111 research outputs found

    Benchmarking the Minimum Electron Beam (eBeam) Dose Required to Achieve Sterility of Space Foods

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    The safety, nutrition, acceptability, and shelf life of space foods are of paramount importance to NASA, especially on long-duration missions. Since food and mealtimes play a key role in reducing stress and boredom of prolonged missions, the acceptability of food in terms of appearance, flavor, texture and aroma can have significant psychological ramifications on astronaut performance. The FDA, which oversees space foods, currently requires a minimum dose of 44 kGy for irradiated space foods. The underlying hypothesis is that commercial sterility of space foods could be achieved at significantly lower doses. Lowering the minimum dose can positively impact the visual appearance, sensory attributes, nutrient content, and overall acceptability of space foods. The focus of this project was to use beef fajitas (an example NASA space food) and employ eBeam processing to benchmark the minimum eBeam dose required for sterility. A 15 kGy dose was able to achieve an approximately 10 log reduction in STEC bacteria, and 5 log reduction in Clostridium sporogenes spores. Furthermore, accelerated shelf life testing (ASLT) to determine sensory and quality characteristics under various conditions was conducted. Using GC/MS-olfactory analysis, numerous volatiles were shown to be dependent on the dose applied to the product. Furthermore, concentrations of off –flavor aroma compounds such as dimethyl sulfide were decreased at the reduced 15 kGy dose. The long-term goal of this project is to collect empirical data to enable NASA to petition the FDA to lower the minimum dose from 44 kGy to significantly lower doses

    Quantitative comparisons on hand motor functional areas determined by resting state and task BOLD fMRI and anatomical MRI for pre-surgical planning of patients with brain tumors

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    AbstractFor pre-surgical planning we present quantitative comparison of the location of the hand motor functional area determined by right hand finger tapping BOLD fMRI, resting state BOLD fMRI, and anatomically using high resolution T1 weighted images. Data were obtained on 10 healthy subjects and 25 patients with left sided brain tumors. Our results show that there are important differences in the locations (i.e., >20mm) of the determined hand motor voxels by these three MR imaging methods. This can have significant effect on the pre-surgical planning of these patients depending on the modality used. In 13 of the 25 cases (i.e., 52%) the distances between the task-determined and the rs-fMRI determined hand areas were more than 20mm; in 13 of 25 cases (i.e., 52%) the distances between the task-determined and anatomically determined hand areas were >20mm; and in 16 of 25 cases (i.e., 64%) the distances between the rs-fMRI determined and anatomically determined hand areas were more than 20mm. In just three cases, the distances determined by all three modalities were within 20mm of each other. The differences in the location or fingerprint of the hand motor areas, as determined by these three MR methods result from the different underlying mechanisms of these three modalities and possibly the effects of tumors on these modalities

    Benchmarking the Minimum Electron Beam (eBeam) Dose Required to Achieve Sterility of Space Foods

    Get PDF
    The safety, nutrition, acceptability, and shelf life of space foods are of paramount importance to NASA, especially on long-duration missions. Since food and mealtimes play a key role in reducing stress and boredom of prolonged missions, the acceptability of food in terms of appearance, flavor, texture and aroma can have significant psychological ramifications on astronaut performance. The FDA, which oversees space foods, currently requires a minimum dose of 44 kGy for irradiated space foods. The underlying hypothesis is that commercial sterility of space foods could be achieved at significantly lower doses. Lowering the minimum dose can positively impact the visual appearance, sensory attributes, nutrient content, and overall acceptability of space foods. The focus of this project was to use beef fajitas (an example NASA space food) and employ eBeam processing to benchmark the minimum eBeam dose required for sterility. A 15 kGy dose was able to achieve an approximately 10 log reduction in STEC bacteria, and 5 log reduction in Clostridium sporogenes spores. Furthermore, accelerated shelf life testing (ASLT) to determine sensory and quality characteristics under various conditions was conducted. Using GC/MS-olfactory analysis, numerous volatiles were shown to be dependent on the dose applied to the product. Furthermore, concentrations of off –flavor aroma compounds such as dimethyl sulfide were decreased at the reduced 15 kGy dose. The long-term goal of this project is to collect empirical data to enable NASA to petition the FDA to lower the minimum dose from 44 kGy to significantly lower doses

    Space Dependent Study of Fast Neutron Spectra and Tritium Production Rate in a Fusion Reactor Blanket of Li₂O

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    Study of spatial spectra and tritium breeding ratio (TBR) in a lithium blanket play a crucial role for the successful operation of a Fusion reactor. In this paper, we have reported the results for the space-dependent fast neutron spectra and tritium production rate (TPR) in cylindrical assemblies of Li₂O. The multigroup diffusion equation has been solved using eigenfunction expansion method. The obtained results for scalar spectra, total flux and TPR in Li₂O are compared with corresponding values for natural Li. The space dependent scalar spectrum in Li₂O has been compared for different configurations (slab, sphere and cylindrical). We find that the shapes of the curves are almost similar, though the neutron flux is found to be highest in the case of cylindrical assembly. This suggests a larger value of total TBR for a cylindrical geometry. Further, the study of space variation of total flux for Li₂O and natural Li shows that there is not much change in the shapes and numerical values, however, it falls sharply near the boundary end surface of the assembly for Li₂O as compared to natural Li. Similarly, the fall in the TPR curves becomes more rapid for the case of Li₂O as compared to natural Li near the boundary end.. The calculated results of spatial distributions of TPR for 6Li (n,α)t and ⁷Li (n,n'α)t reactions are compared with experimentally obtained results for cylindrical slab assemblies. and it is found that agreement is fairly good, both in the case of 7Li and 6Li

