LBTM: Listen-before-Talk Protocol for Multiclass UHF RFID Networks.

Radio Frequency Identification (RFID) is considered one of the pioneering technologies of the Internet of Things (IoT). It allows to bind physical environments to information processing systems, adding new capabilities like automatic inventorying, location, or sensing with batteryless tags. Indeed, many data flows of physical objects can be tracked using this technology, and it is common to find heterogeneous traffics present in the same facility, each managed by different sets of readers. For example, in a grocery store, typically we have two kinds of readers: those carrying out a continuous inventory, whose goal is knowing the contents of the shelves as accurately as possible; and a set of checking-out readers at exit gates for the billing process that has to minimize the waiting time of customers. Another example of multiclass traffic is a hospital, where new families of sensing tags allow staff to wirelessly monitor patients-which obviously must be done as a priority-and coexist with other readers aimed at precisely knowing the location of equipment or drugs. Even with the same goal, there could be readers requiring different setups, for example in the hospital case, readers located at doors for inventorying purposes have a short time available to identify passing-by objects or people, and thus they have to work with a higher priority than regular readers performing inventorying tasks. In this work, we investigate a modification of the standard listen-before-talk (LBT) protocol for RFID networks which can support this kind of multipriority environment, by offering different qualities of service to each traffic. Results demonstrate that by tuning the protocol setup, it is possible to establish a trade-off between the performance of each traffic. This is shown for the two cited examples, the grocery shop and the hospital, using a simulation tool allowing us to implement a full-scale RFID model. In addition, we present a greedy mechanism for online reader setup. Instead of selecting offline a hard priority level, this greedy algorithm is able to adapt the priority to achieve the required quality-of-service (QoS) level.

Conformational dynamics and alignment properties of loop lanthanide-binding-tags (LBTs) studied in interleukin-1ß.

Encodable lanthanide binding tags (LBTs) have become an attractive tool in modern structural biology as they can be expressed as fusion proteins of targets of choice. Previously, we have demonstrated the feasibility of inserting encodable LBTs into loop positions of interleukin-1ß (Barthelmes et al. in J Am Chem Soc 133:808-819, 2011). Here, we investigate the differences in fast dynamics of selected loop-LBT interleukin-1ß constructs by measuring 15N nuclear spin relaxation experiments. We show that the loop-LBT does not significantly alter the dynamic motions of the host protein in the sub-τc-timescale and that the loop-LBT adopts a rigid conformation with significantly reduced dynamics compared to the terminally attached encodable LBT leading to increased paramagnetic alignment strength. We further analyze residual dipolar couplings (RDCs) obtained by loop-LBTs and additional liquid crystalline media to assess the applicability of the loop-LBT approach for RDC-based methods to determine structure and dynamics of proteins, including supra-τc dynamics. Using orthogonalized linear combinations (OLCs) of RDCs and Saupe matrices, we show that the combined use of encodable LBTs and external alignment media yields up to five linear independent alignments.

Towards Harmonious Coexistence in the Unlicensed Spectrum: Rational Cooperation of Operators.

5G New Radio (NR) operating in the unlicensed spectrum is accelerating the Fourth Industrial Revolution by supporting Internet of Things (IoT) networks or Industrial IoT deployments. Specifically, LTE-Advanced (LTE-A) is looking to achieve spectrum integration through coexistence with multi-radio access technology (RAT) systems in the same unlicensed bands with both licensed-assisted and stand-alone access. The listen-before-talk (LBT) mechanism is mainly considered to enable an LTE operator to protect other incumbent unlicensed systems. In this article, we investigate the behaviors of multiple LTE operators along with the deployment of WiFi networks in the unlicensed spectrum from both short- and long-term points of view. In countries without mandatory LBT requirements, we show that an LTE operator is susceptible to collusion with another LTE operator, thus exploiting scarce spectrum resources by deceiving other wireless networks into thinking that channels are always busy; hence, mandatory usage of LTE with LBT is highly recommended at national level to achieve harmonious coexistence in the unlicensed spectrum. We discuss several possible coexistence scenarios to resolve the operator's dilemmaas well as to improve unlicensed spectrum efficiency among multi-RAT systems, which is viable in the near future.

DESI-TQ-MS imaging for ex vivo brain biodistribution assessment: evaluation of LBT-999, a ligand of the dopamine transporter (DAT).

