A heuristic-based approach for assessing usability in electric powered wheelchairs: A preliminary investigation

Objective: An important issue related to electric powered wheelchair (EPW) is usability. Recent studies did not use heuristic evaluation and did not consider users’ and developers’ participation in the usability evaluation process of the EPW, especially when it has to be driven using alternative commands. Thus, this study investigates the use of heuristics to evaluate the usability of EPW driven by alternative commands, considering the opinion of users and assistive technology (AT) development professionals.MethodsThe study was carried out with 54 participants: 28 EPW users (Group I) and 26 AT developers (Group II). We built a set of 25 heuristics that affects EPW usability. Participants rated each of the 25 heuristics according to their importance for the usability of EPW using the five-point Likert scale. We used the R Software to perform the Wilcoxon Mann–Whitney test as a statistical comparisons test between Group I and II.ResultsThe results showed a statistically significant difference (p<0.05) between Group I and II in the evaluation of 16 heuristics. We identified an important set of heuristics that could help evaluate and improve the usability of EPW.ConclusionThe findings highlighted the importance of considering users’ and developers’ points of view in developing an EPW and its evaluation criteria. It could help the design of the device match the user's needs and expectations. The set of heuristics in this study can be adapted to evaluate other devices’ usability using the heuristic evaluation approach. (AU)

Objetivo: La usabilidad es una cuestión importante relacionada con las sillas de ruedas eléctricas (SRE). Los estudios recientes no han utilizado evaluaciones heurísticas ni han contemplado la participación de los usuarios y desarrolladores en el proceso de evaluación de dichas sillas, especialmente cuando deben conducirse utilizando comandos alternativos. Por ello, este estudio investiga el uso de la heurística para evaluar la usabilidad de las SRE impulsadas por comandos alternativos, considerando la opinión de los usuarios y los profesionales del desarrollo de la tecnología asistencial (TA).MétodosEl estudio se realizó con 54 participantes: 28 usuarios de SRE (Grupo I) y 26 desarrolladores de TA (Grupo II). Construimos un conjunto de 25 heurísticas que afectan a la usabilidad de las SRE. Los sujetos calificaron cada una de las 25 heurísticas de acuerdo con su importancia para la usabilidad de las SRE utilizando la escala de Likert de cinco puntos. Utilizamos el software R para realizar la prueba de Wilcoxon-Mann-Whitney como prueba de comparación estadística entre los Grupos I y II.ResultadosLos resultados reflejaron una diferencia estadística significativa (p < 0,05) entre los Grupos I y II en la evaluación de las 16 heurísticas. Identificamos un conjunto importante de heurísticas que podrían ayudar a evaluar y mejorar la usabilidad de las SRE.ConclusiónLos hallazgos subrayaron la importancia de estimar los puntos de vista de los usuarios y desarrolladores a la hora de desarrollar una SRE, así como sus criterios de evaluación. Estos podrían contribuir a que el diseño del dispositivo coincidiera con las necesidades y expectativas de los usuarios. El conjunto de heurísticas de este estudio puede adaptarse, para evaluar la usabilidad de otros dispositivos, utilizando el enfoque de evaluación heurística. (AU)

A heuristic-based approach for assessing usability in electric powered wheelchairs: A preliminary investigation.

OBJECTIVE: An important issue related to electric powered wheelchair (EPW) is usability. Recent studies did not use heuristic evaluation and did not consider users' and developers' participation in the usability evaluation process of the EPW, especially when it has to be driven using alternative commands. Thus, this study investigates the use of heuristics to evaluate the usability of EPW driven by alternative commands, considering the opinion of users and assistive technology (AT) development professionals. METHODS: The study was carried out with 54 participants: 28 EPW users (Group I) and 26 AT developers (Group II). We built a set of 25 heuristics that affects EPW usability. Participants rated each of the 25 heuristics according to their importance for the usability of EPW using the five-point Likert scale. We used the R Software to perform the Wilcoxon Mann-Whitney test as a statistical comparisons test between Group I and II. RESULTS: The results showed a statistically significant difference (p<0.05) between Group I and II in the evaluation of 16 heuristics. We identified an important set of heuristics that could help evaluate and improve the usability of EPW. CONCLUSION: The findings highlighted the importance of considering users' and developers' points of view in developing an EPW and its evaluation criteria. It could help the design of the device match the user's needs and expectations. The set of heuristics in this study can be adapted to evaluate other devices' usability using the heuristic evaluation approach.

Milk quality according to the daily range in farm production in the Mesoregion Central Mineira and Oeste of Minas Gerais regions, Brazil / Perfil da qualidade do leite de acordo com a faixa de produção diária da propriedade leiteira nas mesorregiões Central Mineira e do Oeste de Minas Gerais, Brasil

The objective of this work was to characterize milk production from the Central Mineira and Oeste Mesoregions regions in Minas Gerais State, Brazil, according to quality parameters such as somatic cell count, total bacteria count, and composition for specific production ranges. Average results for milk fat, protein, total and nonfat solids were compliant with Brazilian legal requirements (IN-62/2011) in all the production ranges selected. Average somatic cell counts (SCC) complied with the legal requirements of 600,000 cells/mL, except for the range with a daily production above 1,000 liters. However, average maximum values of 400,000 cells/mL are recommended for good milk quality. Total bacterial count was the most critical quality factor, with the highest values found in breeds with milk production above 500 liters per day.

