep farms in Maranhão state, and a risk factor is the animals' water source.

A new intervention to prevent social isolation in people with complex communication needs.

While implementing communication interventions, practitioners follow diverse theoretical models. Different conceptual orientations influence the way professionals embrace the subject of communication and its disorders. This research project explores the co-creation and validation of a new model and intervention program to analyze and improve communication between persons with Complex Communication Needs and their caregivers. The methodology incorporated a comprehensive narrative review, as foundation for the new model and intervention proposal. Succeeding this stage, the team implemented an online Delphi Panel to improve and validate these results, involving 17 international renowned experts. Following the Appropriateness Method, 25 indications were subject to scrutiny and rated as appropriate with minimal values of disagreement among the evaluators. Qualitative feedback was used to improve the research products. Quality assurance measures were taken to ensure quality and transparency of the results. A new conceptual framework of atypical interpersonal communication and intervention program result from the investigation. The new model is inspired by the Transactional model and principles of Dialogism. The intervention consists of consultations with caregivers, using video analysis and a dialogical methodology to enhance communication. The next research phase is to pilot-test the intervention program with clinicians supporting persons with disability at risk of social isolation.

Chronic thromboembolic pulmonary hypertension: A comprehensive review of pathogenesis, diagnosis, and treatment strategies.

Chronic thromboembolic pulmonary hypertension (CTEPH) is part of group 4 of the pulmonary hypertension (PH) classification and generally affects more than a third of patients referred to PH centers. It is a three-compartment disease involving proximal (lobar-to-segmental) and distal (subsegmental) pulmonary arteries that are obstructed by persistent fibrothrombotic material, and precapillary pulmonary arteries that can be affected as in pulmonary arterial hypertension. It is a rare complication of pulmonary embolism (PE), with an incidence of around 3% in PE survivors. The observed incidence of CTEPH in the general population is around six cases per million but could be three times higher than this, as estimated from PE incidence. However, a previous venous thromboembolic episode is not always documented. With advances in multimodality imaging and therapeutic management, survival for CTEPH has improved for both operable and inoperable patients. Advanced imaging with pulmonary angiography helps distinguish proximal from distal obstructive disease. However, right heart catheterization is of utmost importance to establish the diagnosis and hemodynamic severity of PH. The therapeutic strategy relies on a stepwise approach, starting with an operability assessment. Pulmonary endarterectomy (PEA), also known as pulmonary thromboendarterectomy, is the first-line treatment for operable patients. Growing experience and advances in surgical technique have enabled expansion of the distal limits of PEA and significant improvements in perioperative and mid- to long-term mortality. In patients who are inoperable or who have persistent/recurrent PH after PEA, medical therapy and/or balloon pulmonary angioplasty (BPA) are effective treatment options with favorable outcomes that are increasingly used. All treatment decisions should be made with a multidisciplinary team that includes a PEA surgeon, a BPA expert, and a chest radiologist.

E-learning is a burden for the deaf and hard of hearing.

When considering deaf and hard of hearing (DHH) population, research recognizes that fatigue due to communication challenges and multi-focal attention allocation is a significant concern. Given the putative heightened demands of distance learning on deaf and hard of hearing students, we investigate how an online environment might differently affect deaf and hard of hearing participants, compared to hearing participants, Portuguese Sign Language (PSL) users and non-users. Our findings show that the deaf and hard of hearing group present higher values in the post-task fatigue rates with significant differences from the hearing group (non-PSL users). Furthermore, our results revealed an association between post-task fatigue rates and lower performance scores for the deaf and hard of hearing group, and the gap is significantly bigger when compared with the hearing group (non-PSL users). We also found evidence for high levels of post-task fatigue and lower performance scores in the hearing group PSL users. These novel data contribute to the discussion concerning of the pros and cons of digital migration and help redesign more accessible and equitable methodologies and approaches, especially in the DHH educational field, ultimately supporting policymakers in redefining optimal learning strategies.