BACKGROUND: Selection of the most promising radiotracer candidates for radiolabeling is a difficult step in the development of radiotracer pharmaceuticals, especially for the brain. Mass spectrometry (MS) is an alternative to study ex vivo the characteristics of candidates, but most MS studies are complicated by the pharmacologic doses injected and the dissection of regions to study candidate biodistribution. In this study, we tested the ability of a triple quadrupole analyzer (TQ LC-MS/MS) to quantify low concentrations of a validated precursor of a radiotracer targeting the DAT (LBT-999) in dissected regions. We also investigated its biodistribution on brain slices using MS imaging with desorption electrospray ionization (DESI) coupled to time-of-flight (TOF) vs. TQ mass analyzers. RESULTS: TQ LC-MS/MS enabled quantification of LBT-999 injected at sub-tracer doses in dissected striata. DESI-MS imaging (DESI-MSI) with both analyzers provided images of LBT-999 biodistribution on sagittal slices that were consistent with positron emission tomography (PET). However, the TOF analyzer only obtained biodistribution images at a high injected dose of LBT-999, while the TQ analyzer provided biodistribution images at lower injected doses of LBT-999 with a better signal-to-noise ratio. It also allowed simultaneous visualization of endogenous metabolites such as dopamine. CONCLUSIONS: Our results show that LC-TQ MS/MS in combination with DESI-MSI can provide important information (biodistribution, specific and selective binding) that can facilitate the selection of the most promising candidates for radiolabeling and support the development of radiotracers.

Suspend or amend? Randomized controlled trial on neuropsychological rehabilitation for epilepsy: A COVID-19 impact.

COVID-19 caused devastating effects of human loss and suffering along with disruption in clinical research, forcing reconceptualization and modification of studies. This paper attempts to outline the steps followed and detail the modifications undertaken to deal with the impacts of the pandemic on the first ongoing randomized controlled trial on effectiveness of neuropsychological rehabilitation in adult patients with drug-resistant epilepsy in India. All modifications were based on evolving guidelines and circumstantial context and were planned, reviewed and approved by important stakeholders. Results obtained from the trial need to be interpreted and analysed within this context. These modifications have implications for wider outreach of neuropsychology services in India.

How norms concerning maternity, femininity and cisgender increase stress among lesbians, bisexual women and transgender people with a fear of childbirth.

OBJECTIVE: To explore and describe norms concerning maternity, femininity and cisgender in lesbian and bisexual women and transgender people (LBT) assigned female at birth, with an expressed fear of childbirth (FOC). DESIGN: Semi-structured interviews were conducted with self-identified LBT people with an expressed FOC. PARTICIPANTS: 17 self-identified LBT people participated. 15 had an expressed FOC, and two were non-afraid partners. FINDINGS: Participants described how their FOC was related to ideals of "the primal woman", including ideals of a natural birth. They also described stress in relation to expectations of gaining a feminine-coded body during pregnancy and of being related to as feminine women. KEY CONCLUSIONS: Maternity ideals, and the ideal of the "natural" birth, can be particularly stressful on those who fear childbirth. Norms concerning femininity and cisgender can contribute to FOC among those who do not comfortably conform with feminine body ideals or feminine gender expressions. IMPLICATION FOR PRACTICE: Treatments of FOC must be designed to acknowledge whether and how norms concerning maternity, femininity and cisgender affect the individual's FOC.

Wireless Coexistence of Cellular LBT Systems and BLE 5.

The 2.4 GHz spectrum is home to several Radio Access Technologies (RATs), including ZigBee, Bluetooth Low Energy (BLE), and Wi-Fi. Accordingly, the technologies' spectrum-sharing qualities have been extensively studied in literature. License-Assisted Access (LAA) Listen-Before-Talk (LBT) has been identified in technical reports as the foundation for the channel access mechanism for 5G New Radio-Unlicensed (NR-U) operating in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band. The introduction of NR-U into this band raises new concerns regarding coexistence of the newcomer with traditional incumbents. This article reports an investigation of BLE 5 and cellular LBT coexisting systems by means of empirical evaluation. The importance of this study stems from that the studied LBT mechanism is indicative of how 5G NR-U would perform in the 2.4 GHz band. Tests were performed in conformity with the American National Standards Institute (ANSI) C63.27 standard for evaluation of wireless coexistence, and results were reported in terms of throughput and interframe delays. In accordance with the standard and under different BLE physical layers (PHYs) and LBT priority classes, three setups were investigated. These pertain to the three tiers of evaluation, which correspond to the criticality of the device under test. Results demonstrated how BLE throughput dropped as the intended-to-unintended signal ratio decreased, and LBT classes exhibited a diminishing effect as the class priority descended. Long Range BLE PHY was found to sustain longer gap times (i.e., delay) than the other two PHYs; however, it showed less susceptibility to interference. Results also demonstrated that low data rate BLE PHYs hindered the LBT throughput performance since they correspond to longer airtime durations.

