153 research outputs found

    Comparison of gravity wave propagation directions observed by mesospheric airglow imaging at three different latitudes using the M-transform

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    We developed user-friendly software based on Matsuda et al.'s (2014) 3D-FFT method (Matsuda-transform, M-transform) for airglow imaging data analysis as a function of Interactive Data Language (IDL). Users can customize the range of wave parameters to process when executing the program. The input for this function is a 3-D array of a time series of a 2-D airglow image in geographical coordinates. We applied this new function to mesospheric airglow imaging data with slightly different observation parameters obtained for the period of April–May at three different latitudes: Syowa Station, the Antarctic (69∘&thinsp;S, 40∘&thinsp;E); Shigaraki, Japan (35∘&thinsp;N, 136∘&thinsp;E); and Tomohon, Indonesia (1∘&thinsp;N, 122∘&thinsp;E). The day-to-day variation of the phase velocity spectrum at the Syowa Station is smaller and the propagation direction is mainly westward. In Shigaraki, the day-to-day variation of the horizontal propagation direction is larger than that at the Syowa Station; the variation in Tomohon is even larger. In Tomohon, the variation of the nightly power spectrum magnitude is remarkable, which indicates the intermittency of atmospheric gravity waves (AGWs). The average nightly spectrum obtained from April–May shows that the dominant propagation is westward with a phase speed &lt;50&thinsp;m&thinsp;s−1 at the Syowa Station and east-southeastward with a phase speed of up to ∼80&thinsp;m&thinsp;s−1 in Shigaraki. The day-to-day variation in Tomohon is too strong to discuss average characteristics; however, a phase speed of up to ∼100&thinsp;m&thinsp;s−1 and faster is observed. The corresponding background wind profiles derived from MERRA-2 indicate that wind filtering plays a significant role in filtering out waves that propagate eastward at the Syowa Station. On the other hand, the background wind is not strong enough to filter out relatively high-speed AGWs in Shigaraki and Tomohon and the dominant propagation direction is likely related to the distribution and characteristics of the source region, at least in April and May.</p

    Acute small bowel obstruction as a result of a Meckel's diverticulum encircling the terminal ileum: A case report

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    BACKGROUND: In the developed world, small bowel obstruction accounts for 20% of all acute surgical admissions. The aetiology for majority of these cases includes postoperative adhesions and herniae. However, a relatively uncommon cause is a Meckel's diverticulum. Although this diagnosis is primarily reported in the adolescent population, it should also be considered in adults. CASE PRESENTATION: In the present report, we present a rare case where a fit and healthy 74-year-old gentleman, with no previous history of abdominal surgery, presented with the cardinal symptoms and signs of small bowel obstruction as the result of a Meckel's diverticulum encircling his terminal ileum. Initial investigations included a supine abdominal x-ray showing dilated loops of small bowel and computerised tomographic imaging of the abdomen, which revealed a stricture in the terminal ileum of unknown aetiology. At laparotomy, multiple loops of distended small bowel were seen from the duodeno-jeujenal junction to the terminal ileum, which was encircled by a Meckel's diverticulum. The Meckel's diverticulum was then divided to release the obstruction, mobilised and subsequently removed. Finally, the small bowel contents were decompressed into the stomach and the nasogastric tube aspirated, before returning the loops of bowel into the abdomen in sequence. The patient made a good postoperative recovery and was discharged home 5 days later. CONCLUSION: This report highlights the importance of considering a Meckel's diverticulum as a cause of small bowel obstruction in individuals from all age groups and especially in a person with no previous abdominal pathology or surgery

    Characteristics of mesospheric gravity waves over Antarctica observed by Antarctic Gravity Wave Instrument Network imagers using 3-D spectral analyses

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    We have obtained horizontal phase velocity distributions of the gravity waves around 90 km from four Antarctic airglow imagers, which belong to an international airglow imager/instrument network known as ANGWIN (Antarctic Gravity Wave Instrument Network). Results from the airglow imagers at Syowa (69°S, 40°E), Halley (76°S, 27°W), Davis (69°S, 78°E) and McMurdo (78°S, 167°E) were compared, using a new statistical analysis method based on 3-D Fourier transform [Matsuda et al., 2014] for the observation period between 7 April and 21 May 2013. Significant day-to-day and site-to-site differences were found. The averaged phase velocity spectrum during the observation period showed preferential westward direction at Syowa, McMurdo and Halley, but no preferential direction at Davis. Gravity wave energy estimated by I’/I was ~5 times larger at Davis and Syowa than at McMurdo and Halley. We also compared the phase velocity spectrum at Syowa and Davis with the background wind field and found that the directionality only over Syowa could be explained by critical level filtering of the waves. This suggests that the eastward propagating gravity waves over Davis could have been generated above the polar night jet. Comparison of nighttime variations of the phase velocity spectra with background wind measurements suggested that the effect of critical level filtering could not explain the temporal variation of gravity wave directionality well, and other reasons such as variation of wave sources should be taken into account. Directionality was determined to be dependent on the gravity wave periods

    Mucosa-associated lymphoid tissue lymphoma and concurrent adenocarcinoma of the prostate

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    Primary mucosa-associated lymphoid tissue (MALT) lymphoma of the prostate is a rare disease that characteristically follows an indolent course. It is believed that infection or chronic inflammation may be triggers for malignant transformation in the prostate, but it is of unknown etiology. Reports of MALT lymphomas of the prostate with other concurrent primary prostate cancers are even more limited. We present the unique case of a 67-year-old male with concurrent adenocarcinoma of the prostate and primary MALT lymphoma of the prostate. The patient was treated with standard therapy for prostate adenocarcinoma, which would also treat a primary MALT lymphoma. He has been disease-free for over one year for both his primary malignancies. This case confirms that MALT lymphoma can arise concurrently with adenocarcinoma of the prostate

    Insufficient maintenance DNA methylation is associated with abnormal embryonic development

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    <p>Abstract</p> <p>Background</p> <p>Early pregnancy loss (EPL) is a frustrating clinical problem, whose mechanisms are not completely understood. DNA methylation, which includes maintenance methylation and <it>de novo </it>methylation directed by DNA methyltransferases (DNMTs), is important for embryo development. Abnormal function of these DNMTs may have serious consequences for embryonic development.</p> <p>Methods</p> <p>To evaluate the possible involvement of DNA methylation in human EPL, the expression of DNMT proteins and global methylation of DNA were assessed in villous or decidua from EPL patients. The association of maintenance methylation with embryo implantation and development was also examined.</p> <p>Results</p> <p>We found that DNMT1 and DNMT3A were both expressed in normal human villous and decidua. DNMT1 expression and DNA global methylation levels were significantly down-regulated in villous of EPL. DNMT3A expression was not significantly changed in the EPL group compared to controls in either villous or decidua. We also found that disturbance of maintenance methylation with a DNMT1 inhibitor may result in a decreased global DNA methylation level and impaired embryonic development in the mouse model, and inhibit <it>in vitro </it>embryo attachment to endometrial cells.</p> <p>Conclusions</p> <p>Our results demonstrate that defects in DNA maintenance methylation in the embryo, not in the mother, are associated with abnormal embryonic implantation and development. The findings of the current study provide new insights into the etiology of EPL.</p
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