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Abstract Background There is an increasing interest in utilizing tau PET to identify patients early in Alzheimer’s disease (AD). In this work, a temporal lobe composite (Eτ) volume of interest (VOI) was evaluated in a longitudinal flortaucipir cohort and compared to a previously described global neocortical VOI. In a separate autopsy-confirmed study, the sensitivity of the Eτ VOI for identifying intermediate (B2) neurofibrillary tangle (NFT) pathology was evaluated. Methods A total of 427 subjects received flortaucipir, florbetapir, MRI, and cognitive evaluation at baseline and 18 months. In a separate autopsy study, 67 subjects received ante-mortem flortaucipir scans, and neuropathological findings were recorded according to NIA-AA recommendations by two experts. Two VOIs: Eτ comprising FreeSurfer volumes (bilateral entorhinal cortex, fusiform, parahippocampal, and inferior temporal gyri) transformed to MNI space and a previously published global AD signature-weighted neocortical VOI (ADsignature) (Devous et al., J Nucl Med 59:937–43, 2018), were used to calculate SUVr relative to a white matter reference region (PERSI) (Southekal et al., J Nucl Med Off Publ Soc Nucl Med 59:944–51, 2018). SUVr cutoffs for positivity were determined based on a cohort of young, cognitively normal subjects. Subjects were grouped based on positivity on both VOIs (Eτ+/ADsignature+; Eτ+/ADsignature–; Eτ−/ADsignature−). Groupwise comparisons were performed for baseline SUVr, 18-month changes in SUVr, neurodegeneration, and cognition. For the autopsy study, the sensitivity of Eτ in identifying intermediate Braak pathology (B2) subjects was compared to that of AD signature-weighted neocortical VOI. The average surface maps of subjects in the Eτ+/ADsignature− group and B2 NFT scores were created for visual evaluation of uptake. Results Sixty-four out of 390 analyzable subjects were identified as Eτ+/ADsignature–: 84% were Aβ+, 100% were diagnosed as MCI or AD, and 59% were APOE ε4 carriers. Consistent with the hypothesis that Eτ+/ADsignature– status reflects an early stage of AD, Eτ+/ADsignature– subjects deteriorated significantly faster than Eτ–/ADsignature – subjects, but significantly slower than Eτ+/ADsignature+ subjects, on most measures (i.e., change in ADsignature SUVr, Eτ ROI cortical thickness, and MMSE). The ADsignature VOI was selective for subjects who came to autopsy with a B3 NFT score. In the autopsy study, 12/15 B2 subjects (including 10/11 Braak IV) were Eτ+/ADsignature–. Surface maps showed that flortaucipir uptake was largely captured by the Eτ VOI regions in B2 subjects. Conclusion The Eτ VOI identified subjects with elevated temporal but not global tau (Eτ+/ADsignature–) that were primarily Aβ+, APOE ε4 carriers, and diagnosed as MCI or AD. Eτ+/ADsignature– subjects had greater accumulation of tau, greater atrophy, and higher decline on MMSE in 18 months compared to Eτ−/ADsignature− subjects. Finally, the Eτ VOI identified the majority of the intermediate NFT score subjects in an autopsy-confirmed study. As far as we know, this is the first study that presents a visualization of ante-mortem FTP retention patterns that at a group level agree with the neurofibrillary tangle staging scheme proposed by Braak. These findings suggest that the Eτ VOI may be sensitive for detecting impaired subjects early in the course of Alzheimer’s disease.

Abstract INTRODUCTION Alzheimer's disease (AD) is characterized by the presence of both amyloid and tau pathology. In vivo diagnosis can be made with amyloid and tau positron emission tomography (PET) imaging. Emergent evidence supports that amyloid and tau accumulation are associated and that amyloid accumulation may precede that of tau. This report further investigates the relationship between amyloid and tau to assess whether elevated cortical tau can predict elevated amyloid in participants with early symptomatic AD. METHODS Florbetapir F18 and flortaucipir F18 uptake were evaluated from baseline PET scans collected in three multi‐center studies with cognitively impaired participants, including A05 (N = 306; NCT02016560), TB (N = 310; TRAILBLAZER‐ALZ; NCT03367403), and TB2 (N = 1165; TRAILBLAZER‐ALZ 2; NCT04437511). Images were assessed using visual and quantitative approaches to establish amyloid (A+) and tau (T+) positivity, as well as a combination method (tauVQ) to establish T+. Associations between global amyloid and tau were evaluated with positive and negative predictive values (PPV, NPV) and likelihood ratios (LR+, LR–). Predictive values within subgroups according to ethnicity, race, cognitive score, age, and sex were also evaluated. The relationship between regional tau (four target and two reference regions were tested) and global amyloid was investigated in A05 participant scans using receiver‐operating characteristic (ROC) curves. RESULTS PPV for amyloid positivity was ≥93% for all three trials using various A+ and T+ definitions, including visual, quantitative, and combination methods. Population characteristics did not have an impact on A+ predictability. Regional analyses (early tau (Eτ) volume of interest (VOI), temporal, parietal, frontal) revealed significant area under the ROC curve in Eτ VOI compared to frontal region, regardless of reference region and consistent among visual and quantitative A+ definitions (p < 0.001). DISCUSSION These findings suggest that a positive tau PET scan is associated (≥93%) with amyloid positivity in individuals with early symptomatic AD, with the potential benefits of reducing clinical trial and health care expenses, radiation exposure, and participant time. Highlights Positron emission tomography (PET) evaluates candidates for Alzheimer's disease (AD) research. A positive tau PET scan is associated (≥93%) with amyloid positivity. A positive amyloid PET is not necessarily associated with tau positivity. Tau PET could be the sole diagnostic tool to confirm candidates for AD trials.