Fully automated radiosynthesis of [18F]LBT999 on TRACERlab FXFN and AllinOne modules, a PET radiopharmaceutical for imaging the dopamine transporter in human brain.

BACKGROUND: Fluorine labelled 8-((E)-4-fluoro-but-2-enyl)-3ß-p-tolyl-8-aza-bicyclo[3.2.1]octane-2ß-carboxylic acid methyl ester ([18F]LBT999) is a selective radioligand for the in vivo neuroimaging and quantification of the dopamine transporter by Positron Emission Tomography (PET). [18F]LBT999 was produced on a TRACERlab FXFN for the Phase I study but for Phase III and a potent industrial production transfer, production was also implemented on an AllinOne (AIO) system requiring a single use cassette. Both production methods are reported herein. RESULTS: Automation of [18F]LBT999 radiosynthesis on FXFN was carried out in 35% yield (decay-corrected) in 65 min (n = 16), with a radiochemical purity higher than 99% and a molar activity of 158 GBq/µmol at the end of synthesis. The transfer to the AIO platform followed by optimizations allowed the production of [18F]LBT999 in 32.7% yield (decay-corrected) within 48 min (n = 5), with a radiochemical purity better than 98% and a molar activity above 154 GBq/µmol on average at the end of synthesis. Quality controls of both methods met the specification for clinical application. CONCLUSION: Both modules allow efficient and reproducible radiosynthesis of [18F]LBT999 with good radiochemical yields and a reasonable synthesis time. The developments made on AIO, such as its ability to meet pharmaceutical criteria and to more easily comply with GMP requirements, make it an optimal approach for the potent industrial production of [18F]LBT999 and future wider use.

5G NR-U: Homogeneous Coexistence Analysis.

Current technical reports indicate License-Assisted Access (LAA) Listen-Before-Talk (LBT) as the preferred channel access scheme for the upcoming 5G New Radio-Unlicensed. Various studies have examined heterogeneous coexistence of WiFi/LTE-LAA systems. This paper investigates the homogeneous coexistence of intra-network LAA-LBT devices operating in dense deployment scenarios. Results relevant to ETSI-specified priority classes are reported in terms of channel utilization, collision probability, and channel access delay. The framework presented in this paper is then employed to investigate wireless coexistence in a 5G-enabled intensive care unit employing remote patient monitoring over 5G NR-U.

Identification and Characterization of an Arabidopsis thaliana Mutant lbt With High Tolerance to Boron Deficiency.

Boron (B) is an essential micronutrient of plants. In the present study, we characterized an Arabidopsis mutant lbt with significant low-boron tolerance that was identified based on our previous mapping of QTL for B efficiency in Arabidopsis. Multiple nutrient-deficiency analyses point out that lbt mutant is insensitive to only B-limitation stress. Compared with wild-type Col-0, the fresh weight, leaf area, root length and root elongation rate of lbt mutant were significantly improved under B deficiency during vegetative growth. lbt mutant also showed the improvements in plant height, branches and inflorescences compared with Col-0 during the reproductive stage under B limitation. Ultrastructure analysis of the leaves showed that starch accumulation in lbt mutant was significantly diminished compared with Col-0. Furthermore, there were no significant differences in the expression of transporter-related genes and B concentrations between Col-0 and lbt mutant under both normal B and low-B conditions. These results suggest that lbt mutant has a lower B demand than Col-0. Genetic analysis suggests that the low-B tolerant phenotype of lbt mutant is under the control of a monogenic recessive gene. Based on the high-density SNP linkage genetic map, only one QTL for low-B tolerance was mapped on chromosome 4 between 10.4 and 14.8 Mb. No any reported B-relative genes exist in the QTL interval, suggesting that a gene with unknown function controls the tolerance of lbt to B limitation. Taken together, lbt is a low-B tolerant mutant that does not depend on the uptake or transport of B and is controlled by a monogenic recessive gene mapped on chromosome 4, and cloning and functional analysis of LBT gene are expected to reveal novel mechanisms for plant resistance to B deficiency.

