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The karyotype of an organism is the set of gross features that characterize the way the genome is packaged into separate chromosomes. It has been known for decades that different taxonomic groups often have distinct karyotypic features, but whether selective forces act to maintain these differences over evolutionary timescales is an open question. In this paper we analyze a database of karyotype features and sperm head morphology in 103 mammal species with spatulate sperm heads and 90 sauropsid species (birds and non-avian reptiles) with vermiform heads. We find that mammal species with a larger head area have more chromosomes, while sauropsid species with longer heads have a wider range of chromosome lengths. These results remain significant after controlling for genome size, so sperm head morphology is the relevant variable. This suggest that post-copulatory sexual selection, by acting on sperm head shape, can influence genome architecture.

The term code-switching (CS) that occurs in everyday situations, or naturalistic code-switching, has been a controversial strategy regarding whether it benefits or impedes language learning. The aim of this study was to investigate CS in conversations between teachers and students of ESP classes in order to explore the types and functions of CS usually used in the teaching and learning process, and to investigate the teachers' and students' opinions about CS in classroom practice, particularly in English for nursing and tourism classes. The study found that code-switching was one of the major strategies in these ESP classes. CS in the teaching process could be categorized according to the following: inter-sentential switching, intra-sentential switching, extra-sentential switching, and code selection. The CS functions were both pedagogical (asking questions, giving explanations, translating, and emphasizing ideas) and social functions (directing, reminding, injecting humor, and encouraging students). The majority of the teachers demonstrated positive opinions about CS and agreed that CS from English to Thai could benefit their classes, as it is one of the most effective strategies for helping their students obtain clear ideas on the subject matter. This strategy not only made the students understand more of the lesson but also increased their confidence and comfort in the teaching process. The CS characteristics and opinions found in this study may provide a guideline for language teachers and policymakers, especially in EFL countries in the AEC and in this global era.

Abstract Background The demand for palliative care in hospitals in Thailand has rapidly increased in recent years. Subsequently, the way in which palliative care systems should be arranged to facilitate the care process and patient preparation for their end stage of life is still an ongoing debate among policy makers and researchers. Although palliative care is provided in most facilities, there is no clear protocol for palliative care due to a lack of empirical evidence. Thus, this study attempts to analyse the situation and quality of palliative care provision in Thai public hospitals. Methods A cross-sectional study was conducted in 2018. A questionnaire with measures concerning hospital characteristics, the structure of palliative care provision, and processes related to achieving a good death was developed. The questionnaire was sent to all 862 public hospitals across 76 provinces, and the response rate was 62.88%. A structural equation model was specified to operationalize Donabedian’s framework. To our knowledge, this is the first nationwide study to investigate facility-level palliative care provision in Thailand. Results The study results confirmed the relationships between the structure and process of palliative care provision in hospitals. The sufficiency and competency of doctors and nurses and the variety of relaxation equipment were either directly or indirectly associated with the process components relevant to the response to the patient’s needs, effective communication, and respect for the patient’s dignity. In addition, the performance of palliative care research in hospitals was associated with the response to the patient’s needs and effective communication, while the allocation of physical areas was associated with effective communication. Conclusion This model can be used to evaluate the overall situation of palliative care provision at the national level. It could also contribute to the development of standard measurements for evidence-based palliative care quality improvement in hospitals.

During mitosis in higher eukaryotes, each chromosome condenses into a pair of rod-shaped chromatids. This process is co-regulated by the activity of several gene families, and the underlying biophysics remains poorly understood. To better understand the factors regulating chromosome condensation, we compiled a database of mitotic chromosome size and DNA content from the tables and figures of >200 published papers. A comparison across vertebrate species shows that chromosome width, length and volume scale with DNA content to the powers ∼1/4, ∼1/2, and ∼1, respectively. Angiosperms (flowering plants) show a similar length scaling, so this result is not specific to vertebrates. Chromosome shape and size thus satisfy two conditions: (1) DNA content per unit volume is approximately constant and (2) the cross-sectional area increases proportionately with chromosome length. Since viscous drag forces during chromosome movement are expected to scale with length, we hypothesize that the cross-section increase is necessary to limit the occurrence of large chromosome elongations that could slow or stall mitosis. Lastly, we note that individual vertebrate karyotypes typically exhibit a wider range of chromosome lengths as compared with angiosperms.