80 research outputs found

    TIME SERIES ANALYSIS OF SURFACE DEFORMATION OF BENGALURU CITY USING SENTINEL-1 IMAGES

    Get PDF
    Persistent Scatterer Interferometry (PSI) is an advanced technique to map ground surface displacements of an area over a period. The technique can measure deformation with a millimeter-level accuracy. It overcomes the limitations of Differential Synthetic Aperture Radar Interferometry (DInSAR) such as geometric, temporal decorrelation and atmospheric variations between master and slave images. In our study, Sentinel-1A Interferometric Wide Swath (IW) mode descending pass images from May 2016 to December 2017 (23 images) are used to identify the stable targets called persistent scatterers (PS) over Bengaluru city. Twenty-two differential interferograms are generated after topographic phase removal using the SRTM 30 m DEM. The main objective of this study is to analyze urban subsidence in Bengaluru city in India using the multi-temporal interferometric technique such as PSI. The pixels with Amplitude Stability Index ≥ 0.8 are selected as initial PS candidates (PSC). Later, the PSCs having temporal coherence > 0.5 are selected for the time series analysis. The number of PSCs that are identified after final selection are reduced from 59590 to 54474 for VV polarization data and 15611 to 15596 for VH polarization data. It is interesting to note that a very less number of PSC are identified in cross-polarized images (VH). A high number of PSC have identified in co-polarized (VV) images as the vertically oriented urban targets produce a double bounce, which results in a strong return towards the sensor. The velocity maps obtained using VV and VH polarizations show displacement in the range of ± 20 mm year−1. The subsidence and the upliftment observed in the city shows a linear trend with time. It is observed that the eastern part of Bengaluru city shows more subsidence than the western part

    MAPPING SURFACE FLOW VELOCITIES OF SIACHEN AND GANGOTRI GLACIERS USING TERRASAR-X AND SENTINEL-1A DATA BY INTENSITY TRACKING

    Get PDF
    Glaciers are melting at an alarming rate due to global warming. Two major glaciers of India viz. Gangotri and the Siachen are chosen for the velocity mapping. The line-of-sight (LOS) velocity fields are derived using X-band TerraSAR-X and C-band Sentinel-1A datasets. An intensity-based offset tracking method is used to generate LOS velocities of the glaciers. The single look complex (SLC) images of the TerraSAR-X are converted into intensity before applying the offset tracking method, whereas the ground range detected (GRD) products from Sentinel-1A are directly used to estimate the glacier velocities. The Siachen glacier velocity is mapped using three X-band images from 2011 to 2017 and a C-band image between 2017 and 2018. The X-band images in the case of Siachen are available with the long-time interval between the master and slave images. The velocity of the glacier is observed to be around 30–40 cm day−1 from X-band and around 45–50 cm day−1 from C-band. Three X-band images in the year 2012 and a C-band image in the year 2018 are used for the Gangotri glacier velocity estimation. These images are very closely separated in time, and the velocity of the glacier is found to be 15–20 cm day−1. A dataset with a temporal gap of approximately three years is also used for the Gangotri glacier velocity estimation and observed a large difference in velocity (∼10 cm day−1) from that of shorter interval data. Therefore, for a slow-moving glacier like Gangotri, a dataset with a high temporal gap may not give a reliable result. It is also observed that X-band TerraSAR-X results are more accurate than the C-band Sentinel-1A results. The penetration depth of X-band is less compared to C-band, which might result in accurate estimation of glacier surface flow. According to the results, the velocity of the Siachen glacier is increasing at a very high rate

    Impact of nephrolithiasis on kidney function.

