Adaptive Estimation of Line-of-sight Rate Measurement from a Radio Frequency Seeker

The line-of-sight (LOS) rate output from a radio frequency (RF) seeker is widely used during the homing phase guidance of a tactical missile: The LOS rate is noisy and needs to be filtered.The application of an adaptive Kalman filter for the L.OS rate state estimation has been studied. This filter requires minimal a priori knowledge about technical parameters of the seeker. It isalso capable of estimating the variable noise statistics

Hypercalcemia Associated with a Malignant Brenner Tumor Arising from a Mature Cystic Teratoma

A 60-year-old woman presented with abdominal pain and weight loss and was found to have serum calcium of 15.0 mg/dl. Serum parathyroid hormone-related peptide (PTHrP) returned elevated. Imaging suggested bilateral mature cystic teratomas. Her hypercalcemia was treated initially with intravenous saline, as well as intramuscular and subcutaneous calcitonin. She underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy, and final pathology revealed malignant Brenner tumor in association with a mature cystic teratoma. Her postoperative PTHrP returned less than assay, and her total and ionized calcium fell below normal, requiring supplemental calcium and vitamin D. At follow-up one month after discharge, her calcium had normalized. We present the first reported case of hypercalcemia occurring in association with a malignant Brenner tumor. Malignancy-associated hypercalcemia occurs via four principal mechanisms: (1) tumor production of PTHrP; (2) osteolytic bone involvement by primary tumor or metastasis; (3) ectopic activation of vitamin D to $1,25-(OH)_2$ vitamin D, and (4) ectopic production of parathyroid hormone. PTHrP-mediated hypercalcemia is the most common mechanism and was responsible in this case. In patients with paraneoplastic hypercalcemia who undergo surgical treatment, close monitoring and management of serum calcium is necessary both pre- and postoperatively

Assessing the Impacts of Climate Change on Crop Yields in Different Agro-climatic Zones of India

The study attempts to estimate and predict climate impact on crop yields using future temperature projections under two climate emissions scenarios of RCP 4.5 and 8.5 for three different time periods (2030s, 2050s and 2080s) across Agro-climatic zones (ACZ) of India. During the period 1966-2011, a significant rise was observed in both the annual mean maximum and minimum temperature across ACZs. Rainfall recorded an annual decline in Himalayan Regions and Gangetic Plains and a rise in Coastal Regions, Plateau & Hills and Western Dry Region. Our results showed high heterogeneity in climate impact on kharif and rabi crop yields (with both negative and positive estimates) across ACZs. It was found that rainfall had a positive effect on most of crop yields, but was not sufficient enough to counterbalance the impact of temperature. Changes in crop yield were more pronounced for higher emission scenario of RCP 8.5. Thus, it was evident that the relative impacts of climate change and the associated vulnerability vary by ACZs, hence comprehensive crop and region-specific adaptation measures should be emphasized that helps in enhancing resilience of agricultural system in short to medium term

Predicting postoperative systolic dysfunction in mitral regurgitation: CT vs. echocardiography

IntroductionVolume overload from mitral regurgitation can result in left ventricular systolic dysfunction. To prevent this, it is essential to operate before irreversible dysfunction occurs, but the optimal timing of intervention remains unclear. Current echocardiographic guidelines are based on 2D linear measurement thresholds only. We compared volumetric CT-based and 2D echocardiographic indices of LV size and function as predictors of post-operative systolic dysfunction following mitral repair.MethodsWe retrospectively identified patients with primary mitral valve regurgitation who underwent repair between 2005 and 2021. Several indices of LV size and function measured on preoperative cardiac CT were compared with 2D echocardiography in predicting post-operative LV systolic dysfunction (LVEFecho <50%). Area under the curve (AUC) was the primary metric of predictive performance.ResultsA total of 243 patients were included (mean age 57 ± 12 years; 65 females). The most effective CT-based predictors of post-operative LV systolic dysfunction were ejection fraction [LVEFCT; AUC 0.84 (95% CI: 0.77–0.92)] and LV end systolic volume indexed to body surface area [LVESViCT; AUC 0.88 (0.82–0.95)]. The best echocardiographic predictors were LVEFecho [AUC 0.70 (0.58–0.82)] and LVESDecho [AUC 0.79 (0.70–0.89)]. LVEFCT was a significantly better predictor of post-operative LV systolic dysfunction than LVEFecho (p = 0.02) and LVESViCT was a significantly better predictor than LVESDecho (p = 0.03). Ejection fraction measured by CT demonstrated significantly greater reproducibility than echocardiography.DiscussionCT-based volumetric measurements may be superior to established 2D echocardiographic parameters for predicting LV systolic dysfunction following mitral valve repair. Validation with prospective study is warranted

