207 research outputs found

    The Golden City on the Edge: Economic Geography and Jihad over Centuries

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    This paper uncovers the evolution of cities and Islamist insurgencies, so called jihad, in the process of the reversal of fortune over the centuries. In West Africa, water access in ancient periods predicts the locations of the core cities of inland trade routes -- the trans-Saharan caravan routes -- founded up to the 1800s, when historical Islamic states played significant economic roles before European colonization. In contrast, ancient water access does not have a persistent influence on contemporary city formation and economic activities. After European colonization and the invention of modern trading technologies, along with the constant shrinking of water sources, landlocked pre-colonial core cities contracted or became extinct. Employing an instrumental variable strategy, we show that these deserted locations have today been replaced by battlefields for jihadist organizations. We argue that the power relations between Islamic states and the European military during the 19th century colonial era shaped the persistence of jihadist ideology as a legacy of colonization. Investigations into religious ideology related to jihadism, using individual-level surveys from Muslims, support this mechanism. Moreover, the concentration of jihadist violence in "past-core-and-present-periphery" areas in West Africa is consistent with a global-scale phenomenon. Finally, spillovers of violent events beyond these stylized locations are partly explained by organizational heterogeneity among competing factions (Al Qaeda and the Islamic State) over time

    Hot Cell-Direct PCR Aimed at Specific Cell Detection

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    Since the polymerase chain reaction (PCR) was proposed, it has become an essential method in the field of biological gene analysis, providing a method to amplify DNA sequences of interest. To detect and/or analyze genes in cells, the gene or expressed gene must first be extracted before PCR. This procedure takes time and may result in the loss of samples. In order to avoid such drawbacks, two methods, hot cell-direct PCR and reverse transcription-PCR (RT-PCR), were invented, to detect genes in cells. Using hot cell-direct PCR, specific genes in microbial cells such as invA in Salmonella enterica have been easily detected and applied to discriminate Archaea from bacteria. As hot cell-direct PCR and RT-PCR are fairly simple processes, they can be applied to detect genes in single cells. We developed an original compact disc (CD)-shaped microfluidic device with microchambers for single-cell isolation and a detection system for expressed genes in isolated single cells in a microchamber on the device. We succeeded in the detection of PCR and RT-PCR products in individual cells and successfully detected S. enterica cells by hot cell-direct PCR. Expressed genes in Jurkat cells—human leukemia T cells—were analyzed by this method

    Subtemporal approach to basilar tip aneurysm with division of posterior communicating artery: Technical note

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    The subtemporal approach with division of the posterior communicating artery (PcomA) is described for treating aneurysms of the basilar tip. When the ipsilateral posterior cerebral artery (PCA) interferes with visibility and manipulation around the aneurysm neck and the artery is tethered by the PcomA and not mobilized, the PcomA can be divided near the junction with the PCA. The procedure permits PCA mobilization and exposes the neck of the aneurysm. We applied this procedure to a patient with a ruptured aneurysm of the basilar tip. The postoperative course was uneventful except for transient left oculomotor nerve palsy. Postoperative cerebral angiography and magnetic resonance imaging confirmed the respective disappearance of the aneurysm and no new ischemic lesions. The subtemporal approach allows safer and easier division of the PcomA near the junction to the PCA compared with the pterional approach, and the present procedure is more suitable for the subtemporal approach

    Fabrication of submicron La2−x_{2-x}Srx_{x}CuO4_{4} intrinsic Josephson junction stacks

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    Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have potential to be implemented as intrinsic phase qubits working at relatively high temperatures. We report success in fabricating submicron La2−x_{2-x}Srx_{x}CuO4_{4} (LSCO) IJJ stacks carved out of single crystals. We also show a new fabrication method in which argon ion etching is performed after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in which resistive multi-branches appeared. It may be possible to control the number of stacked IJJs with an accuracy of a single IJJ by developing this method.Comment: 5 pages, 6 figure