    Get PDF
    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Kidney stone disease has been associated with reduced kidney function and chronic kidney disease (CKD). The objective of the study was to examine kidney function, body mass index (BMI) and the prevalence of cardiovascular disease, hypertension and diabetes in recurrent kidney stone formers.A cross-sectional, case-control study comparing measures of kidney function, BMI and comorbid conditions was conducted in 195 kidney stone patients aged 18 to 70 years with recurrent clinical stone events and 390 age- and gender-matched controls. Wilcoxon-Mann-Whitney, chi-square tests and analysis of covariance were used to compare serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) between the groups.The median age of stone formers was 51 (range, 19-70) years and 108 (55 %) were males. Seventy patients (36 %) had experienced 2-4 clinical stone events, 41 (21 %) 5-10 episodes and 84 (43 %) more than 10. The median SCr was 75 (41-140) μmol/L in the stone formers and 64 (34-168) μmol/L in the control group (p < 0.001). The mean eGFR was 87 ± 20 and 104 ± 22 mL/min/1.73 m(2) in the stone formers and controls, respectively (p < 0.001). After adjustment for body size and comorbid conditions, the difference in SCr and eGFR between cases and controls remained highly significant (p < 0.001). The prevalence of CKD was 9.3 % among stone formers compared with 1.3 % in the control group (P < 0.001). Hypertension and diabetes were significantly more prevalent among the cases that also had higher BMI than controls.Recurrent kidney stone formers have a significantly lower level of kidney function and a markedly higher prevalence of CKD than age- and gender-matched control subjects. The observed deleterious effect of kidney stones on kidney function appears to be independent of comorbid conditions.Landspitali University Hospital Research Fun

    Rancang Bangun Alat Praktikum Hukum Ohm untuk Memfasilitasi Kemampuan Berfikir Tingkat Tinggi (Higher Order Thinking Skills)

    Full text link
    Tujuan dari penelitian ini adalah pembuatan alat praktikum hukum Ohm yang tidak hanya memfasilitasi siswa untuk melakukan praktikum hukum Ohm, melainkan juga memfasilitasi siswa untuk memiliki keterampilan berfikir tingkat tinggi / Higher Order Thinking Skilss (HOTS) melalui kegiatan praktikum. Proses pembuatan alat praktikum hukum Ohm ini melalaui tiga tahapan yaitu : merancang, membuat, dan menguji. Pada proses merancang, alat praktikum didesain sedemikian rupa agar mampu melatihkan keterampilan berfikir tingkat tinggi, utamanya pada kemampuan menganalisis dan mengkreasi. Pada proses membuat, pembuatan alat praktikum menggunakan bantuan sinar laser, agar alat praktikum tidak mudah pecah dan penampilannya bagus. Pada proses terakhir, yaitu menguji, proses penujian bertujuan untuk membuktikan bahwa alat praktikum dapat digunakan siswa untuk menemukan konsep hukum Ohm. Hasil proses pengujian menunjukan bahwa alat praktikum dapat digunakan untuk menemukan konsep hukum Ohm, selain itu alat praktikum jug dapat digunakan untuk melatihkan kemampuan berfkir tingkat tinggi pada siswa

    Anthropology, Brokerage and Collaboration in the development of a Tongan Public Psychiatry: Local Lessons for Global Mental Health

    Get PDF
    The Global Mental Health (GMH) movement has revitalised questions of the translatability of psychiatric concepts and the challenges of community engagement in countries where knowledge of the biomedical basis for psychiatric diagnosis is limited or challenged by local cultural codes. In Tonga, the local psychiatrist Dr Puloka has successfully established a publicly accessible psychiatry that has raised admission rates for serious mental illness and addressed some of the stigma attached to diagnosis. On the basis of historical analysis and ethnographic fieldwork with healers, doctors and patients since 1998, this article offers an ethnographic contextualization of the development and reception of three key interventions during the 1990s inspired by traditional healing and reliant on the translation of psychiatric terms and diagnosis. Dr Puloka’s use of medical anthropological and transcultural psychiatry research informed a community engaged brokerage between the implications of psychiatric nosologies and local needs. As such it reveals deficiencies in current polarised positions on the GMH project and offers suggestions to address current challenges of the Global Mental Health movement

    Inhibition of pluripotency networks by the Rb tumor suppressor restricts reprogramming and tumorigenesis