O presente trabalho teve por objetivo caracterizar a produção de leite nas mesorregiões Central Mineira e do Oeste de Minas do estado de Minas Gerais, quanto à contagem de células somáticas, à contagem bacteriana total e à composição, em diferentes faixas de produção. Os teores de gordura, proteína, sólidos totais e extrato seco desengordurado apresentaram valores médios dentro do limite estabelecido pela Instrução Normativa n°62 (IN-62/2011), em todas as faixas específicas de produção estipuladas no presente trabalho. Os valores de contagem de células somáticas (CCS) também se mostraram dentro do limite legalmente estabelecido de 600.000 células/mL, exceto na faixa de produção acima de 1.000L/dia. Entretanto, valores abaixo de 400.000 células/mL são recomendados para um leite de boa qualidade. A contagem bacteriana total foi o fator de qualidade mais crítico. Os valores médios de contagem bacteriana ultrapassaram o limite atualmente preconizado, e rebanhos com volume diário acima de 500 litros por dia foram os que apresentaram maior número de resultados que não estão em conformidade com os padrões legais.

Pathogenicity for onion and genetic diversity of isolates of the pathogenic fungus Colletotrichum gloeosporioides (Phyllachoraceae) from the State of Pernambuco, Brazil.

Onion anthracnose, caused by Colletotrichum gloeosporioides, is one of the main diseases of onions in the State of Pernambuco. We examined the pathogenicity of 15 C. gloeosporioides strains and analyzed their genetic variability using RAPDs and internal transcribed spacers (ITS) of the rDNA region. Ten of the strains were obtained from substrates and hosts other than onion, including chayote (Sechium edule), guava (Psidium guajava), pomegranate (Punica granatum), water from the Capibaribe River, maracock (Passiflora sp), coconut (Cocus nucifera), surinam cherry (Eugenia uniflora), and marine soil; five isolates came from onions collected from four different regions of the State of Pernambuco and one region of the State of Amazonas. Pathogenicity tests were carried out using onion leaves and bulbs. All strains were capable of causing disease in leaves, causing a variable degree of lesions on the leaves; four strains caused the most severe damage. In the onion bulb tests, only three of the above strains caused lesions. Seven primers of arbitrary sequences were used in the RAPD analysis, generating polymorphic bands that allowed the separation of the strains into three distinct groups. The amplification products generated with the primers ITS1 and ITS4 also showed polymorphism when digested with three restriction enzymes, DraI, HaeIII and MspI. Only the latter two demonstrated genetic variations among the strains. These two types of molecular markers were able to differentiate the strain from the State of Amazonas from those of the State of Pernambuco. However, there was no relationship between groups of strains, based on molecular markers, and degree of pathogenicity for onion leaves and bulbs.

[Diffuse bone marrow metastasis in cerebellar high-grade astrocytoma. A case report]. / Metastasis difusa de la medula osea en un astrocitoma cerebeloso de alto grado. Un caso clinico.

INTRODUCTION: Cerebellar high-grade astrocytoma is uncommon. Although more prone to present cerebrospinal fluid dissemination, the cerebellar location is not particularly related to the occurrence of extra-cranial metastases, which are also unusual in supratentorial malignant gliomas. CASE REPORT: A 46 year-old man with cerebellar anaplastic astrocytoma who developed pancytopenia due to extensive bone marrow metastases. CONCLUSION: Extraneural metastases of brain gliomas are rare and the spread to the bone marrow confers an extremely poor prognosis for these patients. The expected improvement in glioma patients' survival due to the combination of more efficient therapies may lead to an increased incidence of this uncommon presentation, justifying a more rigorous follow-up of systemic manifestations.

MRI of medulloblastoma in adults.

Medulloblastoma has variable appearances on MRI in both children and adults. Adults are more likely to have heterogeneous cerebellar hemisphere tumours, and this is thought to be related to the greater prevalence of desmoplastic tumours in adulthood. Few studies have addressed the MRI features of adult medulloblastoma and the specific characteristics of desmoplastic and classic tumours have not been analysed. Our aim was to analyse the imaging characteristics of desmoplastic (DM) and classic (CM) medulloblastomas in adult. We retrospectively studied preoperative MRI of six men and three women, median age 33 years, range 23-53 years, with pathologically proved medulloblastomas. There were six (67%) with DM. The tumour was in the cerebellar hemisphere in eight patients (89%), including the three with CM, one of which was bilateral. All tumours were heterogeneous, giving predominantly low or isointense signal on T1- and isointense signal on T2-weighted images. Cystic or necrotic areas in all patients were particularly visible on T2-weighted images. Contrast enhancement was absent in one DM and varied from slight to intense in eight (three CM), homogeneous in one DM and patchy in seven. All tumours extended to the surface of the cerebellum and two had well-defined margins. MRI does not allow a clear distinction between DM and CM in adults.