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Although poor precipitation due to delayed arrival and/or early retreat of the southwest monsoon is considered the chief architect of drought in India, heat waves may also play a crucial role in the intensification of droughts. In the Indian subcontinent, occurrence of heat waves during the pre-monsoon and high air-temperature in the subsequent monsoon season imparts thermal stress on vegetation causing degradation of vegetation health (VH). In the present study, various vegetation indices and land-use/land-cover data derived from multi-sensor satellite have been used to assess VH and agricultural drought in Gujarat during 1981–2010. This Geographical Information Systems-based study has also used heat wave and temperature data to analyze the adverse effects of high temperature on VH. The time series of Vegetation Condition Index and Temperature Condition Index (TCI) has shown that the combined influence of moisture-stress and thermal stress determines the occurrence and severity of drought, which is reflected in the Vegetation Health Index (VHI). A strong correlation among aboveground air-temperature, the TCI and the VHI indicates definite influence of thermal stress on VH. Further, a systematic variation and strong resemblance between temperature, crop yield, TCI and VHI has established the impact of thermal stress on agricultural productivity.

Patellofemoral pain syndrome (PFPS) is one of the most common causes of anterior knee pain in active populations. Due to its multifactorial nature, patellofemoral pain is hard to diagnose and treat. Increased stress in the subchondral bone is associated with PFPS and is correlated to elevated bone remodelling. [18F]NaF PET-MR imaging can localize regions of elevated bone remodelling and provide information about the metabolic processes involved (1, 2). Further, [18F]NaF uptake changes after exercise, thus showing that it is sensitive to changes in bone physiology resulting from acute bone loading (3, 4). For cartilage, T2 relaxation times have been used to study cartilage hydration and microstructure changes after exercise. While some studies have observed a decrease in T2 times after exercise, changes are usually transient and have largely been evaluated in the context of healthy subjects (5). An early sign of persistent abnormal mechanical stress is Bone Marrow Lesions (BMLs), which are strongly associated with pain and structural disease progression. We aimed to reproduce prior work which has shown that acute loading results in a large physiological response in bone regions with BMLs. Further, we wanted to explore if there is breakdown of the cartilage microstructure, either at baseline or in response to loading in cartilage regions adjacent to BMLs. The purpose of this study is to detect changes in the functional response of the knee joint to loading using [18F]NaF PET-MR imaging after a stair-climbing exercise in subjects with unilateral patellofemoral pain.

Conventional knee MRI protocols use numerous 2D FSE sequences with multiple contrasts, often repeated in multiple scan planes. This approach requires long scan times and does not fully utilize modern reconstruction, 3D, acceleration, and improved coil SNR technologies. Numerous approaches have been proposed to improve the value of knee imaging by reducing protocol times to less than 6 minutes and perhaps adding utility through quantitative data or oblique reformats. In this abstract, we present preliminary data and outline four such approaches: (1) an accelerated conventional 2D protocol; (2) a SNR-efficient 3D qDESS protocol, (3) a CUBE protocol, and (4) a thin-slice protocol with high resolution and compare them to a standard knee protocol.

The Osteoarthritis Initiative was a longitudinal study of osteoarthritis that prospectively collected a trove of imaging data including Multi-Echo Spin-Echo (MESE) data for cartilage T2 relaxation time assessment in one knee. While this data remains underutilized, several analyses have been performed over the past years to assess T2 sensitivity to OA exploiting the OAI dataset. However, fitting procedures to compute T2 maps from the MESE data in the OAI largely rely on mono-exponential modelling, which is inherently sub-optimal as it does not account for stimulated echoes produced by RF slice-profile and B1 inhomogeneities and it often fails to account for low SNR in longer TEs. To mitigate errors, a common practice is to drop the first echo and fit the remaining 6 echoes at the expense of discarding information and degrading SNR efficiency. T2 fitting of MESE data using Extended phase graph (EPG) modelling, whether based on nonlinear least square (NLSQ) dictionary matching (DM) or deep learning (DL), can account for stimulated echoes, and can potentially provide more accurate and robust fitting for T2mapping in the OAI.