On the Coexistence of LTE-LAA in the Unlicensed Band: Modeling and Performance Analysis.

Long term evolution (LTE) technology leveraging the unlicensed band is anticipated to provide a solution for the challenges stemming from the rapid growth of mobile wireless services, the scarcity of available licensed spectrum, and the expected significant increase in mobile data traffic. Ensuring fair operation in terms of spectrum sharing with current unlicensed spectrum incumbents is a key concern relative to the success and viability of Unlicensed LTE (U-LTE). This paper addresses the problem of modeling and evaluating the coexistence of LTE license-assisted-access in the unlicensed band. The paper presents a novel analytical model using Markov chain to accurately model the LAA listen-before-talk scheme, as specified in the final technical specification 36.213 of 3GPP release 13 and 14. Furthermore, model validation is demonstrated through numerical and simulation results comparison. Model performance evaluation is examined and contrasted with IEEE 802.11 distributed coordination function. Finally, a comprehensive coexistence performance analysis is conducted for both homogeneous and heterogeneous network scenarios and coexistence results are presented and discussed herein.

Noninvasive detection of lipids in atherosclerotic plaque using ultrasound thermal strain imaging: in vivo animal study.

OBJECTIVES: This study sought to examine the feasibility of in vivo detection of lipids in atherosclerotic plaque (AP) by ultrasound (US) thermal (or temporal) strain imaging (TSI). BACKGROUND: Intraplaque lipid content is thought to contribute to plaque stability. Lipid exhibits a distinctive physical characteristic of temperature-dependent US speed compared with water-bearing tissues. As tissue temperature changes, US radiofrequency (RF) echoes shift in time of flight, which produces an apparent strain (thermal or temporal strain [TS]). METHODS: US heating-imaging pulse sequences and transducers were designed and integrated into commercial US scanners for US-TSI of arterial segments. US-RF data were collected while gradually increasing tissue temperature. Phase-sensitive speckle tracking was applied to reconstruct TS maps coregistered to B-scans. Segments from injured atherosclerotic and uninjured nonatherosclerotic common femoral arteries (CFA) in cholesterol-fed New Zealand rabbits, and segments from control normal diet-fed rabbits (N =14) were scanned in vivo at different time points up to 12 weeks. RESULTS: Lipid-rich atherosclerotic lesions exhibited distinct positive TS (+0.19 ± 0.08%) compared with that in nonatherosclerotic (-0.10 ± 0.13%) and control (-0.09 ± 0.09%) segments (p < 0.001). US-TSI enabled serial monitoring of lipids during atherosclerosis development. The coregistered set of morphological and compositional information of US-TSI showed good agreement with histology. CONCLUSIONS: US-TSI successfully detected and longitudinally monitored lipid progression in atherosclerotic CFA. US-TSI of relatively superficial arteries may be a modality that could be integrated into a commercial US system for noninvasive lipid detection in AP.

A novel Ebola virus expressing luciferase allows for rapid and quantitative testing of antivirals.

Ebola virus (EBOV) causes a severe hemorrhagic fever with case fatality rates of up to 90%, for which no antiviral therapies are available. Antiviral screening is hampered by the fact that development of cytopathic effect, the easiest means to detect infection with wild-type EBOV, is relatively slow. To overcome this problem we generated a recombinant EBOV carrying a luciferase reporter. Using this virus we show that EBOV entry is rapid, with viral protein expression detectable within 2 h after infection. Further, luminescence-based assays were developed to allow highly sensitive titer determination within 48 h. As a proof-of-concept for its utility in antiviral screening we used this virus to assess neutralizing antibodies and siRNAs, with significantly faster screening times than currently available wild-type or recombinant viruses. The availability of this recombinant virus will allow for more rapid and quantitative evaluation of antivirals against EBOV, as well as the study of details of the EBOV life cycle.