    Get PDF
    Mutations in the retinoblastoma tumor suppressor gene Rb are involved in many forms of human cancer. In this study, we investigated the early consequences of inactivating Rb in the context of cellular reprogramming. We found that Rb inactivation promotes the reprogramming of differentiated cells to a pluripotent state. Unexpectedly, this effect is cell cycle independent, and instead reflects direct binding of Rb to pluripotency genes, including Sox2 and Oct4, which leads to a repressed chromatin state. More broadly, this regulation of pluripotency networks and Sox2 in particular is critical for the initiation of tumors upon loss of Rb in mice. These studies therefore identify Rb as a global transcriptional repressor of pluripotency networks, providing a molecular basis for previous reports about its involvement in cell fate pliability, and implicate misregulation of pluripotency factors such as Sox2 in tumorigenesis related to loss of Rb function

    Inhibition of pluripotency networks by the Rb tumor suppressor restricts reprogramming and tumorigenesis

    Get PDF
    Mutations in the retinoblastoma tumor suppressor gene Rb are involved in many forms of human cancer. In this study, we investigated the early consequences of inactivating Rb in the context of cellular reprogramming. We found that Rb inactivation promotes the reprogramming of differentiated cells to a pluripotent state. Unexpectedly, this effect is cell cycle independent, and instead reflects direct binding of Rb to pluripotency genes, including Sox2 and Oct4, which leads to a repressed chromatin state. More broadly, this regulation of pluripotency networks and Sox2 in particular is critical for the initiation of tumors upon loss of Rb in mice. These studies therefore identify Rb as a global transcriptional repressor of pluripotency networks, providing a molecular basis for previous reports about its involvement in cell fate pliability, and implicate misregulation of pluripotency factors such as Sox2 in tumorigenesis related to loss of Rb function

    Nail lacquer films’ surface energies and in vitro water-resistance and adhesion do not predict their in vivo residence

    Get PDF
    The in vivo residence of nail lacquers (which are ideal topical drug carriers for the treatment of nail diseases) determines their frequency of application, and is thereby expected to influence patient adherence and success of treatment. Thus in vitro measurements to indicate lacquers’ in vivo residence are routinely conducted during formulation development. However the literature on in vitro-in vivo correlations is severely limited. Thus, the aim of the work discussed in this paper was to investigate correlations between in vivo residence and in vitro film resistance to water, in vitro film adhesion and surface energy of lacquer films. In vivo measurements were conducted on fingernails in six volunteers. Seven commercially available nail lacquers were tested in commonly-used measurements. Correlations between in vivo residence and in vitro water resistance and adhesion were found to be extremely poor. The surface energies of the lacquer films (which were between 33 and 39 mJ/m2) were also not predictive of in vivo residence. High density polyethylene (HDPE) sheet – whose surface energy was determined to be similar to that of the human nailplate – was found to be a suitable model for the nailplate (when investigating surface energy) and was used in a number of experiments

    Ethnic Inequalities in Psychological Distress : A Population Data Linkage Study on the Pacific Island of Guåhån/Guam

    Get PDF
    Psychological distress and mental illness has been found to be elevated in migrant groups living in sovereign countries, as well as for indigenous people living under colonial or administrative rule. The north Pacific island of Guam is unusual in its ethnic composition as it has no majority ethnic group, has a large indigenous population and remains a territory of the U.S. This study aimed to identify ethnic differences in self-reported psychological distress between the main ethnic groups on Guam. The study uses a cross sectional design with data linkage methodology, drawing on the Guam Census and the Behavioral Risk Factor Surveillance System health survey for Guam. The results showed that the native Chamorro population had worse self-reported psychological distress (defined as a ‘mental health condition or emotional problem’) than White/Caucasians (OR 2.09, 95% CI 1.52–2.87), particularly for severe distress (OR 3.61, 95% CI 1.33–2.77). This relationship persisted even after adjusting for a wide range of socio-demographic and economic factors (OR 2.58, 95% CI 1.15–5.76). Other Pacific Islanders also had higher psychological distress compared to White/Caucasians, but this association was largely explained by the adjusted factors. The findings are discussed in terms of social and economic disadvantage for Pacific Island peoples on Guam, as well as the impact of colonial administration, disaffection, and lack of autonomy for the Chamorro of Guam. Recommendations are made to improve psychiatric treatment for these groups by considering wider socio-political factors in assessment and treatment, as well as broader implications for the national dialogue on self-determination.Peer reviewe
    • …
    corecore