The recently proposed B-Score uses statistical shape models (SSM) to represent femur shape as a scalar value similar to the osteoporosis T-score. The B-Score quantifies OA bone shape and is defined as the distance from the mean healthy bone shape (B-Score=0) to the mean OA bone shape, where 1-unit is equal to the standard deviation of the healthy B-Scores [Bowes et al. 2021]. However, SSMs require finding matching points between subjects’ femurs, and learn linear features, potentially limiting their ability to capture physiologic shape. Neural Shape Models (NSM) have been shown to represent object surfaces without requiring matching points between subjects using non-linear neural networks. Here, we use NSMs to reconstruct bone shapes and use these features to encode information about OA.

On June 15,1991 the Mt. Pinatubo volcano had a major eruption that injected a considerable amount of dust, ash, and sulfur dioxide gas into the atmosphere. This volcanic cloud blocked the amount of energy reaching the Earth's surface causing, in turn, a decrease in NDVI values specifically in the tropics. Estimates have been made which showed changes in NDVI during pre- and post-Pinatubo periods. Two-three weeks after the Mt. Pinatubo eruption the NDVI started to decrease, progressing until fall 1991. After that period, a gradual recovery of NDVI was observed, resulting from a diminishing of aerosol optical thickness.

NDVI (Normalized Difference Vegetation Index) images generated from NOAA AVHRR GVI data were recently used to monitor large scale drought patterns and their climatic impact on vegetation. The purpose of this study is to use the Vegetation Condition Index (VCI) to further separate regional NDVI variation from geographical contributions in order to assess regional drought impacts. Weekly NDVI data for the period of July 1985 to June 1992 were used to produce NDVI and VCI images for the South American continent. NDVI data were smoothed with a median filtering technique for each year. Drought areas were delineated with certain threshold values of the NDVI and VCI. Drought patterns delineated by the NDVI and VCI agreed quite well with rainfall anomalies observed from rainfall maps of Brazil. NDVI values reflected the different geographical conditions quite well. Seasonal and interannual comparisons of drought areas delineated by the VCI provided a useful tool to analyse temporal and spatial evolution of regional drought as well as to estimate crop production qualitatively. It is suggested that VCI data besides NDVI may be used to construct a large scale crop yield prediction model.

Successful application of the normalized difference vegetation index (NDVI) for estimating weather impacts on vegetation is currently hindered in non-homogeneous areas. The problem is that the differences between the level of vegetation in these areas can be related, in addition to weather impacts, to the differences in geographic resources (climate, soil, vegetation type and topography). These differences should be eliminated when weather impacts on vegetation are estimated from NDVI data. This paper discusses a concept and a technique for eliminating that portion of the NDVI which is related to the contribution of geographic resources to the amount of vegetation. The Advanced Very High Resolution Radiometer (AVHRR) data of the Global Vegetation Index format were used for the 1984-1987 seasons in Sudan. The procedure suggests normalization of NDVI values relative to the absolute maximum and the absolute minimum of NDVI. These two criteria were shown to be an appropriate characteristic of geographic resources of an area. The modified NDVI was named the Vegetation Condition Index (VCI). Comparison between VCI, NDVI and precipitation dynamics showed that the VCI estimates better portray precipitation dynamics as compared to the NDVI. The VCI permits not only the desciption of vegetation but also estimation of spatial and temporal vegetation changes and weather impacts on vegetation.

In a 6-month, double-blind, placebo-controlled study, 1100 to 150 mg/d indomethacin appeared to protect mild to moderately impaired Alzheimer's disease patients from the degree of cognitive decline exhibited by a well-matched, placebo-treated group. Over a battery of cognitive tests, indomethacin patients improved 1.3 (±1.8), whereas placebo patients declined 8.4 (±2.3)—a significant difference (p< 0.003). Caveats include adverse reactions to indomethacin and the limited scale of the trial.

Methamphetamine in large doses decreases striatal tyrosine hydroxylase activity. This effect is prevented by neuroleptic agents such as chlorpromazine and haloperidol which would suggest that released dopamine may be involved in the response. To test this hypothesis, we have altered dopamine synthesis with a-methyl-p-tyrosine and l-Dopa and found that dopamine synthesis is necessary for the observed depression of striatal TH activity by methamphetamine. In the adrenal gland, however, the increase in TH activity by methamphetamine is not prevented by inhibition of catecholamine synthesis. It is possible that released dopamine may be inhibiting TH activity by activation of pre- or postsynaptic dopamine receptors in the neostriatum resulting in activation of the neuronal feedback pathway or released dopamine may act on dendrodendritic autoreceptors in the substantia nigra.