    HFIGMI–VMAT for brain metastases

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    Volumetric-modulated arc therapy (VMAT) can be used to design hypofractionated radiotherapy treatment plans for multiple brain metastases. The purpose of this study was to evaluate treatment outcomes of hypofractionated image-guided multifocal irradiation using VMAT (HFIGMI–VMAT) for brain metastases. From July 2012 to December 2016, 67 consecutive patients with 601 brain metastases were treated with HFIGMI–VMAT at our institution. The prescribed dose was 50 Gy to a 95% volume of the planning target volume in 10 fractions. Fifty-five of the 67 patients had non-small-cell lung cancer, and the remaining 12 had other types of cancer. The median number of brain metastases was five, and the median maximum diameter was 1.2 cm. The median duration of follow-up was 12.0 months (range, 1.9–44.8 months), and the median survival time 18.7 months. Four patients with six lesions had local recurrences. The local control rate in the 64 assessed patients was 98.4% and 95.3% at 6 and 12 months, respectively (three died before assessment). The local control rate for the 572 assessed lesions was 99.8% and 99.3% at 6 and 12 months, respectively. Thirty-nine patients developed distant brain metastases, the distant brain control rate being 59.7% and 40.5% at 6 and 12 months, respectively. Acute toxicities were generally mild (Grade 1–2). Three patients (4.5%) developed radiation necrosis requiring corticosteroid therapy. The HFIGMI–VMAT technique with flat dose delivery was well tolerated and achieved excellent local control. This technique is a promising treatment option for patients with multiple and large brain metastases

    Fosfluconazole for Antifungal Prophylaxis in Very Low Birth Weight Infants

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    We conducted a retrospective case series study to evaluate the safety of fosfluconazole prophylaxis for preventing invasive fungal infection in VLBW infants with a central vascular access. Fosfluconazole was administered intravenously at a dose of 6 mg/kg everyday during which time a central venous catheter was placed. A total of 23 infants met the criteria for enrollment in our study. No cases of fungal infection were detected during the central venous catheter placement in the group. None of the infants had an elevated β-D-glucan, and all of them were still alive at discharge. Regarding the liver and renal function, no statistically significant differences were observed before and at the end of fosfluconazole prophylaxis. The results of this study demonstrate that fosfluconazole prophylaxis in preventing invasive fungal infection was well tolerated by VLBW infants. This is a first report to describe antifungal prophylaxis using fosfluconazole for VLBW infants

    Effectiveness of Newly Developed Water-Equivalent Mouthpiece during External Beam Radiotherapy for Oral Cancer

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    The objective of this study was to research the effectiveness of newly developed water-equivalent mouthpiece during external beam radiotherapy for oral cancer. In external beam radiotherapy for cancer of the tongue, floor of the mouth, and lower gingiva, it is possible to prescribe a low dose to the upper gingiva and hard palate at an open mouth position using a mouthpiece. However, the inhomogeneity correction resulting from the air cavity and the mobility of the tongue produced by an open mouth position should be considered. Therefore, a new mouthpiece was designed to be fixed by the dental arch, and the air cavity of the mouth can be filled with water-equivalent material. In 30 patients with previously treated oral cancer, the simulated homogeneity index of the calculated water-equivalent mouthpiece by a treatment-planning system was significantly better than that of a conventional mouthpiece (p = 0.004). This new mouthpiece facilitates excellent dose distribution while attaining immobilization of the tongue in patients with oral cancer

    Effect of dental metal artifact conversion volume on dose distribution in head‐and‐neck volumetric‐modulated arc therapy

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    Purpose: During treatment planning for head‐and‐neck volumetric‐modulated arc therapy (VMAT), manual contouring of the metal artifact area of artificial teeth is done, and the area is replaced with water computed tomography (CT) values for dose calculation. This contouring of the metal artifact areas, which is performed manually, is subject to human variability. The purpose of this study is to evaluate and analyze the effect of inter‐observer variation on dose distribution. Methods: The subjects were 25 cases of cancer of the oropharynx for which VMAT was performed. Six radiation oncologists (ROs) performed metal artifact contouring for all of the cases. Gross tumor volume, clinical target volume, planning target volume (PTV), and oral cavity were evaluated. The contouring of the six ROs was divided into two groups, small and large groups. A reference RO was determined for each group and the dose distribution was compared with those of the other radiation oncologists by gamma analysis (GA). As an additional experiment, we changed the contouring of each dental metal artifact area, creating enlarged contours (L), reduced contours (S), and undrawn contours (N) based on the contouring by the six ROs and compared these structure sets. Results: The evaluation of inter‐observer variation showed no significant difference between the large and small groups, and the GA pass rate was 100%. Similar results were obtained comparing structure sets L and S, but in the comparison of structure sets L and N, there were cases with pass rates below 70%. Conclusions: The results show that the artificial variability of manual artificial tooth metal artifact contouring has little effect on the dose distribution of VMAT. However, it should be noted that the dose distribution may change depending on the contouring method in cases where the overlap between PTV and metal artifact areas is large
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