Blood pool contrast agents for venous magnetic resonance imaging

Imaging of the venous system plays a vital role in the diagnosis and management of a wide range of clinically significant disorders. There have been great advances in venous imaging techniques, culminating in the use of magnetic resonance venography (MRV). Although MRV has distinct advantages in anatomic and quantitative cross sectional imaging without ionizing radiation, there are well-known challenges in acquisition timing and contrast administration in patients with renal impairment. The latest advancement involves the addition of new contrast media agents, which have emerged as valuable alternatives in these difficult scenarios. In this review, we will focus on a group of specific contrast agents called blood pool agents and discuss their salient features and clinical applications

Power Amplifier Characteristic-Aware Energy-Efficient Transmission Strategy ⋆

Abstract. The energy consumption in transmitting an information bit, i.e., energy-per-bit, has been known to decrease monotonically as the transmission time increases [1]. However, when considering the power amplifier (PA) characteristics, we learn that the energy-per-bit starts to increase as the transmission time becomes long over a certain threshold. This is caused by the fact that, in a wireless device, it is not the transmission power, which determines the energy consumed during transmissions, but the input power to the PA whose output power is used as the transmission power. Based on our new trade-off model between the energy-per-bit and transmission time, we revisit known energy-efficient scheduling algorithms. Finally, we evaluate the impact of the new tradeoff model and the performance of algorithms via simulations.

Magnetic Resonance Imaging Utilization in an Emergency Department Observation Unit

Introduction: Emergency department observation units (EDOUs) are a valuable alternative to inpatient admissions for ED patients needing extended care. However, while the use of advanced imaging is becoming more common in the ED, there are no studies characterizing the use of magnetic resonance imaging (MRI) examinations in the EDOU. Methods: This institutional review board-approved, retrospective study was performed at a 999-bed quaternary care academic Level I adult and pediatric trauma center, with approximately 114,000 ED visits annually and a 32-bed adult EDOU. We retrospectively reviewed the EDOU patient database for all MRI examinations done from October 1, 2013, to September 30, 2015. We sought to describe the most frequent uses for MRI during EDOU admissions and reviewed EDOU length of stay (LOS) to determine whether the use of MRI was associated with any change in LOS. Results: A total of 22,840 EDOU admissions were recorded during the two-year study period, and 4,437 (19%) of these patients had a least one MRI examination during their stay; 2,730 (62%) of these studies were of the brain, head, or neck, and an additional 1,392 (31%) were of the spine. There was no significant difference between the median LOS of admissions in which an MRI study was performed (17.5 hours) and the median LOS (17.7 hours) of admissions in which an MRI study was not performed [p=0.33]. Conclusion: Neuroimaging makes up the clear majority of MRI examinations from our EDOU, and the use of MRI does not appear to prolong EDOU LOS. Future work should focus on the appropriateness of these MRI examinations to determine potential resource and cost savings

Magnetic Resonance Imaging Utilization in an Emergency Department Observation Unit

Introduction Emergency Department Observation Units (EDOUs) are a valuable alternative to inpatient admissions for Emergency Department (ED) patients needing extended care. However, while the use of advanced imaging is becoming more common in the ED, there are no studies characterizing the use of magnetic resonance imaging (MRI) examinations in the EDOU. Methods This Institutional Review Board-approved, retrospective study was performed at a 999-bed quaternary care academic Level 1 adult and pediatric trauma center, with approximately 114,000 ED visits annually and a 32-bed adult EDOU. The EDOU patient database was retrospectively reviewed for all MRI examinations done from October 1st, 2013 to September 30th, 2015. We sought to describe the most frequent uses for MRI during EDOU admissions and reviewed EDOU length of stay (LOS) to determine whether the use of MRI was associated with any change in LOS. Results 22,840 EDOU admissions were recorded during the two-year study period, and 4,437 (19%) of these patients had a least one MRI examination during their stay. 2,730 (62%) of these studies were of the brain, head, or neck and an additional 1,392 (31%) were of the spine. There was no significant difference between the median LOS of admissions in which an MRI study was performed (17.5 hours) and the median LOS (17.7 hours) of admissions in which an MRI study was not performed [p=0.33]. Conclusion Neuroimaging makes up the clear majority of MRI examinations from our EDOU, and the use of MRI does not appear to prolong EDOU LOS.  Future work should focus on the appropriateness of these MRI examinations to determine potential resource and cost savings