Unveiling teachers' beliefs on visual cognition and learning styles of deaf and hard of hearing students: A Portuguese-Swedish study.

Vision is considered a privileged sensory channel for deaf and hard of hearing (DHH) students to learn, and, naturally, they recognize themselves as visual learners. This assumption also seems widespread among schoolteachers, which led us to analyse the intersection between teachers' beliefs on deaf and hard of hearing students' academic achievement, visual skills, attentional difficulties, and the perceived importance of image display in class. An online survey was designed to analyse the beliefs of the schoolteachers about the deaf and hard of hearing students learning in educational settings from Portugal and Sweden. Participated 133 teachers, 70 Portuguese and 63 Swedish, from the preschool to the end of mandatory education (ages 3-18) with several years of experience. The content analysis and the computed SPSS statistical significance tests reveal that surveyed teachers believe that deaf and hard of hearing students have better visual skills when compared with their hearing peers yet show divergent beliefs about visual attentional processes. Within the teachers' perceptions on learning barriers to DHH students, the distractibility and cognitive effort factors were highlighted, among communicational difficulties in class. Conclusions about the prevalence of learning misconceptions in teachers from both countries analysed, corroborate previous studies on neuromyths in education, and bring novelty to Deaf Education field. The work of translation of scientific knowledge, teacher training updating, and partnership between researchers and educators are also urgently needed in special education.

Assessment of coconut water added to Numida meleagris egg yolk as cryoprotectant for goat semen.

Effects were assessed of the dilutants TRIS and ACP - 101c® with the addition of different guinea fowl (Numida meleagris) egg yolk concentrations. Fifteen ejaculates were collected from five goats of the Anglo Nubian breed. The ejaculates were pooled and then divided into 12 groups, two control groups (GC1 TRIS, with 2.5% Gallus gallus domesticus hen egg yolk GOGD), (GC2 Control Group ACP - 101c®, with the addition of 2.5% Gallus gallus domesticus hen egg yolk GOGD) and ten experimental groups (EG), containing TRIS and ACP added with different concentrations of egg yolk from guinea hen (Numida meleagris) (TRIS 2,5% GONM; TRIS 5% GONM; TRIS 10% GONM; TRIS 15% GONM; TRIS 20% GONM; ACP® 2,5% GONM; ACP® 5% GONM; ACP® 10% GONM; ACP® 15% GONM; ACP® 20% GONM). Then cryopreservation was carried out and the samples stored in liquid nitrogen (-196 °C). After seven days, the samples were thawed and assessed for spermatic kinetics, immunofluorescence and sperm morphology. Analysis of GOMN by the CASA system showed that the various parameters were similar to those of GOGD (P>0.05). The membrane integrity, mitochondrial potential and the acrosome were not influenced by the treatment (P>0.05) nor by the dilutant used for cryopreservation (P>0.05). The spermatic morphology was also preserved by the different GOGD and GONM concentrations in the ACP® and TRIS dilutants, with no statistically significant differences (P<0.05). It was concluded that Numida meleagris egg yolk, as external membrane cryoproctant added to the dilutants ACP-101c® and TRIS, improved goat semen quality.

Disentangling Pantomime From Early Sign in a New Sign Language: Window Into Language Evolution Research.

In this study, we aim to disentangle pantomime from early signs in a newly-born sign language: Sao Tome and Principe Sign Language. Our results show that within 2 years of their first contact with one another, a community of 100 participants interacting everyday was able to build a shared language. The growth of linguistic systematicity, which included a decrease in use of pantomime, reduction of the amplitude of signs and an increase in articulation economy, showcases a learning, and social interaction process that constitutes a continuum and not a cut-off system. The human cognitive system is endowed with mechanisms for symbolization that allow the process of arbitrariness to unfold and the expansion of linguistic complexity. Our study helps to clarify the role of pantomime in a new sign language and how this role might be linked with language itself, showing implications for language evolution research.

