The first assimilation of Akatsuki single-layer winds and its validation with Venusian atmospheric waves excited by solar heating.

The planetary missions including the Venus Climate Orbiter 'Akatsuki' provide new information on various atmospheric phenomena. Nevertheless, it is difficult to elucidate their three-dimensional structures globally and continuously only from observations because satellite observations are considerably limited in time and space. We constructed the first 'objective analysis' of Venus' atmosphere by assimilating cloud-top horizontal winds on the dayside from the equator to mid-latitudes, which is frequently obtained from Akatsuki's Ultraviolet Imager (UVI). The three-dimensional structures of thermal tides, found recently to play a crucial role in maintaining the super rotation, are greatly improved by the data assimilation. This result is confirmed by comparison with Akatsuki's temperature observations. The momentum transport caused by the thermal tides and other disturbances are also modified by the wind assimilation and agrees well with those estimated from the UVI observations. The assimilated dataset is reliable and will be open to the public along with the Akatsuki observations for further investigation of Venus' atmospheric phenomena.

Latent changes in the pharyngeal stage of swallowing in non-aspirating older adults.

PURPOSE: The characteristic changes in the swallowing mechanism with aging are collectively termed presbyphagia. Although several studies have investigated presbyphagia in older adults, few have assessed oldest-old adults. We aimed to characterize the latent changes of swallowing function in oldest-old adults and to consider risk ages for presbyphagia. METHODS: We analyzed the records of 85 individuals (44 males and 41 females, aged 25-101 years) who underwent videofluoroscopic swallowing studies. The included participants had penetration and aspiration scores of ≤ 2 and no history of aspiration, pneumonia, or diseases that affect swallowing. They were divided into four age groups: 25-64 years (non-older), 65-74 years (young-old), 75-84 years (middle-old), and ≥ 85 years (oldest-old). We analyzed and compared the pharyngeal delay time (PDT), duration of tongue base and posterior pharyngeal wall contact, duration and dimension of upper esophageal sphincter opening (UES-O), and maximal hyoid bone displacement between the age groups. RESULTS: Among the older groups, the oldest-old showed significantly longer PDT than younger-old adults, and the UES-O tended to be wider in the former. However, no other remarkable differences were found between the oldest-old and other old groups. Statistical comparisons between the < 75 and ≥ 75-year age groups revealed significant age-related changes in the PDT and duration and dimension of UES-O. CONCLUSION: On videofluoroscopic evaluation, physiological changes with aging affected few parameters of swallowing in our cohort. These findings indicate that in non-aspirating oldest-old adults, any deterioration may be adjusted for by compensatory changes to maintain swallowing function.

Mapping the Ethical Issues of Brain Organoid Research and Application.

In 2008, researchers created human three-dimensional neural tissue - known as the pioneering work of "brain organoids." In recent years, some researchers have transplanted human brain organoids into animal brains for applicational purposes. With these experiments have come many ethical concerns. It is thus an urgent task to clarify what is ethically permissible and impermissible in brain organoid research. This paper seeks (1) to sort out the ethical issues related to brain organoid research and application and (2) to propose future directions for additional ethical consideration and policy debates in the field. Toward (1), this paper first outlines the current state of brain organoid research, and then briefly responds to previously raised related ethical concerns. Looking next at anticipated scientific developments in brain organoid research, we will discuss (i) ethical issues related to in vitro brain organoids, (ii) ethical issues raised when brain organoids form complexes or have relationships with other entities, and (iii) ethical issues of research ethics and governance. Finally, in pursuit of (2), we propose research policies that are mindful of the ethics of brain organoid research and application and also suggest the need for an international framework for research and application of brain organoids.

Generation of gravity waves from thermal tides in the Venus atmosphere.

Gravity waves play essential roles in the terrestrial atmosphere because they propagate far from source regions and transport momentum and energy globally. Gravity waves are also observed in the Venus atmosphere, but their characteristics have been poorly understood. Here we demonstrate activities of small-scale gravity waves using a high-resolution Venus general circulation model with less than 20 and 0.25 km in the horizontal and vertical grid intervals, respectively. We find spontaneous gravity wave radiation from nearly balanced flows. In the upper cloud layer (~70 km), the thermal tides in the super-rotation are primary sources of small-scale gravity waves in the low-latitudes. Baroclinic/barotropic waves are also essential sources in the mid- and high-latitudes. The small-scale gravity waves affect the three-dimensional structure of the super-rotation and contribute to material mixing through their breaking processes. They propagate vertically and transport momentum globally, which decelerates the super-rotation in the upper cloud layer (~70 km) and accelerates it above ~80 km.

How waves and turbulence maintain the super-rotation of Venus' atmosphere.

Venus has a thick atmosphere that rotates 60 times as fast as the surface, a phenomenon known as super-rotation. We use data obtained from the orbiting Akatsuki spacecraft to investigate how the super-rotation is maintained in the cloud layer, where the rotation speed is highest. A thermally induced latitudinal-vertical circulation acts to homogenize the distribution of the angular momentum around the rotational axis. Maintaining the super-rotation requires this to be counteracted by atmospheric waves and turbulence. Among those effects, thermal tides transport the angular momentum, which maintains the rotation peak, near the cloud top at low latitudes. Other planetary-scale waves and large-scale turbulence act in the opposite direction. We suggest that hydrodynamic instabilities adjust the angular-momentum distribution at mid-latitudes.

Planetary-scale streak structure reproduced in high-resolution simulations of the Venus atmosphere with a low-stability layer.

Cloud patterns are important clues for revealing the atmospheric circulation of Venus. Recently, a planetary-scale streak structure has been discovered in middle- and lower-cloud images of Venus' night-side taken by IR2, the 2-µm camera, on board the Akatsuki orbiter. However, its formation mechanism has not been investigated. Here we succeed, for the first time, in reproducing the patterns of the observed streak structure, as regions of strong downward flows that develop in high-resolution global simulations of the Venus atmosphere. The streaks are formed in both hemispheres with equatorial symmetry, which is caused by equatorial Rossby-like and Kelvin-like waves with zonal wavenumber one. The low-stability layer that has been suggested by past observations is essential for reproducing the streak structure. The streaks of downward flow result from the interaction of the meridionally tilted phase lines of the Rossby-like waves and the characteristics of baroclinic instability produced around the low-stability layer.

Case of adrenal lymphangioma with atypical lymphocytes in aspirate cytology.

Cytological diagnosis of adrenal cysts is becoming more important, with the increase in cases identified due to the widespread use of imaging modalities. Adrenal cysts have been classified into four main groups: endothelial, epithelial, parasitic, and pseudocyst, with endothelial cysts further classified as lymphangiomatous or angiomatous. We report on a case of adrenal lymphangioma with atypical lymphocytes found in the intraoperative aspirate, suggesting an inconclusive diagnosis, although immunohistochemical study led us to suppose their B-cell origin. This case provided important cytological findings that may assist in the prevention of cytological overdiagnosis.