Errors in chromosome segregation in mammalian oocytes increase in number with advancing maternal age, and are a major cause of pregnancy loss. Why chromosome segregation errors are more common in oocytes from older females remains poorly understood. In mitosis, accurate chromosome segregation is enabled by attachment of kinetochores to microtubules from appropriate spindle poles, and erroneous attachments increase the likelihood of mis-segregation. Whether attachment errors are responsible for age-related oocyte aneuploidy is unknown. Here we report that oocytes from naturally aged mice exhibit substantially increased chromosome misalignment, and fewer kinetochore pairs that make stable end-on attachments to the appropriate spindle poles compared with younger oocytes. The profile of mis-attachments exhibited is consistent with the types of chromosome segregation error observed in aged oocytes. Loss of chromosome cohesion, which is a feature of oocytes from older females, causes altered kinetochore geometry in meiosis-I. However, this has only a minor impact upon MT attachment, indicating that cohesion loss is not the primary cause of aneuploidy in meiosis-I. In meiosis-II, on the other hand, age-related cohesion loss plays a direct role in errors, since prematurely individualized sister chromatids misalign and misattach to spindle MTs. Thus, whereas cohesion loss leading to precocious sister chromatid separation is a direct cause of errors in meiosis-II, cohesion loss plays a more minor role in the etiology of aneuploidy in meiosis-I. Our data introduce altered MT-kinetochore interactions as a lesion that explains aneuploidy in meiosis-I in older females.

This article provides an analysis of the difficulties and barriers deaf and hard of hearing individuals face during the period of the COVID-19 pandemic. In a pandemic situation, apart from the economy, education is also largely affected. In the past few months, many disabled and non-disabled pupils and university students were taken by complete surprise by the immense changes in the education sector and mainly by the innovations introduced, especially in the lower education grades, which resulted in considerable implications, despite the positive response they received. In these trying times humanity is experiencing, the difficulties that deaf and hard of hearing individuals have to face were exacerbated, perpetuating their marginalisation. <p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0726/a.php" alt="Hit counter" /></p>

Core Ideas Environmental education in special education is feasible. Environmental education requires further training of educators. Environmental education is beneficial to children with disabilities. This investigation, conducted in Greece, inquired 80 special education teachers—via a structured questionnaire—their opinions on whether they feel ready to teach environmental education (EE) to pupils with disabilities, whether instruction of EE is possible in special or in regular education classes, and whether EE is beneficial to people with disabilities. The questionnaire had a unit with closed‐type questions on demographic data (sex, age, educational background, further training in special education, years of service, location of school) and the three units corresponding to the above thematic with a total of 15 questions, on EE and pupils with disabilities. The results showed that educators in general do not feel particularly prepared and ready to teach EE to pupils with disabilities, since they do not have the appropriate training nor sufficient knowledge on how to teach EE to children with disabilities, and in order for them to acquire this knowledge, it is necessary to receive further training on activities that provide ideas for planning such a course and on the various disabilities. The majority of them rejected the premise that EE is unfeasible in special education, but they were divided on the feasibility of teaching EE to all pupils in the disabilities spectrum and on the need of individualized instruction for successful participation in EE activities. Finally, there was a high positive agreement on the benefits of EE instruction on knowledge, socialization, and improvement of self‐esteem, but there was uncertainty on its possible positive influence on future vocational rehabilitation of students.

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