Chronic thromboembolic pulmonary hypertension: Initial experience of patients undergoing pulmonary thromboendarterectomy.

INTRODUCTION AND OBJECTIVES: Pulmonary endarterectomy (PEA) is a potentially curative procedure in patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study reports the initial experience of a Portuguese PH center with patients undergoing PEA at an international surgical reference center. METHODS: Prospective observational study of consecutive CTEPH patients followed at a national PH center, who underwent PEA at an international surgical reference center between October 2015 and March 2019. Clinical, functional, laboratory, imaging and hemodynamic parameters were obtained in the 12 months preceding the surgery and repeated between four and six months after PEA. RESULTS: 27 consecutive patients (59% female) with a median age of 60 (49-71) years underwent PEA. During a median follow-up of 34 (21-48) months, there was an improvement in functional class in all patients, with only one cardiac death. From a hemodynamic perspective, there was a reduction in mean pulmonary artery pressure from 48 (42-59) mmHg to 26 (22-38) mmHg, an increase in cardiac output from 3.3 (2.9-4.0) L/min to 4.9 (4.2-5.5) L/min and a reduction in pulmonary vascular resistance from 12.1 (7.2-15.5) uW to 3.5 (2.6-5,2) uW. During the follow-up, 44% (n=12) of patients had no PH criteria, 44% (n=12) had residual PH and 11% (n=3) had PH recurrence. There was a reduction of N-terminal pro-B-type natriureticpeptide from 868 (212-1730) pg/mL to 171 (98-382) pg/mL. Rright ventricular systolic function parameters revealed an improvement in longitudinal systolic excursion and peak velocity of the plane of the tricuspid ring from 14 (13-14) mm and 9 (8-10) cm/s to 17 (16-18) mm and 13 (11-15) cm/s, respectively. Of the 26 patients with preoperative right ventricular dysfunction, 85% (n=22) recovered. The proportion of patients on specific vasodilator therapy decreased from 93% to 44% (p<0.001) and the proportion of those requiring oxygen therapy decreased from 52% to 26% (p=0.003). The six-minute walk test distance increased by about 25% compared to the baseline and only eight patients had significant desaturation during the test. CONCLUSION: Pulmonary endarterectomy performed at an experienced high-volume center is a safe procedure with a very favorable medium-term impact on functional, hemodynamic and right ventricular function parameters in CTEPH patients with operable disease. It is possible for PH centers without PEA differentiation to refer patients safely and effectively to an international surgical center in which air transport is necessary.

Chronic thromboembolic pulmonary hypertension: initial experience of patients undergoing pulmonary thromboendarterectomy. / Hipertensão pulmonar tromboembólica crónica: experiência inicial de doentes submetidos a tromboendarterectomia pulmonar.

