Evolving Spectra of Pop III Stars: Consequences for Cosmological Reionization

We examine the significance of the first metal-free stars (Pop III) for the cosmological reionization of HI and HeII. These stars have unusually hard spectra, with the integrated ionizing photon rates from a Pop III stellar cluster for HI and HeII being 1.6 and $10^5$ times stronger respectively than those from a Pop II cluster. For the currently favored cosmology, we find that Pop III stars alone can reionize HI and HeII at redshifts, $z$ of about 9 (4.7) and 5.1 (0.7) for continuous (instantaneous) modes of star formation. More realistic scenarios involving combinations of Pop III and Pop II stellar spectra yield similar results for hydrogen. Helium never reionizes completely in these cases; the ionization fraction of HeIII reaches a maximum of about 60 percent at $z$ of about 5.6 if Pop III star formation lasts for $10^9$ yr. Future data on HI reionization can test the amount of small-scale power available to the formation of the first objects, and provide a constraint on values of $\sigma_8$ less than or about 0.7. Since current UV observations indicate an epoch of reionization for HeII at $z$ of about 3, HeII may reionize more than once. Measurements of the HeII Gunn-Peterson effect in the intergalactic medium at redshifts exceeding about 3 may reveal the significance of Pop III stars for HeII reionization, particularly in void regions that may contain relic ionization from early Pop III stellar activity.Comment: 29 pages, 4 figures. Accepted for publication in Ap.J. (Feb. 20, 2003 issue; v. 584); minor revisions, results unchange

A Prospective study to compare T2 Weighted MRI to CT imaging in volume delineation for radiotherapy planning in carcinoma cervix

OBJECTIVES: To compare magnetic resonance imaging (MRI), computed tomography (CT), and clinical examination to evaluate the impact of MRI on target volume delineation as compared to the volumes obtained on a CT scan and also to see the effect on staging and prognosis. METHODS: Twenty patients diagnosed with locally advanced carcinoma cervix underwent planning CT abdomen and pelvis which was fused with T2 weighted MRI images to evaluate the impact of MRI on target volume delineaton , to see if CT scan along with clinical findings can be a good alternate to MRI scan.A descriptive analysis and frequency distribution of the patient characteristics was done. Fisher's exact test was done to find out relationship between prognostic factors and image findings. PABAK was done to compare different imaging modalities (CT versus MRI).Paired T test was used for tumor volume comparison. RESULTS: MRI was better in tumor delineation as compared to CT scan. Additional imaging gave information regarding local extent of the disease, nodal involvement . Upstaging of disease helped in selecting appropriate treatment modality. CONCLUSION: Though the findings on CT, MRI, or PET examinations are not mandatory for FIGO staging it could be of additional benefit and provide extra information that would result in stage migration, help appropriate selection of treatment modality,result in more accurate radiotherapy treatment planning and also provide prognostic information that would impact on the outcome of treatment and survival. CT with good clinical examination could be used as an alternate to MRI where MRI is not feasible

Spectral Clustering with Jensen-type kernels and their multi-point extensions

Motivated by multi-distribution divergences, which originate in information theory, we propose a notion of `multi-point' kernels, and study their applications. We study a class of kernels based on Jensen type divergences and show that these can be extended to measure similarity among multiple points. We study tensor flattening methods and develop a multi-point (kernel) spectral clustering (MSC) method. We further emphasize on a special case of the proposed kernels, which is a multi-point extension of the linear (dot-product) kernel and show the existence of cubic time tensor flattening algorithm in this case. Finally, we illustrate the usefulness of our contributions using standard data sets and image segmentation tasks.Comment: To appear in IEEE Computer Society Conference on Computer Vision and Pattern Recognitio

Shadows of Time: Content creation for the Performance art installation

Shadows of Time is a non-linear narrative video installation which would be used as a backdrop for the larger performance event. The content creation for the performance was undergone a series of process to achieve the style which was decided by the team. The installation will showcase only the photographs of architectural details of Tombs which would depict symbolically the different phases of her life such as Hayat Bakshi’s timeline, her husband’s death, her thoughts about future following her death and finally showcasing the present scenario. In the process, I explored various style of image processing, methods and processes of filmmaking, different kind of treatments in order to achieve the required output as per the decided framework. The result is an eight-minute video narrative projection without dialogues along with the composed music and set design. The final installation event would be a collaboration with the performance artists along with other interactive installations contributed by other members in the team

Pedestrian Flow Characteristics at Upstream and Downstream of Bottleneck for Unidirectional Flow under Normal Conditions

The study of pedestrian flow characteristics at upstream and downstream of bottlenecks is important from level of service and evacuation perspective. Many controlled laboratory experiments have been conducted to study pedestrians’ behavior at bottlenecks. However, it is unclear whether experiments can reproduce real crowd flow characteristics. In this paper, real field data was collected at normal conditions for unidirectional pedestrian movement at Mahakaleshwar, a Hindu temple at Ujjain, India during Mahashivaratri, a festival day on which a large number of pilgrims visited the temple. Along the corridor there is a width reduction at a U-turn which creates a bottleneck. It is necessary to study pedestrian flow characteristics at bottlenecks to ensure desired level of service at temple premises during heavy flow. The speed-density relationships of upstream and downstream sections were compared and it was found that flow behavior at both the sections of bottleneck severely differ from each other. Pedestrians in the upstream are either at free flow speed for very low density values or moving slowly for intermediate to high range of density values. From the speed-density relationship, it can be concluded that pedestrians at upstream had visual clues of congestion ahead at bottleneck (pedestrian could also see the downstream flow through barricades). Therefore, pedestrians wait at their position, stay in their comfort zone and do not push each other. Thus, even at intermediate local density, pedestrians have such low speeds. This violates the general assumption that pedestrians change their speed only at the shockwave boundary. The movement of pedestrians at upstream is governed by local density and information of congestion status ahead, whereas pedestrian movement at downstream is governed by factors like density, side friction and pedestrians’ willingness to compensate for the delay at bottleneck. This study is expected to have application in planning and operation of pedestrian facilities