    An Empirical Study to Measure Customer Experience for Telecom Operators in Indian Telecom Industry

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    as Indian Telecom industry matures itself, service providers understand the essence of Customer Experience as the prime differentiator towards business success. This paper will provide a rundown of the extant literature on customer experience studies done in Telecom industry. This research paper also attempts to identify the determinants of Customer Experience for Telecom operators in Indian Telecom industry. Also this research paper defines a yardstick called ACEI score to quantify customer experience in telecom industr

    Glioblastoma Survival Outcomes at a Tertiary Hospital in Appalachia: Factors Impacting the Survival of Patients Following Implementation of the Stupp Protocol

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    Glioblastoma is a fatal brain cancer with low median and yearly survival rates. The standard of care for treating glioblastoma is gross total resection (GTR) coupled with the Stupp protocol, but various factors influence the interventions undertaken and survival achieved. As health disparities exist in rural areas, survival in these areas need to be assessed in order to understand which factors detract from the successes of these standard medical interventions. We retrospectively determined the impact of age of diagnosis, number of lesions, the molecular marker O6-methylguanine methyltransferase (MGMT), extent of surgery, and completion of the Stupp protocol on survival among patients treated at West Virginia University Hospitals. We found that an age of diagnosis under 60 years, having the MGMT gene methylated, having a unifocal tumor, receiving GTR, adhering to the Stupp protocol, and undergoing a treatment course of GTR followed by the Stupp protocol significantly increased survival. Lastly, we compared our findings to a pre-Stupp study done in West Virginia in 1996. This comparison showed that although overall median survival has not increased, all interventions involving GTR have resulted in a significantly higher survival. We conclude that we can serve our patient population by offering GTR to all adult glioblastoma patients when no contraindications exist and ensuring that patients follow the Stupp protocol. After discharge, the Stupp protocol may not be followed/completed for a variety of reasons. In the future, we aim to assess these reasons and analyze other significant interventional and socioeconomic factors which influence survival

    Efficacy of Stereotactic Radiosurgery in Patients with Multiple Metastases: Importance of Volume Rather Than Number of Lesions

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    The role of stereotactic radiosurgery (SRS) in the treatment of multiple brain metastases is controversial. While whole brain radiation therapy (WBRT) has historically been the mainstay of treatment, its value is increasingly being questioned as emerging data supports that SRS alone can provide comparable therapeutic outcomes for limited (one to three) intracranial metastases with fewer adverse effects, including neurocognitive decline. Multiple recent studies have also demonstrated that patients with multiple (\u3e 3) intracranial metastases with a low overall tumor volume have a favorable therapeutic response to SRS, with no significant difference compared to patients with limited metastases. Herein, we present a patient with previously controlled breast cancer who presented with multiple recurrences of intracranial metastases but low total intracranial tumor volume each time. This patient underwent SRS alone for a total of 40 metastatic lesions over three separate procedures with good local control and without any significant cognitive toxicity. The patient eventually opted for enrollment in the NRG-CC001 clinical trial after multiple cranial recurrences. She received conventional WBRT with six months of memantine and developed significant neurocognitive side effects. This case highlights the growing body of literature supporting the role of SRS alone in the management of multiple brain metastases and the importance of maximizing neurocognition as advances in systemic therapies prolong survival in Stage IV cancer

    Biology and damage of Asian walnut moth, Garella musculana (Lepidoptera: Nolidae), a major insect pest of Juglans regia in Kashmir Himalaya

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    Over past two decades, Garella musculana (Erschoff, 1874) (Lepidoptera: Nolidae) has surged as a prominent pest in Eurasia infesting Juglans regia. Its caterpillar causes an extensive damage to young fruits and shoots of natural and cultivated varieties of J. regia. The larval instars were seen feeding on nuts from May to August. In August, they start leaving nuts for pupation to continue life cycle next year. The pupation took place inside the loose bark or crevices of walnut trees in white cocoons. In this study life cycle and extent of damage was studied. The larva goes through five growth stages (instars) and lasts for about 67.1±2.26 days. It overwinters in the pupal stage in a white dense cocoon and then emerges in spring as adult when environment becomes favourable. The mean generation time was 297.5±4.45 days. It is univoltine in nature and its larva consumes young walnut pericarp resulting in deformed nuts and there early fall leading to substantial yield loses. The deposition of excrement by larva of G. musculana on the outer green thick layer (husk) degrades its quality and thereby reduces the economic value of the walnut. Knowledge of life-history is crucial for the design of management strategies. The management possibilities of this pest are limited as the feeding destructive larvae are present within the shell or nut. Understanding the life cycle is important to spray timing and effective control. The emergence of the pest and egg laying are important attributes in controlling this pest. Besides natural enemies as eco-friendly approaches acting as bio control agents are encouraged as the most viable alternative for management of this insect pest in this particular area. It is also important to promote the development of new walnut cultivars in newly planted walnut orchards with high potential output and higher shelling percentages

    Paradoxical euthyroid hormone profile in a case of Graves' disease with cardiac failure

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    Cardiac failure is an uncommon complication of juvenile hyperthyroidism. We describe an adolescent boy with Graves' disease who developed manifestations of heart failure while on antithyroid medications. There was no evidence of any underlying cardiac disease. He had paradoxical euthyroid hormone profile which rose to hyperthyroid range when the manifestations of the cardiac failure subsided. The case highlights several unusual features of Graves' disease
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