INTRODUCTION AND OBJECTIVES: Pulmonary endarterectomy (PEA) is a potentially curative procedure in patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study reports the initial experience of a Portuguese PH center with patients undergoing PEA at an international surgical reference center. METHODS: Prospective observational study of consecutive CTEPH patients followed at a national PH center, who underwent PEA at an international surgical reference center between October 2015 and March 2019. Clinical, functional, laboratory, imaging and hemodynamic parameters were obtained in the 12 months preceding the surgery and repeated between four and six months after PEA. RESULTS: 27 consecutive patients (59% female) with a median age of 60 (49-71) years underwent PEA. During a median follow-up of 34 (21-48) months, there was an improvement in functional class in all patients, with only one cardiac death. From a hemodynamic perspective, there was a reduction in mean pulmonary artery pressure from 48 (42-59) mmHg to 26 (22-38) mmHg, an increase in cardiac output from 3.3 (2.9-4.0) L/min to 4.9 (4.2-5.5) L/min and a reduction in pulmonary vascular resistance from 12.1 (7.2-15.5) uW to 3.5 (2.6-5, 2) uW. During the follow-up, 44% (n=12) of patients had no PH criteria, 44% (n=12) had residual PH and 11% (n = 3) had PH recurrence. There was a reduction of N-terminal pro-B-type natriureticpeptide from 868 (212-1730) pg/mL to 171 (98-382) pg/mL. Rright ventricular systolic function parameters revealed an improvement in longitudinal systolic excursion and peak velocity of the plane of the tricuspid ring from 14 (13-14) mm and 9 (8-10) cm/s to 17 (16-18) mm and 13 (11-15) cm/s, respectively. Of the 26 patients with preoperative right ventricular dysfunction, 85% (n=22) recovered. The proportion of patients on specific vasodilator therapy decreased from 93% to 44% (p<0.001) and the proportion of those requiring oxygen therapy decreased from 52% to 26% (p=0.003). The six-minute walk test distance increased by about 25% compared to the baseline and only eight patients had significant desaturation during the test. CONCLUSION: Pulmonary endarterectomy performed at an experienced high-volume center is a safe procedure with a very favorable medium-term impact on functional, hemodynamic and right ventricular function parameters in CTEPH patients with operable disease. It is possible for PH centers without PEA differentiation to refer patients safely and effectively to an international surgical center in which air transport is necessary.

Revisiting 'The influence of literacy in paraphasias of aphasic speakers'.

Literature suggests that illiterate subjects are unaware of the phonological structure of language. This fact may influence the characteristics of aphasic speech, namely the structure of paraphasias. A battery of tests was developed for this study to be used with aphasic subjects (literate and illiterate), in order to explore this topic in more detail. This article aims to present the experimental design and the results of this test battery composed of two sub-tests: (i) a naming test with words that belong to three distinct groups: high frequency simple words (HFSW), low frequency simple words (LFSW), and low frequency complex words (LFCW); and (ii) a word repetition test. The variables of literacy, frequency and word morphology, and their effect on the performance of aphasic groups, were correlated in this study. Morphology was the variable that exercised the greatest influence on the verbal production of the participants.

Development of microemulsion of tamsulosin and dutasteride for benign prostatic hyperplasia therapy.

Benign prostatic hyperplasia (BPH) is a condition characterized by a benign enlargement of the prostate that interferes with the normal flow of urine. This disease is treated with the oral administration of combination therapy comprising α-blockers (tamsulosin) and 5α-reductase inhibitors (dutasteride). However, these compounds have low bioavailability. Thus, transdermal microemulsions aimed at promoting permeation and efficient targeted drug delivery through the skin are used. The objectives of this study were to obtain microemulsions of the combined doses of dutasteride and tamsulosin and evaluate their anti-hyperplastic activity in vivo. A phase diagram (4:1) was obtained for the choice of microemulsions. The microemulsions were characterized in terms of the droplet size, rheology, pH, conductivity, refractive index, in vitro release profile, and antihyperplastic effect in vivo. A method for the simultaneous quantification of drugs was developed using UV-vis spectroscopy. The microemulsions had an average size less than 116 nm, an acidic pH and low viscosity. The conductivity ranged from 6.18 to 185.2 µS/cm. The in vitro release profile was sustained for 6 h. Microemulsions promoted the reduction in the size of testosterone-dependent organs (prostate and seminal vesicles). Transdermal formulations for the treatment of BPH were obtained as a therapeutic alternative to conventional treatments.

Sociodemographic and environmental analysis for the occurrence of anti-Leptospira antibodies in dogs of Teresina, Piauí, Brazil. / Análise sociodemográfica e ambiental para ocorrência de anticorpos antiLeptospira em cães de Teresina, Piauí, Brasil.

