Many bilaterally symmetric animals develop left–right (L–R) asymmetry in their internal organs. The mechanisms of L–R asymmetric development are well understood in vertebrates, whereas they are still ...elusive in invertebrates. Therefore, we decided to study the genetic pathway of L–R asymmetric development in
Drosophila. To identify the genes required for L–R asymmetric development in
Drosophila , we screened EMS (Ethylmethanesulfonate) induced mutations that affect stereotypical L–R asymmetry of the embryonic gut. From this screening, we isolated
arrow mutant that affected L–R asymmetry in the anterior midgut.
arrow is an ortholog of a mammalian gene encoding low-density lipoprotein receptor-related protein 5/6, which is a co-receptor in the Wnt signaling pathway. The anterior midgut consists of the visceral muscle and epithelial tube. Our analysis revealed that Wnt signal in the visceral muscle but not the epithelium of the midgut is reguired for the normal laterality development of this organ. However, the visceral muscle was formed normally in
arrow homozygous embryos, suggesting the Wnt signal probably functions in cell rearrangement, which is known to occur during L–R asymmetric development of the anterior midgut.
Drosophila genome encodes seven Wnt ligands. Therefore, we next determined ligands are required for the L–R asymmetric development of the anterior midgut. Homozygous embryos of
Wnt4 showed a similar laterality defects to those of
arrow mutants in the anterior midgut. These results suggest that Wnt signal activated by Wnt4 in the visceral muscle play an essential role in the L–R asymmetric development of the anterior midgut. Moreover, our analysis suggested that Wnt canonical pathway is required for the normal L–R asymmetric development of the anterior midgut.
•Cell-shape chirality is intrinsically formed in each individual cell.•The intrinsic cell-shape chirality is also influenced by surrounding cells.•Cell-shape chirality is affected by interactions ...among cells through mechanical force.
Many animals show left–right (LR) asymmetric morphology. The mechanisms of LR asymmetric development are evolutionarily divergent, and they remain elusive in invertebrates. Various organs in Drosophila melanogaster show stereotypic LR asymmetry, including the embryonic gut. The Drosophila embryonic hindgut twists 90° left-handedly, thereby generating directional LR asymmetry. We recently revealed that the hindgut epithelial cell is chiral in shape and other properties; this is termed planar cell chirality (PCC). We previously showed by computer modeling that PCC is sufficient to induce the hindgut rotation. In addition, both the PCC and the direction of hindgut twisting are reversed in Myosin31DF (Myo31DF) mutants. Myo31DF encodes Drosophila MyosinID, an actin-based motor protein, whose molecular functions in LR asymmetric development are largely unknown. Here, to understand how PCC directs the asymmetric cell-shape, we analyzed PCC in genetic mosaics composed of cells homozygous for mutant Myo31DF, some of which also overexpressed wild-type Myo31DF. Wild-type cell-shape chirality only formed in the Myo31DF-overexpressing cells, suggesting that cell-shape chirality was established in each cell and reflects intrinsic PCC. A computer model recapitulating the development of this genetic mosaic suggested that mechanical interactions between cells are required for the cell-shape behavior seen in vivo. Our mosaic analysis also suggested that during hindgut rotation in vivo, wild-type Myo31DF suppresses the elongation of cell boundaries, supporting the idea that cell-shape chirality is an intrinsic property determined in each cell. However, the amount and distribution of F-actin and Myosin II, which are known to help generate the contraction force on cell boundaries, did not show differences between Myo31DF mutant cells and wild-type cells, suggesting that the static amount and distribution of these proteins are not involved in the suppression of cell-boundary elongation. Taken together, our results suggest that cell-shape chirality is intrinsically formed in each cell, and that mechanical force from intercellular interactions contributes to its formation and/or maintenance.
Several studies have investigated the relationship between working memory and attention. However, most of the relevant studies so far investigated top-down attention; only a few have examined ...possible interactions between bottom-up attention and visual working memory. In the present study, we focused on the visual saliency of different parts of pictures as an index of the degree to which one’s bottom-up attention can be drawn towards each of them. We administered the Picture Span Test (PST) to investigate whether salient parts of pictures can influence the performance of visual working memory. The task required participants to judge the semantic congruency of objects in pictures and remember specific parts of pictures. In Experiment 1, we calculated a saliency map for the PST stimuli and found that salient but task-irrelevant parts of pictures could evoke intrusion errors. In Experiment 2, we demonstrated that longer gazing time at target areas results in a higher probability of making correct recognition. In addition, frequent gaze fixation and high normalized scan-path saliency values in task-irrelevant areas were associated with intrusion errors. These results suggest that visual information processed by bottom-up attention may affect working memory.