Determination of pedestrian’s personal space in mass religious gatherings - A case study of Kumbh Mela

Personal space can be defined as the physical distance between two individuals in a social environment. It varies from person to person depending on culture and context and there are significant individual differences too. Studying personal space includes the ability to recognize the various zones of involvement and the activities, relationships, and emotions associated with each zone. This paper tries to formulate and define personal space in high density crowd situations in Kumbh Mela, one of the world’s largest mass religious gatherings. Video data of pilgrims taking part in the Panchkroshi Yatra, a religious walkathon which is a part of KumbhMela, is used for the analysis of factors affecting personal space. To identify the thresholds of personal space, walking speed of individuals, gender, presence of luggage and the number of males and females surrounding an individual have been considered. It is found that the average speed of the individual, the group size,and the gender ratio of group members have a significant effect on the personal space of an individual. Also, it is observed that the personal space follows an asymmetrical pattern rather than a symmetrical pattern

Preparation and Characterization of CuO Nanoparticles by Novel Sol-Gel Technique

Recent developments of nanosize materials of metal and metal oxide particles are intensively pursued because of their prominence in different fields of applications. Among all the transition metal oxides, CuO is a potential candidate for the application of magnetic storage devices, solar energy transfer, sensors, and super capacitors etc. Moreover CuO nanoparticles act as a good catalyst in some of the chemical reactions. CuO nanoparticles were prepared by novel sol-gel method. In this technique CuCl2.6H2O is added with acetic acid and heated to 100 °C with continuous stirring. To control the ph of the above solution, NaOH is added to the solution till ph reached desired value. The color of the solution changed from blue to black with precipitation. The black precipitation was washed 3 – 4 times with distilled water. Finally the solution was centrifuged and dried in air for one day. The CuO nanoparticles were characterized by studying their structure with X-ray diffraction and composition by energy dispersive X-ray analysis. The size of the nanoparticles is estimated by particle size analyzer and transmission electron microscopy. The optical studies were carried out with Uv-Vis spectrophotometer. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2960

Adult chordoid meningioma: a case report

Chordoid meningioma is a rare tumour accounting for less than 0.5% of all meningiomas. It is a WHO grade II tumour with an aggressive behavior. It is a rare variant characterized by cords or trabeculae of eosinophilic or vacuolated cells set in an abundant mucoid matrix. It can be associated with systemic or hematologic manifestations like Castleman disease. The tumor has a propensity for aggressive behavior and increased likelihood of recurrence We report a case of an adult patient with chordoid meningioma who presented with headache and seizures and did not have any hematological/ systemic manifestations. She underwent total excision of the lesion and is doing well

Efficacy of cartridge based nucleic acid amplification test to diagnose tubercular pleural effusion

Background: Tuberculosis (TB) remains a major health concern worldwide. Extra pulmonary tuberculosis (EPTB) in India accounts up to 20% of all tuberculosis cases. EPTB often remains undetected and untreated due to variable clinical presentation and lack of diagnostic means. Early detection of TB and drug resistance is important in the management of TB. The aim of present study was to assess the role of cartridge based nucleic acid amplification test in rapid diagnosis of tubercular pleural effusion.Methods: The study screened 211 symptomatic patients. The patients with clinical and radiological presentations suggestive of pleural effusion were analyzed using light’s criteria to make a diagnosis of tubercular pleural effusion; these patients submitted pleural fluid sample for smear microscopy after concentration for presence of acid fast bacilli under light emitting diode based fluorescent microscopy (LED-FM), and for cartridge based nucleic acid amplification test (CBNAAT) using GX4 GeneXpert MTB/Rif test system. The results were statistically analyzed.Results: Out of patients who had pleural effusion without any pulmonary tuberculosis, pleural fluid biochemistry analyses using light’s criteria detected 20 tubercular pleural effusions (11 male and 9 female). Seven patients had history of extrapulmonary tuberculosis in past, all of them received treatment with effective treatment compliance in past. Pleural fluid microscopic examination for detection of acid-fast bacilli was not able to detect acid-fast bacilli in any of these 20 patients diagnosed with tubercular pleural effusion. CBNAAT could authentically detect M. tuberculosis in 5/20 patients diagnosed with tubercular pleural effusion. There was no impact of gender, previous history of tuberculosis, history of anti-tuberculosis treatment (ATT) intake, or compliance to ATT on CBNAAT status in this study.Conclusions: CBNAAT has the potential to significantly authenticate tubercular etiology in some of smear-negative pleural fluid specimens with rapid test results. It has an added advantage to assess the rifampicin drug sensitivity. All this contribute hugely in diagnosis and management of tubercular pleural effusion