Leptospirosis is a worldwide zoonosis whose transmission is interlinked by multiple factors in the man-animal-ecosystem interface. This study aimed to evaluate the risk factors for the occurrence of anti-Leptospira antibodies in dogs in the capital Teresina (PI), and to determine their spatial distribution. Five hundred fifty-eight dog blood samples were submitted to the Microscopic Serum Agglutination (MSA) test. We applied semi-structured questionnaires to dog owners and obtained the area of residence for projection in geographical maps. Serum prevalence was 13.8%, in which the most common serovar was icterohaemorrhagiae, with 49.2%. Dogs with street access, failure to collect food bowl and low income of owners were risk factors. There was a higher number of seropositive dogs in the rainy season, with 87.1%, which is a probable risk factor for the occurrence of cases. The distribution of seropositive dogs was widely spread in the city, with predominance of cases in anthropized areas. These risk factors favor the occurrence of anti-Leptospira antibodies in dogs that are agent maintenance sources in the city and reinforce the need for epidemiological and environmental surveillance to prevent leptospirosis.

A leptospirose é uma zoonose mundial cuja transmissão está interligada por múltiplos fatores na interface homem-animal-ecossistema. Objetivou-se com este estudo avaliar os fatores de risco para a ocorrência de anticorpos antiLeptospira em cães na capital Teresina (PI), e determinar sua distribuição espacial. Amostras sanguíneas de 558 cães foram submetidas à prova de Soroaglutinação Microscópica (SAM). Aplicou-se questionários semiestruturados para os proprietários dos cães e obteve-se a localização geográfica da residência para a sua projeção em mapas geográficos. A soroprevalência foi de 13,8%, no qual o sorogrupo mais frequente foi o Icterohaemorrhagiae com 49,2%. Foram considerados fatores de risco os cães com acesso à rua, o não recolhimento da vasilha de alimento e a baixa renda dos proprietários. Foi observado maior número de cães soropositivos no período chuvoso com 87,1%, sendo um possível fator de risco para a ocorrência de casos. A distribuição dos cães soropositivos na cidade se apresentou de forma dispersa, com predominância dos casos em área antropizada. Esses fatores de risco favorecem a ocorrência de anticorpos antiLeptospiraem cães, os quais podem ser fontes de manutenção do agente na cidade e reforça a necessidade de vigilância epidemiológica e ambiental na prevenção da leptospirose.

[Rhodococcus equi pneumonia in an HIV+ patient: An uncommon association]. / Pneumonia por Rhodococcus equi em doente VIH (+): A propósito de uma associção rara.

The human infection by Rhodococcus equi, even in the presence of HIV infection, remains a rare disease. The authors present a case report of pneumonia, occurring in a HIV+ man. After identifying Pneumocystis jiroveci in the BAL, despite proper medication, the patient didn't improve. Another BAL was performed and a Rhodococcus equi isolated. The therapeutic regimen was changed according to this finding and the patient improved. The authors make a review of the literature, focusing on the rarity of this association and the high survival observed.

Early numerical cognition in deaf and hearing children: Closer than expected? / Cognición numérica temprana en niños sordos y oyentes: ¿más cercana de lo esperado?

Abstract Deaf students show a significant delay in their understanding of numeracy and measurement concepts as well as verbal problem solving. There is still no consensus about the origin of this delay but several studies have shown that deaf people show differences in basic numerical skills and executive function (EF), which could underlie the differences in the way they learn and develop their cognitive abilities. Children have the innate ability to estimate and compare numerosities without using language or numerical symbols. The ability to discriminate large numerosities depends on the approximate number system (ANS), a cognitive system believed to be governed by a neural circuit within the intraparietal sulcus. Researchers hypothesize that the ANS underlies the development of arithmetic and there is data supporting the contribution of the ANS for math achievements. Little is known about the approximate number system of deaf children at early ages. Deaf and hearing preschool children were compared in terms of specific cognitive functions shown to be important for success in mathematics. Executive functions and symbolic and nonsymbolic magnitude comparison abilities of 7 deaf children and 14 hearing children aged 4-7 years (M = 69.90 months, SD = 11.42), were compared. To do so, neuropsychological assessments for school-aged children were adapted into Portuguese Sign Language. Significant group differences were found in abstract counting as well as in symbolic and nonsymbolic magnitude comparisons. These findings suggest that deaf children are less competent in these early numeracy skills than are their hearing peers.