To quantify the flood risk awareness of real estate market participants and residents, previous studies analyzed the effect of flood risks on residential property values. However, most studies ...focused on the impact of recent flood events and the publication of new flood risk information; the behavior in flood-prone regions in which repeated damages occurred and lessons learned consequently has not been the focus of analysis. Moreover, there is a growing national concern in Japan about an increase in future flood risks due to climate change, although their effect on property values has not been discussed. In this study, we analyzed residential property values in Nagoya City (Aichi Prefecture, Japan), a megacity that has experienced significant flood damage in major historical and recent floods. The main objective of this study is to determine the effects of past and recent flood experiences and the increasing concerns about flood risks on recent residential property values. The results revealed that historical flood damage had the largest impact on residential property values in Nagoya City, and devaluation increased due to growing concerns about natural disasters in Japan. The disclosure of flood risk information also had an impact on property values, increasing devaluation after disclosure. On the contrary, the occurrence of recent floods did not have an impact on property values, suggesting that flood risk awareness had already been strong in the target area. These findings are different from those of many previous studies. The observed trends in residential property values in the target area are likely a characteristic response in flood-prone regions, where flood risk awareness is enhanced due to repeated flood damage.
The purpose of this study was to identify the ex-ante determinants of disaster preparedness in daily life, termed everyday awareness of disaster preparedness, which influence evacuation behavior ...during heavy rainfall events. A panel survey was conducted among residents of flood- and landslide-prone areas in Ehime Prefecture before and after heavy rainfall. A pre-survey explored a wide range of variables related to participants’ everyday awareness of disaster preparedness prior to heavy rains, followed by a post-survey that examined their actual evacuation behavior when evacuation warnings were issued during subsequent heavy rains. By analyzing the survey data, we identified prior variables related to disaster preparedness that were associated with evacuation choice. The participants had a high level of disaster preparedness, including evacuation intentions, but many of them did not actually evacuate even when evacuation warnings were issued due to heavy rains. Furthermore, only prior contemplation of evacuation criteria (associated with the commitment to evacuate) was directly related to evacuation behavior. Finally, mediation analysis indicated that prior contemplation mediated the relationship between evacuation intentions and actual evacuation. The implications of these findings for education and communications to reduce disaster risk are discussed.
Single-center studies indicated a high diagnostic accuracy of dynamic computed tomography perfusion (CTP) imaging in the diagnosis of coronary artery disease (CAD).
This prospective multicenter study ...determined the diagnostic performance of combined coronary computed tomography angiography (CTA) and CTP for detecting hemodynamically significant CAD defined by invasive coronary angiography (ICA) with fractional flow reserve (FFR).
Seven centers enrolled 174 patients with suspected or known CAD who were clinically referred for ICA. CTA and dynamic CTP were performed using dual-source CT before ICA. FFR was done as part of ICA in the case of 26% to 90% coronary diameter stenosis. Hemodynamically significant stenosis was defined as FFR of <0.8 or >90% stenosis on ICA.
The study protocol was completed in 157 participants, and hemodynamically significant stenosis was detected in 76 of 157 patients (48%) and 112 of 442 vessels (25%). According to receiver-operating characteristic curve analysis, adding dynamic CTP to CTA significantly increased the area under the curve from 0.65 (95% CI: 0.57-0.72) to 0.74 (95% CI: 0.66-0.81; P = 0.011) on the patient level, with decreased sensitivity (93% vs 72%; P < 0.001), improved specificity (36% vs 75%; P < 0.001), and improved overall accuracy (64% vs 74%; P < 0.001).
In this prospective multicenter study on dynamic CTP, the combination of anatomic assessment with coronary CTA and functional evaluation with dynamic CTP allowed more accurate identification of hemodynamically significant CAD compared with CTA alone. However, the clinical significance of this approach needs to be further investigated, including its usefulness in improving prognosis. (Assessment of Myocardial Perfusion Linked to Infarction and Fibrosis Explored With Dual-Source CT AMPLIFiED; UMIN000016353)
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