Sigillography is regarded in the Czech Republic as a traditional academic discipline. The history of the field shows, however, that it has yet to welcome the production of a seminal, far‑reaching work. In earlier time, ecclesiastical sigillography was largely neglected, seeing little development until recent decades. The first analytical studies are now appearing which attempt to interpret sigillographical materials in a broader historical context. Researchers are now also turning their attention to modern materials, giving rise to specific terminological and methodological difficulties. This study offers a brief outline of developments in sigillography in the Czech Republic, and particularly ecclesiastical sigillography. In this specific case, it describes the research objectives and the questions being asked, while outlining proposed solutions.

The recent progress in Wireless sensor networks is contributed by improvisation in research activities in the domain of embedded system and radio communication. Localization is one of the most important challenge in WSNs, in view of the fact that it plays a significant part in many applications, e.g., explore, catastrophe assistance, rescue operations, tracking the target and multiple tasks in smart milieus. Localization of node involves the activity of monitoring events, group discussion between the nearby sensors, routing the necessary information to the destination by keeping network coverage in check. In this research paper, Received Signal Strength Indicator (RSSI) based trilateration algorithm is proposed for localizing a blind node present in the network with minimal localization error. The position coordinates of the blind node is estimated based on the distance estimates and corresponding position coordinates of the anchor nodes present in the network. This work was performed in Contiki-OS with the help of built-in simulator COOJA. Based on the simulation results conducted with random position coordinates, the obtained localization error is found to be approximately 1.9 meters. The obtained error margin though not stringently accurate, but is acceptable, considering the environment in which the nodes are deployed which experiences varying channel characteristics, multipath fading and shadowing.

Introduction: Hypoglycemia is a common metabolic problem in the neonatal period especially in the presence of settings like prematurity, small for gestational age babies and sepsis. Episodes of asymptomatic hypoglycemia may occur in term neonates without apparent risk factors. Aim: This study was conducted to estimate the incidence of hypoglycemia in healthy, intramural, singleton full term neonates and to correlate the above incidence with maternal factors like parity, mode of delivery and time of initiation of breast feeding after birth. Materials and Methods: A hospital based, prospective longitudinal study involving healthy, term, asymptomatic neonates. Blood glucose values were measured at 1, 6, 24 and 48 hours of life. Results: The overall incidence of hypoglycemia was 10 % in asymptomatic, healthy term newborns. All the hypoglycemic episodes occurred in the first 24 hours of life. 23.07% of neonates born to primiparous mothers had hypoglycemia, against 5.4% neonates born to multiparous mothers (p 1 hour after delivery (16.67%) than when breast feeding was initiated within one hour of delivery (7.89%). Conclusion: Asymptomatic hypoglycemia occurred in about 10% of healthy, full term neonates; primiparity and delayed initiation of breast feeding > 1 hour are noted as additional risk factors.

The recent progress in Wireless sensor networks is contributed by improvisation in research activities in the domain of embedded system and radio communication. Localization is one of the most important challenge in WSNs, in view of the fact that it plays a significant part in many applications, e.g., explore, catastrophe assistance, rescue operations, tracking the target and multiple tasks in smart milieus. Localization of node involves the activity of monitoring events, group discussion between the nearby sensors, routing the necessary information to the destination by keeping network coverage in check. In this research paper, Received Signal Strength Indicator (RSSI) based trilateration algorithm is proposed for localizing a blind node present in the network with minimal localization error. The position coordinates of the blind node is estimated based on the distance estimates and corresponding position coordinates of the anchor nodes present in the network. This work was performed in Contiki-OS with the help of built-in simulator COOJA. Based on the simulation results conducted with random position coordinates, the obtained localization error is found to be approximately 1.9 meters. The obtained error margin though not stringently accurate, but is acceptable, considering the environment in which the nodes are deployed which experiences varying channel characteristics, multipath fading and shadowing. [ABSTRACT FROM AUTHOR]

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