Resumen La cognición de los sordos ha sido objeto de numerosos estudios que buscan comprender cómo los niños y adultos sordos procesan la información. Dichos estudios han demostrado que las personas sordas muestran diferencias en las habilidades numéricas y la función ejecutiva (FE), lo que podría ser la base de las diferencias conocidas en la forma en que las personas sordas aprenden y desarrollan sus habilidades cognitivas. Se han encontrado diferencias entre estudiantes sordos y oyentes en varias áreas de razonamiento numérico, en matemática y en la eficiencia en el procesamiento de representaciones numéricas como la comparación de magnitud. En las tareas de comparación de magnitud, los resultados dependían de si se estaban haciendo comparaciones simbólicas (números arábigos) o no simbólicas (puntos). En un estudio, los niños sordos fueron más lentos que sus compañeros oyentes en las tareas de comparación de magnitud simbólica, pero no en las tareas no simbólicas. Sin embargo, en un estudio más reciente, también se encontraron diferencias en las tareas no simbólicas. Se considera que la capacidad para comparar y discriminar grandes numerosidades depende del sistema numérico aproximado (ANS, Approximate Number System), un sistema cognitivo que se cree está gobernado por un circuito neuronal dentro del surco intraparietal. Los investigadores plantean la hipótesis de que el ANS subyace en cierta medida al desarrollo de la aritmética. Hay algunos datos que apoyan esta hipótesis: por ejemplo, las diferencias individuales en la agudeza del ANS se correlacionan positivamente con las habilidades numéricas y los logros futuros en matemática. Por otro lado, se ha encontrado un deterioro en la agudeza del ANS en niños con discapacidades de aprendizaje matemático. En consecuencia, los investigadores han propuesto que el ANS contribuye a la aparición de conceptos numéricos que los niños requieren para la competencia básica en el conteo y las comparaciones de magnitud simbólica. Otros han sugerido que la asociación entre la agudeza en la comparación de magnitud no simbólica y el rendimiento en matemática está moderada por factores de dominio general como las funciones ejecutivas (FE), en particular el control inhibitorio. En general, no está claro si existen diferencias en la agudeza de comparación de magnitud simbólica y no simbólica en niños sordos más pequeños y en qué medida se relacionan con las FE. El estudio actual examina la agudeza de las representaciones numéricas simbólicas y no simbólicas en niños sordos en edad preescolar e investiga la posible influencia del funcionamiento ejecutivo en estas habilidades matemáticas básicas. Se recolectaron datos de 21 niños portugueses del área de Lisboa, siete de los cuales eran sordos congénitamente y 14 tenían audición normal; los niños tenían entre 4 y 7 años de edad (M = 69.9 meses, DT = 11.42). Se seleccionaron tareas para medir lo siguiente: (a) FE, (b) memoria de trabajo, (c) lenguaje y (d) habilidades numéricas tempranas. Se empleó la tarea Shape School Task para evaluar FE. Se administró la versión portuguesa de la tarea de tapping de bloques de Corsi para evaluar la amplitud visuoespacial. Se desarrolló una tarea de comparación de puntos para examinar la capacidad de los niños de decidir instantáneamente cuál de las dos matrices de puntos es más grande utilizando el software Panamath. Se utilizaron dos tareas para evaluar la capacidad de los niños para producir palabras numéricas en un contexto cardinal y el Numeracy Screener para medir su capacidad para comprender la magnitud numérica simbólica. Los resultados indicaron que los niños sordos mostraron retrasos en las capacidades de comparación de magnitud simbólica y no simbólica. En las FE solo se encontraron diferencias en una tarea que implicaba una combinación de conmutación e inhibición; por lo demás, su función ejecutiva era comparable a la de los niños no sordos.